Ursodeoxycholic acid and 4-phenylbutyrate prevent endoplasmic reticulum stress-induced podocyte apoptosis in diabetic nephropathy.

Endoplasmic reticulum (ER) stress, resulting from the accumulation of misfolded and/or unfolded proteins in ER membranes, is involved in the pathogenesis of diabetic nephropathy (DN). The aim of this study was to investigate the role of ER stress inhibitors ursodeoxycholic acid (UDCA) and 4-phenylbutyrate (4-PBA) in the treatment of DN in db/db mice. Findings have revealed that diabetic db/db mice were more hyperglycemic than their non-diabetic controls, and exhibited a marked increase in body weight, water intake, urine volume, fasting plasma glucose, systolic blood pressure, glucose and insulin tolerance. UDCA (40 mg/kg/day) or 4-PBA (100 mg/kg/day) treatment for 12 weeks resulted in an improvement in these biochemical and physical parameters. Moreover, UDCA or 4-PBA intervention markedly decreased urinary albuminuria and attenuated mesangial expansion in diabetic db/db mice, compared with db/db mice treated with vehicle. These beneficial effects of UDCA or 4-PBA on DN were associated with the inhibition of ER stress, as evidenced by the decreased expression of BiP, phospho-IRE1α, phospho-eIF2α, CHOP, ATF-6 and spliced X-box binding protein-1 in vitro and in vivo. UDCA or 4-PBA prevented hyperglycemia-induced or high glucose (HG)-induced apoptosis in podocytes in vivo and in vitro via the inhibition of caspase-3 and caspase-12 activation. Autophagy deficiency was also seen in glomeruli in diabetic mice and HG-incubated podocytes, exhibiting decreased expression of LC3B and Beclin-1, which could be restored by UDCA or 4-PBA treatment. Taken together, our results have revealed an important role of ER stress in the development of DN, and UDCA or 4-PBA treatment may be a potential novel therapeutic approach for the treatment of DN.

HuangQi Decoction Ameliorates Renal Fibrosis via TGF-ß/Smad Signaling Pathway In Vivo and In Vitro.

OBJECTIVE: Traditional Chinese Medicine compound HuangQi decoction is widely used in clinical treatment of chronic kidney disease, but its role on renal interstitial fibrosis and the underlying mechanism remains unclear. The aim of this study is to investigate the effect of HuangQi decoction on renal interstitial fibrosis and its association with the TGF-ß/Smad signaling pathway Methods: A total of 120 C57/BL mice were randomly divided into six groups: sham group, sham plus high-dose HuangQi decoction (1.08g/kg) group, unilateral ureteral obstruction (UUO) model group, and UUO model plus low to high doses of HuangQi decoction (0.12g/kg, 0.36g/kg and 1.08g/kg respectively) groups. Animals were sacrificed 14 days after the administration and ipsilateral kidney tissue was sampled for pathologic examinations. Immunohistochemistry, PCR and western blot were used to detect the expressions of related molecules in the TGF-ß/Smad signaling pathway. TGF-ß1 was used in in vitro experiments to induce human kidney proximal tubule epithelial cells (HK2). RESULTS: HuangQi decoction improved ipsilateral kidney fibrosis in UUO mice and downregulated the expressions of TGF-ß1, TßRI, TßRII, Smad4, Smad2/3, P-Smad2/3, α-SMA, collagen type I, III and IV in a dose-dependent manner while upregulated the expression of Smad7 in the same fashion. Similar results were found in in vitro studies. CONCLUSION: The protective effect of HuangQi decoction for unilateral ureteral obstruction kidney damage in mice was mediated by downregulating the TGF-ß/Smad signaling pathway.

HuangQi Decoction Improves Renal Tubulointerstitial Fibrosis in Mice by Inhibiting the Up-Regulation of Wnt/ß-Catenin Signaling Pathway.

