Astragaloside I Stimulates Osteoblast Differentiation Through the Wnt/β‐catenin Signaling Pathway

Astragaloside I (As‐I), one of the main active ingredients in Astragalus membranaceus, is believed to have osteogenic properties, but this hypothesis has not been investigated in detail. In the present work, the As‐I‐induced osteogenic effects and its underlying mechanism were studied in MC3T3‐E1 cells. The results indicated that the cellular levels of ALP and extracellular matrix calcium increased in a dose‐dependent manner by As‐I. To clarify the mechanisms involved in this process, the effect of As‐I on the key osteogenic‐related genes was investigated. We found that As‐I stimulated the expression of β‐catenin and Runx2 in MC3T3‐E1 cells, which play central roles in the Wnt/β‐catenin signaling pathway, suggesting that As‐I could promote osteoblastic differentiation by regulating the Wnt/β‐catenin signaling pathway. Moreover, the osteogenic effect of As‐I could be inhibited by DKK‐1, which is the classical inhibitor of Wnt/β‐catenin‐signaling pathway. Furthermore, As‐I also increased BMP‐2, BGP and OPG/RANKL expression, which are also activated by Wnt/β‐catenin signaling pathway. Taken together, our findings show that As‐I stimulates osteoblast differentiation through the Wnt/β‐catenin signaling pathway, which also activates the BMP pathway and RANK pathway, thus highlighting the As‐I for pharmaceutical and medicinal applications such as treating bone disease. Copyright © 2016 John Wiley & Sons, Ltd.     

基于分子对接的方法探讨桑根酮C对MC3T3-E1细胞的作用

目的:观察桑根酮C(SanC)对地塞米松(DEX)作用下小鼠MC3T3-E1成骨细胞增殖与分化的影响,并探讨其作用机制。方法:将SanC与同源建模所得的Runt-相关转录因子2(Runx2)蛋白结构进行分子对接。不同浓度SanC(8,16,32μmol·L^-1)和1μmol·L^-1DEX共同作用MC3T3-E1细胞,而后采用细胞增殖-毒性检测试剂盒(CCK-8)法检测SanC对MC3T3-E1成骨细胞增殖影响。试剂盒测定MC3T3-E1成骨细胞碱性磷酸酶(ALP)活性和茜素红染色检测骨矿化结节的形成。采用实时荧光定量聚合酶链反应(Real-time PCR)检测Runt-相关转录因子2(Runx2),ALP,和锌指结构转录因子(Osterix)mRNA的表达水平。蛋白免疫印迹法(Western blot)检测Runx2蛋白表达。结果:SanC与Runx2对接打分为-9.78。与正常组比较,DEX组显著降低细胞存活率(P<0.01),其中7 d存活率差异达到最大;与DEX组比较,SanC能显著促进MC3T3-E1的细胞增值(P<0.01),其中32μmol·L^-1SanC作用细胞7 d增殖率差异达到最大。与正常组比较,DEX组Runx2,ALP和Osterix mRNA的表达均有一定程度升高(P<0.05);与DEX组比较,不同浓度SanC组依赖性上调Runx2,ALP和Osterix mRNA的表达(P<0.01)。与正常组比较,DEX组Runx2蛋白表达明显下降(P<0.05);与DEX组比较,SanC干预下细胞Runx2蛋白表达显著升高(P<0.01)。结论:桑根酮C能促进MC3T3-E1成骨细胞增殖、分化和矿化,其机制可能与上调Runx2表达有关。     

JNK通路对左归丸含药血清调控MC3T3 成骨细胞Runx2 mRNA表达的影响

目的:探讨c-Jun氨端激酶(JNK)信号通路在左归丸含药血清调控成骨前体细胞(MC3T3-E1)增殖和成骨特异转录因子核心结合因子(Runx2) mRNA表达中的作用.方法:以MC3T3-E1为研究对象,制备左归丸含药血清,选用JNK特异抑制剂SP 600125,实验分为空白对照组、SP 600125组、左归丸组、左归丸加SP 600125组、倍美力组、倍美力加SP 600125组.孵育48 h后,采用噻唑蓝(MTT)法检测SP600125对左归丸含药血清干预MC3T3-E1成骨前体细胞增殖作用的影响,采用Western blot法分析JNK蛋白磷酸化水平,采用Real Time RT-PCR法检测成骨细胞特异转录因子Runx2 mRNA表达情况.结果:与空白对照组比较,左归丸含药血清组显著促进细胞增殖,明显上调p-JNK蛋白和Runx2 mRNA表达(P＜0.01);SP600125显著抑制左归丸含药血清诱导的增殖和p-JNK蛋白表达(P＜0.01),对Runx2 mRNA表达的影响不显著.结论:JNK信号通路的激活可能参与了左归丸含药血清诱导的MC3T3-E1成骨前体细胞增殖,但左归丸含药血清诱导的Runx2mRNA高表达对JNK信号通路依赖不显著.     

