Protective effect of erythropoietin against 1-methyl-4-phenylpyridinium-induced neurodegenaration in PC12 cells

Objective The neuroprotective effect of erythropoietin （EPO） against 1-methyl-4-phenylpyridinium （MPP^＋）- induced oxidative stress in cultured PC12 cells, as well as the underlying mechanism, were investigated. Methods PC12 ceils impaired by MPP^＋ were used as the cell model of Parkinson＇s disease. Methyl thiazolyl tetrazolium （MTT） was used to assay the viability of the PC12 cells exposed to gradient concentrations of EPO, and the terminal deoxynucleotidyl transferase dUTP nick end labelling （TUNEL） assay was used to analyze the apoptosis ratio of PC 12 cells. The expression of Bcl-2 and Bax in PC 12 cells were examined by Western blot, and the reactive oxygen species （ROS）, the mitochondrial transmembrane potential and the activity of caspase-3 in each group were detected by spectrofluorometer. Results Treatment of PC12 cells with MPP^＋ caused the loss of cell viability, which may be associated with the elevation in apoptotic rate, the formation of ROS and the disruption of mitochondrial transmembrane potential. It was also shown that MPP＋ significantly induced the upregulation of Bax/Bcl-2 ratio and the activation of caspase-3. In contrast, EPO significantly reversed these responses and had the maximum protective effect at 1 U/mL. Conclusion The inhibitive effect of EPO on the MPP^＋ -induced cytotoxicity may be ascribed to its anti-oxidative property and anti-apoptotic activity, and EPO may provide a useful therapeutic strategy for treatment of neurodegenerative diseases such as Parkinson＇s disease.

DNA hypermethylation of COL4A1 in ultraviolet-Binduced age-related cataract models in vitro and in vivo

AIM:To explore the DNA methylation of COL4A1 in ultraviolet-B(UVB)-induced age-related cataract(ARC)models in vitro and in vivo.METHODS:Human lens epithelium B3(HLEB3)cells and Sprague Dawley rats were exposure to UVB respectively.The MTT assay was utilized to evaluate cell proliferation.Flow cytometry was employed for analysis of cell apoptosis and cell cycle.COL4A1 expression in HLEB3 cells and anterior lens capsules were assessed using Western blot and reverse transcription-polymerase chain reaction(RTPCR).The localization of COL4A1 in HLEB3 cells was determined by immunofluorescence.The methylation status of CpG islands located in COL4A1 promoter was verified using bisulfite-sequencing PCR(BSP).DNMTs and TETs mRNA levels was examined by RT-PCR.RESULTS:UVB exposure decreased HLEB3 cells proliferation,while increased the apoptosis rate and cells were arrested in G0/G1 phase.COL4A1 expression was markedly inhibited in UVB treated cells compared to the controls.Hypermethylation status was detected in the CpG islands within COL4A1 promoter in HLEB3 cells subjected to UVB exposure.Expressions of DNMTs including DNMT1/2/3 were elevated in UVB treated HLEB3 cells compared to that in the controls,while expressions of TETs including TET1/2/3 showed the opposite trend.Results from the UVB treated rat model further confirmed the decreased expression of COL4A1,hypermethylation status of the CpG islands at promoter of COL4A1 and abnormal expression of DNMT1/2/3 and TET1/2/in UVB exposure group.CONCLUSION:DNA hypermethylation of COL4A1 promoter CpG islands is correlated with decreased COL4A1 expression in UVB induced HLEB3 cells and anterior lens capsules of rats.

