Panax Notoginseng Saponins suppresses TRPM7 via the PI3K/AKT pathway to inhibit hypertrophic scar formation in vitro

BackgroundHypertrophic scar (HS) formation, a type of dermal fibroproliferative condition, is a frequent complication in wound healing resulting from burns, severe trauma, and surgical procedures. The effects of Panax Notoginseng Saponins (PNS) on the HS formation remain relatively under-explored. Hence, this study was intended to interrogate anti-apoptosis and anti-fibrosis effects of PNS on the hypertrophic scar fibroblasts (HSFs) during HS formation and assess the involvement of TRPM7 and PI3K/AKT signaling pathway.MethodsUsing MTT and CCK-8 assays, we evaluated cell cytotoxicity and cell viability. Collagen I/III (col 1/3) and α-SMA expression levels were assessed through immunofluorescence and western blot, and cell migration, cell apoptosis and cell cycle were examined with applications of wound healing, TUNEL staining and flow cytometry. TRPM7, PI3K/AKT, TGF-β1 and related-proteins were quantified using RT-qPCR and western blot.ResultsPNS administration could suppress TRPM7 expression and the viability of HSFs in a dose-dependent manner. Moreover, PNS could restrain the HS formation and ECM deposition by decreasing col 1/3 and α-SMA synthesis, suppressing cell migration, and boosting apoptosis and G1 arrest. Notably, this study revealed that PNS inhibited PI3K/AKT activation in HSFs. Besides, knockdown of TRPM7 enhanced therapeutic effects of PNS on HSFs, but overexpression markedly reversed above mentioned effects of PNS on HSFs.ConclusionThis study suggested that PNS hampered scar formation might via inhibiting ECM and stimulating cell apoptosis by modulating the PI3K/AKT signaling. Overall, these findings in the present study could support the use of PNS for preventing HS formation, and TRPM7 may be a novel molecular target for treating HS.     

Synergistic inhibition of thyroid cancer by suppressing MAPK/PI3K/AKT pathways

Background

Although a wide spectrum of inhibitors of the MEK/ERK and PI3K/AKT pathways have been discovered and entered clinical trials, the effects of their individual use in thyroid cancer were often disappointing. We hypothesized that dual targeting of these two pathways would be a safe and effective strategy against aggressive thyroid cancers.

Methods

We examined the antiproliferative effects of the MEK/ERK inhibitor AZD6244 and the PI3K/AKT inhibitor GDC0941, individually or in combination, on thyroid cancer cells harboring both the BRAF^V600E and PIK3CA mutations. The effects of drug exposure on both total and phosphorylated (p-) forms of AKT and ERK were monitored by Western blotting analysis. Effects of these inhibitors on cell-cycle progression and apoptosis were measured by flow cytometry and DNA-fragmentation analyses, respectively.

Results

We observed significant toxicities to viability of cells with low concentrations of AZD6244 or GDC0941, which were synergistic when the two inhibitors were used in combination (P < 0.01). AZD6244 abrogated p-ERK and GDC0941 abrogated p-AKT levels, confirming their expected target effects. Unexpectedly, monotherapy with AZD6244 resulted in activation of the PI3K signaling pathway in some cancer cell lines and co-exposure to AZD6244 and GDC0941 was necessary to suppress both pathways. Flow cytometry showed G1 arrest. DNA fragmentation analysis showed an increased apoptosis of cells dually treated with the two inhibitors.

Conclusion

Concomitant suppression of MEK/ERK and PI3K/AKT pathways by AZD6244 and GDC0941 abrogates compensatory mechanisms of tumor survival and causes synergistic cytotoxicity in thyroid cancer cells.     

IGF-1调控乳腺癌VEGF-C表达的实验研究

目的:探讨胰岛素样生长因子-1(insulin-like growth factor-1,IGF-1)对乳腺癌MDA-MB-231细胞株的血管内皮生长因子-C(vascular endothelial growth factor-C,VEGF-C)表达的调控及其相关信号传导通路。方法:应用实时定量PCR和Western印迹技术检测IGF-1刺激前后目的基因VEGF-C mRNA及其蛋白在乳腺癌细胞中表达的变化,检测细胞内相关信号传导分子Akt、ERK1/2蛋白及其磷酸化表达改变。结果:IGF-1显著促进乳腺癌细胞株的VEGF-C表达(P0.05);VEGF-C表达与IGF-1间呈浓度依赖关系;在IGF-1作用下,p-Akt及p-ERK1/2表达显著增加(P0.05)。结论:IGF-1能显著促进乳腺癌MDA-MB-231细胞株的VEGF-C表达,信号传导分子p-Akt与p-ERK1/2可能在其中起着重要的介导作用。     

