sirolimus and Ischemia

Renal tubular cells die by apoptosis as well as necrosis in experimental models of ischemic and toxic acute renal failure as well as in humans with acute tubular necrosis. It is not yet possible, however, to determine the relative contribution of these two forms of cell death to loss of renal tubular cells in acute tubular necrosis. The beneficial effect of administering growth factors to animals with acute tubular necrosis is probably related to the potent antiapoptotic (survival) effects of growth factors as well as to their proliferative effects. Rapamycin inhibits both of these effects of growth factors and delays the recovery of renal function after acute tubular necrosis by inhibiting renal tubular cell regeneration and by increasing renal tubular cell loss by apoptosis. The administration of caspase inhibitors ameliorates ischemia-reperfusion injury in multiple organs including the kidney. However, the extent to which this protective effect of caspase inhibition is caused by reduced intrarenal inflammation, or by amelioration of renal tubular cell loss due to apoptosis, remains uncertain. In addition to caspase inhibition, the apoptotic pathway offers many potential targets for therapeutic interventions to prevent renal tubular cell apoptosis.

Topics: Acute Kidney Injury; Apoptosis; Caspase Inhibitors; Cell Adhesion; Cisplatin; Growth Substances; Guanosine Triphosphate; Humans; Ischemia; Kidney Tubules; Necrosis; Sirolimus

The performance of sirolimus-coated devices has not been studied in patients with chronic limb-threatening ischemia patients. PRESTIGE aims to investigate the 6-month efficacy and safety profile of the Selution Sustained Limus Release (SLR) sirolimus-eluting balloon for treatment of TASC II C and D tibial occlusive lesions in patients with CLTI.. PRESTIGE is a pilot prospective, nonrandomized, single-arm, multi-investigator, single-center clinical study. Endpoints were adverse event-free survival at 1 month, technical success rate, primary tibial patency at 6 months, limb salvage success, target lesion revascularization (TLR), and amputation free survival (AFS).. A total of 25 patients were included. There were 17 (68.0%) males; mean age, 63.7±9.73 years. CLTI severity was based on the Rutherford scale (R5=25/25; 100.0%). Significant comorbidities included diabetes mellitus (n=22; 88.0%) and end-stage renal failure (n=11; 44.0%). A total of 33 atherosclerotic lesions were treated (TASC II D=15 (45.5%)). Mean lesion length treated was 191±111 mm. Technical success was 100%. Primary tibial patency at 6 months was 22/27 (81.5%) and freedom from clinically driven TLR was 25/30 (83.3%). AFS was 21/25 (84.0%; 3 deaths and 1 major lower extremity amputation). Mean Rutherford score improved from 5.00 at baseline to 1.14±2.10 (p<0.05) at 6 months. There was a wound healing rate of 13/22 (59.1%) and 17/21 (81.0%) at 3 and 6 months respectively.. Selution SLR drug-eluting balloon is a safe and efficacious modality in treating complex tibial arterial occlusive lesions in what is an otherwise frail cohort of CLTI patients, with a high prevalence of diabetes and end-stage renal failure. Technical and clinical success rates are high and 6-month target lesion patency and AFS are more than satisfactory.

Topics: Aged; Angioplasty, Balloon; Drug-Eluting Stents; Humans; Ischemia; Limb Salvage; Male; Middle Aged; Peripheral Arterial Disease; Popliteal Artery; Prospective Studies; Sirolimus; Treatment Outcome; Vascular Patency

Topics: Aged; Aged, 80 and over; Angioplasty, Balloon; Cardiovascular Agents; Coated Materials, Biocompatible; Constriction, Pathologic; Delayed-Action Preparations; Female; Femoral Artery; Germany; Humans; Ischemia; Limb Salvage; Male; Middle Aged; Peripheral Arterial Disease; Popliteal Artery; Prospective Studies; Recovery of Function; Severity of Illness Index; Sirolimus; Time Factors; Treatment Outcome; Vascular Patency

The authors sought to report the wound healing outcomes, health-related quality-of-life changes and quality-adjusted life-years (QALYs) gain in the 2 treatment arms of the ACHILLES (Comparing Angioplasty and DES in the Treatment of Subjects With Ischemic Infrapopliteal Arterial Disease) multicenter randomized trial.. The ACHILLES randomized trial has previously shown that sirolimus-eluting stents (SES) may achieve lower vessel restenosis and higher event-free survival rates compared with plain balloon angioplasty (PTA) for infrapopliteal lesions.. A total of 200 patients were randomly assigned between SES and PTA for the treatment of infrapopliteal arterial occlusive lesions. Progression of wound healing was serially assessed by digital photography. Health-related quality-of-life scores were assessed with the self-administered EQ-5D questionnaire up to 1 year from randomization. QALYs gained were calculated with a standard multiplicative model using distribution-free Bayesian modeling.. In total, 109 open wounds (n = 54 in SES; n = 55 in PTA) were documented at baseline. At 6 months, wound volume reduction (%) was significantly higher in the SES group (95% healing [95% confidence interval (CI): 80% to 99%] compared with 60% healing [95% CI: 13% to 90%] in the PTA group; p = 0.048). At 1 year, rates of complete wound closure were higher in the case of SES (72.9% vs. 55.6% closed wounds in PTA; p = 0.088). The recorded weighted EQ-5D score improved significantly up to 1 year in case of SES (p < 0.0001), but not in case of PTA. There was a trend of more QALYs gained with SES compared with PTA up to 1 year after randomization. Relative QALY gain was 0.10 (95% CI: -0.01 to 0.21; p = 0.08) in the whole study and 0.17 (95% CI: -0.03 to 0.35; p = 0.09) in the wound subgroups comparison.. Infrapopliteal SES accelerates wound healing and may improve quality of life compared with PTA. (Comparing Angioplasty and DES in the Treatment of Subjects With Ischemic Infrapopliteal Arterial Disease [ACHILLES]; NCT00640770).

Topics: Aged; Angioplasty, Balloon; Arterial Occlusive Diseases; Drug-Eluting Stents; Female; Humans; Ischemia; Leg; Male; Peripheral Arterial Disease; Popliteal Artery; Prospective Studies; Quality of Life; Sirolimus; Wound Healing

Critical limb ischemia, the most severe form of peripheral arterial disease, results in extremity amputation if left untreated. Endovascular recanalization of stenotic or occluded infrapopliteal arteries has recently emerged as an effective form of therapy, although the duration of patency is typically limited by restenosis. Recently, it has been suggested that drug-eluting stents originally developed for the coronary arteries might also be effective in preventing restenosis in the infrapopliteal arteries. This prospective, randomized, controlled clinical trial tested the hypothesis that treatment of infrapopliteal arterial occlusive lesions with an everolimus-eluting stent (Xience V) would provide superior patency to treatment with a bare-metal stent (Multi-Link Vision).. A sample size of 140 patients was planned to be enrolled at five European investigative sites. The primary end point was arterial patency at 12 months, defined as the absence of ≥50% restenosis based on quantitative analysis of contrast angiography.. Between March of 2008 and September of 2009, 74 patients were treated with Xience V and 66 patients were treated with Vision. After 12 months, the primary patency rate after treatment with Xience V was 85% compared with 54% after treatment with Vision (P = .0001). Treatment with Xience V significantly reduced mean in-stent diameter stenosis (21% ± 21% vs 47% ± 27%; P < .0001) and mean in-stent late lumen loss (0.78 ± 0.63 vs 1.41 ± 0.89 mm; P = .001). There were no differences in the percentage of patients receiving a designation of Rutherford class 0 or 1 at the 12-month follow-up visit (56% for Vision, vs 60% for Xience V; P = .68). Major extremity amputations were rare in both groups (two for Vision and one for Xience V). The use of the Xience V stent significantly reduced the need for repeat intervention: freedom from target lesion revascularization was 91% for Xience V vs 66% for Vision (P = .001).. Treatment of the infrapopliteal occlusive lesions of critical limb ischemia with everolimus-eluting stents reduces restenosis and the need for reintervention compared with bare metal stents.

Topics: Aged; Aged, 80 and over; Amputation, Surgical; Angioplasty; Arterial Occlusive Diseases; Cardiovascular Agents; Constriction, Pathologic; Critical Illness; Drug-Eluting Stents; Europe; Everolimus; Female; Humans; Ischemia; Kaplan-Meier Estimate; Limb Salvage; Male; Metals; Middle Aged; Popliteal Artery; Prospective Studies; Prosthesis Design; Radiography; Recurrence; Risk Assessment; Risk Factors; Sirolimus; Stents; Time Factors; Treatment Outcome; Vascular Patency

The study investigated the long-term clinical impact of sirolimus-eluting stents (SES) in comparison with bare-metal stents (BMS) in treatment of focal infrapopliteal lesions.. There is evidence that SES reduce the risk of restenosis after percutaneous infrapopliteal artery revascularization. No data from randomized trials are available concerning the clinical impact of this finding during long-term follow-up.. The study extended the follow-up period of a prospective, randomized, multicenter, double-blind trial comparing polymer-free SES with placebo-coated BMS in the treatment of focal infrapopliteal de novo lesions. The main study endpoint was the event-free survival rate defined as freedom from target limb amputation, target vessel revascularization, myocardial infarction, and death. Secondary endpoints include amputation rates, target vessel revascularization, and changes in Rutherford-Becker class.. The trial included 161 patients. The mean target lesion length was 31 ± 9 mm. Thirty-five (23.3%) patients died during a mean follow-up period of 1,016 ± 132 days. The event-free survival rate was 65.8% in the SES group and 44.6% in the BMS group (log-rank p = 0.02). Amputation rates were 2.6% and 12.2% (p = 0.03), and target vessel revascularization rates were 9.2% and 20% (p = 0.06), respectively. The median (interquartile range) improvement in Rutherford-Becker class was -2 (-3 to -1) in the SES group and -1 (-2 to 0) in the BMS group, respectively (p = 0.006).. Long-term event-free survival, amputation rates, and changes in Rutherford-Becker class after treatment of focal infrapopliteal lesions are significantly improved with SES in comparison with BMS. (YUKON-Drug-Eluting Stent Below the Knee-Randomised Double-Blind Study [YUKON-BTX]; NCT00664963).

Topics: Aged; Aged, 80 and over; Angioplasty; Antibiotics, Antineoplastic; Double-Blind Method; Drug-Eluting Stents; Female; Humans; Intermittent Claudication; Ischemia; Leg; Male; Middle Aged; Peripheral Arterial Disease; Prospective Studies; Sirolimus

The study investigated the efficacy and safety of a balloon expandable, sirolimus-eluting stent (SES) in patients with symptomatic infrapopliteal arterial disease.. Results of infrapopliteal interventions using balloon angioplasty and/or bare stents are limited by a relatively high restenosis rate, which could be potentially improved by stabilizing the lesion with a SES.. Two hundred patients (total lesion length 27 ± 21 mm) were randomized to infrapopliteal SES stenting or percutaneous transluminal balloon angioplasty (PTA). The primary endpoint was 1-year in-segment binary restenosis by quantitative angiography.. Ninety-nine and 101 patients (mean age 73.4 years; 64% diabetics) were randomized to SES and PTA, respectively (8 crossover bailout cases to SES). At 1 year, there were lower angiographic restenosis rates (22.4% vs. 41.9%, p = 0.019), greater vessel patency (75.0% vs. 57.1%, p =0.025), and similar death, repeat revascularization, index-limb amputation rates, and proportions of patients with improved Rutherford class for SES versus PTA.. SES implantation may offer a promising therapeutic alternative to PTA for treatment of infrapopliteal peripheral arterial disease.

