Renin angiotensin system (RAS) blockade reduces the progression of chronic kidney disease (CKD) independently of its antihypertensive effect. Ang II-induced fibrosis can be mediated by molecules such as klotho, peroxisome proliferator-activate receptor γ (PPAR-γ), and the Wnt/β-catenin pathway; however, the interaction among these molecules and RAS activation is not completely known. The aim of this study was to investigate a possible link between RAS, PPAR-γ, and Klotho in the 5/6 nephrectomy (NX) animals. NX rats presented hypertension that was blunted by both losartan and propranolol, however, only losartan was able to reduce the expression levels of fibronectin FSP1 and TGF-β in the remnant kidney. The anti-fibrotic Klotho and PPAR-γ were reduced in the remnant kidney, and losartan, but not propranolol, restored their levels. In contrast, the profibrotic Wnt 7a and Wnt 3 were upregulated and losartan prevented the increase in Wnts. In vitro, Ang II induced a decrease in both klotho and in PPAR-γ in Madin-Darby canine kidney (MDCK) cells, and this effect was blunted by losartan. However, klotho expression was increased by pioglitazone, an agonist of PPAR-γ, and suppressed by BADGE, an antagonist of PPAR-γ, suggesting that the effect of Ang II downregulating klotho is mediated by PPAR-γ. These data suggest that activation of the Wnt pathway together with downregulation of PPAR-γ that in turn suppresses klotho contribute to potentiating the profibrotic effect of Ang II.

β cell loss and dysfunction play a critical role in the progression of type 1 and type 2 diabetes. Identifying new molecules and/or molecular pathways that improve β cell function and/or increase β cell mass should significantly contribute to the development of new therapies for diabetes. Using the zebrafish model, we screened 4640 small molecules to identify modulators of β cell function. This in vivo strategy identified 84 stimulators of insulin expression which simultaneously reduced glucose levels. The insulin promoter activation kinetics for 32 of these stimulators were consistent with a direct mode of action. A subset of insulin stimulators, including the antidiabetic drug Pioglitazone, induced the coordinated upregulation of gluconeogenic pck1 expression, suggesting functional response to increased Insulin action in peripheral tissues. Notably, Kv1.3 inhibitors increased β cell mass in larval zebrafish and stimulated β cell function in adult zebrafish and in the STZ-induced hyperglycemic mouse model. In addition, our data indicate that cytoplasmic Kv1.3 regulates β cell function. Thus, using whole organism screening, we have identified new small molecule modulators of β cell function and glucose metabolism.

A series of thiazolidine derivatives were designed by docking into PPAR-γ active site. The structure of target was obtained from the protein data bank (PDB ID P37231). A library of 200 molecules was prepared on random basis. Molecular docking studies were performed using VLife MDS 4.3 software. After molecular docking studies, the 4-substituted-6-methyl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carboxylic acid N-[4-(2,4-dioxo-thiazolidin-5-ylidenemethyl)-phenyl]-hydrazides (4a-4h) were selected for synthesis. The progress of reaction and purity of the synthesized compounds were monitored by TLC and melting point. Structures of title compounds were confirmed by elemental analysis, IR, 1H NMR and mass spectral data. The antidiabetic activity of title compounds was performed using the Wistar rats by alloxan-induced method. The compounds have shown antidiabetic activity comparable with the standard drug pioglitazone. These findings suggest that potent antidiabetics can be generated by substituting nonpolar, electron withdrawing substituents at the fourth position of pyrimidine skeleton and hydrogen bond acceptor at the nitrogen of the thiazolidine nucleus, to inhibit peroxisome proliferator-activated receptor-γ.

The Angiotensin II Receptor Blocker (ARB) Telmisartan reduces inflammation through Angiotensin II AT1 receptor blockade and peroxisome proliferator-activated receptor gamma (PPARγ) activation. However, in a mouse microglia-like BV2 cell line, imitating primary microglia responses with high fidelity and devoid of AT1 receptor gene expression or PPARγ activation, Telmisartan reduced gene expression of pro-injury factors, enhanced that of anti-inflammatory genes, and prevented LPS-induced increase in inflammatory markers. Using global gene expression profiling and pathways analysis, we revealed that Telmisartan normalized the expression of hundreds of genes upregulated by LPS and linked with inflammation, apoptosis and neurodegenerative disorders, while downregulating the expression of genes associated with oncological, neurodegenerative and viral diseases. The PPARγ full agonist Pioglitazone had no neuroprotective effects. Surprisingly, the PPARγ antagonists GW9662 and T0070907 were neuroprotective and enhanced Telmisartan effects. GW9226 alone significantly reduced LPS toxic effects and enhanced Telmisartan neuroprotection, including downregulation of pro-inflammatory TLR2 gene expression. Telmisartan and GW9662 effects on LPS injury negatively correlated with pro-inflammatory factors and upstream regulators, including TLR2, and positively with known neuroprotective factors and upstream regulators. Gene Set Enrichment Analysis (GSEA) of the Telmisartan and GW9662 data revealed negative correlations with sets of genes associated with neurodegenerative and metabolic disorders and toxic treatments in cultured systems, while demonstrating positive correlations with gene sets associated with neuroprotection and kinase inhibition. Our results strongly suggest that novel neuroprotective effects of Telmisartan and GW9662, beyond AT1 receptor blockade or PPARγ activation, include downregulation of the TLR2 signaling pathway, findings that may have translational relevance.

