Mechanism of Piezo1 channel activation promoting increase in intracellu-lar calcium concentration of rat coronary smooth muscle cells / 中国病理生理杂志

AIM:To investigate the mechanism of Piezo1 channel activation promoting the increase in intra-cellular Ca2+ concentration([Ca2+]i)of rat coronary artery smooth muscle cells(CASMCs).METHODS:The primary CASMCs of SD rats were cultured,and the expression and subcellular localization of Piezo1 in the cells were observed by immunofluorescence staining.The Piezo1 and stromal interaction molecule 1(STIM1)in CASMCs were knocked down by siRNA transfection,and the expression levels of the proteins were detected by Western blot.Utilizing laser confocal mi-croscopy,the change of[Ca2+]i in CASMCs was detected by Fluo-4 AM fluorescent probes.RESULTS:It was confirmed by immunofluorescence staining that the expression of Piezo1 existed in primary rat CASMCs.Immunofluorescence staining also showed that Piezo1 was co-located with sarco-/endoplasmic reticulum Ca2+-ATPase 2(SERCA2),mitochondrial outer membrane protein TOM20 and nuclear membrane protein lamin B1.Western blot results showed that the protein expres-sion levels of STIM1 and Piezo1 were significantly down-regulated by siRNA transfection(P<0.05).Compared with con-trol group,Yoda1,the agonist of Piezo1,could increase the extracellular Ca2+ influx of CASMCs(P<0.01).However,the Ca2+ influx mediated by Yoda1 was not affected by the inhibition of L-type calcium channels.Treatment with Yoda1 in-creased the intracellular Ca2+ release of CASMCs(P<0.01).However,inhibition of calcium channels on endoplasmic re-ticulum,ryanodine receptor and inositol 1,4,5-triphosphate receptor,did not affect intracellular Ca2+ release mediated by Yoda1.After the Ca2+ in endoplasmic reticulum was emptied using thapsigargin(TG),Yoda1 also mediated the Ca2+ re-lease of other organelles in CASMCs(P<0.01).After inhibition of L-type calcium channels,treatment with store-operated calcium channel(SOCC)inhibitor BTP2 or knockdown of STIM1 led to the decrease in extracellular Ca2+ influx of CASMCs mediated by Yoda1(P<0.01).Treatment with TG increased the release of Ca2+ from the endoplasmic reticulum of CASMCs after knockdown of Piezo1(P<0.05),but the extracellular Ca2+ influx mediated by TG was not affected.After inhibition of L-type calcium channels and SOCC,knockdown of Piezo1 led to the decreases in intracellular Ca2+ release and extracellular Ca2+ influx induced by Yoda1(P<0.01).CONCLUSION:The Piezo1 agonist orchestrates the influx of extracellular Ca2+ by activating Piezo1 channels on the cell membrane and inducing the indirect activation of SOCC.More-over,it facilitates the release of Ca2+ from organelles.Consequently,these pathways synergistically elevate the[Ca2+]i of rat CASMCs.

Effect of Fto gene knockout on calcium regulation and aortic smooth muscle contraction in diabetic mice / 中国病理生理杂志

