adrenomedullin and Fibrosis

Topics: Adrenomedullin; Calcitonin Receptor-Like Protein; Cell Division; Cyclic AMP; Diuresis; Fibrosis; Genetic Therapy; Glomerular Mesangium; Humans; Hypertension, Renal; Intracellular Signaling Peptides and Proteins; Kidney; Kidney Diseases; Membrane Proteins; Natriuresis; Nitric Oxide; Peptides; Receptor Activity-Modifying Proteins; Receptors, Calcitonin; Renal Artery; Vasodilation

Adrenomedullin 2 (AM2; also known as intermedin) is a member of the adrenomedullin (AM) peptide family. Similarly to AM, AM2 partakes in a variety of physiological activities. AM2 has been reported to exert protective effects on various organ disorders; however, its significance in the eye is unknown. We investigated the role of AM2 in ocular diseases. The receptor system of AM2 was expressed more abundantly in the choroid than in the retina. In an oxygen-induced retinopathy model, physiological and pathologic retinal angiogenesis did not differ between AM2-knockout (AM2-/-) and wild-type mice. In contrast, in laser-induced choroidal neovascularization, a model of neovascular age-related macular degeneration, AM2-/- mice had enlarged and leakier choroidal neovascularization lesions, with exacerbated subretinal fibrosis and macrophage infiltration. Contrary to this, exogenous administration of AM2 ameliorated the laser-induced choroidal neovascularization-associated pathology and suppressed gene expression associated with inflammation, fibrosis, and oxidative stress, including that of VEGF-A, VEGFR-2, CD68, CTGF, and p22-phox. The stimulation of human adult retinal pigment epithelial (ARPE) cell line 19 cells with TGF-β2 and TNF-α induced epithelial-to-mesenchymal transition (EMT), whereas AM2 expression was also elevated. The induction of EMT was suppressed when the ARPE-19 cells were pretreated with AM2. A transcriptome analysis identified 15 genes, including mesenchyme homeobox 2 (Meox2), whose expression was significantly altered in the AM2-treated group compared with that in the control group. The expression of Meox2, a transcription factor that inhibits inflammation and fibrosis, was enhanced by AM2 treatment and attenuated by endogenous AM2 knockout in the early phase after laser irradiation. The AM2 treatment of endothelial cells inhibited endothelial to mesenchymal transition and NF-κB activation; however, this effect tended to be canceled following Meox2 gene knockdown. These results indicate that AM2 suppresses the neovascular age-related macular degeneration-related pathologies partially via the upregulation of Meox2. Thus, AM2 may be a promising therapeutic target for ocular vascular diseases.

Topics: Adrenomedullin; Animals; Choroidal Neovascularization; Endothelial Cells; Fibrosis; Humans; Inflammation; Macular Degeneration; Mice; Neuropeptides

Intermedin (IMD), a paracrine/autocrine peptide, protects against cardiac fibrosis. However, the underlying mechanism remains poorly understood. Previous study reports that activation of nucleotide-binding oligomerization domain (NOD)-like receptor family pyrin domain containing 3 (NLRP3) inflammasome contributes to cardiac fibrosis. In this study, we aimed to investigate whether IMD mitigated cardiac fibrosis by inhibiting NLRP3. Cardiac fibrosis was induced by angiotensin II (Ang II) infusion for 2 weeks in rats. Western blot, real-time PCR, histological staining, immunofluorescence assay, RNA sequencing, echocardiography, and hemodynamics were used to detect the role and the mechanism of IMD in cardiac fibrosis. Ang II infusion resulted in rat cardiac fibrosis, shown as over-deposition of myocardial interstitial collagen and cardiac dysfunction. Importantly, NLRP3 activation and endoplasmic reticulum stress (ERS) were found in Ang II-treated rat myocardium. Ang II infusion decreased the expression of IMD and increased the expression of the receptor system of IMD in the fibrotic rat myocardium. IMD treatment attenuated the cardiac fibrosis and improved cardiac function. In addition, IMD inhibited the upregulation of NLRP3 markers and ERS markers induced by Ang II. In vitro, IMD knockdown by small interfering RNA significantly promoted the Ang II-induced cardiac fibroblast and NLRP3 activation. Moreover, silencing of inositol requiring enzyme 1 α (IRE1α) blocked the effects of IMD inhibiting fibroblast and NLRP3 activation. Pre-incubation with PKA pathway inhibitor H89 blocked the effects of IMD on the anti-ERS, anti-NLRP3, and anti-fibrotic response. In conclusion, IMD alleviated cardiac fibrosis by inhibiting NLRP3 inflammasome activation through suppressing IRE1α via the cAMP/PKA pathway.

Topics: Adrenomedullin; Angiotensin II; Animals; Cells, Cultured; Endoribonucleases; Fibrosis; Inflammasomes; Multienzyme Complexes; Neuropeptides; NLR Family, Pyrin Domain-Containing 3 Protein; Protein Serine-Threonine Kinases; Rats

Age-related macular degeneration (AMD) is a leading cause of visual impairment. Anti-vascular endothelial growth factor drugs used to treat AMD carry the risk of inducing subretinal fibrosis. We investigated the use of adrenomedullin (AM), a vasoactive peptide, and its receptor activity-modifying protein 2, RAMP2, which regulate vascular homeostasis and suppress fibrosis. The therapeutic potential of the AM-RAMP2 system was evaluated after laser-induced choroidal neovascularization (LI-CNV), a mouse model of AMD. Neovascular formation, subretinal fibrosis, and macrophage invasion were all enhanced in both AM and RAMP2 knockout mice compared with those in wild-type mice. These pathologic changes were suppressed by intravitreal injection of AM. Comprehensive gene expression analysis of the choroid after LI-CNV with or without AM administration revealed that fibrosis-related molecules, including Tgfb, Cxcr4, Ccn2, and Thbs1, were all down-regulated by AM. In retinal pigment epithelial cells, co-administration of transforming growth factor-β and tumor necrosis factor-α induced epithelial-mesenchymal transition, which was also prevented by AM. Finally, transforming growth factor-β and C-X-C chemokine receptor type 4 (CXCR4) inhibitors eliminated the difference in subretinal fibrosis between RAMP2 knockout and wild-type mice. These findings suggest the AM-RAMP2 system suppresses subretinal fibrosis in LI-CNV by suppressing epithelial-mesenchymal transition.