外周血CD4^(+)PD-1^(+)Tcells及CD4^(+)T淋巴细胞ATP含量与复发性卵巢癌疗效的相关性分析

目的 探讨外周血CD4^(+)程序性细胞死亡受体-1(PD-1)^(+)T cells及CD4^(+)T淋巴细胞三磷酸腺苷(ATP)含量与复发性卵巢癌疗效的相关性。方法 选取30例复发性卵巢癌患者为复发组,30例未复发卵巢癌患者为非复发组;另选取30名同期体检健康者作为对照组。评估外周血CD4^(+)PD-1^(+)T cells及CD4^(+)T淋巴细胞ATP含量与复发性卵巢癌疗效的相关性。结果 复发组和非复发组的CD4^(+)PD-1^(+)T cells较对照组明显升高(P<0.05)。复发组和非复发组的CD4^(+)T淋巴细胞ATP含量较对照组明显降低(P<0.05)。复发组治疗后CD4^(+)PD-1^(+)Tcells显著低于治疗前(P<0.05),治疗后CD4^(+)T淋巴细胞ATP含量显著高于治疗前(P<0.05)。CD4^(+)PD-1^(+)T cells与复发性卵巢癌疗效成负相关(r=-0.393,P=0.039),CD4^(+)T淋巴细胞ATP含量与复发性卵巢癌疗效成正相关(r=0.449,P=0.031)。结论 复发性卵巢癌患者外周血CD4^(+)PD-1^(+)T cells及CD4^(+)T淋巴细胞ATP含量与疗效密切相关。

Ferrostatin-1 protects HT-22 cells from oxidative toxicity

Ferroptosis is a type of programmed cell death dependent on iron.It is different from other forms of cell death such as apoptosis,classic necrosis and autophagy.Ferroptosis is involved in many neurodegenerative diseases.The role of ferroptosis in glutamate-induced neuronal toxicity is not fully understood.To test its toxicity,glutamate(1.25–20 mM)was applied to HT-22 cells for 12 to 48 hours.The optimal experimental conditions occurred at 12 hours after incubation with 5 mM glutamate.Cells were cultured with 3–12μM ferrostatin-1,an inhibitor of ferroptosis,for 12 hours before exposure to glutamate.The cell viability was detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.Autophagy was determined by monodansylcadaverine staining and apoptosis by caspase 3 activity.Damage to cell structures was observed under light and by transmission electron microscopy.The release of lactate dehydrogenase was detected by the commercial kit.Reactive oxygen species were measured by flow cytometry.Glutathione peroxidase activity,superoxide dismutase activity and malondialdehyde level were detected by the appropriate commercial kit.Prostaglandin peroxidase synthase 2 and glutathione peroxidase 4 gene expression was detected by real-time quantitative polymerase chain reaction.Glutathione peroxidase 4 and nuclear factor erythroid-derived-like 2 protein expression was detected by western blot analysis.Results showed that ferrostatin-1 can significantly counter the effects of glutamate on HT-22 cells,improving the survival rate,reducing the release of lactate dehydrogenase and reducing the damage to mitochondrial ultrastructure.However,it did not affect the caspase-3 expression and monodansylcadaverine-positive staining in glutamate-injured HT-22 cells.Ferrostatin-1 reduced the levels of reactive oxygen species and malondialdehyde and enhanced superoxide dismutase activity.It decreased gene expression of prostaglandin peroxidase synthase 2 and increased gene expression of glutathione peroxidase 4 and protein expressions of glutathione peroxidase 4 and nuclear factor(erythroid-derived)-like 2 in glutamate-injured HT-22 cells.Treatment of cultured cells with the apoptosis inhibitor Z-Val-Ala-Asp(OMe)-fluoromethyl ketone(2–8μM),autophagy inhibitor 3-methyladenine(100–400μM)or necrosis inhibitor necrostatin-1(10–40μM)had no effect on glutamate induced cell damage.However,the iron chelator deferoxamine mesylate salt inhibited glutamate induced cell death.Thus,the results suggested that ferroptosis is caused by glutamate-induced toxicity and that ferrostatin-1 protects HT-22 cells from glutamate-induced oxidative toxicity by inhibiting the oxidative stress.

