Inhibition of both NOX and TNF-α exerts substantial renoprotective effects in renal ischemia reperfusion injury rat model.

BACKGROUND AND AIMS: Acute kidney injury (AKI) due to renal ischemia-reperfusion injury (RIRI) is associated with high morbidity and mortality, with no renoprotective drug available. Previous research focused on single drug targets, yet this approach has not reached translational success. Given the complexity of this condition, we aimed to identify a disease module and apply a multitarget network pharmacology approach. METHODS: Identification of a disease module with potential drug targets was performed utilizing Disease Module Detection algorithm using NADPH oxidases (NOXs) as seeds. We then assessed the protective effect of a multitarget network pharmacology targeting the identified module in a rat model of RIRI. Rats were divided into five groups; sham, RIRI, and RIRI treated with setanaxib (NOX inhibitor, 10 mg/kg), etanercept (TNF-α inhibitor, 10 mg/kg), and setanaxib and etanercept (5 mg/kg each). Kidney functions, histopathological changes and oxidative stress markers (MDA and reduced GSH) were assessed. Immunohistochemistry of inflammatory (TNF-α, NF-κB) apoptotic (cCasp-3, Bax/Bcl 2), fibrotic (α-SMA) and proteolysis (MMP-9) markers was performed. RESULTS: Our in-silico analysis yielded a disease module with TNF receptor 1 (TNFR1A) as the closest target to both NOX1 and NOX2. Targeting this module by a low-dose combination of setanaxib, and etanercept, resulted in a synergistic effect and ameliorated ischemic AKI in rats. This was evidenced by improved kidney function and reduced expression of inflammatory, apoptotic, proteolytic and fibrotic markers. CONCLUSIONS: Our findings show that applying a multitarget network pharmacology approach allows synergistic renoprotective effect in ischemic AKI and might pave the way towards translational success.

Hepatic ß-arrestins: potential roles in liver health and disease.

Β-arrestins are intracellular scaffolding proteins that have multifaceted roles in different types of disorders. In this review article, we gave a summary about the discovery, characterization and classification of these proteins and their intracellular functions. Moreover, this review article focused on the hepatic expression of ß-arrestins and their hepatocellular distribution and function in each liver cell type. Also, we showed that ß-arrestins are key regulators of distinct types of hepatic disorders. On the other hand, we addressed some important points that have never been studied before regarding the role of ß-arrestins in certain types of hepatic disorders which needs more research efforts to cover.

Acute and chronic metabolic effects of carvedilol in high-fructose, high-fat diet-fed mice: implication of ß-arrestin2 pathway.

We aimed to investigate the acute and chronic effects of carvedilol on insulin resistance in high-fructose, high-fat diet (HFrHFD) - fed mice and the implication of the ß-arrestin2 pathway. The acute effect of carvedilol (10 mg/kg, i.p.) on glucose tolerance and hepatic lipid signaling in normal and insulin resistant mice was investigated. Then, the chronic effect of carvedilol on insulin resistance and dyslipidemia in HFrHFD-fed mice was examined. Changes in ß-arrestin2 and its downstream signals in liver, skeletal muscle, and adipose tissue were measured. This involved measuring phosphatidylinositol 4,5-bisphosphate (PIP2) and diacylglycerol (DAG) levels and protein kinase B (AKT) activity. Carvedilol acutely reduced fasting blood glucose levels in both normal and insulin resistant mice without significantly affecting the glucose tolerance. These acute effects were associated with increased hepatic PIP2 but decreased hepatic DAG levels. Chronic administration of carvedilol significantly ameliorated insulin resistance and dyslipidemia in HFrHFD-fed mice. These chronic effects were associated with increased ß-arrestin2, PIP2, and AKT activity levels but decreased DAG levels in the classical insulin target tissues. In conclusion, carvedilol acutely maintains glucose homeostasis and chronically ameliorates insulin resistance and dyslipidemia in HFrHFD-fed mice. The insulin sensitizing effects of carvedilol are highly correlated with the upregulation of ß-arrestin2 pathway.

Carvedilol Diminishes Cardiac Remodeling Induced by High-Fructose/High-Fat Diet in Mice via Enhancing Cardiac ß-Arrestin2 Signaling.

