Effects of glucocorticoid and bisphosphonates on Hedgehog signaling pathway in human bone mesenchymal stem cells and bone tissue / 中华风湿病学杂志

ABSTRACT

Objective To investigate the effect of glucocorticoid and bisphosphonate on Hedgehog signaling pathway in human bone mesenchymal stem cells (hBMSCs) and bone tissue.Methods ① Bone biopsy testforty cases of systemic lupus erythematosus (SLE) patients were divided into 2 groups20 cases in newly diagnosis group,20 cases in the GCs group (the dosage of glucocorticoids was higher than 1 mg·kg-1·d-1).Patients in the GCs group was randomly divided into 2 groups10 cases in the control group were without anti-osteoporosis treatment,10 cases in treatment group received alendronate 70 mg once a week.All of the patients had bone marrow puncture after24 weeks,and the value of average optical density of Gli1 was tested with immunohistochemistry.② Cell culturehBMSCs cultured in normal medium were intervened with rh-SHHN and methylprednisolone (10-3 mol/L,10-5 mol/L) after successfully identified.Quantitative polymerase chain reaction (PCR) was used to detectthe mRNA expression of Gli1.The final calcium nodules was detected by Alizarin red staining.hBMSCs cultured in osteogenesis medium were intervened with bisphosphonate and methylprednisolone (10-3 mol/L) after successfully identified.Quantitative PCR was used to detect the expression of Gli1 mRNA.Alizarin red staining was used to detect the final calcium nodules.Comparisons between the two groups were carried out using t-test while the difference analysis of multi-groups were tested by factorial analysis.Results The average optical density of Gli1 in the GCs group (47±7) was less than the newly diagnosed group (61±12) (t=4.442,P＜0.01),and it was less in the control group (51±6) than in the treatment group (42±6) (t=3.701,P=0.002).When normally cultured,high and moderate concentration of methylprednisolone suppressed the mRNA (0.38±0.04; 0.68±0.24) (F=8.748,P＜0.01) expression of Gli1 which was initially stimulated by rh-SHHN (2.01 ±0.38).And the final calcium nodules in groups which contained methylprednisolone were much less than rh-SHHN only group.When hBMSCs were cultured in osteogenesis medium,compared with the methylprednisolone group (0.024±0.011),the expression of Gli1mRNA(0.034-0.006) (t=7.62,P＜0.01) and the final calcium nodules were significantly improved by bisphosphonate.Conclusion High and moderate doses of glucocorticoids inhibit hBMSC osteogenesis by inhibiting Gli1.Low concentration of alendronate can not only stimulate hBMSC osteogenesis differentiation but also can remit the inhibition effects of GCs through the way of Hedgehog.