腺病毒载体转染人HO-1基因增强成人胰岛细胞抗凋亡和胰岛素释放功能的研究

目的了解腺病毒载体转染人HO-1基因对体外培养的成人胰岛的作用,探索基因治疗在胰岛移植中的潜在应用价值。方法将成人胰岛分离纯化后分为3组:转染人HO-1基因组(Ad-HO-1组)、转染EGFP基因组(Ad-EGFP组)及对照组,采用携带人HO-1基因及EGFP基因的腺病毒作为载体对体外培养的成人胰岛进行转染,通过形态学观察、胰岛素释放试验及肿瘤坏死因子(TNF)α及放线菌酮诱导48 h后流式细胞仪检测凋亡。结果Ad-HO-1组的胰岛在高糖刺激下胰岛素分泌量为270 m IU/L±89 m IU/L,高于对照组(182 m IU/L±59 m IU/L)和Ad-EGFP组(189 m IU/L±88 m IU/L,P<0.05);诱导后Ad-HO-1组凋亡细胞的发生率为63%±11%,对照组为91%±11%,两组比较,P<0.01。结论使用腺病毒作为载体对体外培养的成人胰岛转染HO-1基因能够增加胰岛的抗凋亡能力、促进胰岛素的分泌。     

Protection of rat islet viability following heme oxygenase-1 gene transfection via adenoviral vector in vitro

Objective： To investigate the effect of Heme oxygenase-1 （HO-1） gene transfection on the viability of cultured rat islets, and to explore the potential value of HO-1 gene in islet transplantation. Methods：Recombinant adenovirus vector containing human HO-1 gene（Ad-HO-1 ） or enhanced green fluorescent protein gene（Ad-EGFP） was generated by using AdEasy system respectively. The rat islets were transfected with Ad-HO-1, Ad-EGFP or blank vector and then cultured for 7 days. Transfection was confirmed by expression of EGFP and human HO-1 protein detected by fluorescence photographs and western blot, respectively. The insulin release upon different concentration of glucose stimulation was detected using insulin radioimmunoassay kit, and stimulation index（SI） was calculated. Glucose-stimulated insulin release was used ＇to assess islet viability. Results：Adenovirus vector successfully transferred HO-1 gene to rat islet cells in vitro, and the insulin release upon high level of glucose stimulation and stimulation index （SI） of Ad-HO-1-infected islets were significantly higher than those of Ad-EGFP-infected islets and control islets （P 〈 0.05）. Conclusion： Adenovirus-mediated HO-1 gene transfection is a feasible strategy to confer cytoprotection and therefore protect the viability of cultured rat islets.     

腺病毒介导外源基因转染大鼠胰岛移植物的实验研究

目的探讨携带外源基因的腺病毒在体外有效感染大鼠胰岛及外源基因在胰岛中的表达。方法用携带人血红素氧合酶-1基因(hHO-1)及绿色荧光蛋白基因(GFP)的腺病毒在体外以不同MOI感染大鼠胰岛,荧光显微镜观察GFP的表达及Western检测hHO-1蛋白来确定转染结果,并观察外源基因表达持续的时间。结果腺病毒载体在体外能将外源基因有效转入到大鼠胰岛细胞,转染的基因能稳定表达。结论腺病毒载体在体外可以有效感染大鼠胰岛,为基因修饰胰岛移植物以提高胰岛移植效果奠定了实验基础。     

