Objective To observe the effects of SARS-CoV-2 infection on the morphology, proliferation, apoptosis, cell cycle, and immune response function of mouse retinal photoreceptor cells (661w cells). MethodsA cell experiment. Logarithmic growth phase 661w cells were cultured in vitro and transfected with angiotensin-converting enzyme 2 (ACE2) overexpressing lentivirus to construct ACE2 overexpressing 661w cells that could be infected with SARS-CoV-2 pseudovirus (hereafter referred to as ‘pseudovirus’). The 661w cells were divided into three groups: the normal group (untreated), the siACE2 group (overexpressing ACE2 and not infected with the pseudovirus) and the infected group (overexpressing ACE2 and infected with the pseudovirus), in which the infected group was 5 TU/ml pseudovirus group, 15 TU/ml pseudovirus group, 30 TU/ml pseudovirus group and 50 TU/ml pseudovirus group, and the cells were infected with the pseudovirus for 12, 24, 48 and 72 h, respectively. The infected group was infected with 5 TU/ml pseudovirus group, 15 TU/ml pseudovirus group, 30 TU/ml pseudovirus group and 50 TU/ml pseudovirus group, respectively, for 12, 24, 48 and 72 h. Fluorescence microscopy was used to observe the transfection efficiency of ACE2; protein immunoblotting (Western blot) was used to detect the relative expression level of ACE2 in the cells; light microscope was used to observe the morphology of the cells in the normal and the infected groups; cell proliferation was detected by Cell Counting Kit-8 (CCK8) assay; flow cytometry was used to detect the cell cycle; Western blot and real-time quantitative polymerase chain reaction (qPCR) were used to detect the relative expression of interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α), B lymphocytoma-2 (Bcl-2), Bcl-2-associated X-protein (Bax) proteins and mRNA in the cells of siACE2 group, infected group (30 TU/ml pseudovirus group); qPCR was used to detect the relative expression of nuclear factor (NF)- κB1 and NF-κB2, as well as NF- kB enhancer (P65) and precursor protein (P100) in cells of the siACE2 group and the infected group (30 TU/ml pseudovirus group). One-way ANOVA was used for comparison between multiple groups; t-test was used for comparison between two groups. Results Compared with the siACE2 group, the cells in the infected group showed different degrees of crumpling, and with the increase of the concentration and time of pseudovirus induction, the crumpling of the cells worsened, and the number of cells decreased. Compared with the normal group, the cells in the infected group showed a gradual decrease in cell viability with the prolongation of pseudovirus induction time, and the difference was no statistically significant (F=0.840, 0.412, 1.498, 1.138; P＞0.05), and the apoptotic index of the cells induced in the 30 and 50 TU/ml pseudovirus group was significantly elevated, and the difference was statistically significant (F=2.523, 6.716, 3.477, 3.421; P＜0.05). At 72 h of pseudovirus induction, compared with the siACE2 group, the G1 phase cells in the 30 TU/ml pseudovirus group were significantly increased, and the difference was statistically significant (t=3.812, P＜0.05); the relative expression of IL-6, TNF-α, Bax protein and mRNA in the cells was up-regulated (t=7.601, 6.039, 3.088, 5.193, 6.427, 7.667; P＜0.05), the relative expression of Bcl-2 protein and mRNA was down-regulated (t=3.614, 6.777; P＜0.05), and the relative expression of NF-κB1, NF-κB2, P65, and P100 mRNA was significantly up-regulated with statistically significant differences (t=3.550, 3.074, 3.307, 4.218; P＜0.05). ConclusionSARS-CoV-2 infection may inhibit photoreceptor cell proliferation, promote apoptosis and cycle blockade by activating the NF-κB signalling pathway.
