过氧化物酶体增殖物激活受体γ激动剂对转化生长因子β1诱导皮肤成纤维细胞作用的影响

目的 观察过氧化物酶体增殖物激活受体γ(PPARγ)激动剂对转化生长因子(TGF)-β1诱导成纤维细胞(Fb)转分化及对胶原牛成作用的影响.方法 体外培养成人正常皮肤Fb,免疫荧光细胞化学法观察PPARγ配体15-脱氧前列腺素J2(15d-PGJ2)、曲格列酮对TGF-β1诱导的α平滑肌动蛋白(α-SMA)表达的影响,Western blot检测15d-PGJ2、曲格列酮对TGF-β1诱导的α-SMA及Ⅰ型胶原蛋白表达的影响,噻唑蓝(MTT)比色法观察对Fb增殖活性的影响.结果 与TGF-β1诱导组比较,10μmoL/L曲格列酮、10 μmol/L 15d-PGJ2预处理组的α-SMA表达量显著减少(P<0.01),抑制效应分别为31%、57%;预处理组的Ⅰ型胶原表达量也屁著减少(P<0.01),抑制效应分别为57%、38%.曲格列酮、15d-PGJ2对Fb的增殖活性影响分析,各实验组与对照组比较差异无统计学意义(P>0.05).结论 PPARγ激动剂能抑制TGF-β1诱导的人正常皮肤Fb的转分化和Ⅰ型胶原合成增多的效应,具有抗瘢痕的潜在作用.     

过氧化物酶体增殖物激活受体γ激动剂拮抗人皮肤成纤维细胞转化生长因子β1机制研究

目的 了解过氧化物酶体增殖物激活受体γ(PPARγ)激动剂拈抗TGF-β1促皮肤瘢痕化的效应机制.方法 体外培养正常成人皮肤Fb,根据培养基中所加刺激物不同分为空白对照组(无血清DMEM培养基),TGF-β1组(DMEM培养基加入含终浓度10 ng/mL TGF-β1作用48 h),曲格列酮组(DMEM培养基加入含终浓度10μmol/L曲格列酮作用2 h,再加入10 ng/mL TGF-β1作用48h),15-脱氧前列腺素J2(15d-PGJ2)组(DMEM培养基加入含终浓度10 μmol/L 15d-PGJ2作用2 h,再加入10 ng/mL TGF-β1作用48 h).应用蛋白质印迹法检测结缔组织生长因子(CTGF)的表达,实时荧光RT-PCR检测CTGF、基质金属蛋白酶1(MMP-1)及血小板源性生长因子(PDGF)的mRNA水平变化.对数据进行单因素方差分析.结果 TGF-β1组的CTGF蛋白和mRNA表达水平均高于空白对照组,曲格列酮组和15d-PGJ2组的CTGF蛋白及mRNA表达水平低于TGF-β1组.空白对照组、TGF-β1组、曲格列酮组、15d-PGJ 2组MMP-1 mRNA表达水平分别为1.281±0.195、0.193±0.051、0.417±0.043、0.485±0.027,其中TGF-β1组低于空白对照组(F=12.811,P＜0.01),曲格列酮组、15d-PGJ2组高于TGF-β1组(F=12.811,P值均小于0.01).空白对照组、TGF-β1组、曲格列酮组、15d-PGJ2组PDGF mRNA表达水平分别为0.349±0.057、1.044±0.237、0.677±0.055、0.511±0.017,其中TGF-β1组高于空白对照组(F=16.848,P＜0.01),曲格列酮组、15d-PGJ2组低于TGF-β1组(F=16.848,P值均小于0.01).结论 激活后的PPARγ对TGF-β1下游反应因子CTGF的抑制作用,可能是其拮抗TGF-β1促皮肤瘢痕化的主要机制,而对细胞因子MMP-1、PDGF的影响可能也是其机制之一.     

