The origin and evolution of Basigin(BSG) gene: A comparative genomic and phylogenetic analysis

Basigin (BSG), also known as extracellular matrix metalloproteinase inducer (EMMPRIN) or cluster of differentiation 147 (CD147), plays various fundamental roles in the intercellular recognition involved in immunologic phenomena, differentiation, and development. In this study, we aimed to compare the similarities and differences of BSG among organisms and explore possible evolutionary relationships based on the comparison result. We used the extensive BLAST tool to search the metazoan genomes, N-glycosylation sites, the transmembrane region and other functional sites. We then identified BSG homologs from genomic sequences and analyzed their phylogenetic relationships. We identified that BSG genes exist not only in the vertebrate metazoans but also in the invertebrate metazoans such as Amphioxus B. floridae, D. melanogaster, A. mellifera, S. japonicum, C. gigas, and T. patagoniensis. After sequence analysis, we confirmed that only vertebrate metazoans and Cephalochordate (amphioxus B. floridae) have the classic structure (a signal peptide, two Ig-like domains (IgC2 and IgI), a transmembrane region, and an intracellular domain). The invertebrate metazoans (excluding amphioxus B. floridae) lack the N-terminal signal peptides and IgC2 domain. We then generated a phylogenetic tree, genome organization comparison, and chromosomal disposition analysis based on the biological information obtained from the NCBI and Ensembl databases. Finally, we established the possible evolutionary scenario of the BSG gene, which showed the restricted exon rearrangement that has occurred during evolution, forming the present-day BSG gene.     

Stimulation of the regrowth of MPP+-damaged dopaminergic fibers by the treatment of mesencephalic cultures with basigin

Summary. Basigin (Bsg) is a transmembrane glycoprotein belonging to the immunoglobulin superfamily and widely expressed in the central nervous system. To elucidate functional role of Bsg in the central nervous system, the effects of its glutathione-S-transferase (GST) fusion protein on the number and neurite outgrowth of cultured rat mesencephalic dopaminergic neurons were measured. The fusion protein was not able to promote the survival and neurite outgrowth of tyrosine hydroxylase (TH)-positive neurons under serum-free condition. However, the treatment of 1-methyl-4-phenylpyridinium (MPP⁺)-exposed cultures with the fusion protein resulted in stimulation of the regrowth of damaged TH-positive fibers. Basic fibroblast growth factor (bFGF) also stimulated the regrowth of neurites in damaged neurons. These results indicate that Bsg may play an important role in the regrowth of damaged dopaminergic fibers. Received May 9, 2001; accepted July 2, 2001     

皮肤鳞状细胞癌中Basigin/CD147表达与肿瘤进展的相关性

目的 探讨Basigin/CD147在皮肤鳞状细胞癌(鳞癌)进展中的作用及其机制.方法 运用免疫组化方法检测36例浸润和复发/转移情况不同的原发皮肤鳞状细胞癌标本中Basigin和基质金属蛋白酶(MMPs)的表达.运用免疫印迹和免疫荧光法观察Basigin在培养角质形成细胞和鳞状细胞癌细胞中的表达和定位.结果 有浸润和伴复发/转移的原发鳞癌肿瘤细胞中Basigin、MMP-1、MMP-2和MT1-MMP的表达显着增高.肿瘤细胞周围成纤维细胞中MMP-1、MMP-2和MT1-MMP的表达亦与原发鳞癌的复发/转移密切相关.肿瘤细胞膜上Basigin的表达与成纤维细胞中MMP-1、MMP-2、MMP-3和MT1-MMP的表达间显着相关.增高表达的Basigin主要分布于鳞癌细胞膜的微绒毛上.结论 鳞癌细胞膜上增高表达的Basigin/CD147可能与周围成纤维细胞作用,诱导其MMPs产生,并通过这一机制在鳞癌进展中发挥重要作用.     