Topics: Aged; Aged, 80 and over; Angioplasty, Balloon, Coronary; Drug-Eluting Stents; Europe; Female; Follow-Up Studies; Humans; Ischemia; Male; Peripheral Arterial Disease; Popliteal Artery; Prospective Studies; Radiography; Sirolimus; Treatment Outcome

Preliminary reports indicate that sirolimus-eluting stents reduce the risk of restenosis after percutaneous infrapopliteal artery revascularization. We conducted a prospective, randomized, multi-centre, double-blind trial comparing a polymer-free sirolimus-eluting stent with a placebo-coated bare-metal stent in patients with either intermittent claudication or critical limb ischaemia who had a de-novo lesion in an infrapopliteal artery.. 161 patients were included in this trial. The mean target lesion length was 31 ± 9 mm. The main study endpoint was the 1-year primary patency rate, defined as freedom from in-stent-restenosis (luminal narrowing of ≥50%) detected with duplex ultrasound if not appropriate with angiography. Secondary endpoints included the 6-month primary patency rate, secondary patency rate, and changes in Rutherford-Becker classification after 1 year. Twenty-five (15.5%) patients died during the follow-up period. One hundred and twenty-five patients reached the 1-year examinations. The 1-year primary patency rate was significantly higher in the sirolimus-eluting stent group (80.6%) than in the bare-metal stent group (55.6%, P= 0.004), and the 1-year secondary patency rates were 91.9 and 71.4% (P= 0.005), respectively. The median (interquartile range) change in Rutherford-Becker classification after 1 year was -2 (-3 to -1) in the sirolimus-eluting stent group and -1 (-2 to 0) in the bare-metal stent group, respectively (P= 0.004).. Mid-term patency rates of focal infrapopliteal lesions are substantially improved with sirolimus-eluting stent compared with bare-metal stent. Corresponding to the technical results, the changes in Rutherford-Becker classification reveal a significant advantage for the sirolimus-eluting stent.

Topics: Aged; Aged, 80 and over; Angioplasty, Balloon; Arterial Occlusive Diseases; Double-Blind Method; Drug-Eluting Stents; Female; Graft Survival; Humans; Intermittent Claudication; Ischemia; Leg; Male; Popliteal Artery; Prospective Studies; Reperfusion; Secondary Prevention; Sirolimus; Treatment Outcome; Tubulin Modulators; Vascular Patency

A comparison was made of sirolimus-eluting stents and bare stents as an effective means of treatment of stenosis in crural arteries. Patients were randomly divided into two groups: (1) patients treated with sirolimus-eluting stents and (2) patients treated with bare stents. Each group consisted of 25 patients, and every patient had one stent implanted. All patients showed symptoms of ischemia of the peripheral arteries, classified according to the Rutherford scale into categories 3, 4, and 5. All patients were examined 24 h before and 24 h and 6 months after the intervention. The results were analyzed according to clinical, hemodynamic, and angiographic criteria. Technically, the procedure was successful in 100% of cases, and both groups presented an equal improvement in clinical and hemodynamic parameters. The follow-up angiographic examination demonstrated a significantly lower rate of restenosis among the sirolimus-eluting stent group (4, 16%) versus the bare stent group (19, 76%) (p < 0.001), with lower target lesion revascularization in 3 (12%) versus 14 (56%) (p < 0.05), respectively. Quantitative angiography demonstrated that all variables used to assess restenosis were superior for sirolimus-eluting stents 6 months after intervention: late lumen loss 0.46 +/- 0.72 versus 1.70 +/- 0.94 (p < 0.001) and minimal lumen diameter 2.25 +/- 0.82 versus 0.99 +/- 1.08 (p < 0.001). Results of this study reveal that the use of sirolimus-eluting stents decreases the risk of restenosis in comparison to standard stents.

Topics: Aged; Aged, 80 and over; Angiography; Arteries; Atherosclerosis; Coronary Restenosis; Drug-Eluting Stents; Female; Humans; Ischemia; Male; Middle Aged; Sirolimus; Stents

To present the 3-year angiographic and clinical results of a prospective registry investigating the performance of sirolimus-eluting stents (SESs) versus bare metal stents (BMSs) for critical limb ischemia (CLI) treatment.. A single-center double-arm prospective registry included patients with CLI who underwent infrapopliteal revascularization with angioplasty and "bailout" use of an SES or BMS. Clinical and angiographic follow-up was scheduled at regular time intervals. Primary clinical and angiographic endpoints included mortality, limb salvage, primary patency, binary angiographic restenosis (ie, >50%), and clinically driven repeat intervention-free survival. Results were stratified according to stent type, and cumulative proportion outcomes were determined by Kaplan-Meier plots. Multivariable Cox proportional-hazards regression analysis was applied to adjust for confounding factors of heterogeneity.. In total, 103 patients were included in the analysis; 41 (75.6% with diabetes) were treated with a BMS (47 limbs; 77 lesions) and 62 (87.1% with diabetes) with an SES (75 limbs; 153 lesions). At 3 years, SES-treated lesions were associated with significantly better primary patency (hazard ratio [HR], 4.81; 95% CI, 2.91-7.94; P < .001), reduced binary restenosis (HR, 0.38; 95% CI, 0.25-0.58; P < .001), and better repeat intervention-free survival (HR, 2.56; 95% CI, 1.30-5.00; P = .006) versus BMS-treated ones. No significant differences were identified between SESs and BMSs with regard to overall 3-year patient mortality (29.3% vs 32.0%; P = .205) and limb salvage (80.3% vs 82.0%; P = .507).. Infrapopliteal application of SESs for CLI significantly improves angiographic long-term patency and reduces infrapopliteal vascular restenosis versus BMSs, thereby lessening the rate of clinically driven repeat interventions.

Topics: Aged; Blood Vessel Prosthesis; Drug-Eluting Stents; Female; Humans; Immunosuppressive Agents; Injections, Intra-Arterial; Ischemia; Leg; Longitudinal Studies; Male; Metals; Popliteal Artery; Radiography; Sirolimus; Treatment Outcome

To report the 1-year angiographic and clinical outcome from a prospective single-center study investigating the infrapopliteal application of sirolimus-eluting versus bare metal stents in patients with critical limb ischemia (CLI) who underwent below-the-knee endovascular revascularization.. Stenting was performed as a bailout procedure for suboptimal angioplasty results (flow-limiting dissection, elastic recoil, or postangioplasty residual stenosis >30%). In the first 29 patients, infrapopliteal stenting was performed with bare metal stents (group B) and with sirolimus-eluting stents in the other 29 patients (group S).. Below-the-knee angioplasty and stenting involved 65 lesions in 40 infrapopliteal arteries of 29 limbs in group B and 66 lesions in 41 infrapopliteal arteries of 29 limbs in group S. Baseline comorbidities (hyperlipidemia and symptomatic cardiac and carotid disease) were more pronounced in group S (p<0.05). At 6 months, sirolimus-eluting stents demonstrated significantly higher primary patency (OR 5.625, 95% CI 1.711 to 18.493, p = 0.004) and decreased in-stent binary restenosis (OR 0.067, 95% CI 0.021 to 0.017, p<0.001) and in-segment binary restenosis (OR 0.229, 95% CI 0.099 to 0.533, p = 0.001). After 1 year, sirolimus-eluting stents were steadily associated with increased primary patency (OR 10.401, 95% CI 3.425 to 31.589, p<0.001) and significantly less in-stent (OR 0.156, 95% CI 0.060 to 0.407, p<0.001) and in-segment (OR 0.089, 95% CI 0.023 to 0.349, p = 0.001) binary restenosis. In addition, sirolimus-eluting stents were associated with significantly fewer cumulative target lesion reinterventions at 6 months (OR 0.057, 95% CI 0.008 to 0.426, p = 0.005) and 1 year (OR 0.238, 95% CI 0.067 to 0.841, p = 0.026). No significant differences between groups B and S were noted at 1 year with respect to mortality (10.3% versus 13.8%, respectively), minor amputation (17.2% versus 10.3%), or limb salvage (100% versus 96%).. The application of sirolimus-eluting stents reduces the restenosis rate in the infrapopliteal arteries and the rate of repeat endovascular procedures the first year after treatment.

Topics: Aged; Angiography, Digital Subtraction; Angioplasty, Balloon; Cardiovascular Agents; Constriction, Pathologic; Female; Follow-Up Studies; Humans; Ischemia; Leg; Male; Metals; Odds Ratio; Popliteal Artery; Prospective Studies; Prosthesis Design; Research Design; Secondary Prevention; Sirolimus; Stents; Time Factors; Treatment Outcome; Vascular Patency

We investigated the safety and efficacy of sirolimus-eluting stents in the treatment of patients with severe below-the-knee' critical limb ischemia.. Between October 2004 and January 2005 we performed 20 percutaneous transluminal angioplasty procedures on 18 patients (7 female, 11 male, mean age 72.8 years), implanting 24 sirolimus-eluting stents. At pre-procedure, 12 patients (66.7%) presented with a Rutherford Category 4, 4 (22.2%) with Category 5 and 2 (11.1%) with Category 6. The majority of patients (72.2%, n=13) were non-smokers and 77.8% (n=14) presented with hypercholesterolemia. Calcification was present in 52.2% (n=12) of lesions. Pre-dilation was performed in half the patients. The majority of lesions (95.7%, n=22) were treated with a single sirolimus-eluting stent. Two patients underwent 2 procedures, each one receiving 2 sirolimus-eluting stents. Clinical examination and quantitative vascular analysis were performed in all patients at discharge and at 6-month follow-up.. Percutaneous transluminal angioplasty was successfully performed on all 18 patients. The mean stent length and stent diameter were 30.29 mm and 3.23 mm, respectively. Mean follow-up was 256 days (170-368 days). At the 6-month follow-up, the minimum lumen diameter as measured by Quantitative Vessel Analysis was 2.39 mm with an attendant LLS of 0.38 mm. The overall 6-month survival and limb salvage rate were 94.4% and 94%, respectively.. Our results suggest that treatment with sirolimus-eluting stents can be considered as an effective and safe treatment of patients with critical ischemia.

Topics: Adult; Aged; Aged, 80 and over; Angioplasty, Balloon; Female; Follow-Up Studies; Humans; Immunosuppressive Agents; Ischemia; Leg; Male; Middle Aged; Prospective Studies; Sirolimus; Stents; Treatment Outcome

Ischemic postconditioning (I-PostC) has a protective effect against acute kidney injury (AKI) induced by limb ischemia-reperfusion (LIR); however, the exact mechanism remains to be elucidated. Our study aims to investigate the potential involvement of high-mobility group box 1 protein (HMGB1) and autophagy in renoprotection generated by I-PostC. A rat model of LIR-induced AKI was established and rats were randomly assigned to five groups: (i) sham-operated control, (ii) I/R, (iii) I/R + I-PostC, (iv) I/R + I-PostC + rapamycin (autophagy activator), and (v) I/R + I-PostC + 3-methyladenine (autophagy inhibitor). Morphological changes in the kidneys were assessed by histology, and ultrastructural changes in renal tubular epithelial cells and glomerular podocytes were observed by transmission electron microscopy. The levels of kidney function parameters, serum inflammatory factors, and autophagy markers were detected. The results showed that the levels of HMGB1, Beclin1, LC3-II/LC3-I, and inflammatory cytokines (TNF-α and IL-6) were significantly higher in the I/R group compared to the sham control in serum and in renal tissues. I-PostC significantly reduced the levels of HMGB1, Beclin1, LC3-II/LC3-I, and inflammatory cytokines in renal tissues and improved renal function. Renal histopathology and ultrastructural observations indicated that I-PostC alleviated renal tissue injury. In addition, rapamycin (autophagy activator) treatment increased the levels of inflammatory cytokine expression levels and decreased renal function, reversed the protective effect of I-PostC against LIR-induced AKI. In conclusion, I-PostC could play a protective role against AKI by regulating the release of HMGB1 and inhibiting autophagy activation.

