Patient-specific induced pluripotent stem cells as“disease-in-adish”models for inherited cardiomyopathies and channelopathies–15 years of research

Among inherited cardiac conditions,a special place is kept by cardiomyopathies(CMPs)and channelopathies(CNPs),which pose a substantial healthcare burden due to the complexity of the therapeutic management and cause early mortality.Like other inherited cardiac conditions,genetic CMPs and CNPs exhibit incomplete penetrance and variable expressivity even within carriers of the same pathogenic deoxyribonucleic acid variant,challenging our understanding of the underlying pathogenic mechanisms.Until recently,the lack of accurate physiological preclinical models hindered the investigation of fundamental cellular and molecular mechanisms.The advent of induced pluripotent stem cell(iPSC)technology,along with advances in gene editing,offered unprecedented opportunities to explore hereditary CMPs and CNPs.Hallmark features of iPSCs include the ability to differentiate into unlimited numbers of cells from any of the three germ layers,genetic identity with the subject from whom they were derived,and ease of gene editing,all of which were used to generate“disease-in-a-dish”models of monogenic cardiac conditions.Functionally,iPSC-derived cardiomyocytes that faithfully recapitulate the patient-specific phenotype,allowed the study of disease mechanisms in an individual-/allele-specific manner,as well as the customization of therapeutic regimen.This review provides a synopsis of the most important iPSC-based models of CMPs and CNPs and the potential use for modeling disease mechanisms,personalized therapy and deoxyribonucleic acid variant functional annotation.

Glycophorin variants and contents of sialic acid and total sulfhydryl groups on erythrocyte membranes of residents in a malaria hyperendemic area

Abstract Objective To conduct a screening survey of glycophorin (GP) variants and observe the content changes of sialic acid (SA) and total sulfhydryl (SH) groups on the erythrocyte membranes among residents in a tertian malaria hyperendemic area of Guizhou Province. Methods GP variants were detected in the erythrocyte hemolysates of 173 local residents at two villages of Libo County by SDS PAGE on 10% to 15% gradients gel and Western immunoblotting. Their SA and total SH group contents were estimated in erythrocyte membranes by spectrophotometric methods. 114 healthy subjects in Changsha and 49 individuals at a neighbouring village of the above area showing low morbidity of malaria served as normal and endemic controls respectively. Results Three distinct types of GP variants were found among 19 propositi in this hyperendemic area. The incidence of GP variants was 7.9% (8/101) at Yaolu Village whose population was mainly composed of Yao ethnic group;while that of Buyi ethnic group at Maolan Village was higher (15.3%; 11/72).The erythrocyte membrane contents of SA in residents at both villages exhibited a very significant tendency of decline (P<0.01), whereas those of total SH groups increased prominently in residents of Yaolu Village only (P<0.05). Conclusions The frequency of GP variants in this hyperendemic area does not depend upon the severity of malarial prevalence. The evident reduction of SA contents in the residents may be related to the breaking down of the SA residues on membrane GPs by the invasion of Plasmodium vivax.

LncRNA AFAP1-AS1/miR-27b-3p/VEGF-C axis modulates stemness characteristics in cervical cancer cells

Background:Long non-coding RNA(lncRNA)actin filament-associated protein 1 antisense RNA 1(AFAP1-AS1)functions as a competing endogenous RNA to regulate target genes expression by sponging microRNAs(miRs)to play cancer-promoting roles in cancer stem cells.However,the regulatory mechanism of AFAP1-AS1 in cervical cancer(CC)stem cells is unknown.The present study aimed to provide a new therapeutic target for the clinical treatment of CC.Methods:Hyaluronic acid receptor cluster of differentiation 44 variant exon 6(CD44v6)(+)CC cells were isolated by flow cytometry(FCM).Small interfering RNAs of AFAP1-AS1(siAFAP1-AS1)were transfected into the(CD44v6)(+)cells.The levels of AFAP1-AS1 were measured by quantitative real-time PCR(qRT-PCR).Sphere formation assay,cell cycle analysis,and Western blotting were used to detect the effect of siAFAP1-AS1.RNA pull-down and luciferase reporter assay were used to verify the relationship between miR-27b-3p and AFAP1-AS1 or vascular endothelial growth factor(VEGF)-C.Results:CD44v6(+)CCcells had remarkable stemness and a high level ofAFAP1-AS1.However,AFAP1-AS1knockdownwithsiAFAP1-AS1suppressed the cell cycle transitionofG(1)/S phase and inhibited self-renewal ofCD44v6(+)CCcells,the levels of the stemnessmarkers octamer-binding transcription factor 4(OCT4),osteopontin(OPN),and cluster of differentiation 133(CD133),and the epithelialmesenchymal transition(EMT)-related proteins Twist1,matrix metalloprotease(MMP)-9,and VEGF-C.In the mechanism study,miR-27b-3p/VEGF-C signaling was demonstrated to be a key downstream of AFAP1-AS1 in the CD44v6(+)CC cells.Conclusions:LncRNA AFAP1-AS1 knockdown inhibits the CC cell stemness by upregulating miR-27b-3p to suppress VEGF-C.