Topics: Adrenomedullin; Animals; Choroidal Neovascularization; Disease Models, Animal; Epithelial-Mesenchymal Transition; Fibrosis; Humans; Intravitreal Injections; Macular Degeneration; Mice, Knockout; Receptor Activity-Modifying Protein 2; Retinal Pigment Epithelium

Renal fibrosis promotes the progression of chronic renal disease to end-stage renal disease. Microvascular damage and loss play an important role in renal fibrosis. Intermedin (IMD) is expressed mainly in the heart and kidney. IMD has been shown to increase renal blood flow and reduce the loss of glomerular and surrounding renal tubules, but its role in mediating microvascular damage in renal fibrosis remains to be elucidated. Here, we investigated the effects of IMD on microvascular damage in a renal fibrosis model.. We created a rat model of unilateral ureteral obstruction (UUO) to clarify the effect of microvascular damage on renal fibrosis and the effect of intermedin on reversing renal vascular injury and promoting angiogenesis. Rats were divided randomly into three groups: sham, UUO, and UUO + IMD. The sham group underwent free ureteral ligation but not occlusion. Rats in the latter two groups underwent UUO, and rats in the IMD group were additionally administered intermedin (100 ng/kg/h) daily. On the 7th, 14th, 21st, and 28th days after surgery, abdominal aortic blood and the obstructed kidneys were harvested from the rats (n = 6) for analysis.. IMD was found to protect against renal vascular injury and to increase microvessel density. Molecularly, IMD upregulated vascular endothelial growth factor-vascular endothelial growth factor receptor (VEGF-VEGFR2) pathway activity. The VEGF-VEGFR2 pathway might be the underlying mechanism mediating the protective activities of IMD in promoting angiogenesis, delaying renal fibrosis, and improving renal function.. IMD could be a potential candidate treatment for renal fibrosis.

Topics: Adrenomedullin; Animals; Disease Models, Animal; Fibrosis; Kidney; Kidney Diseases; Kidney Tubules; Male; Neovascularization, Pathologic; Neuropeptides; Rats; Rats, Wistar; Up-Regulation; Ureteral Obstruction; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor Receptor-2

Previous studies of the authors have indicated that the transplantation of mesenchymal stem cells (MSCs) can attenuate cardiac fibrosis through the secretion of antifibrotic factors, such as adrenomedullin (ADM). Therefore, the authors addressed the hypothesis that ADM overexpression could enhance the antifibrotic effect of MSCs transplantation in a rat model of heart failure. The results of the present study demonstrated that, compared with the group that received the GFP‑MSCs, the transplantation of ADM‑MSCs significantly improved heart function and decreased the percentage of fibrotic area and the expression of matrix metalloproteinase 2. In addition, fluorescence microscopy indicated that the survival of transplanted MSCs also increased significantly in the ADM‑MSCs‑treated group. Furthermore, the expression of fibrosis‑related genes, such as ADM and hepatocyte growth factor, were significantly influenced in the ADM‑MSCs‑treated group. Based on these findings, it may be concluded that, compared with MSCs, MSCs overexpressing ADM can further improve heart function in rats experiencing heart failure through enhanced antifibrotic activity.

Topics: Adrenomedullin; Animals; Cell Survival; Cells, Cultured; Fibrillar Collagens; Fibrosis; Gene Expression; Heart Failure; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Myocardium; Paracrine Communication; Rats, Wistar; Stroke Volume; Transduction, Genetic

Intermedin [IMD, adrenomedullin-2 (ADM-2)] attenuates renal fibrosis by inhibition of oxidative stress. However, the precise mechanisms remain unknown. Heme oxygenase-1 (HO-1), an antioxidant agent, is associated with antifibrogenic effects. ADM is known to induce HO-1. Whether IMD has any effect on HO-1 is unclear. Herein, we determined whether the antifibrotic properties of IMD are mediated by induction of HO-1.. Renal fibrosis was induced by unilateral ureteral obstruction (UUO) performed on male Wistar rats. Rat proximal tubular epithelial cell line (NRK-52E) was exposed to rhTGF-β1 (10 ng/ml) to establish an in vitro model of epithelial-mesenchymal transition (EMT). IMD was over-expressed in vivo and in vitro using the vector pcDNA3.1-IMD. Zinc protoporphyrin (ZnPP) was used to block HO-1 enzymatic activity. IMD effects on HO-1 expression in the obstructed kidney of UUO rat and in TGF-β1-stimulated NRK-52E were analyzed by real-time RT-PCR, Western blotting or immunohistochemistry. HO activity in the obstructed kidney, contralateral kidney of UUO rat and NRK-52E was examined by measuring bilirubin production. Renal fibrosis was determined by Masson trichrome staining and collagen I expression. Macrophage infiltration and IL-6 expression were evaluated using immunohistochemical analysis. In vivo and in vitro EMT was assessed by measuring α-smooth muscle actin (α-SMA) and E-cadherin expression using Western blotting or immunofluorescence, respectively.. HO-1 expression and HO activity were increased in IMD-treated UUO kidneys or NRK-52E. The obstructed kidneys of UUO rats demonstrated significant interstitial fibrosis on day 7 after operation. In contrast, kidneys that were treated with IMD gene transfer exhibited minimal interstitial fibrosis. The obstructed kidneys of UUO rats also had greater macrophage infiltration and IL-6 expression. IMD restrained infiltration of macrophages and expression of IL-6 in UUO kidneys. The degree of EMT was extensive in obstructed kidneys of UUO rats as indicated by decreased expression of E-cadherin and increased expression of α-SMA. In vitro studies using NRK-52E confirmed these observations. EMT was suppressed by IMD gene delivery. However, all of the above beneficial effects of IMD were eliminated by ZnPP, an inhibitor of HO enzyme activity.. This study demonstrates that IMD attenuates renal fibrosis by induction of HO-1.

