HAND1 Loss-of-Function Mutation Causes Tetralogy of Fallot.

As the most prevalent form of birth defect in humans worldwide, congenital heart disease (CHD) is responsible for substantial morbidity and is still the leading cause of birth defect-related demises. Increasing evidence demonstrates that genetic defects play an important role in the pathogenesis of CHD, and mutations in multiple genes, especially in those coding for cardiac core transcription factors, have been causally linked to various CHDs. Nevertheless, CHD is a genetically heterogeneous disease and the genetic determinants underpinning CHD in an overwhelming majority of patients remain elusive. In the current study, genomic DNA was extracted from venous blood samples of 165 unrelated patients with CHD, and the coding exons and splicing junction sites of the HAND1 gene, which encodes a basic helix-loop-helix transcription factor essential for cardiovascular development, were sequenced. As a result, a novel heterozygous mutation, p.R118C, was identified in a patient with tetralogy of Fallot (TOF). The missense mutation, which was absent in 600 referential chromosomes, altered the amino acid that was completely conserved evolutionarily. Biological assays with a dual-luciferase reporter assay system revealed that the R118C-mutant HAND1 protein had significantly reduced transcriptional activity when compared with its wild-type counterpart. Furthermore, the mutation significantly decreased the synergistic activation of a downstream target gene between HAND1 and GATA4, another cardiac core transcription factor associated with TOF. To our knowledge, this is the first report on the association of a HAND1 loss-of-function mutation with enhanced susceptibility to TOF in humans. The findings provide novel insight into the molecular etiology underlying TOF, suggesting potential implications for the improved prophylactic and therapeutic strategies for TOF.

Prevalence and Spectrum of NKX2-5 Mutations Associated With Sporadic Adult-Onset Dilated Cardiomyopathy.

Dilated cardiomyopathy (DCM), the most common form of primary myocardial disease, is a leading cause of congestive heart failure and the most common indication for heart transplantation. Recently, NKX2-5 mutations have been involved in the pathogenesis of familial DCM. However, the prevalence and spectrum of NKX2-5 mutations associated with sporadic DCM remain to be evaluated. In this study, the coding regions and flanking introns of the NKX2-5 gene, which encodes a cardiac transcription factor pivotal for cardiac development and structural remodeling, were sequenced in 210 unrelated patients with sporadic adult-onset DCM. A total of 300 unrelated healthy individuals used as controls were also genotyped for NKX2-5. The functional effect of the mutant NKX2-5 was investigated using a dual-luciferase reporter assay system. As a result, two novel heterozygous NKX2-5 mutations, p.R139W and p.E167X, were identified in 2 unrelated patients with sporadic adult-onset DCM, with a mutational prevalence of approximately 0.95%. The mutations were absent in 600 referential chromosomes and the altered amino acids were completely conserved evolutionarily across species. Functional assays revealed that the NKX2-5 mutants were associated with significantly reduced transcriptional activity. Furthermore, the mutations abrogated the synergistic activation between NKX2-5 and GATA4 as well as TBX20, two other cardiac key transcription factors that have been causally linked to adult-onset DCM. This study is the first to associate NKX2-5 loss-of-function mutations with enhanced susceptibility to sporadic DCM, which provides novel insight into the molecular etiology underpinning DCM, and suggests the potential implications for the genetic counseling and personalized treatment of the DCM patients.

TBX20 loss-of-function mutation associated with familial dilated cardiomyopathy.