OBJECT: To explore the effects of HuangQi decoction on tubulointerstitial fibrosis in mice and the Wnt/ß-catenin signaling pathway. METHODS: Unilateral ureteral obstruction (UUO) model was used. A total of 120 C57/BL mice were randomly divided into 6 groups, sham group, sham+HuangQi decoction group (1.08 g/kg), UUO group, UUO+HuangQi decoction group (0.12, 0.36, 1.08 g/kg). Immunohistochemical analysis, RT-PCR and Western blot were employed to examine the proteins and genes related to the Wnt/ß-catenin signaling pathway. RESULTS: In UUO mice models, expression levels of Wnt3,4, Frizzled4, LRP5,6, ß-catenin, LEF-1, TCF-1, Snail, MMP2,7 genes were positively correlated with the degree of renal tubulointerstitial fibrosis, while expression levels of GSK-3ß, Axin, APC, CK1 were negatively correlated. HuangQi decoction could down-regulate expression levels of Wnt3,4, Frizzled4, LRP5,6, ß-catenin, LEF-1, TCF-1, Snail, Twist, MMP2,7 and up-regulate expression levels of GSK-3ß, Axin, APC, CK1 and E-cadherin. CONCLUSION: HuangQi decoction could effectively inhibit the up-regulation of Wnt/ß-catenin signaling pathway induced by UUO, implying a possible role in improving renal interstitial fibrosis.

Ras/ERK signaling pathway is involved in curcumin-induced cell cycle arrest and apoptosis in human gastric carcinoma AGS cells.

Curcumin, the biologically active compound from the rhizome of Curcuma longa, could inhibit cell growth and induce apoptosis in gastric carcinoma. However, the underlying mechanism of curcumin on gastric carcinoma cells still needs further investigation. In this study, morphological observation indicated that curcumin inhibited the proliferation of AGS cells in a dose-dependent manner. According to the flow cytometric analysis, curcumin treatment resulted in G2/M arrest in AGS cells, accompanied with an increased expression of cyclin B1 and a decreased expression of cyclin D1. In addition, DNA ladders were observed by gel electrophoresis. Meanwhile, the activities of caspase-3, -8, and -9 were also enhanced in curcumin-treated AGS cells. Nevertheless, the increased activities could be inhibited by benzyloxycarbonyl-Val-Ala-Asp (OME)-fluoromethylketone (z-VAD-fmk), which suggested that the apoptosis was caspase-dependent. Furthermore, downregulation of rat sarcoma (Ras) and upregulation of extracellular-signal-regulated kinase (ERK) were also observed in AGS cells treated with curcumin by Western blot. U0126, an ERK inhibitor, blocked curcumin-induced apoptosis. The results suggested that curcumin inhibited the growth of the AGS cells and induced apoptosis through the activation of Ras/ERK signaling pathway and downstream caspase cascade, and curcumin might be a potential target for the treatment of gastric carcinoma.

Airway hyperresponsiveness induced by repeated esophageal infusion of HCl in guinea pigs.

Gastroesophageal reflux is a common disorder closely related to chronic airway diseases, such as chronic cough, asthma, chronic bronchitis, and chronic obstructive disease. Indeed, gastroesophageal acid reflux into the respiratory tract causes bronchoconstriction, but the underlying mechanisms have still not been clarified. This study aimed to elucidate functional changes of bronchial smooth muscles (BSMs) isolated from guinea pigs in an animal model of gastroesophageal reflux. The marked airway inflammation, hyperresponsiveness and remodeling were observed after guinea pigs were exposed to intraesophageal HCl infusion for 14 days. In addition, contractile responses to acetylcholine (ACh), KCl, electrical field stimulation, and extracellular Ca(2+) were greater in guinea pigs infused with HCl compared with control groups. The L-type voltage-dependent Ca(2+) channels (L-VDCC) blocker, nicardipine, significantly inhibited ACh- and Ca(2+)-enhanced BSM contractions in guinea pigs infused with HCl. The Rho-kinase inhibitor, Y27632, attenuated ACh-enhanced BSM contractions in guinea pigs infused with HCl. Moreover, mRNA and protein expressions for muscarinic M2 and M3 receptors, RhoA, and L-VDCC in BSM were detected by real-time PCR and Western blot. Expressions of mRNA and protein for muscarinic M3 receptors, RhoA, and L-VDCC were greater than in BSM of HCl-infused guinea pigs, whereas levels of muscarinic M2 receptors were unchanged. We demonstrate that acid infusion to the lower esophagus and, subsequently, microaspiration into the respiratory tract in guinea pigs leads to airway hyperresponsiveness and overactive BSM. Functional and molecular results indicate that overactive BSM is the reason for enhancement of extracellular Ca(2+) influx via L-VDCC and Ca(2+) sensitization through Rho-kinase signaling.

