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Oxidative stress and inflammation are involved in the pathogenesis in renal ischemia/reperfusion (I/R) injury. It has been demonstrated that polydatin processed the antioxidative, anti-inflammatory, and nephroprotective properties. However, whether it has beneficial effects and the possible mechanisms on renal I/R injury remain unclear. In our present study I/R models were simulated bothin vitroandin vivo. Compared with vehicle control, the administration of polydatin significantly improved the renal function, accelerated the mitogenic response and reduced cell apoptosis in renal I/R injury models, strongly suppressed the I/R-induced upregulation of the expression of tumor necrosis factor-α, interleukin-1β, cyclooxygenase-2, inducible nitric oxide synthase, prostaglandin E-2, and nitric oxide levels, and dramatically decreased contents of malondialdehyde, but it increased the activity of superoxide dismutase, glutathione transferase, glutathione peroxidase and catalase, and the level of glutathione. Further investigation showed that polydatin upregulated the phosphorylation of Akt in kidneys of I/R injury dose-dependently. However, all beneficial effects of polydatin mentioned above were counteracted when we inhibited PI3K/Akt pathway with its specific inhibitor, wortmannin. Taken together, the present findings provide the first evidence demonstrating that PD exhibited prominent nephroprotective effects against renal I/R injury by antioxidative stress and inflammation through PI3-K/Akt-dependent molecular mechanisms.

As one of the quenched and tempered steels, 40Cr steel is often used to manufacture the shaft in heavy-duty trucks. To adjust the working environment of the heavy-duty machines, 40Cr steel should have high impact property. In this study, different tempering cooling mediums were treated as critical influence on improving impact property of the steel. After heated under 520°C tempering temperature, the samples of 40Cr were cooled in air, oil and water, respectively. The experiments were carried out through charpy impact, metallographical and SEM analysis. The results has shown that 40Cr steel of high impact property and fine microstructure can be obtained when water is used for the tempering cooling medium.

The effect of different tempering temperatures on microstructure and impact property of 20CrMnTi steel has been studied on Zwick/roell Amsler PKP 450 pendulum machine, SU-8020 scanning electron microscope (SEM) and optical microscope. The results shows that the impact property of 20CrMnTi steel is dramatically improved after high-temperature tempering. However, the minimum value occurs when it was tempered at 350°C because of low-temperature tempering brittlement at this degree. The SEM fracture morphology was typical dimples after high temperature tempering, and the type of fracture was ductile fracture; the type of cleavage characteristic and quasi cleavage characteristic were generated on the fracture morphology at low-temperature and medium-temperature tempering respectively, and the type of fracture was brittle.

40Cr is a kind of steel that is often used for semiaxis in heavy duty trucks, therefore high impact property of 40Cr steel is requested to adjust the heavy-duty machines working environment. In this study, the samples of 40Cr steel were heated under normal tempering temperature and quenched in air, water and oil, respectively. The experiments were carried out through charpy impact and microhardness analysis. It was indicated by experiments that water was more helpful to receive higher impact toughness as the tempering cooling medium than air and oil. At the same time, the intensity and hardness of 40Cr steel were enough to meet the heavy-duty machine semiaxis requirements.

Polydatin, a glucoside of resveratrol, recently has been demonstrated possibly to exert its biological effects by targeting sonic hedgehog (Shh). However, whether Shh signaling pathway is involved in the therapeutic effects of polydatin for renal ischemia/reperfusion (I/R) injury has not been evaluated. Our results showed that I/R induced the secretion of Shh, upregulated Patched and Smoothened, and enhanced the nuclear translocation and target gene transcription of Glioblastoma 1 in renal I/R injury models, which were further upregulated after the administration of polydatin significantly and in turn exerted prominent nephroprotective effects against cell apoptosis and oxidative stress. The treatment with cyclopamine (a specific inhibitor of Smoothened) or 5E1 (an anti-Shh antibody) not only markedly inhibited the activation of the Shh pathway, but also dramatically suppressed the nephroprotective effects of polydatin above-mentioned. These results advance our knowledge that polydatin can provide protection for kidneys against I/R injury by enhancing antioxidant capacity and decreasing cell apoptosis through activating Shh signaling pathway.

Bcrp1/ABCG2 is exclusively expressed in side population (SP) cells, however, it has not been fully elucidated whether it has an impact on the viability, proliferation and paracrine actions in kidney SP cells under oxygen-glucose deprivation (OGD) followed by reoxygenation. In this study, we found that 2-h OGD did not injure SP cells (sub-lethal OGD) but induced SP cells proliferation 48 and 72 h after reoxygenation; whereas 4-h OGD markedly injured the cells (lethal OGD) and led to apoptosis 24-72 h after reoxygenation. Fumitremorgin C, an inhibitor of ABCG2, attenuated both the proliferation and viability of SP cells. Sub-lethal and lethal OGD induced the increase in the secretion of vascular endothelial growth factor, insulin-like growth factor 1, hepatocyte growth factor, and stromal cell-derived factor-1α in kidney SP cells, which was inhibited by Fumitremorgin C. Collectively, these findings provide evidence for a crucial role for the ABCG2 expression in the viability, proliferation and paracrine actions of kidney SP cells after OGD.

Purpose: The aim of this study was to establish an in vitro method to purify human multipotent adult progenitor cells (hMAPCs) and assess their possible differentiation into hepatocytes by coculture with human hepatocyte line L02. Methods: hMAPCs were isolated by magnetic activated cell sorting (MACS) depletion selection using CD45 and GlyA microbeads. After indirect or direct coculture of hMAPCs and human hepatocyte line L02, the expression of albumin (ALB), alpha-fetoprotein (AFP), cytokeratin (CK) 18, and CK19 by hMAPCs was detected by immunocytochemistry. Results: With the MACS method, (5?10) × 10⁴/mL hMAPCs could be separated from 1 × 10?/mL bone marrow mononuclear cells. The purity of CD45-/GlyA- cells separated from bone marrow adherent cells was more than 98%, as determined by flow cytometry. In the coculture without cell-to-cell contact, hMAPCs expressed high AFP on day 1, and then tapered daily to low expression on day 7; ALB expression reached its peak on day 5, and remained high on day 7; CK18 was initially expressed on day 5 and was higher on day 7; CK19 was negative in all assays. In the coculture with cell-to-cell contact, ALB and CK18 were expressed by most cells while AFP appeared in only a few on day 5. Conclusion: hMAPCs were induced to differentiate into mature hepatocyte-like cells by coculture with a hepatocyte cell line, either with or without cell-to-cell contact, but the former seemed more effective.