The intracellular mechanism of alpha-fetoprotein promoting the proliferation of NIH 3T3 cells

AIM: The existence and properties of alpha-fetoprotein (AFP) receptor on the surface of NIH 3T3 cells and the effects of AFP on cellular signal transduction pathway were investigated. METHODS: The effect of AFP on the proliferation of NIH 3T3 cells was measured by incorporation of 3H-TdR. Receptor-binding assay of 125I-AFP was performed to detect the properties of AFP receptor in NIH 3T3 cells. The influences of AFP on the [cAMP]i and the activities of protein kinase A (PKA) were determined. Western blot was used to detect the change of K-ras P21 protein expression. RESULTS: The proliferation of NIH 3T3 cells treated with 0-80 mg/L of AFP was significantly enhanced. The Scatchard analysis indicated that there were two classes of binding sites with KD of 2.722 x 10(-9)M (Bmax=12810 sites per cell) and 8.931 x 10(-8)M (Bmax=119700 sites per cell) respectively. In the presence of AFP (20 mg/L), the content of cAMP and activities of PKA were significantly elevated . The level of K-ras P21 protein was upregulated by AFP at the concentration of 20 mg/L. The monoclonal antibody against AFP could reverse the effects of AFP on the cAMP content, PKA activity and the expression of K-ras p21 gene. CONCLUSION: The effect of AFP on the cell proliferation was achieved by binding its receptor to trigger the signal transduction pathway of cAMP-PKA and alter the expression of K- ras p21 gene.

Cell transformation as aberrant differentiation: Environmentally dependent sportaneous transformation of NIH 3T3 cells

NIH 3T3 cells, a mouse fibroblast cell line used as routine target cells for transfection experiments, undergo spontaneous transformation in our experiments after they form a confluent sheet in medium containing fetal bovina serum (FBS) or lower coneentrafcion of calf serum (CS). The transformation takes the form of foci of multiplying cells among the surrounding cells which have stopped cell division. However, no focus of transformed cells could be seen in medium containing high concentration (10%) of OS. Further experiments indicated that the frequency of transformation is highly dependent on the concentration of serum and the transformation in OS is changeable when the cells are passaged in FBS. 8H-thymidine autoradiography has been proved to be a sensitive measurement indicator for foous formation. Our results suggest that the high frequency of transformation and its dependence on confmenoy as well as on medium composition are characteristics of cell differentiation rather than mutation. The role of the NIH 3T3 cell line as a cancer-initiated cell population and its accelerated transformation by rat oncogene might be considered as a form of tumor promotion is discussed.

A PRIMARY OBSERVATION OF TPA EFFECT ON SSV-NIH3T3 CELLS IN SERUM-FREE MEDIUM

The effect of TPA, a potent tumor promoter, on SSV-NIH3T3 cells in serum-free medium was investigated. TPA stimulated DNA synthesis of SSV-NIH3T3 cells on the third day of culture in SFM. In SDS-PAGF of medium conditioned by TPA-treated SSV-NIH3T3 cells (in SFM+TPA), the amounts of four proteins of 31.0 Kd, 28.5 Kd, 25.5 Kd and 13.5 Kd strikingly increased over that of non-TPA-treated counterpart (in SFM). The PDGF-like activity was also detected in CM of SFM+TPA. When insulin and EGF were drown off the SFM+TPA (SFM-Ins-EGF+TPA), TPA lost its ability to stimulate DNA synthesis of SSV-NIH3T3 cells on the third day and SDS-PAGE of the conditioned medium showed that the amounts of the four proteins noted above grately reduced. However, cells in SFM-Ins-EGF+TPA were in almost the same growth condition as cells in complete SFM+TPA on the third day of culture. Results were discussed in the paper.

ELECTRON MICROSCOPIC OBSERVATION OF SIMIAN SARCOMA VIRUS TRANSFORMED NIH 3T3 CELLS IN VITRO

For electronic microscopic observation, we found SSV-transformed NIH 3T3 cells were different from non-transformed cells. In SSV-transformed NIH 3T3 cells nuclei cytoplasma ratio was increased and in cytoplasma the ribosomes (polyribosomes were attached to the swollen rough endoplasmic reticulum. It was likely that ribosomes were lined together functionally and structionally to produce specific protein (PDGF-like protein).