Antiproliferative effects of essential oil of a compound Chinese herbal medicine Weiqi Decoction on AGS cells.

OBJECTIVE: The main ingredients and the inhibitory effects of essential oil of a compound Chinese herbal medicine Weiqi Decoction (WQD) on AGS cell proliferation were to be investigated. METHODS: Chemical compounds of WQD essential oil were detected by gas chromatography and mass spectrometry analysis. Cell viability was measured by methyl thiazolyl tetrazolium method. Cell cycle distribution was detected by flow cytometry. Apoptosis and necrosis of AGS cells were determined by Hoechst 33342/propidium iodine staining. RESULTS: Chemical analysis showed that the main ingredients of WQD essential oil were bornylene and 3-n-butylphthalide. Ligustilide, which is the effective compound of Danggui (Radix Angelicae Sinensis), was not detected in WQD essential oil. The essential oil inhibited cell proliferation in a dose- and time-dependent manner, and blocked cell cycle progression at G(2)/M stage. At the concentrations that resulted in significant inhibition of cell proliferation and cell cycle arrest, essential oil induced both apoptosis and necrosis. CONCLUSION: The results suggest that WQD essential oil contains some effective ingredients for treating chronic atrophic gastritis and functional dyspepsia, and also has an antiproliferative effect on AGS cells through cell cycle arrest and apoptosis promotion in vitro. Therefore, essential oil should be retained as much as possible during stewing this decoction.

Astragaloside IV prevents endothelial dysfunction by improving oxidative stress in streptozotocin-induced diabetic mouse aortas.

Oxidative stress serves a role in endothelial dysfunction exhibited by patients with diabetes mellitus. Astragaloside IV (AS-IV) is a major active ingredient of Radix Astragali, which is considered to exhibit vasoprotective effects through unknown mechanisms. Thus, the current study was performed to investigate the protective effects of AS-IV in streptozotocin (STZ)-induced endothelial dysfunction and to explore whether antioxidant mechanisms were involved. The protective effects of AS-IV on the endothelium-dependent relaxation and contraction of aortic rings were determined by isometric tension recordings. NADPH subunits and endothelial nitric oxide synthase (eNOS) expression was identified via western blotting. Superoxide dismutase and malondialdehyde levels were assayed using ELISA. Furthermore, the generation of reactive oxygen species (ROS) and nitric oxide (NO) was detected via dihydroethidium and 4,5-diaminofluorescein diacetate staining, respectively. The results revealed that STZ-injected mice exhibited increased aortic endothelium-dependent vasoconstriction and decreased vasorelaxation to acetylcholine. However, AS-IV treatment reversed these effects. NG-nitro-L-arginine was subsequently used to completely inhibit impaired relaxation. Accordingly, impaired NO generation was restored following AS-IV treatment by increasing eNOS phosphorylation levels. Furthermore, ROS formation was also depressed following AS-IV treatment compared with that in STZ-injected mice. AS-IV also decreased the expression of various NADPH subunits, including human neutrophil cytochrome b light chain, neutrophil cytosolic factor 1, NADPH oxidase (NOX)2, NOX4 and Rac-1. The results of the current study may provide novel evidence that diabetes-induced vascular injury arises from either the inhibition of eNOS or the activation of NOX-derived ROS generation. In addition, the results warrant further investigation into the application of AS-IV treatment, leading to the improvement of oxidative stress, in patients with diabetes exhibiting endothelial dysfunction.