SELDI-TOF analysis of glioblastoma cyst fluid is an approach for assessing cellular protein expression

Abstract

Objectives:

In about 10% of glioblastoma patients, preoperative MRI discloses the presence of tumor cysts. Whereas the impact of cystic appearance on prognosis has been discussed extensively, only little is known about the tumor cyst fluid. In this study, we tested the feasibility of the surface enhanced laser desorption ionization time of flight (SELDI-TOF) technique to detect cyst fluid proteins.

Methods:

Cyst fluid was collected from 21 glioblastoma patients for SELDI-TOF analysis and compared to control cerebrospinal fluids from 15 patients with spinal stenosis. Resulting protein peaks with significant differences between groups were further described, using the molecular weight in an internet search of protein databases and publications. Two potential cyst fluid proteins, basigin and ferritin light chain, were selected for immunohistological detection in the histologic slides of the patients, metallothionein (MT) served as negative control.

Results:

As supposed from the results of the SELDI-TOF analysis, basigin and ferritin were detected immunohistochemically in the cyst wall, whereas MT was more equally distributed between the cyst wall and the surrounding tumor tissue. Median survival time of the patients was 20 months (range 2 to 102 months) and correlated with age, but not with expression of the three proteins.

Discussion:

The SELDI-TOF approach reveals a number of proteins, potentially present in glioblastoma cyst fluid. Identification of these proteins in tumor cells may help understand the pathogenetic pathways and the prognostic value of cystic changes.     

Basigin mRNA在早期缺血心肌和非缺血心肌的表达变化

目的 探讨Basigin mRNA在早期心肌缺血大鼠模型缺血心肌(EIM)和非缺血心肌(NIM)中的表达及意义.方法 以β-actin为内对照,应用real-time PCR方法 检测0 min、15 min、30 min、60 min早期缺血心肌和非缺血心肌Basigin mRNA的表达情况.结果 EIM、NIM、假手术(S0)组心肌和非手术组心肌Basigin mRNA表达在0 min差异没有统计学意义(P＞0.05).EIM组在心肌缺血15 min、30 min和60 min较0 min时Basigin mRNA表达降低,差异有统计学意义(P＜0.001),NIM组和SO组在不同时间段之间差异无统计学意义(P＞0.05);EIM组和NIM组在30 min、60 min时Basigin mRNA表达的差异有统计学意义(P＜0.05).结论 Basigin在缺血30 min参与心肌的病理生理过程,Basigin在鉴定早期心肌缺血死亡的案例中有十分重要的法医学意义.     

Basigin的分子作用机制及其在眼部的生物学功能

Ｂａｓｉｇｉｎ是调节细胞活性、信号接收及免疫识别的重要分子,参与发育、微生物感染、炎症发生、营养及药物运输。Ｂａｓｉｇｉｎ的分子结构及其与分子伴侣间的同源或异源交互作用是其发挥广泛生物学功能的重要基础。Ｂａｓｉｇｉｎ与视网膜的成熟和功能发挥有重要关系,其在眼部的其他生物学功能也值得关注。本文就Ｂａｓｉｇｉｎ分子机制及眼部特异性表达的最新研究进展进行综述。     

中国汉族人群BSG基因SNPs发掘与连锁不平衡分析

目的：探讨健康中国汉族人群中basigin（BSG）基因的单核苷酸多态性（single nucleotide polymorphisms,SNPs）发生情况。方法：随机收集48例健康、无亲缘关系的中国汉族人外周血液并提取基因组DNA,设计引物对所有个体BSG基因的启动子区、外显子区和外显子内含子交界区的序列进行PCR扩增和正反向测序,通过判读测序峰图,明确SNPs的发生情况及其频率;通过Hardy-Weinberg平衡分析、单倍型推测和连锁不平衡分析,确定BSG基因位点的单倍型标~SNPs（haplotype tag SNPs,htSNPs）;中性理论检验查明该基因位点SNPs频率分布是否符合选择中性。结果：共发现19个SNPs,其中包括2个新发现的SNPs;所有SNPs位点基因型分布均符合Hardy-Weinberg平衡。该基因位点共推测出4种常见单倍型域,确定9个SNPs为htSNPs。中性理论检验结果提示健康中国汉族人群BSG基因的SNPs分布符合中性进化假说。结论：首次对中国健康汉族人群BSG基因的SNPs进行了发掘,确定了其9个单倍型标签SNPs,为在汉族人群中研究该基因的遗传多态性与疾病易感性或药物反应性个体差异奠定了基础。     