The anti-neoplastic effects of metformin modulate the acquired phenotype of fbroblast cells in the breast cancer-normal fbroblast co-culture system

Intracellular communications between breast cancer and fibroblast cells were reported to be involved in cancer proliferation,growth,and therapy resitance.The hallmarks of cancer fibroblast interactions,consisting of caveolin 1(Cav1)and mono-carboxylate ransporter 4(MCT4)(metabolic coupling markers),along with IL-6,TGFB,and lactate secretion,are considered robust biomarkers predicting recurrence and metastasis.In order to promote a novel phenotype in normal fibroblasts,we predicted that breast cancer cells could be able to cause loss of Cavl and increase of MCT4,as well as elevate IL 6 and TGF in nearby nomal fibroblasts.We created a co culture model using breast cancer(4T1)and normal fibroblast(NIH3T3)cell lines cultured under specific experimental conditions in order to directly test our theory.Moreover,we show that long-term co-culture of breast cancer cells and normal fibroblasts promotes loss of Cavl and gain of MCT4 in adjacent fibroblasts and increase lactate secretion.These results were validated using the monoculture of each group separately as a control.In this system,we show that me tformin inhibits IL-6 and TGFB secretion and re expresses Cavl in both cells.However,MCT4 and lactate stayed high after treatment with metformin.In conclusion,our work shows that co-culture with breast cancer cells may cause signifcant alterations in the phenotype and secretion of normal fibroblasts.Metformin,however,may change this state and affect fibroblasts'acquired phenotypes.Moreover,mitochondrial inhibition by metformin after 8 days of treatment,signi ficantly hinders tumor growth in mouse model of breast cancer.

The involvement of signaling activation of protein kinase C in gadolinium chloride-induced cell survival and cell cycle progression in NIH3T3 cells

In the present study, we investigated the activation of protein kinase C （PKC） family in mouse embryonic fibroblast NIH3T3 cells using gadolinium chloride as a representative lanthanide ion. With live cell imaging system and confocal laser scanning microscopy, we found that the treatment of 50 μM GdCI3 promoted cell survival under the condition of serum-starvation. Moreover, better cell attachment and cytoskeleton reorganization were also observed. Additionally, GdC13 treatment resulted in the phosphorylation of PKC family at different time points. Furthermore, bisindolylmaleimide （a PKCpan inhibitor） could efficiently reduce the level of phosphorylated PKCpan （βIISer660）, alleviating ERK activation induced by GdC13. This finding indicated that the PKC activation was involved in GdC13-induced MAPK/ERK signaling and thus might contribute to GdClβ-indueed cell cycle progression and cell survival.

Lanthanum chloride promotes proliferation of NIH 3T3 cells via cell cycle machinery

Lanthanum ions （La3＋） have been reported to exert profound effects on the proliferation of NIH 3T3 mouse embryonic fibroblasts. In the present studies, the pro-proliferative effect of La3＋ on NIH 3T3 cells was further characterized, and its impacts on the cell cycle kinetics were analyzed in detail by cell cycle arrest-and-release and pulse BrdU-labeling and chasing experiments. The results show that La3＋ promoted the proliferation of NIH 3T3 cells after 12 h and the ECs0 was 2.4 ktM after 48 h. Such effect was also confirmed by enhanced BrdU incorporation. La3＋ stimulated more cells to pass through the G1/S checkpoint into S phase, but did not change the length of cell cycle. Furthermore, La3＋-treatment increased the protein levels and nuclear localization of cyclin D 1 and c-Myc, two key regulators of G1/S checkpoint, as demonstrated by immunostaining. The pro-proliferative effects of La3＋ share striking similarity with that of Gd3＋, and provided new information regarding the cellular biological activities of lanthanides.