老年血管性痴呆患者血清ANGPTL4和sTLT-1水平表达与其认知功能及预后的相关性研究

目的 探讨老年血管性痴呆(vascular dementia, VD)患者血清血管生成素样蛋白4(angiopoietin-like protein 4,ANGPTL4)、可溶性骨髓细胞样转录因子-1(soluble bone marrow cell-like transcription factor-1,sTLT-1)水平表达与其认知功能和预后的相关性研究。方法 选取2020年6月~2022年6月在河北燕达医院收治的92例老年血管性痴呆患者作为研究组,根据简易精神状态量表(minimum mental state examination,MMSE)评分分为轻度组(n=30)、中度组(n=36)和重度组(n=26),另选取同期健康体检者92例作为对照组。根据患者预后认知功能障碍情况分为Ⅰ~Ⅱ级和Ⅲ级;采用ELISA方法检测各组血清ANGPTL4和sTLT-1水平,采用Pearson和Spearman法分析血清ANGPTL4,sTLT-1与MOCA评分的相关性;采用Logistic回归分析老年血管性痴呆患者预后分级为Ⅲ级的影响因素;绘制受试者工作特征(receiver operating characteristic,ROC)曲线分析血清ANGPTL4和sTLT-1水平对老年血管性痴呆患者预后分级为Ⅲ级的预测价值。结果 研究组血清ANGPTL4(987.57±53.25 pg/ml)水平显著低于对照组(1 108.35±62.13 pg/ml),血清sTLT-1(68.01±5.15 pg/ml)水平显著高于对照组(50.12±4.57 pg/ml),差异具有统计学意义(t=14.158,24.922,均P <0.05)。轻度、中度和重度组血清ANGPTL4水平和MOCA评分依次降低(F=33.495,66.617),血清sTLT-1水平依次升高(F=66.718),差异具有统计学意义(均P <0.05)。Pearson法分析显示,血清ANGPTL4与sTLT-1呈负相关(r=-0.621,P <0.05),Spearman法分析显示,血清ANGPTL4与MoCA评分呈正相关(r=0.545,P <0.05),sTLT-1水平与MoCA评分呈负相关(r=-0.557,P <0.05)。Ⅲ级预后患者血清ANGPTL4(953.45±51.16 pg/ml)水平显著低于Ⅰ~Ⅱ级(1 005.76±54.27 pg/mL),血清sTLT-1(73.14±5.40 pg/ml)水平显著高于Ⅰ~Ⅱ级(65.28±5.02pg/ml),差异具有统计学意义(t=4.490,6.967,均P <0.05)。Logistic回归分析得知,ANGPTL4低表达[OR(95%CI):5.089(1.833~14.129)],sTLT-1高表达[OR(95%CI):4.258(1.739~10.428)]均为影响老年血管性痴呆患者预后分级为Ⅲ级的危险因素(P <0.05)。根据ROC曲线得知,二者联合预测老年血管性痴呆患者预后分级为Ⅲ级优于ANGPTL4和sTLT-1各自单独预测(Z=2.135,3.268,均P <0.05)。结论 老年血管性痴呆患者血清ANGPTL4水平显著降低,sTLT-1水平显著升高,ANGPTL4和sTLT-1与认知功能和预后密切相关。

Ribavirin and IFN-α combination therapy induces CD4+ T-cell proliferation and Th1 cytokine secretion in patients with chronic hepatitis B

AIM: To investigate the anti-viral mechanism of combination therapy of interferon (IFN)-α and ribavirin in patients with chronic hepatitis B. METHODS: Twenty patients were assigned to receive either IFN-α plus ribavirin (group A,n = 14) or no treatment as a control (group B,n = 6). Patients were analyzed for T-cell proliferative responses specific for hepatitis B virus (HBV)-antigen and cytokine production by peripheral blood mononuclear cells (PBMCs). RESULTS: Combination therapy induced HBV-antigen specific CD4+ T-cell proliferative responses in four patients (28.6%). Production of high levels of HBV-specific IFN-γ,tumor necrosis factor (TNF)-α,interleukin (IL)-12 by PBMCs was found in five patients (35.7%),who showed significantly lower HBV DNA levels in serum at 12 mo after treatment ended (P = 0.038) and at 24 mo of follow-up (P = 0.004) than those without high levels of cytokine production. CONCLUSION: HBV-antigen specific CD4+ T cells may directly control HBV replication and secretion of anti-viral T helper 1 (Th1) cytokines by PBMCs during combination therapy of chronic hepatitis B with ribavirin and IFN-α.