Topics: Acute Kidney Injury; Animals; Autophagy; Beclin-1; Cytokines; HMGB1 Protein; Ischemia; Ischemic Postconditioning; Rats; Reperfusion; Reperfusion Injury; Sirolimus

Robust activation of mTOR (mammalian target of rapamycin) signaling in diabetes exacerbates myocardial injury following lethal ischemia due to accelerated cardiomyocyte death with cardiac remodeling and inflammatory responses. We examined the effect of rapamycin (RAPA, mTOR inhibitor) on cardiac remodeling and inflammation following myocardial ischemia/reperfusion (I/R) injury in diabetic rabbits. Diabetic rabbits (DM) were subjected to 45 min of ischemia and 10 days of reperfusion by inflating/deflating a previously implanted hydraulic balloon occluder. RAPA (0.25 mg/kg, i.v.) or DMSO (vehicle) was infused 5 min before the onset of reperfusion. Post-I/R left ventricular (LV) function was assessed by echocardiography and fibrosis was evaluated by picrosirius red staining. Treatment with RAPA preserved LV ejection fraction and reduced fibrosis. Immunoblot and real-time PCR revealed that RAPA treatment inhibited several fibrosis markers (TGF-β, Galectin-3, MYH, p-SMAD). Furthermore, immunofluorescence staining revealed the attenuation of post-I/R NLRP3-inflammasome formation with RAPA treatment as shown by reduced aggregation of apoptosis speck-like protein with a caspase recruitment domain and active-form of caspase-1 in cardiomyocytes. In conclusion, our study suggests that acute reperfusion therapy with RAPA may be a viable strategy to preserve cardiac function with the alleviation of adverse post-infarct myocardial remodeling and inflammation in diabetic patients.

Topics: Animals; Diabetes Mellitus; Fibrosis; Inflammation; Ischemia; Mammals; Myocardial Reperfusion Injury; Myocytes, Cardiac; Rabbits; Sirolimus; TOR Serine-Threonine Kinases; Ventricular Remodeling

Clinically unpredictable retention following fat grafting remains outstanding problems because of the unrevealed mechanism of grafted fat survival. The role of autophagy, a process to maintain cellular homeostasis through recycling cellular debris, has yet been to be reported in fat grafting. This study aims to improve the survival of fat grafting through the autophagy. First, the relationship between cell death and autophagy in the early stage of fat grafting was evaluated through immunostaining, RNA sequencing, and western blot. Next, rapamycin, an autophagic agonist, was used for the culturing of adipose-derived stem cells and adipocytes during ischemia. Cell death, autophagy, and reactive oxygen species (ROS) were assayed. Finally, rapamycin was used to assist fat grafting in nude mice. The results demonstrated that the peak of cell death at the early stage of fat grafting was accompanied by a decrease in autophagy. In vitro, during ischemia, 25 nM was confirmed as the optimal dose of rapamycin that reduces cell death with enhanced autophagy and mitophagy, improved mitochondrial quality as well as decreased ROS accumulation. In vivo, promoted mitophagy, alleviated oxidative stress, and decreased cell apoptosis of rapamycin-treated fat grafts were observed in the early stage. In addition, rapamycin increased the survival of fat grafts with increased neovascularization and reduced fibrosis. We suggested that moderate autophagy induced by rapamycin contribute to enhanced ischemic tolerance and long term survival of fat grafts through mitochondrial quality control.

Topics: Animals; Autophagy; Cell Survival; Graft Survival; Ischemia; Mice; Mice, Nude; Reactive Oxygen Species; Sirolimus

Few therapies can reverse the proangiogenic activity of senescent mesenchymal stromal/stem cells (MSCs). In this study, we investigated the effects of rapamycin on the proangiogenic ability of senescent human umbilical cord MSCs (UCMSCs). An in vitro replicative senescent cell model was established in cultured UCMSCs. We found that late passage (P25 or later) UCMSCs (LP-UCMSCs) exhibited impaired proangiogenic abilities. Treatment of P25 UCMSCs with rapamycin (900 nM) reversed the senescent phenotype and notably enhanced the proangiogenic activity of senescent UCMSCs. In a nude mouse model of hindlimb ischemia, intramuscular injection of rapamycin-treated P25 UCMSCs into the ischemic limb significantly promoted neovascularization and ischemic limb salvage. We further analyzed the changes in the expression of angiogenesis-associated genes in rapamycin-primed MSCs and found higher expression of several genes related to angiogenesis, such as VEGFR2 and CTGF/CCN2, in primed cells than in unprimed MSCs. Taken together, our data demonstrate that rapamycin is a potential drug to restore the proangiogenic activity of senescent MSCs, which is of importance in treating ischemic diseases and tissue engineering.

Topics: Animals; Cells, Cultured; Hindlimb; Humans; Ischemia; Limb Salvage; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Mice; Mice, Nude; Neovascularization, Pathologic; Neovascularization, Physiologic; Sirolimus

Topics: Angioplasty, Balloon; Atherosclerosis; Coated Materials, Biocompatible; Humans; Ischemia; Limb Salvage; Peripheral Arterial Disease; Popliteal Artery; Sirolimus; Treatment Outcome; Vascular Patency

Limb ischemia occurs due to obstruction of blood perfusion to lower limbs, a manifestation that is associated with peripheral artery disease (PAD). Angiogenesis is important for adequate oxygen delivery. The present study investigated a potential role for chrysin, a naturally occurring flavonoid, in promoting angiogenesis in hindlimb ischemia (HLI) rat model. Rats were allocated into four groups: (1) sham-operated control, (2) HLI: subjected to unilateral femoral artery ligation, (3) HLI + chrysin: received 100 mg/kg, i.p. chrysin immediately after HLI, and (4) HLI + chrysin + rapamycin: received 6 mg/kg/day rapamycin i.p. for 5 days then subjected to HLI and dosed with 100 mg/kg chrysin, i.p. Rats were killed 18 h later and gastrocnemius muscles were collected and divided into parts for (1) immunohistochemistry detection of CD31 and CD105, (2) qRT-PCR analysis of eNOS and VEGFR2, (3) colorimetric analysis of NO, (4) ELISA estimation of TGF-β, VEGF, ATG5 and Beclin-1, and (5) Western blot analysis of p-PI3K, PI3K, p-Akt, Akt, p-mTOR, mTOR, and HIF-1α. Chrysin significantly enhanced microvessels growth in HLI muscles as indicated by increased CD31 and CD105 levels and decreased TGF-β. Chrysin's proangiogenic effect is potentially mediated by increased VEGF, VEGFR2 and activation of PI3K/AKT/mTOR pathway, which promoted eNOS and NO levels as it was reversed by the mTOR inhibitor, rapamycin. Chrysin also inhibited autophagy as it decreased ATG5 and Beclin-1. The current study shows that chrysin possesses a proangiogenic effect in HLI rats and might be useful in patients with PAD.

Topics: Angiogenesis Inducing Agents; Animals; Arterial Occlusive Diseases; Autophagy; Beclin-1; Flavonoids; Hindlimb; Ischemia; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Rats; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A

Stroke exacts a heavy toll on death and disability worldwide. In animal studies, cell transplant has shown a positive effect by inducing neurogenesis, angiogenesis, and modulating inflammation. Cell transplant therapy could provide researchers with new strategies for treating stroke. The mechanistic target of rapamycin is a central signaling pathway for coordination and control; the administration of rapamycin, a key modulator of this pathway, could be a new therapeutic approach in neurological disorders.. Adult rats were grouped into 5 main groups: control, sham, rapamycin receiving, Sertoli cell receiving, and rapamycin plus Sertoli cell receiving groups. Sertoli cells were taken from another rat tissue and injected into the right striatum region. After 5 days, ischemic induction was performed, and rapamycin injection (300 mg/kg) was performed 1 hour before surgery. After 24 hours, some regions of the brain, including the cortex, striatum, and piriform cortex-amygdala, were isolated for evaluation.. Our results showed that infarct volume, brain edema, and blood-brain barrier permeability assessments were significantly reduced in some areas of the brain in rats that received rapamycin plus Sertoli cells compared with results shown in the control group.. Pretreatment with Sertoli cell transplant plus rapamycin injection may enhance neural survival during ischemia through increased glial cell-derived neurotrophic factor and vascular endothelial growth factor, inhibiting the mechanistic target of rapamycin pathway and increasing autophagy performance.

Topics: Animals; Brain Ischemia; Cell Transplantation; Humans; Infarction, Middle Cerebral Artery; Ischemia; Male; Rats; Sertoli Cells; Sirolimus; Stroke; Treatment Outcome; Vascular Endothelial Growth Factor A

Topics: Aged; Angioplasty, Balloon; Cardiovascular Agents; Coated Materials, Biocompatible; Femoral Artery; Humans; Ischemia; Peripheral Arterial Disease; Sirolimus; Treatment Outcome; Vascular Access Devices

Rapamycin has antioxidant defense mechanisms and immune suppressive effects. To detect the short- and long-term effects of rapamycin on ischemic damage and apoptotic changes in torsion of rat testes, mature male albino Wistar rats (n = 48) were included in the study as control, sham, early torsion-detorsion (T/D), early rapamycin treatment, early rapamycin control, late T/D, late rapamycin treatment, and late rapamycin control. The right testis was rotated 720° in a clockwise direction during 4 h in operation groups. Rapamycin was administered orally three times: 30 min before detorsion and 24 and 48 h after detorsion. The animals were killed on the third day in early groups and on the tenth day in late groups after detorsion. Statistically significant differences among all groups were detected for SOD and TBARS, mean seminiferous tubule diameter (MSTD) and Cosentino's histologic score (CHS), caspase 3, bax, average number of apoptotic cells per tubule (ANPCT), and percentage of apoptotic tubule (PAT) values. ANPCT values ​​were 10% lower in the rapamycin treatment groups compared with the untreated T/D groups, and the PAT values ​​were also approximately 1.3 times lower. Although short-term usage of rapamycin may reduce to the tubular injury caused by I/R conversely to apoptosis in the testicular tissue after testicular torsion, rapamycin may have the potential to increase the long-term apoptosis with/without testicular torsion and a subsequent regression in fertility.

Topics: Animals; Apoptosis; Ischemia; Male; Malondialdehyde; Oxidative Stress; Protective Agents; Rats, Wistar; Sirolimus; Spermatic Cord Torsion; Superoxide Dismutase; Testis; Thiobarbituric Acid Reactive Substances

Endothelial progenitor cells (EPCs) are widely accepted to be applied in ischemic diseases. However, the therapeutic potency is largely impeded because of its inviability in these ischemic conditions. Autophagy is recognized to be vital in cell activity. Therefore, we explore the role and the mechanism of autophagy in ischemic EPCs.. We applied 7d-cultured bone marrow EPCs to investigate the autophagy status under the oxygen and glucose deprivation (OGD) conditions in vitro, mimicking the in-vivo harsh ischemia and anoxia microenvironment. We found increased EPC apoptosis, accompanied by an impaired autophagy activation. Intriguingly, mTOR inhibitor Rapamycin was incapable to reverse this damped autophagy and EPC damage. We further found that autophagy pathway downstream Vps34-Beclin1-Atg14 complex assembly and activity were impaired in OGD conditions, and an autophagy-inducing peptide Tat-Beclin1 largely recovered the impaired complex activity and attenuated OGD-stimulated EPC injury through restoring autophagy activation.. The present study discovered that autophagy activation is inhibited when EPCs located in the ischemia and anoxia conditions. Restoration of Vps34 complex activity obtains sufficient autophagy, thus promoting EPC survival, which will provide a potential target and advance our understanding of autophagy manipulation in stem cell transplantation.

