Ischemia reperfusion-induced proteomic changes in rat skeletal muscle

AIM: To investigate ischemia reperfusion (I/R)-induced proteomic changes in rat skeletal muscle. METHODS: Healthy male Wistar rats were randomly divided into two groups as follows (n=6): sham group and I/R group. I/R of right hind limb was induced by 4 h ischemia followed by 24 h reperfusion. The 2-DE was applied to separate the proteins extracted from skeletal muscle tissue at the end of experiment, followed by Coomassie Brillant blue R-250 staining. Computer image analysis was used to determine the differential expression of proteins between the two groups, and 7 protein spots expressed differentially were picked out and subjected to in-gel digest and MALDI-TOP for identification. RESULTS: 354±13 proteins were detected and the match rate was (78.7±1.4)%. 10 proteins displayed significant changes after I/R, of which, 6 proteins increased and 3 proteins decreased in expression. Moreover, 2 spots in I/R group were observed, only 1 spots of which in control. 5 proteins were identified after mass spectrometry. Mitochondrial aldehyde dehydrogenase (ALDH) precursor, heat shock 27 kD protein (HSP27), an unnamed protein product (increased in I/R group), α-actin (decreased in I/R group), and nuclear transport factor 2 (NTF-2) W7a mutant were found in I/R group. CONCLUSION: I/R injury induced differential proteomic changes in rat skeletal muscle. ALDH, α-actin and HSP27 expression, and NTF-2 mutation are involved in I/R injury.     

Identification of proteins involved in insulin stimulation in v ascular smooth muscle cells of SHR rats

AIM:To identify proteins involved in insul in stimulation and the molecular mechanism of proliferation and migration in vas cular smooth muscle cells (VSMCs).METHODS:A series of methods,including 2-D electrophoresis,PDQ uest software analysis of 2-DE gels,peptide mass fingerprinting based on matrix -assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TO F-MS) and SWISS-PROT database searching,were used to separate and identify the differentially expressed proteins.The difference of some proteins was proved by Western blotting.Proliferation and migration of VSMCs treated with insulin wer e also observed.RESULTS:DNA synthesis were increased in VSMCs.［3H］-thymidi ne incorporation in VSMCs from SHR (14.40±0.85) was higher than that in VSMCs from WKY (9.21±0.93,P<0.05).Migration rate of VSMCs from SHR was abou t 1.8 times higher than that in VSMCs from WKY (P<0.05).Image analysis re vealed that averages of protein spots detected were 502±32 and 612±39 in contr ol VSMCs and in cells treated with insulin,respectively.Result of western blo tting confirmed that α-SM protein was down-regulated and matrix Gla,OPN protei ns were up-regulated by insulin stimulation.CONCLUSION:The results suggest that the differential proteomic analysis may be useful to study related proteins involved in insulin-regulated p roliferation in VSMCs.     

The proteome research of human lens epithelial cells by two-dimensional gel electrophoresis and mass spectrometry

AIM: To establish the techniques in the proteome research of human lens epithelial cells,including the techniques of two-dimensional electrophoresis and mass spectrometry.METHODS: Total protein of cultured human lens epithelial cells was extracted with two kinds of different methods.The proteins were separated using immobilized pH gradients 2-DE and visualized by silver staining.The digitized images obtained by GS-800 scaner were then analyzed with PDQuest software in order to establish the differential expression profiles.The differential expressed protein spots were cut from the gels using proteomework spot cutter and subjected to in-gel digestion with trypsin.The digested peptide separation was conducted by a Finnigan LCQ MS coupled with a Surveyor HPLC system. RESULTS: A high resolution and reproducible 2-ED image was successfully obtained.The maps of 2-DE showed that lens proteins were in the section of pH 4-7 which the relative molecular weight was 17-72 kD.Relative molecular weight of more abundant proteins was localized at 19-50 kD,as well as the isoelectric points were found to lie between PI 5-7.Two of these proteins were identified by mass spectrometry and database queries.CONCLUSION: A stable protein maps of human lens epithelial cells is constructed.The technique will be used in human lens research to characterize physiological processes and diseases.     

