BACKGROUND: Transformation growth factor β1 (TGF-β1) can promote bone marrow mesenchymal stem cells (BMSCs) migration and proliferation, but the underlying mechanisms remain unclear.OBJECTIVE: To observe the invasiveness of TGF-β1 on BMSCs cultured in vitro, and to investigate regulatory effect on Snail and matrix metalloproteinase 2 (MMP-2) expression.METHODS: Rat BMSCs were isolated and cultured with density gradient centrifugalization and adherence method. The influence of different concentrations of TGF-β1 on the BMSC migration was detected using the modified Transwell chambers. Small interfering RNA for Snail gene was synthesized and transfected into BMSCs by liposomel before TGF-β1 was treated, and the expression of Snail and MMP-2 before and after transfection were measured by western blot assay.RESULTS AND CONCLUSION: The exogenous TGF-β1 can induce a dose-dependent increase in cell migration, which peaked at 2 μg/L. The expression levels of Snail mRNA and MMP-2 mRNA were significantly increased after 2 μg/L TGF-β1 treatment. Snail gene can effectively inhibit the expression of MMP-2 promoted by TGF-β1. Experimental findings indicate that TGF-β1 could increase the MMP-2 expression and then promote the BMSCs migration through the upregulation of the Snail expression.

bThis study explored whether the transplantation of modified marrow stromal cells (MSCs) has angiogenic effects in a left middle cerebral artery occlusion infarction/reperfusion (MCAO I/R) rat model and preliminarily examined the mechanism of angiogenesis following cerebral infarction. MSCs were isolated by using a direct adherent method and cultured. Vascular endothelial growth factor (VEGF) was transfected into MSCs by employing the liposome transfection. The transfection efficiency was measured by the optical density method. The protein expression of VEGF gene before and after transfection was measured by Western blotting. SD rat model of transient occlusion of the left middle cerebral artery was established by using an approach of intra-luminal occlusion. Tetrazolium (TTC) and HE staining were performed to observe the cerebral infarction. ELISAs were used to measure the levels of VEGF in the rat cerebral tissues. The expression patterns of angiopoietin-2 (Ang-2) and CD34 in cells surrounding the area of infarction were immunohistochemistrically observed. Ang-2 protein expression in the tissue surrounding the area of infarction was measured by Western blotting. VEGF expression in the MSCs increased after transfection at a rate of approximately 28%±3.4%. ELISA showed that the expression of VEGF in the cerebral tissue was significantly increased after induction of infarction, peaking on the 4th day and decreasing to the levels of the sham surgery group (normal) within 7 to 10 days. The VEGF level was significantly higher at each time point in the VEGF-MSC and MSC groups compared to the model group. Moreover, the VEGF level was higher in the VEGF-MSC group than in the MSC group and stayed relatively high until the 10th day. The immunohistochemical results showed that 10 days after the infarction, the number of Ang-2 and CD34-expressing cells in the area surrounding the infarction was significantly higher in the VEGF-MSC group and the MSC group compared to the model group. Moreover, the VEGF level was higher in the VEGF-MSC group than the MSC group. A similar trend in Ang-2 protein expression was revealed by Western blotting. In the MCAO rat model transfected with modified MSCs over-expressing VEGF, compared to the MSC transplantation group, the concentration of VEGF was significantly increased in the brain tissue after cerebral infarction. In addition, the level of Ang-2 was up-regulated, with angiogenesis promoted, the blood supply to the areas surrounding the cerebral infarction increased, and neurological function improved. We are led to speculate that the synergistic effects of VEGF and Ang-2 may be responsible for the angiogenesis following cerebral infarction.