Effects of Panax Notoginseng Saponins on Proliferation and Differentiation in NIH3T3 Cells

Objective： To investigate the effects of Panax notoginseng saponins （PNS） on the proliferation and differentiation in NIH3T3 cells. Methods： NIH3T3 cells were treated by various concentrations of PNS 0, 0.05, 0.10, 0.20, and 0.40 g/L. The vitality and proliferation potential of cells were detected by 3-（4,5-dimethylthiazol- 2-yl）-2, 5-diphenyltetrazolium bromide （MTT） assay, the alkaline phosphatase （ALP） activity was measured by p-nitrophenyl phosphate （pNPP） assay, and the mineralization formation ability was tested for the cellular differentiation toward osteoblast, as well as the expression level of phosphorylated extrecellular signal-regulated kinasel/2（P-ERK1/2）, extracellular signal-regulated kinasel/2 （ERK1/2） protein kinase was analyzed by Western blot with total cell lysate of NIH3T3 cells treated by PNS. Results： Both MTT and pNPP assay showed that optical density （OD） values were increased in response to PNS treatment at a dose-dependent pattern. The mineralization formation ability was enhanced in PNS-treated NIH3T3 cells compared with untreated cells. Meanwhile, the expression level of P-ERK1/2 protein kinase was up-regulated in PNS-treated NIH3T3 cells, while, the expression level of ERK1/2 protein kinase revealed no obvious difference with or without PNS treated cells. Conclusion： PNS could pay a role to promote the proliferation and differentiation in NIH3T3 cells by means of up-regulation of P-ERK1/2 protein kinase.

Differentially expressed genes and signalling pathways are involved in mouse osteoblast-like MC3T3-E1 cells exposed to 17-β estradiol

Oestrogen is essential for maintaining bone mass, and it has been demonstrated to induce osteoblast proliferation and bone formation.In this study, complementary DNA（cDNA） microarrays were used to identify and study the expression of novel genes that may be involved in MC3T3-E1 cells’ response to 17-b estradiol. MC3T3-E1 cells were inoculated in minimum essential media alpha（a-MEM）cell culture supplemented with 17-b estradiol at different concentrations and for different time periods. MC3T3-E1 cells treated with1028mol？L2117-b estradiol for 5 days exhibited the highest proliferation and alkaline phosphatase（ALP） activity; thus, this group was chosen for microarray analysis. The harvested RNA was used for microarray hybridisation and subsequent real-time reverse transcription polymerase chain reaction（RT-PCR） to validate the expression levels for selected genes. The microarray results were analysed using both functional and pathway analysis. In this study, microarray analysis detected 5 403 differentially expressed genes,of which 1 996 genes were upregulated and 3 407 genes were downregulated, 1 553 different functional classifications were identified by gene ontology（GO） analysis and 53 different pathways were involved based on pathway analysis. Among the differentially expressed genes, a portion not previously reported to be associated with the osteoblast response to oestrogen was identified. These findings clearly demonstrate that the expression of genes related to osteoblast proliferation, cell differentiation, collagens and transforming growth factor beta（TGF-b）-related cytokines increases, while the expression of genes related to apoptosis and osteoclast differentiation decreases, following the exposure of MC3T3-E1 cells to a-MEM supplemented with 17-b estradiol. Microarray analysis with functional gene classification is critical for a complete understanding of complementary intracellular processes. This microarray analysis provides large-scale gene expression data that require further confirmatory studies.

Blockage of PPARδ increases the expression of inflammatory factors in 3T3-L1 cells stimulated with TNFα

Objective： To investigate the role of peroxisome proliferator-activated receptors δ （PPARδ） in inflammatory reaction and its possible mechanism in adipocyte. Methods：Lentivirus-mediated RNA interference （RNAi） was used to block the expression of PPARδ in 3T3-L1 cells. In order to induce inflammation in 3T3-L1, cells were stimulated with tumor necrosis factor-α（TNFα, 20 ng/ml） for 4 h. The expression of PPARδ, nuclear factor κB （NFκB） and C reactive protein （CRP） were determined by Western blot analysis. Results：The expression of PPARδ was reduced by 80% after RNAi. Blockage of PPARδ promoted the expression of CRP and NFκB in cells stimulated with TNFα but had no effect on normal cells. Conclusion： PPARδ is involved in inflammatory reaction in adipocyte. Blockage of PPARδ can promote the inflammation mediated by inflammatory factors and increase the expression of NFκB and CRP in 3T3-L1 cells stimulated with TNFα.

