碱性成纤维生长因子对皮肤损伤修复作用的研究进展

皮肤损伤是临床常见疾病之一,大多由撕裂、割伤或挫伤等急性创伤导致。在皮肤损伤修复过程中,多种细胞通过分泌细胞因子参与创面愈合,如碱性成纤维生长因子(fibroblast growth factor 2,FGF2或bFGF)、血小板源性生长因子(platelet-derived growth factor,PDGF)和转化生长因子β(transforming growth factor-β,TGF-β)等,其中FGF2可通过促进血管生成、肉芽形成,减少瘢痕形成,加速上皮化促进伤口愈合。FGF2半衰期短,在体内易受酶和皮肤微环境的影响,在伤口处保留时间短暂,降低了其促进伤口愈合的能力,因此,FGF2的稳定性对其临床用于皮肤损伤修复尤为重要。本文就FGF2的分子结构及功能、FGF2受体激活的信号转导途径、FGF2在伤口愈合方面的作用机制及其在整形方面的应用作一综述。     

重组人成纤维细胞生长因子21慢病毒质粒的构建及鉴定

目的构建人成纤维细胞生长因子21(human fibroblast growth factor 21,h FGF21)重组慢病毒质粒,并进行包装和鉴定。方法 PCR扩增人FGF21 ORF序列,经Eco RⅠ和Bam HⅠ双酶切后,连接至慢病毒载体PLV-EF1a-EGFP[2A]Puro,构建重组慢病毒质粒PLV-EF1a-EGFP[2A]Puro-h FGF21,经293T细胞包装为重组慢病毒颗粒,并感染KMB17靶细胞。荧光显微镜观察293T细胞中报告基因EGFP的绿色荧光,判断重组慢病毒的感染效率;RT-PCR法检测KMB17靶细胞中h FGF21基因m RNA的转录;免疫荧光和Western blot法检测KMB17靶细胞中h FGF21蛋白的表达。结果重组慢病毒质粒PLV-EF1a-EGFP[2A]Puro-h FGF21经双酶切及测序鉴定,证明构建正确,在包装细胞中获得较高的转染效率,重组慢病毒感染KMB17靶细胞72 h后,荧光显微镜下可见EGFP绿色荧光。感染组KMB17靶细胞中存在h FGF21基因m RNA的转录和蛋白的表达。结论成功构建了重组慢病毒质粒PLV-EF1aEGFP[2A]Puro-h FGF21,并于KMB17靶细胞中表达,为FGF21功能与特性的相关研究及基因工程药物的探索和研发奠定了基础。     

EDTA在重组Fc融合蛋白纯化工艺中的作用

为了研究EDTA在FGF21-L-Fc融合蛋白纯化工艺中的作用,将样品以是否添加EDTA及其添加方式分为3组,选用阴离子交换介质Q Sepharose Fast Flow和分子筛介质Superdex 200层析技术纯化了3组蛋白,使用非还原非变性SDS-PAGE、SEC-HPLC以及RP-HPLC分析和检测三组蛋白的纯度。研究发现,含EDTA缓冲液组、添加EDTA干粉组和无EDTA组的非还原非变性SDS-PAGE的纯度分别为99.61%、99.02%和98.90%;SEC-HPLC纯度分别为99.39%、99.00%和98.53%;RP-HPLC纯度分别为99.01%、98.83%和97.51%。结果表明,在FGF21-L-Fc融合蛋白纯化过程中添加EDTA在保持蛋白质稳定性的基础上能提高其纯度。     

