Renoprotective Effect of Liraglutide Is Mediated via the Inhibition of TGF-Beta 1 in an LLC-PK1 Cell Model of Diabetic Nephropathy

Anti-obesity pharmacotherapy in adults with chronic kidney disease

Obesity is a leading risk factor for the development and progression of kidney disease and a major barrier to optimal management of patients with chronic kidney disease. While in the past anti-obesity drugs offered only modest weight loss efficacy in exchange for various safety and tolerability risks, a wave of safer, more tolerable, and more effective treatment options is transforming the management of obesity. This review evaluates current and future pharmacologic anti-obesity therapy in adults through a kidney-oriented lens. It also explores the goals of anti-obesity treatment, describes the underlying putative mechanisms of action, and raises important scientific questions that deserve further exploration in people with chronic kidney disease.

Novel insights into the augmented effect of curcumin and liraglutide in ameliorating cisplatin-induced nephrotoxicity in rats: Effects on oxidative stress, inflammation, apoptosis and pyroptosis via GSK-3β

Cisplatin dose-dependent nephrotoxicity is a major issue limiting its proper use in cancer treatment. Inflammation, redox imbalance, and dysregulated cell death are the most plausible underlying pathomechanics. Curcumin and the glucagon-like peptide-1 receptor agonist, liraglutide, have been investigated in various experimental models for their antioxidant, anti-inflammatory, and cell death modulatory effects. Hence, this work was designed to investigate curcumin and liraglutide nephroprotective effects and how they behave together against cisplatin-induced acute kidney injury (AKI) in an experimental Wistar rat model. The study comprised 61 rats divided randomly into 6 unequal groups: control I and II, cisplatin-induced nephrotoxicity, curcumin-treated, liraglutide-treated, and co-treated groups. Renal index, serum nephrotoxicity markers (Cr, BUN, NGAL), renal glycogen synthase kinase-3 β (GSK-3β), oxidant/antioxidant parameters (MDA, MPO, GSH, NQO1, HO-1), and inflammatory biomolecules (TNF-α, IL-1β) were assayed. Moreover, renal cleaved-caspase3 and the pyroptotic biomolecules (nod-like receptor family pyrin domain containing 3, gasdermin D N-terminal fragment) were immunoassayed. Furthermore, relative renal expression of both nuclear factor erythroid 2-related factor 2 (Nr-F2) and caspase1 was evaluated by qRT-PCR. Histopathological examination of renal tissue was carried out along with detection of Bcl-2 and Bax immunoreactivity. Cisplatin induced acute renal damage, augmented inflammation, dysregulated redox balance and induced apoptosis and pyroptosis. On the other hand, curcumin and liraglutide corrected the dysregulated mechanisms and normalized results to a great extent. Mutual use of curcumin and liraglutide exerted the greatest effect in the co-treatment group. Nr-F2/HO-1 axis and GSK-3β play a master role in their nephroprotective effect. In conclusion, curcumin and liraglutide have an ameliorative effect against cisplatin-induced nephrotoxicity and can be used alone or better in combination owing to their augmented effect launching promising avenues for cancer patients under cisplatin treatment, retarding AKI and enabling them to gain the best protocol effectiveness.

Beraprost sodium attenuates the development of myocardial fibrosis after myocardial infarction by regulating GSK-3β expression in rats

OBJECTIVE

The aim of this study was to elucidate the mechanism of beraprost sodium (BPS) in the intervention of myocardial fibrosis after myocardial infarction (MI) through glycogen synthase kinase-3β (GSK-3β) and to provide new ideas for intervention in myocardial fibrosis.

MATERIALS AND METHODS

MI model rats given BPS and cardiac fibroblasts (CFs) treated with BPS and TGF-β. HE staining and Masson staining were used to detect the pathological changes of myocardial tissue. Fibrotic markers were detected by immunohistochemical staining. The expressions of GSK-3β, cAMP response element binding protein (CREB), and p-CREB were analyzed by qPCR and western blot analysis. EDU staining was used to detect the proliferation of CFs. The promoter activity of GSK-3β was detected by luciferase assay. Chromatin immunoprecipitation assay was used to detect the binding levels of GSK-3β promoter and Y-box binding protein 1 (YBX1). The levels of intracellular cyclic adenosine monophosphate (cAMP) were analyzed by enzyme-linked immunosorbent assay (ELISA).

RESULTS

After operation, BPS improved myocardial fibrosis and upregulated GSK-3β protein expression in male SD rats. BPS can down-regulate α-smooth muscle actin (α-SMA) level and up-regulate GSK-3β protein expression in CFs after TGF-β stimulation. Furthermore, GSK-3β knockdown can reverse the effect of BPS on TGF-β-activated CFs, enhance α-SMA expression, and promote the proliferation of CFs. BPS could regulate GSK-3β expression by promoting the binding of GSK-3β promoter to YBX1. BPS induced upregulation of p-CREB and cAMP, resulting in reduced fibrosis, which was reversed by the knockdown of GSK-3β or prostaglandin receptor (IPR) antagonists.

CONCLUSION

BPS treatment increased the binding of YBX1 to the GSK-3β promoter, and GSK-3β protein expression was upregulated, which further caused the upregulation of p-CREB and cAMP, and finally inhibited myocardial fibrosis.

Insights into the Role of Glucagon Receptor Signaling in Metabolic Regulation from Pharmacological Inhibition and Tissue-Specific Knockout Models

While glucagon has long been recognized as the primary counter hormone to insulin’s actions, it has recently gained recognition as a metabolic regulator with its effects extending beyond control of glycemia. Recently developed models of tissue-specific glucagon receptor knockouts have advanced our understanding of this hormone, providing novel insight into the role it plays within organs as well as its systemic effects. Studies where the pharmacological blockade of the glucagon receptor has been employed have proved similarly valuable in the study of organ-specific and systemic roles of glucagon signaling. Studies carried out employing these tools demonstrate that glucagon indeed plays a role in regulating glycemia, but also in amino acid and lipid metabolism, systemic endocrine, and paracrine function, and in the response to cardiovascular injury. Here, we briefly review recent progress in our understanding of glucagon’s role made through inhibition of glucagon receptor signaling utilizing glucagon receptor antagonists and tissue specific genetic knockout models.