The functional interaction between CD98 and CD147 in regulation of virus-induced cell fusion and osteoclast formation

Membrane fusion is an important event in the functioning of a living organism. Life starts as a sperm fuses with the membrane of an egg, leading to its fertilization. Membrane fusion is also required for myogenesis, osteogenesis and placenta formation. Multinucleated giant cells originating from monocytes-macrophages are associated with granulomatous lesions formed in response to foreign bodies, viruses, and bacteria. The CD4 molecule acts as a receptor for HIV. The major virus envelope glycoprotein, gp120, attaches to CD4 molecules expressed on the host cell surface. After binding to CD4 on the target cells, HIV is internalized via direct, pH-independent fusion of the viral and cell membranes. However, attachment of HIV to CD4 on the target cells is not sufficient for fusion. Interaction of gp160-expressing cells with neighboring cells bearing surface CD4 molecules is also required for syncytium formation. Syncytium formation and subsequent generalized cell fusion have been reported as potentially important mechanisms of virus-induced cytotoxic effects. Some antibodies against CD98/FRP-1 suppressed virus-induced cell fusion and CD98-mediated cell fusion of monocytes, indicating that CD98/FRP-1 molecules are able to regulate cell fusion. In this study, the functional interaction between CD98 and CD147 was investigated. Three kinds (Ab1, 2, and 3) of anti-CD147 and three kinds of anti-CD98 antibodies were used. Ab1 suppressed CD98-mediated cell fusion, but showed no effect on cell aggregation of Cd⁺U2ME-7 cells, U937–2 cells expressing HIV gp160. On the other hand, Ab2 enhanced the CD98-mediated cell fusion. Ab1 showed suppressive effect at early stage and Ab2 showed enhancing effect at later stage. Ab2 and 3 suppressed the spontaneous cell agglutination and cell fusion of Cd⁺JME-2 cells, Jurkat cells expressing HIV gp160. Ab2 suppressed CD98-mediated cell fusion, but showed no effect on cell aggregation of Cd⁺JME-2 cells. Ab2 cancelled suppression of cell fusion induced by suppressive antibody against CD98. Ab2 and 3 also suppressed CD98-mediated cell fusion of monocytes. This study indicates the functional interaction between CD98 and CD147 in the regulation of cell fusion.     

CD147对前列腺癌PC-3细胞自噬的影响

 目的：研究白细胞分化抗原（CD）147在体外对前列腺癌PC-3细胞的自噬作用。方法：通过氨基酸饥饿法建立自噬模型,免疫印迹技术检测CD147的表达。利用RNA干扰CD147表达的细胞系,免疫印迹技术检测自噬蛋白LC3-I和LC3-II的表达;台盼蓝排斥实验检测细胞的死亡情况。结果：在PC-3细胞自噬模型中,随着饥饿诱导时间延长,CD147表达逐渐升高。用RNA干扰技术降低CD147表达后,与阴性对照组比较,在自噬模型中CD147干扰组自噬相关蛋白LC3-II表达增多;并且细胞死亡数量明显增加,阴性对照组细胞死亡率分别为（19.3±3.1）%和（22.3±3.5）%,而在CD147干涉组细胞死亡率为(38.4±3.1)%,差异有统计学意义（P<0.05）。结论：在前列腺癌PC-3细胞中CD147抑制饥饿诱导的自噬,减少自噬性细胞死亡的发生。     