Topics: Animals; Apoptosis; Autophagy; Beclin-1; Class III Phosphatidylinositol 3-Kinases; Endothelial Progenitor Cells; Glucose; Ischemia; Male; Mice, Inbred C57BL; Oxygen; Sirolimus; tat Gene Products, Human Immunodeficiency Virus

Penehyclidine hydrochloride (PHC) suppresses renal ischemia and reperfusion (I/R) injury (IRI); however, the underlying mechanism of action that achieves this function remains largely unknown. The present study aimed to investigate the potential role of autophagy in PHC‑induced suppression of renal IRI, as well as the involvement of cell proliferation and apoptosis. A rat IRI model and a cellular hypoxia/oxygenation (H/R) model were established; PHC, 3‑methyladenine (3‑MA) and rapamycin (Rapa) were administered to the IRI model rats prior to I/R induction and to H/R cells following reperfusion. Serum creatinine was measured using a biochemistry analyzer, whereas aspartate aminotransferase (ASAT) and alanine aminotransferase (ALAT) expression levels were detected using ELISA kits. Renal tissue injury was evaluated by histological examination. In addition, microtubule‑associated protein light chain 3B (LC3B) expression, autophagosome formation, cell proliferation and apoptosis were detected in the cellular H/R model. The results demonstrated that I/R induced renal injury in IRI model rats, upregulated serum creatinine, ALAT and ASAT expression levels, and increased autophagic processes. In contrast, pretreatment with PHC or Rapa significantly prevented these I/R‑induced changes, whereas the administration of 3‑MA enhanced I/R‑induced injuries through suppressing autophagy. PHC and Rapa increased LC3B and Beclin‑1 expression levels, but decreased sequestome 1 (p62) expression in the cellular H/R model, whereas 3‑MA prevented these PHC‑induced changes. PHC and Rapa promoted proliferation and autophagy in the cellular H/R model; these effects were accompanied by increased expression levels of LC3B and Beclin‑1, and reduced p62 expression levels, whereas these levels were inhibited by 3‑MA. Furthermore, PHC and Rapa inhibited apoptosis in the cellular H/R model through increasing Bcl‑2 expression levels, and suppressing Bax and caspase‑3 expression levels; the opposite effect was induced by 3‑MA. In conclusion, PHC suppressed renal IRI through the induction of autophagy, which in turn promoted proliferation and suppressed apoptosis in renal cells.

Topics: Adenine; Alanine Transaminase; Animals; Apoptosis; Aspartate Aminotransferases; Autophagy; Beclin-1; Caspase 3; Cell Proliferation; Disease Models, Animal; Ischemia; Kidney; Male; Quinuclidines; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Sirolimus

Topics: Animals; Diabetes Mellitus, Experimental; Ischemia; Mice; MicroRNAs; Myocardial Infarction; Sirolimus

Autophagy plays an important role in the pathogenesis of acute kidney injury (AKI). Although autophagy activation was shown to be associated with an increased lifespan and beneficial effects in various pathologies, the impact of autophagy activators, particularly, rapamycin and its analogues on AKI remains obscure. In our study, we explored the effects of rapamycin treatment in in vivo and in vitro models of ischemic and cisplatin-induced AKI. The impact of rapamycin on the kidney function after renal ischemia/reperfusion (I/R) or exposure to the nephrotoxic agent cisplatin was assessed by quantifying blood urea nitrogen and serum creatinine and evaluating the content of neutrophil gelatinase-associated lipocalin, a novel biomarker of AKI. In vitro experiments were performed on the primary culture of renal tubular cells (RTCs) that were subjected to oxygen-glucose deprivation (OGD) or incubated with cisplatin under various rapamycin treatment protocols. Cell viability and proliferation were estimated by the MTT assay and real-time cell analysis using an RTCA iCELLigence system. Although rapamycin inhibited mTOR (mammalian target of rapamycin) signaling, it failed to enhance the autophagy and to ameliorate the severity of AKI caused by ischemia or cisplatin-induced nephrotoxicity. Experiments with RTCs demonstrated that rapamycin exhibited the anti-proliferative effect in primary RTCs cultures but did not protect renal cells exposed to OGD or cisplatin. Our study revealed for the first time that the mTOR inhibitor rapamycin did not prevent AKI caused by renal I/R or cisplatin-induced nephrotoxicity and, therefore, cannot be considered as an ideal mimetic of the autophagy-associated nephroprotective mechanisms (e.g., those induced by caloric restriction), as it had been suggested earlier. The protective action of such approaches like caloric restriction might not be limited to mTOR inhibition and can proceed through more complex mechanisms involving alternative autophagy-related targets. Thus, the use of rapamycin and its analogues for the treatment of various AKI forms requires further studies in order to understand potential protective or adverse effects of these compounds in different contexts.

Topics: Acute Kidney Injury; Animals; Antineoplastic Agents; Cells, Cultured; Cisplatin; Glucose; Ischemia; Kidney Tubules; Male; Oxygen; Protective Agents; Rats; Sirolimus; TOR Serine-Threonine Kinases

Rapamycin is employed as an immunosuppressant following organ transplant and, in patients with hepatocellular carcinoma, to inhibit cancer cell regrowth following liver surgery. Preconditioning the liver with rapamycin to induce the expression of antioxidant enzymes is a potential strategy to reduce ischemia reperfusion (IR) injury. However, pre-treatment with rapamycin inhibits bile flow, especially following ischemia. The aim was to investigate the mechanisms involved in this inhibition. In a rat model of segmental hepatic ischemia and reperfusion, acute administration of rapamycin by intravenous injection did not inhibit the basal rate of bile flow. Pre-treatment of rats with rapamycin for 24 h by intraperitoneal injection inhibited the expression of mRNA encoding the sinusoidal influx transporters Ntcp, Oatp1 and 2 and the canalicular efflux transporter Bsep, and increased expression of canalicular Mrp2. Dose-response curves for the actions of rapamycin on the expression of Bsep and Ntcp in cultured rat hepatocytes were biphasic, and monophasic for effects on Oatp1. In cultured tumorigenic H4IIE liver cells, several bile acid transporters were not expressed, or were expressed at very low levels compared to hepatocytes. In H4IIE cells, rapamycin increased expression of Ntcp, Oatp1 and Mrp2, but decreased expression of Oatp2. It is concluded that the inhibition of bile flow recovery following ischemia observed in rapamycin-treated livers is principally due to inhibition of the expression of sinusoidal bile acid transporters. Moreover, in tumorigenic liver tissue the contribution of tumorigenic hepatocytes to total liver bile flow is likely to be small and is unlikely to be greatly affected by rapamycin.

Topics: Animals; Bile; Bile Ducts; Carcinoma, Hepatocellular; Carrier Proteins; Cell Line, Tumor; Cholestasis; Disease Models, Animal; Dose-Response Relationship, Drug; Hepatocytes; Humans; Immunosuppressive Agents; Ischemia; Liver; Liver Neoplasms; Liver Transplantation; Male; Membrane Glycoproteins; Rats; Rats, Sprague-Dawley; Rats, Zucker; Reperfusion Injury; Sirolimus; Transplantation Conditioning

Ischemia is one of the main causes of the high rate of absorption of transplanted autologous fat. Autophagy allows cells to survive by providing energy under starvation. Rapamycin has been found to play a role in promoting autophagy. In this study, we investigated whether rapamycin participates in the survival and adipogenesis of ischemia-challenged adipose-derived stem cells (ADSCs) by regulating autophagy.. Before the cells were exposed to oxygen-glucose deprivation (OGD), a simulated ischemic microenvironment, the level of autophagy was reduced or increased by lentiviral transfection with short hairpin RNA targeting microtubule-associated protein 1-light chain 3 gene (shRNA-LC3) or treatment with rapamycin, respectively. The level of autophagy was assessed by western blotting, transmission electron microscopythen the apoptosis ratio was determined through terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) and flow cytometry. Adipogenesis was further evaluated by oil red O staining and the expressions level of some specific proteins for adipocytes.. shRNA-LC3 and rapamycin treatment effectively decreased and improved the level of autophagy in cells with or without OGD challenge, respectively. In addition, autophagy inhibition increased the apoptosis rate and activated caspase-3 expression level in response to OGD, and these were markedly inhibited by rapamycin preconditioning. During adipogenesis, autophagy inhibition decreased not only oil droplet accumulation but also lipoprotein lipase (LPL) and peroxisome proliferator-activated receptor gamma (PPARγ) expression in cells with or without OGD challenge. However, autophagy promotion by rapamycin increased oil droplet accumulation and LPL and PPARγ expression.. Rapamycin may promote the survival and adipogenesis of ischemia-challenged ADSCs by upregulating autophagy.

Topics: Adipogenesis; Adipose Tissue; Apoptosis; Autophagy; Caspase 3; Cell Hypoxia; Cell Line; Cell Survival; Glucose; Humans; Ischemia; Microscopy, Electron, Transmission; Microtubule-Associated Proteins; PPAR gamma; RNA Interference; RNA-Binding Proteins; RNA, Small Interfering; Sirolimus; Stem Cells; Transfection

To explore the effect and mechanism of rapamycin and deferoxamin on wound healing after ischemia and hypoxia.. All rats survived to the end of the experiment, and wounds healed; the healing time of groups A, B, and D was significantly shorter than that of group C (. Defe-roxamin can promote the wound healing of rats after ischemia and hypoxia, and the effect of rapamycin is opposite. It may be related to the existence of mTOR and HIF-1 signaling pathway in chronic ischemia-hypoxia wound.. 探讨雷帕霉素及去铁敏对缺血缺氧创面愈合的影响及其作用机制。.. 各组大鼠均成活至实验完成，创面均愈合；其中 A、B、D 组创面愈合时间均较 C 组明显缩短（. 去铁敏可促进大鼠缺血缺氧创面愈合，而雷帕霉素作用相反；可能与慢性缺血缺氧创面中存在 mTOR 与 HIF-1 信号调节通路有关。.

Topics: Animals; Hypoxia; Hypoxia-Inducible Factor 1, alpha Subunit; Immunosuppressive Agents; Ischemia; Male; Rats; Rats, Sprague-Dawley; Sirolimus; Vascular Endothelial Growth Factor A; Wound Healing

The mammalian target of rapamycin (mTOR) is a key regulator of cell growth, autophagy, translation, and survival. Dysregulation of mTOR signaling is associated with cancer, diabetes, and autism. However, a role for mTOR signaling in neuronal death is not well delineated. Here we show that global ischemia triggers a transient increase in mTOR phosphorylation at S2448, whereas decreasing p-mTOR and functional activity in selectively vulnerable hippocampal CA1 neurons. The decrease in mTOR coincides with an increase in biochemical markers of autophagy, pS317-ULK-1, pS14-Beclin-1, and LC3-II, a decrease in the cargo adaptor p62, and an increase in autophagic flux, a functional readout of autophagy. This is significant in that autophagy, a catabolic process downstream of mTORC1, promotes the formation of autophagosomes that capture and target cytoplasmic components to lysosomes. Inhibitors of the lysosomal (but not proteasomal) pathway rescued the ischemia-induced decrease in mTOR, consistent with degradation of mTOR via the autophagy/lysosomal pathway. Administration of the mTORC1 inhibitor rapamycin or acute knockdown of mTOR promotes autophagy and attenuates ischemia-induced neuronal death, indicating an inverse causal relation between mTOR, autophagy, and neuronal death. Our findings identify a novel and previously unappreciated mechanism by which mTOR self-regulates its own levels in hippocampal neurons in a clinically relevant model of ischemic stroke.