Akt基因治疗大鼠肝硬化门静脉高压症

目的:探讨肝硬化时肝组织内Akt和eNOS的活化是否受到抑制以及腺病毒介导的Akt基因治疗门静脉高压症的可行性.方法:以细胞内同源重组法构建复制缺陷型重组腺病毒Ad-myr-HA-Akt和Ad-EGFP.采用四氯化碳复合法制备肝硬化门静脉高压症大鼠模型.取10只正常大鼠作为对照,另取40只肝硬化大鼠随机均分为4组:未处理组、Akt治疗组、EGFP组和生理盐水组.后3组分别经尾静脉分别注射Akt重组腺病毒、Ad-EGFP和生理盐水后,3 d后,分别测定各组的门静脉压力、平均动脉压和心率.用免疫印迹法检测各组大鼠肝组织内Akt,p-Akt,eNOS,p-eNOS蛋白的表达;硝酸还原酶法检测各组肝内NO含量.EGFP组于转染后3 d处死大鼠,取肝、心、肺、肾、脑、脾和睾丸,快速冰冻切片,观察绿色荧光蛋白的表达情况.结果:Ad-myr-HA-Akt和Ad-EGFP经纯化后滴度分剐为5.5×1011vp/mL和6.0×1011 vp/mL.肝硬化大鼠肝内Akt和eNOS的活化均受到抑制,肝内NO生成减少,门静脉压力升高.Akt重组腺病毒治疗能使受到抑制的Akt和eNOS磷酸化得到恢复,同时增加肝内NO含量,降低门静脉压力.而经Ad-EGFP和生理盐水处理组,Akt和eNOS磷酸化不能恢复,肝内NO含量和门静脉压力与未经治疗大鼠相似.EGFP组在Ad-EGFP转染后3 d肝组织中可见大量绿色荧光,肺和肾组织中仅见少量荧光,而其他实质器官未见EGFP表达.结论:肝硬化时,大鼠肝内Akt和eNOS的活化均受到抑制,导致NO生成减少而肝内血管阻力增加,表现为门静脉压力升高.以腺病毒介导的Akt基因治疗门静脉高压症可行.     

Rapid Construction of EGFP Labled Recombinant Adenovirus Containing hVEGF165 and Its Expression in Haematopoietic Cells

Vascular endothelial growth factor(VEGF) isan endothelial cell specific mitogen that plays an im-portantrole in normal and pathological angiogenesis.More and more reports have revealed the significantregulation of embryonic and postnatal hematopoiesisby VEGF[1— 4 ] .Though the application of recombi-nant VEGF in many studies hasmade some inspiringresults,there still exists problems such as the expen-sive price and difficulties in procession of delivery.However,by using adenoviral vector,…     

载EPO腺病毒的PLGA纳米纤维支架在体内促进骨缺损修复作用

目的: 将促红细胞生成素(EPO)腺病毒局限在应用部位,观察其在体内的促进骨形成作用。方法: 采用冷冻干燥法,将增强型绿色荧光蛋白(EGFP)腺病毒与聚乳酸羟基乙酸共聚物(PLGA)纳米纤维支架复合作为实验组(PLGA/Ad-EGFP组),以等剂量的EGFP腺病毒为对照组,分别感染骨髓基质细胞(BMSCs),以BMSCs感染EGFP的荧光细胞面积比例检测病毒活力。采用Picogreen dsDNA定量检测试剂盒检测病毒释放动力学。将EPO腺病毒与PLGA纳米纤维支架冻干复合作为实验组(PLGA/Ad-EPO组),以单纯骨缺损为对照组,植入大鼠颅骨缺损处,在第4和8周采用Micro CT及组织学HE染色检测EPO腺病毒的新生骨面积百分比。结果: PLGA/Ad-EGFP组荧光细胞面积比例明显高于对照组(P<0.05);腺病毒在PLGA上呈突释曲线,第1小时存留53.0%±5.6%,第16小时存留20.0%±3.3%。与对照组比较,PLGA/Ad-EPO组在第4周促进红细胞生成,并在第4及8周大鼠颅骨缺损修复,新生骨面积百分比达到25.0%±5.7%及35.0%±6.3%(P<0.05)。结论: 应用冻干法将腺病毒与PLGA复合能够有效保存病毒活性, PLGA /Ad-EPO纳米纤维支架能够在一定程度上促进骨缺损修复。     

大鼠胰岛细胞分离纯化的实验研究

目的寻找简便、高效的大鼠胰岛分离纯化方法,并对纯化胰岛细胞的基本生物学状况进行鉴定。方法采用胰管内注射胶原酶水浴消化以及Ficoll400不连续密度梯度离心法纯化,用DTZ染色计算胰岛细胞的纯度;用AO/PI染色计算胰岛细胞存活率;通过体外葡萄糖刺激胰岛素分泌试验和糖尿病大鼠移植判定胰岛细胞功能。结果纯化后获得(738±193)个胰岛细胞/每只胰腺,纯度为(77±13)%,纯化后细胞形态完好,活度大于95%,体外葡萄糖刺激胰岛素分泌实验,低糖情况下胰岛素分泌量为(24.31±5.47)mIU/L,高糖情况下为(37.62±4.29)mIU/L,两者有显著性差异(P<0.05),胰岛移植后,实验组48h后血糖值降至正常,维持(3.9±1.7)d。结论采用胰管内胶原酶灌注进行大鼠胰岛分离及Ficoll400不连续密度梯度法纯化可获得较高纯度和活度的胰岛细胞。     