Topics: Adrenomedullin; Animals; Cells, Cultured; Enzyme Induction; Fibrosis; Gene Transfer Techniques; Heme Oxygenase (Decyclizing); Kidney Diseases; Male; Neuropeptides; Random Allocation; Rats; Rats, Wistar; Ureteral Obstruction

NADPH oxidase Nox4-derived reactive oxygen species (ROS) play important roles in renal fibrosis. Our previous study demonstrated that intermedin (IMD) alleviated unilateral ureteral obstruction (UUO)-induced renal fibrosis by inhibition of ROS. However, the precise mechanisms remain unclear. Herein, we investigated the effect of IMD on Nox4 expression and NADPH oxidase activity in rat UUO model, and explored if these effect were achieved through cAMP-PKA pathway, the important post-receptor signal transduction pathway of IMD, in TGF-β1-stimulated rat proximal tubular cell (NRK-52E). Renal fibrosis was induced by UUO. NRK-52E was exposed to rhTGF-β1 to establish an in vitro model of fibrosis. IMD was overexpressed in the kidney and in NRK-52E by IMD gene transfer. We studied UUO-induced ROS by measuring dihydroethidium levels and lipid peroxidation end-product 4-hydroxynonenal expression. Nox4 expression in the obstructed kidney of UUO rat or in TGF-β1-stimulated NRK-52E was measured by quantitative RT-PCR and Western blotting. We analyzed NADPH oxidase activity using a lucigenin-enhanced chemiluminescence system. We showed that UUO-stimulated ROS production was remarkably attenuated by IMD gene transfer. IMD overexpression inhibited UUO-induced up-regulation of Nox4 and activation of NADPH oxidase. Consistent with in vivo results, TGF-β1-stimulated increase in Nox4 expression and NADPH oxidase activity was blocked by IMD. In NRK-52E, these beneficial effects of IMD were abolished by pretreatment with N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide hydrochloride (H-89), a PKA inhibitor, and mimicked by a cell-permeable cAMP analog dibutyl-cAMP. Our results indicate that IMD exerts anti-oxidant effects by inhibition of Nox4, and the effect can be mediated by cAMP-PKA pathway.

Topics: 8-Bromo Cyclic Adenosine Monophosphate; Adrenomedullin; Aldehydes; Animals; Cell Line; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Ethidium; Fibrosis; Gene Transfer Techniques; Isoquinolines; Kidney; Kidney Diseases; Lipid Peroxidation; Male; NADPH Oxidase 4; Neuropeptides; Oxidative Stress; Rats; Rats, Wistar; Reactive Oxygen Species; Real-Time Polymerase Chain Reaction; Signal Transduction; Sulfonamides; Transforming Growth Factor beta1; Up-Regulation

BACKGROUND Myocardial fibrosis is the result of persistent anoxia and ischemic myocardial fibers caused by coronary atherosclerotic stenosis, which lead to heart failure, threatening the patient's life. This study aimed to explore the regulatory role of intermedin 1-53 (IMD1-53) in cardiac fibrosis using neonatal rat cardiac fibroblasts and a myocardial infarction (MI) rat model both in vitro and in vivo. MATERIAL AND METHODS The Western blot method was used to detect the protein expression of collagen I and collagen III in myocardial fibroblasts. The SYBR Green I real-time quantitative polymerase chain reaction (PCR) assay was used to detect the mRNA expression of collagen type I and III, IMD1-53 calcitonin receptor-like receptor (CRLR), transforming growth factor-β (TGF-β), and matrix metalloproteinase-2 (MMP-2). Masson staining was used to detect the area changes of myocardial fibrosis in MI rats. RESULTS Results in vivo showed that IMD1-53 reduced the scar area on the heart of MI rats and inhibited the expression of collagen type I and III both in mRNA and protein. Results of an in vitro study showed that IMD1-53 inhibited the transformation of cardiomyocytes into myofibroblasts caused by angiotensin II (Ang II). The further mechanism study showed that IMD1-53 inhibited the expression of TGF-β and the phosphorylation of smad3, which further up-regulated the expression of MMP-2. CONCLUSIONS IMD1-53 is an effective anti-fibrosis hormone that inhibits cardiac fibrosis formation after MI by down-regulating the expression of TGF-β and the phosphorylation of smad3, blocking fibrous signal pathways, and up-regulating the expression of MMP-2, thereby demonstrating its role in regression of myocardial fibrosis.

Topics: Adrenomedullin; Animals; Cardiomyopathies; Collagen; Down-Regulation; Fibroblasts; Fibrosis; Heart Failure; Male; Myocardial Infarction; Myocardium; Neuropeptides; Rats; Rats, Sprague-Dawley; Signal Transduction; Transforming Growth Factor beta1

Transforming growth factor-β1 (TGF-β1) plays a pivotal role in the progression of renal fibrosis. Reactive oxygen species mediate profibrotic action of TGF-β1. Intermedin (IMD) has been shown to inhibit oxidative stress, but its role in renal fibrosis remains unclear. Here, we investigated the effects of IMD on renal fibrosis in a rat model of unilateral ureteral obstruction (UUO).. The expression of IMD and its receptors, calcitonin receptor-like receptor (CRLR) and receptor activity-modifying proteins (RAMP1/2/3), in the obstructed kidney was detected by real-time polymerase chain reaction (PCR), western blotting and immunohistochemistry. To evaluate the effects of IMD on renal fibrosis, we locally overexpressed exogenous IMD in the obstructed kidney using an ultrasound-microbubble-mediated delivery system. Renal fibrosis was determined by Masson trichrome staining. The expression of TGF-β1, connective tissue growth factor (CTGF), α-smooth muscle actin (α-SMA) and fibronectin was measured. Smad2/3 activation and macrophage infiltration were evaluated. We also studied oxidative stress by measuring superoxide dismutase (SOD) activity and malondialdehyde (MDA) content.. mRNA and protein expression of IMD increased after UUO. CRLR, RAMP1, RAMP2 and RAMP3 were also induced by ureteral obstruction. IMD overexpression remarkably attenuated UUO-induced tubular injury and blunted fibrotic response as shown by decreased interstitial collagen deposition and downregulation of fibronectin. Macrophage infiltration, α-SMA and CTGF upregulation caused by UUO were all relieved by IMD, whereas TGF-β1 upregulation and Smad2/3 activation were not affected. Meanwhile, we noted increased oxidative stress in obstruction, which was also attenuated by IMD gene delivery.. Our results indicate that IMD is upregulated after UUO. IMD plays a protective role in renal fibrosis via its antioxidant effects.