Effect of crystallin βB2 on the aging of lens

AIM: To study the effect of crystallin βB₂ on the aging of lens. METHODS: SD rats were maintained routinely and killed at 6 different ages (1 d, 8 d, 2 weeks, 8 weeks, 8 months and 1.5 years). Water-soluble crystallins were extracted and separated by two-dimensional polyacrylamide gel electrophoresis (IEF/SDS-PAGE). After Comassize blue staining, the crystallin patterns were screened and analyzed. βB₂ crystallin and the main chaperone proteins (αA₂, αB₂) were identified and the relative quantity was measured. RESULTS: (1) The quantity of water-soluble crystalline βB₂ increased in close relation to the aging of the rat. (2) αA₂, αB₂ chaperone proteins increased with the aging of the rat too. (3) The change of the quantity of water-soluble crystalline βB₂ was closely related to the changes of αA₂ , αB₂ chaperone proteins. (4) Degraded and modified crystallins began to appear clearly in the lens after 8 months old. CONCLUSION: Based on our results, we infer that water-soluble crystalline βB₂ increases with the aging dof the rat, which is helpful to maintain the structure and transparency of the lens.     

橡胶树死皮病黄色体差异表达蛋白的初步分析

橡胶树"死皮病"给橡胶种植业带来严重的危害.为了更好地了解和阐明死皮病发生、发展的分子机制,研究应用双向凝胶电泳技术(two-dimensional gel electrophshiya/oresis,2-DE)比较橡胶树死皮株与健康株胶乳黄色体蛋白质组表达的差异.采用TCA/丙酮沉淀法提取橡胶树死皮株与健康株黄色体蛋白质并采用固相pH梯度(immobjlized pH graalient,IPG)双向凝胶电泳分离两种材料蛋白质,凝胶经银染显色后,用PDQuest图像分析软件进行比较分析、识别差异表达的蛋白质.成功获得橡胶树死皮株与健康株胶乳黄色体的双向凝胶电泳图谱.鉴定出13个蛋白差异点,其中10个上调表达,3个下调表达.并应用质谱技术鉴定了其中部分表达差异的蛋白质点,对渗调蛋白进行功能分析,认为渗调蛋白在死皮株中表现下调的情形可能与死皮病的发生有一定的关系.     

淀粉酶家族基因在金针菇子实体不同发育时期的表达与分析

为分析淀粉酶对金针菇(Flammulina velutipes)子实体发育的作用,针对已经鉴定的金针菇淀粉酶家族基因(6个α-淀粉酶和1个γ-淀粉酶),采用定量PCR方法对其在不同发育时期(从原基形成第1天到第12天成熟开伞期)、不同组织部位(菌盖和菌柄)的表达量进行测定,进而分析其表达模式。结果显示:7个淀粉酶基因在菌柄中表达量均高于菌盖;其中,α-Amy-5和γ-Amy-1在菌柄中的表达量变化为先下调再上调,两个基因预测编码蛋白均有信号肽,亚细胞定位在细胞外,推测其可能参与菌柄细胞壁的形态建成;α-Amy-3亚细胞定位在线粒体中,与其它各发育时期相比,其在菌柄快速伸长期表达量达到最高。α-Amy-1和α-Amy-6基因则在金针菇成熟期表达量最高,推测其可能与金针菇菌盖的发育有关。     

Primary screening of stress protective proteins in heat-preconditioned fibroblast NIH-3T3

AIM：To establish stress adaptation model of mouse fibroblast cell line NIH-3T3 to analyze the effect of stress and adaptation on protein synthesis,and to screen for stress adaptation related proteins.METHODS：A stress-adapted cell model was established by thermal preconditioning (42 ℃,20 min).Total cytolytes were separated by 2-DE,analyzed by PDQUEST software,and the selected differential expression spots were detected by MOLDI-TOF.The effect of stress and adaptation on protein synthesis was studied.The stress adaptation related spots were identified by PMF.RESULTS：Comparative proteomics method by 2-DE was used to find different distributions of total proteins of heat stress group and thermal preconditioning group.Expression-increased protein spots were found almost limited in low molecular weight range in directly stress group,whereas expression-increased protein spots in thermal preconditioning group have more extensive molecular weight distribution.PMF results showed that tubulinβ,vimentin,eIF-4AI,Eno1 protein might be related to stress adaptation.CONCLUSION：2-DE analysis suggested,cell might favor to synthesize low small molecular weight protein to deal with hostile stress.Cellular protein storage might be increased by preconditioning,and may play a protection role during successive stress.The increased expression of tubulinβ，vimentin,eIF-4AI,Eno1 protein suggests that cytoskeletons,protein synthesis pathway and glycometabolism pathway may play an important role in stress adaption.     

