Effects of PDGFRα on melanocyte apoptosis induced by hydrogen peroxide

AIM: To investigate the effects of platelet-derived growth factor receptor α (PDGFRα) on melanocyte apoptosis induced by hydrogen peroxide (H₂O₂). METHODS: Melanocyte PIGI was used as the research object. After exposed to H₂O₂ at different concentrations, the cell viability was detected by MTT assay. The PIGI cells were transfec-ted with empty vector pCMV6 or PDGFRα over-expression vector pCMV6-PDGFRα. The transfection efficiency was determined by RT-qPCR and Western blot. The effect of H₂O₂ on the viability of the PIGI cells after over-expression of PDGFRα was measured by MTT assay. The cell apoptosis was analyzed by flow cytometry. The protein levels of p38, p-p38 and cleaved caspase-3 in the cells were detected by Western blot. DCDHF-DA was used to estemate the generation of reactive oxygen species (ROS) in the cells. RESULTS: The viability of PIGI cells decreased after exposed to H₂O₂ (P<0.05), and the half maximal inhibitory concentration of H₂O₂ was 0.7 mmol/L. Transfection with PDGFRα over-expression vector successfully induced high expression of PDGFRα at mRNA and protein levels in the PIGI cells, and increased the viability of the cells with H₂O₂ treatment (P<0.05). Over-expression of PDGFRα decreased the apoptotic rate of PIGI cells treated with H₂O₂ (P<0.05), and the level of ROS in the cells (P<0.05). The protein levels of cleaved caspase-3 and p-p38 were also decreased (P<0.05). CONCLUSION: PDGFRα inhibits the apoptosis of melanocytes induced by H₂O₂, partially reverses the growth inhibition of melanocytes by H₂O₂, and decreases the ROS level. The mechanism may be related to regulating the protein levels of p-p38 and cleaved caspase-3 in the cells.     

乳腺发育和乳腺疾病中细胞凋亡基因的表达规律及其调控

阐述了细胞凋亡的形态变化、细胞凋亡的途径以及细胞凋亡在乳腺发育过程和乳腺疾病的发生及防御中的表达。研究乳腺细胞凋亡的基本规律和基因调控过程,能更好的了解乳腺发育过程,并用相关基因作为诊断乳腺疾病的指标。     

Effects of NOB1 gene silencing on drug sensitivity and invasion and migration abilities of human colon cancer SW480 cells

AIM:To investigate the effect of NOB1 gene expression knock-down by transfection of small interfering RNA (siRNA) on the viability, drug sensitivity, apoptosis, cell cycle distribution, and invasion and migration abilities of human colon cancer SW480 cells. METHODS:NOB1 siRNA was transfected into SW480 cells using Lipofectamine 3000. The mRNA and protein levels of NOB1 in the SW480 cells were determined by real-time PCR and Western blot. The cell viability and sensitivity to different chemotherapeutic drugs (cisplatin, 5-fluorouracil, oxaliplatin and capecitabine) were detected by MTT assay after knock-down of NOB1 gene expression in the SW480 cells. The apoptosis and cell cycle distribution of SW480 cells were analyzed by flow cytometry. The invasion and migration abilities of SW480 cells were detected by Transwell assay. RESULTS:After transfection with NOB1 siRNA, the mRNA and protein levels of NOB1 in the SW480 cells were significantly decreased (P<0.05). Compared with control group and control siRNA group, the viability of SW480 cells in NOB1 siRNA group was significantly decreased at 24~72 h. The half maximal inhibitory concentrations of the chemotherapy drugs cisplatin, 5-fluorouracil, oxaliplatin and capecitabine were significantly decreased. The apoptotic rate was significantly increased and the cell cycle were blocked. The cell invasion and migration abilities were significantly reduced (P<0.05). CONCLUSION:Knock-down of NOB1 gene expression inhibits the viability and invasion and migration abilities of colon cancer SW480 cells, and promotes drug sensitivity and apoptosis. NOB1 may be a new target for diagnosis and treatment of colon cancer.     

Advances in apoptosis induced by natural drugs

Apoptosis, a form of cell death, has generated considerable interest in recent years. Much progress has been made on the apoptosis induced by natural drgus, including component or mixture of plant, animal, mineral or marine materials. This review discusses some of the natural drugs that induce apoptosis and the possible mechanisms.     

Poly(ADP-ribose) polymerase and cell injury

Poly(ADP-ribose) polymerase (PARP) is a protein-modifying and nucleotide-polymerizing enzyme. As a critical element in DNA repair, PARP can be activated by DNA strand breaks. Excessive activation of PARP, however, can deplete NAD⁺and ATP, leads to cell death. Cleavage of PARP by activated caspase-3 play an important role in cell apoptosis.     

