Sacubitril/valsartan alleviates sunitinib-induced cardiac fibrosis and oxidative stress via improving TXNIP/TRX system and downregulation of NF-ĸB/Wnt/β-catenin/SOX9 signaling

We aimed in this study to investigate the possible cardioprotective effects of sacubitril/valsartan against sunitinib-induced cardiac fibrosis (CF) and oxidative stress via targeting thioredoxin-interacting protein/thioredoxin (TXNIP/TRX) system and nuclear factor-kappa B (NF-κB)/Wingless-related MMTV integration site (Wnt)/β-catenin/Sex-determining region Y box 9 (SOX9) signaling. CF was induced in male Wistar albino rats by cumulative dose of sunitinib (300 mg/kg, given over 4 weeks as: 25 mg/kg orally, three times a week), which were co-treated with sacubitril/valsartan (68 mg/kg/day, orally) for four weeks. Significant elevation in blood pressure, cardiac inflammatory and fibrotic markers besides cardiac dysfunction were observed. These alterations were associated with disruption of TXNIP/TRX system, upregulation of NF-κB/Wnt/β-catenin/SOX9 pathway along with marked increase in lysyl oxidase (LOX) and matrix metalloproteinase-1 (MMP-1) expressions and extensive deposition of collagen fibers in cardiac tissues. Luckily, sacubitril/valsartan was able to reverse all of the aforementioned detrimental effects in sunitinib-administered rats. These findings illustrate a potential role of sacubitril/valsartan in alleviating CF and oxidative stress induced by sunitinib via antioxidant, anti-inflammatory and antifibrotic properties. These remarkable effects of sacubitril/valsartan were mediated by its ability to improve TXNIP/TRX system and downregulate NF-κB/Wnt/β-catenin/SOX9 signaling in addition to decreasing LOX and MMP-1 expressions in cardiac tissues. In summary, this study highlights sacubitril/valsartan as a potential therapeutic agent in mitigating CF and oxidative stress especially in cancer cases treated with sunitinib.

Secukinumab and Black Garlic Downregulate OPG/RANK/RANKL Axis and Devitalize Myocardial Interstitial Fibrosis Induced by Sunitinib in Experimental Rats

Sunitinib has been associated with several cardiotoxic effects such as cardiac fibrosis. The present study was designed to explore the role of interleukin (IL)-17 in sunitinib-induced myocardial fibrosis (MF) in rats and whether its neutralization and/or administration of black garlic (BG), a form of fermented raw garlic (Allium sativum L.), could extenuate this adverse effect. Male Wistar albino rats received sunitinib (25 mg/kg three times a week, orally) and were co-treated with secukinumab (3 mg/kg, subcutaneously, three times total) and/or BG (300 mg/kg/day, orally) for four weeks. Administration of sunitinib induced significant increase in cardiac index, cardiac inflammatory markers, and cardiac dysfunction that were ameliorated by both secukinumab and BG, and to a preferable extent, with the combined treatment. Histological examination revealed disruption in the myocardial architecture and interstitial fibrosis in cardiac sections of the sunitinib group, which were reversed by both secukinumab and BG treatments. Both drugs and their co-administration restored normal cardiac functions, downregulated cardiac inflammatory cytokines, mainly IL-17 and NF-κB, along with increasing the MMP1/TIMP1 ratio. Additionally, they attenuated sunitinib-induced upregulation of the OPG/RANK/RANKL axis. These findings highlight another new mechanism through which sunitinib can induce interstitial MF. The current results propose that neutralizing IL-17 by secukinumab and/or supplementation with BG can be a promising therapeutic approach for ameliorating sunitinib-induced MF.

Dulaglutide mitigates high dietary fructose-induced renal fibrosis in rats through suppressing epithelial-mesenchymal transition mediated by GSK-3β/TGF-β1/Smad3 signaling pathways

AIMS

High dietary fructose consumption has been linked to the development of renal fibrosis. Dulaglutide is a long acting glucagon like peptide-1 (GLP-1) analog, showing some renoprotective properties; however its action on renal fibrosis remains uncertain. We investigated the effect of dulaglutide on fructose-induced renal fibrosis in comparison to pirfenidone, as well-established anti-fibrotic drug, and the contribution of epithelial-mesenchymal transition (EMT) process and its upstream signaling.

MAIN METHODS

Six week-old male Wistar albino rats received 10%w/v fructose solution in drinking water for 24 weeks and co-treated with either pirfenidone (100 mg/kg/day, orally) or dulaglutide (0.2 mg/kg/week, s.c) for the last four weeks. Lipid profile, glucose homeostasis, kidney functions were assessed. Kidneys were harvested for biochemical and histological analyses.

KEY FINDINGS

High dietary fructose consumption for 24 weeks induced insulin resistance, dyslipidemia and renal dysfunction that were ameliorated by dulaglutide and pirfenidone to lesser extent. Histological examination revealed histological lesions and interstitial fibrosis in renal sections of high fructose-fed rats, which were reversed by dulaglutide or pirfenidone treatment. Both drugs modulated the EMT-related proteins by increasing the epithelial marker, E-cadherin, while suppressing the mesenchymal markers, vimentin and alpha-smooth muscle actin (α-SMA) in renal tissue. Moreover, both drugs attenuated fructose-induced upregulation of GSK-3β/TGF-β1/Smad3 signaling.

