sirolimus and Ureteral-Obstruction

The global burden of chronic kidney disease is increasing, and the majority of these diseases are progressive. Special site-targeted drugs are emerging as alternatives to traditional drugs. Oligonucleotides (ODNs) have been proposed as effective therapeutic tools in specific molecular target therapies for several diseases. We designed ring-type non-coding RNAs (ncRNAs), also called mTOR ODNs to suppress mammalian target rapamycin (mTOR) translation. mTOR signaling is associated with excessive cell proliferation and fibrogenesis. In this study, we examined the effects of mTOR suppression on chronic renal injury. To explore the regulation of fibrosis and inflammation in unilateral ureteral obstruction (UUO)-induced injury, we injected synthesized ODNs via the tail vein of mice. The expression of inflammatory-related markers (interleukin-1β, tumor necrosis factor-α), and that of fibrosis (α-smooth muscle actin, fibronectin), was decreased by synthetic ODNs. Additionally, ODN administration inhibited the expression of autophagy-related markers, microtubule-associated protein light chain 3, Beclin1, and autophagy-related gene 5-12. We confirmed that ring-type ODNs inhibited fibrosis, inflammation, and autophagy in a UUO mouse model. These results suggest that mTOR may be involved in the regulation of autophagy and fibrosis and that regulating mTOR signaling may be a therapeutic strategy against chronic renal injury.

Topics: Actins; Animals; Autophagy; Beclin-1; Disease Models, Animal; Fibronectins; Fibrosis; Inflammation; Interleukin-1beta; Kidney; Mammals; Mice; Microtubule-Associated Proteins; Oligonucleotides; Renal Insufficiency, Chronic; RNA, Untranslated; Sirolimus; TOR Serine-Threonine Kinases; Tumor Necrosis Factor-alpha; Ureteral Obstruction

In this study, we investigated the effect of mTOR inhibitor (mTORi) drug-eluting biodegradable stent (DE stent), a putative restenosis-inhibiting device for coronary artery, on thermal-injury-related ureteral stricture in rabbits. In vitro evaluation confirmed the dose-dependent effect of mTORi, i.e., rapamycin, on fibrotic markers in ureteral component cell lines. Upper ureteral fibrosis was induced by ureteral thermal injury in open surgery, which was followed by insertion of biodegradable stents, with or without rapamycin drug-eluting. Immunohistochemistry and Western blotting were performed 4 weeks after the operation to determine gross anatomy changes, collagen deposition, expression of epithelial-mesenchymal transition markers, including Smad, α-SMA, and SNAI 1. Ureteral thermal injury resulted in severe ipsilateral hydronephrosis. The levels of type III collagen, Smad, α-SMA, and SNAI 1 were increased 28 days after ureteral thermal injury. Treatment with mTORi-eluting biodegradable stents significantly attenuated thermal injury-induced urinary tract obstruction and reduced the level of fibrosis proteins, i.e., type III collagen. TGF-β and EMT signaling pathway markers, Smad and SNAI 1, were significantly modified in DE stent-treated thermal-injury-related ureteral stricture rabbits. These results suggested that intra-ureteral administration of rapamycin by DE stent provides modification of fibrosis signaling pathway, and inhibiting mTOR may result in fibrotic process change.

Topics: Absorbable Implants; Animals; Drug-Eluting Stents; Fibrosis; Rabbits; Sirolimus; TOR Serine-Threonine Kinases; Ureteral Obstruction

