IL-4抑制COPD大鼠肺组织COX-2和PDGF的表达

目的探讨白细胞介素-4(IL-4)对慢性阻塞性肺疾病(COPD)大鼠模型建立的影响,以及COPD肺组织中环氧合酶-2(COX-2)和血小板源性生长因子(PDGF)的表达及IL-4对其表达的影响机制。方法用雄性Wistar大鼠建立吸烟大鼠COPD模型。随机分为对照组,模型组,IL-4组和地塞米松组。用免疫组化法和逆转录聚合酶联反应法(RT-PCR),检测肺组织中COX-2和PDGF-A及PDGF-B的表达情况。结果模型组COX-2和PDGF-A、-B表达明显增高;IL-4组和地塞米松组显著降低。结论IL-4和地塞米松可干预COPD模型的建立;COPD肺组织中COX-2和PDGF的表达显著增高,IL-4和地塞米松可明显降低其表达。     

温肾固疏方对PMOP大鼠骨密度及细胞因子表达的影响

通过观察温肾固疏方对去卵巢骨质疏松(PMOP)大鼠的骨密度及对白细胞介素-1β、肿瘤坏死因子-α、白细胞介素-6的血清含量和转化生长因子-β骨组织表达的影响,探讨其治疗骨质疏松的可能作用机制。将48只SPF级雌性SD大鼠分为6组:假手术组、模型组、雌激素组、温肾固疏方高、中、低剂量组。造模4周后开始给药,连续给药12周,酶联免疫法(ELISA)检测外周血清白细胞介素-1β(IL-1β)、肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)含量;q RT-PCR法检测骨组织转化生长因子-β(TGF-β)m RNA含量。与假手术组相比较,去势模型组大鼠骨密度(BMD)、TGF-β mRNA显著降低(p0.05),而IL-1β、TNF-α、IL-6均显著升高(p0.01),符合绝经后骨质疏松症改变;干预治疗后,与模型组比较,温肾固疏方高、中剂量组椎骨BMD显著升高(p0.05),IL-1β、TNF-α、IL-6显著减少(p0.05),温肾固疏方高剂量组TGF-β mRNA显著增加(p0.05)。温肾固疏方治疗骨质疏松的作用机制可能与其下调IL-1β、TNF-α、IL-6等促炎细胞因子的表达,抑制骨吸收;同时上调TGF-β等抑炎细胞因子的表达,促进骨形成有关。     

脾虚大鼠脑内IL-1β、IL-2 表达的变化及益气扶正中药的干预研究*

目的:研究脾虚模型大鼠脑内白细胞介素1 β(IL-1β)、白细胞介素2(IL-2)的活性表达,以及扶正益气中药的干预作用.方法:40只大鼠随机分成4组,正常组、模型组、治疗1组(四君子汤组)、治疗2组(玉屏风散组),每组各10只.采用苦降泻下、饮食失节加劳倦过度法建立大鼠脾虚模型,采用免疫组化法检测下丘脑腹侧核、海马CA1区的IL-1β和IL-2表达变化与四君子汤玉屏风散的治疗作用.结果:IL-1β在海马CA1区和下丘脑腹侧核表达明显降低,IL-2在海马CA1区和下丘脑腹侧核表达明显降低;四君子汤治疗组IL-1β和IL-2在上述脑区表达明显上升;玉屏风散治疗组IL-1β和IL-2在上述脑区表达呈紊乱变化现象.结论:益气扶正中药四君子汤、玉屏风散可能通过影响免疫器官、调控细胞因子IL-1β和IL-2活性表达而调节机体免疫功能.     