胰岛素信号转导基因表达的改变与α细胞胰岛素抵抗的实验研究

目的探讨高脂喂养及大剂量链脲佐菌素(STZ)去β细胞处理的肥胖大鼠胰岛α细胞信号转导通路分子的表达情况及其可能机理。方法 30只 SD 大鼠分为高脂饲料喂养的肥胖(HF)组和普通饲料喂养的正常对照(NC)组。喂养20周后,(1)检测空腹血胰岛素(Ins)、胰高糖素(Glc)、游离脂肪酸(FFA)、甘油三酯(TG)水平。(2)正常血糖高胰岛素钳夹试验评价外周胰岛素抵抗程度(NC 组7只,HF 组7只)。(3)NC 组和 HF 组各8只,给予大剂量链脲佐菌素(STZ)去β细胞处理,即 NC-B 组,HF-B 组。使用胰岛素控制血糖,5d 后处死动物,分离胰岛细胞。(4)采用实时定量聚合酶链反应方法比较两组大鼠α细胞 Glc、胰岛素受体底物-1(IRS-1)、胰岛素受体底物-2(IRS-2)、磷酯酰肌醇3激酶(PI3K)的 mRNA 表达的情况。结果(1)HF 组葡萄糖输注率(GIR)明显低于NC 组(5.3 mg·min~(-1)·kg~(-1)±1.2 mg·min~(-1)·kg~(-1)vs 13.6 mg·min~(-1)·kg~(-1)±1.7 mg·min~(-1)·kg~(-1),P<0.01),HF 组血 FFA、Ins 及 Glc 水平显著高于 NC 组(FFA 508(394～622)μmol/L vs 325(240～410)μmol/L,Ins 23.7(14.0～33.4)mIU/L vs 11.5(3.6～19.4)mIU/L;Glc 345(298.6～391.4)pg/ml vs 256(226.4～285.6)pg/ml;P<0.05);(2)HF-B 组比 NC-B 组α细胞 Glc mRNA 的表达高34.2%±2.1%,IRS-2及 PI3K mRNA 分别低28.5%±1.8%、21.3%±1.6%(均 P<0.01),而IRS-1仅降低7.0%±1.2%(P>0.05)。(3)相关分析显示,HF 组血 FFA 水平与 GIR 呈负相关(r=-0.675,P<0.01);且与α细胞 IRS-2 mRNA 表达也呈负相关(r=-0.458,P<0.05)。结论高脂饮食诱导的去β细胞肥胖大鼠胰岛α细胞存在胰岛信号转导分子表达降低,且与血 FFA 水平升高有关。     

嵌合性5型腺病毒载体Ad5/F35体外转染大鼠骨髓间充质干细胞的研究

目的:研究携带35型腺病毒纤毛的嵌合性5型腺病毒载体Ad5/F35能否有效地将增强型绿色荧光蛋白(eGFP)基因体外转染大鼠骨髓间充质干细胞(BMSCs),并观察eGFP基因在大鼠BMSCs内持续表达的时间.方法:贴壁培养法分离、扩增大鼠BMSCs.用带有eGFP基因的Ad5/F35(Ad5/F35-eGFP)分别以1、10、100、1000的感染复数(MOI)转染第2代大鼠BMSCs;荧光倒置显微镜和流式细胞仪(FCM)检测eGFP基因的转染效率与表达水平,观察细胞生长状态以评估病毒对大鼠BMSCs基本生物学特性的影响;对MOI=100的病毒转染的大鼠BMSCs在转染后第2、7、14、21、30天分别用FCM检测大鼠BMSCs内eGFP的表达情况.结果:MOI在1到1000范围内,eGFP基因转染效率和表达水平与Ad5/F35-eGFP的MOI呈正向剂量相关性.MOI=100的病毒可转染90%左右的大鼠BMSCs,且eGFP基因在1个月内均有表达.MOI为1、10、100的病毒不影响大鼠BMSCs的活力和增殖能力.结论:Ad5/F35可以高效地将eGFP基因体外转染大鼠BMSCs,eGFP基因可持续表达1个月.本研究为Ad5/F35作为BMSCs的基因转移和表达载体进行细胞治疗与基因治疗提供了实验依据.     

