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As a kind of pluripotent stem cells, bone marrow mesenchymal stem cells mainly differentiate into osteoblasts and adipocytes in the bone marrow microenvironment. This mutual restriction and interaction are summarized as bone-fat balance. This dynamic balance plays a crucial role in the maintenance of bone homeostasis. In the process of bone-fat interaction, bone marrow adipose tissue is an important carrier and key pathway for communicating the signals, and mediates various metabolic regulatory processes in the bone marrow microenvironment. In recent years, with the in-depth study of bone-fat metabolism, the related regulatory network of osteoporosis prevention and treatment has been gradually revealed. However, there is still a lack of systematic explanation for the differentiation state and molecular mechanism of bone-fat under physiological and pathological conditions. Therefore, this study intends to analyze the molecular mechanism of bone-fat balance in the perspective of bone marrow microenvironment by summarizing relevant literature and combining our research, in order to provide new ideas for the prevention and treatment of osteoporosis. [ABSTRACT FROM AUTHOR]

No study has systematically reviewed the application of Guilu Erxian glue ( GEG) in the treatment of osteoporosis. The current study collected and analyzed studies related to clinical applications and fundamental experiments regarding GEG. Clinical trials found that GEG could promote bone formation, inhibit bone resorption, and improve bone metabolism outcomes. The potential mechanism is related to the regulation of TGF-β and NF-KB signaling pathways. However, several limitations were discovered, including a lack of study quantity, various clinical use patterns, and debates on the cell-level interventions. Those limitations hinder further applications of GEG in the management of osteoporosis and are requested to be resolved with future study. [ABSTRACT FROM AUTHOR]

Objective To observe the effects of osthol-loaded N-octyl-O-sulfonyl chitosan micelles ( NSC-OST) on bone microstructures and bone resorption in ovariectomized osteoporotic rats, and to explore its molecular mechanism of anti-osteoporosis. Methods Forty female SD rats were randomly divided into 5 groups： sham group (Sham) , model group (Ovx) , nilestriol group (Nil) , osthol ( OST) , osthol/chitosan derivative micelle group (NSC-OST). Except for sham operation group, osteoporosis models were established by removing bilateral ovaries. After 12 weeks of continuous administration, osteoporosis models were established. The effects of drugs on bone microstructures was observed with HE staining and micro-CT detection on two-dimensional and three-dimensional morphological perspectives, respectively. The effects of drugs on osteoclast formation and differentiation were observed with tartrate resistant acid phosphatase (TRAP) staining. The effects of drugs on specific molecules NFATcl, c-fos and CTSK expression were detected using immunohistochemistry. Results HE staining result showed that the osteoporosis-like changes induced by modeling in the drug groups improved significantly, and the effect in Nil group was the most obvious, followed by NSC-OST group and OST group. Micro-CT analysis showed that NSC-OST significantly improved BMD and BV/TV of the femur in rats (P< 0. 05) , and significantly improved Tb. The three indexes Tb.N, Tb.Sp, and Tb.Th (P<0. 05) were better than those in OST group, but slightly worse than those in NIL group. TRAP staining showed that NSC-OST significantly inhibited the osteoclast formation parameters N.Oc/BS and Oc.S/BS (F<0. 05) , and the effect was better than that in OST group, but slightly worse than that in NIL group. Immunohistochemical result showed that NSC-OST inhibited the expression of osteoclast-specific molecules NFATcl , c-fos, and CTSK. The inhibitive effect on the first two indicators was similar in NSC-OST group and in Nil group. When CTSK was inhibited, the efficacy in NSC-OST group was less than that in Nil group but more than that in OST group. Conclusion NSC-OST significantly improves the bone microstructures in ovariectomized rats, and its anti-osteoporosis effect may be related to the inhibition of osteoclast formation and differentiation. [ABSTRACT FROM AUTHOR]

Objective To investigate the influence of osthole (OST) on RAW264.7 cell lines of mouse monocytes differentiating to osteoclasts and study the related mechanism. Methods Osteoclasts were induced and cultured in vitro by using RAW264.7 cell lines, and then RAW264.7 cell line was divided into negative group, control group and OST group. RAW264.7 cell lines were induced to differentiation by using RANKL, and OST group was intervened with high-dose, mid-dose and low-dose OST (100 μmol/L, 10μmol/L, 1 μmol/L, high-dose, mid-dose and low-dose OST groups) for corresponding time. CCK-8 method was used to screen non-cytotoxic medicinal concentration group, and anti-tartaric acid phosphatase (TRAP) staining method was used to determine number of TRAP positive cells and fusion index. The influence of OST on bone absorptive function was reviewed through detecting area of dissolving pit and fluorescence intensity in bone absorption board. The influence of OST on expressions of nuclear factor of activated T cell (NFAT) and nuclear factor-κB (NF-κB) in RAW264.7 cell lines were observed by using luciferase reporter gene method. The influence of OST on expressions of nuclear factor of activated T cell-1 (NFATc1), CTSK, MMP-9, TRAP, INTE-BETAβ3 and c-Src was detected by using q-PCR. The influence of OST on expressions of p65, IκB, p-IκB and p65 in NF-κB signaling pathway was detected by using Western blotting assay. Results There were 2 medicinal concentration groups (1 μmol/L and 10 μmol/L, low-dose group and mid-dose group) screened by using CCK-8 method. TRAP positive cells and fusion index were significantly lower in all OST groups than those in control group (P<0.05), which was more significant in mid-dose OST group (P<0.05). The related area of bone absorption and fluorescence intensity were significantly inhibited in OST group (P<0.05), which was more significant in mid-dose OST group (P<0.05). OST inhibited significantly the initiations of NFAT and NF-κB (P<0.05) and expressions of osteoclast related genes including NFATc1, and except of Integrin-BETA3 and c-Src, other related genes had statistical difference between low-dose group and mid-dose group (P<0.05). Compared with control group, the protein expression of p-IκB was inhibited significantly (P<0.05), expressions of IκB and p65 were improved (P<0.05), and protein expression of p65 was inhibited (P<0.05) in all OST groups. Conclusion OST can induce down-regulations of NFATc1 and related transcription factors to control differentiation of osteoclasts through inhibiting expression of NF-κB signaling pathway. [ABSTRACT FROM AUTHOR]