Topics: Acetylcysteine; Adenine; AMP-Activated Protein Kinases; Animals; Autophagy; Autophagy-Related Protein-1 Homolog; Beclin-1; Cells, Cultured; Hippocampus; Ischemia; Leupeptins; Lysosomes; Male; Microtubule-Associated Proteins; Neurons; Phosphorylation; Rats; RNA Interference; Sirolimus; TOR Serine-Threonine Kinases

Autophagy enables cells to digest endogenous/exogenous waste products, thus potentially prolonging the cellular lifespan. Early endothelial progenitor cells (eEPCs) protect mice from ischemic acute kidney injury (AKI). The mid-term prognosis in AKI critically depends on vascular rarefication and interstitial fibrosis with the latter partly being induced by mesenchymal transdifferentiation of endothelial cells (EndoMT). This study aimed to determine the impact of eEPC preconditioning with different autophagy inducing agents [suberoylanilide hydroxamic acid (SAHA)/temsirolimus] in ischemic AKI.. Male C57/Bl6 N mice were subjected to bilateral renal ischemia (40 min). Animals were injected with either untreated, or SAHA- or temsirolimus-pretreated syngeneic murine eEPCs at the time of reperfusion. Mice were analyzed 48 h and 4 weeks later. In addition, cultured eEPCs were treated with transforming growth factor (TGF)-β ± SAHA, autophagy (perinuclear LC3-II), and stress-induced premature senescence (SIPS-senescence-associated β-galactosidase, SA-β-Gal), and were evaluated 96 h later.. Cultured eEPCs showed reduced perinuclear density of LC3-II + vesicles and elevated levels of SA-β-Gal after treatment with TGF-β alone, indicating impaired autophagy and aggravated SIPS. These effects were completely abrogated by SAHA. Systemic administration of either SAHA or tems pretreated eEPCs resulted in elevated intrarenal endothelial p62 at 48 h and 4 weeks, indicating stimulated endothelial autophagy. This effect was most pronounced after injection of SAHA-treated eEPCs. At 4 weeks endothelial expression of mesenchymal alpha-smooth muscle actin (αSMA) was reduced in animals receiving untreated and SAHA-pretreated cells. In addition, SAHA-treated cells reduced fibrosis at week 4. Tems in contrast aggravated EndoMT. Postischemic renal function declined after renal ischemia and remained unaffected in all experimental cell treatment groups.. In ischemic AKI, intrarenal endothelial autophagy may be stabilized by systemic administration of pharmacologically preconditioned eEPCs. Early EPCs can reduce postischemic EndoMT and fibrosis in the mid-term. Autophagy induction in eEPCs either increases or decreases the mesenchymal properties of intrarenal endothelial cells, depending on the substance being used. Thus, endothelial autophagy induction in ischemic AKI, mediated by eEPCs is not a renoprotective event per se.

Topics: Actins; Acute Kidney Injury; Animals; Autophagy; beta-Galactosidase; Cells, Cultured; Disease Models, Animal; Endothelial Progenitor Cells; Epithelial-Mesenchymal Transition; Fibrosis; Hydroxamic Acids; Ischemia; Kidney; Male; Mice, Inbred C57BL; Microtubule-Associated Proteins; Phenotype; Sirolimus; Time Factors; Transforming Growth Factor beta; Vorinostat

Topics: Aged; Aged, 80 and over; Drug-Eluting Stents; Female; Follow-Up Studies; Humans; Ischemia; Leg; Male; Middle Aged; Popliteal Artery; Radiography; Registries; Retrospective Studies; Sirolimus; Time Factors; Treatment Outcome

The protective potential of rapamycin has been reported in a few experimental models of brain ischemia, both in vivo and in vitro. Although the precise cellular processes underlying the neuroprotective effects of rapamycin in experimental models of stroke remain unknown, the current experimental data suggest that the mechanism of action of the drug may result from the mTOR-mediated autophagy induction. However, it is unclear whether the activation of autophagy acts as a pro-death or pro-survival factor in vascular endothelial cells in ischemic brain damage. It seems to be very important, since stroke affects not only neurons and astrocytes but also microvessels. In the present study, we used human umbilical vein endothelial cells (HUVEC) subjected to ischemia-simulating conditions (combined oxygen and glucose deprivation, OGD) for 6h to determine potential effect of rapamycin-induced autophagy on HUVEC damage. The drug at concentrations of 100 and 1000nM increased the expression of Beclin 1 and LC3-II together with a significant increase in the p62 degradation in ischemic HUVEC. Treatment with rapamycin in OGD significantly increased the cell viability, indicating that the drug exerts cytoprotective effect. The inhibition of Beclin 1 by siRNAs significantly attenuated the expression of autophagy-related proteins and reduced HUVEC viability following OGD and rapamycin treatment. Our findings demonstrated that toxicity of simulated ischemia conditions were enhanced in HUVEC when autophagy was blocked, and that rapamycin effectively prevented OGD-evoked damage by induction of protective autophagy via inhibition of the mTOR pathway.

Topics: Adaptor Proteins, Signal Transducing; Apoptosis Regulatory Proteins; Autophagy; Beclin-1; Cell Hypoxia; Cell Survival; Dose-Response Relationship, Drug; Gene Expression Regulation; Glucose; Human Umbilical Vein Endothelial Cells; Humans; Ischemia; Membrane Proteins; Microtubule-Associated Proteins; Neuroprotective Agents; Oxygen; RNA, Small Interfering; Sequestosome-1 Protein; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases

NKT cells play a protective role in ischemia reperfusion (IR) injury, of which the trafficking in the body and recruitment in injured organs can be influenced by immunosuppressive therapy. Therefore, we investigated the effects of rapamycin on kidneys exposed to IR injury in early stage and on trafficking of NKT cells in a murine model.. Balb/c mice were subjected to kidney 30 min ischemia followed by 24 h reperfusion. Rapamycin (2.5 ml/kg) was administered by gavage daily, starting 1 day before the operation. Renal function and histological changes were assessed. The proportion of NKT cells in peripheral blood, spleen and kidney was detected by flow cytometry. The chemokines and corresponding receptor involved in NKT cell trafficking were determined by RT-PCR and flow cytometry respectively.. Rapamycin significantly improved renal function and ameliorated histological injury. In rapamycin-treated group, the proportion of NKT cells in spleen was significantly decreased but increased in peripheral blood and kidney. In addition, the CXCR3+ NKT cell in the kidney increased remarkably in the rapamycin-treated group. The chemokines, CXCL9 and CXCL10, as the ligands of CXCR3, were also increased in the rapamycin-treated kidney.. Rapamycin may recruit NKT cells from spleen to the IR-induced kidney to ameliorate renal IR injury in the early stage.

Topics: Animals; Apoptosis; Chemotaxis, Leukocyte; Cytoprotection; Ischemia; Kidney; Kidney Function Tests; Killer Cells, Natural; Male; Mice; Mice, Inbred BALB C; Reperfusion Injury; Sirolimus

The aim of this study is to compare clinical outcomes for seven years, between sirolimus-eluting stent (SES) and bare metal stent (BMS). During the BMS and drug-eluting stent (DES) transition period (from April 2002 to April 2004), 434 consecutive patients with 482 lesions underwent percutaneous coronary intervention, using BMS or SES. Using propensity score matching, 186 patients with BMS and 166 patients with SES were selected. Seven year clinical outcomes of major adverse cardiac events (MACE), such as cardiac death, myocardial infarction (MI) and ischemia-driven target vessel revascularization (TVR), and angiographic definite stent thrombosis (ST) were compared. At one-year follow up, patients with SES showed significantly lower MACE (9.1% in BMS vs 3.0% in SES, P = 0.024). However, cumulative MACE for 7 yr was not significantly different between two groups (24.7% in BMS vs 17.4% in SES, P = 0.155). There was no significant difference in MI, TVR, death and ST. The TVR were gradually increased from 1 to 7 yr in SES, on the contrary to that of BMS. In conclusion, although SES showed better clinical outcomes in the early period after implantation, it did not show significant benefits in the long-term follow up, compared with that of BMS.

Topics: Aged; Angioplasty, Balloon, Coronary; Coronary Angiography; Coronary Stenosis; Databases, Factual; Drug-Eluting Stents; Female; Follow-Up Studies; Humans; Ischemia; Kaplan-Meier Estimate; Male; Middle Aged; Myocardial Infarction; Myocardial Revascularization; Registries; Sirolimus; Stents; Thrombosis

To investigate the pathogenesis of ischemic-type biliary lesions (ITBLs) in post-liver transplant patients and the possible therapeutic mechanisms of sirolimus.. The clinic data of 32 post-liver transplant patients with ITBLs from May 2004 to December 2010 was analyzed. There were including 25 male and 7 female patients with a median age of 46 years (ranging from 19 to 61 years). Patients were divided into those who received sirolimus (sirolimus group) and those who did not (control group). The expression of IL-2, FoxP3, and IL-10 in the portal area, liver function indexes, and bile duct injury score were assessed pre-ITBL, when ITBLs were identified, and after 6 months of sirolimus treatment.. Compared with pre-ITBL optical density (OD) values, there was a significantly increase in IL-2 OD(0.138 ± 0.050 in control group and 0.141 ± 0.052 in sirolimus group), but not FoxP3 and IL-10 OD in both groups at the time ITBLs were diagnosed. After 6 months of treatment, the IL-2, FoxP3, and IL-10 OD values in the control group were not different from those when ITBLs were diagnosed. There was a significant reduction in post-therapy IL-2 OD(0.107 ± 0.043, t = 2.087, P = 0.044), and a significant elevation in FoxP3(0.213 ± 0.039) and IL-10 OD(0.187 ± 0.048) in sirolimus group as compared with those when ITBLs were diagnosed(t = -3.822 and -4.350, both P < 0.01). There was a significant increase in serum levels of ALT, AST, total bilirubin, γ-glutamyl transpeptidase and ALP at the time ITBLs were diagnosed compared with pre-ITBL levels in both groups. After 6 months of treatment, the above indexes had not changed in the control group, but significantly improved in the sirolimus group, and the bile duct injury score in the sirolimus group had significantly decreased(4.4 ± 2.4, Z = -2.568, P = 0.010). The 1-year and 3-year graft survival rates in the control group were 6/13 and 5/13, respectively, and 17/19 and 13/19, respectively, in the sirolimus group (χ(2) = 7.166, P = 0.007; χ(2) = 5.398, P = 0.020, respectively).. Sirolimus can downregulate IL-2 expression and upregulate FoxP3 and IL-10 expression, thereby stimulating FoxP3+ Treg cells, suppressing immunopathological damage, and promoting epithelial repair in bile ducts.

Topics: Adult; Bile Duct Diseases; Female; Forkhead Transcription Factors; Gene Expression Regulation; Humans; Interleukin-10; Interleukin-2; Ischemia; Liver Transplantation; Male; Middle Aged; Postoperative Complications; Sirolimus; Young Adult

Poor cell survival severely limits the beneficial effects of stem cell therapy for peripheral arterial disease (PAD). This study was designed to investigate the role of mammalian target of rapamycin (mTOR) in the survival and therapeutic function of transplanted murine adipose-derived stromal cells (mADSCs) in a murine PAD model. mADSCs (1.0 × 10(7)) were isolated from dual-reporter firefly luciferase and enhanced green fluorescent protein-positive transgenic mice, intramuscularly implanted into the hind limb of C57BL/6 mice after femoral artery ligation/excision, and monitored using noninvasive bioluminescence imaging (BLI). Although engrafted mADSCs produced antiapoptotic/proangiogenic effects in vivo by modulating the inflammatory and angiogenic cytokine response involving the mTOR pathway, longitudinal BLI revealed progressive death of post-transplant mADSCs within ~4 weeks in the ischemic hind limb. Selectively targeting mTOR complex-1 (mTORC1) using low-dose rapamycin treatment with mADSCs attenuated proinflammatory cytokines (interleukin [IL]-1β and tumor necrosis factor-alpha [TNF-α]) expression and neutrophil/macrophage infiltration, which overtly promoted mADSCs viability and antiapoptotic/proangiogenic efficacy in vivo. However, targeting dual mTORC1/mTORC2 using PP242 or high-dose rapamycin caused IL-1β/TNF-α upregulation and anti-inflammatory IL-10, IL-6, and vascular endothelial growth factor/vascular endothelial growth factor receptor 2 downregulation, undermining the survival and antiapoptotic/proangiogenic action of mADSCs in vivo. Furthermore, low-dose rapamycin abrogated TNF-α secretion by mADSCs and rescued the cells from hypoxia/reoxygenation-induced death in vitro, while PP242 or high-dose rapamycin exerted proinflammatory effects and promoted cell death. In conclusion, mTORC1 and mTORC2 may differentially regulate inflammation and affect transplanted mADSCs' functional survival in ischemic hind limb. These findings uncover that mTOR may evolve into a promising candidate for mechanism-driven approaches to facilitate the translation of cell-based PAD therapy.

