Apigenin accelerates lipopolysaccharide induced apoptosis in mesenchymal stem cells through suppressing vitamin D receptor expression / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Transplantation of mensenchymal stem cells (MSCs) has been proposed as a promising way for tissue engineering. However, the application of MSCs for transplantation will undergo apoptosis due to the extremely harsh microenvironment such as excessive inflammation. Apigenin (API) has been reported to protect cells against inflammatory damage and cell death by exhibiting anti-inflammatory and anti-oxidative capacity. Here we investigated the modulatory effects of API in lipopolysaccharide (LPS)-mediated inflammation and apoptosis of MSCs, and further defined the underlying mechanism.</p><p><b>METHODS</b>Effects of different concentrations of API (0, 5, 10, 20, 40 and 80 µmol/L) for 24 hours, and LPS (0, 0.5 and 5.0 µg/ml) for 6 hours and 24 hours on MSCs viability were assayed by MTT. Based on this, MSCs were pretreated with different concentrations of API (0 - 40 µmol/L) at the indicated times (6, 12 and 24 hours) followed by exposure to 5 µg/ml LPS for 24 hours. MTT, phase-contrast microscopy, annexinV/propidium iodide (PI) double stain flow cytometry (FCM) and Hoechst staining were applied to explore the effects of API on MSCs induced by 5 µg/ml LPS for 24 hours. In addition, reverse-transcription polymerase chain reaction (RT-PCR) was applied to detect the mRNA expression of pro-inflammatory factors including cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), nuclear factor-kappa B (NF-κB), pro-apoptotic gene caspase-3, Bad, and anti-apoptotic gene Bcl-2. Moreover, AutoDock software was used to imitate the docking score of API and vitamin D receptor (VDR). In parallel, Western blotting and RT-PCR were used to investigate protein and mRNA expression of VDR.</p><p><b>RESULTS</b>MSCs stimulated with LPS 5 µg/ml for 24 hours was used as a model of apoptosis induced by over inflammatory stimulus. API (0 - 40 µmol/L) had non-toxic effect on MSCs; however, it could decrease mRNA expression of COX-2, iNOS and NF-κB at different time points in MSCs induced by LPS, except for API at the concentration of 5 µmol/L.</p><p><b>RESULTS</b>from phase-contrast microscopy, MTT, Hoechst staining and AnnexinV/PI double stain FCM demonstrated that with the increasing concentrations of API and extension of administrating time, significant morphological changes of MSCs occurred, viability of cells was strongly inhibited, and meanwhile, apoptosis of LPS-administrated MSCs was exacerbated, compared with LPS individual group. In addition, API promoted caspase-3, Bad mRNA expression and inhibited Bcl-2 mRNA expression in a time-dependent and concentration- dependent manner. Further study found that pro-apoptosis effect of API was related to suppress VDR expression.</p><p><b>CONCLUSIONS</b>API could inhibit the expression of inducible inflammatory factors, therefore exert the strong anti-inflammatory function. However, API could not protect MSC apoptosis induced by LPS but amplified the apoptosis. The apoptosis is related to Bad/Bcl-2 increasing and caspase-3 activation, which is mediated through suppressing VDR expression.</p>

Inhibition of Testudinis Carapax et Plastrum extracts targeting BMP4 pathway on PC12 cell apoptosis / 中草药

Objective: To observe the protection of Testudinis Carapax et Plastrum extracts (TCPE) on serum starvation-induced PC12 cell apoptosis and explore its mechanism. Methods: The PC12 apoptosis model was established by serum starvation for 3 d. The cells were randomly divided into four groups: control group, model group, low-dose and high-dose (3 and 30 μg/mL) TCPE groups. In the three days of the treatment, cell absorbance was determined by MTT, ratio of cell apoptosis was examined by Annexin V/PI double stain flow cytometry (FCM), Caspase-3, BMP4, BMPR-IA, and p-Smad1/5/8 signaling molecular expression were detected by Western blotting, and the anti-apoptotic effect of TCPE was observed after blocking BMPs signal pathway. Semi-quantitative analysis of bands was carried out by Bio-Rad Quantity One gel analysis system. Results: MTT and FCM analyses demonstrated that TCPE could increase PC12 cell viability and decrease their apoptotic ratios in a dose dependent manner. Western blotting results showed that TCPE could decrease Caspase-3 expression, promote the expression of BMP4, BMPR-IA, and p-Smad1/5/8. There was statistically significant difference between TCPE (3 and 30 μg/mL) groups and model group (P<0.05, P<0.01) in all above results. While TCPE had no effect on the expression of BMP2, BMP7, and BMPR-II. BMPR-IB hadn't been detected. The anti-apoptotic activity was partially mitigated by neutralizing BMP4 antibody. Conclusion: TCPE has the capacity to inhibit the apoptosis of PC12 induced by serum starvation in a dose dependent manner and its mechanism may be associated with partially activating and up-regulating the expression of BMP4 signaling pathway.

Effect of Basic Fibroblast Growth Factor on Apoptosis of Scleral Cells in Lens-induced Myopia of Guinea Pig / 环境与健康杂志

Objective To investigate the effect of basic fibroblast growth factor(bFGF)on the apoptosis of scleral cells in the posterior pole in lens-induced myopia of guinea pigs and to discuss the mechanism of bFGF in inhibiting the formation of myopia. Methods Four-week-old cleaning healthy guinea pigs were randomly divided into the control group,LIM group,LIM+PBS group, LIM+the bFGF 100 ng group,LIM+the bFGF 500 ng group,LIM+the bFGF 1 000 ng group,15 in each.Except the control group, the right eye of guinea pig in other groups wore-10 D concave lens for 7 days and then different concentration of bFGF or PBS were injected into the vitreous cavity,3 days later injected again.After 15 days of-10 D concave lens treatment,the eyeballs were removed and the apoptotic cells in the scleras were determined by electron microscopy,TUNEL technique and flow cytometry.The proliferation of scleral cells in the posterior pole were determined by Ki-67 immune histochemistry stain.Results Compared with the control group,the significant differences were detected in the right eyes of LIM group(P