Chemical compositions and insecticidal effects of essential oils isolated from Achillea gypsicola, Satureja hortensis, Origanum acutidens and Hypericum scabrum against broadbean weevil (Bruchus dentipes)

The essential oils of aerial parts of Achillea gypsicola Hub.-Mor., Hypericum scabrum L., Satureja hortensis L., and Origanum acutidens (Hand.-Mazz.) Letswaart were analyzed in this study by GC and GC–MS and their oils were tested for toxicity against broadbean weevil (Bruchus dentipes). A. gypsicola oil contained camphor (40.17%), 1,8-cineole (22.01%), piperitone (11.29%), borneol (9.50%) and α-terpineol (1.56%) as major components. A total of 74 components were identified by GC–MS in H. scabrum oil, including α-pinene (9.26%), terpinen-4-ol (5.12%), camphor (5.94%), δ-cadinene (4.52%), pulegone (4.45%), γ-muurolene (4.12%), pinocarvone (3.97%) and β-caryophyllene (3.42%) as predominant components. The essential oils of O. acutidens and S. hortensis were characterized by high contents of carvacrol (86.99% and 55.74%), γ-terpinene (0.71% and 20.94%), p-cymene (1.95% and 12.30%), α-terpinene (0.13% and 2.04%) and β-caryophyllene (1.30% and 1.08%). All of the essential oils were toxic to adults of B. dentipes and insect mortality increased with increasing concentration of each oil. The oils (20 μl dose) brought about 100% mortality in 36 h. Although desirable insecticidal activities against the pest were achieved with the oils from all four plant species, S. hortensis and O. acutidens oils were more effective, particularly after 6 h of treatment. The current results concluded that the essential oils, in particular O. acutidens and S. hortensis oils, may be used as potential botanical insecticides against B. dentipes.     

Differential proteomic analysis of liver in apoE/LDLR double-gene mutant mice

AIM: To comparatively study the differential expression of protein profiles of liver between double lipid metabolism genes mutant (apoE-/-/LDLR-/-) and wild type（WT）mice.The key proteins related to atherosclerosis and dysfunction of lipid metabolism were also characterized.METHODS: Two-dimensional gel electrophoresis and mass spectrometry were used to analyze the differential displayed proteomics of 5-week-old double-gene mutants and wild type mice fed a regular chow for 2 weeks.RESULTS: Approximately (928±15) spots and (1 017±50) spots were detected in apoE-/-/LDLR-/- mice (n=3) and WT mice livers (n=3),respectively.The average matched ratio was 78.7% and 83.2%.The differential expression analysis showed that the matched spots between apoE-/-/LDLR-/- mice and WT mice existed.Compared with the wild type,108 spots were not matched in apoE-/-/LDLR-/- mice.10 over expression spots (>5 fold) and 45 lower expression spots (>5 fold) were noted.Six significant differential proteins in gel were identified by LTQ-ESI,e.g.endoplasmin precursor,acidic leucin-rich nuclear phosphoprotein 32 family member A,serotransferrin precursor,stress-70 protein precursor,fibronectin precursor,complement C3 precursor,fibrinogen gamma polypeptide.CONCLUSION: The protein profile of apoE-/-/LDLR-/- mouse liver exhibits significant difference compared to that of WT mice.The results imply that lipid metabolism relative polygenetic mutation contributes to the alteration of mouse liver protein expression profile,especially that lipid metabolism related perhaps participates in dysfunction in lipid metabolism during atherogenesis.     

葡萄着色期果皮蛋白质组分析

为了研究葡萄不同着色期果皮中蛋白质表达特征,以着色初期、中期和后期等3个着色时期的葡萄果皮为研究对象,运用2-DE、MALDI-TOF/TOF-MS质谱技术以及生物信息学方法对差异蛋白进行分析,结果表明:(1)双向凝胶电泳显示,果皮着色3个时期有1050个高度重复的蛋白点,差异显著的蛋白点有162个,其中108个蛋白得到鉴定,有87个蛋白映射到葡萄蛋白质组数据库中;3个时期均表达的差异蛋白有20个,且随着果皮颜色加深,差异蛋白数量呈上升趋势。(2)GO分析显示,ATP合成酶β亚基(ATPβ)极显著富集于磷酸核糖代谢过程,对着色初期果皮生理代谢的能量需求具有重要意义。(3)KEGG分析表明,碳代谢、生物固碳、磷酸戊糖、氨基酸生物合成等代谢通路在果皮着色的不同时期显著富集。(4)qRT-PCR分析显示,S–腺苷甲硫氨酸合成酶基因(VvMETK4)在果皮着色后期表达量最高。     