Topics: Adipocytes; Animals; Apoptosis; Cell Proliferation; Cell Survival; Disease Models, Animal; Down-Regulation; Femoral Artery; Green Fluorescent Proteins; Hindlimb; Inflammation; Interleukin-10; Interleukin-1beta; Interleukin-6; Ischemia; Luciferases, Firefly; Luminescent Measurements; Macrophages; Mechanistic Target of Rapamycin Complex 1; Mechanistic Target of Rapamycin Complex 2; Mice; Mice, Inbred C57BL; Mice, Transgenic; Multiprotein Complexes; Neovascularization, Pathologic; Neutrophils; Peripheral Arterial Disease; Proteins; Sirolimus; Stromal Cells; TOR Serine-Threonine Kinases; Tumor Necrosis Factor-alpha; Up-Regulation; Vascular Endothelial Growth Factor Receptor-2; Vascular Endothelial Growth Factors

Topics: Angioplasty; Arterial Occlusive Diseases; Cardiovascular Agents; Drug-Eluting Stents; Everolimus; Female; Humans; Ischemia; Male; Metals; Popliteal Artery; Sirolimus; Stents

To present the 5-year angiographic and clinical results of a retrospective registry assessing the performance of sirolimus-eluting stents (SES) in the treatment of infrapopliteal atherosclerotic disease.. From 2004 to 2009, 158 patients (95 men; mean age 71.9 years) with chronic lower limb ischemia (Rutherford categories 3-6) underwent primary SES placement in focal infrapopliteal lesions. The angiographic endpoint was patency, defined as freedom from in-stent stenosis (ISS) >50%. Clinical endpoints were death, amputation, and bypass surgery. Results were correlated with patient and lesion characteristics and cumulative outcomes were assessed with Kaplan-Meier analysis.. Technical success was achieved in all cases. The primary patency rates were 97.0% after 6 months, 87.0% after 12 months, and 83.8% at 60 months. In-stent stenosis was predominantly observed in the first year after stent placement. Female gender was associated with a higher rate of ISS. During clinical follow-up of 144 (91%) patients over a mean 31.1±20.3 months, there were 27 (18.8%) deaths, 4 (2.8%) amputations, and no bypass surgery. Clinical status improved in 92% of the patients with critical limb ischemia (CLI) and 77% of the patients suffering from claudication (p=0.022).. Treatment of focal infrapopliteal lesions with SES showed encouraging long-term angiographic results in this registry. Clinical improvement was evident, but more pronounced in CLI patients than in patients suffering from claudication. Further studies are needed to evaluate the potential clinical benefit of SES as compared to balloon angioplasty or bare metal stents in the treatment of infrapopliteal lesions.

Topics: Aged; Aged, 80 and over; Amputation, Surgical; Angioplasty, Balloon; Atherosclerosis; Cardiovascular Agents; Chi-Square Distribution; Chronic Disease; Constriction, Pathologic; Drug-Eluting Stents; Female; Germany; Humans; Ischemia; Kaplan-Meier Estimate; Lower Extremity; Male; Middle Aged; Popliteal Artery; Proportional Hazards Models; Prosthesis Design; Radiography; Registries; Retrospective Studies; Risk Assessment; Risk Factors; Sirolimus; Time Factors; Treatment Outcome; Vascular Patency; Vascular Surgical Procedures

Topics: Angioplasty, Balloon; Atherosclerosis; Cardiovascular Agents; Drug-Eluting Stents; Female; Humans; Ischemia; Lower Extremity; Male; Popliteal Artery; Sirolimus

To report the long-term outcomes of a single-center prospective study investigating primary placement of everolimus-eluting metal stents for recanalization of long infrapopliteal lesions compared to a matched historical control group treated with plain balloon angioplasty and provisional placement of bare metal stents in a bailout manner.. The study included 81 patients (63 men; mean age 71 years, range 45-85) suffering from critical limb ischemia (CLI) and angiographically proven long-segment (at least 1 lesion >4.5 cm) de novo infrapopliteal artery disease who underwent below-the-knee revascularization with either primary placement of everolimus-eluting stents (n = 47, 51 limbs, 102 lesions) or angioplasty and bailout bare metal stenting (n = 34, 36 limbs, 72 lesions). Clinical and angiographic follow-up was collected at regular time intervals. Primary clinical and angiographic endpoints included patient survival, major amputation-free survival, angiographic primary patency, angiographic binary restenosis (>50%), and overall event-free survival. Results were stratified according to endovascular treatment received. Multivariable Cox proportional hazards regression analysis was applied to adjust for confounding factors of heterogeneity.. Baseline demographics were well matched. No significant differences were identified between the 2 groups with regard to overall 3-year patient survival (82.2% versus 65.7%; p = 0.90) and amputation-free survival (77.1% versus 86.9%; p = 0.20). Up to 3 years, lesions fully covered with everolimus-eluting stents were associated with significantly higher primary patency [hazard ratio (HR) 7.98, 95% CI 3.69 to 17.25, p < 0.0001], reduced binary restenosis (HR 2.94, 95% CI 1.74 to 4.99, p < 0.0001), and improved overall event-free survival (HR 2.19, 95% CI 1.16 to 4.13, p = 0.015) versus the matched historical control group.. Primary infrapopliteal everolimus-eluting stenting for CLI treatment significantly inhibits restenosis and improves long-term angiographic patency and overall patient event-free survival compared to balloon angioplasty and bailout bare metal stenting.

Topics: Aged; Aged, 80 and over; Amputation, Surgical; Angioplasty, Balloon; Arterial Occlusive Diseases; Cardiovascular Agents; Constriction, Pathologic; Critical Illness; Disease-Free Survival; Drug-Eluting Stents; Everolimus; Female; Greece; Humans; Ischemia; Kaplan-Meier Estimate; Lower Extremity; Male; Metals; Middle Aged; Popliteal Artery; Proportional Hazards Models; Prospective Studies; Radiography; Risk Assessment; Risk Factors; Sirolimus; Stents; Time Factors; Treatment Outcome; Vascular Patency

The protective potential of immunosuppressants has been reported in many experimental models of ischemia both in vivo and in vitro, suggesting a novel therapeutic application of these drugs. Because high-mobility group box 1 (HMGB1) protein has recently been reported to be involved in ischemic brain injury, the purpose of the present study was to determine whether treatment with immunosuppressants could decrease the expression and release of HMGB1 in astrocytes exposed to simulated ischemic conditions (combined oxygen-glucose deprivation, OGD). We also investigated whether immunosuppressive drugs could attenuate necrosis in astrocyte cultures exposed to OGD. Finally, we studied the influence of immunosuppressants on the expression of NFκB, inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2). Cells were treated with cyclosporine A, FK506 and rapamycin (all drugs at concentrations of 0.1, 1 and 10 μM). Our study provides evidence that immunosuppressants decrease the expression and release of HMGB1 in ischemic astrocytes. Our data suggest that HMGB1 release may be partly an active process triggered by oxidative stress because the antioxidant N-acetylcysteine (NAC) clearly attenuated HMGB1 expression and release. Furthermore, we show that the immunosuppressants, at the same concentrations that significantly suppressed HMGB1 expression and release, were also able to prevent the necrosis of ischemic astrocytes and inhibit the expression of inflammatory mediators (NFκ, iNOS and COX-2). These results provide further information about the cytoprotective mechanisms of immunosuppressants on ischemic astrocytes, especially in relation to the pathophysiology of ischemic brain injury. It appears that the protective effects of immunosuppressants can be mediated in part by the suppressing the expression and release of HMGB1 in astrocytes, which leads to the attenuation of ischemia-induced necrosis and neuroinflammation.

Topics: Animals; Astrocytes; Cell Hypoxia; Cells, Cultured; Cyclosporine; Dose-Response Relationship, Drug; Glucose; HMGB1 Protein; Immunosuppressive Agents; Inflammation; Inflammation Mediators; Ischemia; Necrosis; Oxidative Stress; Rats; Rats, Wistar; Sirolimus; Tacrolimus

Midterm technical and clinical evaluation of stent angioplasty with drug-eluting stents in infrapopliteal lesions in patients with critical limb ischemia (CLI).. Percutaneous stent angioplasty was performed in 128 limbs in 114 patients presenting with 320 vascular lesions. Lesions with up to 6 cm in length and at least one patent vessel below the obstruction were treated; 341 drug-eluting Cypher(R) stents (diameter of 2.5-3.5 mm; length of 18-33 mm) were implanted. Follow-up examinations were performed up to 18 months postinterventionally using clinical examination, ankle-brachial index (ABI) calculation, and color coded Duplex sonography. Patency rates were calculated on the basis of the Kaplan-Meier life-table analysis.. Technical success was achieved in 99.06%. Minor complications (hematoma, distal emboli, and vessel dissection) were documented in 8.77% of the patients. The 6, 12, and 18 months primary patency rate as controlled by Duplex sonography was 89.8, 84.2 and 83.3%, respectively; 77.6% of the lesions healed postinterventionally. The cumulative limb salvage rate was 95.6%.. Drug-eluting stent (DES) angioplasty in infrapopliteal arteries is a safe and effective technique for the treatment of patients with CLI. The use of a DES results in favorable technical and clinical outcome in the midterm follow-up.

Topics: Adult; Aged; Aged, 80 and over; Angioplasty, Balloon; Ankle Brachial Index; Arterial Occlusive Diseases; Cardiovascular Agents; Critical Illness; Drug-Eluting Stents; Female; Germany; Humans; Ischemia; Kaplan-Meier Estimate; Limb Salvage; Lower Extremity; Male; Middle Aged; Prospective Studies; Severity of Illness Index; Sirolimus; Time Factors; Treatment Outcome; Ultrasonography, Doppler, Color; Vascular Patency

This study attempted to establish whether a calcineurin inhibitor (CNI)-free immunosuppressant regimen based on sirolimus (SRL) is associated with a preservation of conduit arteries endothelial function in kidney recipients or not. Twenty-nine kidney recipients were randomized to receive since transplantation SRL (n=15) or cyclosporin A (CsA, n=14) associated with mycophenolate mofetil (MMF) and steroids (6months) in a parallel prospective study. Systolic, diastolic blood pressures, glomerular filtration rate (GFR) and radial artery flow-mediated dilatation (FMD) induced by postischaemic hyperaemia were assessed in a blind manner at one (M1) and 7months (M7) after transplantation. Endothelium-independent dilatation was assessed by glyceryl trinitrate spray. There was no difference between the groups for all vascular parameters at M1. At M7, systolic blood pressure was lower (SRL: 119±3 vs. CsA: 138±4mmHg, P<0.05) and FMD was higher in SRL compared with CsA (SRL: 13.1±0.9 vs. CsA: 9.9±0.9%, P<0.05) without any difference for hyperaemia, endothelium-independent dilatation and GFR (SRL: 66.7±1.05 vs. CsA: 67.5±1.22ml/min). Our results demonstrate that a CNI-free regimen based on SRL and MMF prevents conduit artery endothelial dysfunction compared with CsA and MMF in kidney recipients suggesting a beneficial arterial wall effect that may also contribute to the decrease in systolic blood pressure.