ObjectiveTo study the effects of astaxanthin on the apoptosis after spinal cord injury in rats.MethodsOne hundred and forty-four healthy adult Sprague Dawley rats were divided into experimental group, control group, and sham group according to the random number table (n=48). In the control group and the experimental group, the modified Allen’s method was used to make the spinal cord injury model; in the sham group, only the lamina was cut without damaging the spinal cord. At immediate after operation, the rats in the experimental group were given intragastric administration of astaxanthin (75 mg/kg) twice a day; and the rats in the control group and the sham group were given equal amount of olive oil by gavage twice a day. BBB score was used to assess the motor function at 1 day and 1, 2, 3, and 4 weeks after operation. The malondialdehyde (MDA) content was determined by the thiobarbituric acid method at 24 hours after operation; and the activity of superoxide dismutase (SOD) was determined by the xanthine oxidase method. Apoptosis index (AI) was determined by TUNEL method at 6, 24, and 48 hours after operation. At 48 hours after operation, the water content of spinal cord was measured by dry-wet weight method, the lesion ratio of spinal cord was calculated, the ultrastructure of the spinal cord was observed by transmission electron microscopy, and ultrastructure scoring was performed using the Kaptanoglu score method.ResultsThe BBB score in the control group and the experimental group was significantly lower than that in the sham group at each postoperative time point (P<0.05); and the BBB score in the experimental group were significantly higher than that in the control group at 1-4 weeks postoperatively (P<0.05). The MDA content in the control group and the experimental group was significantly higher than that in the sham group at 24 hours after operation, and in the experimental group was significantly lower than in the control group (P<0.05). The SOD activity in the control group and the experimental group was significantly lower than that in the sham group, and in the experimental group was significantly higher than in the control group (P<0.05). At each time point postoperatively, the AI in the control group and the experimental group was significantly higher than that in the sham group, and in the experimental group was significantly lower than in the control group (P<0.05). At 48 hours after operation, the water content of spinal cord, the lesion ratio of spinal cord, and the ultrastructure score in the control group and the experimental group were significantly higher than those in the sham group, and in the experimental group were significantly lower than in the control group (P<0.05).ConclusionAstaxanthin can inhibit the lipid peroxidation, reduce the apoptosis, reduce the spinal cord edema, reduce the spinal cord lesion, reduce the histopathological damage after spinal cord injury, and improve the motor function of rats with spinal cord injury, and protect the spinal cord tissue, showing an obvious neuroprotective effect.
Objective To investigate the effect of heme oxygenase 1 (HO-1) on the apoptosis of human degenerated nucleus pulposus (NP) cells induced by tumor necrosis factor α (TNF-α), and explore its possible molecular mechanism. Methods The intervertebral disc tissues were derived from patients with lumbar intervertebral disc herniation. Then, the NP cells were cultured in vitro and the third generation of NP cells were used for subsequent experiments. Cell counting kit 8 (CCK-8) method was used to observe the proliferative effect of TNF-α on the NP cells in vitro at the concentration of 10, 20, 50, 100, and 200 ng/mL. The most apropriate concentration was selected according to the result of CCK-8. The NP cells were cultured with basal medium (control group), TNF-α (TNF-α group), TNF-α and CoPP 10 μmol/L (CoPP group), and TNF-α and ZnPP 15 μmol/L (ZnPP group), respectively. After cultured, the cell poptosis was detected by Hoechst staining and flow cytometry; the expression of cleaved Caspase-3, epithelial membrane protein 1 (EMP-1), HO-1, and p-P65 proteins were detected by Western blot. In order to further explore the potential molecular mechanisms of HO-1 for cell apoptosis, the NP cells were cultured with TNF-α (TNF-α stimulated group), TNF-α and pyrrolidine dithiocarbamate (PDTC) 5 μmol/L (TNF-α+PDTC stimulated group), respectively. Then the cell apoptosis rate was measured by flow cytometry at 24 hours after cultured. Results The optimal concentration of TNF-α was 100 ng/mL. Hoechst staining showed that a few apoptotic cells could be observed in control group and CoPP group; the apoptosis-like nucleis were observed in TNF-α group and ZnPP group, which was the most significant in ZnPP group. Flow cytometry showed that the cell apoptosis rates of TNF-α group, CoPP group, and ZnPP group were significantly increased when compared with the control group (P<0.05). Compared with TNF-α group, the cell apoptosis rate in CoPP group decreased (P<0.05), while in ZnPP group it increased (P<0.05). Western blot showed that the expression of HO-1 protein in TNF-α group was decreased, and the expressions of cleaved Caspase-3, EMP-1, and p-P65 proteins were increased when compared with the control group (P<0.05). Compared with TNF-α group, the expression of HO-1 protein in CoPP group increased, and the expressions of cleaved Caspase-3, EMP-1, and p-P65 proteins were reduced (P<0.05); the expression of HO-1 protein in ZnPP group decreased (P<0.05), the expressions of cleaved Caspase-3 and EMP-1 proteins increased (P<0.05), and the expression of p-P65 protein was not significantly changed (P>0.05). Compared with TNF-α stimulated group, the cell apoptosis rate in TNF-α+PDTC stimulated group was significantly reduced (t=3.076, P=0.031). Conclusion HO-1 can inhibit the apoptosis of degerated NP cells induced by TNF-α, and its mechanism effect is by inhibiting the nuclear factor кB signaling pathway.