Topics: Adrenomedullin; Animals; Calcitonin Receptor-Like Protein; Collagen; Disease Models, Animal; Fibronectins; Fibrosis; Genetic Therapy; Kidney; Kidney Diseases; Male; Microbubbles; Neuropeptides; Oxidative Stress; Rats, Wistar; Receptor Activity-Modifying Protein 1; Receptor Activity-Modifying Protein 2; Receptor Activity-Modifying Protein 3; RNA, Messenger; Signal Transduction; Smad2 Protein; Smad3 Protein; Time Factors; Transfection; Transforming Growth Factor beta1; Ultrasonics; Up-Regulation; Ureteral Obstruction

Pulmonary hypertension (PH) causes mortality in systemic sclerosis (SSc). Pulmonary arterial hypertension (PAH) and left heart disease (LHD) are frequent causes of PH. Therefore, we studied PAH and LHD in early PH.. A total of 432 French Canadian SSc patients were studied retrospectively. All underwent screening for PH. We analysed clinical, serological, and radiographic data from 26 patients with early PH diagnosed by right heart catheterization (RHC). SSc patients with (n = 21) and without PH (n = 19) were prospectively re-evaluated by cardiac magnetic resonance imaging (MRI) and serial measurements of N-terminal pro-brain natriuretic peptide (NT-proBNP) and the haemodynamic biomarkers mid-regional pro-atrial natriuritic peptide (MR-proANP) and mid-regional pro-adrenomedullin (MR-proADM).. The most frequent cause of early PH was LHD (58%). PAH was seen in 34% of patients. No association was found between the type of PH and autoantibodies. Early LHD-PH, but not early PAH, was associated with lower NT-proBNP (p = 0.024), but MR-proANP and MR-proADM levels were higher in early LHD-PH than in patients without PH (p = 0.014 and p = 0.012, respectively). Only one patient had abnormal cardiac MRI explaining LHD-PH.. Early PH in SSc, like late PH, is heterogeneous and RHC is essential for determining its underlying cause. The most frequent cause of early PH was LHD. Levels of MR-proANP and MR-proADM, but not NT-proBNP, were increased in early LHD-PH, and may be more reliable than NT-proBNP as a biomarker of early PH in this subgroup of patients. Cardiac MRI did not explain LHD-PH. This study is the first to identify a high frequency of LHD in early PH correlating with normal NT-proBNP levels but increased MR-proANP and MR-proADM levels in SSc patients.

Topics: Adrenomedullin; Adult; Aged; Biomarkers; Canada; Female; Fibrosis; Heart Diseases; Humans; Hypertension, Pulmonary; Magnetic Resonance Imaging, Cine; Male; Middle Aged; Myocardium; Natriuretic Peptide, Brain; Peptide Fragments; Retrospective Studies; Scleroderma, Systemic

Revealing the mechanisms underlying the functional integrity of the vascular system could make available novel therapeutic approaches. We previously showed that knocking out the widely expressed peptide adrenomedullin (AM) or receptor activity-modifying protein 2 (RAMP2), an AM-receptor accessory protein, causes vascular abnormalities and is embryonically lethal. Our aim was to investigate the function of the vascular AM-RAMP2 system directly.. We generated endothelial cell-specific RAMP2 and AM knockout mice (E-RAMP2(-/-) and E-AM(-/-)). Most E-RAMP2(-/-) mice died perinatally. In surviving adults, vasculitis occurred spontaneously. With aging, E-RAMP2(-/-) mice showed severe organ fibrosis with marked oxidative stress and accelerated vascular senescence. Later, liver cirrhosis, cardiac fibrosis, and hydronephrosis developed. We next used a line of drug-inducible E-RAMP2(-/-) mice (DI-E-RAMP2(-/-)) to induce RAMP2 deletion in adults, which enabled us to analyze the initial causes of the aforementioned vascular and organ damage. Early after the induction, pronounced edema with enhanced vascular leakage occurred. In vitro analysis revealed the vascular leakage to be caused by actin disarrangement and detachment of endothelial cells. We found that the AM-RAMP2 system regulates the Rac1-GTP/RhoA-GTP ratio and cortical actin formation and that a defect in this system causes the disruption of actin formation, leading to vascular and organ damage at the chronic stage after the gene deletion.. Our findings show that the AM-RAMP2 system is a key determinant of vascular integrity and homeostasis from prenatal stages through adulthood. Furthermore, our models demonstrate how endothelial cells regulate vascular integrity and how their dysregulation leads to organ damage.

Topics: Adrenomedullin; Age Factors; Aging; Animals; Antigens, CD; Arteriosclerosis; Cadherins; Disease Models, Animal; Edema; Endothelium, Vascular; Fibrosis; Glomerulosclerosis, Focal Segmental; Homeostasis; Kidney; Leukocytes; Mice; Mice, Knockout; Oxidative Stress; Receptor Activity-Modifying Protein 2; Vasculitis

We aimed to determine the diagnostic performance of biomarkers in predicting myocardial fibrosis assessed by late gadolinium enhancement (LGE) cardiovascular magnetic resonance imaging (CMR) in patients with hypertrophic cardiomyopathy (HCM). LGE CMR was performed in 40 consecutive patients with HCM. Left and right ventricular parameters, as well as the extent of LGE were determined and correlated to the plasma levels of midregional pro-atrial natriuretic peptide (MR-proANP), midregional pro-adrenomedullin (MR-proADM), carboxy-terminal pro-endothelin-1 (CT-proET-1), carboxy-terminal pro-vasopressin (CT-proAVP), matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinase-1 (TIMP-1) and interleukin-8 (IL-8). Myocardial fibrosis was assumed positive, if CMR indicated LGE. LGE was present in 26 of 40 patients with HCM (65%) with variable extent (mean: 14%, range: 1.3-42%). The extent of LGE was positively associated with MR-proANP (r = 0.4; P = 0.01). No correlations were found between LGE and MR-proADM (r = 0.1; P = 0.5), CT-proET-1 (r = 0.07; P = 0.66), CT-proAVP (r = 0.16; P = 0.3), MMP-9 (r = 0.01; P = 0.9), TIMP-1 (r = 0.02; P = 0.85), and IL-8 (r = 0.02; P = 0.89). After adjustment for confounding factors, MR-proANP was the only independent predictor associated with the presence of LGE (P = 0.007) in multivariate analysis. The area under the ROC curve (AUC) indicated good predictive performance (AUC = 0.882) of MR-proANP with respect to LGE. The odds ratio was 1.268 (95% confidence interval 1.066-1.508). The sensitivity of MR-proANP at a cut-off value of 207 pmol/L was 69%, the specificity 94%, the positive predictive value 90% and the negative predictive value 80%. The results imply that MR-proANP serves as a novel marker of myocardial fibrosis assessed by LGE CMR in patients with HCM.