结直肠癌患者手术前后血清TNF-α, NO, IL-1β、IL-6水平变化及临床意义

目的:探索结直肠癌患者术前术后肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)、一氧化氮(nitric oxide,NO)、白细胞介素-1β(Interleukin-1Beta,IL-1β)、白细胞介素-6(interleukin-6,IL-6)表达水平的变化及其临床意义。方法:对本院75例结直肠癌患者分别采用硝酸还原法及双抗夹心ELISA法检测手术前后NO及TNF-α、IL-1β、IL-6表达水平的变化,同时将其与43例健康体检者相比较。结果:结直肠癌患者手术前血清中TNF-α、IL-1β、IL-6浓度(19.45±4.09,3.91±0.25,15.93±1.00)明显高于正常对照组(P0.05),而NO浓度(27.5±5.5)明显低于正常对照组(P0.05),手术治疗后7天,TNF-α、IL-1β、IL-6血清含量(12.31±3.89,1.41±0.33,9.30±2.11)明显降低(P0.05),而NO含量恢复正常水平。结论:血清中TNF-α、NO、IL-1β、IL-6浓度与结直肠癌密切相关,对TNF-α、NO、IL-1β、IL-6浓度进行联合诊断可作为结直肠癌早期诊断的参考指标。     

IL-6, IL-1β及TNF-α与大鼠骨质疏松形成的关系

目的:研究白细胞介素-6(IL-6)、白细胞介素-1β(IL-1β)及肿瘤坏死因子-α(TNF-α)与大鼠骨质疏松形成的关系,为研究细胞因子与骨质疏松之间的相关作用机制提供参考。方法:选择2015年1月至2015年11月我院采购的90只雌性大鼠作为研究对象,按照数字随机法将大鼠分成观察组(n=45)以及对照组(n=45)。观察组制成骨质疏松模型,对照组不作处理,对比两组局部骨密度,成骨细胞,骨小梁以及破骨细胞在视野面积中的比例,骨组织相关细胞因子水平,分析IL-6、IL-1β以及TNF-α水平与大鼠骨质疏松的相关性。结果:观察组椎体骨密度(BD)和椎间盘BD以及小关节BD均明显低于对照组,差异均有统计学意义(P0.05);观察组骨小梁和成骨细胞在视野面积中的比例明显低于对照组,而破骨细胞在视野面积中的比例明显高于对照组,差异均有统计学意义(P0.05);观察组IL-6和IL-1β以及TNF-α均明显高于对照组,差异有统计学意义(P0.05)。IL-6、IL-1β以及TNF-α水平与大鼠椎体BD、椎间盘BD以及小关节BD均呈明显负相关。结论:去卵巢大鼠的细胞因子与其骨质疏松具有紧密联系,表现在IL-6、IL-1β以及TNF-α水平与大鼠椎体BD、椎间盘BD以及小关节BD均呈明显负相关。     

基于IL-6/JAK2/STAT3信号通路研究岩白菜素对急性肝损伤大鼠的保护作用

基于IL-6/JAK2/STAT3信号通路探讨岩白菜素对四氯化碳(CCl_4)致大鼠急性肝损伤的保肝作用及其作用机制。60只SD大鼠随机分为正常组、模型组、水飞蓟素(120 mg/kg)组、岩白菜素低、中、高(20、40、80 mg/kg)剂量组,每组10只。水飞蓟素组、岩白菜素各剂量组大鼠按照10 mL/kg灌胃给药,正常组和模型组灌胃相应体积溶剂,每日1次,连续1周。末次给药2 h后,除正常组以外,其余各组腹腔注射25%四氯化碳(CCl_4)橄榄油溶液2 mL/kg,建立急性肝损伤大鼠模型。禁食不禁水,16 h后眼球取血,并收集肝脏。生化法测定血清中谷丙转氨酶(ALT)、谷草转氨酶(AST)、白蛋白(ALB)、丙二醛(MDA)、谷胱甘肽过氧化物酶(GSH-Px)以及超氧化物歧化酶(SOD)的水平或活性。酶联免疫吸附法(ELISA)测定检测肝组织中白细胞介素-6(IL-6)、肿瘤坏死因子(TNF-α)和白细胞介素-1β(IL-1β)的含量。采用HE染色观察肝组织的病理变化程度,免疫组化(IHC)观察肝组织中IL-6的表达水平,蛋白免疫印迹法(Western blot)检测IL-6/JAK2/STAT3通路相关蛋白的表达水平。实验结果表明,与模型组相比,岩白菜素各剂量组和水飞蓟素组大鼠肝组织炎症坏死和IL-6表达不同程度的减轻。岩白菜素可显著降低血清中的ALT、AST、MDA和肝组织中TNF-α、IL-6和IL-1β活性或水平,上调血清中ALB、SOD和GSH-Px的活性或水平,并且抑制IL-6/JAK2/STAT3通路相关蛋白的表达。综上所述,岩白菜素对CCl_4致急性肝损伤大鼠具有保护作用,其保肝机制可能与IL-6/JAK2/STAT信号通路介导的炎症反应和抗氧化有关。     