AIM:To investigate the influence of fat mass and obesity-associated(Fto)gene on the aberrant contraction of aortic smooth muscle in diabetes mellitus(DM)mice,and to explore the mechanism of Fto gene underlying the calcium regulation.METHODS:Smooth muscle-specific Fto gene knockout(FtoSMKO)mice were generated using Cre-loxP technology.The experiment involved 3 groups of mice:wild-type(WT)group,DM model group and FtoSMKO-DM group,with 15 mice in each group.In DM group and FtoSMKO-DM group,type 1 DM was induced by intraperitoneal injec-tion of streptozotocin.The mice in WT group were injected with equal volume of citric acid-sodium citrate buffer solution.The influences of different drugs on the contraction responses of aortic smooth muscle in mice were analyzed using a multi-myograph system.The expression level of FTO protein in the aortic tissues was detected by Western blot.RESULTS:(1)Compared with WT mice,the expression levels of FTO protein in the aortic tissues of DM mice were significantly in-creased(P＜0.01).(2)The expression level of FTO protein in smooth muscle was significantly decreased after knockout of Fto gene(P＜0.01).Compared with WT group,the mice in DM group exhibited a significant decrease in body weight and a marked increase in fasting blood glucose level(P＜0.05).There were no noticeable differences in body weight or fasting blood glucose level between FtoSMKO-DM group and DM group(P＞0.05).(3)The contraction responses of aortic smooth muscle in DM group were substantially increased by phenylephrine compared with WT group.Specifically,vaso-constriction responses mediated by non-L-type calcium channels and store-operated calcium channels(SOCC)were signifi-cantly enhanced in DM group.In addition,the responses mediated by inositol 1,4,5-trisphosphate receptors(IP3R),which facilitate calcium release from the sarcoplasmic reticulum,were significantly enhanced.However,the responses mediated by caffeine-activated ryanodine receptors(RyR),which also facilitate calcium release from the sarcoplasmic re-ticulum,were significantly inhibited(P＜0.05).(4)Compared with DM group,the phenylephrine-induced contraction re-sponses of aortic smooth muscle in FtoSMKO-DM group were greatly weakened(P＜0.05).In particular,the vasoconstriction responses mediated by non-L-type calcium channels and SOCC in FtoSMKO-DM group were greatly suppressed(P＜0.05),while those mediated by caffeine-activated RyR were dramatically boosted(P＜0.05).However,IP3R-mediated responses were not affected(P＞0.05).CONCLUSION:Smooth muscle-specific Fto gene knockout suppresses contractile hyperre-sponsiveness in the aortic smooth muscle of DM mice,which may be attributed to involvement of FTO protein in calcium regulation in the vascular smooth muscle.

Values of combined detection of polygene methylation in stool for the diagnosis of colorectal cancer and precancerous lesions / 肿瘤研究与临床

Objective:To investigate the methylation status of SDC2, PPP2R5C and ADHFE1 genes in stool and their values in the screening of colorectal cancer and precancerous lesions.Methods:From August 2020 to March 2021, 64 patients with colorectal cancer, 72 patients with adenoma, 33 patients with hyperplastic polyps and 59 healthy people were recruited from Qingdao Central Hospital Affiliated to Qingdao University, and the morning stool samples were collected from the research subjects. The genomic DNA was extracted and modified with sulfite. The methylation status of SDC2, PPP2R5C and ADHFE1 genes were detected by methylation specific polymerase chain reaction (MSP), and the fecal occult blood test (FOBT) was performed. Taking the pathological results as the gold standard, receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to compare the effect of combined detection of methylation of three genes and FOBT in predicting colorectal cancer and precancerous lesions. R-Studio software was used to construct a nomogram for the prediction of colorectal cancer with combined detection of gene methylation in stool and other clinical features, and the calibration and validation were performed.Results:The positive rates of combined detection of methylation of SDC2, PPP2R5C and ADHFE1 genes in stool were higher than those of FOBT in colorectal cancer+adenoma [74.3% (101/136) vs. 47.1% (64/136), χ2 = 23.20, P = 0.001], colorectal cancer [90.6% (58/64) vs. 70.3% (45/64), χ2 = 8.91, P = 0.003] and adenoma [59.7% (43/72) vs. 26.4% (19/72), χ2 = 14.43, P = 0.002]. There was no significant difference in the positive rates in hyperplastic polyps [21.2% (7/33) vs. 6.1% (2/33), χ2 = 0.12, P = 0.125] and healthy controls [10.2% (6/59) vs. 8.5% (5/59), χ2 = 4.01, P = 1.000]. The combined detection of gene methylation was better than FOBT in the prediction of colorectal cancer + adenoma [AUC: 0.85 (95% CI 0.80-0.91) vs. 0.71 (95% CI 0.64-0.78), P < 0.05], especially in the prediction of adenoma [AUC: 0.82 (95% CI 0.74-0.89) vs 0.64 (95% CI 0.57-0.69), P < 0.001]. The sensitivity and specificity of ADHFE1 gene methylation status in predicting colorectal cancer were high (90.6% and 96.6%). In colorectal cancer patients over 50 years old, the positive rate of combined detection of gene methylation was higher than that of FOBT [90.2% (55/61) vs. 68.9% (42/61), P < 0.05]. The nomogram calibration curve for predicting colorectal cancer constructed based on the combined detection of gene methylation and each clinical feature showed a high degree of concordance between the predicted and observed diagnostic performance of colorectal cancer. Conclusions:The methylation levels of SDC2, PPP2R5C AND ADHFE1 genes in stool are increased in patients with colorectal cancer or adenoma. The combined detection of gene methylation is expected to be a non-invasive method for the screening of colorectal cancer and precancerous lesions.