Topics: Adrenomedullin; Adult; Aged; Atrial Natriuretic Factor; Biomarkers; Cardiomyopathy, Hypertrophic; Contrast Media; Endothelin-1; Female; Fibrosis; Gadolinium DTPA; Germany; Glycopeptides; Humans; Interleukin-8; Logistic Models; Magnetic Resonance Imaging, Cine; Male; Matrix Metalloproteinase 9; Middle Aged; Myocardium; Odds Ratio; Predictive Value of Tests; Protein Precursors; ROC Curve; Stroke Volume; Tissue Inhibitor of Metalloproteinase-1; Ventricular Function, Left

Statins exert pleiotropic effects, including antioxidative and cellular protective effects. Endogenous adrenomedullin (AM) induces anti-inflammatory, anti-fibrotic and proangiogenic effects. We examined the effects of simvastatin on cardiac fibrosis and apoptosis in AM heterozygous knockout (AM(+/-)) mice treated with angiotensin (Ang) II and high salt loading. Seven-week-old AM(+/-) mice were infused with Ang II while on a high-salt diet with or without simvastatin for 2 weeks. Hearts were stained by hematoxylin-eosin or Masson's trichrome, and were immunostained with isolectin B(4) and α-smooth muscle actin antibodies. Expression of c-Kit and Sca-1 messenger RNA (mRNA) was evaluated by real-time PCR analysis. Apoptotic cells in hearts were identified by terminal deoxynucleotidyl transferase-mediated UTP end labeling (TUNEL) staining. Hearts from Ang II/salt loading AM(+/-) mice showed marked perivascular fibrosis around coronary arteries. Treatment with simvastatin significantly inhibited the fibrosis around coronary arteries in Ang II/salt-loading AM(+/-) mice. Expression of c-Kit and Sca-1 mRNAs in hearts from Ang II/salt-loading AM(+/-) mice was significantly lower than in hearts from wild-type mice. Treatment with simvastatin significantly increased the suppressed expression of c-Kit and Sca-1 mRNAs. In addition, treatment with simvastatin significantly increased the number of isolectin B(4)-positive capillary arteries in hearts from Ang II/salt-loading AM(+/-) mice. Ang II/high salt significantly increased apoptotic cells in hearts from AM(+/-) mice; this trend was reversed by treatment with simvastatin. Thus, statins have potent cardioprotective effects that may be associated with anti-fibrotic, proangiogenic and anti-apoptotic effects in Ang II/salt-loading AM(+/-) mice.

Topics: Actins; Adrenomedullin; Angiotensin II; Animals; Antigens, Ly; Apoptosis; Capillaries; Coronary Vessels; Fibrosis; Glycoproteins; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Male; Membrane Proteins; Mice; Mice, Knockout; Myocardium; Proto-Oncogene Proteins c-kit; Simvastatin; Sodium Chloride, Dietary; Treatment Outcome

Adrenomedullin (AM) is a regulatory peptide involved in cellular proliferation and protein synthesis. The authors investigated AM and the AM receptor system in the human fetal lung fibroblasts (HFLFs), and assessed whether AM can inhibit proliferation and collagen synthesis in HFLFs under hypoxia. Fibroblasts were exposed to hypoxia (2% O(2)) after the addition of AM. The effects of AM and transforming growth factor β1 (TGF-β1) on the proliferation of fibroblasts were determined by the methanethiosulfonate (MTS) assay. Total collagen synthesis was determined by [(3)H]proline incorporation. TGF-β1 levels in the culture supernatant were measured by enzyme-linked immunosorbent assay (ELISA). The concentration of intracellular calciumion ([Ca(2+)](i)) in fibroblasts was detected with a laser scanning confocal microscope. AM, adrenomedullin receptor (ADMR), calcitonin receptor-like receptor (CRLR), AM receptor chaperone receptor activity-modifying protein-1 (RAMP1),RAMP2, and RAMP3 were detected in the HFLFs. The hypoxia-induced increases in cell proliferation, collagen synthesis, and TGF-β1 production were inhibited by AM. AM also inhibited proliferation and collagen synthesis in fibroblasts induced by TGF-β1. AM caused a decrease of the hypoxia-induced [Ca(2+)](i) in fibroblasts. This study suggests that AM is produced by HFLFs and AM may function as an antifibrosis factor that protects cells from hypoxic pulmonary damage through its receptors.

Topics: Adrenomedullin; Calcitonin Receptor-Like Protein; Calcium; Cell Growth Processes; Cell Hypoxia; Collagen; Fibroblasts; Fibrosis; Humans; Lung; Receptor Activity-Modifying Proteins; Receptors, Adrenomedullin; Transforming Growth Factor beta1

We aimed to investigate the mechanism mediating the antifibrotic effects of mesenchymal stem cells (MSCs) via in vitro and in vivo study.. In vitro, cardiac fibroblasts (CFs) from passage 2 were cultured and incubated with DMEM/F12 supplemented with 10% fetal bovine serum (DM-10), DM-10 containing angiotensin II (Ang II, 1 x 10(-6) M) or a combination of MSC-conditioned medium (MSC-CM) and Ang II (1 x 10(-6) M) for 48 h. CFs proliferation and gene expression of collagen I and III were analyzed by MTT and reverse transcription-polymerase chain reaction (RT-PCR). In vivo, global heart failure was induced in Wistar rats by isoproterenol (ISO) injection. Four weeks later, MSCs or culture medium were transplanted by intramyocardial injection. Four weeks after transplantation, heart function was assessed, and histological analysis conducted. In addition, the expression of adrenomedullin (ADM), an antifibrotic factor, in MSCs and myocardium were also examined.. In vitro, MSCs expressed ADM. MSC-CM obviously inhibited CFs proliferation and expression of collagen I and III mRNA. In vivo, compared with medium transplantation, MSC transplantation significantly improved heart function, decreased collagen volume fraction and increased expression of ADM in myocardium.. MSC transplantation can inhibit function of CFs by secreting antifibrotic factors such as ADM, resulting in decrease of myocardial fibrosis.