ObjectiveTo study the effects and mechanism of Octreotide to inhibit the proliferation of human gastric cancer cells in vitro. MethodsHuman gastric cancer cell line SGC7901 was treated with Octreotide. Human fibroblast cell line HF and 5FU were used as control. MTT assay and fluorescent microscopy as well as flow cytometry were performed in this study. ResultsOctreotide inhibited the growth of SGC7901 in vitro within certain concentrations. The suppression was quantity dependent but did not occur when up to a certain concentration. There was no difference between Octreotide and 5FU in their inhibition on SGC7901. Octreotide had no effects on normal human fibroblast cell line HF. When SGC7901 was treated with Octreotide, the typical apoptotic bodies were identified by flow cytometry and fluorescent microscopy. ConclusionOctreotide can inhibit the proliferation of human gastric cancer cell line SGC7901 in vitro. The induction of apoptosis by Octreotide might be the primary mechanism.
ObjectiveTo establish the co-culture model of mice's early embryo and tumor cells in Vitro to observe the embryonic development and biologic behavior of tumor cells in the same microenvironment and discuss their interaction. MethodsWe acquired 2-cell embryos from mice, and then co-cultured them with tumor cell lines of mice in Vitro. We observed the development of embryos in Vitro and the rates of 4-cell embryos, morula and blastocyst formation. The transwell chamber was used for culture. Methylthiazolyldiphenyl-tetrazolium method was used to test the proliferative activity of tumor cells, while the flow cytometry was used to test its apoptosis. The interaction of co-cultured embryos and tumor cells was analyzed by propidium iodide staining and immunohistochemical technique. ResultsThe co-cultured 2-cell embryos could continue surviving and developing. The rates of 4-cell embryos, morula and blastocyst formation increased significantly in the co-cultured group (P<0.05). There was no significant difference in the proliferative activity and apoptosis of tumor cells between the co-cultured group and the control group (P>0.05). Tumor-free ring formed between the trophoblast and tumor cells. We could observe tumor cells stacked around the tumor-free ring. However, no difference in expression of proliferating cell nuclear antigen and B-cell lymphoma leukemia-2 was observed in tumor cells stacking around the tumor-free ring compared with those elsewhere. ConclusionThe development of 2-cell embryos is enhanced in the co-culture model. The proliferative activity and apoptosis of tumor cells are not affected in this model. A tumor-free ring can form between trophoblast and tumor cells. However, the proliferative activity of tumor cells is not affected by this ring.
Objective To investigate the effect of ginkgolide B (GB) on cysteinyl aspartate specific proteinase-3 (Caspase-3)/chromosome 10 deletion phosphatase-tension protein homologue (PTEN)/protein kinase B (Akt) pathway and cell proliferation and apoptosis in hypoxia/reoxygenation cardiomyocytes. Methods H9C2 cells were cultured in vitro. A control group was cultured in serum-free DMEM high glucose medium at 37°C and 5% CO2 for 28 hours. The remaining groups were prepared with hypoxia/reoxygenation models. A GB low-dose group and a GB high-dose group were treated with GB pretreatment with final concentration of 50 μmol/L and 200 μmol/L respectively at 1 h before hypoxia/reoxygenation. A carvedilol group was treated with carvedilol of a final concentration of 10 μmol/L at 1 h before hypoxia/reoxygenation. The proliferation and apoptosis of H9C2 cells were detected, and the levels of lactate dehydrogenase (LDH), malondialdehyde (MDA), reactive oxygen species (ROS), PTEN, Akt, phosphorylated Akt (p-Akt) and Caspase-3 in H9C2 cells were also detected. Results Compared with the control group, the proliferation rate of H9C2 cell, and the levels of PTEN, Akt and p-Akt in other groups decreased, and the apoptosis rate, and the levels of LDH, MDA, ROS and Caspase-3 increased (P<0.05). Compared with the hypoxia/reoxygenation group, the proliferation rate of H9C2 cell, and the levels of PTEN, Akt and p-Akt in all GB dose groups and the carvedilol group increased; the apoptosis rate, and the levels of LDH, MDA, ROS and Caspase-3 decreased, and the effect of GB was in a dose dependent manner; however, the effect of GB was not as strong as carvedilol (P<0.05). Conclusion GB can inhibit H9C2 cell apoptosis and promote H9C2 cell proliferation by activating Caspase-3/PTEN/Akt pathway.