Expression of caspase-4 in Hodgkin's lymphoma and anaplastic large cell lymphoma

AIM: This study is based on the result of the study in HL and ALCL employing gene chip technique, in which writer found that there was distinctly different expression of caspase-4 between HL and ALCL cell lines at the level of mRNA. From the point of view, we try to identify at the level of protein whether there is different expression of this gene in HL and ALCL tissues as well. METHODS: HE staining, the monoclonal antibodies CD30 (BerH2), CD15 (C3D-1), CD20 (L26) and CD45RO (UCHL1) were used for selecting the cases of HL and ALCL. Specific high affinitive anti-caspase-4 polyclonal antibody was used by immunohistochemical staining to analyze the expression of caspase-4 in 18 cases of HL and 15 cases of ALCL. RESULTS: The expression of caspase-4 demonstrated a strong positive staining in all ALCL cases (15/15,100%), whereas negative in 16 HL cases (88.8%), while other two cases were weakly stained (11.2%), showing a distinct difference (P<0.01) between two groups. CONCLUSIONS: (1) The diverse expression of caspase-4 gene in HL and ALCL groups implies a different mechanism of oncogenesis and the different defects of signal transduction pathway of apoptosis in these two entities of lymphomas. (2) Clarification of this gene might be useful for the differential diagnosis of HL and ALCL. Furthermore, it probably provides theoretically gene therapy strategies for lymphoma in the future.     

Apoptosis induced by berbamine in K562 cells correlates with the expression levels of bcr/abl gene and P210

AIM: To explore the effect of berbamine(BER) on apoptosis in K562 cells and its possible molecular mechanisms. METHODS: The apoptosis rate was measured by flow cytometry while electron microscopy and DNA electrophoresis were used to evaluate the characteristic changes of apoptosis, RT-PCR and Western blot were used to examine the expression levels of apoptosis related gene bcr/abl and BCR/ABL protein. RESULTS: By FCM, the apoptosis rate of K562 cells treated with 8.0 mg/L BER for 24 h and 72 h increased from (29.20±3.82)% to (61.77±4.35)% (P＜0.01); The typical apoptosis morphologic changes and the DNA ladder were more clearly observed. After treated with BER 0 to 16.0 mg/L for 24 h, the expression levels of bcr/abl mRNA and P210 (semiquantity value) decreased quickly from 1.19±0.02 to 0.73±0.02 (P＜0.01) and from 1.04±0.02 to 0.63±0.01 (P＜0.01), respectively. CONCLUSION: BER induces apoptosis of K562 cells in a time-and-concentration-dependent manner, the decline of bcr/abl mRNA and P210 may play an important role in the apoptotic effect of BER in K562 cells. BER could be used as a new clinical trials for bcr-abl⁺ diseases such as CML.     

Advances in the mechanism of retina ischemia-reperfusion injury

Retinal ischemia-reperfusion injury (RIRI) is a common cause of visual impairment and blindness. At the cellular level, ischemic and reperfuion retinal injury consists of a self-reinforcing destructive cascade involving oxidative stress initiated by energy failure, inflammatory reaction, calcium influx, increased glutamatergic stimulation and neuronal depolarisation and apoptosis. A number of animal models and analytical techniques have been used to study the retinal ischemia-reperfusion injury, we now understand much better than ever before in the mechanism of RIRI, and an increase in the therapeutic strategies has been developed experimentally to attenuate the detrimental effects of retinal ischemia-reperfusion injury. Thus far, however, success in the laboratory has not been translated to the clinic. Given the increasing understanding of the events involved in ischemia-reperfusion neuronal injury, it is hoped that clinically effective treatments for retinal ischemia-reperfusion injury will soon be available.     

Stat5b signaling pathway regulates the expression of Survivin and promotes apoptosis in human colon cancer cells

AIM: The purpose of the study was to examine colon cancer cell lines to determine whether Stat5b/Survivin plays an important role in the process of apoptosis in colon cancer cells. METHODS: Protein lysates were extracted from colon cancer cells. Human colon cancer cell line HT29 was transfected with Stat5b antisense oligonucleotide mediated by liposome. MTT assay was used to measure the proliferation. Flow cytometry was applied to analyze the cell cycle and apoptosis. EMSA was used to detect the activity of Stat5. Western blotting was applied to measure the expression of Stat5, p-Stat5, cyclin D1, Survivin, Bcl-2 and Bcl-x L. RESULTS: Targeting of Stat5 using antisense oligonucleotide against the translation site resulted in apoptosis and downregulaed the expressions of Stat5, p-Stat5, cyclin D1 and Survivin, but not Bcl-2 and Bcl-xL. CONCLUSION: Constitutive activation of Stat5 is associated with the carcinogenesis of colon cancer cells. Blocking of Stat5 signaling inhibits the expression of Survivin and induces apoptosis in colon cancer cells.     

Protective effects of adenosine on cultured rat hippocampal neurons after oxygen-glucose deprivation

AIM:To investigate the protective effects of adenosine on cultured rat hippocampal neurons after oxygen-glucose deprivation.METHODS:The control and adenosine-treated hippocampal neurons cultured for 12 d were exposed to oxygen-glucose deprivation environment for 0.5-4 h and then cultured with original medium in normoxia for 24 h. The soma area, survival rate, effluxes of lactate dehydrogenase (LDH)and apoptosis of neurons were observed.RESULTS:The soma area, effluxes of lactate dehydrogenase from neurons and apoptosis were increased while survival rate of neurons was decreased after oxygen-glucose deprivation compared with those pre-oxygen-glucose deprivation. Compared with the control, after oxygen-glucose deprivation the soma area, effluxes of lactate dehydrogenase from neurons and apoptosis were decreased, however, the survival rate of neurons was increased in the adenosine group.CONCLUSION:Oxygen-glucose deprivation can lead to the severe damage of cultured hippocampal neurons, and adenosine can reduce neuronal injury induced by oxygen-glucose deprivation.