Baicalin promotes apoptosis and inhibits proliferation and migration of hypoxia-induced pulmonary artery smooth muscle cells by up-regulating A2a receptor via the SDF-1/CXCR4 signaling pathway.

BACKGROUND: Baicalin is a flavonoid compound that exerts specific pharmacological effect in attenuating the proliferation, migration, and apoptotic resistance of hypoxia-induced pulmonary artery smooth muscle cells (PASMCs). However, the underlying mechanism has not been fully elucidated yet. Although our previous studies had indicated that activation of A2aR attenuates CXCR expression, little is known about the relationship between A2aR and SDF-1/CXCR4 axis in hypoxic PASMCs. In this study, we aimed to investigate the effect of A2aR on the SDF-1/CXCR4 axis in hypoxic PASMCs, the mechanism underlying this effect, and whether baicalin exerts its protective functions though A2aR. METHODS: Rat PASMCs were cultured under normoxia/hypoxia and divided into nine groups: normoxia, hypoxia, hypoxia + AMD3100 (a CXCR4 antagonist), hypoxia + baicalin, hypoxia + negative virus, normoxia + A2aR knockdown, hypoxia + A2aR knockdown, hypoxia + CGS21680 (an A2aR agonist), and hypoxia + A2aR knockdown + baicalin. Lentiviral transfection methods were used to establish the A2aR knockdown model in PASMCs. Cells were incubated under hypoxic conditions for 24 h. Expression levels of A2aR, SDF-1, and CXCR4 were detected using RT-qPCR and western blot. The proliferation and migration rate were observed via CCK-8 and Transwell methods. Cell cycle distribution and cell apoptosis were measured by flow cytometry (FCM) and the In-Situ Cell Death Detection kit (Fluorescein). RESULTS: Under hypoxic conditions, levels of A2aR, SDF-1, and CXCR4 were significantly increased compared to those under normoxia. The trend of SDF-1 and CXCR4 being inhibited when A2aR is up-regulated was more obvious in the baicalin intervention group. Baicalin directly enhanced A2aR expression, and A2aR knockdown weakened the function of baicalin. SDF-1 and CXCR4 expression levels were increased in the hypoxia + A2aR knockdown group, as were the proliferation and migration rates of PASMCs, while the apoptotic rate was decreased. Baicalin and CGS21680 showed opposite effects. CONCLUSIONS: Our data indicate that baicalin efficiently attenuates hypoxia-induced PASMC proliferation, migration, and apoptotic resistance, as well as SDF-1 secretion, by up-regulating A2aR and down-regulating the SDF-1/CXCR4 axis.

Electro-Acupuncture Promotes Endogenous Multipotential Mesenchymal Stem Cell Mobilization into the Peripheral Blood.

BACKGROUND/AIMS: Mobilization of endogenous stem cells is an appealing strategy for cell therapy However, there is little evidence for reproducible, effective methods of mesenchymal stem cell (MSC) mobilization. In the present study, we investigated the mobilizing effect of electro-acupuncture (EA) on endogenous MSCs. METHODS: Normal adult rats were randomly divided into six groups, namely, EA for 14 days (EA14d), sham EA14d, EA21d, sham EA21d and matched control groups. MSC mobilization efficiency was determined by colony-forming unit fibroblast (CFU-F) assays. Mobilized peripheral blood (PB)-derived MSCs were identified by immunophenotype and multi-lineage differentiation potential. RESULTS: CFU-F frequency was significantly increased in the PB of EA14d rats compared with the sham EA and control groups. Moreover, the number of CFU-Fs was increased further in the EA21d group. MSCs derived from EA-mobilized PB were positive for CD90 and CD44, but negative for CD45. Additionally, these cells could differentiate into adipocytes, osteoblasts, chondrocytes and neural-like cells in vitro. Finally, stromal cell-derived factor-1α (SDF-1α) was increased in the PB of rats subjected to EA, and the migration of MSCs was improved in response to SDF-1α. CONCLUSIONS: MSCs with multi-lineage differentiation potential can be mobilized by EA. Our data provide a promising strategy for MSC mobilization.

[Buyang Huanwu decoction promotes neuroblast migration from subventricular zone via inducing angiogenesis after ischemia].

OBJECTIVE: To study the effect of Buyang Huanwu decoction (BYHWD) inducing angiogenesis on the neuroblast migration from the subventricular zone and its mechanisms after focal cerebral ischemia. METHOD: The middle cerebral artery occlusion (MCAO) was performed to mice for 30 minutes to establish the model. The rats were divided into sham group, model group, BYHWD group and endostatin group. BYHWD (20 g x kg(-1), ig) and endostatin (10 µg, sc) were administered 24 h after ischemia once a day for consecutively 14 days. At 14 d after ischemia, the density of micro-vessel and the number of neuroblasts in the ischemia border zone were determined by immunofluorescence staining. The mRNA and protein expression of cell-derived factor-1 (SDF-1) and brain-derived neurotrophic (BDNF) were examined by real-time PCR and Western blot. RESULT: Compared with the model group, BYHWD significantly increased the density of micro-vessel and the number of DCX positive cells in the ischemia border zone (P < 0.01), and significantly increased the SDF-1 and BDNF mRNA and protein expression (P < 0.01). Compared with BYHWD group, endostatin significantly reduced the density of micro-vessel and the number of DCX positive cells in the ischemia border zone (P < 0.01), as well as the SDF-1, BDNF mRNA and protein expression (P < 0.01). CONCLUSION: BYHWD could promote the neuroblast migration from the subventricular zone via inducing angiogenesis after cerebral ischemia, the mechanism may be correlated with up-regulating the expression of SDF-1 and BDNF.

Region-specific plasticity in the epileptic rat brain: a hippocampal and extrahippocampal analysis.

PURPOSE: Recent evidence suggests that aberrant neuro/gliogenesis and/or inflammation play critical roles in epileptogenesis. Although the plastic and inflammatory changes have been described in the postseizure hippocampus, little data is available concerning extrahippocampal regions, notably in the piriform and entorhinal cortices, amygdala, and parts of the thalamus. In this study, we examined histological changes in whole epileptic rat brain, with respect to cell death, cell genesis, and inflammation. METHODS AND RESULTS: Experimental status epilepticus (SE) was induced using a lithium-pilocarpine injection. Neuronal death was evident in the amygdala, piriform, and entorhinal cortices, as well as the subfields of hippocampus. Microglial activation was observed in more extended limbic areas, such as, the hippocampus, entorhinal, perirhinal and piriform cortices, amygdala, thalamus, and hypothalamus, and a robust increase of cell genesis was noted in these damaged areas. The majority of newly generated cells in extrahippocampal areas proliferated in situ, and differentiated mainly into astrocytes or oligodendrocytes. In addition, stromal cell-derived factor-1alpha was found to be induced in close temporal and anatomical association with seizure-induced plasticity. DISCUSSION: These findings indicate that neuronal death, inflammation, and cell genesis are substantially associated throughout the entire brain and that they may influence the epileptogenic process and clinical manifestations.