Effects of Tilianin on Proliferation,Migration and TGF‐β/Smad Signaling in Rat Vascular Smooth Muscle Cells Induced with Angiotensin II

Flavonoid Tilianin was isolated from Dracocephalum moldavica, and its pharmacological mechanism on proliferation, migration and the TGF‐β/Smad signaling pathway in rat vascular smooth muscle cells (VSMCs) induced with Angiotensin II (Ang II) was systematically evaluated. Primary rat VSMCs were stimulated with Ang II to induce proliferation. The cells were then treated with Tilianin for 24 or 48 h. MTT assay and Transwell assays were used to evaluate the effects of Tilianin on proliferation and migration. The expression of intracellular proliferating cell nuclear antigen (PCNA), intercellular adhesion molecule‐1 (ICAM‐1) and vascular cell adhesion molecule‐1 (VCAM‐1) were measured by immunohistochemistry as verification of effects on proliferation and migration. The expression of TGF‐β1, Smad2 and Smad3 mRNA was measured by qRT‐PCR, and the expression of TGF‐β1 and P‐Smad2/3 protein was measured by Western blotting. The results show that Tilianin can inhibit proliferation and expression of intracellular PCNA in VSMCs induced with Ang II, in a dose‐dependent manner. Tilianin also mediates a dose‐dependent inhibition of migration and the expression of intracellular ICAM‐1, VCAM‐1, MMP‐2 and MMP‐9. Furthermore, TGF‐β1, Smad2, Smad3, Smad2/3 and P‐Smad2/3 in Ang II‐induced VSMCs are suppressed by Tilianin. The inhibitory effects of Tilianin support its use in the suppression and treatment of atherosclerosis. Copyright © 2017 John Wiley & Sons, Ltd.     

Stimulation of osteoblastic differentiation and mineralization in MC3T3-E1 cells by yeast hydrolysate

In a previous study, it was reported that yeast hydrolysate (YH) was effective in promoting bone growth in Sprague‐Dawley (SD) rats. To further clarify the mechanism of YH, the effects of YH on proliferation, differentiation and gene expression in vitro were investigated using osteoblastic cell lines (MC3T3‐E1). Cell proliferation increased significantly as much as 110% of the basal value when cells were treated with 100 µg/mL of YH. Alkaline phosphatase (ALP) activity increased significantly with a YH concentration of 25–100 µg/mL, and the activity increased 152% that of the control at 100 µg/mL. The calcium content increased as much as 129% at 100 µg/mL YH. The gene expression levels of ALP and collagen type II (COL II) significantly increased approximately 1.3‐fold and 1.7‐fold of control, respectively, at 100 µg/mL. YH increased significantly the mRNA level of bone sialoprotein (BSP) but not in a dose‐dependent manner. The mRNA levels of bone morphogenetic proteins (BMP)‐2, BMP‐4, collagen type I (COL I) and osteonectin (ON) did not increase. In summary, YH increased the proliferation of osteoblasts and directly stimulated ALP and bone matrix proteins (e.g. BSP, COL II), and these increases trigger osteoblastic differentiation (e.g. mineralized nodule formation). Copyright © 2010 John Wiley & Sons, Ltd.     