Effects of mature Sertoli cells on allogeneic islets cocultured in vitro

INTRODUCTIONNowadays 180 million people suffer from dia-betes mellitus in world. An exogenous insulininjection has been the gold standard treatment fortype I diabetic patients, which is complicated andcould never completely correct the underlying loss ofislet cells and the resulting unregulated glucose lev-els. Islet transplantation seems to be an almost idealtherapy for insulin-dependent patients [1]. However,in isolate islet transplants the early clinical islet graftloss in 1 month is a…     

Suicide gene therapy using adenovirus vector for human oral squamous carcinoma cell line in vitro

Recently, suicide gene therapy using the herpes simplex virus thymidine kinase (HSVtk) gene followed by ganciclovir (GCV) administration was evaluated for the treatment of cancer. The purpose of this study was to investigate the effectiveness of suicide gene therapy using the replication-deficient recombinant adenovirus vector for human oral squamous carcinoma cell lines. To evaluate transduction efficiency, each cell line was transduced in vitro with an adenovirus vector containing the beta-galactosidase gene. By 24 hours after transduction, nearly 100% of the cells were transduced at a multiplicity of infection (MOI) of 10, and from 30 to 10% at an MOI of 1. Next, each cell line was transduced with an adenovirus vector containing the HSVtk gene, and a subsequent administration of GCV for the assessment of suicide gene therapy. A subsequent administration of GCV resulted in complete tumor cell death. In addition, we conducted a morphological analysis of that cell death using video-enhanced contrast differential interference contrast microscopy, and we observed that it included both apoptosis and necrosis after HSVtk gene and GCV treatment. These results suggest that adenovirus-mediated suicide gene therapy induced remarkable cytotoxicity with a bystander effect in human oral squamous cell carcinoma thus suggesting an effective treatment strategy for that tumor.     

成人胰岛细胞的分离与纯化

目的 探讨体外分离与纯化成人胰岛细胞的方法与可行性,为胰岛细胞移植治疗1型糖尿病提供大量高质量的胰岛细胞。方法获取的成人胰腺组织称重后,采用V型胶原酶消化法分离;再用Ficoll间断密度梯度离心纯化法纯化;在DTZ染色显微镜下,评价胰岛细胞的数量、纯度;并用体外培养、放射免疫测定胰岛素法鉴定胰岛细胞活性。结果成人胰腺经胶原酶消化分离后,胰岛平均收获量（3600±447）个／g胰腺;Ficoll间断密度梯度离心纯化后,胰岛平均收获量（2140±207）个／g胰腺,纯度〉70％;成人胰岛细胞培养2、4、6d后,测定其培养液中基础胰岛素浓度（mIU·L^-1·100^-1）分别为（3．302±1．63）、（3．504±1．10）、（2．921±1．13）。结论胶原酶消化法、Ficoll间断密度梯度离心纯化法分离纯化成人胰岛是有效的方法。     

微囊化大鼠胰岛细胞的冷冻保存

目的探讨海藻酸钠-聚赖氨酸-海藻酸微囊在胰岛细胞冷冻保存过程中的作用。方法将分离纯化后的大鼠胰岛细胞分为微囊化组和游离组。经冷冻保存1月后在RPMI 1640中培养过夜,分别测定两组的胰岛细胞回收率、胰岛细胞直径并进行胰岛素刺激释放试验。结果微囊组胰岛细胞回收率为98．2％±1．4％,较游离组71．6％±2．9％显著提高 (P<0．05)。在高糖(16．7 mmol／L)刺激下,微囊组胰岛素分泌量较游离组高(22．6±1．8 mU/Lvs 11．7±1．5 mU/L,P<0．05)。在含有茶碱的高糖溶液中,微囊组的刺激指数为游离组的3倍。结论海藻酸钠-聚赖氨酸-海藻酸微囊可显著提高胰岛细胞冷冻保存后的回收率,并改善胰岛细胞的功能。     

