Effect of cyclic RNA hsa-circ-0001360 on homocysteine-induced apoptosis of human umbilical vein endothelial cells / 中国组织工程研究

BACKGROUND:Increased homocysteine level induces apoptosis of human umbilical vein endothelial cells,but the mechanism remains unclear. OBJECTIVE:To investigate the role of hsa-circ-0001360 in human umbilical vein endothelial cell apoptosis induced by homocysteine. METHODS:In vitro cultured human umbilical vein endothelial cells were divided into control group,homocysteine group,interference control group,interference control + homocysteine group,hsa-circ-0001360 interference group,hsa-circ-0001360 + homocysteine interference group,overexpression control group,overexpression control + homocysteine group,hsa-circ-0001360 overexpression group and hsa-circ-0001360 + homocysteine overexpression group.All groups were treated with 100 μmol/L homocysteine.After 72 hours of intervention,the expressions of apoptosis-related proteins Bax,Bcl-2,and Caspase-3 were detected by western blot assay.The apoptotic rate was detected by flow cytometry.Quantitative real-time PCR was used to detect the expression of hsa-circ-0001360. RESULTS AND CONCLUSION:(1)Compared with the control group,the expression of Caspase-3 and Bax was significantly increased(P<0.01),and the expression of Bcl-2 was significantly decreased(P<0.01),and the apoptotic rate was significantly increased(P<0.01)in the homocysteine group.(2)Compared with control group,the expression of hsa-circ-0001360 was significantly increased in the homocysteine group(P<0.01).(3)The expression of hsa-circ-0001360 was significantly higher in the cytoplasm than that in the nucleus(P<0.01).(4)Compared with the interference control C group and interference control + homocysteine group,the expressions of Caspase-3 and Bax were significantly decreased(P<0.01),while the expression of Bcl-2 was significantly increased(P<0.01);the apoptotic rate was significantly decreased(P<0.01)in sh-hsa-circ-0001360 interference group and sh-hsa-circ-0001360 + homocysteine interference group.(5)Compared with overexpression control group and overexpression control + homocysteine group,the expressions of Caspase-3 and Bax were significantly increased(P<0.01),while the expression of Bcl-2 was significantly decreased(P<0.01);the apoptotic rate was significantly increased(P<0.01)in the hsa-circ-0001360 overexpression group and the hsa-circ-0001360 + homocysteine overexpression group.(6)In conclusion,hsa-circ-0001360 can promote the apoptosis of human umbilical vein endothelial cells induced by homocysteine.

Inflammation and tumor microenvironment / 中南大学学报(医学版)

There is a connection between inflammation and cancer.Inflammation is one of the hallmarks of cancer,affecting tumor progression,transition to a malignant phenotype,and the efficacy of tumor chemotherapy.The tumor microenvironment impacts the biological characteristics of tumors through various specific factors and signaling mechanisms.The interaction between inflammation and the tumor microenvironment involves inflammation affecting the tumor microenvironment by inducing immune suppression,while acute inflammation promotes tumor suppression by producing anti-tumor immune responses.This review elaborates on how inflammation affects the tumor microenvironment and thus affects the progression and treatment of tumors,starting from the components of the tumor microenvironment,inflammasomes,cytokines,non-coding RNAs,and other aspects.Inflammatory factors play an important role in regulating inflammatory responses and immune reactions,and they also affect the development of tumors through various pathways in the tumor microenvironment.In addition,non-coding RNAs play an important role in the tumor microenvironment,regulating tumors and inflammation.They are involved in regulating the occurrence,development of tumors,the process of inflammation,as well as regulating inflammation-induced cancer or tumor-related inflammation,and the interaction between the tumor microenvironment,inflammatory factors,and immune cells.Therefore,gaining a deeper understanding of the interaction between inflammation and the tumor microenvironment and its connection to the occurrence and development of cancer can provide a theoretical basis for combating tumors and finding new therapeutic strategies.

Mechanism of cyclic RNA0001287 and miR-21 in the pathogenesis of diabetic retinopathy / 眼科新进展