β‐Eudesmol Induces JNK‐Dependent Apoptosis through the Mitochondrial Pathway in HL60 Cells

β‐eudesmol, a natural sesquiterpenol present in a variety of Chinese herbs, is known to inhibit the proliferation of human tumor cells. However, the molecular mechanisms of the effect of β‐eudesmol on human tumor cells are unknown. In the present study, we report the cytotoxic effect of β‐eudesmol on the human leukemia HL60 cells and its molecular mechanisms. The cytotoxic effect of β‐eudesmol on HL60 cells was associated with apoptosis, which was characterized by the presence of DNA fragmentation. β‐eudesmol‐induced apoptosis was accompanied by cleavage of caspase‐3, caspase‐9, and poly (ADP‐ribose) polymerase; downregulation of Bcl‐2 expression; release of cytochrome c from mitochondria; and decrease in mitochondrial membrane potential (MMP). Activation of c‐Jun N‐terminal kinases (JNK) mitogen‐activated protein kinases was observed in β‐eudesmol‐treated HL60 cells, and the inhibitor of JNK blocked the β‐eudesmol‐induced apoptosis, downregulation of Bcl‐2, and the loss of MMP. These data suggest that β‐eudesmol induces apoptosis in HL60 cells via the mitochondrial apoptotic pathway, which is controlled through JNK signaling. Copyright © 2012 John Wiley & Sons, Ltd.     

Soy Isoflavone Glycitin (4'‐Hydroxy‐6‐Methoxyisoflavone‐7‐D‐Glucoside) Promotes Human Dermal Fibroblast Cell Proliferation and Migration via TGF‐β Signaling

Glycitin is a soy isoflavone that exhibits antioxidant, antiallergic, and anti‐osteoporosis activities. We investigated the effects of glycitin on dermal fibroblast proliferation and migration. Treatment of primary dermal fibroblasts with glycitin increased cell proliferation and migration. In addition, treatment with 20 μM glycitin for 24 h induced the synthesis of collagen type I and type III at both the mRNA and protein levels. Fibronectin was also increased by 20% after treatment. Matrix metalloproteinase‐1 collagenase was decreased in the media after 24‐h incubation with glycitin, and the synthesis of transforming growth factor‐beta (TGF‐β) mRNA increased approximately twofold in cells following glycitin treatment. Phosphorylation of Smad2 and Smad3 increased after 1 h of glycitin treatment, and phosphorylation continued for 24 h. Furthermore, the phosphorylated form of AKT was increased in glycitin‐treated cells after 3 h and remained higher for 24 h. Thus, glycitin treatment produces anti‐aging effects including increased total collagen in the culture media, decreased elastase, and decreased β‐galactosidase. Together, these results indicate that glycitin stimulates TGF‐β secretion, and the subsequent autocrine actions of TGF‐β induce proliferation of fibroblasts, ultimately protecting skin cells from aging and wrinkling. Copyright © 2015 John Wiley & Sons, Ltd.     

Gleditsia sinensis thorn extract inhibits human colon cancer cells: the role of ERK1/2, G2/M‐phase cell cycle arrest and p53 expression

The thorns of Gleditsia sinensis are used as a medicinal herb in China and Korea. However, the mechanisms responsible for the antitumor effects of the water extract of Gleditsia sinensis thorns (WEGS) remain unknown. HCT116 cells treated with the WEGS at a dose of 800 μg/mL (IC₅₀) showed a significant decrease in cell growth and an increase in cell cycle arrest during the G2/M‐phase. G2/M‐phase arrest was correlated with increased p53 levels and down‐regulation of the check‐point proteins, cyclinB1, Cdc2 and Cdc25c. In addition, treatment with WEGS induced phosphorylation of extracellular signal‐regulated kinase (ERK), p38 MAP kinase and JNK (c‐Jun N‐terminal kinases). Moreover, inhibition of ERK by treatment of cells with the ERK‐specific inhibitor PD98059 blocked WEGS‐mediated p53 expression. Similarly, blockage of ERK function in the WEGS‐treated cells reversed cell‐growth inhibition and decreased cell cycle proteins. Finally, in vivo WEGS treatment significantly inhibited the growth of HCT116 tumor cell xenografts in nude mice with no negative side effects, including loss of body weight. These results describe the molecular mechanisms whereby the WEGS might inhibit proliferation of colon cancer both in vitro and in vivo, suggesting that WEGS has potential as an anticancer agent for the treatment of malignancies. Copyright © 2010 John Wiley & Sons, Ltd.     