Topics: Adult; Arteries; Blood Pressure; Cyclosporine; Endothelium, Vascular; Female; Glomerular Filtration Rate; Humans; Immunosuppressive Agents; Ischemia; Kidney; Kidney Transplantation; Male; Middle Aged; Prospective Studies; Sirolimus; Time Factors

To report 12-month outcomes following application of sirolimus-eluting stents (SES) in infrapopliteal arteries in patients with chronic limb ischemia.. A prospective single-center study was conducted involving 146 consecutive patients (102 men; mean age 73+/-9 years) with Rutherford-Becker categories 2 to 5 lower limb ischemia who underwent SES placement. The average degree of stenosis at baseline was 86%+/-5%; there were 44 (30%) occlusions. The main study endpoint was the 1-year primary patency rate, defined as freedom from in-stent restenosis (luminal narrowing > or =70%) detected with angiography or, if appropriate, with duplex ultrasound. Secondary endpoints included the 6-month primary patency rate, secondary patency rate, ankle-brachial index (ABI), and changes in the Rutherford-Becker classification.. Fifteen (10%) patients were lost to follow-up, and 27 (18%) patients died during the follow-up period, leaving 104 patients undergoing the 6- and 12-month follow-up examinations. After 6 months and 1 year, the primary patency rates were 88.5% and 83.7%, respectively. The mean ABI increased from 0.6+/-0.4 at baseline to 0.8+/-0.2 after 6 months and remained significantly improved during 1-year follow-up (p<0.0001). The mean Rutherford-Becker classification decreased from 3.3+/-0.8 at baseline to 0.9+/-1.1 (p<0.0001) after 1 year.. Treatment of infrapopliteal arteries with SES yields encouraging long-term results that compare favorably with previously published data on bare metal stents or plain balloon angioplasty.

Topics: Aged; Aged, 80 and over; Angioplasty, Balloon; Ankle Brachial Index; Arterial Occlusive Diseases; Cardiovascular Agents; Chronic Disease; Constriction, Pathologic; Disease-Free Survival; Drug-Eluting Stents; Female; Germany; Humans; Ischemia; Kaplan-Meier Estimate; Logistic Models; Lower Extremity; Male; Middle Aged; Odds Ratio; Popliteal Artery; Prospective Studies; Prosthesis Design; Radiography; Recurrence; Registries; Risk Assessment; Risk Factors; Severity of Illness Index; Sirolimus; Time Factors; Treatment Outcome; Ultrasonography, Doppler, Duplex; Vascular Patency

Topics: Angioplasty, Balloon; Arterial Occlusive Diseases; Cardiovascular Agents; Chronic Disease; Constriction, Pathologic; Drug-Eluting Stents; Humans; Ischemia; Limb Salvage; Lower Extremity; Popliteal Artery; Prosthesis Design; Recurrence; Risk Assessment; Risk Factors; Severity of Illness Index; Sirolimus; Time Factors; Treatment Outcome; Vascular Patency

Obesity and age are important risk factors for cardiovascular disease. However, the signaling mechanism linking obesity with age-related vascular senescence is unknown. Here we show that mice fed a high-fat diet show increased vascular senescence and vascular dysfunction compared to mice fed standard chow and are more prone to peripheral and cerebral ischemia. All of these changes involve long-term activation of the protein kinase Akt. In contrast, mice with diet-induced obesity that lack Akt1 are resistant to vascular senescence. Rapamycin treatment of diet-induced obese mice or of transgenic mice with long-term activation of endothelial Akt inhibits activation of mammalian target of rapamycin (mTOR)-rictor complex 2 and Akt, prevents vascular senescence without altering body weight, and reduces the severity of limb necrosis and ischemic stroke. These findings indicate that long-term activation of Akt-mTOR signaling links diet-induced obesity with vascular senescence and cardiovascular disease.

Topics: Animals; Cardiovascular Diseases; Carrier Proteins; Cellular Senescence; Disease Susceptibility; Eating; Enzyme Activation; Ischemia; Mice; Mice, Transgenic; Obesity; Phosphotransferases (Alcohol Group Acceptor); Proto-Oncogene Proteins c-akt; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases

No data are currently available on the role of oral sirolimus in the prevention of recurrent stenosis in the periphery. We report the effects of oral sirolimus in the prevention of recurrent infrainguinal obstructions in patients with complex peripheral arterial disease. Three patients with ischemic rest pain of the lower limbs and repeated short-term need for surgical and/or endovascular revascularization: 9 times within 12 months, 7 times within 15 months, 11 times within 26 months, respectively. Oral sirolimus on a case by case basis, resulted in less frequent restenosis and longer intervention-free intervals: three re-interventions within 37 months in the first patient, one balloon angioplasty within 17 months in the second, and three re-interventions within 21 months in the third patient, respectively. Side effects, in particular dyspepsia and diarrhoea, were mild and tolerable. To our knowledge, this is the first report to show that oral sirolimus was successfully administered in patients with recurrent excessive neointimal proliferation after revascularization of peripheral arterial lesions lowering the necessity of re-intervention and hence prolonging intervention-free intervals.

Topics: Administration, Oral; Aged; Angioplasty, Balloon; Cardiovascular Agents; Constriction, Pathologic; Female; Humans; Ischemia; Lower Extremity; Male; Middle Aged; Peripheral Vascular Diseases; Reoperation; Saphenous Vein; Secondary Prevention; Sirolimus; Thrombectomy; Treatment Failure; Vascular Surgical Procedures

Treatment of in-stent restenosis (ISR) is a challenging clinical problem. Recent studies have verified the safety and efficacy of first-generation DES for the treatment of ISR. The safety and effectiveness of new-generation drug-eluting stents (nDES) for ISR has not been previously investigated. The aim of the present study was to prospectively evaluate the clinical outcomes after treatment with nDES implantation in patients with bare metal stent (BMS) ISR.. Consecutive patients with ISR after BMS implantation were included. Primary end-point was a major adverse cardiac event (MACE), defined as death, myocardial infarction (MI), or target vessel revascularization (TVR). The incidence of stent thrombosis was also evaluated.. A total of 46 consecutive patients were enrolled for the treatment of ISR, 23 patients from ZES and 23 from EES group. There were two (8.7%) cases of TVR in ZES cohort due to proliferative ISR at 6 and 7 months after DES implantation, and none in EES. One (4.3%) patient underwent percutaneous coronary intervention and the other (4.3%) was treated surgically. Neither acute nor subacute thrombosis was observed during the 13.3+/-6.3 months follow-up period. In all other patients, stress test was negative for ischemia at 6 months.. In this prospective study, we showed that direct nDES implantation is highly effective for ISR and seems to be a promising management for the treatment of ISR.

Topics: Aged; Coronary Restenosis; Drug-Eluting Stents; Everolimus; Exercise Test; Female; Humans; Immunosuppressive Agents; Ischemia; Male; Middle Aged; Outcome and Process Assessment, Health Care; Prospective Studies; Sirolimus; Stents; Treatment Outcome

Loss of the promyelocytic leukaemia (PML) tumour suppressor has been observed in several human cancers. The tumour-suppressive function of PML has been attributed to its ability to induce growth arrest, cellular senescence and apoptosis. Here we identify PML as a critical inhibitor of neoangiogenesis (the formation of new blood vessels) in vivo, in both ischaemic and neoplastic conditions, through the control of protein translation. We demonstrate that in hypoxic conditions PML acts as a negative regulator of the synthesis rate of hypoxia-inducible factor 1alpha (HIF-1alpha) by repressing mammalian target of rapamycin (mTOR). PML physically interacts with mTOR and negatively regulates its association with the small GTPase Rheb by favouring mTOR nuclear accumulation. Notably, Pml-/- cells and tumours display higher sensitivity both in vitro and in vivo to growth inhibition by rapamycin, and lack of PML inversely correlates with phosphorylation of ribosomal protein S6 and tumour angiogenesis in mouse and human tumours. Thus, our findings identify PML as a novel suppressor of mTOR and neoangiogenesis.

Topics: Animals; Cell Hypoxia; Cell Line, Tumor; Cell Nucleus; Fibroblasts; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Ischemia; Mice; Monomeric GTP-Binding Proteins; Neoplasm Proteins; Neoplasms; Neovascularization, Pathologic; Neuropeptides; Nuclear Proteins; Phosphorylation; Promyelocytic Leukemia Protein; Protein Binding; Protein Biosynthesis; Protein Kinases; Ras Homolog Enriched in Brain Protein; Repressor Proteins; Ribosomal Protein S6; Sirolimus; TOR Serine-Threonine Kinases; Transcription Factors; Tumor Suppressor Proteins

To assess the safety and efficacy of sirolimus-eluting stents (SESs) in the treatment of severe intermittent claudication and critical limb ischaemia with "below-the-knee" lesions, unsuitable for surgery.. Limited published evidence suggests that drug-eluting stents may offer significant improvements in the treatment of infrapopliteal lesions.. Thirty consecutive patients with either severe intermittent claudication or critical limb ischemia (CLI), category 3-6 of Rutherford classification, and multivessel disease of infrapopliteal arteries (> or = 2 vessels) were treated with SES. Sixty-two arteries were treated with 106 SES. Mean age was 73.9 years, 77% of patients were male and 36% diabetic. The primary endpoint was clinical improvement and healing of ulcers at short term (1 month) and mid term (7.7 months). The secondary endpoint was primary vessel patency rate (angiographic or duplex assessment). All patients received clopidogrel (75 mg daily) or ticlopidine (150 mg daily) for 2 months or longer.. Angiographic and procedural success was achieved in all patients. At 7 months (7.7 +/- 5.8), it was necessary to amputate 1 toe in one patient and 1 mid-foot in another. Limb salvage was obtained in 100% of patients. Other events were: two cardiac deaths unrelated to CLI, one stroke with hemiparesia, one initial reperfusion syndrome, one contralateral CLI, and three recurrent homolateral claudication cases. All surviving patients had a mid-term clinical improvement with 97% of primary patency (56 patent arteries on 58 arteries).. Treatment of "below-the-knee" lesions with SES may provide an alternative treatment for patients with CLI.

Topics: Adult; Aged; Aged, 80 and over; Blood Vessel Prosthesis Implantation; Cardiovascular Agents; Coated Materials, Biocompatible; Equipment Safety; Female; Follow-Up Studies; Humans; Intermittent Claudication; Ischemia; Kaplan-Meier Estimate; Leg; Male; Middle Aged; Peripheral Vascular Diseases; Platelet Aggregation Inhibitors; Popliteal Artery; Prospective Studies; Research Design; Severity of Illness Index; Sirolimus; Stents; Time Factors; Treatment Outcome; Vascular Patency

To present a patient in whom severe external carotid artery (ECA) stenosis causing ocular ischemia was treated with a drug-eluting stent.. A 55-year-old woman with severe, diffuse atherosclerosis presented with impaired left ocular perfusion and amaurosis fugax. Duplex ultrasonography and angiography documented bilateral occlusion at the origin of the internal carotid arteries, bilateral subtotal ECA stenoses, and subtotal distal left common carotid artery (CCA) restenosis following endarterectomy. Percutaneous revascularization of the left ECA and CCA stenoses was performed using a short coronary balloon-expandable sirolimus-eluting stent and a self-expanding nitinol stent, respectively. The procedure was uneventful, and the ocular symptoms resolved. At 6 months, the patient remained asymptomatic, with angiographically patent stents.. Drug-eluting stenting may be a novel option to treat symptomatic ECA stenosis.

