Abstract
Background:
Although Semaphorin 3A (Sema3A)/ Neuropilin-1(NRP1)/Plexin A1 is one of the important targets in bone metabolism, few studies are done on this target in the glucocorticoids-induced osteoporosis. Luteolin is a chemical component of Honeysuckle and it has various bioactivities. The effect and study of Luteolin on the glucocorticoids-induced osteoporosis (primary osteoblasts model) remain unknown.
Objective:
The aim of this study was to investigate the action of Sema3A/ NRP1/Plexin A1 in Luteolin-induced osteoprotection against high-dose Dexamethasone.
Methods:
The effect of luteolin on the proliferation, late differentiation, and apoptosis of primary osteoblasts model of glucocorticoids-induced osteoporosis in vitro as well as the expression of Sema3A/NRP1/Plexin A1 are investigated by using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, Cell Counting Kit-8, reverse transcriptionquantitative real-time polymerase chain reaction, western bolting and so on.
Results:
Suckling SD rats' calvarial osteoblasts were isolated and identified. The glucocorticoids-induced primary osteoporosis cell model was established by 100 µM Dexamethasone in 48 h. (P<0.01) Luteolin promotes osteoblasts either in physiological condition (without Dexamethasone) or pathological condition (with Dexamethasone) at 1 µM concentration for 48h. (P<0.01). Luteolin partly reverses down-regulated expression of proliferation markers such as proliferating cell nuclear and CyclinD1. (P<0.01) Similarly, Luteolin partly reverses up-regulated expression of apoptosis markers such as Bax/B-cell lymphoma-2. (P<0.01) The expression of mRNA and protein of Sema3A/NRP1/Plexin A1 decreased in model one which significantly increased in Luteolin protecting one. (P<0.05) Interestingly, the late differentiation marker such as osteocalcin and collagenase sharply decreased in Luteolin protecting group compared with model one. (P<0.01).
Conclusion:
The thesis concludes that Luteolin promoted the proliferation of osteoblast and inhibited its apoptosis and late differentiation in this glucocorticoids-induced primary osteoporosis cell model. This function may be related to the expression of up-regulated Sema3A/NRP1/Plexin A1. Therefore, Luteolin may be a potential medicine for the glucocorticoids-induced osteoporosis.
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