MicroRNA-98 regulates osteogenic differentiation of human bone mesenchymal stromal cells by targeting BMP2.

To study the effects of microRNA-98 (miR-98) on human bone mesenchymal stromal cells (hBMSCs). The patients undergoing hip arthroplasty were selected by inclusion/exclusion criteria for this study. The extracted hBMSCs were detected of osteogenic differentiation by alizarin red S staining, and of cell phenotype by flow cytometry. Bioinformatics, dual luciferase report, western blotting, RT-PCR and immunoblotting were used in our study. The hBMSCs were divided into miR-98 mimics, miR-98 negative control (NC), miR-98 inhibitors, Mock and miR-98 inhibitors + siBMP2 groups. Human bone mesenchymal stromal cells were extracted and purified in vitro and had specific cytological morphology, surface markers and abilities of self-renewal and differentiation. Compared with the NC group and Mock group, the miR-98 mimics group showed increased miR-98 level while the miR-98 inhibitors group decreased miR-98 level (both P < 0.01). Dual luciferase reporter showed BMP2 was the target gene of miR-98. The levels of mRNA and protein expression of BMP2, protein expression of RUNX2, alkaline phosphatase activity and osteocalcin content significantly decreased in the miR-98 mimics group while increased in the miR-98 inhibitors group and showed no changes in the NC group and Mock group (all P < 0.05). The miR-98 mimics group showed obviously declined stained red particles and the miR-98 inhibitors group showed opposite result. After lowering the expression of miR-98, osteogenic differentiation ability of hBMSCs rose, which was weakened by the transfection with siBMP2. miR-98 may regulate osteogenic differentiation of hBMSCs by targeting BMP2.

Correlation between polymorphism of endothelial nitric oxide synthase and avascular necrosis of femoral head.

OBJECTIVE: We analyzed the correlation between mutation in intron 4 and exon 7 of endothelial nitric oxide synthase (eNOS) and avascular necrosis of femoral head (ANFH). METHOD: A total of 260 ANFH cases without history of hip joint injuries were diagnosed and subject to staging according to Ficat standard, with 262 health subjects as control. Venous blood was collected to extract genome DNA, which was then amplified by PCR. The polymorphism of 27 bp repeat sequence in intron 4 and G894T polymorphism in exon 7 of eNOS gene was detected. RESULTS: The b/b, b/a and a/a genotype frequency of intron 4 was 77.7%, 19.2% and 3.1% in ANFH group, respectively, and that in the control group was 58.0%, 32.8% and 9.2%, respectively. The b allele frequency in ANFH group was obviously higher than that in the control (P<0.0001). The frequency of 894 G/G wild type, G/T heterozygote and T/T homozygote in eNOS exon 7 was analyzed by PCR-RLFP: 65.4%, 26.5% and 8.1% in ANFH group, and 46.2%, 37.8% and 16% in normal control, respectively. The frequency of TT genotype in ANFH was obviously higher than that in the control group (P<0.001). CONCLUSION: Polymorphism of eNOS was correlated with ANFH.

[Effect of mild moxibustion on macrophage number and collagen expression of raw surface tissue in chronic refractory skin ulcer rats].