重组F基因缺失型仙台病毒hFGF2基因治疗制剂质控方法及质量标准的建立

目的建立搭载2型人成纤维细胞生长因子(human fibroblast growth factor 2,h FGF2)重组F基因缺失型仙台病毒(Sendai virus,Se V)制剂(Se V-h FGF2/d F)的质控方法与质量标准。方法采用RT-PCR法对Se V载体中插入的目的基因h FGF2和缺失的F基因进行鉴别,同时扩增两个基因片段M-HN和h FGF2-NP,以鉴别该病毒;鸡红细胞凝集试验检测制品的血凝效价,并计算病毒颗粒数;免疫荧光法测定Se V-h FGF2/d F的感染滴度,结合病毒颗粒数计算其比滴度;Se V-h FGF2/d F体外感染COS7细胞后,ELISA法测定感染上清中h FGF2的表达量;将感染上清体外作用于BALB/c 3T3细胞,3T3细胞增殖法检测h FGF2的生物学活性;酚-氯仿法抽提样品的DNA,Pico-Green法测定制品中DNA残留量;PCR法检测腺病毒残留。结果重组Se V-h FGF2/d F基因组中h FGF2基因、F基因、M-HN片段和h FGF2-NP片段的RT-PCR鉴定结果与理论值相符;血凝效价为1∶512,病毒颗粒数为4.12×1010 VP/ml;感染滴度为2.06×109 CIU/ml,比滴度为5.0%;Se V-h FGF2/d F以MOI 10感染COS7细胞72 h后,ELISA检测上清中h FGF2的表达量为117.1 ng/ml;表达上清中h FGF2的生物学活性为437 IU/ml;DNA残留量为2.24 ng/ml;制品中腺病毒的PCR检测结果为阴性;其他各项指标均符合《人基因治疗研究和制剂质量控制技术指导原则》及《中国药典》三部(2010版)要求。结论初步建立了Se V-h FGF2/d F的质控方法和质量标准,为保证该制品的安全、有效、质量可控奠定了基础,同时也为其他Se V载体基因治疗药物的质量控制提供了参考。     

富自体浓缩生长因子生物学作用的研究进展

富自体浓缩生长因子(concentrated growth factor,CGF)为第三代血小板浓缩产物,是再生医疗领域中诱导组织再生分化的一种新型生物材料。CGF通过差速离心可释放出多种生长因子,如血小板衍生生长因子(plateletderived growth factor,PDGF)、转化生长因子-β(transforming growth factor-β,TGF-β)、类胰岛素生长因子(insulin-like growth factor,IGF)、血管内皮生长因子(vascular endothelial growth factor,VEGF)、表皮生长因子(epidermal growth fcator,EGF)及成纤维细胞生长因子(fibroblast growth factor,FGF)等,这些生长因子相互作用,可发挥促进组织再生的作用。本文就CGF在促进细胞增殖及分化、组织再生及修复、软组织愈合等生物学作用中的研究进展作一综述。     

短小芽孢杆菌β-1,4-葡聚糖内切酶基因的克隆及在大肠杆菌中的分泌表达

从一株产碱性纤维素酶的短小芽孢杆菌H12中克隆了编码β-1,4-葡聚糖内切酶的基因,对其基因序列及其酶的结构域进行了分析预测,同时将该酶的基因构建于大肠杆菌表达载体pET20b中,获得重组表达载体pET20b-EglA,将其转化至大肠杆菌BL21(DE3)菌株中进行表达。结果表明,该基因大小为1980 bp,共编码659个氨基酸;对β-1,4-葡聚糖内切酶结构域分析表明,该酶由两个不连续的结构域组成,其一为N-端催化结构域,由糖基水解酶家族9组成,其二为C-端底物结合结构域,由碳水化合物绑定结构域家族3组成;平板实验结果表明,β-1,4-葡聚糖内切酶基因在重组大肠杆菌中得到了良好的分泌表达;SDS-PAGE电泳图谱表明该酶的分子大小约为73 kDa。     

重组小鼠碱性成纤维细胞生长因子在CHO-K1-SFS细胞中的表达

目的构建小鼠碱性成纤维细胞生长因子(basic fibroblast growth factor,b FGF,亦称FGF-2)的真核表达质粒,并于无血清悬浮培养的CHO-K1-SFS细胞中进行表达。方法以小鼠垂体组织总RNA为模板,PCR扩增b FGF基因,并克隆至真核表达载体p EGFP-C1,构建重组表达质粒p EGFP-C1-b FGF,经Lipofectamine 2000介导转染无血清悬浮培养的CHO-K1-SFS细胞,荧光显微镜观察CHO-K1-SFS细胞中EGFP的表达情况,普通光学显微镜观察CHO-K1-SFS细胞的生长状况和细胞形态,RT-PCR法检测CHO-K1-SFS细胞中b FGF基因的转录,Western blot法检测CHOK1-SFS细胞中b FGF蛋白的表达。结果重组表达质粒p EGFP-C1-b FGF经双酶切(BglⅡ/SalⅠ)鉴定证明构建正确;重组质粒p EGFP-C1-b FGF转染后24、48、72及96 h的CHO-K1-SFS细胞均可见特异性绿色荧光蛋白表达,重组质粒p EGFP-C1-b FGF转染对CHO-K1-SFS细胞形态和增殖速率不产生影响;p EGFP-C1-b FGF转染组CHO-K1-SFS细胞可扩增出510 bp的目的条带;p EGFP-C1-b FGF转染组可见相对分子质量约44 000的特异性条带,表达产物可与兔抗b FGF多克隆抗体发生特异性结合。结论构建的真核表达质粒p EGFP-C1-b FGF在无血清悬浮培养的CHO-K1-SFS细胞中成功的表达,为进一步实现小鼠b FGF在哺乳动物细胞中的分泌表达及药物开发奠定了基础。     