Genistein suppresses adipogenesis of 3T3‐L1 cells via multiple signal pathways

Genistein, an isoflavone, was shown to have therapeutic effects for obesity, diabetes and cardiovascular diseases. This study investigated the effect and underlying mechanism of genistein on adipogenesis in 3T3‐L1 preadipocytes. Genistein inhibited lipid accumulation and decreased the nonesterified fatty acid (NEFA) content of 3T3‐L1 on day 6 after the induction of differentiation with methylisobutylxanthine, dexamethasone and insulin (MDI). Genistein recovered nitric oxide (NO) release suppressed by MDI and the results were consistent with the expression of endothelial NO synthase (eNOS) assayed by western blotting. Pretreatment with genistein inhibited the phosphorylation of p38 mitogen‐activated protein kinase (p38 MAPK) stimulated with 10 µg/mL of insulin. Furthermore, genistein inhibited the expression of fatty acid synthase (FAS) from 178% of the MDI group to 74%. SB203580, a p38 inhibitor, mimicked the FAS inhibition effect of genistein, suggesting that the inhibitory effect of genistein on FAS was partially via the p38 pathway. On the other hand, genistein abolished the phosphorylation of janus‐activated kinase 2 (JAK2) in response to MDI. AG490, a JAK2 inhibitor, suppressed the expression of CCAAT/enhancer binding protein alpha (C/EBPα), a marker of adipocyte differentiation. The findings suggest that genistein attenuates the differentiation of 3T3‐L1 involving multiple signal pathways. Copyright © 2008 John Wiley & Sons, Ltd.     

补肾健脾活血方对去卵巢大鼠BMP2/Smad信号通路的影响

目的:研究补肾健脾活血方对去卵巢大鼠骨形态发生蛋白2(BMP2)/Smad信号通路的影响。方法:72只6月龄雌性SD大鼠,随机分为假手术组(24只),手术组(48只),双侧卵巢切除法造模,术后3个月两组各随机选取12只检测骨密度验证造模成功。手术组剩余的36只大鼠随机分为双侧卵巢切除模型组(OVX),补肾健脾活血方组(BSJPHX,给药剂量2.979 g·kg~(-1)),阿仑膦酸钠维D3片(Ⅱ)组(ALN,给药剂量1.02 mg·kg~(-1)),假手术组,OVX组给与等体积生理盐水灌胃。12周后处死各组大鼠,双能X射线法检测大鼠全身骨密度,生物力学试验进行胫骨三点弯曲试验,实时荧光定量聚合酶链式反应(Real-time PCR)检测BMP2,Smad1,Runt相关转录因子2(Runx2),骨保护素(OPG)基因的表达,蛋白免疫印迹法(Western blot)检测BMP2,p-Smad1,Runx2,OPG蛋白的表达。结果:造模3个月后,与假手术组比较,OVX组大鼠骨密度明显降低,最大载荷及刚度均降低,BMP2,Smad1,Runx2,OPG基因和蛋白表达水平显著降低(P0.05);给药3个月后,与OVX组比较,BSJPHX组,ALN组骨密度均明显增高,最大载荷及刚度均增加,能显著提高BMP2,Smad1,Runx2,OPG基因和蛋白表达水平(P0.05)。结论:补肾健脾活血方既能通过调控BMP2/Smad通路的信号转导,又能上调OPG的表达,这可能是补肾健脾活血方防治绝经后骨质疏松症的机制之一。     

Anthocyanidin attenuates myocardial ischemia induced injury via inhibition of ROS‐JNK‐Bcl‐2 pathway: New mechanism of anthocyanidin action

Despite treatment options available to date, myocardial ischemia (MI) remains the leading cause of death worldwide. Studies are focused on finding effective therapeutic strategies against MI injury. Growing interest has been developed in natural compounds possessing medicinal properties with scarcer side effects. Here, we have evaluated the cardioprotective potential of anthocyanidin against MI injury and explored its underlying protective mechanism. Left anterior descending coronary artery was ligated to induce MI in mice. Neonatal mice cardiomyocytes were treated with H₂O₂ to induce oxidative stress (a major contributor to MI injury) in vitro. Anthocyanidin pretreatment significantly reduced the infarct size, preserved the cell viability, and protected against ischemia‐induced cardiac injury in treatment groups compared with the H₂O₂‐treated group in vitro. Measurement of reactive oxygen species (ROS) validated the strong antioxidant potential of anthocyanidin, as significant reduction in oxidative stress was observed in anthocyanidin‐pretreated groups. Mechanistically, pretreatment with anthocyanidin significantly subdued the activation of JNK (to p‐JNK) and elevated Bcl‐2 levels. Both in vivo and in vitro findings suggest that anthocyanidin can induce a state of myocardial resistance against ischemic insult. We have provided the experimental evidence for inhibition of ROS/p‐JNK/Bcl‐2 pathway being the underlying mechanism of action of anthocyanidin. Our results support the use of anthocyanidin as therapeutic strategy against MI injury.     