Prognostic value of T cell immunoglobulin and mucin-domain containing-3 expression in upper gastrointestinal tract tumors:A meta-analysis

BACKGROUND There is a lack of robust prognostic markers for upper gastrointestinal(GI)tract cancers,including esophageal,gastric,and esophagogastric junction cancers.T cell immunoglobulin and mucin-domain containing-3(TIM3)plays a key immunomodulatory role and is linked to the prognosis of various cancers.However,the significance of TIM3 in upper GI tract tumors is still uncertain.AIM To investigate the prognostic value of TIM3 expression in upper GI tract tumors.METHODS A literature search was conducted on the PubMed,Embase,and Web of Science databases for relevant studies published until June 2023.After screening and quality assessment,studies that met the criteria were included in the metaanalysis.Statistical methods were used for the pooled analysis to assess the association of TIM3 expression in upper GI tract tumors with the prognosis and clinicopathological parameters.The results were reported with the hazard ratio(HR)and 95%confidence interval(CI).RESULTS Nine studies involving 2556 patients with upper GI tract cancer were included.High TIM3 expression was associated with a worse prognosis in upper GI tract cancer(HR:1.17,95%CI:1.01-1.36).Positive expression of TIM3 in gastric cancer was correlated with the T and N stage,but the difference was not statistically significant.However,TIM3 overexpression was significantly correlated with the TNM stage(odds ratio:1.21,95%CI:0.63-2.33;P<0.05).TIM3 expression showed no association with the other clinicopathological parameters.CONCLUSION High expression of TIM3 in the upper GI tract cancer is associated with a worse prognosis and advanced T or N stages,indicating its potential value as a prognostic biomarker.These findings may provide a basis for the personalized treatment of upper GI tract cancers.

血清TBil、WBC及FT3对急性心肌梗死术后全因死亡的预测价值

目的:探究血清总胆红素(TBil)、白细胞(WBC)及游离T3(FT3)对急性心肌梗死(AMI)术后全因死亡的预测价值。方法:选取2018年1月至2020年6月医院收治的88例AMI患者,根据患者术后30 d内存活情况分为生存组(n=65)与病死组(n=23),另选取同期在医院体检的健康者50例为对照组。比较三组血清TBil、WBC及FT3水平,采用Spearman相关分析血清TBil、WBC及FT3水平与AMI患者术后30 d死亡的相关性,COX回归模型单因素和多因素分析AMI患者术后全因死亡影响因素,绘制血清TBil、WBC及FT3水平不同的患者Kaplan-Meier生存曲线,受试者工作特征曲线(ROC)分析血清TBil、WBC及FT3水平预测AMI患者术后30 d死亡的价值。结果:生存组和病死组血清TBil、FT3水平较对照组低(P<0.05),WBC水平较对照组高(P<0.05);病死组血清TBil、FT3水平较生存组低(P<0.05),WBC水平较生存组高(P<0.05);相关性分析显示,血清TBil及FT3水平与AMI患者术后30 d死亡呈负相关(P<0.05),WBC水平与AMI患者术后30 d死亡呈正相关(P<0.05);COX回归模型显示,血清TBil及FT3水平下降,WBC水平升高是AMI患者术后30 d死亡的危险因素(P<0.05);ROC分析显示,当TBil<13.91μmol/L、FT3<11.43 pmol/L、WBC>12.30×109/L时,预测AMI患者术后30 d死亡的AUC为0.945,敏感性为91.30%,特异性为96.90%;Kaplan-Meier分析显示,患者TBil<13.91μmol/L、FT3<11.43 pmol/L或WBC>12.30×109/L时,其术后30 d死亡率显著高于TBil≥13.91μmol/L、FT3≥11.43 pmol/L或WBC≤12.30×109/L时(P<0.05)。结论:血清TBil、WBC及FT3是AMI术后全因死亡的有效预测指标。

Combined TIM-3 and PD-1 blockade restrains hepatocellular carcinoma development by facilitating CD4+ and CD8+T cellmediated antitumor immune responses