26S proteasome regulates differentiation of human bone marrow stromal cells into neural-like cells

AIM: To investigate the process of human bone marrow stromal cells (hBMSCs) differentiation into neural-like cells and to determine the role of 26S proteasome in neuronal differentiation. METHODS: Purified hBMSCs were treated with β-mercaptoethanol (β-ME) for 1 day and retinoic acid (RA) for 3 days, followed by growth factor (10 μg/L bFGF or 20 μg/L NGF) for another 3 days. Immunofluorescence was performed to detect the expression of nestin (a neural precursor cells marker), Tuj1 (a premature neuronal marker), and neurofilament (NF, a mature neuronal marker) at all stages of induced differentiation. Immunostaining and RT-PCR were used to analyze the expression of 26S proteasome during neuronal differentiation of hBMSCs. To further confirm the role of 26S proteasome in hBMSCs differentiation, cells were treated with β-ME/RA and then followed by protesome inhibitor MG132 and growth factor. Immunostaining was performed to detect NF-positive cells. RESULTS: Quantification results showed that the untreated cells were almost never positive for nestin, Tuj1 and NF. After treated with β-ME/RA, the numbers of nestin-positive cells (34.41%±1.27%) and Tuj1-positive cells (27.79%±1.27%) were increased. Notably, the numbers of NF-positive cells were significantly increased to 56.72%±2.4% after induction with β-ME/RA/GF. Immunofluorescence analysis showed that undifferentiated hBMSCs cells were weakly stained by antibody against 26S proteasome, but the numbers of cells with high-intensity of 26S proteasome were increased after treated with β-ME/RA. The RT-PCR result of 26S proteasome further confirmed that the mRNA level of the cells differentiated by β-ME/RA (1.33), as well as by β-ME/RA/GF (1.77), was significantly increased compared to the undifferentiated cells. Moreover, hBMSCs incubated with protesome inhibitor MG132 significantly decreased the numbers of NF-positive cells (37.59%±1.52%). CONCLUSION: After induction with β-ME/RA/GF, hBMSCs can be differentiated into neural-like cells, which is concomitant with the increase in 26S proteasome expression. Inhibitor of 26S protesome prevents hBMSCs differentiation, suggesting that 26S proteasome may be involved in the differentiation of hBMSCs into neural-like cells.     

Effects of ginsenoside Rb1 on proteome from hippocampus of rats with epilepsy induced by Coriaria lactone

AIM: To explore the mechanism of development of Coriaria lactone (CL)-induced epilepsy and the neuroprotective effects of ginsenoside Rb1 (GRb1) on the process of epilepsy by identifying the proteins related to CL and GRb1 in rat hippocampus with two-dimensional electrophoresis (2-DE) technology.METHODS: The rat model of epilepsy was induced by CL. The rats in control group, CL epileptic group and GRb1 +CL epileptic group were decapitated and the hippocampus were collected. Two-dimensional electrophoresis was applied to separate the proteins from each group. Analysis of 2-DE maps was used to determine differential expression of proteins by ImageMaster 2D Platinum 5.0, and some differentially expressed protein spots were picked up for further identification by matrix-assisted laser sorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS).RESULTS: Six proteins were successfully identified. Among these, the expression of brain creatine kinase, endophilin-A1 and UPF0628 protein C10orf96 homolog was lower in GRb1+CL epileptic group than those in CL epileptic group. The expression of cytochrome P-450, phosducin-like protein and bridging integrator 3 protein was lower in GRb1+CL epileptic group than those in control group.CONCLUSION: The protein expression profiles are significantly different among control group, CL epileptic group and GRb1+CL epileptic group. The identified proteins may be related to the neuroprotective effects of GRb1. Among these, brain creatine kinase, endophilin-A1 and UPF0628 protein C10orf96 homolog may be related to CL-induced seizures.     

