The Mechanism Of Astragalus Polysaccharide In Improved-osteoporosis In Rats Based On Omics

Osteoporosis is a systemic disease characterized by bone loss,bone tissue microstructure destruction,increased bone fragility,and easy fracture.With the development of the society and economy,the aging trend of China's population has become increasingly severe.The increase in bone fragility has led to an increase in the incidence of osteoporosis and its fractures,and this has brought a huge economic and social health burden.Therefore,the health management of patients with osteoporosis is very important to preventing osteoporosis and delaying the occurrence of fractures.Due to the side effects caused by drug intervention,natural active substances without side effects are favored.Astragalus polysaccharide(APS)is the most important natural active ingredient in Astragalus.It is a non-starch polysaccharide.Studies have reported that it has the effect of anti-osteoporosis,but there is no report on how to send a signal from the intestine and then produce an anti-osteoporosis effect on the body.In this study,a glucocorticoid method was used to construct osteoporosis rat model;the differences were compared in the cecuim flora of different groups of rats treated with APS;the key bacteria affected by APS were analyzed;the transcriptome and methylome were applied to analyze the effect of polysaccharides on the genome and protein expression of colonic epithelial tissue.Then,the mechanism of polysaccharides improving osteoporosis was further discovered in this manuscript.Our results showed:1)APS significantly increased the bone density of OP(osteoporosis)rats'femur(p<0.05).The slice observation showed that astragalus polysaccharide significantly improved the bone microstructure,increased the trabecular bone area,circumference,thickness,and quantity,reduced the separation of trabecular bone(p<0.05),and significantly reduced the content of anti-tartrate acid phosphatase ACP5,a marker of osteoclast differentiation in serum(p<0.05),and significantly reduced serum tumor necrosis factor(TNF-?)and interleukin-2(IL-2)content(p<0.05).2)APS intervention changed the structure of the intestinal flora of OP rats.A total of 31genera significantly changed in all groups.The intervention of APS significantly increased c?Bacteroidia,p?Bacteroidetes,o?Bacteroidales,f?Prevotellaceae,o?Corynebacteriales,g?Corynebacterium?1,f?Corynebacteriaceae,c?Actinobacteria,o?Bacillales,f?Staphylococcaceae,g?Prevotellaceae?UCG?003,g?Staphylococcus and g?Allpprevotella;and Astragalus polysaccharide intervention restored the uncultured?bacterium?f?Ruminococcaceae,Alloprevotella,Ruminococcaceae?UCG-014,Blautia and Lactobacillus that changed by model group,and had a dose-dependent relationship.The results showed that these 5 genera of bacteria are potentially key bacteria for Astragalus polysaccharide to affect OP rats.3)The methylation level of colon epithelial tissue genes in OP rats and OP rats that treated with APS changed;compared with normal rats,the methylation level of osteoporotic rats is reduced,while APS treatment increased the methylation level.Further studies show that APS increased the content of methyl donor S-adenosylmethionine,betaine,VB₁₂,and folic acid in the contents of the cecum(p<0.05).4)APS intervention reduced the expression of Fosb in the colon epithelial tissue of OP rats and decreased the production of AP-1 protein in the osteoclast differentiation pathway of OP rats;APS increases the production of RYR,GPCR,BCR and other proteins in the calcium signaling pathway in the colonic epithelial tissue of OP rats.In conclusion,APS changed the structure of the intestinal flora of OP rats.Uncultured?bacterium?f?Ruminococcaceae,Alloprevotella,Ruminococcaceae?UCG-014,Blautia and Lactobacillus were inferred as the five potentially key bacteria.These bacteria might increase the methylation level of colonic epithelium in OP rats and changed the expression level of colonic epithelial genes,thereby increasing the expression of some proteins in the osteoclast differentiation pathway and calcium pathway in the colonic epithelial tissue of OP rats,and promoting the release of intestinal calcium,inhibiting osteoclast differentiation.It can be seen that APS has anti-OP effect through anti-inflammatory,reducing osteoclast differentiation and other ways.