bThis study explored whether the transplantation of modified marrow stromal cells (MSCs) has angiogenic effects in a left middle cerebral artery occlusion infarction/reperfusion (MCAO I/R) rat model and preliminarily examined the mechanism of angiogenesis following cerebral infarction. MSCs were isolated by using a direct adherent method and cultured. Vascular endothelial growth factor (VEGF) was transfected into MSCs by employing the liposome transfection. The transfection efficiency was measured by the optical density method. The protein expression of VEGF gene before and after transfection was measured by Western blotting. SD rat model of transient occlusion of the left middle cerebral artery was established by using an approach of intra-luminal occlusion. Tetrazolium (TTC) and HE staining were performed to observe the cerebral infarction. ELISAs were used to measure the levels of VEGF in the rat cerebral tissues. The expression patterns of angiopoietin-2 (Ang-2) and CD34 in cells surrounding the area of infarction were immunohistochemistrically observed. Ang-2 protein expression in the tissue surrounding the area of infarction was measured by Western blotting. VEGF expression in the MSCs increased after transfection at a rate of approximately 28%±3.4%. ELISA showed that the expression of VEGF in the cerebral tissue was significantly increased after induction of infarction, peaking on the 4th day and decreasing to the levels of the sham surgery group (normal) within 7 to 10 days. The VEGF level was significantly higher at each time point in the VEGF-MSC and MSC groups compared to the model group. Moreover, the VEGF level was higher in the VEGF-MSC group than in the MSC group and stayed relatively high until the 10th day. The immunohistochemical results showed that 10 days after the infarction, the number of Ang-2 and CD34-expressing cells in the area surrounding the infarction was significantly higher in the VEGF-MSC group and the MSC group compared to the model group. Moreover, the VEGF level was higher in the VEGF-MSC group than the MSC group. A similar trend in Ang-2 protein expression was revealed by Western blotting. In the MCAO rat model transfected with modified MSCs over-expressing VEGF, compared to the MSC transplantation group, the concentration of VEGF was significantly increased in the brain tissue after cerebral infarction. In addition, the level of Ang-2 was up-regulated, with angiogenesis promoted, the blood supply to the areas surrounding the cerebral infarction increased, and neurological function improved. We are led to speculate that the synergistic effects of VEGF and Ang-2 may be responsible for the angiogenesis following cerebral infarction.
Angiopoietin-2 ; genetics ; metabolism ; Animals ; Bone Marrow ; metabolism ; pathology ; Cerebral Infarction ; genetics ; metabolism ; pathology ; Male ; Neovascularization, Pathologic ; genetics ; pathology ; Rats ; Rats, Sprague-Dawley ; Stromal Cells ; metabolism ; pathology ; Vascular Endothelial Growth Factor A ; genetics ; metabolism

Mitochondrial autophagy is a process to clear dysfunctional mitochondria in the cytoplasm to maintain the integrity of mitochondrial function and cell homeostasis. Mitochondrial autophagy is a complex physiological process， which can maintain the balance of mitochondrial quality and quantity， cell survival under starvation and harsh conditions， and the stability of the intracellular environment. Its molecular mechanism involves a variety of proteins. Many factors can induce mitochondrial autophagy， such as starvation， oxidative stress， hypoxia， depolarization， and other stresses. The accumulation of unfolded proteins can also induce mitochondrial autophagy. In recent years， as a research hotspot， the abnormality of mitochondrial morphology and function is closely related to the occurrence of a variety of diseases. The research on mitochondrial autophagy and the pathogenesis of clinical diseases has attracted more attention， such as tumors， cardiovascular diseases， liver diseases， nervous system diseases， and glucose metabolism disorders. It has been found that regulating mitochondrial autophagy may inspire the treatment of some diseases. Meanwhile， clinical researchers have paid more attention to traditional Chinese medicine （TCM）. As revealed by in-depth research， Chinese medicine has a certain value in regulating mitochondrial autophagy. The research on the pathogenesis of mitochondrial autophagy in related diseases and the intervention of Chinese medicine has found that there are many reports on the regulation of mitochondrial autophagy by Chinese medicine in tumors， cardiovascular diseases， and nervous system diseases. However， the mechanism of mitochondrial autophagy， the balance of mitochondrial autophagy， and the difference in the activation or inhibition of mitochondrial autophagy by Chinese medicine remain unclear. The regulation of mitochondrial autophagy has become a new research target strategy of Chinese medicine in the prevention and treatment of diseases. This paper reviewed the available literature in recent years to provide reference materials for the regulation of mitochondrial autophagy by Chinese medicine and ideas for the follow-up research of Chinese medicine in mitochondrial autophagy.