BACKGROUND Immune checkpoint inhibitors(ICIs)targeting programmed cell death protein 1(PD-1)and T cell immunoglobulin and mucin domain-containing protein 3(TIM-3)are beneficial to the resumption of anti-tumor immunity response and hold extreme potential as efficient therapies for certain malignancies.However,ICIs with a single target exhibit poor overall response rate in hepatocellular carcinoma(HCC)patients due to the complex pathological mechanisms of HCC.AIM To investigate the effects of combined TIM-3 and PD-1 blockade on tumor development in an HCC mouse model,aiming to identify more effective immunotherapies and provide more treatment options for HCC patients.METHODS The levels of PD-1 and TIM-3 on CD4+and CD8+T cells from tumor tissues,ascites,and matched adjacent tissues from HCC patients were determined with flow cytometry.An HCC xenograft mouse model was established and treated with anti-TIM-3 monoclonal antibody(mAb)and/or anti-PD-1 mAb.Tumor growth in each group was measured.Hematoxylin and eosin staining and immunohistochemical staining were used to evaluate T cell infiltration in tumors.The percentage of CD4+and CD8+T cells in tissue samples from mice was tested with flow cytometry.The percentages of PD-1+CD8+,TIM-3+CD8+,and PD-1+TIM-3+CD8+T cells was accessed by flow cytometry.The levels of the cytokines including tumor necrosis factor alpha(TNF-α),interferon-γ(IFN-γ),interleukin(IL)-6,and IL-10 in tumor tissues were gauged with enzyme-linked immunosorbent assay kits.RESULTS We confirmed that PD-1 and TIM-3 expression was substantially upregulated in CD4+and CD8+T cells isolated from tumor tissues and ascites of HCC patients.TIM-3 mAb and PD-1 mAb treatment both reduced tumor volume and weight,while combined blockade had more substantial anti-tumor effects than individual treatment.Then we showed that combined therapy increased T cell infiltration into tumor tissues,and downregulated PD-1 and TIM-3 expression on CD8+T cells in tumor tissues.Moreover,combined treatment facilitated the production of T cell effector cytokines TNF-α and IFN-γ,and reduced the production of immunosuppressive cytokines IL-10 and IL-6 in tumor tissues.Thus,we implicated that combined blockade could ameliorate T cell exhaustion in HCC mouse model.CONCLUSION Combined TIM-3 and PD-1 blockade restrains HCC development by facilitating CD4+ and CD8+T cell-mediated antitumor immune responses.

HSV-tk/GCV系统对NIH3 T3细胞的体外杀伤作用研究

目的 研究HSV tk/GCV系统对NIH3T3细胞系的杀伤作用 ,为与成纤维细胞增殖有关的皮肤病基因治疗提供体外实验依据。方法 应用携带HSV tk基因的重组质粒pPNT tk通过磷酸钙转染传代培养的NIH3T3细胞 ,并经G418筛选 ,获得抗药性细胞集落 ,利用MTT法检测不同浓度GCV对NIH 3T3细胞的杀伤作用。结果 GCV对NIH3T3 /tk细胞有明显的细胞毒性作用 ,当GCV浓度为 10 .0 μmol/L时 ,NIN3T3 /tk细胞的生存抑制率已高达 95 %以上。而在同样药物浓度条件下 ,未转染的对照NIH 3T3细胞的生存抑制率为 11.9% ,与空白对照组相比较 ,差异无显著性。结论 HSV tk/GCV系统对NIH3T3细胞有很好的抑制作用 ,转染后细胞较之未转染细胞对前体药物更昔洛韦的敏感度显著增加 ,且呈剂量依赖性。

肥胖相关新基因NYGGF4对3T3-L1脂肪前体细胞的增殖调节作用

目的观察NYGGF4基因过表达对3T3-L1脂肪前体细胞增殖的影响,探讨该基因在肥胖发生发展中的作用。方法采用反转录聚合酶链反应(RT-PCR)法扩增NYGGF4开放阅读框(ORF)的全长,通过双酶切连接法构建NYGGF4-pcDNA3.1真核表达载体。采用脂体法转染3T3-L1前体脂肪细胞,以pcDNA3.1空载和未转染细胞为对照。遗传霉素(G418)压力筛选稳定转染细胞株,PCR鉴定转染细胞的NYGGF4的mRNA水平。采用四甲基偶氮唑蓝(MTT)检测稳定转染细胞株连续7 d的生长状态,以转染空载和未转染正常3T3-L1为对照,绘制生长曲线。采用SPSS 10.0软件进行统计学分析。结果1.稳定转染细胞株有NYGGF4基因的表达,而pcDNA3.1空载未见人源性NYGGF4的表达;2.转染NYGGF4基因的3T3-L1细胞增殖速度明显较未转染和转染空载的3T3-L1细胞加快。结论新基因NYGGF4可明显促进3T3-L1脂肪前体细胞的增殖,可能影响肥胖的发生发展。