To investigate the role of the peroxisome proliferator-activated receptor-γ (PPARγ) in the progression of cholesterol gallstone disease (CGD), C57bl/6J mice were randomized to the following groups (n=7/group): L (lithogenic diet, LGD), LM (LGD+pioglitazone), CM (chow diet+pioglitazone), and NC (normal control, chow diet). Gallbladder stones were observed by microscopy. Histological gallbladder changes were assessed. Bile acids (BA) and cholesterol were measured in the serum, bile, and feces. Proteins and mRNA expression of genes involved in BA metabolism and enterohepatic circulation were assessed by western blotting and real-time RT-PCR. PPARγ activation was performed in LO2 cell by lentivirus transfection and in Caco2 cell by PPARγ agonist treatment. Downregulation of farnesoid X receptor (FXR) by small interference RNA (siRNA) was performed in L02 cells and Caco2 cells, respectively. Results showed that pharmacological activation of PPARγ by pioglitazone prevents cholesterol gallstone formation by increasing biliary BA synthesis and enterohepatic circulation. Activated PPARγ induced the expression of genes involved in enterohepatic circulation and bile acid synthesis (like PCG1α, BSEP, MRP2, MRP3, MRP4, NTCP, CYP7A1, CYP27A1, ASBT, OSTα, and OSTβ). Downregulation of FXR repressed expression of partial genes involved in BA enterohepatic circulation. These findings suggest a new function of PPARγ in preventing CGD by handling BA synthesis and transport through a FXR dependent or independent pathway.

The present work aims to determine the effect of pioglitazone on in-vitro albumin glycation and AGE-RAGE induced oxidative stress and inflammation. Bovine serum albumin was glycated by methylglyoxal in absence or presence of pioglitazone. Glycation markers (fructosamine, carbonyl groups, β-amyloid aggregation, thiol groups, bilirubin binding capacity and AOPP); protein conformational changes (native-PAGE and HPLC analysis) were determined. Cellular study was done by estimating antioxidants, ROS levels, expression profile of membrane RAGE, NF-κB and levels of inflammatory cytokines (IL-6, TNF-α) using HEK-293 cell line. We observed that levels of glycation markers were reduced at higher concentration of pioglitazone as compared to glycated albumin. Structural analysis of glycated albumin showed inhibition of protein migration and structural changes when treated with pioglitazone. Pioglitazone has potentially restored cellular antioxidants and reduced levels of IL-6 and TNF-α by declining expression of membrane RAGE and NF-κB. In conclusion, pioglitazone preferentially binds to protein and alleviates protein structural changes by maintaining its integrity. Additionally, it suppresses RAGE and NF-κB levels hence alleviate cellular oxidative stress and inflammation.

Preservation of hepatic phenotype and functions in vitro has always been a great challenge for the reconstruction of liver tissue engineering and in pharmaceutical research studies. Human induced hepatocytes (hiHeps) generated from fibroblasts can be reproducible with almost normal levels of liver specific functions, which are considered as a new source of hepatocytes for biomedical applications. Moreover, paper has served as an attractive biocompatible material for cell-based applications. In this study, we established a simple paper-based scaffold array for creating a 3D liver co-culture model that enabled the assessment of drug induced hepatotoxicity. The hiHeps co-cultured with HUVECs exhibited a 3D like morphology and maintained the liver specific functions of producing albumin and urea for up to 2 months. In addition, the hiHeps in this co-cultured model maintained a higher expression of cytochrome P450 genes as compared with a monolayer culture on a plate and a single culture on paper of hiHeps, revealing a marked enhancement of hepatic functions in the 3D liver co-culture model. Moreover, the 3D liver co-culture model was exposed to acetaminophen (APAP) and pioglitazone, exhibiting near physiological hepatotoxic responses compared to those of the monolayer cultures. Taken together, the low-cost and bioactive paper scaffold could offer great opportunities as 3D in vitro platforms for tissue engineering applications and high-throughput drug testing.