miR-485 suppresses inflammation and proliferation of mesangial cells in an in vitro model of diabetic nephropathy by targeting NOX5.

Diabetic nephropathy (DN) is among the common complications of diabetes and is a major cause of end-stage kidney disease. Emerging data indicate that renal inflammation is involved in DN progression and aggravation. Still, the exact cellular mechanisms remain unclear. Dysregulated expression of microRNAs (miRNAs) is associated with multiple diseases, including DN. The relationship between miRNAs and inflammation in DN is also unexplored. Here, we evaluated the role of miR-485 in mediating the response of human mesangial cells (HMCs) to a high glucose (HG) concentration, and the potential underlying mechanism. We found that miR-485 expression is significantly decreased in HG-stimulated HMCs. Overexpression of miR-485 suppressed HG-induced proliferation of HMCs. Lower production of proinflammatory cytokines (i.e., TNF-α, IL-1ß, and IL-6) was observed in miR-485-overexpressing HMCs. Overexpression of miR-485 markedly suppressed the overexpression of extracellular-matrix proteins, e.g., collagen IV (Col IV) and fibronectin (FN), in HG-stimulated HMCs. Furthermore, miR-485 suppressed the expression of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 5 (NOX5), restrained the HG-induced HMC proliferation, downregulated the expression of proinflammatory cytokines, and inhibited the production of extracellular-matrix proteins in HMCs. These results provide new insights into the involvement of the miR-485-NOX5 signaling pathway in DN progression.

MiR-455-3p suppresses renal fibrosis through repression of ROCK2 expression in diabetic nephropathy.

Emerging evidence has shown that microRNAs (miRNAs) play a mediatory role in the pathogenesis of diabetic nephropathy (DN), but the function of the involved miRNAs is still incomplete. Here, we found that miR-455-3p was down-regulated in the human mesangial cells (HMC) and human proximal tubule epithelial cells (HK-2) stimulated with high glucose (HG) or transforming growth factor beta 1 (TGF-ß1). Rho-associated coiled coil-containing protein kinase 2 (ROCK2) was identified as a directed target of miR-455-3p. Overexpression of ROCK2 significantly attenuated the inhibitory effects of miR-455-3p on cell proliferation, extracellular matrix (ECM) synthesis and epithelial-mesenchymal transition (EMT) in HG-treated cells. Furthermore, the DN model was prepared by using high-fat feeding combined with Streptozotocin (STZ) induced rats, and the DN group was treated by injecting miR-455-3p agomir. The results of periodic acid-Schiff (PAS) and Masson staining showed that miR-455-3p overexpression improved the pathological changes of glomerular hypertrophy, mesangial amplification, and renal fibrosis. Additionally, miR-455-3p overexpression decreased ROCK2, proliferating cell nuclear antigen (PCNA) and Collagen I levels, and also reduced inflammatory cytokines TNF-α, MCP-1 and IL-1ß levels in vivo. Altogether, these results suggest that miR-455-3p plays an essential role in the treatment of renal fibrosis through repressing ROCK2 expression; and miR-455-3p might be an effective therapy for DN.

Urinary RBP and NGAL Levels are Associated with Nephropathy in Patients with Type 2 Diabetes.

BACKGROUND/AIMS: The diagnosis of type 2 diabetic nephropathy (T2DN) patients is important to prevent the long-term damaging effects of kidney loss in patients with diabetes and is decisive for patient outcomes. The aim of this study was to explore urine retinol binding protein (RBP) and neutrophil gelatinase-associated lipocalin (NGAL) in T2DN patients with and without albuminuria. METHODS: A total of 293 T2DN patients were divided into three groups according to their urine albumin/urine creatinine ratio (UACR): normoalbuminuria group (UACR<30 mg/g, n=100), microalbuminuria group (UACR 30-300 mg/g, n=100) and macroalbuminuria group (UACR>300 mg/g, n=93); 50 non-diabetic subjects were recruited as the control group. The levels of urine RBP, NGAL, TNF-α and IL-18 in T2DN patients and non-diabetic subjects were measured using ELISA assays. RESULTS: We first analyzed the clinical characteristics of the control and T2DN groups and found that urine NGAL, RBP, TNF-α and IL-18 levels were significantly increased and significantly correlated with the degree of albuminuria. In addition, univariate linear regression analysis showed that urine RBP was associated with UACR, BMI, Scr, BUN, TG, disease duration, SBP, NGAL, TNF-α and IL-18 levels, and urine NGAL was positively correlated with UACR, Scr, BUN, RBP, TNF-α and IL-18 levels. CONCLUSION: The results indicate that urine levels of NGAL and RBP may be independently associated with albuminuria in T2DN and may serve as novel biomarkers for the identification of T2DN.

