The soluble guanylate cyclase activator cinaciguat prevents cardiac dysfunction in a rat model of... more The soluble guanylate cyclase activator cinaciguat prevents cardiac dysfunction in a rat model of type-1 diabetes mellitus
Injection of 0.1 mg/kg zymosan in pigs i.v. elicited transient hemodynamic disturbance within min... more Injection of 0.1 mg/kg zymosan in pigs i.v. elicited transient hemodynamic disturbance within minutes, without major blood cell changes. In contrast, infusion of 1 mg/kg zymosan triggered maximal pulmonary hypertension with tachycardia, lasting for 30 min. This change was followed by a transient granulopenia with a trough at 1 h, and then, up to about 6 h, a major granulocytosis, resulting in a 3-4-fold increase of neutrophil-to-lymphocyte ratio (NLR). In parallel with the changes in WBC differential, qRT-PCR and ELISA analyses showed increased transcription and/or release of inflammatory cytokines and chemokines into blood, including IL-6, TNF-α, CCL-2, CXCL-10, and IL-1RA. The expression of IL-6 peaked at already 1.5-2.5 h, and we observed significant correlation between lymphopenia and IL-6 gene expression. While these changes are consistent with zymosan’s known stimulatory effect on both the humoral and cellular arms of the innate immune system, what gives novel clinical relevan...
Additional file 2: Figure S1. Time-course of body weight loss in diabetes mellitus. The graph sho... more Additional file 2: Figure S1. Time-course of body weight loss in diabetes mellitus. The graph shows the time-course of changes in body weight in vehicle-treated control (Co), cinaciguat-treated control (CoCin), vehicle-treated diabetic (DiabCo) and cinaciguat-treated diabetic (DiabCin) rats. Graph represent mean ± SEM, n = 9–11/group *P
Figure S1. (a) Representative picture of genotyping the TGF-β transgenic mice (samples 3,4 and 6 ... more Figure S1. (a) Representative picture of genotyping the TGF-β transgenic mice (samples 3,4 and 6 are transgenic, showing the 370 bp PCR product of the transgene; samples 1,2 and 5 are wild type controls). (b) Levels of circulating TGF-β1 in wild type B6 control mice (CTL) and transgenic mice (TGFβ) at the beginning of the study clearly shows that transgenic mice had 3-fold elevated plasma TGF-β1 levels (n = 14/group, p
Background. Genetic susceptibility to renal fibrosis may determine the individual rate of progres... more Background. Genetic susceptibility to renal fibrosis may determine the individual rate of progression to renal fail-ure. We aimed to study the progression in Rowett (RO) rats, a strain we found resistant to subtotal nephrectomy (SNX), comparing to Sprague–Dawley (SD) rats, a strain with established sensitivity in a radical ablation/infarction and diet-induced SNX model. Methods. Eight-week-old male RO (RO-SNX) and SD (SD-SNX, n = 5/group) rats underwent SNX and were kept on high protein and salt diet. Kidney function was moni-tored and the kidneys were evaluated by histology and im-munohistochemistry 5 weeks after SNX. Results. RO-SNX rats had only mild proteinuria and less glomerulosclerosis, accompanied by less fibronectin and TGF-β staining as compared to SD-SNX rats. Glomerular nitrotyrosine staining was less intense in RO-SNX vs SD-SNX, accompanied by less podocyte damage as demon-strated by desmin staining. Conclusion. Our results demonstrate the importance of podocyte damage ...
Peroxisome proliferator-activated receptor gamma (PPARγ) is a type II nuclear receptor, initially... more Peroxisome proliferator-activated receptor gamma (PPARγ) is a type II nuclear receptor, initially recognized in adipose tissue for its role in fatty acid storage and glucose metabolism. It promotes lipid uptake and adipogenesis by increasing insulin sensitivity and adiponectin release. Later, PPARγ was implicated in cardiac development and in critical conditions such as pulmonary arterial hypertension (PAH) and kidney failure. Recently, a cluster of different papers linked PPARγ signaling with another superfamily, the transforming growth factor beta (TGFβ), and its receptors, all of which play a major role in PAH and kidney failure. TGFβ is a multifunctional cytokine that drives inflammation, fibrosis, and cell differentiation while PPARγ activation reverses these adverse events in many models. Such opposite biological effects emphasize the delicate balance and complex crosstalk between PPARγ and TGFβ. Based on solid experimental and clinical evidence, the present review summarizes ...