胆管癌组织中IL-6、COX-2与PGE2的表达及相关性研究

目的:检测胆管癌组织中白细胞介素-6(IL-6)、环氧化酶-2(COX-2)和前列腺素E2(PGE2)的表达,探讨其与胆管癌发生发展的意义。方法:应用免疫组化S-P法检测49例胆管癌组织和20例胆囊结石胆囊管组织中IL-6、COX-2和PGE2的表达情况。结果:IL-6在胆囊管组织和胆管癌中的表达率分别为40.0%和81.6%,差异具有统计学意义(P0.01);COX-2在胆囊管组织和胆管癌中的表达率分别为10%和69.4%,差异具有统计学意义(P0.01);PGE2在胆囊管组织和胆管癌中的表达率分别为35.0%和73.5%,差异具有统计学意义(P0.01)。IL-6和COX-2、COX-2和PGE2、IL-6和PGE2在胆管癌中的阳性表达呈显著正相关(r=0.37,P0.01;r=0.50,P0.01;r=0.31,P0.05)。结论:IL-6、COX-2与PGE2的过度表达共同参与胆管癌的进展。     

左归丸促进小鼠未成熟卵母细胞体外核成熟的实验研究

目的:研究左归丸对小鼠未成熟卵母细胞体外核成熟的影响。方法:制备左归丸含药血清,将生发泡(germinal vesicle,GV)期卵母细胞分别在不同采血时间获取的左归丸含药血清培养液中进行体外培养,观察左归丸含药血清对生发泡破裂(germinal vesicle breakdown,GVBD)和第一极体(the first polar body,PB1)排出的时效关系。结果:药物血清组卵母细胞GVBD的发生率高于正常血清组和对照组,于培养后4h差异最显著(P<0.01);药物血清组卵母细胞PB1的发生率高于正常血清组和对照组,于培养后18h差异最显著(P<0.01)。结论:2～2.5h左归丸含药血清对未成熟卵母细胞体外核成熟具有明显促进作用。     

骨髓基质细胞IL-1β、IL-6、SCF及TPO在老年多发性骨髓瘤组织中的表达及意义

目的:探讨老年多发性骨髓瘤患者骨髓基质细胞白细胞介素-1(IL-1β)、白细胞介素-6(IL-6)、肝细胞因子(SCF)、血小板生成素(TPO)水平及临床意义。方法:选择本院2011年1月-2014年6月收治的老年多发性骨髓瘤患者作为观察组,另选择同期参加体检的志愿者作为对照组。采集两组人员骨髓标本,制备总RNA、反转录反应、聚合酶链反应及PCR产物电泳检测等过程的测定两组患者IL-1β、IL-6、SCF、TPO水平。结果:观察组患者IL-1β、IL-6、SCF、TPO水平均明显高于对照组(P0.05);初发患者、复发患者及移植患者的IL-1β、IL-6比较无明显差异(P0.05)。移植组SCF水平显著低于初发组和复发组(t初移=4.967,t难移=5.169,P0.05);初发组TPO显著高于复发组和移植组(t初难=4.736,t初移=3.568,P0.05)。结论:老年多发性骨髓瘤患者骨髓基质细胞白细胞介素-1、白细胞介素-6、肝细胞因子、血小板生成素水平表达升高,在疾病的发生及发展过程中发挥重要作用。     