Renal tubule cell apoptosis plays a pivotal role in the progression of chronic renal diseases. The previous study indicates that Sirolimus is effective on unilateral ureteral obstruction (UUO)-induced renal fibrosis. However, the role of Sirolimus in renal tubular apoptosis induced by UUO has not yet been addressed. The aim of this study was to determine the role of Sirolimus in renal tubular apoptosis induced by UUO. Male Sprague-Dawley rats were divided into three groups, sham-operated rats, and after which unilateral ureteral obstruction (UUO) was performed: non-treated and sirolimus-treated (1mg/kg). After 4, 7 and 14 d, animals were sacrificed and blood, kidney tissue samples were collected for analyses. Histologic changes and interstitial collagen were determined microscopically following HE and Masson's trichrome staining. The expression of PCNA was investigated using immunohistochemistry and the expression of Bcl-2, Bax, caspase-9, and caspase-3 were investigated using Western blot in each group. Tubular apoptotic cell deaths were assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay. Sirolimus administration resulted in a significant reduction in tubulointerstitial fibrosis scores. After UUO, there was an increase in tubular and interstitial apoptosis in untreated controls as compared to Sirolimus treatment rats (

Topics: Animals; Apoptosis; Caspase 3; Caspase 9; Immunohistochemistry; In Situ Nick-End Labeling; Kidney; Male; Proliferating Cell Nuclear Antigen; Proto-Oncogene Proteins c-bcl-2; Rats; Sirolimus; Ureteral Obstruction

Kidney injury triggers fibrosis, the final common pathway of chronic kidney disease (CKD). The increase of CKD prevalence worldwide urgently calls for new therapies. Available systemic treatment such as rapamycin are associated with serious side effects. To study the potential of local antifibrotic therapy, we administered rapamycin-loaded microspheres under the kidney capsule of ureter-obstructed rats and assessed the local antifibrotic effects and systemic side effects of rapamycin. After 7 days, microsphere depots were easily identifiable under the kidney capsule. Both systemic and local rapamycin treatment reduced intrarenal mTOR activity, myofibroblast accumulation, expression of fibrotic genes, and T-lymphocyte infiltration. Upon local treatment, inhibition of mTOR activity and reduction of myofibroblast accumulation were limited to the immediate vicinity of the subcapsular pocket, while reduction of T-cell infiltration was widespread. In contrast to systemically administered rapamycin, local treatment did not induce off target effects such as weight loss. Thus subcapsular delivery of rapamycin-loaded microspheres successfully inhibited local fibrotic response in UUO with less systemic effects. Therapeutic effect of released rapamycin was most prominent in close vicinity to the implanted microspheres.

Topics: Animals; Anti-Inflammatory Agents; Capsules; Female; Fibrosis; Gene Expression Regulation; Kidney; Microscopy, Electron, Scanning; Microspheres; Myofibroblasts; Rats, Inbred F344; Sirolimus; T-Lymphocytes; Tissue Distribution; TOR Serine-Threonine Kinases; Treatment Outcome; Ureteral Obstruction

The purpose of this study was to explore effects of rapamycin on renal hypoxia, interstitial inflammation and fibrosis, and the expression of transforming growth factor β1 (TGF-β1), vascular endothelial growth factor (VEGF), Flk-1 and Flt-1 in a rat model of unilateral ureteral obstruction (UUO).. Male Sprague-Dawley rats (n=36) were randomly divided into three groups (n=12 per group): sham surgery, UUO and UUO plus rapamycin (0.2 mg/kg/d). Serum creatinine (Scr), blood urea nitrogen, uric acid, triglycerides, cholesterol and 24-h urine protein levels were measured. The extent of interstitial fibrosis was determined by Masson's trichrome staining. ED-1 positive macrophages, type III collagen, hypoxia, TGF-1, VEGF, Flk-1, and Flt-1 mRNA and protein expressions were detected using immunohistochemical staining, real-time PCR and Western blot.. UUO induced an elevation in Scr, renal hypoxia, inflammation, interstitial fibrosis, TGF-β1, VEGF, Flk-1, and Flt-1 mRNA and protein expression levels (P < 0.05). Rapamycin alleviated the UUO-induced renal hypoxia, infiltration of inflammatory cells and tubulointerstitial fibrosis (at days 3 and 7). Rapamycin also down-regulated the UUO-induced elevated expression levels of TGF-β1 and Flt-1 mRNA and protein (P < 0.05). Rapamycin decreased VEGF mRNA and protein expression at day 3, and increased Flk-1 mRNA and protein expression at day 7, compared with the UUO group (P < 0.05).. Rapamycin shows beneficial effects by reducing UUO-induced renal hypoxia, inflammation and tubulointerstitial fibrosis.