A szív krónikus nyomásterhelése patológiás miokardiális hipertrófi a kifejlődéséhez vezet, amelyn... more A szív krónikus nyomásterhelése patológiás miokardiális hipertrófi a kifejlődéséhez vezet, amelynek kialakulását szakirodalmi adatok alapján a cGMP intracelluláris szintjének emelkedése sikeresen képes megakadályozni. Jelen kísérleteink során ezért a cGMP termeléséért felelős enzimet, a szolubilis guanilát-ciklázt aktiváló cinaciguat krónikus adagolásának hatásait vizsgáltuk nyomásindukált patológiás szívizom-hipertrófi a patkánymodelljén. A hasi aorta műtéti beszűkítésének (abdominális aortic banding, AAB) alkalmazásával hoztuk létre a bal kamra nyomásterhelését fi atal, hím Wistar-patkányokban; kontrollként sham operált állatokat használtunk. A kísérleti és kontrollcsoportok p.o. 10 mg/ kg/nap cinaciguat (Cin) vagy placebo (Co) kezelést kaptak hat héten keresztül. Nyomásterhelés hatására az AABCo-csoport állataiban a 6. hét végére szignifi káns mértékű patológiás miokardiális hipertrófi a fejlődött ki, amelyet emelkedett relatív szívtömeg, átlagos szívizomsejt-átmérő, kollagéntartalom és apoptózis jelenléte jellemzett. Cinaciguat alkalmazásával a vérnyomás szignifi káns változtatása nélkül csökkenthető volt e hipertrófi ára jellemző valamennyi morfológiai elváltozás, továbbá az AAB hatására a kardiális funkcióban, így a kontraktilitásban megfi gyelhető eltérések kialakulása is elmaradt a kezelt csoportban. Eredményeink alapján az sGC krónikus aktiválásával felerősített cGMP-jelátvitel hatékony, új stratégia lehet a patológiás miokardiális hipertrófi a kifejlődésének prevenciójában. Cinaciguat prevents the development of pathologic hypertrophy in a rat model of left ventricular pressure overload Pathologic myocardial hypertrophy develops when the heart is chronically pressure-overloaded. Elevated intracellular cGMP-levels have been reported to prevent the development of pathologic myocardial hypertrophy, therefore we investigated the effects of chronic activation of the cGMP producing enzyme, soluble guanylate cyclase by Cinaciguat in a rat model of pressure overload-induced cardiac hypertrophy. Abdominal aortic banding (AAB) was used to evoke pressure overload-induced cardiac hypertrophy in male Wistar rats. Sham operated animals served as controls. Experimental and control groups were treated with 10 mg/kg/day Cinaciguat (Cin) or placebo (Co) p.o. for six weeks, respectively. Pathologic myocardial hypertrophy was present in the AABCo group following 6 weeks of pressure overload of the heart, evidenced by increased relative heart weight, average cardiomyocyte diameter, collagen content and apoptosis. Cinaciguat did not signifi cantly alter blood pressure, but effectively attenuated all features of pathologic myocardial hypertrophy, and normalized functional changes, such as the increase in contractility following AAB. Our results demonstrate that chronic enhancement of cGMP signaling by pharmacological activation of sGC might be a novel therapeutic approach in the prevention of pathologic myocardial hypertrophy.
A cukorbetegség diabéteszes cardiomyopathia kialakulásához vezet, amely károsodott nitrogén-monox... more A cukorbetegség diabéteszes cardiomyopathia kialakulásához vezet, amely károsodott nitrogén-monoxid (NO)-szolubilis guanilát-cikláz (sGC)-ciklikus guanozin-monofoszfát (cGMP) jelátvitellel társul. A megnövelt intracelluláris cGMP-szint kardioprotektív hatását több szívbetegségben is leírták. Jelen kísérletünkben az sGC farmakológiai aktivációjának hatását vizsgáltuk diabéteszes cardiomyopathiában. Módszerek: Patkányainkban 1-es típusú diabetes mellitust (DM) streptozotocinnal indukáltunk. Ezt követően az állatok per os sGC-aktivátor cinaciguatot (10 mg/testtömeg kg/nap) vagy placebót kaptak 8 héten át. A kardiális funkció megítélésére bal kamrai (BK) nyomástérfogat (P-V) analízist végeztünk. Gén-(qRT-PCR) és proteinexpressziós (Western-blot) vizsgálatokat hajtottunk végre BK-i szívizomszövetből. A myocardium strukturális változását, fi brotikus átépülésének jeleit és a DNS-károsodás mértékét szövettani-és immunhisztokémiai vizsgálatokkal tanulmányoztuk. Eredmények: Cukorbetegségben károsodott miokardiális cGMP-jelátvitelt láttunk (emelkedett foszfodiészteráz-5 expresszió, csökkent cGMP-szint és protein-kináz-G aktivitás). Emellett szívizomsejt-hipertrófi a, fi brotikus átépülés és DNS-töredezettség volt jelen a BK-ban, ami romlott kontraktilitással és diasztolés diszfunkcióval párosult. A cinaciguat kezelés hatásosnak bizonyult a DM indukálta molekuláris és szövettani eltérések megelőzésében, továbbá szignifi kánsan javította a szisztolés és a diasztolés funkciót DM-ben. Következtetések: A cinaciguat megelőzte a diabéteszes szív strukturális és molekuláris változásait, illetve javította annak pumpafunkcióját. Mindezek alapján az sGC farmakológiai aktivációja új terápiás megközelítést képviselhet a diabéteszes cardiomyopathia kezelésében. The soluble guanylate cyclase activator cinaciguat prevents cardiac dysfunction in