Docetaxel sale br Materials and methods br Results br Discus

Materials and methods
Results
Discussion Both EMT of the tubular epithelial Docetaxel sale and the activation of fibroblasts are critical factors in the pathogenesis and progression of renal interstitial fibrosis. Accumulating evidence implicates EMT in the onset and pathogenesis of renal interstitial fibrosis [11,12]. The process of EMT is characterized by a loss of epithelial cell markers like E-cadherin, and a gain of mesenchymal features like α-SMA and vimentin [9,45]. This process occurs after excessive exposure to multiple factors including hypoxia, reactive oxygen species, and numerous profibrotic cytokines and growth factors [9,13,46]. Although many cytokines are involved in initiating EMT, TGF-β1 is known as the vital inducement that triggers the process of EMT [8,46,47]. It is sufficient to induce EMT in nonmalignant and malignant epithelial cells in vitro. It is considered a major factor promoting EMT in invasive and metastatic cancers in vivo [48]. Meanwhile, the activation of renal interstitial fibroblasts and overproduction of ECM proteins are considered to be pivotal events in the pathogenesis of chronic renal fibrosis [40]. Fibroblasts activated by TGF-β1 and EMT-derived fibroblast-like cells differentiate into myofibroblasts and elevate the production of the major ECM proteins in fibrotic tissues [43,44]. It has been shown that there is an increase in both HDAC1 and HDAC2 in the tubular epithelium following UUO [41]. Our results showed that FK228 reduced the level of HDAC1 and HDAC2 in the process of exerting its effects with respect to renal interstitial fibrosis. Meanwhile, the acetylation of histone H3 increased during treatment with FK228. In this study, we also found that FK228 inhibited the expression of target gene induced by TGF-β1, including inflammatory cytokines and ECM proteins. Importantly, we found that FK228 remarkably inhibited TGF-β1-induced EMT through Smad, ERK, and P38 MAPK signaling pathways in rat tubular epithelial cells. Furthermore, we showed that FK228 significantly inhibited the activation and proliferation of renal interstitial fibroblasts, which serve an important role in the production of ECM proteins. We showed that treatment with FK228 markedly inhibited the production of Cyclin D1 in NRK-49F cells. Furthermore, FK228 largely elevated the expression of P21 and P27. Therefore, FK228 may be able to block renal fibroblasts in the G0/G1 phase of the cell cycle via inhibition of Cyclin D1. This process is mediated by cyclin-dependent kinase (CDK) and is required to stimulate the downstream expression of E2F target genes that drive the G1-to-S transition. Although several studies have shown that HDACi blocks cell cycle progression in cancer cells [74,75], this effect has not been formerly reported in renal fibroblasts. Among cancer cells, a major mechanism for the antiproliferative effects of HDACi involves upregulation of the expression of CDK inhibitors P21 and P27 [[75], [76], [77], [78], [79]]. P21 and P27 inhibit the activity of the Cyclin D1/CDK4/6 complexes, thus preventing the phosphorylation of retinoblastoma protein (Rb), which is required to promote the transition from G1 to the S phase of the cell cycle. In our study, the upregulation of P21 and P27 inhibited the activity of the Cyclin D1/CDK4/6 complexes in NRK-49F cells, which blocked the transition from G1 to the S phase of the cell cycle. So we thought FK228 may inhibited the cell cycle of NRK-49F cells. The results were consistent with FK228 suppressed the proliferation of renal fibroblasts and promoted its apoptosis. However, the accumulations of fibroblasts were reduced in the UUO kidneys treated with FK228 to inhibit renal fibrosis.
Conclusions
Contributions
Disclosure
Acknowledgements
Introduction Cux1 is the murine homologue of the Drosophila gene Cut (Nepveu, 2001; Vanden Heuvel et al., 1996). Mammalian homologues of Cut have also been identified in human, dog, and rat (Sansregret and Nepveu, 2008; Gupta et al., 2003). In Drosophila, Cut is required for the development of the Malpighian tubules, which serve as primitive kidneys and function as the excretory organs in these insects (Gupta et al., 2003). In the mouse kidney, Cux1 is highly expressed in the nephrogenic zone, which is a region characterized by actively proliferating cells (Vanden Heuvel et al., 1996). Cux1 downregulation is associated with cell cycle exit and terminal differentiation of nephron progenitor cells (Vanden Heuvel et al., 1996).