骨髓基质细胞IL-1beta、IL-6、SCF及TPO在老年多发性骨髓瘤组织中 的表达及意义

目的:探讨老年多发性骨髓瘤患者骨髓基质细胞白细胞介素-1(IL-1β)、白细胞介素-6(IL-6)、肝细胞因子(SCF)、血小板生成素(TPO)水平及临床意义。方法:选择本院2011年1月-2014年6月收治的老年多发性骨髓瘤患者作为观察组,另选择同期参加体检的志愿者作为对照组。采集两组人员骨髓标本,制备总RNA、反转录反应、聚合酶链反应及PCR产物电泳检测等过程的测定两组患者IL-1β、IL-6、SCF、TPO水平。结果:观察组患者IL-1β、IL-6、SCF、TPO水平均明显高于对照组(P<0.05);初发患者、复发患者及移植患者的IL-1β、IL-6比较无明显差异(P>0.05)。移植组SCF水平显著低于初发组和复发组(t初移=4.967,t难移=5.169,P<0.05);初发组TPO显著高于复发组和移植组(t初难=4.736,t初移=3.568,P<0.05)。结论:老年多发性骨髓瘤患者骨髓基质细胞白细胞介素-1、白细胞介素-6、肝细胞因子、血小板生成素水平表达升高,在疾病的发生及发展过程中发挥重要作用。     

IL-17 mediates estrogen-deficient osteoporosis in an Act1-dependent manner

Estrogen-deficient osteoporosis may be an inflammatory disorder and we therefore asked if IL-17 participates in its pathogenesis. Deletion of the principal IL-17 receptor (IL-17RA) protects mice from ovariectomy (OVX)-induced bone loss. Further supporting a central role of IL-17 in its pathogenesis, OVX-induced osteoporosis is prevented by a blocking antibody targeting the cytokine. IL-17 promotes osteoclastogenesis by stimulating RANK ligand (RANKL) expression by osteoblastic cells, mediated by the IL-17RA SEFIR/TILL domain. Estrogen deprivation, however does not enhance IL-17RA mRNA expression by osteoblasts or in bone, but augments that of Act1, an IL-17RA-interacting protein and signaling mediator. Similar to IL-17RA(-/-) mice, those lacking Act1 are protected from OVX-induced bone loss. Also mirroring IL-17RA-deficiency, absence of Act1 in osteoblasts, but not osteoclasts, impairs osteoclastogenesis via dampened RANKL expression. Transduction of WT Act1 into Act1(-/-) osteoblasts substantially rescues their osteoclastogenic capacity. The same construct, however, lacking its E3 ligase U-box or its SEFIR domain, which interacts with its counterpart in IL-17RA, fails to do so. Estrogen deprivation, therefore, promotes RANKL expression and bone resorption in association with upregulation of the IL-17 effector, Act1, supporting the concept that post-menopausal osteoporosis is a disorder of innate immunity.     

Effects of TGF-beta, TNF-alpha, IL-beta and IL-6 alone or in combination, and tyrosine kinase inhibitor on cyclooxygenase expression, prostaglandin E2 production and bone resorption in mouse calvarial bone cells