All-transRetinoic Acid Regulates Th1/Th2 Balance in CD4+T cells When GATA-3 is Deficient

The essential effect of vitamin A on immune function occurs through various mechanisms including direct effect on ThloTh2 balance modulation. However, it is unclear whether or not vitamin A can regulate Thl-Th2 balance under a strong Thl-polarizing condition. Therefore, the purpose of our study was to examine the effect of vitamin A metabolite allotrans retinoic acid （ATRA） on ThloTh2 differentiation in CD4~ T cells under GATA-3 deficiency, which can induce Thl-polarizing condition. In the present study, GATA-3 deficiency T cells were induced by siRNA and checked by real-time quantitative PCR and western blot. GATA-3 deficiency CD4＋ T cells and normal CD4＋ T were treated for 48 h with or without ATRA.

Effect of insulin on 1-methyl-4-phenylpyridinium ion-induced apoptosis of PC12 cells

BACKGROUND： Insulin receptor （IR） expression in the substantia nigra of patients with Parkinson disease （PD） is not only significantly lower than that in the substantia nigra of normal persons of the same age, but also significantly lower than that in other regions in brain of himself/herself. It suggests that the abnormal effect of insulin receptor-mediated insulin, as a neurotrophic factor, is very possibly related to the loss of dopaminergic neurons in the substantia nigra and striatum in patients with Parkinson disease. OBJECTIVE ： TO observe the interventional effect of insulin on 1-methyl-4-phenylpyridinium ion （MPP^＋）-induced apoptosis of PC12. DESIGN： Controlled observation SETTINGS： Department of Neurology, Beijing China-Japan Friendship Hospital; Department of Neurology Huashan Hospital Affiliated to Fudan University. MATERIALS： PC12 cells were provided by the Cell Bank, Shanghai Institute of Cell Biology, Chinese Academy of Science. MPP^＋, MTT, HOECHST 33258 （Invitrogen Life Technologies）, reverse transcription-polymerase chain reaction （RT-PCR） reagent （Takara Shuzo Co., Ltd.）, flow cytometer （Bacton Dickionson, San Jose, CA）, enzyme labelling instrument （Bio-Tek, Winooski, VT） and PCR circulation instrument （Takara Shuzo Co., Ltd） were used in this study. METHODS ： This study was carried out in the Department of Neurology, Huashan Hospital Affiliated to Fudan University during June 2003 to August 2004. （1） Cell culture and experimental grouping： PC12 cells were cultured according to the method from Peng et al, then were randomized into 3 groups; blank control group, MPP^＋ group and insulin group. （2） Detection of relative survival rate of cells： The relative survival rate of cells at different MPP^＋ final concentrations （0, 50, 100, 200, 300, 1 000 μmol/L） and at different culture time （0, 4, 8, 12, 18, 24 hours） in the 300 Fmol/L MPP^＋ group and different concentrations of insulin （0, 15, 50, 100 nmol/L） in the insulin group was detected with MTT method according to the method from Hansen et al. （3） Observation of cell apoptosis： After stained by HOECHST 33258, the apoptotic cells were observed under the fluorescence miscroscope with the method from Chen et al. （4） Dection of apoptotic rate of cells： Apoptotic rate of cells was detected with flow cytometry according to the method from Zhang et al. （5） The expression of tyrosine hydroxylase （TH） mRNA in PC12 cells was detected with RT-PCR methods according to the modified method from Peng et al. MAIN OUTCOME MEASURES ： Comparison of relative survival rate, apoptosis rate, the expression of IR mRNA and TH mRNA and cell apoptosis. RESULTS： （1） After 12-hour incubation of 100, 200, 300 and 1 000 μmol/L MPP^＋, the relative survival rate of PC12 cells was （72.88±2.91）%, （60.64±0.81）%, （54.56±0.76）% and （16.89±2.83）%, respectively, which was significantly lower than that of blank control group （100%, P 〈 0.05）; After 12, 18 and 24-hour incubation, the relative survival rate of PC12 cells was （54.56±0.76）%, （42.43±0.16）% and （23.56±0.17）% respectively, which was significantly lower than that of blank control group （100%, P〈 0.05）; When 15, 50 and 100 nmol/L insulin was pre-added to cells, the relative survival rate was （70.10±0.16）%, （78.01 ±2.43）% and （83.55±1.43）%, respectively, which was significantly higher than MPP^＋ alone [（54.56±0.76）%, P 〈 0.05]. （2） Appototic bodies were rarely seen in the blank control group, but densely gathered in the MPP^＋ group and were significantly decreased in the insulin group. （3） Apoptosis rate of PC12 cells in the MPP^＋ group was significantly higher than that in the blank control group [（36.56±0.89）% vs. （2.34±0.23）%, P〈 0.05], and that in the 15, 50, 100 nmol/L insulin group [（30.01±0.04）%, （24.23±0.37）%, （20.01 ±1.01）%, respectivelyl was significantly lower than that in MPP^＋ group （P 〈 0.05）. （4） The TH mRNA expression in PC12 cells in MPP^＋ group was significantly lower than that in blank control group; The expression of TH mRNA in insulin group was gradually increased in an insulin dose-dependent manner. There were no significant changes in the expression of IR mRNA under different experimental conditions. CONCLUSION： Insulin can resist MPP^＋-induced apoptosis of PC12 cells, lessen the damage of PC12 cells, but does not change the gene expression of target cell insulin receptor.