犬胰岛的分离与纯化

目的探讨影响胰岛分离与纯化结果的相关因素,寻找获得足够数量、高纯度、具有活性的胰岛细胞的方法,为临床胰岛移植应用提供实验基础。方法寻找自动分离技术连续分离22只犬的胰岛,连续性密度梯度离心法纯化胰岛,观察分离纯化出来的胰岛细胞大体形态、超微结构,用葡萄糖刺激释放实验检验其活性。结果纯化前胰岛计数平均为（155040±310）IEQ／胰腺,纯化后的胰岛平均计数为（74200±185）IEQ／胰腺,纯度约为（89．4±2．6）％,回收率约为（47．8±1．3）％,活率达到（93．0±1．7）％。胰岛分离纯化的结果无论在数量上还是在质量上都随着分离技术的不断更新,操作技术的娴熟而有很大提高。葡萄糖刺激释放实验显示低糖组与高糖组比较P〈0．001,提示分离纯化后获得的胰岛功能状态良好。结论从犬中分离和纯化出足够数量的胰岛细胞,可用于临床研究。     

大剂量抗氧化剂对高脂饲养大鼠胰岛β细胞分泌功能的影响及机制

目的:探讨大剂量抗氧化剂-N-乙酰半胱氨酸(N-acetyl-l-cysteine,NAC)对高脂饲养大鼠胰岛β细胞分泌功能的影响及可能机制。方法:将59只8周龄SD大鼠随机分为正常饲料组(NC组)、高脂饲料组(HF组)和高脂 NAC组(NAC组)。饲养20周,(1)测血浆及胰腺组织丙二醛(MDA)和还原型谷胱甘肽(GSH)水平;(2)正常血糖高胰岛素钳夹实验,评价外周组织胰岛素抵抗程度;(3)胰岛细胞表面灌注实验,评价离体胰岛β细胞动态分泌功能;(4)实时荧光定量PCR方法比较各组大鼠胰岛素受体底物-1(IRS-1)、胰岛素受体底物-2(IRS-2)和葡萄糖转运子-2(Glut-2)mRNA表达的变化。结果:(1)HF组血浆及胰腺MDA水平明显高于NC组,GSH水平低于NC组,NAC可以改善以上变化;(2)HF组葡萄糖输注率(GIR)比NC组降低(P<0.01),用NAC后GIR明显改善(P<0.01);HF组葡萄糖刺激的胰岛素分泌(GSIS)功能下降,用NAC后可逆转上述变化;(3)HF组胰岛细胞IRS-1、IRS-2、Glut-2mRNA表达降低42.3%、28.1%、22.9%(P均<0.05);NAC组胰岛细胞IRS-1、IRS-2、Glut-2 mRNA表达与HF组相比增加40.2%、30.2%,19.1%(P均<0.05)。结论:大剂量抗氧化干预治疗能改善胰岛细胞胰岛素信号传导,逆转高脂饲养导致的大鼠胰岛细胞分泌功能紊乱,其机制可能与NAC纠正机体氧化及抗氧化失衡有关。     

简便快捷的小鼠胰岛分离纯化方法研究

目的 探讨小鼠胰岛分离与纯化的方法.方法 采用多点注射灌注胶原酶法消化胰腺,不连续密度梯度离心联合人工挑取的方法分离、纯化胰岛.双硫腙特异性染色后计算胰岛产量及纯度.葡萄糖刺激后测定培养上清液胰岛素水平检测胰岛功能.结果 (1)每只小鼠采用上述分离、纯化法平均得到(114±15)个胰岛,平均纯度为(77.12±3.23)％,胰岛细胞存活率＞90％; (2)分离、纯化的胰岛培养上清液中胰岛素水平在无糖、低糖(2.8 mmol/L)和高糖(22.2 mmol/L)刺激下分别为(23.80±3.52) mIU/L、 (67.57 ±4.04) mIU/L和(164.32±10.75) mIU/L,各组间比较,差异有统计学意义(P＜0.05).两两比较,低糖组的胰岛素水平为无糖组的2.84倍(P＜ 0.05),高糖组的胰岛素水平为低糖组的2.43倍(P＜0.05),高糖组的胰岛素水平为无糖组的6.90倍(P＜0.05).结论 采用多点注射灌注胶原酶法消化胰腺,不连续密度梯度离心联合人工挑取的方法分离、纯化的小鼠胰岛产量及纯度较高,形态完整,不同浓度葡萄糖刺激后胰岛素分泌反应良好,是一种简便、快捷的小鼠胰岛分离方法.     