CD147分子通过VEGF促进类风湿关节炎滑膜组织中的血管新生

目的观察类风湿关节炎(RA)滑膜组织中CD147表达强度与血管内皮生长因子(VEGF)表达水平间的相关性,并探讨成纤维样滑膜细胞(FLS)表面CD147的水平变化对VEGF表达的影响。方法收集15例RA患者滑膜,以4例骨关节炎(OA)患者滑膜作对照,采用免疫组织化学SP染色方法检测滑膜组织中CD147和VEGF的表达;体外原代培养FLS细胞,分别加入CD147抗体,PI3K通路阻断剂,MAPK通路的ERK1/2、P38及JNK阻断剂等作用FLS细胞,ELISA检测细胞培养上清中VEGF的表达水平。结果与4例OA滑膜组织CD147和VEGF表达相比,15例RA滑膜组织中均有CD147、VEGF均高表达。其中,表达CD147的细胞主要为成纤维样滑膜细胞、单核-巨噬细胞和淋巴细胞;表达VEGF的细胞主要为成纤维样滑膜细胞、微血管周围成纤维样细胞及血管平滑肌细胞。滑膜组织中CD147和VEGF的表达强度间具有统计学意义。ELISA结果显示,在使用LY294002或抗HAb18GmAb阻断CD147表达后,VEGF的表达量显著下降(P<0.05);而MAPK阻断剂(PD98059、SP600125和SB203580)等对VEGF表达水平无统计学意义(P>0.05)。结论CD147经PI3K-Akt信号通路在RA滑膜组织中上调VEGF促进血管新生。提示CD147在RA血管新生和血管翳形成中有重要意义。     

Expression of CD 44 s, CD 44 v 3 and CD 44 v 6 in benign and malignant breast lesions: correlation and colocalization with hyaluronan

AIMS: To examine the expression of CD 44 s, CD 44 v 3 and CD 44 v 6 in breast lesions, and to correlate it with the expression of hyaluronan (HA). Methods and results: CD 44 expression was studied in 75 breast tissue samples, consisting of benign, premalignant and malignant breast lesions, using immunohistochemistry. CD 44 s, but not CD 44 v 3 or CD 44 v 6, was found in the stromal cells, and it was similar in benign and malignant tumours. In benign lesions CD 4 v 6 was detected in 20-30% of the ductal epithelial cells, while C 44 v 3 and CD 44 s were not expressed. CD 44 s, CD 44 v 3 and CD 44 v 6 were all up-regulated in the in situ carcinomas and invasive carcinomas. The level of CD 44 expression in carcinoma cells did not correlate with the type or differentiation of the tumours. CD 44 and HA expression levels were not closely linked in the benign or malignant breast lesions, because HA was overexpressed later in breast cancer progression than CD 44. However, in breast carcinomas CD 44 and HA positivity was often found in the same areas of the sections, and the dual staining confirmed actual colocalization of CD 44 s and HA in the same cells. Conclusions: CD 44 s, CD 44 v 3 and CD 44 v 6 are up-regulated earlier than HA in breast carcinoma progression, and in later stages they often colocalize with cell surface HA.     

Expression of CD44 and its variant isoform v3 has no prognostic value in gastric cancer

AIMS: To study the controversial role of transmembrane glycoprotein CD44 as a moderator of tumour spread and as a prognostic factor in gastric cancer. METHODS and RESULTS: The expression of all CD44 forms and that with exon v3 was assessed in 198 stage I-IV gastric adenocarcinomas using immunohistochemistry. CD44 expression was found in 72% and CD44v3 in 55% of the cases. The intensity of CD44 expression was associated with the level of invasion and with hyaluronan expression, while the frequency of CD44 positive cells was not significantly related to any of the clinical or histological features of the tumours. CD44v3 expression failed to show any association with the clinical or histological variables examined. Neither total CD44 nor CD44v3 expression affected survival. The most important prognostic factors in this cohort were the level of invasion, lymph node status, tumour size and vascular or perineural invasion. CONCLUSIONS: Changes in CD44 or CD44v3 expression level do not predict tumour spread or patient survival in gastric cancer.     