Lysine-specific demethylase 1 inhibitor rescues the osteogenic ability of mesenchymal stem cells under osteoporotic conditions by modulating H3K4 methylation

Bone tissue engineering may be hindered by underlying osteoporosis because of a decreased osteogenic ability of autologous seed cells and an unfavorably changed microenvironment in these patients. Epigenetic regulation plays an important role in the developmental origins of osteoporosis; however, few studies have investigated the potential of epigenetic therapy to improve or rescue the osteogenic ability of bone marrow mesenchymal stem cells(BMMSCs) under osteoporotic conditions. Here, we investigated pargyline, an inhibitor of lysine-specific demethylase 1(LSD1), which mainly catalyzes the demethylation of the di- and mono-methylation of H3K4. We demonstrated that 1.5 mmol·Lpargyline was the optimal concentration for the osteogenic differentiation of human BMMSCs. Pargyline rescued the osteogenic differentiation ability of mouse BMMSCs under osteoporotic conditions by enhancing the dimethylation level of H3K4 at the promoter regions of osteogenesis-related genes. Moreover, pargyline partially rescued or prevented the osteoporotic conditions in aged or ovariectomized mouse models, respectively. By introducing the concept of epigenetic therapy into the field of osteoporosis, this study demonstrated that LSD1 inhibitors could improve the clinical practice of MSC-based bone tissue engineering and proposes their novel use to treat osteoporosis.

Transplantation Expression of 4-1BB molecule on peripheral blood T cells in liver transplanted patients and its clinical implication

OBJECTIVE: To investigate the gene expression of 4-1BB in peripheral blood mononuclear cells (PBMCs) and its possible significance in clinical liver transplantation. METHODS: Reverse transcription-polymerase chain reaction (RT-PCR) was used to determine the gene expression of 4-1BB in PBMCs from 22 patients receiving liver transplantation, 13 patients with primary liver carcinoma (PLC), and 12 healthy controls. To determine whether 4-1BB molecule is also expressed on the surface of CD4^+ and CD8^+ T cell, flow cytometry was used to analyse the phenotype of T cell subsets from the blood of liver transplantation patients. RESULTS: 4-1BB mRNA was detected in PBMCs from stable survivors after liver transplantation, but almost not deteeted in PBMCs from PLC patients and healthy controls. Meanwhile, 4-1BB was almost not expressed on the surface of CD4^+ and CD8^+ T cells in healthy controls and PLC patients. A low level of 4-1BB expression, however, was found on the surface of CD4^+ and CD8^+ T cells from the stable survivors after liver transplantation. CONCLUSIONS: This study demonstrates that although patients are stable after liver transplantation, effector T-cells can also be activated through the signal of 4-1BB molecule and persistent irmmune response to grafts. Blockage of 4-1BB/4-1BBL pathway may benefitially reduce the clinical dosage of immunosuppressive agents and prolong the survival of grafts.