BACKGROUND: Dilated cardiomyopathy (DCM) is a major cause of congestive heart failure, sudden cardiac death and cardiac transplantation. Aggregating evidence highlights the genetic origin of DCM. However, DCM is a genetically heterogeneous disorder, and the genetic components underlying DCM in most cases remain unknown. METHODS: The coding regions and splicing junction sites of the TBX20 gene were sequenced in 120 unrelated patients with idiopathic DCM. The available close relatives of the index patient carrying an identified mutation and 300 unrelated ethnically matched healthy individuals used as controls were genotyped for TBX20. The functional characteristics of the mutant TBX20 were assayed in contrast to its wild-type counterpart by using a dual-luciferase reporter assay system. RESULTS: A novel heterozygous TBX20 mutation, p.F256I, was identified in a family with DCM transmitted in an autosomal dominant fashion, which co-segregated with DCM in the family with complete penetrance. The missense mutation was absent in 600 control chromosomes and the altered amino acid was completely conserved evolutionarily among various species. Functional assays revealed that the mutant TBX20 had significantly diminished transcriptional activity. Furthermore, the mutation markedly reduced the synergistic activation of TBX20 with NKX2-5 or GATA4. CONCLUSIONS: This study links TBX20 loss-of-function mutation to idiopathic DCM in humans for the first time, providing novel insight into the molecular mechanism underpinning DCM.

Mutational spectrum of the NKX2-5 gene in patients with lone atrial fibrillation.

Atrial fibrillation (AF) is the most common form of sustained cardiac arrhythmia in humans and is responsible for substantial morbidity and mortality worldwide. Emerging evidence indicates that abnormal cardiovascular development is involved in the pathogenesis of AF. In this study, the coding exons and splice sites of the NKX2-5 gene, which encodes a homeodomain-containing transcription factor essential for cardiovascular genesis, were sequenced in 146 unrelated patients with lone AF as well as the available relatives of the mutation carriers. A total of 700 unrelated ethnically matched healthy individuals used as controls were genotyped. The disease-causing potential of the identified NKX2-5 variations was predicted by MutationTaster and PolyPhen-2. The functional characteristics of the mutant NKX2-5 proteins were analyzed using a dual-luciferase reporter assay system. As a result, two heterozygous NKX2-5 mutations, including a previously reported p.E21Q and a novel p.T180A mutation, were identified in two families with AF transmitted in an autosomal dominant pattern. The mutations co-segregated with AF in the families with complete penetrance. The detected substitutions, which altered the amino acids highly conserved evolutionarily across species, were absent in 700 control individuals and were both predicted to be causative. Functional analyses demonstrated that the NKX2-5 mutants were associated with significantly decreased transcriptional activity compared with their wild-type counterpart. The findings expand the spectrum of NKX2-5 mutations linked to AF and provide additional evidence that dysfunctional NKX2-5 may confer vulnerability to AF, suggesting the potential benefit for the early prophylaxis and personalized treatment of AF.

[Effects of exercise therapy at the intensity of anaerobic threshold for exercise tolerance in patients with chronic stable coronary artery disease].

OBJECTIVE: To investigate the effects of exercise therapy at the intensity of anaerobic threshold (AT) for exercise tolerance in patients with chronic stable coronary artery disease. METHODS: Forty-three patients with chronic stable coronary artery disease (3 patients after coronary arterial bypass graft (CABG) surgery, 22 patients with old myocardial infarction and 18 unstable angina pectoris undergoing successful percutaneous coronary intervention (PCI) finished twice cardiopulmonary exercise test (CPET) and followed their rehabilitation program for 3 months. Thirty-two patients finished their aerobic exercise therapy based on their individual anaerobic thresholds while 11 patients had no exercise therapy. RESULTS: The heart rate at AT intensity (97 ± 9/min) was lower than their traditional minimal target heart rate (112 ± 7/min) and lower than heart rate (115 ± 11/min) at ischemic threshold post-CPET. The O(2) consumption (10.7 ± 2.4 to 12.6 ± 2.9 ml×min(-1)×kg(-1)) (P = 0.04) and workload (37 ± 18 to 47 ± 13 J/s) (P = 0.04) at AT level and the O(2) consumption (15.3 ± 3.1 to 20.6 ± 4.2 ml×min(-1)×kg(-1), P = 0.02) and workload(68 ± 12 and 87 ± 14 J/s, P = 0.01) at peak level markedly increased after 3 months in the exercise group. And the O(2) consumption (15.3 ± 2.9 to 16.2 ± 3.1 ml×min(-1)×kg(-1)) and workload (65 ± 13 to 73 ± 16 J/s) at peak level mild increased after 3 months in the non-exercise group, but their O(2) consumption (11.0 ± 2.7 to 11.3 ± 2.8 ml×min(-1)×kg(-1)) and workload (38 ± 11 to 37 ± 9 J/s) at AT level had no obvious change. CONCLUSION: AT exercise intensity was lower than ischemic threshold post-CPET. Exercise therapy at the intensity of anaerobic threshold can improve oxygen capacity and exercise tolerance.

