Bufalin inhibits PDGF-BB-induced mesangial cell proliferation via mediating gap junctional intercellular communication / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the role and possible mechanisms of gap junctional intercellular communication (GJIC) involved in mesangial cell (MC) proliferation which could be inhibited by bufalin.</p><p><b>METHODS</b>Rat mesangial cells were cultured in vitro. The effect of bufalin on platelet-derived growth factor-BB (PDGF-BB)-induced MC proliferation was evaluated by MTT assay. The function of GJIC was detected by Lucifer Yellow scrape loading and dye transfer (SLDT). mRNA levels of Cx43, Cx45 and Cx40 were measured by RT-PCR. Intracellular calcium concentrations ([Ca(2+)]i) were examined in laser scanning confocal microscopy after loading by Fura-3/AM.</p><p><b>RESULTS</b>MTT indicated that bufalin could inhibited PDGF-BB-induced MC proliferation (P<0.01). Compared with the hormal control group, PDGF-BB inhibited GJIC function, increased the expression of Cx45 and Cx40 (P<0.01) without altering the Cx43 (P>0.05) in gene level and also increased [Ca(2+)]i. However, bufalin treatment enhanced GJIC function, decreased Cx45 mRNA and Cx40 mRNA expression (P<0.01), and reduced [Ca(2+)]i (P<0.01).</p><p><b>CONCLUSIONS</b>Bufalin inhibits PDGF-BB-induced MC proliferation, and its possible mechanisms may be related to regulation of Cx45 and Cx40 expression in the gene level, reduction of [Ca(2+)]i and enhancement of GJIC function.</p>

Effects of exogenous connective tissue growth factor on collagen III synthesis of human renal tubular epithelial cells / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To explore the role of exogenous connective tissue growth factor (CTGF) in the collagen III synthesis of human renal tubular epithelial cell line HK2 in vitro.</p><p><b>METHODS</b>Cultured HK2 cells were randomly assigned to three groups: placebo-control, low-dose CTGF-treated (2.5 ng/mL) and high-dose CTGF-treated groups (20 ng/mL). Cell morphological changes were observed under an inverted microscope. Collagen III alpha mRNA expression was detected using RT-PCR. Immunohistochemistry staining was used to assess the levels of intracellular collagen III alpha protein.</p><p><b>RESULTS</b>After 48 hrs of low- or high- dose CTGF treatment, the appearances of HK2 cells were changed from oval to fusiform. High-dose CTGF treatment increased collagen III alpha mRNA expression (0.4461+/-0.0274 vs 0.2999+/-0.0115; P<0.05) as well as the protein expression of collagen III alpha (0.4075+/-0.0071 vs 0.3503+/-0.0136; P<0.05) compared with the placebo-control group.</p><p><b>CONCLUSIONS</b>CTGF can induce morphological changes of human renal tubular epithelial cells in vitro. High concentration of CTGF may increase the synthesis of collagen III alpha.</p>

Transdifferentiation and collagen-synthesis effects of exogenous connective tissue growth factor on renal tubular epithelial cells in vitro / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the effects of recombinal human connective tissue growth factor (rhCTGF) stimulation on epithelial-myofibroblast transdifferentiation (EMT) and collagen-synthesis in human renal tubular epithelial cell line (HK2) in vitro.</p><p><b>METHODS</b>The cultured HK2 cells were stimulated with rhCTGF of 5 ng/mL. The morphological changes were observed under an inverted microscope. The cells were collected at 0, 3, 6, 12, 24 and 48 hrs after rhCTGF stimulation. The expression of E-cadherin,alpha-smooth muscle actin (alpha-SMA), collagen Ialpha1 (Col Ialpha1) and collagen IValpha1 (Col IValpha1) mRNAs were detected by RT-PCR.</p><p><b>RESULTS</b>rhCTGF stimulation changed the HK2 cell appearance from oval to fusiformdown-regulated the E-cadherin mRNA expression and up-regulated alpha-SMA mRNA expression, but had no effects the Col Ialpha1 and Col IValpha1 mRNA expression.</p><p><b>CONCLUSIONS</b>Exogenous CTGF can mediate the EMT but has no collagen-synthesis effects on HK2 cells.</p>