a rat model of type-1 diabetes mellitus Introduction: Diabetes mellitus (DM) leads to the development of diabetic cardiomyopathy, which is associated with altered nitric oxide (NO)-soluble guanylate cyclase (sGC)-cyclic guanosine monophosphate (cGMP) signaling. Cardio-protective effects of elevated intracellular cGMP-levels have been described in different heart diseases. In the current study we aimed at investigating the effects of pharmacological activation of sGC in diabetic cardiomyopathy. Methods: Type-1 DM was induced in rats by streptozotocin. Animals were treated either with the sGC activator cinaciguat (10 mg/kg/day) or with placebo orally for 8 weeks. Left ventricular (LV) pressure-volume (P-V) analysis was used to assess cardiac performance. Additionally, gene expression (qRT-PCR) and protein expression analysis (Western blot) were performed. Cardiac structure, markers of fi brotic remodelling and DNA damage were examined by histology, immunohistochemistry and TUNEL assay, respectively. Results: DM was associated with deteriorated cGMP signalling in the myocardium (elevated phosphodiesterase-5 expression, lower cGMP-level and impaired PKG activity). Cardiomyocyte hypertrophy, fi brotic remodeling and DNA fragmentation were present in DM that was associated with impaired LV contractility and diastolic function. Cinaciguat treatment effectively prevented DM related molecular, histological alterations and signifi cantly improved systolic and diastolic function. Conclusions: Cinaciguat prevented structural, molecular alterations and improved cardiac performance of the diabetic heart. Pharmacological activation of sGC might represent a new therapy approach for diabetic cardiomyopathy. *A szerzők a munkához egyenlő mértékben járultak hozzá.
Current Opinion in Nephrology and Hypertension, 2019
Purpose of review Pulmonary arterial hypertension (PAH) is characterized by pulmonary arterial en... more Purpose of review Pulmonary arterial hypertension (PAH) is characterized by pulmonary arterial endothelial cell (PAEC) dysfunction and apoptosis, pulmonary arterial smooth muscle cell (PASMC) proliferation, inflammation, vasoconstriction, and metabolic disturbances that include disrupted bone morphogenetic protein receptor (BMPR2)-peroxisome proliferator-activated receptor gamma (PPARg) axis and DNA damage. Activation of PPARg improves many of these mechanisms, although erroneous reports on potential adverse effects of thiazolidinedione (TZD)-class PPARg agonists reduced their clinical use in the past decade. Here, we review recent findings in heart, lung, and kidney research related to the pathobiology of vascular remodeling and tissue fibrosis, and also potential therapeutic effects of the PPARg agonist pioglitazone. Recent findings Independent of its metabolic effects (improved insulin sensitivity and fatty acid handling), PPARg activation rescues BMPR2 dysfunction, inhibits TGFb/Smad3/CTGF and TGFb/pSTAT3/pFoxO1 pathways, and induces the PPARg/apoE axis, inhibiting vascular remodeling. PPARg activation dampens mtDNA damage via PPARg/UBR5/ATM pathway, improves function of endothelial progenitor cells (EPCs), and decrease renal fibrosis by repressing TGFb/pSTAT3 and TGFb/EGR1.
Background: It has been proposed that peroxisome proliferator-activated receptor-γ (PPARγ) agonis... more Background: It has been proposed that peroxisome proliferator-activated receptor-γ (PPARγ) agonists might reduce renal fibrosis, however, several studies had contradictory results. Moreover, the possible interaction of TGF-β 1 , PPARγ, and transcription factors in renal fibrosis have not been investigated. We hypothesized that oral pioglitazone treatment would inhibit TGF-β-driven renal fibrosis and its progression, by modulating profibrotic transcription factors in TGF-β 1 transgenic mice. Methods: Male C57Bl/6 J mice (control, CTL, n = 14) and TGF-β overexpressing transgenic mice (TGFβ, n = 14, having elevated plasma TGF-β 1 level) were divided in two sets at 10 weeks of age. Mice in the first set were fed with regular rodent chow (CTL and TGFβ, n = 7/group). Mice in the second set were fed with chow containing pioglitazone (at a dose of 20 mg/kg/day, CTL + Pio and TGFβ+Pio, n = 7/group). After 5 weeks of treatment, blood pressure was assessed and urine samples were collected, and the kidneys were analyzed for histology, mRNA and protein expression. Results: TGF-β 1 induced glomerulosclerosis and tubulointerstitial damage were significantly reduced by pioglitazone. Pioglitazone inhibited renal mRNA expression of all the profibrotic effectors: type-III collagen, TGF-β 1 , CTGF and TIMP-1, and alike transcription factors cFos/cJun and protein expression of EGR-1, and STAT3 protein phosphorylation. Conclusions: Oral administration of PPARγ agonist pioglitazone significantly reduces TGF-β 1-driven renal fibrosis, via the attenuation of EGR-1, STAT3 and AP-1. This implies that PPARγ agonists might be effective in the treatment of chronic kidney disease patients.