IGF-1在运动系统中的应用及研究进展

胰素样生长因子-1(IGF-1)是由70个氨基酸组成的具有内分泌、自分泌及旁分泌特性的单链多肽,分子量约为7.5 ku,主要由人肝细胞合成和分泌,对机体生长发育起着重要调节作用,是软骨合成代谢的主要因子,能够保持软骨细胞在正常软骨中的代谢动态平衡,并且在体内改善软骨的愈合.还能定向诱导脂肪干细胞向软骨细胞方向分化.能显著刺激肌腱细胞的DNA和Ⅰ型胶原的合成,以自分泌和旁分泌的形式调节骨骼细胞的功能,促进成骨细胞增殖、分化和募集,抑制细胞凋亡,刺激骨胶原的合成和DNA的转录,抑制胶原的降解,增加骨基质沉积.IGF-1可以增加骨骼肌的蛋白合成,减少骨骼肌的蛋白降解.具有促进肌肉组织利用葡萄糖,促进受伤骨骼肌愈合的能力.     

The lysosomal trafficking regulator is necessary for normal wound healing

Non-healing wounds are a major threat to public health throughout the United States. Tissue healing is complex multifactorial process that requires synchronicity of several cell types. Endolysosomal trafficking, which contributes to various cell functions from protein degradation to plasma membrane repair, is an understudied process in the context of wound healing. The lysosomal trafficking regulator protein (LYST) is an essential protein of the endolysosomal system through an indeterminate mechanism. In this study, we examine the impact of impaired LYST function both in vitro with primary LYST mutant fibroblasts as well as in vivo with an excisional wound model. The wound model shows that LYST mutant mice have impaired wound healing in the form of delayed epithelialization and collagen deposition, independent of macrophage infiltration and polarisation. We show that LYST mutation confers a deficit in MCP-1, IGF-1, and IGFBP-2 secretion in beige fibroblasts, which are critical factors in normal wound healing. Identifying the mechanism of LYST function is important for understanding normal wound biology, which may facilitate the development of strategies to address problem wound healing.     

IGF-1R抗体对兔耳瘢痕组织的影响

目的:观察胰岛素样生长因子-1受体(IGF-1R)抗体对兔耳增生性瘢痕组织的影响。方法:建立兔耳增生性瘢痕动物模型,21天后瘢痕局部注射不同浓度的IGF-1R抗体或生理盐水,连续7天,观察1个月。分别对瘢痕增生指数(hypertrophicindex,HI)、成纤维细胞数和胶原含量的变化进行比较。结果:一定剂量IGF-1R抗体组HI值、成纤维细胞数量以及胶原含量比对照组减少(P<0.01或0.05)。结论:IGF-1R抗体能抑制兔耳瘢痕组织增生。     

重组人生长激素对裸鼠肝癌移植瘤生长转移的实验研究

目的:研究重组人生长激素(recombinant hunman growth hormone,rhGH)对裸鼠肝癌移植瘤生长和转移能力的影响及相关信号转导通路的变化。方法:通过RNA干扰技术抑制MHCC-97H肝癌细胞中胰岛素样生长因子-1受体(insulin-like growth factor-1 receptor,IGF-1R)的表达。建立裸鼠皮下和原位肝癌移植模型;研究IGF-1R基因沉默前后,rhGH对裸鼠肝癌移植瘤成瘤、生长和转移的影响,并用Western印迹法检测PI-3K信号转导通路中,信号分子AKT的蛋白表达和磷酸化水平。结果:注射rhGH可使荷瘤裸鼠体重明显增加,肝癌原位移植瘤体积显著增大(P0.05)。IGF-1R基因沉默后,裸鼠皮下移植瘤的成瘤率、原位肝癌接种模型中的肝癌移植瘤体积均显著减小(P0.05)。对PI-3K信号通路的研究显示,rhGH能显著促进MHCC-97H肝癌细胞信号分子AKT磷酸化,IGF-1R沉默后AKT磷酸化水平明显降低(P<0.05)。结论:rhGH在体内具有显著促进荷瘤裸鼠体重增加及移植瘤生长的作用;但并不促进肝癌的转移。IGF-1R基因沉默后,rhGH对裸鼠移植瘤的成瘤和促生长作用明显减弱。而PI-3K信号通路在rhGH促肝癌生长中发挥重要的介导作用。     