Objective To investigate the action mechanism of cyclic RNA0001287(circ_0001287)and miR-21 in the pathogenesis of diabetic retinopathy(DR).Methods Primary human retinal pigment epithelium(phRPE)cells were iso-lated for circRNA microarray analysis.Arising retinal pigment epithelium(ARPE)-19 cells were cultured in vitro and divid-ed into the blank group,high-glucose group,negative group,si-circ group,circ_0001287 group,circ_0001287+negative group,and circ_0001287+miR-21 group.Small interfering RNA(siRNA)oligonucleotides against circ_0001287,mimics containing miR-21 sequences and miR-21 mimic plasmids were constructed.In the negative group,si-circ group,circ_0001287 group,circ_0001287+negative group and circ_0001287+miR-21 group,the empty plasmid,circ_0001287 siRNA,circ_0001287 mimics,circ_0001287 mimics+miRNA disordered sequence,and circ_0001287 mimics+miR-21 mimic plasmid were transfected into ARPE-19 cells using Lipofectamine 2000 Transfection Reagent.After transfection for 6 h,the Opti-MEM medium was replaced with a fresh normal medium.Cells in the blank group and the high-glucose group were not transfected.Cells in the blank group were cultured with culture solution containing 5.5 mmol·L-1 glucose,and cells in the high-glucose group were cultured with culture solution containing 15.5 mmol·L-1,25.5 mmol·L-1 and 35.5 mmol·L-1 glucose,respectively.Cells in other groups were treated with 35.5 mmol·L-1 glucose for 48 h.The expressions of circ_0001287 and miR-21 were detected by reverse transcription polymerase chain reaction(RT-PCR),cell proliferation activity was detected by Cell Counting Kit-8,and the targeting relationship between circ_0001287 and miR-21 was detected by Dual Luciferase Reporter Assay.RNA immunoprecipitation(RIP)assay and biotin-coupled probe pull-down assay were used to verify the targeting relationship between circ_0001287 and miR-21.Western blot was used to detect protein expression.Re-sults After screening by circRNA,the expression of hsa_circ_0001287 in phRPE cells was significantly reduced.RT-PCR detection showed that compared with the blank group,circ_0001287 expression in ARPE-19 cells in the high-glucose group decreased(P＜0.05)in a dose-dependent manner,and miR-21 expression in ARPE-19 cells gradually increased with the in-crease of glucose concentration(P＜0.05).After co-transfection of siRNA with circ_0001287 mimics,siRNA also reduced circ_0001287 expression,and the relative expression of circ_0001287 in the circ_0001287+negative group(0.70±0.03)was significantly lower than that in the negative group(0.98±0.04,P＜0.05).For cells transfected with the circ_0001287-WT plasmid,compared with the control simulation group(0.98±0.03),the relative luciferase activity of the miR-21 simulation group(0.59±0.02)decreased(P＜0.05).However,for cells transfected with circ_0001287-MUT plasmid,the relative ac-tivity of luciferase was almost the same in the control simulation group(0.96±0.05)and the miR-21 simulation group(1.00±0.04,P＞0.05).In the anti-Ago RIP experiment,miR-21 was significantly enriched in the circ_0001287 group com-pared with the control group,indicating that miR-21 could be significantly pulled down by the biotinylated circ_0001287 probe.Pull-down analysis demonstrated that compared with the control IgG,circ_0001287 specific probe pull-down sam-ples showed significant enrichment of circ_0001287 and miR-21.In this experiment,the cell proliferation rate of the circ_0001287+miR-21 group(78.25％±3.01％)was lower than that of the circ_0001287+negative group(90.88％±3.51％,P＜0.05).Compared with the blank group,the expression of PTEN protein in ARPE-19 cells in the high-glucose group treated with 35.5 mmol·L-1 glucose was significantly down-regulated(P＜0.05),the expression of PTEN protein in ARPE-19 cells in the circ_0001287 group was higher than that in the negative group(P＜0.05),and the expression of PTEN protein in ARPE-19 cells in the circ_0001287+miR-21 group was higher than that in the circ_0001287 group(P＜0.05).Conclusion The expression of circ_0001287 is down-regulated in phRPE cells and high-glucose induced ARPE-19 cells,and up-regulated circ_0001287 can inhibit the injuiy of diabetic RPE cells by adsorption of miR-21 and activation of PTEN expression.

Differential expression of cyclic RNA in peripheral blood mononuclear cells of patients with rheumatoid arthritis / 中华风湿病学杂志