TGF-β1 treated murine dendritic cells are maturation resistant and down-regulate Toll-like receptor 4 expression

Objective: To explore the effects of transforming growth factor (51 (TGF-β1) on dendritic cells (DC). Methods: Murine bone marrow cells were cultured with GM-CSF and TGF-β1 to develop TGF-β1-treated DC (TGFβ-DC). Then they were stimulated by lipopolysaccharide (LPS). Their phenotypes were assessed by flow cytometry (FCM). The allogeneic stimulating capacity of DC was measured by mixed lymphocyte reaction (MLR) using BrdU ELISA method and IL-12p70 protein was detected by ELISA. The expression of Toll-like receptor 4 (TLR4) was analyzed by semi quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and FCM. Results: Compared to immature DC (imDC) cultured by GM-CSF alone, the TGFβ-DC express lower CD80, CD86,I-Ab and CD40. The TGFβ-DC were resistant to maturation with LPS. Maturation resistance was evident from a failure to up-regulate co-stimulatory molecules (CMs), to stimulate larger T cells proliferation and to enhance secretion of IL-12p70. We also found that TGF-β1 could down-regulate TLR4 expression on TGFβ-DC. Conclusion: TGFβ-DC are resistant to maturation stimulus (LPS) and might have some correlation with the down-modulation of TLR4 expression.

Minocycline protects the apoptosis of PC12 cells induced by 1-methyl-4-phenylpyridinium

Objective： To explore the protective effect of minocycline on the apoptosis of cellular parkinsonism models induced by MPP^＋ . Methods： Using PC12 cells as the apoptotic model of dopaminergic neurons, MC and MPP^＋ were added into the culture medium of PC12 cells, and using MTr to assay the cell viability and metabolic state; The cells apoptosis was assayed by electrophoresis method and using flow cytometry FACS to assay the apoptosis ratio. Results： Added the MPP^＋ to get the concentration of 10μmol/L, the cellular parkinsonism model of apoptosis had been prepared. The pre-treatment of MC （ 100/μmol/L） could significantly increase the PC12 cell viability. The apoptosis ratio of MC＋MPP^＋ group was significantly lower than that of MPP^＋ group, but was still significantly higher than that of control group. Conclusion： MC may protect the cell apoptosis induced by MPP^＋ to some extent.

SPOC domain-containing protein 1 regulates the proliferation and apoptosis of human spermatogonial stem cells through adenylate kinase 4

BACKGROUND Spermatogonial stem cells(SSCs)are the origin of male spermatogenesis,which can reconstruct germ cell lineage in mice.However,the application of SSCs for male fertility restoration is hindered due to the unclear mechanisms of proliferation and self-renewal in humans.AIM To investigate the role and mechanism of SPOC domain-containing protein 1(SPOCD1)in human SSC proliferation.METHODS We analyzed publicly available human testis single-cell RNA sequencing(RNAseq)data and found that SPOCD1 is predominantly expressed in SSCs in the early developmental stages.Small interfering RNA was applied to suppress SPOCD1 expression to detect the impacts of SPOCD1 inhibition on SSC proliferation and apoptosis.Subsequently,we explored the target genes of SPOCD1 using RNA-seq and confirmed their role by restoring the expression of the target genes.In addition,we examined SPOCD1 expression in some non-obstructive azoospermia(NOA)patients to explore the correlation between SPOCD1 and NOA.RESULTS The uniform manifold approximation and projection clustering and pseudotime analysis showed that SPOCD1 was highly expressed in the early stages of SSC,and immunohistological results showed that SPOCD1 was mainly localized in glial cell line-derived neurotrophic factor family receptor alpha-1 positive SSCs.SPOCD1 knockdown significantly inhibited cell proliferation and promoted apoptosis.RNA-seq results showed that SPOCD1 knockdown significantly downregulated genes such as adenylate kinase 4(AK4).Overexpression of AK4 in SPOCD1 knockdown cells partially reversed the phenotypic changes,indicating that AK4 is a functional target gene of SPOCD1.In addition,we found a significant downregulation of SPOCD1 expression in some NOA patients,suggesting that the downregulation of SPOCD1 may be relevant for NOA.CONCLUSION Our study broadens the understanding of human SSC fate determination and may offer new theories on the etiology of male infertility.