过氧化物酶体增殖物激活受体-γ激动剂心肌保护作用机制的研究进展

背景过氧化物酶体增殖物激活受体（peroxisome proliferator-activated receptors,PPARs）主要参与和能量代谢及炎症反应相关的基因转录。其1亚型除作为治疗2型糖尿病的降糖靶点外,在心肌缺血／再灌注损伤（myocardial ischemia／reperfusion injury,MI／RI）中也具有关键作用,是减轻MI／RI、维持心脏功能的重要因子。目的探究过氧化物酶体增殖物激活受体-γ（peroxisome proliferator-activatedreceptor-γ,PPAR-γ）激动剂在MI／RI中心肌保护作用的相关机制。内容从PPAR-γ及其激动剂和相关实验研究等方面进行综述,PPAR-y激动剂能够通过依赖和不依赖PPAR-γ两条途径减少心肌梗死面积,改善心脏功能,发挥减轻MI／RI的作用,其中涉及抗炎、抗氧化、抗凋亡等多种重要保护机制。趋向深入研究PPAR激动剂减轻MI／RI的具体机制可为临床提供新的心肌保护策略。     

过氧化物酶体增殖物激活受体-γ配体抗肿瘤机制的研究进展

过氧化物酶体增殖物激活受体(PPAR-γ)及其配体已成为肿瘤基础研究的热点之一,文中从细胞分化、细胞增殖、细胞凋亡、血管形成及肿瘤侵袭性等方面综述了PPAR-γ配体抗肿瘤机制的研究进展。     

过氧化物酶体增殖物激活受体γ在脓毒症中的研究进展

背景 现已证实脓毒症是由感染因素诱发的全身性炎症反应综合征,在病程中表现为机体和病原体相互作用导致的促炎和抗炎反应不平衡. 目的 过氧化物酶体增殖物激活受体-γ(peroxisome proliferator activated receptor-γ,PPAR-γ)作为一种配体激活的核受体转录因子,与配体结合后作用于炎性信号转录途径的多个环节,抑制炎症反应,进而对脓毒症有一定的保护作用.因此,了解PPAR-γ在脓毒症中的研究现状以及未来发展趋势是十分必要的. 内容 PPAR-γ在缓和自身免疫性疾病、抗炎、抑制超敏反应、抗肿瘤及移植排斥中发挥重要的作用.针对PPAR-γ在脓毒症发病机制及治疗的研究作一综述. 趋向 PPAR-γ已成为炎症研究的方向,由于PPAR-γ结构与功能的复杂性,其作用机制尚未完全清楚,但随着对PPAR-γ研究的深入,有望为临床提供新的治疗方案.     

冻结肩病理改变及过氧化物酶体增殖剂激活受体-γ激动剂治疗作用的研究

背景:冻结肩是一种以肩关节疼痛和活动受限为主要特征的疾病,目前病因不明,治疗效果欠佳。目的:研究转化生长因子-β1(TGF-β1)对大鼠肩关节囊纤维化及炎症反应等病理改变的影响,以及过氧化物酶体增殖剂激活受体-γ(PPAR-γ)激动剂对大鼠冻结肩的治疗作用,为临床治疗冻结肩提供新思路。方法:利用TGF-β1诱导人皮肤成纤维细胞(HSF)异常纤维化,PPAR-γ激动剂三萜类化合物(CDDO-IM)作为治疗药物,检测细胞增殖、迁移情况及细胞外基质蛋白的表达情况。向SD大鼠的肩关节腔注射TGF-β1过表达的腺病毒构建大鼠冻结肩模型。2周后,其中一半大鼠用罗格列酮灌胃饲养2周,作为罗格列酮治疗组。检测大鼠肩关节活动度,利用ELISA检测关节腔炎症因子,HE染色和免疫组织化学法检测大鼠肩关节囊组织细胞外基质蛋白的表达情况。结果:在细胞实验中,TGF-β1组的增殖率为83.6%,TGF-β1+CDDO-IM组增殖率为19.3%(P<0.01);TGF-β1组的迁移率为84.9%,TGF-β1+CDDO-IM组迁移率为44.1%(P<0.05);TGF-β1能够诱导HSF增殖、迁移及异常纤维化。动物实验成功构建了TGF-β1诱导的大鼠冻结肩模型,免疫组织化学结果提示,罗格列酮能够抑制大鼠冻结肩的炎症形成,减少基质蛋白生成,重塑纤维组织结构。结论:冻结肩的病理改变主要是纤维细胞异常增生,炎症细胞浸润,纤维结构紊乱,而PPAR-γ激动剂可以缓解大鼠冻结肩关节僵硬,减弱炎症反应,抑制异常纤维化。     