You-gui Pill ameliorates renal tubulointerstitial fibrosis via inhibition of TGF-ß/Smad signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: You-gui Pill (YGP), a traditional Chinese medicinal prescription, was widely used to warm and recuperate "kidney-yang" clinically for hundreds of years in China. Recent studies found that YGP had a potential benefit for renoprotection. AIM OF THE STUDY: The present study aimed to elucidate the in vivo and in vitro efficacy of YGP on renal tubulointerstitial fibrosis, and the molecular mechanism is also investigated. MATERIALS AND METHODS: Rat renal tubulointerstitial fibrosis model was elicited by unilateral ureteral obstruction (UUO). Sprague-Dawley rats underwent UUO and were studied after 14 days. Animals were randomly subjected to six groups: sham, UUO, UUO/YGP (0.14, 0.42, 1.26g/kg/d), and UUO/enalapril (10mg/kg/d). HE, Masson and ELISA were used for evaluate renal injury and function. Immunohistochemical analysis and western blot were used to detect the expressions of α-SMA, fibronectin, collagen matrix and Smads. In vitro studies were investigated in TGF-ß1-stiumlated NRK-49F cell line. RESULTS: Oral administration of YGP significantly decreased UUO-induced inflammatory cell infiltration, tubular atrophy and interstitial fibrosis, and there was no significant difference between YGP at 1.26g/kg and enalapril at 10mg/kg treatment (P>0.05). Meanwhile, serum creatinine and blood urea nitrogen levels were reduced dramatically (P<0.01). In coincide with the decreased of TGF-ß1, α-SMA, fibronectin and collagen matrix expressions were also declined with YGP treatment in both UUO kidneys and TGF-ß1-stimulated NRK-49F cell line. Additionally, nuclear translocation of p-Smad2/3 was markedly down-regulated by YGP (P<0.001), with a relative mild up-regulated expression of Smad7 (P<0.05). CONCLUSIONS: Our findings demonstrate that YGP had a renoprotective effect in ameliorating renal tubulointerstitial fibrosis, and this activity possibly via suppression of the TGF-ß and its downstream regulatory signaling pathway, including Smad2/3.

Synergistic Effect of Zuo Jin Wan on DDP-Induced Apoptosis in Human Gastric Cancer SGC-7901/DDP Cells.

A traditional Chinese medicine (TCM) formula, Zuo Jin Wan (ZJW), has been found as an anticancer drug in human cancer. In this study, we investigated the synergistic effect of ZJW extracts on DDP-induced apoptosis in human gastric cancer SGC-7901/DDP cells. Our results demonstrated that ZJW extracts could increase the sensitivity of SGC-7901/DDP cells to DDP by increasing the concentration of DDP in cytoplasm and enhance the proapoptosis of DDP by upregulating the JNK and Bax expression, downregulating the Bcl-2 expression, increasing the accumulation of Cytochrome C in cytoplasm, and promoting the activities of caspase-3 and caspase-9. In vivo, ZJW extracts enhanced the inhibiting effect of DDP on tumor growth in SGC-7901/DDP xenograft model and upregulated the expression of p-JNK and Bax but downregulated the Bcl-2 expression in xenograft tumors. In conclusion, in vitro and in vivo, ZJW extracts could enhance the proapoptotic effect of DDP by promoting the activation of JNK and the expression of Bcl-2, inhibiting the Bax expression, followed by increasing the release of Cytochrome C from mitochondria to cytoplasm, and finally activating the caspase cade reaction. Our results implied that ZJW might serve as a synergistic drug with chemotherapeutic drugs DDP in the treatment of gastric cancer.