葡萄叶片蛋白质双向电泳技术体系的建立

现对葡萄叶片中总蛋白质的双向电泳技术体系进行了初步探讨,比较了不同等电聚集程序、不同pH胶条以及不同SDS-PAGE凝胶浓度的双向电泳效果。结果表明:葡萄叶片蛋白质使用等电聚焦程序B、pH范围为4~7的胶条和12%的SDS-PAGE凝胶可以得到较为理想的双向电泳分析结果;采用7 cm胶条最大可以分离出143个有效蛋白质点。     

Comparative proteomics analysis of human osteosarcomas and benign tumors of bone

AIM: To analyze the proteomic components of the tissue from human osteosarcoma and benign tumor of bone, and to search the diagnostic markers of osteosarcoma. METHODS: Five samples of osteosarcoma and 5 additive samples from benign bone tumor were analyzed by a series of methods including immobilized pH gradient two-dimensional polyacrylamide gel electrophoresis (2DE), deep purple staining. The ImageMaster 2DE analysis-software, as well as peptide mass fingerprint based on matrix-assisted laser desorption/ionization time of flying mass spectrometry (MALDI-TOF-MS) and SWISS-PROT database searching were used for data processing. RESULTS: The average spots in osteosarcoma and the benign tumor of bone were 1 386±101 and 1 270±202, respectively. 22 peptide mass fingerprint (PMF) maps were obtained by MOLDI-TOF-MS and identified by searching the SWISS-PROT database. Compared with those in benign tumor of bone, 15 proteins were significantly up-regulated, especially zinc finger protein 133 (Znf133), lamin B and tailless complex polypeptide 1 (TCP-1). 7 down-regulated proteins were observed, with the absence of protein kinase C inhibitor protein 1 (KCIP-1) in osteosarcoma. CONCLUSION: The results suggest that an obviously differential proteomic expression exists between the osteosarcoma and benign tumor of bone. The overexpression of Znf133, lamin B, TCP1 and low-expression of KCIP-1 may play an important role in the development of osteosarcoma, and may serve as diagnostic markers/therapeutic targets of osteosarcoma.     

Proteomic study of myocardial mitochondria with ischemia/reperfusion injury and pinacidil postconditioning in isolated rat hearts

AIM: To investigate the protective effect of pinacidil postconditioning on rat myocardium suffering ischemia/reperfusion injury by mitochondrial proteomics. METHODS: Langendorff apparatus was used to establish the model of myocardial ischemia/reperfusion injury. Sprague-Dawley rats were randomly divided into 2 groups: pinacidil postconditioning group (Pina group) and ischemia/reperfusion injury group (I/R group). After 20 min of perfusion with K-H solution, the perfusion was suspended for 40-min (global ischemia) follow by 60 min of reperfusion in I/R group. In Pina group at the end of 40 min global ischemia, the isolated hearts were perfused with K-H solution containing pinacidil (50 μmol/L) for 2 min followed 58-min perfusion with regular K-H solution. Total proteins extracted from the mitochondria were applied to the two-dimensional gel electrophoresis (2-DE). The differentially expressed protein spots over 2 times were evaluated by a software. Then they were subjected to in-gel digestion, and analyzed by spectrometry. RESULTS: The expression levels of NDUFA10, NDUFS2 and NDUFV2 were elevated but those of IDHA and ECH1 were decreased in Pina group compared with I/R group. Interestingly, 2 spots in the 2-DE map were identified as ATPase subunit δ. The expression levels of one spot was elevated, while the other was decreased. CONCLUSION: Pinacidil postconditioning may decrease the degree of increased expression levels of NDUFA10, NDUFS2 and NDUFV2, promote the expression of IDHA and ECH1, and induce the phosphorylation of ATPase subunit δ, which may be related to the protective mechanism of pinacidil postconditioning.     

Changes of expressive proteome of renal tissues in chronic intermittent hypoxic rats

AIM: To obtain the two-dimensional gel electrophoresis maps of renal tissue proteins for identifying the differentially expressed proteins in the chronic intermittent hypoxic rats. METHODS: The rat model of chronic intermittent hypoxia was established. The rats lived in the normoxia environment were used for control. The proteins in the renal tissues underwent two-dimensiona1 gel electrophoresis with immobiline pH gradient isoelectric focusing as the first and vertical SDS-PAGE as the second dimension. Analysis of 2-DE maps was performed to determine the differential expression of proteins between the two groups by the software of ImageMaster 2D Platinum V5.0, in which 4 protein spots expressed differentially were picked up for further identification by MALDI-TOF-MS. RESULTS: Matched and compared with those in control group, 112 protein spots were determined in chronic intermittent hypoxia group. By MALDI-TOF-MS, 4 protein spots with the highest differentially expressive levels were identified as ATP synthase delta subunit mitochondrial precursor, hexokinase, catechol O-methyltransferase and apurinic/apyrimidinic endonudease/redox factor-1. The functions of these identified proteins are involved in cellular energy metabolism, apoptosis, signal transduction, anti-cell injury and hormone metabolism. CONCLUSION: There are obvious differences in expressive proteomes in renal tissue between normoxic and chronic intermittent hypoxic rats. Proteomics can serve as a new approach in the study of obstructive sleep apnea-hypopnea syndrome for discovering new therapeutic targets.     