过氧化物酶体增殖物激活受体γ激动剂对肝星状细胞增殖的影响

目的 观察过氧化物酶体增殖物激活受体γ（PPARγ）激动剂对肝星状细胞增殖的影响，探讨其抗肝纤维化的可能作用机制。方法 利用胶原酶原位灌注梯密度离心方法分离大鼠肝星状细胞（HSC），利用噻唑蓝（MTT）比色法、流式细胞技术检测曲格列酮、15-脱氧-前列腺素J2（15-d-PGJ2）对HSC增殖及细胞周期的作用。结果 MTT检测表明曲格列酮、15-d—PGJ2在5～100μmoL／L浓度范围内可显著抑制HSC的增殖，与对照组比较P〈0．01；流式细胞检测表明25、50μmoL／L的曲格列酮可显著降低HSCS期细胞数量，降低细胞增殖指数，与对照组比较，差异有统计学意义（P〈0．05）。结论 PPARy激动剂通过影响HSC的增殖而发挥其抗肝纤维化作用。     

表皮生长因子对小鼠创面组织过氧化物酶体增殖物激活受体β的调节作用

目的 了解小鼠创面外用冻干鼠表皮生长因于(mEGF)后,过氧化物酶体增殖物激活受体β(PPAR-β)表达量的变化及对创面愈合的影响. 方法 于70只BALB/c小鼠背部脊柱两侧各制作1个1.5 cm×0.5 cm全层皮肤缺损创面,将左侧创面设为实验组、右侧创面作为对照组.实验组创面滴加mEGF溶液(5μg/mL)、对照组创面滴加生理盐水.(1)伤后7、11、16 d各取20只小鼠,评估创面愈合率.(2)伤后1、3、7、11、14、18 d切取创缘组织(每时相点创面数为10个),采用免疫组织化学染色法检测PPAR-β蛋白表达,原位杂交法检测PPAR-β mRNA表达量,结果均用积分吸光度(IA)值表示.对实验数据行t检验. 结果 (1)创面愈合率:伤后7、11、16 d,实验组创面愈合率均明显高于对照组(t值分别为3.03、6.05、11.90,P值均小于0.01).(2)免疫组织化学检测:伤后早期PPAR-β蛋白主要表达于2组剖面内芽组织Fb以及创缘KC胞核中,创面上皮化后主要表达于新生上皮及其下层Fb中,创面修复后表达逐渐减弱.实验组伤后各时相点PPAR-β蛋白表达量明显高于对照组(t值为2.15～7.37,P ＜0.05或P ＜0.01),其中伤后3d达高峰[IA值为(3.46±1.33)×103],此时对照组IA值为(2.35±1.09) ×103.(3)原位杂交:伤后2组创面PPAR-β mRNA表达均开始上调,主要阳性表达部位为创面Fb及创缘KC胞质,持续至创面上皮化基本完成时,表达量开始下降.实验组创面各时相点PPAR-β mRNA表达量均明显高于对照组(t值为2.35～6.64,P＜0.05或P ＜0.01),其中伤后3 d达峰值[IA值为(7.3±2.6)×106],此时对照组IA值为(4.5±3.0)×106. 结论 外用mEGF可上调小鼠创面组织中PPAR-β表达并促进创面愈合.     

过氧化物酶体增殖物激活受体-γ在神经病理性疼痛中作用的研究进展

神经病理性疼痛（NP）由躯体感觉神经系统的损伤或疾病引起，其病理机制复杂，主要与神经结构及功能异常有关，现有治疗手段难以取得满意效果。随着对过氧化物酶体增殖物激活受体-γ（PPAR-γ）的深入研究，其在神经炎症、氧化应激、离子通道、线粒体功能、神经保护等方面的作用陆续被发现，并有望成为疼痛预防与治疗新靶点。本文就PPAR-γ在NP中的作用及机制作一综述，以期为NP的临床治疗提供新思路。     