Topics: Animals; Blotting, Western; Fibrosis; Hypoxia; Kidney Diseases; Male; Rats; Rats, Sprague-Dawley; Real-Time Polymerase Chain Reaction; Sirolimus; Transforming Growth Factor beta1; Ureteral Obstruction; Vascular Endothelial Growth Factor Receptor-1

Erdheim-Chester disease is a rare non-Langerhans form of systemic histiocytosis of unknown origin. We describe a 45-year-old man presenting with bilateral hydronephrosis suggestive of extrinsic urinary tract obstruction. Computed tomography revealed extensive hypodense soft tissue infiltration in the retroperitoneum surrounding the kidneys. Needle biopsy of the retroperitoneal soft tissue revealed aggregates of lipid-laden histiocytes expressing CD68 but negative for CD1a and S100 protein. The diagnosis of Erdheim-Chester disease was supported by typical radionuclide bone scinitigraphic findings. Treatment with prednisolone, sirolimus, and regular ureteric stent revision was initiated to achieve adequate urinary tract drainage. To our knowledge, this is the second patient with Erdheim-Chester disease reported in Hong Kong. A high index of suspicion is required to avoid delay in the diagnosis of this rare disease.

Topics: Biopsy, Needle; Erdheim-Chester Disease; Hong Kong; Humans; Hydronephrosis; Male; Middle Aged; Prednisolone; Retroperitoneal Space; Sirolimus; Stents; Tomography, X-Ray Computed; Ureteral Obstruction

Renal interstitial fibrosis is a major determinant of renal failure in the majority of chronic renal diseases. Transforming growth factor-beta (TGF-beta) is the single most important cytokine promoting renal fibrogenesis. Recent in vitro studies identified novel non-smad TGF-beta targets including p21-activated kinase-2 (PAK2), the abelson nonreceptor tyrosine kinase (c-Abl), and the mammalian target of rapamycin (mTOR) that are activated by TGF-beta in mesenchymal cells, specifically in fibroblasts but less in epithelial cells. In the present studies, we show that non-smad effectors of TGF-beta including PAK2, c-Abl, Akt, tuberin (TSC2), and mTOR are activated in experimental unilateral obstructive nephropathy in rats. Treatment with c-Abl or mTOR inhibitors, imatinib mesylate and rapamycin, respectively, each blocks noncanonical (non-smad) TGF-beta pathways in the kidney in vivo and diminishes the number of interstitial fibroblasts and myofibroblasts as well as the interstitial accumulation of extracellular matrix proteins. These findings indicate that noncanonical TGF-beta pathways are activated during the early and rapid renal fibrogenesis of obstructive nephropathy. Moreover, the current findings suggest that combined inhibition of key regulators of these non-smad TGF-beta pathways even in dose-sparing protocols are effective treatments in renal fibrogenesis.

Topics: Animals; Benzamides; Disease Models, Animal; Dose-Response Relationship, Drug; Fibroblasts; Fibrosis; Imatinib Mesylate; Kidney; Kidney Diseases; Male; Piperazines; Proto-Oncogene Proteins c-abl; Pyrimidines; Rats; Rats, Sprague-Dawley; Signal Transduction; Sirolimus; Smad2 Protein; Smad3 Protein; Transcription Factors; Transforming Growth Factor beta; Ureteral Obstruction