BACKGROUND: Insulin resistance (IR) is a well-known risk factor for cardiovascular complications. This study aimed to investigate the effect of a dietary model of IR in mice on cardiac remodeling, cardiac ß-arrestin2 signaling, and the protective effects of carvedilol as a ß-arrestin-biased agonist. METHODS AND RESULTS: Insulin resistance was induced by feeding mice high-fructose/high-fat diet (HFrHFD) for 16 weeks. Carvedilol was adiministered for 4 weeks starting at week 13. At the end of the experiment, body weight, heart weight, left and right ventricular thickness, visceral fat weight, fasting blood glucose (FBG), serum insulin, IR index, and serum endothelin-1 were measured. In addition, cardiac tissue samples were histopathologically examined. Also, cardiac levels of cardiotrophin-1, ß-arrestin2, phosphatidylinositol 4,5 bisphosphate (PIP2), diacylglycerol (DAG), and phosphoserine 473 Akt (pS473 Akt) were measured. Results showed significant increases in the FBG, serum insulin, IR index, serum endothelin-1, cardiac DAG, cardiac fibrosis, and degenerated cardiac myofibrils in HFrHFD-fed mice associated with a significant reduction in cardiac levels of cardiotrophin-1, ß-arrestin2, PIP2, and pS473 Akt. On the other hand, carvedilol significantly reduced the heart weight, FBG, serum insulin, IR index, serum endothelin-1, cardiac DAG, left ventricular thickness, right ventricular fibrosis, and degeneration of cardiac myofibrils. In addition, carvedilol significantly increased cardiac levels of cardiotrophin-1, ß-arrestin2, PIP2, and pS473 Akt. CONCLUSION: Carvedilol enhances cardiac ß-arrestin2 signaling and reduces cardiac remodeling in HFrHFD-fed mice.

Effect of imidazoline-1 receptor agonists on renal dysfunction in rats associated with chronic, sequential fructose and ethanol administration.

Insulin resistance and chronic alcoholism are risk factors for renal dysfunction. This study investigated the therapeutic effects of two imidazoline-1 receptor (I1R) agonists on renal dysfunction in rats after chronic, sequential fructose and ethanol administration. Daily drinking water was supplemented with fructose (10%, w/v) for 12 weeks and then with ethanol (20%, v/v) for another 8 weeks. Rats were treated with rilmenidine and clonidine in the last two weeks of the study. Blood glucose and serum insulin (sIns) levels, lipid profiles, kidney function and renal histopathology were evaluated at the end of the experiment. Additionally, renal gene expression of nischarin, phosphatidylcholine-specific phospholipase C (PC-PLC) and prostaglandin E2 (PGE2) were measured. Renal levels of superoxide dismutase (SOD), malondialdehyde (MDA), myeloperoxidase (MPO), inducible nitric oxide synthase (iNOS) and total NO (tNO) were detected, and we determined the relative renal gene expression levels of alpha smooth muscle actin (α-SMA), hydroxyproline, interleukin 10 (IL-10), tumour necrosis factor alpha (TNF-α) and caspase-3. The results showed significant deterioration of blood glucose, sIns, lipid profiles, kidney function and renal histopathology in fructose/ethanol-fed rats. Additionally, markers of inflammation, fibrosis, apoptosis and oxidative stress were upregulated. The administration of rilmenidine or clonidine significantly improved blood glucose and sIns levels and reduced renal dysfunction. Our work showed that chronic, sequential fructose and ethanol administration induced fasting hyperglycaemia and renal impairment, and these effects were ameliorated by I1R agonists.

Hesperidin protects against stress induced gastric ulcer through regulation of peroxisome proliferator activator receptor gamma in diabetic rats.

Stress induced gastric ulcer is a serious health problem in diabetic patients. Some studies reported that hesperidin (HDN), a citrus bioflavonoid, can bind to and stimulate peroxisome proliferator-activator receptor-gamma (PPAR-γ) which may mediate its antidiabetic, anti-inflammatory and anti-oxidant effects. This work aims to study the possible protective effect of HDN against stress induced gastric ulcer in diabetic rats as well as the possible involvement of PPARγ in this effect. Type 2 diabetes was induced using streptozotocin and nicotinamide. Diabetic rats received either HDN (100 mg/kg/day, orally) & omeprazole (20 mg/kg/day, orally) or HDN (100 mg/kg/day, orally) + GW9662, PPARγ antagonist, (1 mg/kg/day, i.p.) for 8 weeks then acute gastric injury was induced by cold restraint stress technique. Glycemic controls and gastroprotective effects were evaluated by measuring serum levels of glucose and insulin, gastric free and total acidity and gastric ulcer indices. Histopathological examination of gastric mucosa was also performed. To determine the underlying mechanism of action, gastric mucosal expression of nuclear factor (erythroid-derived 2)-like 2 (Nrf2), hemeoxygenase-1 (HO-1), cluster of differentiation 45 (CD45), cyclooxygenase-2 (COX-2), nuclear factor kappa B (NFκB) and inducible nitric oxide synthase (iNOS), gastric contents of reduced glutathione (GSH), malondialdehyde (MDA), tumor necrosis factor alpha (TNF-α) and nitric oxide (NO); as well as superoxide dismutase (SOD) and catalase activities were measured. HDN significantly improved glycemic level; it also reduced gastric acidity and gastric ulcer index and histopathological changes comparable to that produced by omeprazole. Moreover, HDN reduced lipid peroxidation and inflammatory markers levels and enhanced antioxidant capacity. The use of GW9662 significantly abrogated the gastric protective effect of HDN as well as reduced the antioxidant and anti-inflammatory effects. Our work showed, for the first time that, HDN has promising protective effect against stress induced gastric ulcer in diabetic rats through activation of PPARγ.

Ameliorative effects of clonidine on ethanol induced kidney injury in rats: Potential role for imidazoline-1 receptor.