Gentiopicroside Ameliorated Ductular Reaction and Inflammatory Response in DDC-induced Murine Cholangiopathies Model.

BACKGROUND: Cholangiopathies comprise a spectrum of diseases without curative treatments. Pharmacological treatments based on bile acid (BA) metabolism regulation represent promising therapeutic strategies for the treatment of cholangiopathies. Gentiopicroside (GPS), derived from the Chinese medicinal herb Gentianae Radix, exerts pharmacological effects on bile acid metabolism regulation and oxidative stress. OBJECTIVE: The present study aims to investigate the effect of GPS on 3,5-diethoxycarbonyl-1,4dihydrocollidine (DDC)-induced cholangiopathy. METHODS: Two independent animal experiments were designed to evaluate the comprehensive effect of GPS on chronic DDC diet-induced cholangiopathy, including bile duct obliteration, ductular reaction, BA metabolism reprogramming, liver fibrosis, oxidative stress and inflammatory responses. RESULTS: In the first pharmacological experiment, three doses of GPS (5, 25 and 125 mg/kg) were injected intraperitoneally into mice fed a DDC diet for 14 days. DDC induced a typical ductular reaction, increased periductal fibrosis and mixed inflammatory cell infiltration in the portal areas. GPS treatment showed dose-dependent improvements in the ductular reaction, BA metabolism, fibrosis, oxidative stress and inflammatory response. In the second experiment, a high dose of GPS was injected intraperitoneally into control mice for 28 days, resulting in no obvious histologic changes and significant serologic abnormalities in liver function. However, GPS inhibited DDC-induced oxidative stress, serum and hepatic BA accumulation, proinflammatory cytokine production, and immunocyte infiltration. Specifically, the GPS-treated groups showed decreased infiltration of monocyte-derived macrophages and CD4+ and CD8+ T lymphocytes, as well as preserved Kupffer cells. CONCLUSION: GPS alleviated chronic DDC diet-induced cholangiopathy disorder by improving the ductular reaction, periductal fibrosis, oxidative stress and inflammatory response. Its dosage-dependent pharmacological effects indicated that GPS warrants its further evaluation in clinical trials for cholangiopathy.

Costunolide alleviated DDC induced ductular reaction and inflammatory response in murine model of cholestatic liver disease.

Purpose: Cholestatic liver diseases are groups of hepatobiliary diseases without curative drug-based therapy options. Regulation of bile acid (BA) metabolism, hepatoperiductal fibrosis, and inflammatory response indicated present novel methods for the treatment of cholestatic liver disease. Costunolide (COS) from herb Saussurea lappa exerts a pharmacological effect of regulation of BA metabolism, liver fbrosis and inflammatory response. The present study aimed to clarify the pharmacodynamic effects of COS against the murine model of cholestatic liver disease. Methods: We established a murine model of cholestatic liver disease through chronic feeding of 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) diet for 28 days. Two independent in vivo experiments were designed to reveal the pharmacological effect of COS against cholestatic liver disease. In the first experiment, two dosages of COS (10 and 30 mg/kg) were intraperitoneally injected into model mice daily for 14 days. In the second experiment, high dosage of COS (30 mg/kg) was intraperitoneally injected into control and model mice daily for 28 days. Results: In the evaluation of the hepatoprotective effect of COS, COS showed dosage-dependent improvement of cholestatic liver disease, including ductular reaction, hepatoperiductal fibrosis, and inflammatory response. The mechanism of COS-mediated hepatoprotective effects mainly relies on the regulation of BA metabolism, and the inflammatory response. DDC diet feed induced hepatic BA metabolism, transport and circulation dysfunction. COS treatment not only regulated the BA metabolism and transport gene, but also reprogrammed hepatic primary and secondary BA concentrations. DDC induced hepatic infiltrated monocytes derived macrophages and lymphocytes were inhibited, while Kupffer cells were preserved by COS treatment. The liver elevating inflammatory cytokines of DDC diet feed were alleviated by COS. Moreover, high dosage of 30 mg/kg COS treatment for 28 days resulted in no significant serological changes and no obvious hepatic histopathological changes when compared with control mice. Conclusion: COS protected against DDC diet feeding-induced cholestatic liver disease since COS regulated BA metabolism, ductular reaction, hepatoperiductal fibrosis and inflammatory response. COS is suggested as a potential natural product for the treatment of cholestatic liver disease.