OBJECTIVE: To observe the effect of mild moxibustion on the number of macrophages and contents of collagen I and III in the raw surface tissue in chronic skin ulcer rats so as to study its mechanism underlying promoting scar formation. METHODS: Eighty male SD rats were randomly divided into normal (n = 8), model (n = 24), TDP (n = 24) and moxibustion (n = 24) groups. Chronic refractory skin ulcer was established by making an open wound at the back and local intramuscular injection of hydrocortisone sodium succinate. For rats of the TDP and moxibustion groups, TDP irradiation or mild moxibustion was applied to the raw surface, bilateral "Shenshu" (BL 23) and "Zusanli" (ST 36) for 15 min, once daily for 7, 10 and 14 days, respectively. The number of macrophages in the raw surface tissue was counted under light microscope after H. E. staining and col- lagen I and III expressions of the raw surface tissue were detected by immunohistochemistry. RESULTS: In comparison with the normal group, the numbers of macrophages in the raw surface tissue were increased significantly in the model group on day 7, 10 and 14 (P < 0.05); while compared with the model group, the numbers of macrophages were increased further obviously in the moxibustion group on day 7 and 10 and in the TDP group on day 10 after the treatment (P < 0.05). Compared with the model group, the numbers of macrophages in both TDP and moxibustion groups were down-regulated obviously (P < 0. 05). In regard to collagen I and III expression of the raw surface tissue, compared with the normal group, the collagen I protein expression level was down-regulated markedly in the model group on the 7th day (P < 0.01); whereas in comparison with the model group, the expression levels of collagen I and III were increased considerably in the TDP and moxibustion groups on day 7 and 14 after the treatment (P < 0.05, P < 0.01). The ratios of collagen I/III expression were remarkably higher in the model group than in the normal group on day 7 and 14 (P < 0.05), and significantly lower in the TDP group on day 7 and 14 and in the moxibustion group on day 14 than in the model group (P < 0.05, P < 0.01). The effects of moxibustion were obviously superior to those of TDP in up-regulating macrophage number on day 10, up-regulating collagen I and III expressions on day 14, and down-regulating macrophage number on day 14 after the treatment (P < 0.05, P < 0.01). No significant differences were found between the TDP and moxibustion groups in up-regulating macrophage number, and collagen I and III protein expressions, and in down-regulating the ratios of collagen I/III expression on day 7 after the treatment (P > 0.05). CONCLUSION: Mild moxibustion can regulate the number of macrophages and strengthen the expression of collagen proteins in the raw surface tissue in the chronic skin ulcer rats, which may contribute to its effect in promoting wound healing and reducing scar formation.

[Effect of mild-warm moxibustion on microcirculation in the raw surface tissue of chronic refractory wound in skin ulcer rats].

OBJECTIVE: To observe the effects of mild-warm moxibustion on dynamic blood flow, microvessel count (MVC)and vascular endothelial growth factor (VEGF) expression in the wound tissue of the chronic skin ulcer in rats, so as to reveal its underlying mechanism in promoting wound recovery. METHODS: A total of 104 male SD rats with skin injury were randomly divided into control group (n=8), model group (n=32), TDP (far-infrared heating device) group (n=32) and moxibustion group (n=32). Chronic refractory raw surface wound model was established by muscular injection of Hydrocortisone Sodium Succinate. For rats of the TDP and moxibustion groups, TDP irridiation and mild-warm moxibustion were applied to the raw surface, bilateral "Shenshu" (BL 23) and "Zusanli" (ST 36) for 15 min, once daily for 3, 7 and 14 days respectively. The healing rate and the healing time of raw surface of the wound were observed. The blood flow of the raw surface of the wound tissue was measured by laser Doppler flowmeter and the MVC in granulation tissue of chronic skin ulcer was counted under light microscope. VEGF expression was detected by immunohistochemistry. RESULTS: In comparison with the control group, the healing rate of the wound raw surface was significantly lower and the healing time was prolonged in the model group (P < 0.01). Compared with the model group, the healing rates on day 3, 7, 10 and 14 were significantly higher and the healing time was strikingly faster in both TDP and moxibustion groups (P < 0.01, P < 0.05), and the effects of the moxibustion group in increasing the healing rate and shortening the healing time were significantly better than those of TDP group (P < 0.01). In comparison with the model group, the blood flow volume, MVC and VEGF expression levels on day 3 and 7 were upregulated significantly in both TDP and moxibustion groups (P < 0.01, P < 0.05); while the blood flow volume, MVC and VEGF expression level in the moxibustion group and the blood flow volume and VEGF expression level in the TDP group downregulated considerably on day 14 (P < 0.01). No significant difference was found between the TDP and moxibustion groups in the MVC on day 14 after the treatment (P > 0.05). CONCLUSION: Mild-warm moxibustion can promote wound healing, which is closely with its effects in increasing blood flow and MVC, and upregulating VEGF expression in the wound granulation tissue of the chronic skin ulcer.