SDF-1、CXCR4及ERK1／2在病理性瘢痕中的表达及临床意义

目的：检测病理性瘢痕组织中SDF-1,CXCR4及ERK1／2的表达并探讨其在病理性瘢痕中的相互作用机制。方法：采用免疫组织化学SABC法检测66例病理性瘢痕,25例非病理性瘢痕及27例正常皮肤中SDF-1,CXCR4及ERK1／2的表达。结果：与正常皮肤及非病理性瘢痕相比,SDF-1、CXCR4及ERK1／2三者在病理性瘢痕中均高表达（P〈0．05）;在病理性瘢痕中,SDF—1与ERK1／2的表达呈正相关关系（r=0．293,P〈0．05）,CXCR4和ERK1／2的表达呈正相关关系（r=0．284,P〈O．05）结论：SDF-1／CXCR4生物轴在病理性瘢痕形成过程中可能通过调节ERK1／2途径从而在病理性瘢痕的增生中发挥重要作用。     

Basic fibroblast growth factor (bFGF) alleviates the scar of the rabbit ear model in wound healing

Studies suggest a possible antiscarring effect of basic fibroblast growth factor (bFGF) during wound healing. However, little is known about the precise pathological mechanisms of bFGF. In particular, there is only limited information available about the mechanism of exogenous administration of bFGF to scar formation. To investigate the effect of bFGF on the hypertrophic scar in the rabbit ear model and to clarify the mechanisms of bFGF on treatment for scar in wound healing, the rabbit ear model of wound healing was created and treated topically with bFGF once daily for 3 months; then we examined the changes of macroscopic and histopathological characteristics of scars and the expression of collagen and collagenase-1 (matrix metalloproteinase-1). The results of macroscopic and histologic characteristics revealed a significant difference between scars treated with bFGF and control scars. The expression of collagen in the scars treated with bFGF was decreased, as compared with the scars treated with saline. Further study revealed that bFGF could remarkably enhance expression of matrix metalloproteinase-1. bFGF could improve the quality of wound healing and remarkably alleviate the scar in the rabbit ear model in wound healing, which suggests that bFGF exerted a net negative effecton scar formation in wound healing. The evidence should contribute to a better understanding of the biological activities of bFGF during hypertrophic scar formation.     

HGF通过P13K/AKT信号通路上调SMMC-7721细胞Mcl-1的表达

目的 探讨HGF是否上调SMMC-7721细胞抗凋亡蛋白Mcl-1的表达以及HGF是通过哪条信号途径调节MCl-1.方法 人肝癌细胞SMMC-7721进行实验;采用RT-PCR检测HGF受体c-Met在SMMC-7721细胞的表达情况;用Western blot方法 检测MAPK和P13K/AKT磷酸化以及Mcl-1蛋白的表达;用信号通路阻断剂处理SMMC-7721细胞,检测HGF是通过哪条信号途径调节Mcl-1.结果 人肝癌细胞SMMC-7721表达HGF受体C-Met;HGF能够激活MAPK、PI3K/AKT信号转导途径;HGF能够上调SMMC-7721细胞Mcl-1表达;进一步用特异的抑制剂阻断MAPK途径后,并不能改变HGF对Mcl-1的上调作用,而阻断PI3K/AKT途径后,HGF对Mcl-1的上调作用被抑制.结论 HGF对Mcl-1的上调作用是通过PI3K/AKT途径介导的.     

Down‐regulation of mir‐27b promotes angiogenesis and fibroblast activation through activating PI3K/AKT signaling pathway

To study the effects of mir‐27b on angiogenesis and fibroblast activation and to explore its further mechanism. Humanmicrovascular endothelial cell (HMEC)‐1 and humannormal skin fibroblast (BJ) cells were treated with mir‐27b inhibitor negative control reagent, mir‐27b inhibitor, LY294002, and mir‐27b inhibitor + LY294002, respectively. 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) was used to detect the T‐cell proliferation. The migration ability was detected by Scratch assays. The angiogenesis of HMEC‐1 cells was observed by in vitro tube formation assay. The mRNA and protein expression of vascular endothelial growth factor (VEGF) in HMEC‐1 cells and the mRNA and protein expression of collagen I, collagen III, α‐SMA, and MMP1 in BJ cells were detected by quantitativereal‐time polymerase chain reaction (qRT‐PCR) and Western blot, respectively. Meanwhile, the PI3K/protein kinase B (AKT) pathway‐related proteins were also detected by Western blot. The proliferation, migration, angiogenesis, the mRNA and protein expression of VEGF and the protein expression of p‐PI3K and p‐AKT in HMEC‐1 cells were increased after treated with mir‐27b inhibitor. Meanwhile, the proliferation, migration, and the protein expression of collagen I, collagen III, α‐SMA, MMP1, p‐PI3K, and p‐AKT in BJ cells were increased after treated with mir‐27b inhibitor. However, the angiogenesis and fibroblast activation of mir‐27b inhibitor was reversed by LY294002, and the activate effect to PI3K/AKT pathway was also inhibited. Down‐regulation of mir‐27b could promote angiogenesis and fibroblast activation, and its mechanism is related to activate PI3K/AKT signaling pathway.     

