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Congenital heart disease (CHD) is the most common form of birth defect in humans, and remains a leading non‑infectious cause of infant mortality worldwide. An increasing number of studies have demonstrated that genetic defects serve a pivotal role in the pathogenesis of CHD, and mutations in >60 genes have been causally associated with CHD. CHD is a heterogeneous disease and the genetic basis of CHD in the majority of patients remains poorly understood. In the present study, the coding exons and flanking introns of the mesoderm posterior 1 (MESP1) gene, which encodes a basic helix‑loop‑helix transcription factor required for normal cardiovascular development, were sequenced in 178 unrelated patients with CHD. The available relatives of the index patient carrying an identified mutation and 200 unrelated, ethnically‑matched healthy individuals, who were used as controls, were genotyped for MESP1. The functional characteristics of the MESP1 mutation were determined using a dual‑luciferase reporter assay system. As a result, a novel de novo heterozygous MESP1 mutation, p.Q118X, was identified in an index patient with double outlet right ventricle (DORV) and a ventricular septal defect. The nonsense mutation was absent in the 400 reference chromosomes and the altered amino acid was completely conserved evolutionarily across species. Functional assays indicated that the mutant MESP1 protein had no transcriptional activity when compared with its wild‑type counterpart. The present study firstly provided experimental evidence supporting the concept that a MESP1 loss‑of‑function mutation may contribute to the development of DORV in humans, which presents a significant insight into the molecular pathogenesis of CHD. The results highlight the potential implications for the genetic counseling and personalized treatment of patients with CHD. [ABSTRACT FROM AUTHOR]

Cervical cancer is the second most common malignancy in women worldwide and always has recurrence owing to radioresistance. MicroRNA (miRNA or miR) has been identified to relate to the sensitivity of cancer radiotherapy. Here, we investigated the potential of miRNA-320 as a biomarker for radiosensitivity by targeting β-catenin in cervical cancer. A radioresistant cervical cancer cell line, C33AR, was established, and the radioresistance of C33AR cells was confirmed by a colony-formation assay. The expression of miRNA-320 was detected by reverse transcription-quantitative polymerase chain reaction, and compared between C33A and C33AR. β-catenin, the target of miRNA-320, was determined at the protein level by western blotting after transfecting the inhibitor of miRNA-320. The expression of miRNA-320 was markedly decreased in C33AR cells, which appeared to be more radioresistant, compared with its parental cell line C33A. Target prediction suggested that miRNA-320 negatively regulated the expression of β-catenin. Knockdown of β-catenin increased C33AR radiosensitivity, which revealed that the inhibition of β-catenin could rescue the miRNA-320-mediated cell radioresistance. On the other hand, overexpressing miRNA-320 increased C33AR radiosensitivity. In conclusion, miRNA-320 regulated the radiosensitivity of C33AR cells by targeting β-catenin. This finding provides evidence that miRNA-320 may be a potential biomarker of radiosensitivity in cervical cancer. [ABSTRACT FROM AUTHOR]

Neutrophilic airway inflammation in chronic lung infections caused by Pseudomonas aeruginosa (PA) is associated with T helper (Th)17 responses. Suppressor of cytokine signaling 3 (SOCS3) is the major negative modulator of Th17 function through the suppression of signal transducer and activator of transcription (STAT)3 activation. The aim of the present study was to investigate the expression of SOCS3 in lung CD4+ T cells in a mouse model of chronic PA lung infection and the effect of exogenous SOCS3 on Th17-mediated neutrophil recruitment in vitro. A mouse model of chronic PA lung infection was established and the activation of STAT3 and Th17 response in lung tissues and lung CD4+ T cells was assessed. The protein and mRNA expression of SOCS3 in lung CD4+ T cells was analyzed by western blotting and reverse transcription-quantitative polymerase chain reaction. The authors constructed a recombinant lentivirus carrying the SOCS3 gene and transferred it into lung CD4+ T cells isolated from a mouse model. These transfected cells were stimulated with interleukin (IL)-23 in vitro a nd t he p rotein l evel of p-STAT3 and retinoid-related orphan receptor (ROR)γt was determined by western blotting. The expression of IL-17A+ cells was analyzed by flow cytometry and the level of IL-17A in cell culture supernatant was measured by ELISA. The mouse lung epithelial cell line, MLE-12, was cocultured with lung CD4+ T cells that overexpressed the SOCS3 gene and the culture supernatant was harvested and used for a chemotaxis assay. Compared with control mice, mice with chronic PA lung infection had significantly higher level of p-STAT3 and Th17 response in both lung tissues and lung CD4+ T cells. The protein and mRNA level of SOCS3 in lung CD4+ T cells increased as the chronic PA lung infection developed. Exogenous SOCS3 gene transfer in PA-infected lung CD4+ T cells decreased p-STAT3 and RORγt expression and suppressed the level of IL-17A+ cells in vitro. MLE-12 cells cocultured with SOCS3-overexpressing lung CD4+ T cells expressed a significantly lower level of neutrophil chemoattractants chemokine (C-X-C motif) ligand (CXCL) 1 and CXCL5, and recruited significantly smaller numbers of migrating neutrophils than those cocultured with control cells. SOCS3 was upregulated in lung CD4+ T cells following the activation of STAT3/Th17 axis in a mouse model of chronic PA lung infection. Exogenous SOCS3 transfer in PA-infected lung CD4+ T cells suppresses Th17-mediated neutrophil recruitment in vitro. [ABSTRACT FROM AUTHOR]