CASZ1 loss-of-function mutation associated with congenital heart disease.

As the most common form of birth defect in humans, congenital heart disease (CHD) is associated with substantial morbidity and mortality in both children and adults. Increasing evidence demonstrates that genetic defects play a pivotal role in the pathogenesis of CHD. However, CHD is of great heterogeneity, and in an overwhelming majority of cases, the genetic determinants underpinning CHD remain elusive. In the present investigation, the coding exons and flanking introns of the CASZ1 gene, which codes for a zinc finger transcription factor essential for the cardiovascular morphogenesis, were sequenced in 172 unrelated patients with CHD. As a result, a novel heterozygous CASZ1 mutation, p.L38P, was identified in an index patient with congenital ventricular septal defect (VSD). Genetic scanning of the mutation carrier's available family members revealed that the mutation was present in all affected patients but absent in unaffected individuals. Analysis of the proband's pedigree showed that the mutation co-segregated with VSD, which was transmitted as an autosomal dominant trait with complete penetrance. The missense mutation, which altered the amino acid that was highly conserved evolutionarily, was absent in 200 unrelated, ethnically-matched healthy subjects used as controls. Functional deciphers by using a dual-luciferase reporter assay system unveiled that the mutant CASZ1 had significantly reduced transcriptional activity as compared with its wild-type counterpart. To the best of our knowledge, the current study firstly identifies CASZ1 as a new gene predisposing to CHD in humans, which provides novel insight into the molecular mechanisms underlying CHD and a potential therapeutic target for CASZ1-associated CHD, suggesting potential implications for personalized prophylaxis and therapy of CHD.

Effect of Danggui Buxue Tang on immune-mediated aplastic anemia bone marrow proliferation mice.

To investigate the pharmacological effects of Danggui Buxue Tang (DBT) on immune-mediated aplasia anemia mice. The model of immune-mediated aplasia anemia mice was induced by means of (60)Co γ-ray irradiation and mixed cells of thymus and lymphnode of DBA/2 mice infusion through tail vein, the parameters tested indices were as following: blood picture, bone marrow nucleated cell count (BMNC), murine colony-forming unit-megakaryocytes (CFU-GM) of bone marrow cells, murine colony-forming unit-erthroid (CFU-E) and burst forming unit-erythroid (BFU-E). The results showed that DBT could not only withstand significantly decreation of blood cells by immune-mediated, but also stimulate on the growth of bone marrow colony cell and increase the weight of hemopoietic progenitor of bone marrow. Therefore, DBT had an obvious treat effect on immune-mediated aplasia anemia models mice.

A novel GATA4 loss-of-function mutation responsible for familial dilated cardiomyopathy.