子宫颈癌中CD147蛋白和MMP-9 mRNA的表达及意义

目的 探讨CD147蛋白、MMP-9 mRNA在子宫颈鳞状细胞癌中的表达及其与侵袭、转移的关系.方法 采用免疫组化MaxVision法、RT-PCR技术检测10例慢性子宫颈炎组织(对照组)和40例子宫颈鳞状细胞癌患者的外科手术切除标本组织中CD147蛋白、MMP-9 mRNA的表达,应用图像分析软件分别对CD147和MMP-9 mRNA的表达进行平均光密度和灰度分析.结果 CD147蛋白和MMP-9 mRNA的表达结果显示:子宫颈鳞状细胞癌组高于对照组慢性子宫颈炎组织(P值均＜0.01);有淋巴转移组高于无转移组(P＜0.01、P＜0.05);CD147蛋白在宫颈鳞状细胞癌低分化组表达与中分化组表达差异无显著性(P＞0.05),但MMP-9 mRNA表达为低分化组高于中分化组(P＜0.05).结论 CD147蛋白和MMP-9 mRNA在子宫颈鳞状细胞癌中呈高表达,它们之间的表达具有正相关性,二者可能共同参与了子宫颈鳞状细胞癌的侵袭和转移过程.     

CD147蛋白和MMP-9在子宫腺肌病中的表达和意义

目的:研究CD147蛋白、MMP-9在子宫腺肌病患者组织中的表达及血清中可溶性CD147(sCD147)蛋白水平,探讨其在子宫腺肌病中的作用机制。方法:采用免疫组织化学SP法检测37例子宫腺肌病患者(子宫腺肌病组)子宫异位内膜、在位内膜及20例子宫肌瘤患者(对照组)子宫内膜组织中CD147蛋白和MMP-9的表达,并对其蛋白表达量进行相关性分析;采用ELISA双抗体夹心法检测37例子宫腺肌病患者血清sCD147蛋白的水平,20例子宫肌瘤患者和20例女性健康体检者设为对照。结果:子宫腺肌病组异位与在位子宫内膜组织腺上皮细胞、间质细胞均有CD147蛋白、MMP-9表达,且明显高于对照组(P<0.01),其中异位内膜CD147蛋白、MMP-9表达量高于在位内膜(P<0.01);子宫腺肌病组CD147蛋白与MMP-9的表达量成正相关,对照组两者则无相关性。子宫腺肌病组血清sCD147蛋白的水平高于子宫肌瘤组(P>0.05)和健康体检者组(P<0.05)。结论:子宫腺肌病患者异位与在位内膜组织中CD147蛋白和MMP-9高表达及血清sCD147蛋白高水平可能与子宫腺肌病发生发展有关,且CD147蛋白可能通过促进MMP-9合成与分泌而发挥其作用。     

CD147 and CD98 complex-mediated homotypic aggregation attenuates the CypA-induced chemotactic effect on Jurkat T cells

Homotypic cell aggregation plays important roles in physiological and pathological processes, including embryogenesis, immune responses, angiogenesis, tumor cell invasion and metastasis. CD147 has been implicated in most of these phenomena, and it was identified as a T cell activation-associated antigen due to its obvious up-regulation in activated T cells. However, the explicit function and mechanism of CD147 in T cells have not been fully elucidated. In this study, large and compact aggregates were observed in Jurkat T cells after treatment with the specific CD147 monoclonal antibody HAb18 or after the expression of CD147 was silenced by RNA interference, which indicated an inhibitory effect of CD147 in T cell homotypic aggregation. Knocking down CD147 expression resulted in a significant decrease in CD98, along with prominent cell aggregation, similar to that treated by CD98 and CD147 monoclonal antibodies. Furthermore, decreased cell chemotactic activity was observed following CD147- and CD98-mediated cell aggregation, and increased aggregation was correlated with a decrease in the chemotactic ability of the Jurkat T cells, suggesting that CD147- and CD98-mediated homotypic cell aggregation plays a negative role in T cell chemotaxis. Our data also showed that p-ERK, p-ZAP70, p-CD3ζ and p-LCK were significantly decreased in the CD147- and CD98-knocked down Jurkat T cells, which suggested that decreased CD147- and/or CD98-induced homotypic T cell aggregation and aggregation-inhibited chemotaxis might be associated with these signaling pathways. A role for CD147 in cell aggregation and chemotaxis was further indicated in primary CD4⁺ T cells. Similarly, low expression of CD147 in primary T cells induced prominent cell aggregation and this aggregation attenuated primary T cell chemotactic ability in response to CypA. Our results have demonstrated the correlation between homotypic cell aggregation and the chemotactic response of T cells to CypA, and these data indicate that CD147 and CD98 might play important roles in cyclophilin-induced cell migration.     