番茄子叶总蛋白双向电泳体系的建立

通过对IPG胶条梯度、上样方式、上样量、聚焦条件等4方面条件的优化,建立了番茄子叶总蛋白双向电泳体系,即采用TCA丙酮沉淀法提取番茄子叶总蛋白,选用24 cm pH3-7NL的IPG胶条,采用水化上样,上样量300 μg,按聚焦程序Ⅰ或Ⅱ聚焦后进行双向电泳分离和银染染色。若采用制备胶,以获取高含量蛋白点,则将上样量提高至1.5 mg,按聚焦程序Ⅲ进行聚焦后进行双向分离,并采用胶体考马斯亮蓝染色。采用该优化的体系可以获得分辨率高、重复性好的双向电泳图谱。     

北海道黄杨叶片应答低温胁迫的蛋白质组分析

 采用双向电泳的蛋白质组学方法分析了北海道黄杨叶片蛋白质对低温胁迫的应答反应。北海道黄杨植株在室外种植，从2008年10月—2009年2月每月提取叶片总蛋白。在考马斯亮蓝染色的2-DE胶上发现36个表达量显著差异蛋白点，其中通过质谱鉴定出19个蛋白质，包括已知的和新鉴定的低温胁迫相关蛋白质。这些鉴定出的蛋白质涉及多个生理过程，如能量与代谢、调控、防御应答等，同时这些蛋白质的表达模式与生理生化变化模式相一致。     

Comparative proteomics of myocardial mitochondrial proteins in aging rats

AIM:To identify the proteins related to aging in the mitochondria of the heart. METHODS:Mitochondria were isolated from the hearts of adult (10-week) and old (12-month) rats (n=3). Total proteins extracted from the mitochondria were applied to the two-dimensional gel electrophoresis. The differentially expressed protein spots evaluated by a software were subjected to in-gel digestion, and analyzed by the matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS). ATP content in the heart was also measured. RESULTS:Eighty-four differentially expressed protein spots were observed, and fifteen of them were analyzed by MALDI-TOF- MS. Four proteins including creatine kinase, peroxiredoxin 2, Tu translation elongation factor and isocitrate dehydrogenase were up-regulated and 11 proteins including succinate dehydrogenase, malate dehydrogenase, aconitate hydratase, NADH dehydrogenase, ATP synthase H+ transporting, ATP synthase beta chain, heat shock protein 60, glucose-regulated protein 78, prohibitin, Aldehyde dehydrogenase 2 and voltage-dependent anion channel exhibited down-regulation in the aging group compared to the adult one. ATP content in the heart of old rats was significantly reduced as compared to that in adult rats (n=5, P<0.01). CONCLUSION:Significant changes in the mitochondrial protein expression in the aging heart were identified by the 2-DE electrophoretogram with high resolution and reproducibility. The functions of these identified proteins need to be further investigated.     

Effect of integrin α2 on adhesion of neuroblastoma cells to co llagen

AIM:To study the effect of integrin α2 on adhesion of SK-N-SH neuroblastoma cells to collagen.METHODS:Adhesion of the SK-N-SH cells to immobilized collagen w as tested with various concentration of Mg2+,Ca2+ and with 10 μg/L anti-α2 monoclonal antibody (mAb) 6F1.A570 was detected as adhesio n cell numbers.RESULTS:Mg2+-dependent adhesion of SK-N-SH cells to type I collagen was increased significantly,with peak adhesion at concentration of 1 mmol/L Mg2+.A570 with or without Mg2+ was 0.59±0.03 and 0.25±0.01 respectively (P<0.01).No effect of Ca2+ was found on SK-N-SH cell adhesion.6F1 (10 mg/L) blocked the adhesion completely.CONCLUSION:Integrin α2 regulates neuroblastoma cells adhesion t o collagen and suggest that it may play a role in tumor cell migration,invasion and metastasis.