Dilated cardiomyopathy (DCM) is the most common form of primary myocardial disorder and is associated with substantial morbidity and mortality. Increasing evidence suggests that genetic risk factors play an important role in the pathogenesis of idiopathic DCM. However, DCM is a genetically heterogeneous disease, and the genetic defects responsible for DCM in an overwhelming majority of cases remain to be identified. In the present study, the entire coding region and the splice junction sites of the GATA4 gene, which encodes a cardiac transcription factor essential for cardiogenesis, were sequenced in 150 unrelated patients with idiopathic DCM. The available relatives of the index patient harboring an identified mutation and 200 unrelated ethnically matched healthy individuals used as controls were genotyped. The functional characteristics of the mutant GATA4 were delineated in contrast to its wild-type counterpart using a luciferase reporter assay system. As a result, a novel heterozygous GATA4 mutation, p.V291L, was identified in a family with DCM inherited in an autosomal dominant pattern, which co-segregated with DCM in the family with complete penetrance. The missense mutation was absent in 400 control chromosomes, and the altered amino acid was completely conserved evolutionarily among species. Functional analysis revealed that the GATA4 mutant was associated with significantly diminished transcriptional activity. The findings expand the mutational spectrum of GATA4 linked to DCM and provide novel insight into the molecular etiology involved in DCM, suggesting the potential implications in the early prophylaxis and allele-specific treatment for this common type of cardiomyopathy.

The effects of Polygonum cuspidatum extract on wound healing in rats.

AIM OF THE STUDY: Polygonum cuspidatum has long been used as a traditional medicine inducing wound healing. In this study, the extract from the Chinese medicinal herb Polygonum cuspidatum was investigated on its wound healing activity, in order to obtain an accurate elucidation of its traditional use value. MATERIALS AND METHODS: After creating wound healing model on the back of rats, the extract from the Chinese medicinal herb Polygonum cuspidatum was applied. Wound healing rates were calculated at 3, 7, 14, and 21 days after the wounding, and tissues were harvested at 1, 3, 7, 14 and 21 days for histological and immunohistochemistry analysis. The stages of wound granulation tissues were evaluated histopathologically. The expression of TGF-ß1 was determined by immunohistochemically. RESULTS: Wound healing rates were significantly higher at 3, 7, 14 and 21 days in the extract group than in the control (p<0.05). Histological results showed more well-organized bands of collagen, more fibroblasts and hair follicle and less inflammatory cells in the extract group. The immunohistochemical results revealed that TGF-ß1 increased in the extract group on day 1, 3 and 7 post-wounding (p<0.05). CONCLUSION: The present study has shown that the extract from the Chinese medicinal herb Polygonum cuspidatum possesses wound healing activity, and thus provided the evidence for its traditional use value.

Novel GATA5 loss-of-function mutations underlie familial atrial fibrillation.

OBJECTIVE: This study aimed to identify novel GATA5 mutations that underlie familial atrial fibrillation. METHODS: A total of 110 unrelated patients with familial atrial fibrillation and 200 unrelated, ethnically matched healthy controls were recruited. The entire coding region of the GATA5 gene was sequenced in 110 atrial fibrillation probands. The available relatives of the mutation carriers and 200 controls were subsequently genotyped for the identified mutations. The functional effect of the mutated GATA5 was characterized using a luciferase reporter assay system. RESULTS: Two novel heterozygous GATA5 mutations (p.Y138F and p.C210G) were identified in two of the 110 unrelated atrial fibrillation families. These missense mutations cosegregated with AF in the families and were absent in the 400 control chromosomes. A cross-species alignment of GATA5 protein sequence showed that the altered amino acids were completely conserved evolutionarily. A functional analysis revealed that the mutant GATA5 proteins were associated with significantly decreased transcriptional activation when compared with their wild-type counterpart. CONCLUSION: The findings expand the spectrum of GATA5 mutations linked to AF and provide novel insights into the molecular mechanism involved in the pathogenesis of atrial fibrillation, suggesting potential implications for the early prophylaxis and personalized treatment of this common arrhythmia.

Quantitative evaluation of cardiopulmonary functional reserve in treated patients with pulmonary embolism.