The roles of CyPA and CD147 in cardiac remodelling

Cyclophilin A (CyPA), an abundantly expressed protein belonging to the immunophilin family, is involved in a variety of physiological and pathological activities together with its extracellular receptor, CD147. Many studies have provided compelling evidence supporting critical roles of CyPA in immune and infectious diseases and malignant tumours. Recent studies have revealed that both CyPA and CD147 strongly promote cardiovascular inflammation, myocardial ischaemia-reperfusion injury, and myocardial remodelling processes. Here, we review the potential roles of CyPA and CD147 in cardiac remodelling and their implications for the development of novel pharmacological therapies for heart failure.     

中性粒细胞增强类风湿关节炎滑膜细胞产生基质金属蛋白酶及其细胞侵袭力

目的：研究中性粒细胞表面CD147分子对类风湿关节炎（RA）成纤维样滑膜细胞（FLS）产生基质金属蛋白酶（MMP）及细胞侵袭力的作用。方法：取自关节镜或骨科手术治疗的RA、骨关节炎（OA）患者的滑膜组织，体外分离培养FLS，通过流式细胞术（FCM）检测细胞表面分子及形态学方法鉴定。采用全反式维甲酸（ATRA）诱导HL-60细胞（人早幼粒白血病细胞株）诱导中性粒细胞分化，并用硝基蓝四氮唑（NBT）还原反应测定其分化程度。进而以FCM测定分化前后的HL-60细胞及FLS表面CD147的表达，并通过明胶酶谱和重组基质侵袭实验检测分化前后HL-60细胞对FLS MMP表达和细胞侵袭能力的作用以及CD147拮抗肽（AP-9）对这种MMP表达和细胞侵袭能力的抑制作用。结果：成功建立了FLS分离培养和HL-60细胞分化的实验体系。培养的FLS具有典型成纤维细胞的形态，均一的高度表达CD90（〉98％）而不表达CD14。分化后的HL-60细胞CD147表达上调，RAFLS细胞CD147表达水平低于分化前及分化后HL-60细胞（P〈0．05）。明胶酶谱试验显示：①与OAFLS相比，单培养的RAFLS表达较高水平的酶原及活化形式的MMP-2（P〈0．05）；②分化前／后的HL-60细胞分别与FLS共培养，酶原及活化形式的MMP-2和MMP-9的表达水平较这些细胞单独培养均显著升高（P〈0．05），且分化后的HL-60细胞与FLS共培养酶原及活化形式MMP-2表达水平较分化前HL-60细胞与FLS共培养明显升高（P〈0．05）；③AP-9显著抑制两共培养组中MMP-2和MMP-9的上调作用（P〈0．05）。侵袭实验显示：RAFLS侵袭能力高于OA FLS（P〈0．05）；分化前后的HL-60均可增加RAFLS的侵袭能力（P〈0．05），且分化后强于分化前（P〈0．05）；AP-9可抑制这一促进作用，降低FLS的侵袭能力（P〈0．05）。结论：中性粒细胞可能通过CD147促进RA患者滑膜FLS MMP-2、MMP-9的表达和活化，增强FLS的侵袭能力，这种促进作用可被CD147拈抗肽所抑制，将为RA关节软骨和骨损伤机制和治疗的进一步研究提供了重要的线索。     