Objective:To investigate the differences in the expression profiles of cyclic RNA (circRNA) in peripheral blood mononuclear cells (PBMCs) of rheumatoid arthritis (RA) and its clinical significance.Methods:Venous blood were collected from 4 patients with RA (group T) and 4 healthy subjects (group C). The expression profiles of circRNA in PBMCs of the two groups were detected by Arraystar circRNA microarray, and the differentially expressed circRNA was analyzed by clustering analysis. The binding sites for interaction between differentially expressed circRNA and miRNA were predicted, and functional analysis such as geneontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis was performed. quantitative real-time polymerase chain reaction (RT-qPCR) was used to verify the expression of partially differentially expressed circRNA in the two groups of PBMCs, and a circRNA-miRNA-mRNA regulatory network (ceRNA network) was constructed for the target circRNA with significantly differential expression. A receiver operating characteristic curve [receiver operating characteristic curve (ROC)] was established to analyze the potential diagnostic value of target circRNA. SPSS Statistics 23.0 and Graphpad Prism 8.0 were used to analyze the data, and the independent t test was used to analyze the difference between the two groups. Results:① Microarray results showed that, compared with group C, a total of 399 [fold of difference (FC)>1.5, and P<0.05] circRNA were abnormally expressed in PBMCs of group T; including 149 up-regulated and 250 down-regulated. ② Bioinformatics analysis: The prediction of the binding site of circRNA and miRNA suggested that the differentially expressed circRNA in RA might affect the inflammatory response by targeting miR-140-5p, miR-338-5p, and miR-9-5p. GO analysis showed that the differentially expressed circRNA was mainly involved in the intimal-binding organelles, protein metabolism and binding, etc. KEGG pathway analysis showed that most of the involved pathways were related to infection and human immune dysregulation. ③ The results of multi-sample RT-qPCR validation showed that the expression level of hsa_circRNA_009012 in group T was significantly higher than that in group C ( t=-4.417, P<0.01), the expression level of hsa_circRNA_101328 was significantly lower than that in group C ( t=-1.042, P<0.01), and the expression of hsa_circRNA_058230 had no significant change ( t=4.691, P>0.05). ④ ROC curve analysis indicated that hsa_circRNA_009012 had potential value in the diagnosis of RA [area under curve=0.96]. Conclusion:The expression of circRNA in PBMCs of patients with RA is imbalanced, and it may participate in the regulation of the development of RA. Among them, hsa_circRNA_009012 is expected to become a new biological marker for the diagnosis and treatment of RA.

Expression of cyclic RNA plasmacytoma variant translocation 1 in senescence of nucleus pulposus cells and its regulation mechanism / 中国组织工程研究

BACKGROUND: Cyclic RNA plasmacytoma variant translocation 1 (circPVT1) is involved in the senescence of fibroblasts, but the relationship of circPVT1 with nucleus pulposus senescence and its mechanism are still unclear. OBJECTIVE: To investigate the expression of circPVT1 in nucleus pulposus cell senescence and to explore its possible mechanism. METHODS: Human nucleus pulposus cells were cultured in vitro, and the senescence of nucleus pulposus cells was induced by ionizing radiation (5 Gy, 6 days). The expression of circPVT1 and let-7 mRNA was detected by real-time quantitative polymerase chain reaction (qRT-PCR). CircPVT1 siRNA and anti-let-7 were transfected into normal nucleus pulposus cells, which were divided into control group, si-NC+anti-NC group, si-circPVT1+anti-NC group, si-NC+anti-let-7 group, and si-circPVT1+anti-let-7 group. The expressions of circPVT1 and let-7 mRNA were detected by qRT-PCR. Cell counting kit-8 assay was used to detect the inhibition of cell proliferation. Plate cell clone formation assay was used to detect colony formation. Cell senescence was detected by SA-β-gal staining. The expressions of p21, p27, let-7 target high mobility group protein A2 (HMGA2) and KRAS were detected by western blot assay. Double luciferase activity assay was used to verify the relationship between let-7 and target regulation of HMGA2 and KRAS. RESULTS AND CONCLUSION: (1) Compared with normal nucleus pulposus cells, the expression of circPVT1 was decreased, while let-7 expression and the positive rate of SA-β-gal staining were increased in the irradiated cells (P < 0.05). (2) Compared with the control group and si-NC+anti-NC group, the si-circPVT1+anti-NC group appeared to have decreased expression of circPVT1 mRNA, HMGA2 and KRAS proteins and number of clones formed as well as increased let-7 mRNA expression, p21, p27 protein expression, cell inhibition rate and positive rate of SA-β-gal staining (P < 0.05). However, opposite changes were found in the si-NC+anti-let-7 group in relative to the control group (P < 0.05). (3) The expression of circPVT1 mRNA, clone formation, and expressions of HMGA2 and KRAS proteins in the si-circPVT1+anti-let-7 group were higher than those in the si-circPVT1+anti-NC group, and lower than those in the si-NC+anti-let-7 group. Let-7 mRNA expression, cell inhibition rate, positive rate of SA-β-gal staining, and expressions of p21 and p27 proteins in the si-circPVT1+anti-let-7 group were lower than those in the si-circPVT1+anti-NC group, and higher than those in the si-NC+anti-let-7 group (P < 0.05). Double luciferase activity assay showed that HMGA2 and KRAS were the targets of let-7. These findings indicate that inhibition of circPVT1 can inhibit the aging of nucleus pulposus cells. The mechanism may be through binding let-7 to inhibit the targeting of HMGA2 and KRAS proteins.