While heart transplantation (HTX) is the definitive therapy of heart failure, donor shortage is e... more While heart transplantation (HTX) is the definitive therapy of heart failure, donor shortage is emerging. Pharmacological activation of soluble guanylate cyclase (sGC) and increased cGMP-signalling have been reported to have cardioprotective properties. Gemfibrozil has recently been shown to exert sGC activating effects in vitro. We aimed to investigate whether pharmacological preconditioning of donor hearts with gemfibrozil could protect against ischemia/reperfusion injury and preserve myocardial function in a heterotopic rat HTX model. Donor Lewis rats received p.o. gemfibrozil (150 mg/kg body weight) or vehicle for 2 days. The hearts were explanted, stored for 1 h in cold preservation solution, and heterotopically transplanted. 1 h after starting reperfusion, left ventricular (LV) pressure-volume relations and coronary blood flow (CBF) were assessed to evaluate early post-transplant graft function. After 1 h reperfusion, LV contractility, active relaxation and CBF were significan...
Background: Although TGF-ß and the transcription factor Egr-1 play an important role in both kidn... more Background: Although TGF-ß and the transcription factor Egr-1 play an important role in both kidney fibrosis and in response to acute changes of renal medullary osmolarity, their role under sustained hypo-or hyperosmolar conditions has not been elucidated. We investigated the effects of chronic hypertonicity and hypotonicity on the renal medullary TGF-ß and Egr-1 expression. Methods: Male adult Sprague Dawley rats (n = 6/group) were treated with 15 mg/day furosemide, or the rats were water restricted to 15 ml/200 g body weight per day. Control rats had free access to water and rodent chow. Kidneys were harvested after 5 days of treament. In cultured inner medullary collecting duct (IMCD) cells, osmolarity was increased from 330 mOsm to 900 mOsm over 6 days. Analyses were performed at 330, 600 and 900 mOsm. Results: Urine osmolarity has not changed due to furosemide treatment but increased 2-fold after water restriction (p < 0.05). Gene expression of TGF-ß and Egr-1 increased by 1.9-fold and 7-fold in the hypertonic medulla, respectively (p < 0.05), accompanied by 6-fold and 2-fold increased c-Fos and TIMP-1 expression, respectively (p < 0.05) and positive immunostaining for TGF-ß and Egr-1 (p < 0.05). Similarly, hyperosmolarity led to overexpression of TGF-ß and Egr-1 mRNA in IMCD cells (2.5-fold and 3.5-fold increase from 330 to 900 mOsm, respectively (p < 0.05)) accompanied by significant c-Fos and c-Jun overexpressions (p < 0.01), and increased Col3a1 and Col4a1 mRNA expression. Conclusion: We conclude that both TGF-ß and Egr-1 are upregulated by sustained hyperosmolarity in the rat renal medulla, and it favors the expression of extracellular matrix components.
Background/Aims: Diabetic nephropathy remains a major clinical problem. The effects of prorenin m... more Background/Aims: Diabetic nephropathy remains a major clinical problem. The effects of prorenin might be adverse, but the literature data are controversial. We compared the renal effects of the (pro)renin receptor ((P)RR) blockade and angiotensin converting enzyme (ACE) inhibition on the progression of diabetic nephropathy in rats. Methods: Diabetes (DM) was induced by ip. streptozotocin administration in adult male Sprague-Dawley rats, followed by eight weeks of treatment with the (P)RR blocker „handle region” decoy peptide (HRP, 0,1 mg/kg/day) or with the ACE inhibitor Quinapril (Q, 50 mg/kg/day) and grouped as follows: 1. Control (n=10); 2. DM (n=8); 3. DM+HRP (n=6); 4. DM+Q (n=10); 5. DM+Q+HRP (n=10). Renal functional parameters, histology and gene expressions were evaluated. Results: HRP reduced glomerulosclerosis and podocyte desmin expression, but did not affect proteinuria and tubular ERK(1/2) phosphorylation. Both Q and Q+HRP treatment reduced proteinuria, glomerular and tu...