Correlation between receptor-interacting protein 140 expression and directed differentiation of human embryonic stem cells into neural stem cells

Overexpression of receptor-interacting protein 140（RIP140） promotes neuronal differentiation of N2 a cells via extracellular regulated kinase 1/2（ERK1/2） signaling.However,involvement of RIP140 in human neural differentiation remains unclear.We found both RIP140 and ERK1/2 expression increased during neural differentiation of H1 human embryonic stem cells.Moreover,RIP140 negatively correlated with stem cell markers Oct4 and Sox2 during early stages of neural differentiation,and positively correlated with the neural stem cell marker Nestin during later stages.Thus,ERK1/2 signaling may provide the molecular mechanism by which RIP140 takes part in neural differentiation to eventually affect the number of neurons produced.

Apoptosis in immune cells induced by fission fragment ^(147)Pm

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THE ROLE OF VCAM-1/VLA-4 IN THE ACTIVATION OF ALLOGENIC T CELLS BY MURINE MACROPHAGES

This work was supported by grants from the National Natural Science Foundation of China.No. (39730420). ** To whom requests for reprints should be addressed.This is one of papers of the special issue on gene therapy research (Chin J Cancer Res Vol. 9 No. 4 December, 1997). Vascular cell adhesion molecule 1 (VCAM 1) is a member of immunoglobulin superfamily. The principal ligand for VCAM 1 is integrin α4β1/VLA 4 (very late antigen 4). It was reported that VCAM 1 was expressed on macrophages and dendritic cells, but little is known about its function on these professional antigen pre senting cells (APC). The present study was performed to investigate the expression of VCAM 1 on macrophages and the role of VCAM 1/VLA 4 in the activation of allogenic T cells by murine macrophages. We analyzed VCAM 1 expression on peritoneal macrophages and macrophage cell line J774A.1 by fluorescence activated cell sorting (FACS). Using neutralizing antibodies, we further analyzed the role of VCAM 1/VLA 4 interaction in macrophage and allogenic T cell mixed lymphocyte reaction (MLR). We found that VCAM 1 was consti tutively expressed on macrophages and its expression level was upregulated by soluble tumor associated antigen (freeze thaw lysates of FBL 3 leukemia cells) and TNF α. In MLR assays, we observed that blocking VCAM 1/VLA 4 interaction with anti VCAM 1 or anti VLA 4 mAbs caused significant inhibition of the proliferative response and IL 2 production. These results suggest that VCAM 1on macrophages not only facilitates the cell to cell contact through adhesive interaction but also plays a role in the costimulation of T cells via its interaction with VLA 4 on the T cells.

Neuroprotective effect of Eleutheroside B on 1-methyl-4-phenylpyridinium ion-induced apoptosis in PC12 cells

Apoptosis and viability of PC12 cells following 1-methyl-4-phenylpyridinium ion （MPP＋）-induced injury were monitored by flow cytometry, following Annexin V-propidium iodide double labeling, and 3-（4,5-Dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide assay, respectively. The release of lactate dehydrogenase, superoxide dismutase activity and levels of malondialdehyde were determined by UV spectrophotometry. The changes in mitochondrial membrane potential and the intracellular concentration of calcium were determined by flow cytometry, and the activity of caspase-3 was monitored by western blot. According to cell viability and apoptosis studies, MPP＋-induced apoptosis in PC12 cells was inhibited in the presence of 10 tJg/mL of Eleutheroside B Our results indicate that the neuroprotective effect of Eleutheroside B, following MPP＋-induced apoptosis in PC12 cells, involves increasing the anti-oxidative stress capacity of cells, maintaining the high-energy state of mitochondrial membrane potential, reducing intracellular calcium concentration and inhibiting caspase-3 activity.

Binding of HIV-1 virions to α_4β_7 expressing cells and impact of antagonizing α_4β_7 on HIV-1 infection of primary CD4^+ T cells

