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Objective:To explore the mechanism of mitochondrial apoptotic pathway in rat degenerative intervertebral disc cells in improving intervertebral disc degeneration under the action of Bushen Zhuangdu recipe. Method:The 100 SD male rats were randomly divided into blank group, model group, low, medium and high dose Bushen Zhuangdu recipe group (0.38,0.77,1.53 g·kg-1).Histopathological changes of rat intervertebral discs were observed by hematoxylin-eosin(HE) staining after 4 weeks of continuous administration of Chinese medicine. The apoptotic rate of nucleus pulposus cells in degenerative intervertebral discs was detected by TUNEL(terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling), and the levels of active Cysteinyl aspartate-specific proteinase-3(active Caspase-3), B cell leukemia-2(Bcl-2), cytochrome C (cytC) and Bcl-2-associated X protein(Bax) protein in intervertebral discs were detected by Western blot. Result:Compared with blank group, the histopathological score of intervertebral disc in the model group was significantly increased, the apoptosis rate of nucleus pulposus was significantly increased (PPPPPPConclusion:Bushen Zhuangdu recipe may improve the degeneration of intervertebral disc by reducing the expression of active Caspase-3, cytC and Bax, increasing the expression of Bcl-2 and inhibiting the apoptotic pathway of mitochondria in a dose-dependent manner.
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BACKGROUND: Numerous studies focus on animal models of intervertebral disc degeneration (IDD), but criteria for establishing the animal models of IDD have not been confirmed, and there is a lack of systematic comparison among models. OBJECTIVE: To compare the rat models of IDD established by puncturing at annulus, endplate injection and their combination, thus providing reference for IDD model selection. METHODS: Eighty Sprague-Dawley rats were equivalently randomized into four groups: puncturing group (puncturing at the annulus), endplate injection group (endplate injected with ethyl alcohol), combination group (puncturing at the L5-6annulus and endplate injection at the same segment) and sham operation group. Three rats in each group were taken at postoperative 4, 8, and 12 weeks for X-ray examination to measure the disc height; and the discs were removed for histological observation and immunohistochemical staining. RESULTS AND CONCLUSION: The results of X-ray examination, hematoxylin-eosin staining and immunohistochemical staining all showed that the IDD degree was gradually aggravated in all groups except the sham operation group. At postoperative 4 weeks, compared with the sham operation group, in the endplate injection and combination groups, the percent disc height was significantly decreased, the pathological scores were significantly increased and the average gray value of collagen type I was significantly reduced (P ＜ 0.05). At postoperative 8 and 12 weeks, compared with the sham operation group, the percent disc height in the other three groups were all significantly decreased, the pathological score was significantly increased, and the average gray value of collagen type I was significantly decreased (P ＜ 0.05). Compared with the puncturing and endplate injection group, in the combination group, the percent disc height at postoperative 8 weeks was significantly decreased, and the average gray value of collagen type I at postoperative 12 weeks was significantly decreased (P ＜ 0.05). These results suggest that the rat IDD model can be successfully constructed by above three methods. Puncturing at the annulus is easy to operate and control IDD progression, which can be used to study different stages of IDD. Endplate injection is suitable for the etiological study of IDD, and induces IDD earlier than puncturing, but the final results are similar. The combination method can significantly accelerate IDD aggravation, and thus is not time consuming.
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<p><b>OBJECTIVE</b>To study the biological impact and mechanism of recombinant tissue factor pathway inhibitor (rTFPI) on apoptosis of rat kidney mesangial cells (MsC).</p><p><b>METHODS</b>TFPI expression in human glomerular minor lesion (GML), mesangial proliferative glomerulonephritis (MPGN) and cultured rat MsC was detected using immunohistochemistry and immunofluorescence, respectively. Rat MsC were incubated with rTFPI and its variant peptides. Morphological changes of apoptosis were investigated by Hoechst 33258 and the apoptotic rate was assessed by flow cytometry. DNA fragmentation and effect of rTFPI on expression of caspase-3, Fas and bcl-2 were studied using gel electrophoresis and Western blot respectively.</p><p><b>RESULTS</b>The expression of TFPI in MPGN was higher than that in GML. TFPI was expressed in cultured rat mesangial cells. Apoptosis of MsC was induced by rTFPI, especially by its C-termianl, in a dose- and time-dependent manner. Apoptosis ratios of MsC treated with rTFPI were 2.1, 3.0 and 4.9 times more than control, respectively. Expression of gene caspase-3 and Fas was up-regulated in a dose-dependent manner wherease bcl-2 expression did not show any changes.</p><p><b>CONCLUSION</b>rTFPI induces apoptosis in cultured rat mesangial cells by its C-terminal possibly via Fas/FasL pathway.</p>
Subject(s)
Animals , Humans , Rats , Apoptosis , Physiology , Caspase 3 , Metabolism , Cells, Cultured , DNA Fragmentation , Flow Cytometry , Lipoproteins , Metabolism , Pharmacology , Mesangial Cells , Cell Biology , Metabolism , Peptides , Pharmacology , bcl-Associated Death Protein , Metabolism , PharmacologyABSTRACT
<p><b>OBJECTIVE</b>To study the effects of aldose reductase (AR) on the proliferation of rat mesangial cells (MsC) in vitro and to investigate its mechanism.</p><p><b>METHODS</b>Cell proliferation was assessed by MTT colorimetric assay. Cell cycle and apoptosis were analyzed by flow cytometry. The growth of normal MsC and AR transfected MsC was compared. The proliferation of PDGF-BB and cellular growth stimulation by 10% NBS were investigated using AR inhibitors (ARI) Sorbinil and Zopolrestat. The effects of PDGF-BB on the expression of AR, p65 and c-Jun were assessed by Western blot. Activation of AP-1 was measured by EMSA.</p><p><b>RESULTS</b>AR expression of transfected MsC was distinctly higher than that of the control. Transfected MsC grew quicker than normal cells. ARI partially inhibited the proliferation of transfected MsC under the stimulation of PDGF-BB and 10% NBS, whereas 10% NBS had no effect on normal MsC. PDGF-BB upregulated the expression of AR and c-Jun, but had no effect on p65. The upregulation of c-Jun and the activation of AP-1 could be attenuated by ARI.</p><p><b>CONCLUSION</b>AR may participate in the pathological proliferation of MsC through the pathway related to the activation of AP-1.</p>