Killing effect of TNF-related apoptosis inducing ligand regulated by tetracycline on gastric cancer cell line NCI-N87

AIM: To clone the cDNA fragment of human TRAIL (TNF-related apoptosis inducing ligand) into a tetracycline-regulated gene expression system, the RevTet-On system, transduce expression vectors into a gastric carcinoma cell line-NCI-N87 and examine the effects of controlled expression of TRAIL in vitro on the gastric carcinoma cells. METHODS: The full-length cDNA of TRAIL was inserted into a vector under the control of the tetracycline-responsive element (TRE) to obtain the plasmid pRevTRE-TRAIL, which was transfected into a packaging cell line PT67. In addition, vector pRev-Tet On and pRevTRE were also transfected into PT67 separately. After hygromycin and G418 selection, the viral titer was determined. The medium containing retroviral vectors was collected and used to transduce a gastric carcinoma cell line NCI-N87. The resulting cell line NCI-N87-Tet On TRE-TRAIL and a control cell line, NCI-N87 Tet On-TRE, were established. TRAIL expression in the cell line was induced by incubating cells with doxycycline (Dox), which is a tetracycline analogue. The killing effect on gastric carcinoma cells was analyzed after induction. RESULTS: The recombinant plasmid pRev-TRE-TRAIL was constructed. After hygromycin or G418 selection, the producer cell lines PT67-TRE, PT67-TRE-TRAIL and PT67-Tet On were obtained,with titers of about 10(8)CFU.L(-1). By transducing NCI-N87 cells with retroviral vectors from these cell lines, stable cell lines NCI-N87-Tet-On TRE-TRAIL (NN3T) and control cell line NCI-N87-Tet-On-TRE (NN2T) were established. The growth curves of the selected cell lines were the same with the wild type NCI-N87. When Dox was added, cell death was obvious in the test groups (29%-77%), whereas no difference was observed in control and wild type cell lines. With the addition of a medium from the test group, human leukemia cell line Jurkat was activated till death (83%), indicating the secretion of active TRAIL proteins from the test cells to the medium. CONCLUSION: With the use of the RevTet-On system, a regulated expression system for TRAIL was constructed. Using this system, the selected killing effect of TRAIL on gastric carcinoma cell line NCI-N87 could be observed.

Cav3.2 channel regulates cerebral ischemia/reperfusion injury:a promising target for intervention

Calcium influx into neurons triggers neuronal death during cerebral ischemia/reperfusion injury.Various calcium channels are involved in cerebral ischemia/reperfusion injury.Cav3.2 channel is a main subtype of T-type calcium channels.T-type calcium channel blockers,such as pimozide and mibefradil,have been shown to prevent cerebral ischemia/reperfusion injury-induced brain injury.However,the role of Cav3.2 channels in cerebral ischemia/reperfusion injury remains unclear.Here,in vitro and in vivo models of cerebral ischemia/reperfusion injury were established using middle cerebral artery occlusion in mice and high glucose hypoxia/reoxygenation exposure in primary hippocampal neurons.The results showed that Cav3.2 expression was significantly upregulated in injured hippocampal tissue and primary hippocampal neurons.We further established a Cav3.2 gene-knockout mouse model of cerebral ischemia/reperfusion injury.Cav3.2 knockout markedly reduced infarct volume and brain water content,and alleviated neurological dysfunction after cerebral ischemia/reperfusion injury.Additionally,Cav3.2 knockout attenuated cerebral ischemia/reperfusion injury-induced oxidative stress,inflammatory response,and neuronal apoptosis.In the hippocampus of Cav3.2-knockout mice,calcineurin overexpression offset the beneficial effect of Cav3.2 knockout after cerebral ischemia/reperfusion injury.These findings suggest that the neuroprotective function of Cav3.2 knockout is mediated by calcineurin/nuclear factor of activated T cells 3 signaling.Findings from this study suggest that Cav3.2 could be a promising target for treatment of cerebral ischemia/reperfusion injury.