Palmitate contributes to insulin resistance through downregulation of the Src-mediated phosphorylation of Akt in C2C12 myotubes.

The mechanisms of free fatty acid (FFA)-induced peripheral insulin resistance remain elusive. This study aimed to investigate the effect of palmitate, a saturated fatty acid, on glucose metabolism in C2C12 myotubes, and to explore the underlying mechanisms. In it, palmitate decreased insulin-stimulated glucose uptake and consumption in a dose-dependent manner, and it reduced the insulin-stimulated phosphorylation of Akt at Thr308 and Ser473, but had no effect on the protein expression of PI3K-p85 or the activity of PI3K. Additionally, it inhibited the insulin-stimulated phosphorylation of Src at Tyr416, causing a reduction in the Src-mediated phosphorylation of Akt. Inhibition of Src by PP2 resulted in decreases in insulin-stimulated glucose uptake and phosphorylation of Src at Tyr416 and Akt at Thr308 and Ser473. The findings indicate that palmitate contributes to insulin resistance by inhibiting the Src-mediated phosphorylation of Akt in C2C12 myotubes, and this provides insight into the molecular mechanisms of FFA-induced insulin resistance.

Fisetin Attenuates Diabetic Nephropathy-Induced Podocyte Injury by Inhibiting NLRP3 Inflammasome.

Diabetic nephropathy (DN) is one of the primary complications of diabetes. Fisetin is a flavonoid polyphenol that is present in several vegetables and fruits. The present study investigated the mechanisms of fisetin in DN-induced podocyte injury both in vitro and in vivo. The results revealed that fisetin ameliorated high glucose (HG)-induced podocyte injury and streptozotocin (STZ)-induced DN in mice. CDKN1B mRNA expression in the glomeruli of patients with DN decreased based on the Nephroseq dataset, and fisetin reversed CDKN1B expression at mRNA and protein levels in a dose-dependent manner in podocytes and mice kidney tissues. Furthermore, fisetin suppressed the phosphorylation of P70S6K, a downstream target of CDKN1B, activated autophagosome formation, and inhibited Nod-like receptor protein 3 (NLRP3) inflammasomes. Interfering CDKN1B reduced the protective effects of fisetin against high glucose-induced podocyte injury. Molecular docking results revealed a potential interaction between fisetin and CDKN1B. In summary, the present study revealed that fisetin alleviated high glucose-induced podocyte injury and STZ-induced DN in mice by restoring autophagy-mediated CDKN1B/P70S6K pathway and inhibiting NLRP3 inflammasome.

Solar-driven aromatic aldehydes: green production from mandelic acid derivatives by a Co(ii)/C3N4 combined catalyst in aqueous media.

According to the requirements for sustainable development, reclaiming fine chemicals from wastewater under mild conditions is an extremely significant line of research. A low-cost and high-efficiency polydentate chelate- and polymeric Co(ii)-based complex (Co-L)-loaded C3N4 photocatalyst (Co-L/C3N4) was constructed and used to convert aromatic mandelic acids in wastewater at room temperature. The BET specific surface area increased from 28 m2 g-1 to 68 m2 g-1, indicating its excellent absorptive character. The light absorption range of Co-L/C3N4 reached 650 nm, while the band energy reduced to 2.30 eV, which caused a significant enhancement in photocatalytic activity. The conversion of substituted mandelic acids was more than 90% due to the photoactivity of Co-L/C3N4. Time-resolved PL spectra indicated the remarkable separation of the photogenerated electron-hole pairs in Co-L/C3N4. Furthermore, the UV-vis and in situ FTIR spectra indicated the formation of aldehyde groups in the selective oxidation process, which provided support for the plausible catalytic mechanism.

An in-depth mechanistic study of the p-hydroxyphenylglycine synthetic process using in situ ATR-IR spectroscopy.

In this study, an in situ ATR-IR technique was used as a powerful tool to gain insight into the synthetic process of p-hydroxyphenylglycine (p-HPG) by the sulfamic acid-glyoxylic acid-phenol method. Combined with other chemical and instrumental analysis technologies, the reaction sequence and key intermediates of this one-pot reaction were determined, and two concomitant reaction paths have been put forward for the first time. The possible reaction mechanism has been suggested, and the reaction efficiency of each path is discussed in detail. Through the optimization of the experimental parameters, an approximately 40% increase in the final product yield was achieved compared with previous reports. We believe that this study will without a doubt trigger research interest in understanding the industrial production process of important chemicals and pharmaceuticals and as a result will promote the sustainable development and application of novel, efficient chemical reaction routes.

