Department of Traditional Chinese Medicine, Beijing JiShuitan Hospital, Beijing, China.
Graduate School, Beijing University of Chinese Medicine, Beijing, China.
Immunol Invest. 2022 Apr;51(3):465-479. doi: 10.1080/08820139.2020.1837864. Epub 2020 Nov 3.
Osteoporosis is a common metabolic bone disease with high prevalence. Tetrandrine (TET) suppressed osteoclastogenesis, while the roles of TET in osteoporosis regulation remained unclear. Thus, the study aimed to investigate the effect of TET on osteoporosis and the underlying mechanism.
The osteoporosis rabbit model was established through anterior cruciate ligament transection (ACLT) and bilateral ovariectomy (OVX). The degeneration of articular cartilage was assessed using HE staining and Alcian blue staining. The liver and kidney tissue injury was determined using HE staining. The activity of osteoclasts was evaluated using Tartrate-resistant acid phosphatase (TRAP) staining. The changes in bone structural parameters were determined through measuring the BMD, BV/TV, Tb.Th, Tb.N, and Tb.Sp, and the serum levels of calcium and phosphorus. Macrophage polarization was determined using Flow cytometry.
The bone structural parameters including BMD, BV/TV, Tb.N, Tb.Th and Tb.Sp were changed in osteoporosis rabbit, which was reversed by TET. Besides, TET suppressed the increased serum levels of calcium and phosphorus in osteoporosis rabbit. Furthermore, TET inhibited the degeneration of articular cartilage and the activity of osteoclasts induced by osteoporosis. Moreover, TET inhibited the levels of MMP-9, PPAR-γ, RANKL, β-CTX and TRACP-5b, and increased the levels of OPG, ALP and osteocalcin (OC) in osteoporosis. Additionally, TET promoted macrophage transformation from M1 to M2 in osteoporotic and inhibited the production of IL-1β, TNF-α, and IL-6. TET also inhibited the p65 phosphorylation in osteoporosis. Besides, TET reversed RANKL-induced osteoclasts proliferation, p65 phosphorylation, and the expression changes of RANKL, Ki67, PPAR-γ, ALP, OPG.
TET attenuated bone structural parameters including BMD, BV/TV, Tb.N, Tb.Th and Tb.Sp, inhibited articular cartilage degeneration, promoted bone formation, inhibited the inflammatory response, and promoted macrophage transformation from M1 to M2 via NF-κB inactivation in osteoporosis. TET may be a promising drug for osteoporosis therapy.
TET: Tetrandrine; ACLT: anterior cruciate ligament transection; OVX: ovariectomy; TRAP: Tartrate-resistant acid phosphatase; BMD: bone mineral density; BV/TV: Bone volume/total volume; Tb.Th: trabecular thickness; Tb.N: trabecular number; Tb.Sp: trabecular separation; MMP-9: Matrix metallopeptidase 9; PPAR-γ: Peroxisome proliferator-activated receptor gamma; RANKL: Receptor activator of nuclear factor kappa-B ligand; OPG: Osteoprotegerin; ALP: alkaline phosphatase; OC: osteocalcin; β-CTX: β isomer of C-terminal telopeptide of type I collagen; TRACP-5b: Tartrate-resistant acid phosphatase 5b; TNF-α: tumor necrosis factor-α; IL-1β: interleukin-1β; IL-6: interleukin 6; NF-κB: Nuclear factor kappa B; PKC-α: Protein kinase C alpha; qRT-PCR: Quantitative real-time polymerase chain reaction.
骨质疏松症是一种常见的代谢性骨病，患病率较高。汉防己甲素（TET）抑制破骨细胞生成，但其在骨质疏松症调节中的作用尚不清楚。因此，本研究旨在探讨 TET 对骨质疏松症的作用及其潜在机制。
通过前交叉韧带切断（ACLT）和双侧卵巢切除术（OVX）建立骨质疏松症兔模型。通过 HE 染色和阿尔辛蓝染色评估关节软骨退变。通过 HE 染色确定肝肾功能损伤。通过抗酒石酸酸性磷酸酶（TRAP）染色评估破骨细胞活性。通过测量骨密度（BMD）、骨体积/总体积（BV/TV）、骨小梁厚度（Tb.Th）、骨小梁数量（Tb.N）和骨小梁间距（Tb.Sp）以及血清钙和磷水平来评估骨结构参数的变化。使用流式细胞术确定巨噬细胞极化。
骨质疏松症兔的骨结构参数（包括 BMD、BV/TV、Tb.N、Tb.Th 和 Tb.Sp）发生改变，TET 可逆转这种改变。此外，TET 抑制了骨质疏松症兔血清中钙和磷水平的升高。此外，TET 抑制了骨质疏松症引起的软骨退变和破骨细胞活性。此外，TET 抑制了 MMP-9、PPAR-γ、RANKL、β-CTX 和 TRACP-5b 的水平，增加了 OPG、ALP 和骨钙素（OC）的水平。此外，TET 促进了破骨细胞向 M2 型转化，抑制了 IL-1β、TNF-α 和 IL-6 的产生。TET 还抑制了骨质疏松症中的 p65 磷酸化。此外，TET 逆转了 RANKL 诱导的破骨细胞增殖、p65 磷酸化以及 RANKL、Ki67、PPAR-γ、ALP、OPG 的表达变化。
TET 通过 NF-κB 失活减轻了包括 BMD、BV/TV、Tb.N、Tb.Th 和 Tb.Sp 在内的骨结构参数，抑制了软骨退变，促进了骨形成，抑制了炎症反应，并促进了巨噬细胞从 M1 向 M2 转化，在骨质疏松症中具有潜在的治疗作用。