含枸杞多糖血清对MC3T3-E1成骨细胞增殖、分化和矿化的影响

目的研究含枸杞多糖血清对MC3T3-E1成骨细胞细胞增殖、分化和矿化的影响。方法含枸杞多糖血清分别加入MC3T3-E1成骨细胞培养液中,使其终浓度为5%、10%、20%3种体积浓度,通过MTT法,碱性磷酸酶活性测定,骨钙素检测和Von kossa矿化染色法观察含枸杞多糖血清的促细胞增殖、分化、矿化作用。结果含枸杞多糖血清在5%、10%浓度促进MC3T3-E1成骨细胞增殖,差异有统计学意义(P<0.05);10%、20%浓度提高MC3T3-E1成骨细胞内碱性磷酸酶的活性,差异有统计学意义(P<0.01)。含枸杞多糖血清在20%浓度培养7及11 d时能明显促进MC3T3-E1成骨细胞骨钙素合成和分泌,20%浓度培养18 d时MC3T3-E1成骨细胞的矿化结节数目增多,差异有统计学意义(P<0.01)。结论含枸杞多糖血清可以促进MC3T3-E1成骨细胞增殖、分化和矿化能力。

热休克蛋白70在3T3细胞创伤愈合中的作用

目的 :探讨热休克蛋白 70 (HSP70 )在细胞创伤后增殖中的作用。方法 :采用细胞机械创伤模型 ,检测创伤后 48h时热处理细胞及非热处理细胞的增殖活性 ,并用免疫细胞化学的方法检测两组细胞生长过程中HSP70的表达。结果 :非热处理组细胞在增殖期表达 HSP70。热处理可诱导 HSP70的表达 ,热处理组创伤后细胞的增殖活性明显高于非热处理组。结论 :HSP70参与细胞增殖过程 ,热处理引起的细胞增殖活性升高可能与 HSP70的功能有关。

PRNP基因在3T3-L1脂肪前体细胞分化过程中的表达及肿瘤坏死因子-α对其调节作用

目的探讨3T3-L1脂肪前体细胞诱导分化过程中PRNP基因表达水平的变化及TNF-α对其调节作用。方法体外培养3T3-L1前体脂肪细胞,胰岛素加地塞米松加1-甲基-3-异丁基黄嘌呤（MDI）方案诱导3T3-L1细胞分化成熟,并收集分化前、分化0～10 d各时段细胞,采用RT-PCR技术检测诱导分化不同时段3T3-L1细胞PRNP基因表达水平;同时在成功诱导3T3-L1细胞分化成熟的基础上,应用不同水平TNF-α（0.1、1.0、10.0μg/L）干预分化后的成熟脂肪细胞（第10天）,收集TNF-α刺激前（0 h）及刺激后0.5、2.0、6.0、12.0、24.0 h的脂肪细胞,通过RT-PCR测定TNF-α干预前后不同时间点脂肪细胞中PRNP基因表达水平。采用Excel软件进行统计学分析。结果1.PRNP基因低表达于3T3-L1脂肪前体细胞中,随细胞分化成熟该基因表达水平逐渐上调,至分化第10天其表达水平最高。PRNP基因表达水平除在诱导分化前（第-1天）至第4天、第2～5天、第6～10天时段内无显著性差异外（Pa〉0.05）,其余各时段间表达水平均有显著性差异（Pa〈0.05）;2.在分化前的3T3-L1脂肪细胞和成熟脂肪细胞中,不同水平TNF-α（0.1、1.0、10.0μg/L）均能在短时间内明显抑制PRNP基因mRNA的表达,且呈时间依赖性。结论PRNP基因可能参与3T3-L1脂肪细胞分化及脂质积聚过程;不同水平重组TNF-α对成熟脂肪细胞的PRNP基因表达具有抑制作用,其抑制效应总体趋势上呈时间依赖性。