大肠埃希菌对人结肠癌细胞RKO产生β防御素-3的影响

<正>β防御素是天然抗菌肽家族的重要成员,同时也是机体先天性防御屏障的重要组成部分,对细菌、真菌和病毒入侵机体具有重要的防御作用~[1-2]。β防御素-3通常受外界环境的刺激而产生~[3],在人体上皮细胞和黏膜组织中广泛表达,具有广谱的抗微生物活性,能促进伤口愈合,发挥免疫调节     

α-β-sialon FGM的制备研究

作为一种重要的结构陶瓷,sialon因其特有的物理、化学性能一直是该领域的研究热点。sialon家族的两个重要成员,α-sialon具有高硬度,β-sialon则具有高韧性。本课题研究了相容区域的α-sialon和β-sialon的烧结行为,微观结构,以此为基础制备了sialon基对称成分梯度陶瓷材料,研究了该材料的微观结构,并用有限单元法预测了残余应力。其数值远低于sialon的抗压强度和抗张强度,不会造成材料的断裂和失效。     

BRD7/9 bromodomains蛋白化学探针研究进展

Bromodomains(BRDs)结构域可以特异性识别乙酰化的组蛋白赖氨酸,这是表观遗传调控过程中的关键步骤。目前对BRDs家族的研究主要集中在BET家族,对其他家族少有涉及。最近,靶向于BRD7/9的化学小分子探针陆续被发现。本文通过对BRD7/9 bromodomains结构、BRD7/9小分子探针的研究历程及其构效关系等多方面进行总结,以期进一步探索BRD7/9的生物学功能和疾病治疗中的潜在用途,为设计和开发高活性的BRD7/9 bromodomains小分子抑制剂提供参考依据。     

The Same Metabolic Response to FGF21 Administration in Male and Female Obese Mice Is Accompanied by Sex-Specific Changes in Adipose Tissue Gene Expression

The preference for high-calorie foods depends on sex and contributes to obesity development. Fibroblast growth factor 21 (FGF21) beneficially affects taste preferences and obesity, but its action has mainly been studied in males. The aim of this study was to compare the effects of FGF21 on food preferences and glucose and lipid metabolism in C57Bl/6J male and female mice with diet-induced obesity. Mice were injected with FGF21 or vehicle for 7 days. Body weight, choice between standard (SD) and high-fat (HFD) diets, blood parameters, and gene expression in white (WAT) and brown (BAT) adipose tissues, liver, muscles, and the hypothalamus were assessed. Compared to males, females had a greater preference for HFD; less WAT; lower levels of cholesterol, glucose, and insulin; and higher expression of Fgf21, Insr, Ppara, Pgc1, Acca and Accb in the liver and Dio2 in BAT. FGF21 administration decreased adiposity; blood levels of cholesterol, glucose, and insulin; hypothalamic Agrp expression, increased SD intake, decreased HFD intake independently of sex, and increased WAT expression of Pparg, Lpl and Lipe only in females. Thus, FGF21 administration beneficially affected mice of both sexes despite obesity-associated sex differences in metabolic characteristics, and it induced female-specific activation of gene expression in WAT.     

Contribution of Yeast Studies to the Understanding of BCL-2 Family Intracellular Trafficking

BCL-2 family members are major regulators of apoptotic cell death in mammals. They form an intricate regulatory network that ultimately regulates the release of apoptogenic factors from mitochondria to the cytosol. The ectopic expression of mammalian BCL-2 family members in the yeast Saccharomyces cerevisiae, which lacks BCL-2 homologs, has been long established as a useful addition to the available models to study their function and regulation. In yeast, individual proteins can be studied independently from the whole interaction network, thus providing insight into the molecular mechanisms underlying their function in a living context. Furthermore, one can take advantage of the powerful tools available in yeast to probe intracellular trafficking processes such as mitochondrial sorting and interactions/exchanges between mitochondria and other compartments, such as the endoplasmic reticulum that are largely conserved between yeast and mammals. Yeast molecular genetics thus allows the investigation of the role of these processes on the dynamic equilibrium of BCL-2 family members between mitochondria and extramitochondrial compartments. Here we propose a model of dynamic regulation of BCL-2 family member localization, based on available evidence from ectopic expression in yeast.     