过氧化物酶体增殖物激活受体γ配体抑制大鼠肝纤维化的实验研究

目的 研究过氧化物酶体增殖物激活受体γ(peroxisome proliferator activated receptorgamma,PPARγ)配体对大鼠肝纤维化的作用.方法 将Wistar大鼠40只随机分为两组,对照组(20只)和罗格列酮组(20只).所有动物使用饮水中加人质量比0.3‰硫代乙酰胺的方法 制作肝纤维化模型.对照组喂饲普通颗粒饲料.罗格列酮组喂饲含200 ppm罗格列酮的颗粒饲料.喂饲6个月后,用RT-PCR方法 检测肝纤维化大鼠肝脏PPARγ、TGF-β 1 及Ⅰ型前胶原mRNA表达,用Westernblot法检测PPARγ、TGF-β 1 、Ⅰ型胶原及α平滑肌肌动蛋白(α-SMA)表达,用Van Gieson(VG)染色的方法 检测肝组织切片的胶原表达情况.结果 罗格列酮组与对照组相比,PPARγmRNA表达显著增强(t=6.93,P<0.01),TGF-β 1 mRNA(t=3.89,P<0.01)和Ⅰ型前胶原mRNA表达显著降低(t=5.67,P<0.01).PPARγ、TGF-β 1 及Ⅰ型胶原蛋白表达所得结果 与RT-PCR结果 相一致.罗格列酮组与对照组相比,α-SMA表达显著降低(t=3.12,P<0.01).罗格列酮组肝组织切片的胶原染色低于对照组(t=3.47,P<0.01).结论 PPARγ配体能够抑制大鼠纤维化肝脏的胶原产生,在体内具有一定的抗肝纤维化作用.     

The Peroxisome Proliferator Activator Receptor Alpha/Delta Agonists Linoleic Acid and Bezafibrate Upregulate Osteoblast Differentiation and Induce Periosteal Bone Formation In Vivo

We showed previously that some actions of prostaglandin E₂ (PGE₂) on bone are caused by its degradation product, PGA₂, which mediates its effects via a class of nuclear receptors known as the peroxisome proliferator activator receptors (PPARs), suggesting that the PPARs may be involved in the regulation of bone formation. The aims of this study were to determine the effects of PPARα/δ agonists on bone in vitro and in vivo. PPAR agonists were examined in vitro using the fibroblastic colony-forming unit (CFU-f) assay. The PPARα/δ agonists linoleic acid (LA) and bezafibrate (Bez) were then administered to intact male rats by daily s.c. injection for 12 weeks with either vehicle (10% dimethyl sulfoxide), LA (0.3 mg/kg), or Bez (1 mg/kg). CFU-f assays were performed on stromal cells ex vivo. Bone mineral density (BMD) and serum markers of formation and resorption were measured. Bone histomorphometry was performed at cancellous and cortical bone sites. PPARα/δ agonists increased significantly the number of osteoblastic colonies as demonstrated by increased alkaline phosphatase activity, collagen production, and calcification. This increase was typically equal to or greater than that achieved with the known bone anabolic agent PGE₂. In intact male rats, LA and Bez increased metaphyseal BMD by 7% and 11%, respectively. Increased BMD was associated with an increase in total bone area, although no changes were observed in bone formation rate within the trabecular compartment. Serum osteocalcin and osteoprogenitor numbers were increased, whereas there was no change in either tartrate-resistant acid phosphatase 5b or osteoclast number. Both LA and Bez increased cortical bone area by approximately 38%, periosteal perimeter by 15%, and periosteal bone formation by 221% and 140%, respectively. There was no effect on medullary cavity area or endocortical perimeter. These data suggest that PPARα/δ may have roles in bone anabolism, specifically in the regulation of periosteal bone formation. They are potential therapeutic targets for osteoporosis therapy.     

Selective Agonists of Nuclear Retinoic Acid Receptor Gamma Inhibit Growth of HCS-2/8 Chondrosarcoma Cells