The soluble guanylate cyclase activator cinaciguat prevents cardiac dysfunction in a rat model of... more The soluble guanylate cyclase activator cinaciguat prevents cardiac dysfunction in a rat model of type-1 diabetes mellitus
Injection of 0.1 mg/kg zymosan in pigs i.v. elicited transient hemodynamic disturbance within min... more Injection of 0.1 mg/kg zymosan in pigs i.v. elicited transient hemodynamic disturbance within minutes, without major blood cell changes. In contrast, infusion of 1 mg/kg zymosan triggered maximal pulmonary hypertension with tachycardia, lasting for 30 min. This change was followed by a transient granulopenia with a trough at 1 h, and then, up to about 6 h, a major granulocytosis, resulting in a 3-4-fold increase of neutrophil-to-lymphocyte ratio (NLR). In parallel with the changes in WBC differential, qRT-PCR and ELISA analyses showed increased transcription and/or release of inflammatory cytokines and chemokines into blood, including IL-6, TNF-α, CCL-2, CXCL-10, and IL-1RA. The expression of IL-6 peaked at already 1.5-2.5 h, and we observed significant correlation between lymphopenia and IL-6 gene expression. While these changes are consistent with zymosan’s known stimulatory effect on both the humoral and cellular arms of the innate immune system, what gives novel clinical relevan...
Additional file 2: Figure S1. Time-course of body weight loss in diabetes mellitus. The graph sho... more Additional file 2: Figure S1. Time-course of body weight loss in diabetes mellitus. The graph shows the time-course of changes in body weight in vehicle-treated control (Co), cinaciguat-treated control (CoCin), vehicle-treated diabetic (DiabCo) and cinaciguat-treated diabetic (DiabCin) rats. Graph represent mean ± SEM, n = 9–11/group *P
Figure S1. (a) Representative picture of genotyping the TGF-β transgenic mice (samples 3,4 and 6 ... more Figure S1. (a) Representative picture of genotyping the TGF-β transgenic mice (samples 3,4 and 6 are transgenic, showing the 370 bp PCR product of the transgene; samples 1,2 and 5 are wild type controls). (b) Levels of circulating TGF-β1 in wild type B6 control mice (CTL) and transgenic mice (TGFβ) at the beginning of the study clearly shows that transgenic mice had 3-fold elevated plasma TGF-β1 levels (n = 14/group, p
Background. Genetic susceptibility to renal fibrosis may determine the individual rate of progres... more Background. Genetic susceptibility to renal fibrosis may determine the individual rate of progression to renal fail-ure. We aimed to study the progression in Rowett (RO) rats, a strain we found resistant to subtotal nephrectomy (SNX), comparing to Sprague–Dawley (SD) rats, a strain with established sensitivity in a radical ablation/infarction and diet-induced SNX model. Methods. Eight-week-old male RO (RO-SNX) and SD (SD-SNX, n = 5/group) rats underwent SNX and were kept on high protein and salt diet. Kidney function was moni-tored and the kidneys were evaluated by histology and im-munohistochemistry 5 weeks after SNX. Results. RO-SNX rats had only mild proteinuria and less glomerulosclerosis, accompanied by less fibronectin and TGF-β staining as compared to SD-SNX rats. Glomerular nitrotyrosine staining was less intense in RO-SNX vs SD-SNX, accompanied by less podocyte damage as demon-strated by desmin staining. Conclusion. Our results demonstrate the importance of podocyte damage ...
Peroxisome proliferator-activated receptor gamma (PPARγ) is a type II nuclear receptor, initially... more Peroxisome proliferator-activated receptor gamma (PPARγ) is a type II nuclear receptor, initially recognized in adipose tissue for its role in fatty acid storage and glucose metabolism. It promotes lipid uptake and adipogenesis by increasing insulin sensitivity and adiponectin release. Later, PPARγ was implicated in cardiac development and in critical conditions such as pulmonary arterial hypertension (PAH) and kidney failure. Recently, a cluster of different papers linked PPARγ signaling with another superfamily, the transforming growth factor beta (TGFβ), and its receptors, all of which play a major role in PAH and kidney failure. TGFβ is a multifunctional cytokine that drives inflammation, fibrosis, and cell differentiation while PPARγ activation reverses these adverse events in many models. Such opposite biological effects emphasize the delicate balance and complex crosstalk between PPARγ and TGFβ. Based on solid experimental and clinical evidence, the present review summarizes ...