Objective To study the effect of 5-fluorouracil (5-FU) induced apoptosis of the rectal carcinoma cell line HR8348 in vitro and the relationship between apoptosis induced by 5-FU and the expression of bcl-2，bcl-xl，bax and p53,and to investigate the possible mechanism of apoptosis of rectal carcinoma cell line HR8348 induced by 5-FU.Methods After treatment with 5-FU for 24 h,the apoptotic index was detected by methyl green and pyronine Y staining and by terminal deoxynucleotidyl transferase (TdT)mediated dUTP nick end labeling (TUNEL).The bcl-2,bcl-xl,bax and p53 gene expression of HR8348 cells were examined by immunohistochemical method.Results After treatment with 5-FU,the apoptotic index of experiment group was significantly increased,there was significant difference as compared with the control.Exposed to 5-FU for 12 h,24 h and 36 h,the expression of bcl-2 of HR8348 cell line remained unchanged,but the expression of bcl-xl slightly diminished,while the expression of bax was remarkly increased,the expression of p53 was not detected in both experiment and control groups.Conclusion This results indicate that 5-FU may induce apoptosis of rectal carcinoma cell line HR8348 and the possible mechanism of apoptosis induction is through upregulation of bax expression and the change of bax to bcl-xl ratio.
Objective To summarize recent research advancement on gene therapy for hepatic ischemia-reperfusion injury (IRI). Methods Relevant references about basic and clinical researches of hepatic IRI were collected and reviewed. Results Recent experimental researches indicated that the expression of several genes and cytokines could protect hepatic cells by suppressing cell apoptosis, decreasing the production of oxyradical, remaining and improving portal venous flow, promoting bilifaction, self immunoloregulation and decreasing inflammatory reaction, so that it could decrease IRI. Conclusion IRI could be decreased by regulating the expressing of target genes or transducing relative genes in vivo, but the path of gene transfer and the selection and optimization of gene carrier still need more basic and clinical researches to prove.
ObjectiveTo summarize the biological function of extracellular matrix metalloproteinase inducer (EMMPRIN) in tumor progression, and its roles in clinical diagnosis and treatment in recent years. MethodsLiteratures about the recent studies on molecular structure of EMMPRIN and biological function in tumor progression were reviewed according to the results searched from PubMed database. ResultsEMMPRIN play important roles in the tumor progression, involved in inducing the degradation of extracellula matrix, promoting angiogenesis, inhibiting apoptosis, enhancing chemoresistance and so on. ConclusionEMMPRIN could be a potential therapeutic target in turmor.
Objective To observe the growth of xenografted tumor in nude mice after DDX46 expression decreased, and to further study the role of DDX46 in the development and progression of esophageal squamous cell carcinoma. Methods DDX46-shRNA mediated RNAi was applied to silencing DDX46 in Eca-109 cells. Twenty-five female BALB/c nude mice were divided into 3 groups: an experiment group (DDX46-shRNA-LV, n=10), a control group (Control-LV, n=10) and a blank control group (Het-1A, n=5). The prepared Eca-109 cells of DDX46-shRNA-LV and Control-LV were subcutaneously injected into the right armpit of mice (4×106 cells per mouse), while Het-1A cells were subcutaneously injected into the bilateral armpits of mice (4×106 cells per side). Tumor growth was monitored twice a week on the 14th day after injection. Tumor volume was measured with calipers, in vivo imager to observe the fluorescence of each group. Further, western blotting analysis was used to detect the changes of apoptosis signaling molecules in xenografted tumor after DDX46 silence. Results The growth of xenografted tumor in nude mice was significantly slower in the DDX46-shRNA-LV group than that in the Control-LV group throughout the study period (P<0.001). Western blotting analysis showed that silencing DDX46 effectively suppressed the expression of DDX46, and upregulated the expression of cleaved Caspase-3 and cleaved PARP-1 in xenografted tumor (P<0.01). Conclusion DDX46 is involved in the development and progression of esophageal squamous cell carcinoma, and the silence of DDX46 expression can inhibit the growth of esophageal squamous cell carcinoma, which probably by positive regulation of apoptosis signaling pathway.