Chondrosarcoma is the second most common primary bone sarcoma. Treatment of chondrosarcoma is limited to surgery due to radiation and chemotherapy resistance of this cancer. An ideal treatment for chondrosarcoma would be a well-tolerated, minimally invasive local or systemic treatment modality to halt or slow tumor growth prior to resection of local, unresectable local, or metastatic disease. Palovarotene, an agonist of nuclear retinoic acid receptor γ (RARγ) has shown therapeutic action for treatment of heterotopic ossification and osteochondroma without serious adverse effects in animal models. We hypothesized that selective agonists of RARγ would have an inhibitory effect on chondrosarcoma. All human chondrosarcoma specimens expressed RARγ as determined by immunohistochemical staining. The ΗCS-2/8 chondrosarcoma cell line, established from low-grade human chondrosarcoma, was used to examine the actions of RARγ agonists. In ΗCS2/8 pellet cultures, RARγ agonist treatment reduced the mass size and significantly decreased total glycosaminoglycan, protein amounts, and gene expression levels of cartilage matrix molecules when compared with control groups. Systemic treatment with RARγ agonists significantly inhibited the growth of ΗCS-2/8 cell transplants in vivo. Furthermore, local injection of RARγ agonist-loaded poly-lactic acid nanoparticles induced regression of the mass size of the transplants. Histologic analysis demonstrated that RARγ agonist treatment inhibited cell proliferation activity and stimulated encapsulation of the tumor. These findings indicate that RARγ agonists, including palovarotene, may have an anti-tumor effect on low-grade chondrosarcomas. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:1045-1051, 2020     

Topical Immunomodulation in Dermatology: Potential of Toll-like Receptor Agonists

BACKGROUND: Topical immunomodulators include both immunostimulatory and immunosuppressive agents. If successful, topical immunotherapy may represent an important improvement in the therapy of inflammatory dermatoses, viral infections, and cancers of the skin and genital mucosa. Topical immunotherapy using obligate contact sensitizers such as diphencyprone or dinitrochlorobenzene has been used against viral (e.g., common warts) and autoimmune diseases (e.g., alopecia areata). RESULTS: Newer agents such imidazoquinolines (imiquimod and resiquimod) act by cytokine secretion from monocytes/macrophages (interferon-alpha, interleukin-12, tumor-necrosis factor-alpha). The locally generated immune milieu leads to a Th1-dominance and cell-mediated immunity that have been clinically used to treat viral infections such as human papillomavirus, herpes simplex virus, and mollusca. Although these agents improve antigen presentation by dendritic cells, they also act on B cells leading to the synthesis of antibodies such as IgG2a. We have also introduced this treatment against cancerous lesions including initial squamous cell and basal cell carcinoma in immunocompetent and immunosuppressed patients. We provide examples of successful treatment of squamous cell cancer using topical imiquimod. CONCLUSION: The available and additional Toll-like receptor agonists will help to improve the specific dermatologic therapy. Topical immunotherapy with both immunostimulatory and immunosuppressive agents bears potential for effective and patient friendly treatment of inflammatory, infectious, and cancerous skin diseases. Long-term evaluation will define the tolerability and safety profile of these novel topical agents.     

过氧化物酶体增殖激活物受体-γ在肾细胞癌中的表达及其意义

目的观察过氧化物酶体增殖激活物受体(PPAR)-γ在肾细胞癌中的表达,探讨其意义。方法应用逆转录聚合酶链反应(RT-PCR)、免疫组织化学和Western blot从RNA及蛋白水平检测正常肾组织、肾癌组织和肾细胞株HK-2、HMCC;肾癌细胞株786-O、A498中PPAR-γ表达。结果肾癌组织、肾组织及细胞株中PPAR-γ mRNA普遍表达,肾癌中PPAR-γ蛋白表达量为正常肾的7.0~10.7倍;肾癌组织PPAR-γ阳性率为98.3％,肾组织中为60.0％,其表达强度差异有显著性(t=7.888,P<0.01)。PPAR-γ在肾癌的细胞核和细胞质中均表达;PPAR-γ表达和肾癌的分级、分期明显相关。结论核内受体PPAR-γ在人肾癌组织及肾癌细胞株中呈上调表达,提示PPAR-γ基因的激活可能是肾细胞癌治疗的一种新的方法。     

Transforming Growth Factor- β Type II Receptor Is Infrequently Expressed in Human Breast Cancer