Chronic alcoholism is a risk factor for kidney injury. Clonidine is an α2-adrenergic receptor/imidazoline-1 receptor agonist that can reduce blood pressure and maintain renal functions. This study aims to investigate the possible ameliorative effects of clonidine on ethanol induced kidney injury and its mechanism of action. Kidney injury was induced in rats by adding ethanol to drinking water for eight weeks. Clonidine effects on kidney functions and histopathology were measured. Moreover, phentolamine (α-adrenergic receptor antagonist), efaroxan (imidazoline-1 receptor antagonist) and rilmenidine (imidazoline-1 receptor agonist) were used to clarify the role of imidazoline-1 receptor in mediating renal ameliorative effects. Also, the effect of clonidine on liver functions and metabolic changes, in addition to renal oxidative stress, inflammatory and apoptotic pathways were measured. Results showed that, clonidine improved renal functions and reduced ethanol induced renal inflammation and fibrosis. On the other hand, efaroxan, only, blocked clonidine effects on kidney functions. Rilmenidine decreased kidney injury like clonidine. Both clonidine and rilmenidine increased renal nischarin gene expression. Furthermore, clonidine improved liver functions, increased serum insulin and decreased serum advanced glycation end products (metabolic markers). Also, clonidine reduced renal oxidative stress as reflected by decreased myeloperoxidase, malondialdehyde, inducible nitric oxide synthase and total nitric oxide levels and increased superoxide dismutase level. Moreover, clonidine reduced renal tumor necrosis factor-α (inflammatory marker) and caspase-3 (apoptotic marker) levels, while increased renal prostaglandine E2 and interleukin-10 levels (anti-inflammatory markers). In conclusion, clonidine can reduce ethanol induced kidney injury, at least in part, by stimulating imidazoline-1 receptor signaling.

Sildenafil protects against bile duct ligation induced hepatic fibrosis in rats: Potential role for silent information regulator 1 (SIRT1).

Hepatic fibrosis is a potential health problem that may end with life-threatening cirrhosis and primary liver cancer. Recent studies point out to the protective effects of silent information regulator1 (SIRT1), against different models of organs fibrosis. This work aimed to investigate the possible protective effect of sildenafil (SIRT1 activator) against hepatic fibrosis induced by bile duct ligation (BDL). Firstly, three different doses of sildenafil (5, 10, 20mg/kg/day) were investigated; to detect the most protective one against BDL induced liver dysfunction and hepatic fibrosis. The most protective dose is then used; to study its effect on BDL induced SIRT1 downregulation, imbalance of oxidant/antioxidant status, increased inflammatory cytokines and fibrosis. Sildenafil (20mg/kg/day) was the most protective one, it caused upregulation of SIRT1, reduction of hepatic malondialdehyde (MDA) content, increase in expression of nuclear factor erythroid 2-related factor 2 (Nrf2), hemeoxygenease (HO)-1, reduced glutathione (GSH) content and superoxide dismutase (SOD) activity. Hepatic content of tumor necrosis factor-α (TNF-α) and nuclear factor κB (NFκB) expression & content displayed significant reductions with sildenafil treatment, Furthermore, sildenafil caused marked reductions of transforming growth factor (TGF)-ß content, expression of plasminogen activator inhibitor-1 (PAI-1), matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinase-1 (TIMP-1), α-smooth muscle actin (α-SMA), fibronectin, collagen I (α1) and hydroxyproline content. However, sildenafil protective effects were significantly reduced by co-administration of EX527 (SIRT1 inhibitor). Our work showed, for the first time that, sildenafil has promising protective effects against BDL induced liver dysfunction and hepatic fibrosis. These effects may be, in part, mediated by up regulation of SIRT1.

GSK-3ß heterozygous knockout is cardioprotective in a knockin mouse model of familial dilated cardiomyopathy.

Glycogen synthase kinase-3ß (GSK-3ß) plays a central role in both cardiac physiology and pathology. Herein we want to clarify the role of GSK-3ß in familial dilated cardiomyopathy. We generated a mouse model carrying a heterozygous knockout mutation of GSK-3ß (GSK-3ß(+/-) KO), together with a ΔK210 knockin mutation in cardiac troponin T (ΔK210 cTnT KI), which was proved to be one of the genetic causes of familial dilated cardiomyopathy (DCM). GSK-3ß(+/-) KO prevented the slow and rapid deterioration in left ventricular systolic function accompanying heart failure (HF) in DCM mice with heterozygous and homozygous ΔK210 cTnT KI mutations, respectively. GSK-3ß(+/-) KO also prevented cardiac enlargement, myocardial fibrosis, and cardiomyocyte apoptosis and markedly reduced the expression of cardiac ß-myosin heavy chain isoform, indicative of HF, in DCM mice with homozygous ΔK210 cTnT KI mutation. GSK-3ß(+/-) KO also extended the life span of these DCM mice. This study suggests that the inhibition of GSK-3ß is cardioprotective in familial DCM associated with ΔK210 cTnT mutation.