SIGNIFICANCE

These findings suggest that dulaglutide can emerge as a promising therapeutic agent for fructose-induced renal fibrosis. These results add mechanistic insights into the anti-fibrotic action of dulaglutide through suppressing EMT and the upstream GSK-3β/TGF-β1/Smad3 signaling.

Infliximab ameliorates tumor necrosis factor-alpha exacerbated renal insulin resistance induced in rats by regulating insulin signaling pathway

Infliximab (IFX), a monoclonal antibody for tumor necrosis factor-alpha (TNF-α), is known to restore blood glucose homeostasis. However, its effects on improving renal insulin resistance (IR) are not yet studied. So we investigate the impact of infliximab on renal insulin signaling pathway in IR rat model regarding to metformin (MET). The induced IR was confirmed by a high oral glucose tolerance test, an elevation of lipid profile and the homeostatic model assessment of insulin resistance 2 (HOMA-IR 2) values. Subsequently, IR rats were concurrently treated with either MET (100 mg/kg/day) or IFX (one dose 5 mg/kg) besides IR and normal control (NC) groups. Four weeks later, IR control rats displayed hyperglycemia, hyperinsulinemia and elevation in HOMA-IR 2, renal function markers and renal tissue TNF-α, interleukins-1β and 6 (Il-1β, IL-6) and suppressor of cytokines signaling 3 (SOCS3) contents as well as glomerulosclerosis when compared to NC group. Additionally, the phosphorylation of renal insulin receptor substrate 1 (IRS1), phosphatidylinositol 3-kinase (PI3K) and protein kinase B (Akt) were markedly impaired. Treatment with either MET or IFX significantly improved IR and kidney functions. The effects of the drugs were achieved by the downregulation of renal inflammatory cytokines and SOCS3 levels and the amelioration of the renal IRS1/PI3K/Akt pathway. In conclusion, MET and IFX ameliorated the TNF-α worsening effect on IR in rat renal tissues by regulating insulin signaling. Interestingly, infliximab was superior to metformin in regulating insulin signaling pathway. Therefore, infliximab could be used as an adjuvant therapy in improving renal IR.

Management of cardiac fibrosis in diabetic rats; the role of peroxisome proliferator activated receptor gamma (PPAR-gamma) and calcium channel blockers (CCBs)

BACKGROUND

Diabetes mellitus (DM) and hypertension (HTN) are accused of being responsible for the development of the cardiac fibrosis due to severe cardiomyopathy.

METHODS

Blood glucose (BG) test was carried out, lipid concentrations, tumor necrosis factor alpha (TNF-α), transforming growth factor beta (TGF-β), matrix metalloproteinase (MMP-2), collagen-I and collagen-III were measured in male Albino rats weighing 179-219 g. The rats were divided into five groups, kept on either control diet or high fat diet (HFD), and simultaneously treated with rosiglitazone (PPAR-gamma) only for one group with 3 mg/kg/day via oral route for 30 days, and with rosiglitazone and felodipine combination for another group with 3 mg/kg/day and 5 mg/kg/day, respectively via oral route for 30 days.

RESULTS

Diabetic hypertensive (DH) rats which fed on a HFD, injected with streptozotocin (STZ) (i.p.) and obstruction for its right kidney was occurred develop hyperglycemia, hypertension, cardiac fibrosis, hypertriglyceridemia, hypercholesterolemia, increased TNF-α, increased TGF-β, decreased MMP-2, increased collagen-I and increased collagen-III, when compared to rats fed on control diet. Treating the DH rats with rosiglitazone only causes a significant decrease for BG levels by 52.79%, triglycerides (TGs) by 24.05%, total cholesterol (T-Chol) by 30.23%, low density lipoprotein cholesterol (LDL-C) by 40.53%, TNF-α by 20.81%, TGF-β by 46.54%, collagen-I by 48.11% and collagen-III by 53.85% but causes a significant increase for MMP-2 by 272.73%. Moreover, Treating the DH rats with rosiglitazone and felodipine combination causes a significant decrease for BG levels by 61.08%, blood pressure (BP) by 16.78%, TGs by 23.80%, T-Chol by 33.27%, LDL-C by 45.18%, TNF-α by 22.82%, TGF-β by 49.31%, collagen-I by 64.15% and collagen-III by 53.85% but causes a significant increase for MMP-2 by 290.91%. Rosiglitazone alone failed to decrease the BP in DH rats in the current dosage and duration.

CONCLUSION

Our results indicate that the co-existence of diabetes and hypertension could induce cardiomyopathy which could further result in cardiac fibrosis, and that combination treatment with rosiglitazone and felodipine has a great protective role against the metabolic abnormalities, meanwhile, the treatment with rosiglitazone alone has a protective role with a minimal effect against these abnormalities and has no effect on decreasing BP in these cases which may lead to coronary artery diseases (CADs) in future.