Leptin,Acting at Central Level,Increases FGF21 Expression in White Adipose Tissue via PPARβ/δ

The altered function of adipose tissue can result in obesity, insulin resistance, and its metabolic complications. Leptin, acting on the central nervous system, modifies the composition and function of adipose tissue. To date, the molecular changes that occur in epididymal white adipose tissue (eWAT) during chronic leptin treatment are not fully understood. Herein we aimed to address whether PPARβ/δ could mediate the metabolic actions induced by leptin in eWAT. To this end, male 3-month-old Wistar rats, infused intracerebroventricularly (icv) with leptin (0.2 μg/day) for 7 days, were daily co-treated intraperitoneally (ip) without or with the specific PPARβ/δ receptor antagonist GSK0660 (1 mg/kg/day). In parallel, we also administered GSK0660 to control rats fed ad libitum without leptin infusion. Leptin, acting at central level, prevented the starvation-induced increase in circulating levels of FGF21, while induced markedly the endogenous expression of FGF21 and browning markers of eWAT. Interestingly, GSK0660 abolished the anorectic effects induced by icv leptin leading to increased visceral fat mass and reduced browning capacity. In addition, the pharmacological inhibition of PPARβ/δ alters the immunomodulatory actions of central leptin on eWAT. In summary, our results demonstrate that PPARβ/δ is involved in the up-regulation of FGF21 expression induced by leptin in visceral adipose tissue.     

Chloride Channelopathies of ClC-2

Chloride channels (ClCs) have gained worldwide interest because of their molecular diversity, widespread distribution in mammalian tissues and organs, and their link to various human diseases. Nine different ClCs have been molecularly identified and functionally characterized in mammals. ClC-2 is one of nine mammalian members of the ClC family. It possesses unique biophysical characteristics, pharmacological properties, and molecular features that distinguish it from other ClC family members. ClC-2 has wide organ/tissue distribution and is ubiquitously expressed. Published studies consistently point to a high degree of conservation of ClC-2 function and regulation across various species from nematodes to humans over vast evolutionary time spans. ClC-2 has been intensively and extensively studied over the past two decades, leading to the accumulation of a plethora of information to advance our understanding of its pathophysiological functions; however, many controversies still exist. It is necessary to analyze the research findings, and integrate different views to have a better understanding of ClC-2. This review focuses on ClC-2 only, providing an analytical overview of the available literature. Nearly every aspect of ClC-2 is discussed in the review: molecular features, biophysical characteristics, pharmacological properties, cellular function, regulation of expression and function, and channelopathies.     

Fibroblast Growth Factor 21 Response in a Preclinical Alcohol Model of Acute-on-Chronic Liver Injury

Background and Aims: Fibroblast growth factor (FGF) 21 has recently been shown to play a potential role in bile acid metabolism. We aimed to investigate the FGF21 response in an ethanol-induced acute-on-chronic liver injury (ACLI) model in Abcb4^−/− mice with deficiency of the hepatobiliary phospholipid transporter. Methods: Total RNA was extracted from wild-type (WT, C57BL/6J) and Abcb4⁻/⁻ (KO) mice, which were either fed a control diet (WT-Cont and KO-Cont groups; n = 28/group) or ethanol diet, followed by an acute ethanol binge (WT-EtOH and KO-EtOH groups; n = 28/group). A total of 58 human subjects were recruited into the study, including patients with alcohol-associated liver disease (AALD; n = 31) and healthy controls (n = 27). The hepatic and ileal expressions of genes involved in bile acid metabolism, plasma FGF levels, and bile acid and its precursors 7α- and 27-hydroxycholesterol (7α- and 27-OHC) concentrations were determined. Primary mouse hepatocytes were isolated for cell culture experiments. Results: Alcohol feeding significantly induced plasma FGF21 and decreased hepatic Cyp7a1 levels. Hepatic expression levels of Fibroblast growth factor receptor 1 (Fgfr1), Fgfr4, Farnesoid X-activated receptor (Fxr), and Small heterodimer partner (Shp) and plasma FGF15/FGF19 levels did not differ with alcohol challenge. Exogenous FGF21 treatment suppressed Cyp7a1 in a dose-dependent manner in vitro. AALD patients showed markedly higher FGF21 and lower 7α-OHC plasma levels while FGF19 did not differ. Conclusions: The simultaneous upregulation of FGF21 and downregulation of Cyp7a1 expressions upon chronic plus binge alcohol feeding together with the invariant plasma FGF15 and hepatic Shp and Fxr levels suggest the presence of a direct regulatory mechanism of FGF21 on bile acid homeostasis through inhibition of CYP7A1 by an FGF15-independent pathway in this ACLI model. Lay Summary: Alcohol challenge results in the upregulation of FGF21 and repression of Cyp7a1 expressions while circulating FGF15 and hepatic Shp and Fxr levels remain constant both in healthy and pre-injured livers, suggesting the presence of an alternative FGF15-independent regulatory mechanism of FGF21 on bile acid homeostasis through the inhibition of Cyp7a1.     