Cyclooxygenase-2 (COX-2) and tyrosine kinase, which are involved in the biosynthesis of prostaglandin E(2) (PGE(2)) in mouse calvarial osteoblasts, are stimulated by cytokine interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha) and/or interleukin-6 (IL-6). IL-1beta and IL-6 and, to a lesser extent, TNF-alpha, enhances COX-2 mRNA levels in calvarial osteoblasts. Simultaneous treatment with IL-6 and IL-1beta and TNF-alpha resulted in enhanced COX-2 mRNA levels accompanied by the cooperative stimulation of PGE(2) biosynthesis compared to cells treated with IL-1beta or TNF-alpha or IL-6 alone. In contrast, the presence of TGF-beta reduced COX-2 mRNA level, PGE(2) biosynthesis and bone resorption induced by IL-1beta, TNF-alpha, IL-6 or a combination thereof. However, neither IL-1beta, TNF-alpha, IL-6 nor a combination of IL-1beta, TNF-alpha, IL-6 enhanced COX-1 mRNA levels in calvarial osteoblasts. A novel Src tyrosine kinase inhibitor, Herbimycin A (HERB), reduced COX-2 mRNA levels as well as PGE(2) production induced by IL-1beta, TNF-alpha and IL-6 or a combination of IL-1beta, TNF-alpha, IL-6, whereas COX-1 mRNA levels remained unaffected. Finally, HERB was found to inhibit in vitro bone resorption. These results indicate that the cooperative effects of IL-beta, TNF-alpha, IL-6 on PGE(2) production are due to the enhanced expression of the COX-2 gene and that tyrosine kinase(s) are involved in COX-2 signal transduction in mouse calvarial osteoblasts. Thus, the Src family of kinase inhibitors may be useful in treating diseases associated with elevated bone loss.     

胆管癌组织白介素-6、环氧合酶-2和血管内皮生长因子的表达及临床意义

目的:探讨胆管癌组织白介素-6(IL-6)、环氧合酶-2(COX-2)和血管内皮生长因子(VEGF)的表达及临床意义。方法:将手术切除并经病理诊断确诊的胆管癌石蜡包埋标本80例纳为胆管癌组,另取癌旁正常胆管组织作为对照组,采用免疫组织化学SP法检测两组组织中IL-6、COX-2、VEGF的表达情况并做比较,分析胆管癌组织中VEGF、COX-2、IL-6阳性表达与临床病理特征关系,采用Spearman等级相关分析胆管癌组织中VEGF、COX-2、IL-6表达的相关性。结果:胆管癌组的VEGF、COX-2、IL-6阳性表达率均显著高于对照组,组间比较差异有统计学意义(P0.05)。胆管癌组织中VEGF、COX-2、IL-6阳性表达率与有无淋巴结转移、TNM分期、分化程度有关(P0.05),而与性别、年龄、肿瘤直径无关(P0.05),其中有淋巴结转移、TNM分期Ⅲ～Ⅳ期、低分化程度的胆管癌患者的VEGF、COX-2、IL-6阳性表达率高于无淋巴结转移、TNM分期Ⅰ～Ⅱ期、中高分化程度的胆管癌患者(P0.05)。Spearman等级相关分析显示,胆管癌组织中VEGF与COX-2、IL-6呈正相关(P0.05),COX-2与IL-6也呈正相关(P0.05)。结论:胆管癌组织IL-6、COX-2、VEGF均呈现高表达,并与胆管癌的生长、转移密切相关,检测IL-6、COX-2和VEGF有助于判断胆管癌疾病进展。     

Influence of Exercise on Bone Remodeling-Related Hormones and Cytokines in Ovariectomized Rats: A Model of Postmenopausal Osteoporosis