HIV-1 envelope glycoprotein is reported to interact with α4β7, an integrin mediating the homing of lymphocytes to gut-associated lymphoid tissue, but the significance of α4β7 in HIV-1 infection remains controversial. Here, using HIV-1 strain Ba L, the gp120 of which was previously shown to be capable of interacting with α4β7, we demonstrated that α4β7 can mediate the binding of whole HIV-1 virions to α4β7-expressing transfectants. We further constructed a cell line stably expressing α4β7 and confirmed the α4β7-mediated HIV-1 binding. In primary lymphocytes with activated α4β7 expression, we also observed significant virus binding which can be inhibited by an anti-α4β7 antibody. Moreover, we investigated the impact of antagonizing α4β7 on HIV-1 infection of primary CD4+ T cells. In α4β7-activated CD4+ T cells, both anti-α4β7 antibodies and introduction of shorthairpin RNAs specifically targeting α4β7 resulted in a decreased HIV-1 infection. Our findings indicate that α4β7 may serve as an attachment factor at least for some HIV-1 strains. The established approach provides a promising means for the investigation of other viral strains to understand the potential roles of α4β7 in HIV-1 infection.

NH4Cl promotes apoptosis and inflammation in bovine mammary epithelial cells via the circ02771/miR-194b/TGIF1 axis

Excess ammonia(NH_(3))in the circulation of dairy animals can reduce animal health and the quality of products for human consumption.To develop effective prevention and treatment methods,it is essential to examine the molecular mechanisms through which excess NH_(3) may affect the mammary gland.The present study used bovine mammary epithelial cells(BMECs)to evaluate the effects of exogenous NH_(4)Cl on the abundance of circular RNAs(circRNAs)using high-throughput sequencing.Among the identified circRNAs,circ02771 was the most significantly upregulated by exogenous NH_(4)Cl(P<0.05),with a fold change of 4.12.The results of the apoptosis and proliferation assays,transmission electron microscopy,H&E staining,and immunohistochemistry revealed that circ02771 increased apoptosis and inflammation.A double luciferase reporter assay revealed that circ02771 targeted miR-194b,and the overexpression of circ02771(pcDNA-circ02771)reduced(P<0.05)the expression of miR-194b and led to apoptosis and inflammation.Circ02771 also enhanced the expression of transforming growth factor beta-induced factor homeobox 1(TGIF1),which is a target gene of miR-194b.Overall,this study suggests that the circ02771/miR-194b/TGIF1 axis plays a role in mediating the effects of NH_(4)Cl on BMECs.Therefore,this axis provides a novel target to help control hazards within the mammary gland from high circulating NH_(4)Cl levels.

NR4A1 enhances glycolysis in hypoxia-exposed pulmonary artery smooth muscle cells by upregulating HIF-1αexpression

Background:Pulmonary arterial hypertension(PAH)is a chronic and progressive disease that is strongly associated with dysregulation of glucose metabolism.Alterations in nuclear receptor subfamily 4 group A member 1(NR4A1)activity alter the outcome of PAH.This study aimed to investigate the effects of NR4A1 on glycolysis in PAH and its underlying mechanisms.Methods:This study included twenty healthy volunteers and twenty-three PAH patients,and plasma samples were collected from the participants.To mimic the conditions of PAH in vitro,a hypoxia-induced model of pulmonary artery smooth muscle cell(PASMC)model was established.The proliferation of PASMCs was assessed using CCK8 assays.Results:Levels of NR4A1,hypoxia-inducible factor-1α(HIF-1α),and various glycolysis-related enzymes were measured.In addition,extracellular glucose and lactate production were assessed.The interaction between NR4A1 and HIF-1αwas evaluated by co-immunoprecipitation assays.Levels of NR4A1 and HIF-1αwas increased in PAH patients,and exposure to hypoxia resulted in increased levels of NR4A1 and HIF-1αin PASMCs.NR4A1 interacted with HIF-1α.NR4A1 overexpression enhanced hypoxia-induced expression of HIF-1α,GLUT1,PKM2,HK2,and CD36,decreased glucose levels,increased lactate levels and promoted hypoxic PASMC viability.Conversely,silencing NR4A1 decreased hypoxia-induced expression of HIF-1α,GLUT1,PKM2,HK2,and CD36,promoted glucose production,reduced lactate levels and inhibited hypoxic PASMC viability.Furthermore,overexpression of HIF-1αreversed the regulation of glycolysis caused by NR4A1 knockdown.Conclusion:NR4A1 enhances glycolysis in hypoxia-induced PASMCs by upregulating HIF-1α.Our findings indicate that the management of NR4A1 activity may be a promising strategy for PAH therapy.