Molecular Characterization of the Extracellular Domain of Human Junctional Adhesion Proteins

The junction adhesion molecule (JAM) family of proteins play central roles in the tight junction (TJ) structure and function. In contrast to claudins (CLDN) and occludin (OCLN), the other membrane proteins of the TJ, whose structure is that of a 4α-helix bundle, JAMs are members of the immunoglobulin superfamily. The JAM family is composed of four members: A, B, C and 4. The crystal structure of the extracellular domain of JAM-A continues to be used as a template to model the secondary and tertiary structure of the other members of the family. In this article, we have expressed the extracellular domains of JAMs fused with maltose-binding protein (MBP). This strategy enabled the work presented here, since JAM-B, JAM-C and JAM4 are more difficult targets due to their more hydrophobic nature. Our results indicate that each member of the JAM family has a unique tertiary structure in spite of having similar secondary structures. Surface plasmon resonance (SPR) revealed that heterotypic interactions among JAM family members can be greatly favored compared to homotypic interactions. We employ the well characterized epithelial cadherin (E-CAD) as a means to evaluate the adhesive properties of JAMs. We present strong evidence that suggests that homotypic or heterotypic interactions among JAMs are stronger than that of E-CADs.     

The Interplay between Mitochondrial Morphology and Myomitokines in Aging Sarcopenia

Sarcopenia is a chronic disease characterized by the progressive loss of skeletal muscle mass, force, and function during aging. It is an emerging public problem associated with poor quality of life, disability, frailty, and high mortality. A decline in mitochondria quality control pathways constitutes a major mechanism driving aging sarcopenia, causing abnormal organelle accumulation over a lifetime. The resulting mitochondrial dysfunction in sarcopenic muscles feedbacks systemically by releasing the myomitokines fibroblast growth factor 21 (FGF21) and growth and differentiation factor 15 (GDF15), influencing the whole-body homeostasis and dictating healthy or unhealthy aging. This review describes the principal pathways controlling mitochondrial quality, many of which are potential therapeutic targets against muscle aging, and the connection between mitochondrial dysfunction and the myomitokines FGF21 and GDF15 in the pathogenesis of aging sarcopenia.     

Evidence for a second conserved arginine residue in the integrase family of recombination proteins

This study was designed to search for new regions of similarityin the integrase family of recombination proteins which consistsof 28 members found in bacteria and yeast. A computer methodbased on an information content analysis has been used to alignlocal regions of homology in the set of unaligned protein sequencesfrom this family. Among the aligned regions with high informationcontent were those containing the known conserved histidine,arginine and tyrosine residues. In addition, a new region wasidentified containing another arginine residue that appearsto be conserved in all members of the family. To test furtherthe importance of this newly identified arginine residue, mutantsin the Cre protein from phage PI, a member of this integrasefamily, have been constructed which alter this residue. Themutations which change arginine to lysine and arginine to cysteinedepress catalytic activity but not site-specific binding tothe lox site. This result is expected for a conserved activesite residue. This computer analysis also provides a means forsearching for new members of the integrase family     

Analysis of heregulin symmetry by weighted evolutionary tracing

Heregulins are members of the protein family of EGF-like growthand differentiation factors. The primary cell-surface targetsof heregulins are heterodimers of the EGF-receptor homolog HER2with either HER3 or HER4. We used a weighted evolutionary traceanalysis to identify structural features that distinguish theEGF-like domain (hrg) of heregulins from other members of theEGF family. In this analysis, each amino acid sequence is weightedaccording to its uniqueness and the variability in each positionis assigned by an amino acid substitution matrix. Conservedresidues in heregulin that are variable in other EGF-like domainsare considered possible specificity-conferring residues. Thisanalysis identifies two clusters of residues at the foot ofthe boot-shaped hrg domain. The residues in one cluster arerecruited from the N-terminus; those in the other are from the-loop region and show a weak sequence similarity to the N-terminalresidues at the opposite side of the boot. The remaining residueswith high conservation scores distribute themselves into thesetwo distinct surfaces on hrg. This pseudo-twofold symmetry andthe presence of two distinct interfaces may reflect the preferenceof hrg for heterodimeric versus homodimeric HER complexes.