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Obstructive uropathy is a common kidney disease caused by elevated hydrostatic pressure (HP), but relevant molecular and cellular mechanisms have not yet been well understood. In this study, we ex vivo investigated the effects of elevated HP on human renal epithelial cells (HREpCs). Primary HREpCs were subjected to 100 cmH2O HP for 8 or 48 h. Then, the cells were cultured without HP stimulation for another 24 h or 72 h. Cell morphology showed almost no change after 8h HP treatment, but exhibited reversible elongation after 48h HP treatment. HP treatment for 8 h increased the expression of TGFB1 and VEGFA but decreased the expression of CSF2 and TGFB2. On the other hand, HP treatment for 48 h downregulated the expression of CSF2, TGFB2, PDGFB, VEGFA, and VEGFB, while upregulated the expression of TGFB3. Interestingly, all changes induced by 48 h HP treatment were detected more severe compared to 8 h HP treatment. In conclusion, elongated ex vivo HP loading to renal epithelial cells induces reversible changes on cell morphology and disturbs the expression of several growth factors, which provides novel mechanistic insight on elevated HP-caused kidney injury such as obstructive uropathy. [ABSTRACT FROM AUTHOR]

Inflammation-induced activation and dysfunction of endothelial cells play an important role in the pathology of multiple vascular diseases. Nicaraven, a potent hydroxyl radical scavenger, has recently been found to have anti-inflammatory roles; however, the mechanism of its action is not fully understood. Here we investigated the effects of Nicaraven on tumor necrosis factor [alpha] (TNF[alpha])-induced inflammatory response in human umbilical vein endothelial cells and we explore the underlying mechanisms related to the nuclear factor-[kappa]B (NF-[kappa]B) signaling pathway. Our results showed that Nicaraven significantly reduced the reactive oxygen species production after TNF[alpha] stimulation. Nicaraven suppressed TNF[alpha]-induced mRNA expression of multiple adhesion molecules and proinflammatory cytokines, including vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1), E-selectin, MCP-1, TNF[alpha], interleulon-1[beta] (IL-1[beta]), IL-6, and IL-8. In addition, Nicaraven inhibited monocyte adhesion and reduced the protein levels of VCAM-1 and ICAM-1. Mechanistically, Nicaraven prevented TNF[alpha]-induced activation of NF-[kappa]B signaling pathway by suppressing the phosphorylation of NF-[kappa]B p65, I[kappa]B[alpha], and I[kappa]B kinase (IKK)[alpha]/[beta], stabilizing I[kappa]B[alpha], and inhibiting the translocation of p65 from cytosol to nucleus. Finally, we showed that Nicaraven improved the functions of endothelial cells, seen as the upregulation of endothelial nitric oxide synthase and increased nitric oxide levels. Our findings indicated that Nicaraven effectively inhibits TNF[alpha] -induced endothelial activation and inflammatory response at least partly through inhibiting NF-[kappa]B signaling pathway. Key words: endothelial cells, Nicaraven, inflammation, TNF[alpha], nuclear factor-[kappa]B. L'activation et le dysfonctionnement des cellules endotheliales engendres par l'inflammation jouent un role important dans la pathologie de multiples maladies vasculaires. On a recemment observe que le nicaravene, un puissant piegeur des radicaux hydroxyl, joue des roles anti-inflammatoires. Toutefois, on ne comprend pas entierement son mode d'action. Nous avons etudie ici les effets du nicaravene sur les reactions inflammatoires provoquees par le TNF[alpha] dans des cellules endotheliales de veine ombilicale humaine et explore les modes d'action sous-jacents lies a la voie de signalisation du facteur NF-[kappa]B. Nos resultats ont montre que le nicaravene permet de faire diminuer de facon marquee la production de derives reactifs de l'oxygene apres une stimulation par le TNF[alpha]. Le nicaravene permettait d'inhiber completement l'expression en ARNm de multiples molecules d'adherence et cytokines proinflammatoires engendree par le TNF[alpha], y compris VCAM-1, ICAM-1, l'E-selectine, MCP-1, TNF[alpha], IL-1[beta], IL-6 et IL-8. De plus, le nicaravene permettait d'inhiber l'adherence des monocytes et de faire diminuer les taux en proteines de VCAM-1 et de ICAM-1. Du point de vue des mecanismes, le nicaravene permettait de prevenir l'activation de la voie de signalisation du facteur NF-[kappa]B engendree par le TNF[alpha] par l'intermediaire de l'inhibition complete de la phosphorylation de NF-[kappa]B p65, d'I[kappa]B[alpha] et d'IKK[alpha]/[beta], de la stabilisation de l'I[kappa]B[alpha] et de l'inhibition de la translocation de p65 du cytosol vers le noyau. Enfin, nous avons montre que le nicaravene permet d'ameliorer le fonctionnement des cellules endotheliales, amelioration observee par la regulation a la hausse de l'oxyde nitrique synthase endotheliale ainsi que par l'augmentation des taux d'oxyde nitrique. Nos resultats montraient que le nicaravene permet d'inhiber efficacement l'activation et la reaction inflammatoire de l'endothelium provoquees par le TNF[alpha], au moins en partie par l'intermediaire de l'inhibition de la voie de signalisation du facteur NF-[kappa]B. [Traduit par la Redaction] Mots-cles: cellules endotheliales, nicaravene, inflammation, TNF[alpha], NF-[kappa]B., Introduction Endothelial cells play an important role in systemic vascular homeostasis, and are the main target of circulating cells and humoral mediators under injury (Tousoulis et al. 2008). Therefore, they [...]

Biomechanical cue within the tissue microenvironment is known to play a critical role in regulating cell behaviors and maintaining tissue homeostasis. As hydrostatic pressure often increases in biliary system under pathological states, we investigated the effect of the moderate elevation of the hydrostatic pressure on biliary epithelial cells, especially on the epithelial-mesenchymal transition (EMT). Human intrahepatic biliary epithelial cells were loaded to hydrostatic pressure using a commercial device. We found that loading the cells to 50 mmHg hydrostatic pressure induced obvious morphological changes and significantly upregulated vimentin, ZEB1, and pSmad2/3, fibronectin, and collagen 1α. All changes induced by hydrostatic pressure loading were effectively mitigated by either ROCK inhibitor (Y-27632) or ALK5 inhibitor (SB-431542). Our in vitro experimental data suggests that hydrostatic pressure loading induces EMT of cholangiocytes through RhoA/ROCK and TGF-β/Smad pathways. Elevated hydrostatic pressure in biliary duct system under pathological states may promote the biliary epithelial cells shifting to profibrotic and mesenchymal characteristics. [ABSTRACT FROM AUTHOR]