Topics: Adrenomedullin; Animals; Apoptosis; Cell Shape; Cells, Cultured; Disease Models, Animal; Fibrosis; Gene Expression Regulation; Heart Failure; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Paracrine Communication; Rats; Rats, Wistar

Systemic administration of the potent vasodilating peptide adrenomedullin reduces cardiac and renal fibrosis in hypertensive animals. Here, we investigated the effects of kidney-specific adrenomedullin gene delivery in normotensive rats after unilateral ureteral obstruction, an established model of renal tubulointerstitial fibrosis. Overexpression of exogenous adrenomedullin in the renal interstitium following ureteral obstruction significantly prevented fibrosis and proliferation of tubular and interstitial cells. In this model, there is upregulation of connective tissue growth factor (CTGF) mRNA expression and extracellular signal-regulated kinase (ERK) phosphorylation, and adrenomedullin overexpression suppressed both of these activities without altering the blood pressure. In NRK-49F renal fibroblasts, adrenomedullin reduced transforming growth factor-beta-induced CTGF and fibronectin mRNA upregulation through the cyclic AMP/protein kinase A signaling pathway, and suppressed ERK phosphorylation and cell proliferation. In the kidneys with an obstructed ureter, adrenomedullin receptor gene expression was upregulated along with cyclic AMP production in kidney slices. The latter effect was partially blocked by a neutralizing antibody to adrenomedullin, indicating that an endogenous peptide-receptor system was activated. Our results show that overexpression of exogenous adrenomedullin in the ureteral-obstructed kidney prevents tubulointerstitial fibrosis and cell proliferation through the cyclic AMP-mediated decrease of CTGF induction and ERK phosphorylation.

Topics: Adrenomedullin; Animals; Connective Tissue Growth Factor; Extracellular Signal-Regulated MAP Kinases; Fibrosis; Gene Expression Regulation; Humans; Immediate-Early Proteins; Intercellular Signaling Peptides and Proteins; Kidney Diseases; Male; Rats; Rats, Wistar; Transfection

Identification of isolated congenital heart block (CHB) predicts, with near certainty, the presence of maternal anti-SSA/Ro antibodies; however, the 2% incidence of CHB in first offspring of anti-SSA/Ro+ mothers, 20% recurrence in subsequent pregnancies, and discordance in identical twins suggest that an environmental factor amplifies the effect of the antibody. Accordingly, this study was carried out to explore the hypothesis that hypoxia potentiates a profibrosing phenotype of the fetal cardiac fibroblast.. Evidence of an effect of hypoxia was sought by immunohistologic evaluation of CHB-affected fetal heart tissue and by determination of erythropoietin levels in cord blood. The in vitro effect of hypoxia on gene expression and phenotype in fibroblasts derived from fetal hearts and lungs was investigated by Affymetrix arrays, quantitative polymerase chain reaction (PCR), immunofluorescence, and immunoblotting.. In vivo hypoxic exposure was supported by the prominent intracellular fibroblast expression of hypoxia-inducible factor 1alpha in conduction tissue from 2 fetuses in whom CHB led to death. The possibility that hypoxia was sustained was suggested by significantly elevated erythropoietin levels in cord blood from CHB-affected, as compared with unaffected, anti-SSA/Ro-exposed neonates. In vitro exposure of cardiac fibroblasts to hypoxia resulted in transdifferentiation to myofibroblasts (a scarring phenotype), as demonstrated on immunoblots and immunofluorescence by increased expression of smooth muscle actin (SMA), an effect not seen in lung fibroblasts. Hypoxia-exposed cardiac fibroblasts expressed adrenomedullin at 4-fold increased levels, as determined by Affymetrix array, quantitative PCR, and immunofluorescence, thus focusing attention on cAMP as a modulator of fibrosis. MDL12,330A, an adenylate cyclase inhibitor that lowers the levels of cAMP, increased expression of fibrosis-related proteins (mammalian target of rapamycin, SMA, plasminogen activator inhibitor type 1, and type I collagen), while the cAMP activator forskolin attenuated transforming growth factor beta-elicited fibrosing end points in the cardiac fibroblasts.. These findings provide evidence that hypoxia may amplify the injurious effects of anti-SSA/Ro antibodies. Modulation of cAMP may be a key component in the scarring phenotype. Further assessment of the susceptibility of cardiac fibroblasts to cAMP modulation offers a new research direction in CHB.

Topics: Actins; Adrenomedullin; Antibodies, Antinuclear; Autoimmunity; Cell Hypoxia; Cell Transdifferentiation; Cells, Cultured; Cyclic AMP; Disease Progression; Erythropoietin; Fibroblasts; Fibrosis; Heart; Heart Block; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Lung; RNA, Messenger; Transforming Growth Factor beta

Produced by vascular walls, adrenomedullin (AM) exerts antifibrotic actions in the process of cardiovascular remodeling. The purpose of this study was to examine the pathophysiological role of AM in the development of human abdominal aortic aneurysm (AAA).. Immunohistochemical analyses revealed that vascular smooth muscle cells in the media were positive for AM in the early stage of atherosclerotic aorta. Intense immunoreactivity was observed in mast cells of the outer media and adventitia of AAA, and the number of mast cells was greater (p < 0.01) in AAA than in atherosclerotic aorta without any aneurysmal change. To determine the role of AM in mast cells, we examined cultured human mast cell leukemia line-1 (HMC-1) and fibroblasts isolated from AAA patients. Cultured HMC-1 cells were found to express preproAM gene and release AM peptide into the cultured media. When assessed by collagenase-sensitive [3H]proline incorporation and procollagen type I C-peptide secretion, collagen synthesis in co-culture of HMC-1 and the fibroblasts was reduced by 10(-6) mol/L synthetic AM, while conversely, it increased following blockade of the action of endogenous AM with 10 microg/mL anti-AM monoclonal antibody.. The present study suggests an anti-fibrotic role for AM released from mast cells, providing new insight into the biological actions of mast cell-derived AM in the development of AAA.

