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We developed a 3D glomeruli tissue chip for glomerulonephritis (GN) testing, featuring a gravity-driven glomerular filtration barrier (GFB) with human podocytes and endothelial cells with a bidirectional flow in the bottom channel. Using puromycin-induced GN, we observed decreased cell viability, increased albumin permeability, and reduced WT1 and nephrin compared to the normal GFB. Tacrolimus restored cell viability, reduced albumin permeability, and increased WT1 expression. Using serum from five membranous nephropathy (MN) patients, we created MN models using a GFB-mimicking chip. A notable decline in cell viability was observed in the serum-induced MN1 and MN2 models. However, tacrolimus restored it. Albumin permeability was reduced in the MN1, MN2, and MN5 models by tacrolimus treatment. MN1 displayed the best clinical response to tacrolimus, exhibiting increased expression of WT1 in chip-based evaluations after tacrolimus treatment. We successfully evaluated the efficacy of tacrolimus using puromycin-induced and serum-induced GN models on a chip that mimicked the structure and function of the GFB. The GFB-mimicking chip holds promise as a personalized platform for assessing drug efficacy using patient serum samples. [ABSTRACT FROM AUTHOR]

The E2F1 transcription factor can promote proliferation or apoptosis when activated, and is a key downstream target of the retinoblastoma tumour suppressor protein (pRB). Here we show that E2F1 is [...]

GI cyclin-dependent kinases have been found to be not sufficient to reverse dE2F2-mediated repression. Repression that is dE2F2 mediated is different from retinoblastoma family protein 1 (RBF1) inhibition of dE2FI. It is resistant to CycE/cdk2 and Cyclin D/cyclin-dependent kinase 4 (CycD/cdk4). To study these things e ither DAP, the Drosophila homolog of p21, or dE2F2, the repressor E2F, was inactivated in cells without dE2F1.

SIRT1 is a NAD-dependent protein deacetylase that participates in cellular regulation. The increased migration of fibroblasts is an important phenotype in fibroblast activation. The role of SIRT1 in cell migration remains controversial as to whether SIRT1 acts as an activator or suppressor of cell migration. Therefore, we have established the role of SIRT1 in the migration of human dermal fibroblasts and explored targets of SIRT1 during dermal fibroblast migration. SIRT1 and Cyr61 were expressed in human dermal fibroblasts and the stimulation with TGF-β further induced their expression. Treatment with resveratrol (RSV), a SIRT1 agonist, or overexpression of SIRT1 also promoted the expression Cyr61 in human dermal fibroblasts, whereas the inhibition of SIRT1 activity by nicotinamide or knockdown of SIRT1 decreased the level of Cyr61, as well as TGF-β or RSV-induced Cyr61 expression. Blocking of ERK signaling by PD98509 reduced the expression of Cyr61 induced by TGF-β or RSV. TGF-β, RSV, or SIRT1 overexpression enhanced β-catenin as well as Cyr61 expression. This stimulation was reduced by the Wnt inhibitor XAV939. RSV increased migration and nicotinamide attenuated RSV-induced migration of human dermal fibroblasts. Furthermore, SIRT1 overexpression promoted cell migration, whereas blocking Cyr61 attenuated SIRT1-stimulated migration of human dermal fibroblasts. SIRT1 increased cell migration by stimulating Cyr61 expression and the ERK and Wnt/β-catenin signaling. SIRT1-induced Cyr61 activity is very important for human dermal fibroblasts migration. [ABSTRACT FROM AUTHOR]

Aim Peroxisome proliferator-activated receptor gamma ( PPARγ) agonists have anti-inflammatory properties that reduce inflammatory cytokine production in rheumatoid arthritis ( RA). Cysteine-rich angiogenic inducer 61 (Cyr61) is associated with diseases related to chronic inflammation. The aim of this study was to investigate the mechanisms underlying the effects of PPARγ agonists on tumor necrosis factor ( TNF)-α-induced fibroblast-like synoviocyte ( FLS) invasion and migration, as well as Cyr61 production, in RA- FLS. Methods FLS were cultured with TNF-α and Cyr61 in the presence or absence of PPARγ agonists. Matrix metalloproteinase and Cyr61 expression levels in RA- FLS and culture supernatants were measured by reverse transcriptase-polymerase chain reaction ( RT- PCR) and Western blotting. The migration and invasion phenotypes of RA- FLS were determined by wound healing and Boyden chamber assays. Results Cyr61 protein was expressed in RA- FLS, and its intracellular expression and secretion levels were increased by TNF-α. Moreover, Cyr61 directly promoted RA- FLS migration and invasion. Rosiglitazone ( RSG) significantly decreased TNF-α-induced Cyr61 expression. RSG decreased TNF-α-induced nuclear factor ( NF)-κB activation and inhibitor of κBα degradation. Furthermore, RSG inhibited TNF-α-induced RA- FLS migration and invasion and decreased Cyr61 treatment-induced RA- FLS invasion. Finally, blocking Cyr61 significantly attenuated TNF-α-induced migration. Conclusions Our results demonstrate for the first time that PPARγ agonists may have beneficial effects on the migration and invasion of RA- FLS via the downregulation of Cyr61. Therefore, PPARγ agonists could be potential treatment targets for RA. [ABSTRACT FROM AUTHOR]