Blockade of the OX40/OX40L pathway and induction of PD-L1 synergistically protects mouse islet allografts from rejection

Background OX40/OX40 ligand （OX40/OX40L） and programmed death-1/programmed death ligand-1 （PD-1/PD-L1） co- stimulator/signals play important roles in T cell-induced immune responses. The aim of this study was to investigate the roles of OX40/OX40L and PD-1/PD-L1 costimulatory pathways in mouse islet allograft rejection. Methods Lentiviral vectors containing OX40L siRNA sequences and an adenovirus vector containing the PD-L1 gene were constructed. The streptozotocin-induced model of diabetes was established in C57BL/6 （H-2b） mice. Diabetic C57BL/6 mice were randomly allocated into five groups： group 1, untreated control; group 2, Ad-EGFP treatment; group 3, Ad-PD-L1 treatment; group 4, OX40L-RNAi-LV treatment; group 5, OX40L-RNAi-LV combined with Ad-PD-L1 treatment. Lentiviral vector and the adenovirus vector were injected, singly or combined, into the caudal vein one day before islet transplantation. The islets of DBA/2 （H-2d） mice were transplanted into the renal subcapsular space of the diabetic recipients. Recipient blood glucose and the survival time of the allografts were monitored. Antigen-specific mixed lymphocyte reaction was also evaluated.     

Effects of adenovirus mediated vascular endothelial growth factor gene transfer on reconstitution of hematopoiesis in post-bone marrow transplantation mice

Background Bone marrow transplantation (BMT) conditioning procedure is considered as the cause of damage to bone marrow microvasculature and the delay of hematopoiesis recovery. However, hematopoiesis regulation post BMT by vascular endothelial growth factor (VEGF) has not yet been studied. In this study, adenovirus were used to investigate the effects of VEGF gene transfer on preventing damages to bone marrow microenvironment and its promotion of hematopoiesis in post-BMT mice.Methods Recombinant adenovirus (Ad)-enhanced green fluorescent protein (EGFP)/hVEGF165 was injected via tail vein into BALB/c mice undergoing syngeneic BMT. During the different phases post BMT, the distribution of adenovirus and the plasma levels of hVEGF were measured as well as the numbers of white blood cells (WBC), platelet (PLT) and red blood cells (RBC) in peripheral blood. At the same time, the mice were injected with Chinese ink via tail vein, following which the tibias were separated and were used for analysis of bone marrow microvasculature surface area and cellularity.Results Significant expression of EGFP and hVEGF was observed in multiple organs at different phases post BMT, and the plasma level of hVEGF was up to (866.67±97.13) pg/ml. The recovery of WBC, PLT and RBC of the group treated with recombinant adenovirus Ad-EGFP/hVEGF165 were significantly more rapid than those of other BMT groups （P&lt;0.05, respectively）. At the 20th day post BMT, the percentage of bone marrow microvasculature surface area in group treated with VEGF ［(61.2±4.0)%］ returned to normal level ［(62.0±5.0)%, P&gt;0.05］. The restoration of hematopoiesis was retarded more than that of microvasculature. The cellularity of bone marrow in each group was still lower than that of normal control ［(62.3±4.0)%, P&lt;0.05］ at the 30th day post BMT, but the percentage in group treated with VEGF at the 20th and 30th days post BMT ［(46.5±5.0)% and (55.1±4.5)%］ exceeded those of other BMT groups (P&lt;0.05, respectively).Conclusion VEGF gene transfer mediated by adenovirus may protect the hematopoietic microenvironment to promote the restoration of hematopoiesis in post-BMT mice.     

表皮生长因子对体外长期孵育保存的人胎胰岛的支持作用

目的：研究表皮生长因子(EGF)对促进人胎胰岛增殖与分泌功能．方法：12个人胎胰岛分别在含有EGF(实验组)和不含有EGF(对照组)的培养基中孵育，观察胰岛B细胞的分布，测定培养基中和细胞内胰岛素浓度和胰岛素释放量．结果：培养结束后实验组胰岛B细胞明显高于对照组；培养基和胰岛B细胞中胰岛素释放量实验组高于对照组．结论：培养液中加入EGF能延长胰岛细胞存活期、促进胰岛细胞增殖和分泌功能．