Extracellular matrix metalloproteinase inducer in interstitial pneumonias

Extracellular matrix metalloproteinase inducer (EMMPRIN), a glycosylated transmembrane protein that induces matrix metalloproteinases (MMPs), is minimally expressed in the normal adult lung. We previously reported that it is up-regulated in murine bleomycin-induced lung injury. In this study, we determined the expression of EMMPRIN and its association with MMP-2, MMP-7, and MMP-9 in interstitial pneumonias (IPs). We performed immunohistochemistry for EMMPRIN and MMPs on lung tissue from 22 subjects with various IPs. We did bronchoalveolar lavage (BAL) on 9 of these subjects and 13 others with IPs to measure the soluble EMMPRIN in BAL fluid. For comparison, immunohistochemistry or BAL was done on 14 subjects without IPs. The staining intensity for each protein was scored from 0 to 3 in various epithelial cell types. Soluble EMMPRIN in BAL fluid was measured by an enzyme-linked immunosorbent assay. Extracellular matrix metalloproteinase inducer was prominent in abnormal epithelial cells. It was more prominent in hyperplastic type II cells, compared with epithelium in alveolar bronchiolization. It was also elevated in BAL fluid from the subjects with IPs. Matrix metalloproteinases were expressed in cells expressing EMMPRIN, although the profile of MMPs varied among the different abnormal epithelial cell types with MMP-2 and MMP-7 in hyperplastic type II cells and MMP-7 and MMP-9 in cells showing squamous metaplasia and cells comprising bronchiolization. These results suggest a role of EMMPRIN in reepithelialization in IPs.     

Basigin/CD147参与马兜铃酸损伤人肾小管上皮细胞的体外实验

目的:探讨马兜铃酸(AA)对人肾小管上皮细胞损伤机制及细胞外基质金属蛋白酶诱导因子(Basigin/CD147)在损伤过程中发挥的作用。方法:不同浓度AA(10、20、40μg/ml)作用于人近端肾小管上皮细胞(HK-2)不同时间(24、48 h)后,MTT比色法检测细胞增殖变化;Basigin/CD147干扰质粒转染HK-2,选取AA最适浓度(20μg/ml),ELISA法检测不同时间段(24、48 h)细胞上清液中转化生长因子-β1(TGF-β1)含量;实时定量(Real-time)PCR法检测Basigin/CD147 mRNA表达;Western印迹检测Basigin/CD147、TGF-β1和α-平滑肌肌动蛋白(α-SMA)的蛋白表达。结果:AA 48 h组TGF-β1含量显著高于空白组(P0.05),siRNA+AA 48 h组TGF-β1低于48 h AA组(P0.05);AA48 h组Basigin/CD147 mRNA含量显著高于空白组(P0.05),siRNA+AA 48 h组Basigin/CD147 mRNA显著低于48 h AA组(P0.05);AA 48 h组Basigin/CD147、α-SMA、TGF-β1蛋白表达明显高于空白组(P0.05),siRNA+AA 48 h组Basigin/CD147、α-SMA、TGF-β1蛋白表达均显著低于48 h AA组(P0.01)。结论:Basigin/CD147参与介导AA所致HK-2细胞损伤过程,干扰Basigin/CD147表达可能抑制AA引起的细胞纤维化;Basigin/CD147蛋白表达调控异常可能是引起马兜铃酸肾病的重要发病机制之一。