PMA对THP-1细胞和RA患者单核细胞及培养上清中CD147表达的影响

目的：研究豆蔻佛波醇乙酯（PMA）刺激前后,体外培养的人单核细胞系THP-1细胞和类风湿关节炎（RA）患者外周血单核细胞（human peripheral blood monocytes,HPBM）上及培养上清中CD147的表达.方法：以贴壁法分离RA患者HPBM.用PMA刺激体外培养的RA患者HPBM和THP-1细胞,采用流式细胞术动态检测THP-1细胞、RA患者HPBM膜表面CD147的表达.用双抗体夹心ELISA法检测培养上清中CD147分子的含量.结果：PMA刺激前,THP-1细胞膜及RA患者HPBM表面CD147分子的表达均较高,培养上清中均可检测到CD147分子.PMA刺激后,THP-1细胞培养上清中CD147的含量升高,THP-1细胞上CD147的表达先升高后降低,最后进入稳定期;RA患者的HPBM上CD147的表达下降,培养上清中CD147的含量升高,于刺激后2 d进入稳定期.结论：THP-1细胞、RA患者HPBM膜表面CD147分子可从细胞上脱落或由细胞直接分泌到培养液中.PMA可上调可溶性CD147的表达.     

CD44与乳腺癌的研究进展

CD44基因蛋白是一种细胞表面跨膜糖蛋白,属于黏附分子家族。CD44基因外显子根据表达方式可分为标准型CD44(CD44s)和变异型CD44(CD44v)两种类型。大量研究发现,CD44蛋白参与细胞-细胞、细胞-胞外基质之间的特异性粘附,CD44及其亚型在乳腺癌的异常表达可能与癌症的发生、发展和转移密切相关。此外,乳腺癌干细胞表面高度表达CD44分子,针对CD44分子与乳腺癌干细胞关系的研究,将会为临床上对乳腺癌的诊断、治疗选择以及预后预测提供更充分的理论依据。     

Effects of hyaluronan on the invasive properties of human breast cancer cells in vitro

Hyaluronan (HA) is a high molecular weight glycosaminoglycan present mostly in the extracellular matrix (ECM). HA binds to specific receptors such as CD44. Its production is increased at the tumour-stroma interface, including those in breast cancer tumours. It has been suggested that it facilitates invasion of tumour cells into the ECM by a hydrodynamic effect, or by altering tumour cell behaviour. Using in vitro tests we studied the effect of immobilized (iHA) and soluble (sHA) HA on the invasive properties of four human breast cancer cell lines with different levels of CD44 expression. Our results show that iHA acts as an adhesive, haptotactic, and motility stimulating factor for the CD44 positive Hs578T cells and induces the expression of membrane CD44. sHA also changes the motility properties of the Hs578T and MDA-231 cells and increases their CD44 expression. sHA or iHA have no measurable effect on the adhesion, motility or CD44 expression of the ZR-75-1 and MCF-7 breast cancer cells. Our results establish that in high CD44 expressing breast cancer cells HA modulates tumour cell adhesion and motility and also increases the expression of its own receptor, CD44.     

Elevated expression of hyaluronan and its CD44 receptor in the duodenal mucosa of coeliac patients

AIMS: Since hyaluronan (HA) metabolism is disturbed in some malignant tumours and in inflammatory diseases, we analysed HA and its receptor CD44 as well as the expression of the Ki67 nuclear protein, a marker of cell proliferation, in histological sections of duodenal biopsies of coeliac disease patients and controls. METHODS AND RESULTS: The study group consisted of 52 patients with coeliac disease in remission, 40 patients with newly diagnosed disease and 10 healthy control subjects. HA was detected with a specific biotinylated probe prepared from cartilage aggrecan and link protein, and CD44 with an antibody recognizing all forms of CD44 and another specific for its v6 variant. For the expression of the nuclear protein, monoclonal antibody MIB-1 was used. The percentage of HA-positive cells in surface epithelium was higher in newly diagnosed patients (13%) compared with patients in remission (11%) and controls (2%). In addition, HA intensity in the lamina propria was decreased in the newly diagnosed patients. In patients with active disease, 22-26% of the surface epithelium was CD44+, whereas the corresponding figure in patients in remission was 5%, and that of controls 1%. The more intensive MIB-1 labelling in the duodenal epithelium of coeliac patients without treatment was normalized after gluten-free diet. CONCLUSIONS: The HA-positive coat on surface epithelium seen even in patients in remission suggests persistent or even permanent changes in the epithelial permeability barrier in coeliac disease.     