Previous genome-wide association studies have demonstrated that single nucleotide polymorphisms in T-box (TBX)5 are associated with increased susceptibility to atrial fibrillation (AF), and a recent study has causally linked a TBX5 mutation to atypical Holt-Oram syndrome and paroxysmal AF. However, the prevalence and spectrum of TBX5 mutations in patients with AF remain to be elucidated. In the present study, a cohort of 190 unrelated patients with idiopathic AF were prospectively recruited, with 400 unrelated healthy individuals recruited as controls. The coding exons and flanking introns of the TBX5 gene were sequenced in the participants. The functional characteristics of the mutant TBX5 were delineated in contrast with its wild-type counterpart using a dual-luciferase reporter assay system. As a result, a novel heterozygous TBX5 mutation, p.P132S, was identified in an index patient with AF, with a mutational prevalence of ~0.53%. Genetic analysis of the proband's family showed that the mutation co-segregated with AF, and was transmitted in an autosomal dominant pattern. The missense mutation was absent in the 800 control chromosomes, and the altered amino acid was completely evolutionarily conserved across species. Functional analyses revealed that the mutant TBX5 had significantly reduced transcriptional activity. Furthermore, the mutation markedly decreased the synergistic activation between TBX5 and NK2 homeobox 5, another transcription factor which has been causatively linked to AF. The present study was the first, to the best of our knowledge, to report on the association between a TBX5 loss-of-function mutation and increased susceptibility to AF. These results provide novel insight into the molecular mechanism underpinning AF, and have potential implications in the development of novel prophylactic and therapeutic strategies for AF, the most common form of sustained cardiac arrhythmia. [ABSTRACT FROM AUTHOR]

Dilated cardiomyopathy (DCM) is the most common form of primary myocardial disease. It is the most common cause of chronic congestive heart failure and the most frequent reason for heart transplantation in young adults. There is increasing evidence demonstrating that genetic defects are involved in the pathogenesis of idiopathic DCM. Recent studies have shown that genetically defective LRRC10 predisposes animals to DCM. However, the association of LRRC10 with DCM in humans has not been reported. In the current study, the whole coding region and flanking splice junction sites of the LRRC10 gene were sequenced in 220 unrelated patients with idiopathic DCM. The available relatives of the index patients harboring identified mutations and 200 unrelated ethnically matched healthy individuals used as controls were also genotyped for LRRC10. The functional effect of the LRRC10 mutations was analyzed in silico. As a result, two novel heterozygous LRRC10 mutations, p.L41V and p.L163I, were identified in two families with DCM, respectively, with a mutational prevalence of ~0.91%. Genetic analyses of the pedigrees showed that in each family, the mutation co-segregated with DCM was transmitted as an autosomal dominant trait with complete penetrance. The missense mutations were absent in 400 control chromosomes and the altered amino acids were completely conserved evolutionarily across various species. Functional analysis in silico indicated that the LRRC10 mutations were causative. This study firstly reports the association of LRRC10 mutations with enhanced susceptibility to DCM in humans, which provides novel insight into the molecular mechanism underpinning DCM, and contributes to the development of novel prophylactic and therapeutic strategies for DCM. [ABSTRACT FROM AUTHOR]