Molecular mechanisms of mycelium of Cordyceps sinensis ameliorating renal tubular epithelial cells aging induced by D-galactose via inhibiting autophagy-related AMPK/ULK1 signaling activation / 中国中药杂志

To explore the effects and molecular mechanisms of mycelium of Cordyceps sinensis(MCs)improving renal tubular epithelial cells aging induced by D-galactose,the renal proximal tubular epithelial cells(NRK-52E cells)of rats in vitro were divided into the normal group(N),the D-gal model group(D),the low dose of MCs group(L-MCs),the medium dose of MCs group(M-MCs)and the high dose of MCs group(H-MCs),and treated by the different measures,respectively.More specifically,the NRK-52E cells in each group were separately treated by 1%fetal bovine serum(FBS)or D-galactose(D-gal,100 mmol·L~(-1))or D-gal(100 mmol·L~(-1))+MCs(20 mg·L~(-1))or D-gal(100 mmol·L~(-1))+MCs(40 mg·L~(-1))or D-gal(100 mmol·L~(-1))+MCs(80 mg·L~(-1)).After the intervention for24 h or 48 h,firstly,the effects of D-gal on the protein expression levels of klotho,P27 and P16,the staining of senescence-associatedβ-galactosidase(SA-β-gal)and the activation of adenosine monophosphate activated protein kinase(AMPK)/uncoordinated 51-like kinase 1(ULK1)signaling in the NRK-52E cells were detected,respectively.Secondly,the effects of MCs on the activation of the NRK-52E cells proliferation were investigated,respectively.Finally,the effects of MCs on the protein expression levels of klotho,P27,P16and microtubule-associated protein 1 light chain 3(LC3),the staining of SA-β-gal and the activation of AMPK/ULK1 signaling in the NRK-52E cells exposed to D-gal were examined severally.The results indicated that,for the NRK-52E cells,D-gal could cause aging,induce the protein over-expression levels of the phosphorylated AMPK(p-AMPK)and the phosphorylated ULK1(p-ULK1)and activate AMPK/ULK1 signaling pathway.The co-treatment of MCs at the medium and high doses and D-gal could significantly ameliorate the protein expression levels of klotho,P27,P16 and the staining of SA-β-gal,suggesting the anti-cell aging actions.In addition,the cotreatment of MCs at the medium and high doses and D-gal could obviously improve the protein expression levels of LC3,p-AMPK,and p-ULK1,inhibit the activation of AMPK/ULK1 signaling and increase autophagy.On the whole,for the renal tubular epithelial cells aging models induced by D-gal,MCs not only has the in vitro actions of anti-aging,but also intervenes aging process by inhibiting autophagy-related AMPK/ULK1 signaling activation,which may be the novel molecular mechanisms of MCs protecting against aging of the renal tubular epithelial cells.

Influence of a large dam on the longitudinal patterns of fish assemblages in Qingyi Stream.

Using seasonally collected data (2009-2010) from 15 sampling sites that represent first- to fifth-order streams within the Qingyi watershed, we examined the spatio-temporal patterns of fish assemblages along two longitudinal gradients to explore the effects of a large dam on fish assemblages at the watershed scale. No significant variation was observed in either species richness or assemblage structure across seasons. Species richness significantly varied according to stream order and gradient. Dam construction appeared to decrease species richness upstream substantially, while a significant decrease between gradients only occurred within fourth-order streams. Along the gradient without the large dam, fish assemblage structures presented distinct separation between two neighboring stream orders, with the exception of fourth-order versus fifth-order streams. However, the gradient disrupted by a large dam displayed the opposite pattern in the spatial variation of fish assemblages related with stream orders. Significant between-gradient differences in fish assemblage structures were only observed within fourth-order streams. Species distributions were determined by local habitat environmental factors, including elevation, substrate, water depth, current discharge, wetted width, and conductivity. Our results suggested that dam construction might alter the longitudinal pattern in fish species richness and assemblage structure in Qingyi Stream, despite the localized nature of the ecological effect of dams.