Abstract: TGFβ has been shown to suppress tumor growth in vitro through interaction with TGFβ type II receptor (TGFβ-RII). Although a significant percentage of breast carcinomas have been shown to express TGFβ, TGFβ expression was not found to influence survival of patients with breast cancer. In order to determine whether the lack of influence of TGFβ expression on the biologic behavior of breast cancer is due to lack of or infrequent expression of TGFβ-RII, we studied the expression of TGFβ-RII in 11 1 cases of invasive breast carcinoma by immunohistochemistry. The percent of breast cancer cells which stained for TGFβ-RII was subjectively scored as 0 (negative), >10%, 10–25%. 25–50%, and >50%. Of the invasive breast carcinomas, 81 (73%) were completely negative, 22 (20%) had 40% of the cells positive, and only 3 (3%) had >50% of the cells positive for TGFβ-RII. In benign breast tissue in the same tissue sections, myoepithelial cells were always positive for TGFβ-RII, whereas stromal cells were negative, and benign epithelial cells were rarely positive. We conclude that TGFβ-RII is consistently expressed in myoepithelial cells of the human breast, and rarely in epithelial cells, and that the infrequent expression of TGFβ-RII by invasive breast carcinomas, may explain why TGFβ expression does not appear to influence the outcome of patients with breast cancer.     

Alpha-2 Adrenergic Receptor Agonists: A Review of Current Clinical Applications

The α-2 adrenergic receptor agonists have been used for decades to treat common medical conditions such as hypertension; attention-deficit/hyperactivity disorder; various pain and panic disorders; symptoms of opioid, benzodiazepine, and alcohol withdrawal; and cigarette craving.¹ However, in more recent years, these drugs have been used as adjuncts for sedation and to reduce anesthetic requirements. This review will provide an historical perspective of this drug class, an understanding of pharmacological mechanisms, and an insight into current applications in clinical anesthesiology.Key Words: Procedural sedation, General anesthesia, Alpha-2 agonists, Clonidine, DexmedetomidineIn early scientific theory of adrenergic mechanisms, it was believed that adrenergic receptors were classified into 2 groups: those whose actions resulted in either excitation or inhibition of effector cells.² This theory was the accepted concept until Ahlquist² demonstrated that there were 2 subtypes of receptors in the class, which he termed α and β (2 Further study led researchers to discover that one of the α receptors inhibited neurotransmitter release from the presynaptic neuron.³ The α-receptor antagonists prazosin and yohimbine were used to further subclassify these receptors as α-1 and α-2.⁴ Later, many α-2 adrenergic agonists were developed for use in the clinical setting, including their use as anesthesia adjuncts. The use of α-2 agonists as adjuncts gained popularity when early reports by Brodsky and Bravo⁵ found that withholding a single dose of clonidine prior to anesthesia caused a patient to experience an acute hypertensive crisis. It was discovered that α-2 agonists produce effects within both the central and peripheral nervous systems. Centrally within the locus ceruleus, for example, α-2 agonists are able to produce sedation, analgesia, and euphoric effects and partially block acute withdrawal symptoms in chronic opioid users.⁴ More potent α-2 selective drugs, such as dexmedetomidine, have been formulated for clinical use as sole sedative agents or as adjuncts to drastically reduce the patient''s requirement for additional sedatives or general anesthetics. Also, α-2 agonists are gaining popularity in children''s hospitals throughout the United States as a preventative measure of and treatment modality for emergence delirium after general anesthesia.⁶

Table 1.

Open in a separate windowAdrenergic Receptor Subtypes and Their Physiologic Functions     

过氧化物酶体增殖物激活受体α在结直肠癌发病机制中的作用

目的探讨过氧化物酶体增殖物激活受体α（PPARα）在结直肠癌发病机制中的作用。方法对PPARα与结直肠癌的发病机制相关研究的文献进行综述。结果PPARα在结直肠癌发病机制中对结直肠癌细胞增殖、凋亡、分化的作用仍存在争议。结论PPARα有可能参与了结直肠癌细胞增殖、分化、凋亡等的调控过程,但其具体作用机制以及其上、下游的信号通路仍不清楚。此外,PPARα可能参与了结直肠癌部分化疔药物的耐药机制,但其作用也不甚明了。因此,需要更多的研究工作来进一步探究PPARα与结直肠癌的关系：     

肝细胞分离技术的研究进展

肝细胞移植在治疗急性肝衰竭和遗传代谢性肝病等方面有着十分广阔的应用前景。但肝细胞分离技术仍不完善,需进行深入研究和探讨,以提高细胞的活性和数量,保留细胞功能。文章就肝细胞基本的分离方式及主要实验物种的相关分离方法的进展进行综述。