Monocarboxylate Transporters 1 and 4 Are Associated with CD147 in Cervical Carcinoma

Due to the highly glycolytic metabolism of solid tumours, there is an increased acid production, however, cells are able to maintain physiological pH through plasma membrane efflux of the accumulating protons. Acid efflux through MCTs (monocarboxylate transporters) constitutes one of the most important mechanisms involved in tumour intracellular pH maintenance. Still, the molecular mechanisms underlying the regulation of these proteins are not fully understood. We aimed to evaluate the association between CD147 (MCT1 and MCT4 chaperone) and MCT expression in cervical cancer lesions and the clinico-pathological significance of CD147 expression, alone and in combination with MCTs. The series included 83 biopsy samples of precursor lesions and surgical specimens of 126 invasive carcinomas. Analysis of CD147 expression was performed by immunohistochemistry. CD147 expression was higher in squamous and adenocarcinoma tissues than in the non-neoplastic counterparts and, importantly, both MCT1 and MCT4 were more frequently expressed in CD147 positive cases. Additionally, co-expression of CD147 with MCT1 was associated with lymph-node and/or distant metastases in adenocarcinomas. Our results show a close association between CD147 and MCT1 and MCT4 expressions in human cervical cancer and provided evidence for a prognostic value of CD147 and MCT1 co-expression.     

CD147 modulates the differentiation of T‐helper 17 cells in patients with rheumatoid arthritis

The role of CD147 in regulation of rheumatoid arthritis (RA) is not fully elucidated. The aim of this study was to investigate the effect of cell‐to‐cell contact of activated CD14⁺ monocytes with CD4⁺ T cells, and the modulatory role of CD147 on T‐helper 17 (Th17) cells differentiation in patients with RA. Twenty confirmed active RA patients and twenty normal controls were enrolled. CD4⁺ T cells and CD14⁺ monocytes were purified by magnetic beads cell sorting. Cells were cultured under different conditions in CD4⁺ T cells alone, direct cell‐to‐cell contact co‐culture of CD4⁺ and CD14⁺ cells, or indirect transwell co‐culture of CD4⁺/CD14⁺ cells in response to LPS and anti‐CD3 stimulation with or without anti‐CD147 antibody pretreatments. The proportion of IL‐17‐producing CD4⁺ T cells (defined as Th17 cells) was determined by flow cytometry. The levels of interleukin (IL)‐17, IL‐6, and IL‐1β in the supernatants of cultured cells were measured by ELISA. The optimal condition for in vitro induction of Th17 cells differentiation was co‐stimulation with 0.1 μg/mL of LPS and 100 ng/mL of anti‐CD3 for 3 days under direct cell‐to‐cell contact co‐culture of CD4⁺ and CD14⁺ cells. Anti‐CD147 antibody reduced the proportion of Th17 cells, and also inhibited the productions of IL‐17, IL‐6, and IL‐1β in PBMC culture from RA patients. The current results revealed that Th17 differentiation required cell‐to‐cell contact with activated monocytes. CD147 promoted the differentiation of Th17 cells by regulation of cytokine production, which provided the evidence for pathogenesis and potential therapeutic targets for RA.     

CD147 shRNA质粒表达载体的构建及鉴定

目的构建表达细胞外基质金属蛋白酶诱导因子(CD147,EMMPRIN)基因序列特异性的短发夹样RNA(short hairpin RNA,shRNA)载体。方法根据CD147基因序列及shRNA设计原则,化学合成两段编码短发夹RNA寡核苷酸序列,将其定向克隆到pGenesil-1.1质粒表达载体中,重组构建RNAi质粒,并对重组质粒进行酶切分析。结果限制性内切酶Eco31I和SacI酶切显示设计合成的shRNA编码序列被成功插入pGenesil-1.1质粒载体中,酶切结果证实插入片段与设计序列完全一致,成功构建针对基因CD147的shRNA质粒表达载体。结论成功构建人CD147基因重组载体,为研究CD147蛋白的生物学效应和骨肉瘤的治疗提供实验依据。