A szív krónikus nyomásterhelése patológiás miokardiális hipertrófi a kifejlődéséhez vezet, amelyn... more A szív krónikus nyomásterhelése patológiás miokardiális hipertrófi a kifejlődéséhez vezet, amelynek kialakulását szakirodalmi adatok alapján a cGMP intracelluláris szintjének emelkedése sikeresen képes megakadályozni. Jelen kísérleteink során ezért a cGMP termeléséért felelős enzimet, a szolubilis guanilát-ciklázt aktiváló cinaciguat krónikus adagolásának hatásait vizsgáltuk nyomásindukált patológiás szívizom-hipertrófi a patkánymodelljén. A hasi aorta műtéti beszűkítésének (abdominális aortic banding, AAB) alkalmazásával hoztuk létre a bal kamra nyomásterhelését fi atal, hím Wistar-patkányokban; kontrollként sham operált állatokat használtunk. A kísérleti és kontrollcsoportok p.o. 10 mg/ kg/nap cinaciguat (Cin) vagy placebo (Co) kezelést kaptak hat héten keresztül. Nyomásterhelés hatására az AABCo-csoport állataiban a 6. hét végére szignifi káns mértékű patológiás miokardiális hipertrófi a fejlődött ki, amelyet emelkedett relatív szívtömeg, átlagos szívizomsejt-átmérő, kollagéntartalom és apoptózis jelenléte jellemzett. Cinaciguat alkalmazásával a vérnyomás szignifi káns változtatása nélkül csökkenthető volt e hipertrófi ára jellemző valamennyi morfológiai elváltozás, továbbá az AAB hatására a kardiális funkcióban, így a kontraktilitásban megfi gyelhető eltérések kialakulása is elmaradt a kezelt csoportban. Eredményeink alapján az sGC krónikus aktiválásával felerősített cGMP-jelátvitel hatékony, új stratégia lehet a patológiás miokardiális hipertrófi a kifejlődésének prevenciójában. Cinaciguat prevents the development of pathologic hypertrophy in a rat model of left ventricular pressure overload Pathologic myocardial hypertrophy develops when the heart is chronically pressure-overloaded. Elevated intracellular cGMP-levels have been reported to prevent the development of pathologic myocardial hypertrophy, therefore we investigated the effects of chronic activation of the cGMP producing enzyme, soluble guanylate cyclase by Cinaciguat in a rat model of pressure overload-induced cardiac hypertrophy. Abdominal aortic banding (AAB) was used to evoke pressure overload-induced cardiac hypertrophy in male Wistar rats. Sham operated animals served as controls. Experimental and control groups were treated with 10 mg/kg/day Cinaciguat (Cin) or placebo (Co) p.o. for six weeks, respectively. Pathologic myocardial hypertrophy was present in the AABCo group following 6 weeks of pressure overload of the heart, evidenced by increased relative heart weight, average cardiomyocyte diameter, collagen content and apoptosis. Cinaciguat did not signifi cantly alter blood pressure, but effectively attenuated all features of pathologic myocardial hypertrophy, and normalized functional changes, such as the increase in contractility following AAB. Our results demonstrate that chronic enhancement of cGMP signaling by pharmacological activation of sGC might be a novel therapeutic approach in the prevention of pathologic myocardial hypertrophy.
A cukorbetegség diabéteszes cardiomyopathia kialakulásához vezet, amely károsodott nitrogén-monox... more A cukorbetegség diabéteszes cardiomyopathia kialakulásához vezet, amely károsodott nitrogén-monoxid (NO)-szolubilis guanilát-cikláz (sGC)-ciklikus guanozin-monofoszfát (cGMP) jelátvitellel társul. A megnövelt intracelluláris cGMP-szint kardioprotektív hatását több szívbetegségben is leírták. Jelen kísérletünkben az sGC farmakológiai aktivációjának hatását vizsgáltuk diabéteszes cardiomyopathiában. Módszerek: Patkányainkban 1-es típusú diabetes mellitust (DM) streptozotocinnal indukáltunk. Ezt követően az állatok per os sGC-aktivátor cinaciguatot (10 mg/testtömeg kg/nap) vagy placebót kaptak 8 héten át. A kardiális funkció megítélésére bal kamrai (BK) nyomástérfogat (P-V) analízist végeztünk. Gén-(qRT-PCR) és proteinexpressziós (Western-blot) vizsgálatokat hajtottunk végre BK-i szívizomszövetből. A myocardium strukturális változását, fi brotikus átépülésének jeleit és a DNS-károsodás mértékét szövettani-és immunhisztokémiai vizsgálatokkal tanulmányoztuk. Eredmények: Cukorbetegségben károsodott miokardiális cGMP-jelátvitelt láttunk (emelkedett foszfodiészteráz-5 expresszió, csökkent cGMP-szint és protein-kináz-G aktivitás). Emellett szívizomsejt-hipertrófi a, fi brotikus átépülés és DNS-töredezettség volt jelen a BK-ban, ami romlott kontraktilitással és diasztolés diszfunkcióval párosult. A cinaciguat kezelés hatásosnak bizonyult a DM indukálta molekuláris és szövettani eltérések megelőzésében, továbbá szignifi kánsan javította a szisztolés és a diasztolés funkciót DM-ben. Következtetések: A cinaciguat megelőzte a diabéteszes szív strukturális és molekuláris változásait, illetve javította annak pumpafunkcióját. Mindezek alapján az sGC farmakológiai aktivációja új terápiás megközelítést képviselhet a diabéteszes cardiomyopathia kezelésében. The soluble guanylate cyclase activator cinaciguat prevents cardiac dysfunction in