(+)‐Isobicyclogermacrenal and spathulenol from Aristolochia yunnanensis alleviate cardiac fibrosis by inhibiting transforming growth factor β/small mother against decapentaplegic signaling pathway

Cardiac fibrosis contributes to both systolic and diastolic dysfunction in many cardiac pathophysiologic conditions. Antifibrotic therapies are likely to be a crucial strategy in curbing many fibrosis‐related cardiac diseases. In our previous study, an ethyl acetate extract of a traditional Chinese medicine Aristolochia yunnanensis Franch. was found to have a therapeutic effect on myocardial fibrosis in vitro and in vivo. However, the exact chemicals and their mechanisms responsible for the activity of the crude extract have not been illustrated yet. In the current study, 10 sesquiterpenoids ( 1 – 10 ) were isolated from the active extract, and their antifibrotic effects were systematically evaluated in transforming growth factor β 1 (TGFβ1)‐stimulated cardiac fibroblasts and NIH3T3 fibrosis models. (+)‐Isobicyclogermacrenal ( 1 ) and spathulenol ( 2 ) were identified as the main active components, being more potent than the well‐known natural antifibrotic agent oxymatrine. Compounds 1 and 2 could inhibit the TGFβ1‐induced cardiac fibroblasts proliferation and suppress the expression of the fibrosis biomarkers fibronectin and α‐smooth muscle actin via down‐regulation of their mRNA levels. The mechanism study revealed that 1 and 2 could inhibit the phosphorylation of TGFβ type I receptor, leading to the decrease of the phosphorylation levels of downstream Smad2/3, then consequently blocking the nuclear translocation of Smad2/3 in the TGFβ/Smad signaling pathway. These findings suggest that 1 and 2 may serve as promising natural leads for the development of anticardiac fibrosis drugs.     

Stimulation of osteoblastic differentiation and inhibition of interleukin‐6 and nitric oxide in MC3T3‐E1 cells by pomegranate ethanol extract

In this experiment, we studied the effects of pomegranate fruit extract (PE) on the function of osteoblastic MC3T3‐E1 cells and the production of local factors in osteoblasts. PE (16～250 µg/ml) significantly increased the growth of MC3T3‐E1 cells (P < 0.05). Moreover, PE (50 µg/ml) caused a significant elevation of alkaline phosphatase (ALP) activity and collagen content in the cells. We then examined the effect of PE on the TNF‐α‐induced production of interleukin‐6 (IL‐6) and nitric oxide (NO) in osteoblasts. Treatment with PE (10～50 µg/ml) decreased the TNF‐α (10^?10 M)‐induced production of IL‐6 and NO in osteoblasts. Copyright © 2008 John Wiley & Sons, Ltd.     

(−)‐Epigallocatechin‐3‐Gallate Ameliorates Photodynamic Therapy Responses in an In Vitro T Lymphocyte Model

(?)‐Epigallocatechin‐3‐gallate (EGCG), the most abundant polyphenolic constituent in green tea, is known as a powerful antioxidant but concomitantly possesses a prooxidant property. We investigated the effect of EGCG on phloxine B (PhB)‐induced photocytotoxicity in human T lymphocytic leukemia Jurkat cells. EGCG significantly potentiated PhB‐induced photocytotoxic effects, including the inhibition of cell proliferation, DNA fragmentation, and caspase‐3 activity induction in Jurkat cells. Catalase attenuated the enhanced cytotoxicity by EGCG, suggesting the involvement of extracellularly produced hydrogen peroxide. Indeed, EGCG significantly enhanced extracellular hydrogen peroxide formation induced by photo‐irradiated PhB. The EGCG also enhanced intracellular reactive oxygen species accumulation, c‐Jun N ‐terminal kinase (JNK) phosphorylation, and interferon‐γ (IFN‐γ) gene expression, all of which are involved in PhB‐induced apoptosis. Taken together, our data suggest that EGCG is capable of potentiating photodynamic therapy responses, presumably through the intracellular oxidative stress‐sensitive JNK/IFN‐γ pathway by exogenous hydrogen peroxide formation. Copyright © 2014 John Wiley & Sons, Ltd.