Topics: Adrenomedullin; Aorta, Abdominal; Aortic Aneurysm, Abdominal; Atherosclerosis; Cell Line, Tumor; Cells, Cultured; Collagen; Fibrosis; Humans; Immunohistochemistry; Mast Cells; Peptides; Protein Biosynthesis; Protein Precursors; Proteins; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger

Adrenomedullin (ADM) is a vasodilator peptide that is abundantly expressed in the kidney. ADM has antiproliferative effects on glomerular mesangial cells (MC) in vitro. Whether or not treatment with ADM can reduce MC proliferation in vivo [i.e., in mesangioproliferative glomerulonephritis (GN)] is unknown. We tested the hypothesis that ADM substitution reduces MC proliferation in GN.. GN in rats was induced by injection of an anti-Thy-1.1 antibody. Rats received osmotic minipumps, which continuously delivered rat ADM (500 ng/hour, N = 11), or vehicle (N = 13) from day 3 to day 6 after GN induction. Rats were sacrificed 6 days after induction of GN. On kidney sections, cells staining positive for proliferating cell nuclear antigen, mesangial cells, monocytes, and apoptotic cells were counted. Parameters of inflammation and fibrosis were measured in renal cortex and sieved glomeruli by real-time polymerase chain reaction (PCR).. Systolic blood pressure, diuresis, albuminuria, creatinine clearance, microaneurysm formation, and mesangial matrix expansion were not influenced by ADM infusion. However, ADM treatment significantly reduced the number of MC, showed a tendency to reduce total glomerular cell proliferation, and significantly increased apoptosis. ADM-treated GN animals showed significantly less glomerular monocyte infiltration. ADM treatment normalized transforming growth factor (TGF)-beta1 mRNA expression and reduced monocyte chemoattractant protein-1 (MCP-1), osteopontin, plasminogen activator inhibitor-1 (PAI-1), collagen I, and collagen III mRNA expression significantly.. Exogenous ADM infusion reduces MC number and glomerular monocyte infiltration in the state of mesangial proliferation during acute experimental mesangioproliferative GN. These findings indicate that ADM can influence the course of mesangioproliferative GN.

Topics: Adrenomedullin; Animals; Body Weight; Cell Count; Fibrosis; Glomerular Mesangium; Glomerulonephritis, Membranoproliferative; Male; Peptides; Rats; Rats, Sprague-Dawley; Urine; Vasodilator Agents

We developed a transgenic (Tg) rat model that overexpresses human proadrenomedullin N-terminal 20 peptide (PAMP) only and then compared the effects of unilateral nephrectomy followed by a high salt diet for five weeks in Tg and wild-type rats. We found that systolic blood pressure was significantly lower in Tg UNX rats and cardiac hypertrophy and myocardial fibrosis was also attenuated in Tg rats. Evaluation of gene expression showed suppression of cardiac local renin-angiotensin system (RAS) in Tg rat. These results suggest that in addition to reducing blood pressure, PAMP suppresses cardiac hypertrophy through negative regulation of the local cardiac RAS.

Topics: Adrenomedullin; Animals; Animals, Genetically Modified; Blood Pressure; Cardiomegaly; Diet; Fibrosis; Humans; Hypertension; Kidney; Myocardium; Peptide Fragments; Protein Precursors; Proteins; Rats; Renin-Angiotensin System; Salts; Transgenes

Adrenomedullin (AM) is a novel vasodilating peptide thought to have important effects on cardiovascular function. The aim of this study was to assess the activity of endogenous AM in the cardiovascular system using AM knockout mice.. Mice heterozygous for an AM-null mutation (AM+/-) and their wild-type littermates were subjected to aortic constriction or angiotensin II (Ang II) infusion. The resultant cardiovascular stress led to increases in heart weight/body weight ratios, left ventricular wall thickness, and perivascular fibrosis, as well as expression of genes encoding angiotensinogen, ACE, transforming growth factor-beta, collagen type I, brain natriuretic peptide, and c-fos. In addition, renal damage characterized by decreased creatinine clearance with glomerular sclerosis was noted. In all cases, the effects were significantly more pronounced in AM+/- mice. Hearts from adult mice subjected to aortic constriction showed enhanced extracellular signal-regulated kinase (ERK) activation, as did cardiac myocytes from neonates treated acutely with Ang II. Again the effect was more pronounced in AM+/- mice, which showed increases in cardiac myocyte size, protein synthesis, and fibroblast proliferation. ERK activation was suppressed by protein kinase C inhibition to a greater degree in AM+/- myocytes. In addition, treatment of cardiac myocytes with recombinant AM suppressed Ang II-induced ERK activation via a protein kinase A-dependent pathway.. Endogenous AM exerts a protective effect against stress-induced cardiac hypertrophy via protein kinase C- and protein kinase A-dependent regulation of ERK activation. AM may thus represent a useful new tool for the treatment of cardiovascular disease.

Topics: Adrenomedullin; Angiotensin II; Angiotensinogen; Animals; Aorta, Abdominal; Cardiomegaly; Collagen Type I; Constriction; Enzyme Activation; Enzyme Inhibitors; Fibroblasts; Fibrosis; Gene Expression Regulation; Genes, fos; Genes, Lethal; Glomerulosclerosis, Focal Segmental; Heterozygote; Male; MAP Kinase Signaling System; Mice; Mice, Knockout; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinases; Myocytes, Cardiac; Natriuretic Peptide, Brain; Peptides; Peptidyl-Dipeptidase A; Protein Kinase C; Proto-Oncogene Proteins c-fos; Transforming Growth Factor beta; Ventricular Remodeling

Recent studies have demonstrated that the activation of protein kinase Akt attenuates myocardial ischemia/reperfusion injury. However, it remains unknown whether adrenomedullin (AM), which is also a potent Akt activator, has cardioprotective effects after ischemia/reperfusion. In the present study, Sprague-Dawley rats were exposed to a 30-min period of ischemia induced by ligation of the left coronary artery followed by 24-h reperfusion. They were randomized to receive intravenous administration of AM (0.05 microg/kg/min) or saline for 60 min after coronary ligation. We examined the hemodynamics and myocardial apoptosis 24 h after ischemia/reperfusion. Echocardiographic measurements were performed 4 weeks after ischemia/reperfusion. Myocardial infarct size was also measured histologically. AM significantly reduced left ventricular (LV) end-diastolic pressure (17 +/- 2 to 8 +/- 2 mmHg, p < 0.05) and the number of apoptotic nuclei in myocytes (387 +/- 39 to 147 +/- 72 per field, p < 0.05). AM significantly increased LV dP/dt(max) (4,803 +/- 228 to 5,672 +/- 199 mmHg/s, p < 0.05). AM significantly increased LV fractional shortening (23 +/- 2 vs. 28 +/- 2%, p < 0.05), and significantly reduced LV diastolic dimension (7.4 +/- 0.1 to 6.9 +/- 0.1 mm, p < 0.05) and myocardial infarct size (33 +/- 2 to 20 +/- 2%, p < 0.01) 4 weeks after ischemia/reperfusion. In conclusion, AM infusion during ischemia/reperfusion attenuated the development of LV remodeling and myocardial fibrosis in rats. Based on these results, the cardioprotective effects of AM may be attributed at least partly to its anti-apoptotic effect.