This study aims to explore the effects of exercise on postmenopausal osteoporosis and the mechanisms by which exercise affects bone remodeling. Sixty-three Wistar female rats were randomly divided into five groups: (1) control group, (2) sham-operated group, (3) OVX (Ovariectomy) group, (4) DES-OVX (Diethylstilbestrol-OVX) group, and (5) Ex-OVX (Exercise-OVX) group. The rat osteoporosis model was established through ovariectomy. The Ex-OVX rats were made to run 251.2 meters every day, 6 d/wk for 3 months in a running wheel. Trabecular bone volume (TBV%), total resorption surface (TRS%), trabecular formation surface (TFS%), mineralization rate (MAR), bone cortex mineralization rate (mAR), and osteoid seam width (OSW) were determined by bone histomorphometry. The mRNA and protein levels of interleukin-1β (IL-1β₂), interleukin-6 (IL-6), and cyclooxygenase-2 (Cox-2) were determined by in situ hybridization and immunohistochemistry, respectively. Serum levels of estrogen estradiol (E₂), calcitonin (CT), osteocalcin (BGP), and parathyroid hormone (PTH) were determined by ELISA assays. The investigation revealed that compared to the control and the sham-operated groups, the OVX group showed significantly lower levels of TBV%, E₂, and CT, but much higher levels of TRS%, TFS%, MAR, OSW, BGP, and PTH. The Ex-OVX group showed increased TBV% and serum levels of E₂ and CT compared to the OVX group. Ovariectomy also led to a significant increase in IL-1β mRNA and protein levels in the bone marrow and IL-6 and Cox-2 protein levels in tibias. In addition, the Ex-OVX group showed lower levels of IL-1 mRNA and protein, IL-6 mRNA, and Cox-2 mRNA and protein than those in the OVX group. The upshot of the study suggests that exercise can significantly increase bone mass in postmenopausal osteoporosis rat models by inhibiting bone resorption and increasing bone formation, especially in trabecular bones.     

益坤精胶囊对骨质疏松模型小鼠骨形态和血清中IL-6表达的影响

目的:观察益坤精胶囊对骨质疏松模型小鼠骨形态计量学指标及血清白介素-6(IL-6)的影响。方法:取60只C57雌性小鼠随机分为:模型组(等体积生理盐水)、雌激素组(尼尔雌醇,0.25 mg/kg)、益坤精胶囊高剂量组(1.44 g/kg)、中剂量组(0.72 g/kg)、低剂量组(0.36 g/kg)及假手术组(等体积生理盐水),各组灌胃均70 d。采用酶联免疫吸附测定(ELISA)法检测血清中IL-6浓度,BI-2000医学图像分析系统进行骨形态计量学指标检测,使用CT测量分析各组小鼠股骨远侧干骺端血管数量。结果:与假手术组比较,模型组骨小梁平均宽度、骨皮质平均厚度、骨小梁面积、成骨细胞数以及骨密度、骨血管数量均明显减小,而破骨细胞数、血清中IL-6的浓度明显上升(P0.05)。与模型组比较,雌激素组、益坤精胶囊高、中、低剂量组上述指标均明显改善(P0.05),且益坤精胶囊高剂量组与雌激素组疗效相当(P0.05)。结论:益坤精胶囊可明显改善骨质疏松模型小鼠的骨形态计量学指标,降低血清中IL-6水平,增加骨血管数量,且以1.44 g/kg益坤精胶囊灌胃效果最佳。     

成份输血对胃癌术后血清IL-6、IL-10、COX-2、PGE_2含量的影响

目的：观察围手术期成份输血对胃癌患者炎症反应的影响。方法：随机选择胃癌病人分为3组：对照组,压积红细胞组,全血组。分别采用ELISA法和放免法检测患者术前及术后低1、3、7、14天血清中IL-6、IL-10、COX-2及PGE2含量。结果：手术后第一周是感染发生的主要时期,两周后,炎症反应基本消失,输血能升高患者血清中的促炎因子,降低抗炎因子IL-10的表达,但相对于输异体全血,输成份血能降低血清中COX-2、PGE2、IL-6的含量,升高血清IL-10的含量。结论：胃癌患者围手术期输血能促进机体的炎症反应,成份输血致炎效果弱于输异体全血。     

IL-1 alpha stimulates the formation of osteoclast-like cells by increasing M-CSF and PGE2 production and decreasing OPG production by osteoblasts