BACKGROUND: There is no research, either at home or abroad, focusing on assessing the cardiopulmonary functional reserve and exercise tolerance in patients with pulmonary embolism (PE), but the benefits of early exercise are well recognized. The goals of this study were to assess cardiopulmonary functional reserve in treated PE patients using the inert gas rebreathing method of the cardiopulmonary exercise test (CPET), and to compare it with traditional methods. METHODS: CPET on the bicycle ergometer were performed in 40 patients with age, gender, body mass index, systolic blood pressure, and pulmonary function matched. The first group was the PE group composed of 16 PE patients (5 male, 11 female) who were given the standard antithrombotic therapy for two weeks. The second group was composed of 24 normal individuals (10 male, 14 female). Both groups were evaluated by cardiac ultrasound examination, 6-minute walking test (6MWT), and CPET. RESULTS: (1) Right ventricular systolic pressure (RVSP) in the PE group increased significantly compared to the control group, (34.81 ± 8.15) mmHg to (19.75 ± 3.47) mmHg (P < 0.01). But neither right atrial end-systolic diameter (RASD) nor right ventricular end-diastolic diameter (RVDD) in the PE patients had changed when compared with the controls. The 6-minute walk distance was significantly reduced in the PE patients compared with normal subjects, (447.81 ± 79.20) m vs. (513.75 ± 31.45) m (P < 0.01). Both anaerobic threshold oxygen consumption (VO(2)AT) and peak oxygen consumption (VO(2)peak) were significantly lower in patients with PE, while CO(2) equivalent ventilation (VE/VCO(2) slope) was higher; VO(2)AT (9.44 ± 3.82) ml×kg(-1)×min(-1) vs. (14.62 ± 2.93) ml×kg(-1)×min(-1) (P < 0.01) and VO2peak (12.26 ± 4.06) ml×kg(-1)×min(-1) vs. (23.46 ± 6.15) ml×kg(-1)×min(-1) (P < 0.01) and VE/VCO(2) slope 35.47 ± 6.66 vs. 26.94 ± 3.16 (P < 0.01). There was no significant difference in resting cardiac output (CO) between the PE and normal groups, whereas peak cardiac output (peak CO) and the difference between exercise and resting cardiac output (ΔCO) were both significantly reduced in the PE group; peak CO (5.97 ± 2.25) L/min to (8.50 ± 3.13) L/min (P < 0.01), ΔCO (1.29 ± 1.59) L/min to (3.97 ± 2.02) L/min (P < 0.01). (2) The 6-minute walk distance did not correlated with CPET except for the VO2 peak in patients with PE, r = 0.675 (P < 0.01). CONCLUSIONS: The cardiopulmonary functional reserve was reduced in patients with PE. CPET is an accurate, quantitative evaluation of cardiopulmonary functional reserve for PE patients.

Novel GATA5 loss-of-function mutations underlie familial atrial fibrillation

OBJECTIVE: This study aimed to identify novel GATA5 mutations that underlie familial atrial fibrillation. METHODS: A total of 110 unrelated patients with familial atrial fibrillation and 200 unrelated, ethnically matched healthy controls were recruited. The entire coding region of the GATA5 gene was sequenced in 110 atrial fibrillation probands. The available relatives of the mutation carriers and 200 controls were subsequently genotyped for the identified mutations. The functional effect of the mutated GATA5 was characterized using a luciferase reporter assay system. RESULTS: Two novel heterozygous GATA5 mutations (p.Y138F and p.C210G) were identified in two of the 110 unrelated atrial fibrillation families. These missense mutations cosegregated with AF in the families and were absent in the 400 control chromosomes. A cross-species alignment of GATA5 protein sequence showed that the altered amino acids were completely conserved evolutionarily. A functional analysis revealed that the mutant GATA5 proteins were associated with significantly decreased transcriptional activation when compared with their wild-type counterpart. CONCLUSION: The findings expand the spectrum of GATA5 mutations linked to AF and provide novel insights into the molecular mechanism involved in the pathogenesis of atrial fibrillation, suggesting potential implications for the early prophylaxis and personalized treatment of this common arrhythmia.