Is a common feature of progressive renal diseases regardless of the initiating insult To clarify the role of connective tissue growth factor (CTGF) in after (UUO) in renal interstitial fibrosis and effects of rapamycin (RAP) thereupon.. Eighteen Sprague-Dawley rats were randomly divided into 3 equal groups: unilateral ureteral obstruction (UUO) model group, undergoing ligation of the left ureter; RAP treatment group, undergoing ligation of the left ureter and intraperitoneal injection of RAP 0.04 mg.kg(-1).d(-1); and sham operation group. The right kidneys were taken out 7 and 14 days after the operation respectively to undergo renal pathological examination by Masson staining. Semi-quantitative RT-PCR was used to detect the mRNA expression of CTGF. Western blotting was performed to examine the protein expression of CTGF and fibronectin (FN).. In comparison with the sham operation group, renal interstitial fibrosis was significant more expression in the 2 UUO groups, especially the UUO model group (P < 0.01). Seven and 14 days after the operation the levels of CTGF mRNA expression of the UUO model and RAP treatment groups (both P < 0.01), and the level of CTGF mRNA expression of the RAP treatment group was significantly lower than that of the UUO model group (P < 0.01), however, there was no significant difference in the level of CTGF mRNA expression between the 2 UUO groups 14 days after the operation. Seven and 14 days after the operation the levels of CTGF protein expression of the UUO model and RAP treatment groups were both significantly higher than that of the sham operation group (both P < 0.01), and the levels of CTGF protein expression of the RAP treatment group were significantly lower than that of the UUO model group (P < 0.05 and P < 0.01). The levels of FN expression 7 and 14 days after the operation of the 2 UUO groups were both significantly higher than that of the sham operation group (both P < 0.01). and the level of FN expression 7 days after of the RAP treatment group was significantly lower than that of the UUO model group (P < 0.01), however, there was no significant difference in the level of FN expression between the 2 UUO groups 14 days after the operation.. The expression of CTGF mRNA and that of CTGF protein increase after UUO. Rapamycin play a protective role in the kidney by downregulating the CTGF expression and alleviating the renal interstitial fibrosis following UUO.

Topics: Animals; Blotting, Western; Connective Tissue Growth Factor; Disease Models, Animal; Fibrosis; Gene Expression; Immediate-Early Proteins; Immunosuppressive Agents; Injections, Intraperitoneal; Intercellular Signaling Peptides and Proteins; Kidney; Kidney Diseases; Male; Rats; Rats, Sprague-Dawley; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Sirolimus; Ureteral Obstruction

Unilateral ureteral obstruction (UUO) is a well-characterized hydronephrosis model exhibiting interstitial inflammatory-cell infiltration and tubular dilatation followed by tubulointerstitial fibrosis of the obstructed kidney. Our recent report indicates that rapamycin is effective for 50% of transplant recipients with chronic allograft nephropathy. In this study, we investigate the effect of rapamycin on UUO-induced renal fibrosis. UUO or sham-operated rats were randomly assigned to rapamycin or vehicle and were killed on days 7 and 14 after UUO or sham operation. Rapamycin decreased cross-sectional and gross-morphology changes in the obstructed kidney significantly. Rapamycin markedly blunted the increase in weight of the obstructed kidney, obstructed kidney length, and the obstructed/non-obstructed kidney weight ratio (by 74.6, 42.8, and 61.6% on day 14, respectively, all P<0.01). The scores for tubular dilatation, interstitial volume, interstitial collagen deposition, and alpha-smooth muscle actin (alpha-SMA) after UUO were significantly reduced by rapamycin. Rapamycin also decreased the number of infiltrative anti-ED1-positive cells and the gene expression of transforming growth factor (TGF)-beta1 (84.8 and 80.2% on day 7) after UUO (both P<0.01). By double immunostaining and Western analysis, rapamycin blocked the TGF-beta1-induced loss of E-cadherin expression and de novo increase of the expression of alpha-SMA in a dose-dependent manner. In conclusion, rapamycin significantly attenuated tubulointerstitial damage in a UUO-induced rat model of renal fibrosis, suggesting that rapamycin may have the potential to delay the progression of tubulointerstitial renal fibrosis.

Topics: Animals; Fibrosis; Immunosuppressive Agents; Kidney; Male; Rats; Rats, Sprague-Dawley; Sirolimus; Ureteral Obstruction