Topics: Alloys; Amaurosis Fugax; Angiography, Digital Subtraction; Blood Vessel Prosthesis Implantation; Carotid Artery, Common; Carotid Stenosis; Coated Materials, Biocompatible; Endarterectomy, Carotid; Eye; Female; Humans; Immunosuppressive Agents; Ischemia; Middle Aged; Postoperative Complications; Reoperation; Sirolimus; Stents; Vascular Patency

Microvascular thrombosis is a prominent feature in cardiac delayed xenograft rejection (DXR). We investigated the impact of warfarin or low-molecular-weight heparin (LMWH) anti-coagulation on xenograft function using a heterotopic pig-to-primate model. Donor hearts were from CD46 transgenic pigs and baboon immunosuppression included tacrolimus, sirolimus, anti-CD20 and TPC, an alpha-galactosyl-polyethylene glycol conjugate. Three groups of animals were studied. Group 1 (n = 9) was treated with warfarin, Group 2 (n = 13) with LMWH and Group 3, received no anti-coagulant drugs. The median duration of xenograft function was 20 days (range 3-62 days), 18 days (range 5-109 days) and 15 days (range 4-53 days) in Groups 1 to 3 respectively. Anti-coagulation achieved the targeted international normalized prothrombin ratio (INR) and anti-factor Xa levels consistent with effective in vivo therapy yet, no significant impact on median xenograft function was observed. At rejection, a similar histology of thrombosis and ischemia was apparent in each group and the levels of fibrin deposition and platelet thrombi in rejected tissue was the same. Anti-coagulation with warfarin or LMWH did not have a significant impact on the onset of DXR and microvascular thrombosis. However, a role for specific anti-coagulant strategies to achieve long-term xenograft function cannot be excluded.

Topics: Animals; Animals, Genetically Modified; Anticoagulants; Antigens, CD; Factor Xa; Heart Transplantation; Heparin, Low-Molecular-Weight; Immunoglobulin G; Immunoglobulin M; Immunosuppressive Agents; International Normalized Ratio; Ischemia; Membrane Cofactor Protein; Membrane Glycoproteins; Microcirculation; Myocardium; Papio; Primates; Prothrombin; Sirolimus; Swine; Tacrolimus; Thrombosis; Time Factors; Transplantation, Heterologous; Treatment Outcome; Vitamin K; Warfarin

To report the 6-month angiographic results from a prospective single-center study investigating the efficacy and outcome of sirolimus-eluting stents used for bailout after infrapopliteal revascularization of patients with critical limb ischemia (CLI).. Twenty-nine patients (21 men; mean age 68.7 years) underwent infrapopliteal revascularization with bare metal stents (group B) implanted for bailout in 65 lesions (38 stenoses and 27 occlusions) in 40 infrapopliteal arteries. Another 29 patients (21 men; mean age 68.8 years) underwent infrapopliteal bailout stenting with sirolimus-eluting stents (group S) in 66 lesions (46 stenoses and 20 occlusions) in 41 vessels. Preliminary 6-month angiographic and clinical results were analyzed.. Hyperlipidemia and symptomatic cardiac and carotid diseases were more pronounced in group S (p<0.05). Technical success was 96.6% (28/29 limbs) in group B versus 100.0% in group S (p=0.16). Six-month primary patency was 68.1% in group B versus 92.0% in group S (p<0.002). Binary in-stent and in-segment restenosis rates were 55.3% and 66.0%, respectively, in patients with bare stents versus 4.0% and 32.0%, respectively, in patients treated with the sirolimus-eluting stents (both p<0.001). The target lesion re-intervention rate at 6 months was 17.0% in group B versus 4.0% in group S (p=0.02). Limb salvage was 100% in both groups. Six-month mortality and minor amputation rates were 6.9% and 17.2%, respectively, in group B versus 10.3% and 3.4%, respectively, in group S (p=0.32 and p=0.04, respectively).. Sirolimus-eluting stents seem to restrict neointimal hyperplasia in the infrapopliteal vascular bed.

Topics: Aged; Angiography; Arterial Occlusive Diseases; Female; Graft Occlusion, Vascular; Humans; Immunosuppressive Agents; Ischemia; Leg; Male; Popliteal Artery; Prospective Studies; Recurrence; Sirolimus; Statistics, Nonparametric; Stents; Treatment Outcome

Discovery of the common and ubiquitous molecular targets for the disruption of angiogenesis, that are independent of the characteristics of malignant tumors, is desired to develop the more effective antitumor drugs. In this study, we propose that the platelet-derived growth factor receptor-alpha (PDGFRalpha)-p70S6K signal transduction pathway in mesenchymal cells, which is required for functional angiogenesis induced by fibroblast growth factor-2, is the potent candidate. Using murine limb ischemia as a tumor-free assay system, we demonstrated that p70S6K inhibitor rapamycin (RAPA) targets mesenchymal cells to shut down the sustained expression of vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF), via silencing of the PDGFRalpha-p70S6K pathway. Irrespective of the varied expression profiles of angiogenic factors in each tumor tested, RAPA constantly led the tumors to dormancy and severe ischemia in the time course, even associated with upregulated expression of VEGF from tumors. Because RAPA showed only a minimal effect to hypoxia-related expression of VEGF in culture, these results suggest that RAPA targets the host-vasculature rather than tumor itself in vivo. Thus, our current study indicates that the PDGFRalpha-p70S6K pathway is an essential regulator for FGF-2-mediated therapeutic neovascularization, as well as for the host-derived vasculature but not tumors during tumor angiogenesis, via controlling continuity of expression of multiple angiogenic growth factors.

Topics: Animals; Carcinoma, Squamous Cell; Cell Hypoxia; Epidermal Growth Factor; Fibroblast Growth Factor 2; Gene Expression Regulation; Hepatocyte Growth Factor; Hindlimb; Humans; Ischemia; Liver Neoplasms, Experimental; Male; Mesoderm; Mice; Mice, Inbred C57BL; Mice, Nude; Mouth Neoplasms; Neoplasm Proteins; Neovascularization, Pathologic; Neovascularization, Physiologic; Platelet-Derived Growth Factor; Receptor, Platelet-Derived Growth Factor alpha; Ribosomal Protein S6 Kinases, 70-kDa; Signal Transduction; Sirolimus; Stromal Cells

To determine the effect of cyclosporine and rapamycin administration on renal function after ischemia/reperfusion injury (I/R). Cyclosporine A has known nephrotoxic effects. Thus, cyclosporine therapy subsequent to I/R injury may further exacerbate graft dysfunction. Rapamycin is a newer agent that suppresses the immune system by a different mechanism.. Male Wistar rats (250 g) were anesthetized, and the suprarenal aorta was clamped for 40 minutes. The right kidney was removed. After recovery, the rats were divided into four groups: group 1, controls, no ischemia and no treatment (n = 10); group 2, ischemia with no treatment (n = 8); group 3, ischemia plus rapamycin (0.17 mg/kg/day gavage, n = 8); and group 4, ischemia plus cyclosporine A (30 mg/kg/day intraperitoneally, n = 9). The glomerular filtration rate was measured 5 to 7 days after I/R injury using urinary iohexol clearance. Data are expressed as the mean +/- SEM, and intergroup comparisons were made using one-way analysis of variance.. The mean GFR value for the controls (no ischemia, no treatment) was 1.23 +/- 0.08 mL/min; for group 2 (ischemia, no treatment), it was 1.05 +/- 0.10 mL/min; for group 3 (ischemia plus rapamycin) 1.06 +/- 0.14 mL/min; and for group 4 (ischemia plus cyclosporine A) 0.44 +/- 0.06 mL/min (P <0.05 versus the other three groups). The mean arterial pressure was significantly lower in the ischemic rats treated with cyclosporine A (P <0.05 versus the other three groups).. After I/R injury, rapamycin may preserve renal function compared with cyclosporine treatment, because it does not have a direct vasoconstrictor effect on the renal microcirculation.

Topics: Animals; Calcineurin; Cyclosporine; Glomerular Filtration Rate; Immunosuppressive Agents; Ischemia; Kidney; Kidney Diseases; Kidney Transplantation; Male; Nephrectomy; Postoperative Complications; Rats; Rats, Wistar; Reperfusion Injury; Sirolimus; Tissue and Organ Procurement

Ischaemia was obtained in vitro by subjecting nerve-growth-factor-differentiated PC12 cells to glucose deprivation plus anoxia. During ischaemia the rate of protein synthesis was significantly inhibited, and eIF4E-binding protein (4E-BP1) and eukaryotic initiation factor 4E (eIF4E) were significantly dephosphorylated in parallel. In addition, ischaemia induced an enhancement of the association of 4E-BP1 to eIF4E, which in turn decreased eIF4F formation, whereas no degradation of initiation factor 4G was observed. The treatment of PC12 cells with the specific p38 mitogen-activated protein kinase inhibitor SB203580 induced eIF4E dephosphorylation but did not cause any effect on protein synthesis rate. Rapamycin, the inhibitor of mammalian target of rapamycin ('mTOR'), but not PD98059, the inhibitor of extracellular signal-regulated protein kinases ('ERK1/2'), induced similar effects on 4E-BP1 phosphorylation to ischaemia; nevertheless, 4E-BP1-eIF4E complex levels were higher in ischaemia than in rapamycin-treated cells. In addition, both protein synthesis rate and eIF4F formation were lower in ischaemic cells than in rapamycin-treated cells.

Topics: Animals; Antibiotics, Antineoplastic; Carrier Proteins; Cell Survival; Enzyme Inhibitors; Eukaryotic Initiation Factor-4E; Eukaryotic Initiation Factor-4G; Flavonoids; Glucose; Hypoxia; Imidazoles; Intracellular Signaling Peptides and Proteins; Ischemia; Mitogen-Activated Protein Kinases; p38 Mitogen-Activated Protein Kinases; PC12 Cells; Peptide Initiation Factors; Phosphoproteins; Phosphorylation; Protein Binding; Protein Synthesis Inhibitors; Pyridines; Rats; Sirolimus; Time Factors

Topics: Animals; Aorta, Abdominal; Arteriosclerosis; Everolimus; Immunosuppressive Agents; Ischemia; Male; Polyenes; Postoperative Complications; Rats; Rats, Inbred F344; Sirolimus; Transplantation, Isogeneic; Tunica Intima

Gut ischemia has been implicated in the pathogenesis of necrotizing enterocolitis. Cyclosporine A and rapamycin, both potent novel immunosuppressants which act on signal transduction pathways in CD4+ T-cells, could potentially modulate immune/inflammatory cellular reactions involved in tissue ischemia/reperfusion injury. We hypothesized that cyclosporine A and rapamycin would preserve mucosal cell function and attenuate inflammatory T-cell-mediated cellular changes associated with small bowel ischemic injury. Forty Sprague-Dawley rats underwent 60 min of gut ischemia by vascular occlusion of the superior mesenteric vessels. Animals were randomized to four groups (n = 10): cyclosporine A (CSA, 5 mg/kg/day SQ), rapamycin (RAP, 2 mg/kg/day SQ), cyclosporine A and rapamycin (C&R), and vehicle given to controls (CON). Following 1 hr of reperfusion, small bowel was harvested for xanthine oxidase (XO, units/mg protein) and maltase (MALT, mM substrate degraded/min/g protein) assays. Blood was obtained from the portal vein for tumor necrosis factor-alpha (TNF-alpha, pg/ml) assay. The results of the study are presented below (mean +/- SEM, *, P < 0.05 versus controls). (Table in text) The results indicate that cyclosporine and rapamycin each play a significant role in attenuating ischemia/reperfusion injury in the gut. These data suggest that there are cytoprotective and anti-inflammatory mechanisms of these drugs independent of T-cell signal transduction that provide some protective effect in small bowel ischemia. Furthermore, T-cell-mediated immune mechanisms may not be associated with the adverse effects of small bowel ischemia/reperfusion injury. Additional investigation will be necessary in order to define the role of T-cell-mediated immune injury in the gut and how this relates to the beneficial effect of immunosuppression in small bowel mucosal ischemic injury.

Topics: alpha-Glucosidases; Animals; Cyclosporine; Immunosuppressive Agents; Intestinal Mucosa; Intestine, Small; Ischemia; Male; Polyenes; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Sirolimus; Tumor Necrosis Factor-alpha; Xanthine Oxidase