Interleukin-1alpha (IL-1alpha) is one of the most potent bone-resorbing factors involved in the bone loss that is associated with inflammation. We examined the effect of the inflammatory mediator IL-1alpha on the expression of macrophage colony-stimulating factor (M-CSF), osteoprotegerin (OPG), and prostaglandin E2 (PGE2) in rat osteoblasts, and the indirect effect of IL-1alpha on the formation of osteoclast-like cells. Osteoblasts were cultured in alpha-minimum essential medium containing 10% fetal bovine serum with or without 100 units/ml of IL-1alpha for up to 14 days. The gene and protein expression of M-CSF and OPG were estimated by determining mRNA levels using the real-time polymerase chain reaction and protein levels using Western blot analysis. PGE2 expression was determined using an enzyme-linked immunosorbent assay. The formation of osteoclast-like cells was estimated using tartrate-resistant acid phosphatase (TRAP) staining of osteoclast precursors in culture with conditioned medium from IL-1alpha-treated osteoblasts and the soluble receptor activator of NF-kappaB ligand (RANKL). M-CSF and PGE2 expression in osteoblasts increased markedly in cells cultured with IL-1alpha, whereas OPG expression decreased. The conditioned medium containing M-CSF and PGE2 produced by IL-1alpha-treated osteoblasts and soluble RANKL increased the TRAP staining of osteoclast precursors. These results suggest that IL-1alpha stimulated the formation of osteoclast-like cells via an increase in M-CSF and PGE2 production, and a decrease in OPG production by osteoblasts.     

IL-6 receptor expression and IL-6 effects change during osteoblast differentiation

Studies of the effects of interleukin-6 on osteoblasts have yielded conflicting results. In several earlier in vitro studies it has been stated that IL-6 has no effects on osteoblasts unless soluble IL-6 receptor is added. These results are contradictory to the fact that IL-6 receptors are expressed in osteoblasts in vivo. In this study, MC3T3 preosteoblast cells and rat bone marrow stromal cells were cultured in bone inducing medium containing ascorbic acid, β-glycerophosphate or dexamethasone. We found that IL-6 receptor expression increased in both types of cells during in vitro differentiation. Furthermore in MC3T3 cells IL-6 decreased proliferation and enhanced expression of two osteoblast-specific differentiation markers, Runx2 and osteocalcin, in proper sequential order. Interestingly, in both cell types IL-6-induced apoptosis only in later culture stages. We also found in MC3T3 cells that IL-6 induced STAT3 activation was significantly higher in later culture stages, i.e. when IL-6 receptor expression was high. The present study shows that IL-6 receptor expression increases during in vitro osteoblast differentiation and that IL-6 functions as a differentiation regulator of preosteoblast cells and an apoptosis initiator in more mature cells.     

IL-6 Contributes to the Defective Osteogenesis of Bone Marrow Stromal Cells from the Vertebral Body of the Glucocorticoid-Induced Osteoporotic Mouse

Osteoporosis is one of the most prevalent skeletal system diseases. It is characterized by a decrease in bone mass and microarchitectural changes in bone tissue that lead to an attenuation of bone resistance and susceptibility to fracture. Vertebral fracture is by far the most prevalent osteoporotic fracture. In the musculoskeletal system, osteoblasts, originated from bone marrow stromal cells (BMSC), are responsible for osteoid synthesis and mineralization. In osteoporosis, BMSC osteogenic differentiation is defective. However, to date, what leads to the defective BMSC osteogenesis in osteoporosis remains an open question. In the current study, we made attempts to answer this question. A mouse model of glucocorticoid-induced osteoporosis (GIO) was established and BMSC were isolated from vertebral body. The impairment of osteogenesis was observed in BMSC of osteoporotic vertebral body. The expression profiles of thirty-six factors, which play important roles in bone metabolisms, were compared through antibody array between normal and osteoporotic BMSC. Significantly higher secretion level of IL-6 was observed in osteoporotic BMSCs compared with normal control. We provided evidences that IL-6 over-secretion impaired osteogenesis of osteoporotic BMSC. Further, it was observed that β-catenin activity was inhibited in response to IL-6 over-secretion. More importantly, in vivo administration of IL-6 neutralizing antibody was found to be helpful to rescue the osteoporotic phenotype of mouse vertebral body. Our study provides a deeper insight into the pathophysiology of osteoporosis and identifies IL-6 as a promising target for osteoporosis therapy.