a rat model of type-1 diabetes mellitus Introduction: Diabetes mellitus (DM) leads to the development of diabetic cardiomyopathy, which is associated with altered nitric oxide (NO)-soluble guanylate cyclase (sGC)-cyclic guanosine monophosphate (cGMP) signaling. Cardio-protective effects of elevated intracellular cGMP-levels have been described in different heart diseases. In the current study we aimed at investigating the effects of pharmacological activation of sGC in diabetic cardiomyopathy. Methods: Type-1 DM was induced in rats by streptozotocin. Animals were treated either with the sGC activator cinaciguat (10 mg/kg/day) or with placebo orally for 8 weeks. Left ventricular (LV) pressure-volume (P-V) analysis was used to assess cardiac performance. Additionally, gene expression (qRT-PCR) and protein expression analysis (Western blot) were performed. Cardiac structure, markers of fi brotic remodelling and DNA damage were examined by histology, immunohistochemistry and TUNEL assay, respectively. Results: DM was associated with deteriorated cGMP signalling in the myocardium (elevated phosphodiesterase-5 expression, lower cGMP-level and impaired PKG activity). Cardiomyocyte hypertrophy, fi brotic remodeling and DNA fragmentation were present in DM that was associated with impaired LV contractility and diastolic function. Cinaciguat treatment effectively prevented DM related molecular, histological alterations and signifi cantly improved systolic and diastolic function. Conclusions: Cinaciguat prevented structural, molecular alterations and improved cardiac performance of the diabetic heart. Pharmacological activation of sGC might represent a new therapy approach for diabetic cardiomyopathy. *A szerzők a munkához egyenlő mértékben járultak hozzá.
Current Opinion in Nephrology and Hypertension, 2019
Purpose of review Pulmonary arterial hypertension (PAH) is characterized by pulmonary arterial en... more Purpose of review Pulmonary arterial hypertension (PAH) is characterized by pulmonary arterial endothelial cell (PAEC) dysfunction and apoptosis, pulmonary arterial smooth muscle cell (PASMC) proliferation, inflammation, vasoconstriction, and metabolic disturbances that include disrupted bone morphogenetic protein receptor (BMPR2)-peroxisome proliferator-activated receptor gamma (PPARg) axis and DNA damage. Activation of PPARg improves many of these mechanisms, although erroneous reports on potential adverse effects of thiazolidinedione (TZD)-class PPARg agonists reduced their clinical use in the past decade. Here, we review recent findings in heart, lung, and kidney research related to the pathobiology of vascular remodeling and tissue fibrosis, and also potential therapeutic effects of the PPARg agonist pioglitazone. Recent findings Independent of its metabolic effects (improved insulin sensitivity and fatty acid handling), PPARg activation rescues BMPR2 dysfunction, inhibits TGFb/Smad3/CTGF and TGFb/pSTAT3/pFoxO1 pathways, and induces the PPARg/apoE axis, inhibiting vascular remodeling. PPARg activation dampens mtDNA damage via PPARg/UBR5/ATM pathway, improves function of endothelial progenitor cells (EPCs), and decrease renal fibrosis by repressing TGFb/pSTAT3 and TGFb/EGR1.
Background: It has been proposed that peroxisome proliferator-activated receptor-γ (PPARγ) agonis... more Background: It has been proposed that peroxisome proliferator-activated receptor-γ (PPARγ) agonists might reduce renal fibrosis, however, several studies had contradictory results. Moreover, the possible interaction of TGF-β 1 , PPARγ, and transcription factors in renal fibrosis have not been investigated. We hypothesized that oral pioglitazone treatment would inhibit TGF-β-driven renal fibrosis and its progression, by modulating profibrotic transcription factors in TGF-β 1 transgenic mice. Methods: Male C57Bl/6 J mice (control, CTL, n = 14) and TGF-β overexpressing transgenic mice (TGFβ, n = 14, having elevated plasma TGF-β 1 level) were divided in two sets at 10 weeks of age. Mice in the first set were fed with regular rodent chow (CTL and TGFβ, n = 7/group). Mice in the second set were fed with chow containing pioglitazone (at a dose of 20 mg/kg/day, CTL + Pio and TGFβ+Pio, n = 7/group). After 5 weeks of treatment, blood pressure was assessed and urine samples were collected, and the kidneys were analyzed for histology, mRNA and protein expression. Results: TGF-β 1 induced glomerulosclerosis and tubulointerstitial damage were significantly reduced by pioglitazone. Pioglitazone inhibited renal mRNA expression of all the profibrotic effectors: type-III collagen, TGF-β 1 , CTGF and TIMP-1, and alike transcription factors cFos/cJun and protein expression of EGR-1, and STAT3 protein phosphorylation. Conclusions: Oral administration of PPARγ agonist pioglitazone significantly reduces TGF-β 1-driven renal fibrosis, via the attenuation of EGR-1, STAT3 and AP-1. This implies that PPARγ agonists might be effective in the treatment of chronic kidney disease patients.