血小板衍生生长因子对成纤维细胞合成胶原的影响

目的 探讨血小板衍生生长因子（ＰＤＧＦ－ＡＢ）促进伤口愈合的作用机理及其在瘢痕增生中的作用。方法 取体外培养的人正常皮肤及增生性瘢痕成纤维细胞,用原位杂交法观察ＰＤＧＦ对两种细胞表达Ｐｒｏα１（Ⅲ）ｍＲＮＡ的影响。结果;ＰＤＧＦ－ＡＢ对两种成纤维细胞表达Ｐｒｏ α１（Ⅲ）ｍＲＮＡ均有明显促进作用,且均呈剂量依赖性关系,但作用有差异。     

Effect of Piascledine-bacterial nanocellulose combination on experimental cutaneous wound healing in rat: Histopathological,biochemical and molecular studies

The study investigated the wound healing potential of Piascledine (an avocado/soybean mixture) alone and in combination with bacterial nanocellulose on rat cutaneous wounds. Full-thickness excisional wounds (2 cm in diameter) were induced on the backs of 60 Sprague–Dawley rats, divided into four groups, treated with daily topical application of bacterial nanocellulose (BNC), Piascledine 10% (PSD 10%) and Piascledine+bacterial nanocellulose (PSD + BNC) (10 mg/disk) and normal saline (control) for 20 days. Wounds were monitored daily, and at 10, 20 and 30 days post-injury (DPI), tissue samples were collected for biochemical, histopathological and molecular analyses. Treated rats with PSD and PSD + BNC showed a significant decrease in the wound area compared with other groups. PSD and particularly PSD + BNC modulated inflammation, improved fibroplasia and angiogenesis and scar tissue formation at short term. At the long term, they reduced the scar tissue size and improved collagen fibres alignment, tissue organization and remodelling as well as re-epithelialization. PSD enhanced matrix metalloproteinase-3 (MMP-3) gene expression, collagen and glycosaminoglycans (GAGs) synthesis and decreased tissue inhibitor of metalloproteinase-1 (TIMP-1) gene expression at various stages of wound healing. The study concluded that topical application of Piascledine, particularly in combination with bacterial nanocellulose, promotes wound healing activity by modulating inflammation, regulating MMP-3 expression and enhancing collagen and GAGs synthesis.     

PTEN regulates matrix synthesis in adult human chondrocytes under oxidative stress

Phosphatase and tensin homologue deleted on chromosome 10 (PTEN) was identified as an important tumor suppressor gene. PTEN functions as a negative regulator of phosphoinositol‐3‐kinase (PI3K)‐Akt and MEK/ERK signaling. The PI3K‐Akt pathway is critical for cell survival, differentiation, and matrix synthesis. Oxidative stress is considered a critical factor in the onset and progression of osteoarthritis (OA). Therefore, we investigated the function of PTEN in OA chondrocytes under oxidative stress. Chondrocytes were treated with insulin‐like growth factor‐1 (IGF‐1) and/or tert‐butyl hydroperoxide (tBHP), which causes oxidative stress. The expression levels of type2 collagen (Col2a1) and aggrecan were analyzed by real‐time PCR, and phosphorylation of Akt and ERK1/2 was analyzed by Western blotting. Chondrocytes were treated with PTEN‐specific small interfering RNA (siRNA), as well as IGF‐1 and/or tBHP. PTEN and IGF‐1 expressions in OA chondrocytes were increased. The downregulation of PTEN expression increased the expression levels of Col2a1 and aggrecan, and increased proteoglycan synthesis under oxidative stress. Oxidative stress decreased the phosphorylation of Akt and increased that of ERK1/2. The downregulation of PTEN expression increased Akt phosphorylation, but did not increase that of ERK 1/2. Our results suggest that PTEN regulates matrix synthesis via the PI3K‐Akt pathway under oxidative stress. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:231–237, 2014.     