ß-Arrestins: multifunctional signaling adaptors in type 2 diabetes.

ß-arrestins are not only well-known negative regulators of G protein-coupled receptor (GPCR) signaling, but also important adaptors in modulating the strength and duration of cellular signaling by scaffolding and interacting with a lot of cytoplasmic proteins. While ß-arrestins are rather well described signal-mediated molecules, they are not generally associated with insulin signaling. But recent work has confirmed the difference from original thought. The current review aims to explore the emerging roles for ß-arrestins in regulating insulin action, inflammatory signal pathway and other cellular signaling which are associated with type 2 diabetes.

One-Pot Efficient Catalytic Oxidation for Bio-Vanillin Preparation and Carbon Isotope Analysis.

Vanillin (4-hydroxy-3-methoxybenzaldehyde) is one of the most widely used food spices. Aimed at bio-vanillin green production, the natural materials were directly catalytically oxidized efficiently in one pot under low O2 pressure (0.035 MPa) in the presence of a non-noble metal oxidation combined catalyst (NiCo2O4/SiO2 nanoparticles), which showed remarkable advantages of a short synthetic route and less industrial waste. The catalytic system showed good universality to many natural substrates with nearly 100% conversion and 86.3% bio-vanillin yield. More importantly, carbon isotope ratio investigations were employed to verify the origin of the organic matter. One hundred percent 14C content of the obtained vanillin was detected, which indicated that it was an efficient method to distinguish the vanillin from biomass or fossil materials. Furthermore, the 13C isotope examination showed effective distinguishing ability for the vanillin from a particular biomass source. The C isotope detection provides an effective method for commercial vanillin identification.

Effect and Mechanism of Aluminum(III) for Guaiacol-Glyoxylic Acid Condensation Reaction in Vanillin Production.

3-methoxy-4-hydroxymandelic acid (VMA) was the critical intermediate for the synthesis of vanillin by the glyoxylic acid method. Meanwhile, a valuable byproduct (2-hydroxy-3-methoxy-mandelic acid, o-VMA) was obtained during the reaction. Al3+ was found to be a helpful catalyst in increasing the selectivity for VMA and o-VMA. In the presence of Al3+, the selectivity for VMA and o-VMA increased from 83 to 88% and from 3 to 8%, respectively, while that of the helpless byproduct 2-hydroxy-3-methoxy-1,5-mandelic acid (di-VMA) decreased from 14% to less than 4%. The kinetics based on the kinetic equation of the condensation reaction was studied by the initial concentration method. The results indicated that the involvement of Al3+ could reduce the activation energy of the reaction on the basis of the Arrhenius equation. Combined with thermogravimetric analysis, in situ Fourier transform-infrared spectroscopy, and 1H NMR research, Al3+ was found to interact with guaiacol through Al-O and Al···H, which further improved the selectivity of the VMA and o-VMA and reduced the selectivity of di-VMA by adding the electronegativity of the ortho- and para-positions of hydroxyl groups of guaiacol.

Pollen Typhae total flavone improves insulin-induced glucose uptake through the ß-arrestin-2-mediated signaling in C2C12 myotubes.

Defects in insulin-stimulated glucose uptake in skeletal muscle result from the dysfunction of insulin signaling including the phosphatidylinositol-3 kinase (PI3K) pathway and a novel ß-arrestin-2-mediated signaling, which leads to insulin resistance (IR). Pollen Typhae, a Chinese herb, has been used for thousands of years in traditional Chinese medicine, and has the potential to inhibit the development of IR. We have previously reported that Pollen Typhae total flavone (PTF), the extract from Pollen Typhae, ameliorates high-glucose- and high-insulin-induced impairment of glucose uptake in 3T3-L1 adipocytes, but the mechanisms remain unclear. The objective of this study was to investigate the effects of PTF on glucose uptake, and to explore the underlying mechanisms in C2C12 myotubes. PTF improved insulin-stimulated glucose uptake in a dose- and time-dependent manner in C2C12 myotubes, and prevented palmitate-induced IR. Furthermore, PTF enhanced the basal gene expression of Src and Akt2, elevated the protein expression of ß-arrestin-2, Src and Akt, increased the phosphorylation of insulin receptor-ß at Tyr1150/1151 and Akt at Thr308/Ser473 in an insulin-dependent manner, but had no effects on the protein expression of PI3K-p85 or the activity of PI3K. Inhibition of Src but not PI3K restrained PTF-induced phosphorylation of Akt and glucose uptake. Our findings indicate that PTF improves insulin-induced glucose uptake via the ß-arrestin-2-mediated signaling in C2C12 myotubes.