While heart transplantation (HTX) is the definitive therapy of heart failure, donor shortage is e... more While heart transplantation (HTX) is the definitive therapy of heart failure, donor shortage is emerging. Pharmacological activation of soluble guanylate cyclase (sGC) and increased cGMP-signalling have been reported to have cardioprotective properties. Gemfibrozil has recently been shown to exert sGC activating effects in vitro. We aimed to investigate whether pharmacological preconditioning of donor hearts with gemfibrozil could protect against ischemia/reperfusion injury and preserve myocardial function in a heterotopic rat HTX model. Donor Lewis rats received p.o. gemfibrozil (150 mg/kg body weight) or vehicle for 2 days. The hearts were explanted, stored for 1 h in cold preservation solution, and heterotopically transplanted. 1 h after starting reperfusion, left ventricular (LV) pressure-volume relations and coronary blood flow (CBF) were assessed to evaluate early post-transplant graft function. After 1 h reperfusion, LV contractility, active relaxation and CBF were significan...
Background: Although TGF-ß and the transcription factor Egr-1 play an important role in both kidn... more Background: Although TGF-ß and the transcription factor Egr-1 play an important role in both kidney fibrosis and in response to acute changes of renal medullary osmolarity, their role under sustained hypo-or hyperosmolar conditions has not been elucidated. We investigated the effects of chronic hypertonicity and hypotonicity on the renal medullary TGF-ß and Egr-1 expression. Methods: Male adult Sprague Dawley rats (n = 6/group) were treated with 15 mg/day furosemide, or the rats were water restricted to 15 ml/200 g body weight per day. Control rats had free access to water and rodent chow. Kidneys were harvested after 5 days of treament. In cultured inner medullary collecting duct (IMCD) cells, osmolarity was increased from 330 mOsm to 900 mOsm over 6 days. Analyses were performed at 330, 600 and 900 mOsm. Results: Urine osmolarity has not changed due to furosemide treatment but increased 2-fold after water restriction (p < 0.05). Gene expression of TGF-ß and Egr-1 increased by 1.9-fold and 7-fold in the hypertonic medulla, respectively (p < 0.05), accompanied by 6-fold and 2-fold increased c-Fos and TIMP-1 expression, respectively (p < 0.05) and positive immunostaining for TGF-ß and Egr-1 (p < 0.05). Similarly, hyperosmolarity led to overexpression of TGF-ß and Egr-1 mRNA in IMCD cells (2.5-fold and 3.5-fold increase from 330 to 900 mOsm, respectively (p < 0.05)) accompanied by significant c-Fos and c-Jun overexpressions (p < 0.01), and increased Col3a1 and Col4a1 mRNA expression. Conclusion: We conclude that both TGF-ß and Egr-1 are upregulated by sustained hyperosmolarity in the rat renal medulla, and it favors the expression of extracellular matrix components.
Background/Aims: Diabetic nephropathy remains a major clinical problem. The effects of prorenin m... more Background/Aims: Diabetic nephropathy remains a major clinical problem. The effects of prorenin might be adverse, but the literature data are controversial. We compared the renal effects of the (pro)renin receptor ((P)RR) blockade and angiotensin converting enzyme (ACE) inhibition on the progression of diabetic nephropathy in rats. Methods: Diabetes (DM) was induced by ip. streptozotocin administration in adult male Sprague-Dawley rats, followed by eight weeks of treatment with the (P)RR blocker „handle region” decoy peptide (HRP, 0,1 mg/kg/day) or with the ACE inhibitor Quinapril (Q, 50 mg/kg/day) and grouped as follows: 1. Control (n=10); 2. DM (n=8); 3. DM+HRP (n=6); 4. DM+Q (n=10); 5. DM+Q+HRP (n=10). Renal functional parameters, histology and gene expressions were evaluated. Results: HRP reduced glomerulosclerosis and podocyte desmin expression, but did not affect proteinuria and tubular ERK(1/2) phosphorylation. Both Q and Q+HRP treatment reduced proteinuria, glomerular and tu...
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Papers by Gábor Kökény