Association study between candidate genes involved in cell-cell adhesion and non-syndromic cleft lip with or without cleft palate in Chinese population / 北京大学学报(医学版)

Objective:To explore the association and gene-environment interaction between single nu-cleotide polymorphisms (SNPs)involved in cell-cell adhesion and non-syndromic cleft lip with or without cleft palate (NSCL/P)among Chinese population.Methods:A total of 806 NSCL/P trios were drawn by an international consortium,which conducted a genome-wide association study (GWAS)using a case-parent trio design to investigate genes affecting risks to NSCL/P.The transmission disequilibrium test (TDT)was used to explore the association between cell-cell adhesion genes,including CDH1,CT-NNB1,PVRL1,PVRL2,PVRL3,ACTN1,VCL,LEF1,and NSCL/P.Conditional Logistic regression models were used to estimate effects on risk of exposed and unexposed children.Four common maternal exposures including maternal smoking,environmental tobacco smoke,alcohol consumption and multivita-min supplementation during pregnancy were included in this study.Results:A total of 226 SNP markers were tested after quality control in this study.Although 23 SNPs in three genes (CTNNB1,CDH1, ACTN1)showed nominal significant association with NSCL/P in the TDT (P 0.000 2).Tests for gene-environment interaction yielded significant results be-tween rs7431 27 in ACTN1 and environmental tobacco smoke (P =0.000 1 )with an estimated OR (case |G and E)=2.00(95%CI:1 .23 -3.26)and OR (case |G no E)=0.59 (95%CI:0.38 -0.90).Among the lower P value results in gene-environment tests,there were no significant results be-tween rs1 475034,rs370535,rs227341 9 in ACTN1,rs1 06871 in CTNNB1 and environmental tobacco smoke interaction.There were also no significant results between rs7634000,rs2971 366,rs2634553, rs1 489032,rs762481 2 in PVRL3 and multivitamin supplementation during pregnancy in gene-environ-ment tests(P >0.000 2).Conclusion:There is no association between cell-cell adhesion genes,inclu-ding CDH1,CTNNB1,PVRL1,PVRL2,PVRL3,ACTN1,VCL,LEF1,and NSCL/P when the genes are considered alone.But our results suggest that SNPs in ACTN1 may influence the risk to NSCL/P through gene-environment interaction.

Substitute popliteal vein valve operation for primary deep vein insufficiency of lower limbs / 中国普通外科杂志

Objective To investigate the clinical value of substitute popliteal vein valve operation (SPVSO) for primary lower limb deep vein insufficiency(DVIS). Methods The clinical data of 859 cases(907 legs) of DVIS who underwent SPVSO in the past 10 years in our hospital were analyzed retrospectively. Results Symptoms of edema and fatigue distinctly reduced or disappeared after the operation.Pigmentation in the lower portion of the leg began to disappear in 1 week, and nearly or totally disappeared within 2 weeks after the operation.Ulcer in the lower portion of the leg recovered three weeks after the operation. Patients were followed up for 6 to 120 months. The effective rate within 60 months was 96.8%, and the effective rate over 60 months was 87.2%. Conclusions The curative effect of SPVSO on primary deep vein insufficiency of lower extremity is definite and it is worthy to be clinical practice.