Topics: Adrenomedullin; Animals; Aorta; Apoptosis; Blood Pressure; Cardiotonic Agents; Fibrosis; Male; Myocardial Infarction; Myocardial Reperfusion Injury; Myocardium; Peptides; Rats; Rats, Sprague-Dawley; Ventricular Remodeling

Adrenomedullin (AM) is a potent vasodilator and natriuretic peptide that plays an important role in cardiovascular function. In this study, we employed a somatic gene delivery approach to explore its potential protective role in renovascular hypertension. A single tail vein injection of adenovirus harboring the human AM gene significantly blunted a blood pressure increase that lasted for more than 3 wk in two-kidney one-clip (2K1C) hypertensive rats. The expression of human AM mRNA was detected in the kidney, adrenal gland, heart, lung, and liver, and immunoreactive human AM was detected in the plasma and urine of 2K1C rats after human AM gene delivery. A maximal blood pressure difference of 28 mmHg was observed 10 days after AM gene delivery, compared with that in rats injected with the control virus carrying the LacZ gene. Human AM gene delivery significantly attenuated increases in the ratio of left ventricular weight to heart weight, cardiomyocyte diameter, and fibrosis in the heart, as well as glomerular sclerosis, tubular injuries, and protein casts in the kidney. The beneficial effects of AM gene delivery were accompanied by increased urinary cAMP levels, indicating activation of AM receptors. These findings provide new insights into the role of AM in renovascular hypertension and may have significance in therapeutic applications in cardiovascular diseases.

Topics: Adenoviridae; Adrenomedullin; Animals; Blood Pressure; Cardiomegaly; Disease Models, Animal; Fibrosis; Gene Expression; Gene Transfer Techniques; Genetic Therapy; Glomerulosclerosis, Focal Segmental; Humans; Hypertension, Renovascular; Male; Organ Size; Peptides; Radioimmunoassay; Rats; Rats, Wistar; RNA, Messenger

Adrenomedullin (AM) is a potent vasodilator expressed in tissues relevant to cardiac and renal functions. Our previous study showed that delivery of the human AM gene in the form of naked DNA caused a prolonged reduction of blood pressure in genetically hypertensive rats. In this study, we evaluated potential protective effects of adenovirus-mediated AM gene delivery on salt-induced cardiorenal lesions in hypertensive Dahl saltsensitive (DSS) rats. Adenovirus carrying the human AM cDNA under the control of the cytomegalovirus promoter-enhancer (Ad.CMV-hAM) was generated by homologous recombination of E. coli. Expression of recombinant human AM was detected by a radioimmunoassay in the medium of human embryonic kidney 293 cells transfected with Ad.CMV-hAM. A single intravenous injection of Ad.CMV-hAM caused a significant reduction of systolic blood pressure for 4 weeks in DSS rats compared with control rats with or without injection of adenovirus carrying the green fluorescent protein gene. AM gene delivery significantly reduced left ventricular mass and urinary protein, increased cAMP levels, and enhanced renal function as evidenced by increases in glomerular filtration rate and renal blood flow. Morphological investigations showed that AM gene transfer reduced cardiomyocyte diameter and interstitial fibrosis in the heart as well as glomerular sclerosis, tubular disruption, and protein cast accumulation in the kidney. Expression of human AM mRNA was identified in rat heart, kidney, lung, liver, and aorta, and immunoreactive human AM levels were measured in rat plasma and urine. These results indicate that human AM gene delivery protects against salt-induced hypertension and cardiac and renal lesions in DSS rats via activation of cAMP as a second messenger. These findings provide new insights into the role of AM in salt-induced hypertension and may have implications in therapeutic applications to salt-related cardiovascular and renal diseases.

Topics: Adenoviridae; Adrenomedullin; Animals; Blood Pressure; Cardiomegaly; Cell Line; Cyclic AMP; Fibrosis; Genetic Therapy; Humans; Hypertension; Kidney; Kidney Function Tests; Male; Peptides; Proteinuria; Rats; Rats, Inbred Dahl; Recombinant Proteins; Salts

Adrenomedullin (AM) is a potent vasodilator and natriuretic peptide that plays an important role in cardiorenal function. In this study, we explored the potential protective role of AM in volume-dependent hypertension by somatic gene delivery. Adenovirus containing the human AM cDNA under the control of the cytomegalovirus promoter/enhancer was administered into deoxycorticosterone acetate (DOCA)-salt hypertensive rats via tail vein injection. A single injection of the human AM gene resulted in a prolonged reduction of blood pressure with a maximal reduction of 41 mm Hg 9 days after gene delivery. Human AM gene delivery enhanced renal function, as indicated by a 3-fold increase in renal blood flow and a 2-fold increase in glomerular filtration rate (n=5, P<0.05). Histological examination of the kidney revealed a significant reduction in glomerular sclerosis, tubular injury, luminol protein cast accumulation, and interstitial fibrosis as well as urinary protein. Human AM gene delivery caused significant decreases in left ventricular weight and cardiomyocyte diameter, which were accompanied by reduced interstitial fibrosis and extracellular matrix formation within the heart. Expression of human AM mRNA was detected in the kidney, adrenal gland, heart, aorta, lung, and liver; immunoreactive human AM levels were measured in urine and plasma. Significant increases in urinary and cardiac cAMP levels were observed in DOCA-salt rats receiving the human AM gene, indicating activation of the AM receptor. These findings showed that AM gene delivery attenuates hypertension, protects against cardiac remodeling and renal damage in volume-overload hypertension, and may have significance in therapeutic applications in cardiovascular and renal diseases.

Topics: Adenoviridae; Adrenomedullin; Animals; Cardiomegaly; Cyclic AMP; Cyclic GMP; Desoxycorticosterone; Disease Models, Animal; Fibrosis; Gene Transfer Techniques; Genetic Therapy; Genetic Vectors; Humans; Hypertension; Kidney Diseases; Male; Peptides; Rats; Rats, Sprague-Dawley; Systole