碱性成纤维细胞生长因子对兔耳创面愈合过程中瘢痕形成的影响

目的 探讨碱性成纤维细胞生长因子(bFGF)对兔耳瘢痕模型的影响作用.方法 建立48个兔耳增生性瘢痕模型,将其随机分为bFGF治疗组与磷酸盐缓冲液(PBS)对照组,观察bFGF对创面愈合过程中瘢痕形成的影响.结果 形态学分析结果显示治疗组3个月后瘢痕外观、厚度及质地均优于对照组,表现出良好的愈合质量;对照组羟脯氨酸(HPr)表达较高,且随时间表现为增高趋势,伤后3个月达到高峰;而bFGF治疗组HPr表达均有不同程度的下降;逆转录-聚合酶链反应(RT-PCR)结果显示bFGF可以抑制CO Ⅰ mRNA的表达,但对COⅢmRNA表达无明显影响;Western blot结果显示bFGF可以促进MMP-1的合成,且随着时间延长表现为增高趋势,具有一定的时间相关性.结论 bFGF可以通过增加MMP-1合成、促进胶原蛋白降解而减少瘢痕的形成.     

特异性抑制髓母细胞瘤1型胰岛素生长因子受体信号通路后的差异性基因表达

目的 应用聚合酶链反应(PCR)芯片技术观察特异性抑制髓母细胞瘤细胞1型胰岛素生长因子受体(IGF-1R)信号通路的差异性基因表达,探讨IGF-1R在髓母细胞瘤细胞增殖中的作用.方法 体外培养髓母细胞瘤Doay细胞株,使用不同终质量浓度NVP-ADW742作用48 h和24 h后,检测细胞增殖和凋亡,分别使用IGF-1R酪氨酸蛋白激酶抑制剂NVP-ADW742终质量浓度为0、0.5、1.0、2.0、5.0、10.0、20.0、50.0μmol/L作用48 h后检测细胞存活率,以及终质量浓度为0.1、1.0、2.0、5.0、10.0μmol/L作用24 h后检测凋亡率,应用PCR芯片技术检测IGF-1R信号通路的差异性基因表达,并采用Western blot检测其蛋白表达.结果 在对应浓度的NVP-ADW742作用下Doay细胞的存活率分别为95.95%、93.95%、91.97%、86.60%、70.57%、15.01%、1.63%(P＜0.05),凋亡率分别为6.92%、8.83%、11.22%、17.27%、29.98%(P＜0.05),两者呈剂量依赖性,其浓度越高,抑制和促凋亡作用越强;在PCR芯片检测有14个差异表达基因;Western blot检测表明在2μmol/L的NVP-ADW742作用下,随时间延长PI3K、Akt、p38、GSK-3β和bcl-2蛋白表达逐渐下调.结论 髓母细胞瘤中IGF-1R信号通路异常可以促进肿瘤细胞的增殖,利用功能性PCR芯片可以有效地检测肿瘤细胞中相关基因在肿瘤增殖和凋亡中的作用.     

氧化应激介导的Ras-ERK信号通路活化参与醛固酮诱导的肾小球系膜细胞增殖

目的 探讨氧化应激介导的Ras-胞外信号调节激酶(ERK1/2)信号通路活化在醛同酮( ALDO)诱导的系膜细胞增殖中的作用.方法 体外培养人肾小球系膜细胞,应用3H-胸腺嘧啶(3H-TdR)掺入法和细胞计数测定系膜细胞增殖;Western印迹检测Ki-RasA、c-Raf、MEK1/2和ERK1/2活化.结果 ALDO可显著促进系膜细胞增殖,抗氧化剂乙酰半胱氨酸(NAC)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)显著抑制ALDO诱导的系膜细胞增殖(均P＜ 0.01).ALDO刺激系膜细胞3h,活化的Ki-RasA、c-Raf、MEK1/2和ERK1/2表达显著增强,分别是对照组的4.05倍、3.62倍、4.52倍和3.40倍(均P＜0.01).抗氧化剂NAC几乎完全阻断ALDO诱导的Ki-RasA、c-Raf、MEK1/2和ERK 1/2活化(均P＜0.01).Ki-RasA siRNA可呈浓度依赖性降低系膜细胞Ki-RasA表达,并显著抑制ALDO诱导的Ki-RasA活化及系膜细胞增殖(P＜0.01).c-Raf抑制剂GW5074和MEK1/2抑制剂PD98059亦显著抑制ALDO诱导的系膜细胞增殖,其抑制率均达到65％(P＜0.01).Ki- RasA siRNA不能降低ALDO诱导的磷酸肌醇-3激酶( PI3K)磷酸化.联合应用PI3K抑制剂LY294002和MEKl/2抑制剂PD98059可完全阻断ALDO诱导的系膜细胞增殖(P＜0.01).结论 ALDO可通过氧化应激活化Ki-RasA-c-Raf-MEK-ERK信号通路.同时阻断ERK1/2和PI3K信号通路可完全抑制ALDO诱导的系膜细胞增殖.