紫草素对激素诱导骨质疏松大鼠骨代谢的治疗机制研究

目的探讨紫草素( SKN)对骨质疏松大鼠骨代谢的治疗机制。方法 2022年 1―6月通过糖皮质激素诱导大鼠骨质疏松症，采取腹腔注射紫草素对大鼠进行治疗，通过腹腔注射 shRNA-前蛋白转化酶枯草溶菌素( PCSK5)敲低大鼠体内 PCSK5水平。骨密度仪测量大鼠股骨骨密度( BMD)酶联免疫吸附测定( ELISA)大鼠血清骨钙素( BGP)及 Ⅰ型胶原羧基末端肽(CTX)，实时荧光定量 PCR(qRT-PCR)检测大鼠股骨，组织 PCSK5信使 RNA(mRNA)水平，免疫共沉淀验证 PCSK5与生长分化因子 11(GDF11)蛋白相互作用，蛋白质印迹法检测大鼠股骨组织 GDF11蛋白水平。结果与磷酸缓冲盐溶液( PBS)组( 0.23±0.01)g/ cm2比较，糖皮质激素使得糖皮质激素性骨质疏松症( GIOP)(0.12±0.01)g/cm2 BMD值降低( P<0.05)，GIOP+二甲亚砜( DMSO)组( 0.11±0.01)g/cm2较 GIOP+SKN组( 0.18±0.01)g/cm2相比BM组D值降低( P<0.05)； PBS组 PCSK5 mRNA表达水平量显著低于 GIOP组( 1.01±0.01比 0.23±0.02，P<0.05)GIOP+DMSO显著低于 GIOP+SKN组( 0.24±0.01比 0.81±0.16，P<0.05)，GIOP+DMSO+ si-NC组显著高于 GIOP+DMSO+si-PCSK5组，(0.82±0.06比 0.38±0.03，P<0.05)； PBS组 GDF11表达量显著低于 GIOP组( 0.30±0.01比 1.22±0.11，P<0.05)，GIOP+DMSO组显著高于 GIOP+SKN组(1.28±0.11比 0.52±0.04，P<0.05)GIOP+DMSO+si-NC组显著低于 GIOP+DMSO+si-PCSK5组( 0.49±0.04比 0.87±0.16，P<0.05)。结论紫草素调控 PCSK5/GDF11路促进骨质疏松大鼠骨通，代谢。

Therapeutic mechanism of shikonin on bone metabolism in hormone-induced osteoporosis rats

Objective To investigate the therapeutic mechanism of shikonin on bone metabolism in osteoporotic rats.Methods The osteoporosis of rats was induced by glucocorticoid from January to June 2022, and the rats were treated by intraperitoneal injection ofshikonin.The level of PCSK5 in rats was knocked down by intraperitoneal injection of shRNA-PCSK5. Bone mineral density was mea-sured by bone densitometer. Serum osteocalcin (BGP) and type I collagen carboxyl terminal peptide (CTX) were detected by ELISA kit.The level of PCSK5 mRNA in rat femur was detected by qRT-PCR. The interaction of PCSK5 and GDF11 protein was verified by co-im- munoprecipitation. The level of GDF11 protein in rat femur was detected by western blotting. Results Compared with PBS group(0.23±0.01)g/cm2,glucocorticoids significantly decreased BMD value in GIOP group (0.12±0.01)g/cm2 (P<0.05). BMD value of GIOP+ DMSO (0.11±0.01)g/cm2 was lower than that of GIOP+SKN group (0.18±0.01)g/cm2(P<0.05).The Relative expression ofPCSK5 mRNAexpression level in PBS group was significantly lower than that in GIOP group (1.01±0.01 vs. 0.23±0.02,P<0.05). GIOP+DMSOwas sig- nificantly lower than that in GIOP+SKN group (0.24±0.01 vs. 0.81±0.16,P<0.05). GIOP+DMSO+si-NC groupwas significantly higher than GIOP+DMSO+si-PCSK5 group (0.82±0.06 vs. 0.38±0.03,P<0.05). The Relative proteinexpression of GDF11 in PBS group was sig- nificantly lower than that in GIOP group (0.30±0.01 vs. 1.22±0.11,P<0.05). GIOP+DMSO group was significantly higher than GIOP+ SKN group (1.28±0.11 vs. 0.52±0.04,P<0.05). GIOP+DMSO+si-NC group was significantly lower than GIOP+DMSO+si-PCSK5 group (0.49±0.04 vs. 0.87±0.16,P<0.05).Conclusion Shikonin promotes bone metabolism in osteoporotic rats by regulating PCSK5/GDF11 pathway.