Intestinal Cckbr-specific knockout mouse as a novel model of salt-sensitive hypertension via sodium over-absorption

OBJECTIVES To investigate the value of CCKBR^(fl/fl)villin-Cre mice as a mouse model of salt-sensitive hypertension(SSH).METHODS In the first part,2-month-old CCKBR^(fl/fl)villin-Cre mice(CKO)and control CCKBR^(fl/fl)mice(WT)were fed with normal diet(0.4%NaCl)or high salt diet(4%NaCl),separately for 6 weeks.In the rescue study,one week of hydrochlorothiazide or saline injection were treated with the CKO mice fed high salt diet.The blood pressure,biochemical indexes,and the expression of small intestinal sodium transporters(NHE3,NKCC1,eNaC)was detected.The organ injury markers(MMP2/MMP9)and the histopathological changes of kidneys were observed,whereas the changes of duodenal sodium absorption were detected by small intestinal perfusion in vivo.RESULTS The CCKBR^(fl/fl)villin-Cre mice with high salt intake exhibited high blood pressure,increased duodenal sodium absorption and urinary sodium excretion,and with renal injury.The protein expression of NHE3,NKCC1 and eNaC were also significant increase in the intestine of CKO-HS mice.Treatment with hydrochlorothiazide remarkably attenuated the elevated blood pressure by high salt absorption in the CCKBR^(fl/fl)villin-Cre mice,but no significant histopathological changes were observed.CONCLUSIONS These results support a crucial role of intestinal Cckbr deficiency on SSH development and the diuretic antihypertension effect in CCKBR^(fl/fl)villin-Cre mice.The CCKBR^(fl/fl)villin-Cre mice with the high salt intake may serve as a stable model of salt-sensitive hypertensive induced by sodium overloading.

Clinical characteristics and management of coexistent cardiomyopathy in patients with bicuspid aortic valve

BACKGROUND Bicuspid aortic valve(BAV)is the most common congenital heart disease.However,the prevalence,clinical characteristics,and current management of BAV associated with inherited cardiomyopathy,including hypertrophic cardiomy-opathy(HCM),dilated cardiomyopathy(DCM),and left ventricular noncompaction(LVNC)have not been well described.METHODS Consecutive patients diagnosed with BAV at a large tertiary cardiovascular referral center between 2009 and 2018 were retrospectively assessed for HCM,DCM,and LVNC based on clinical and echocardiographic criteria.Patients with coexist-ent conditions were investigated further.RESULTS Of 3533 patients with BAV screened,57(1.6%)had concomitant cardiomyopathy.BAV was combined with HCM in 30 of these patients,with DCM in 19,and with LVNC in eight.Forty-six patients(80.7%)were male,and the mean age at first dia-gnosis was 47 years for BAV with HCM,49 years for BAV with DCM,and 35 years for BAV with LVNC.Heart failure and aortic valve dysfunction were common in these patients,and the prevalence of coexisting aortopathy was 43.3%,26.3%and 25.0%,re-spectively,for BAV with HCM,DCM and LVNC.During the index hospitalization,24 of the 57 patients(42.1%)underwent sur-gery,16(28%)underwent aortic valve and/or aortic surgery,and 16 of the 30 patients with HCM had a Morrow procedure.There were no deaths or other major adverse cardiovascular events.CONCLUSIONS The prevalence of inherited cardiomyopathy was higher in our patients with BAV than in the general popula-tion.Aortopathy and heart failure were common,with almost half of patients requiring surgery at diagnosis.

Tuberculosis in Takayasu arteritis: a retrospective study in 1105 Chinese patients

Background Tuberculosis (TB) infection has been reported to have a possible relationship with the occurrence and clinical course of Takayasu arteritis (TA). We aimed to describe the characteristics of TB in a large population of TA patients. Methods We included a total of 1105 patients with TA, who were hospitalized between January 1992 and December 2017. Comparisons of clinical features were made according to the presence of TB. Results Among the 1105 patients, 109 (9.9%) had TB, including 53 patients (48.6%) diagnosed with TB before the onset of TA, 23 (21.1%) with a concurrent diagnosis of TB and TA, and 24 patients (22.0%) who developed TB after TA. Pulmonary TB was the most frequently identified (97 patients, 89.0%). Patients with TB had more frequent involvement of the pulmonary artery and experienced more chest discomfort and constitutional symptoms but had less interventional treatment. Demographic characteristics, comorbid diseases, and use of steroids were similar between patients with and without TB. Conclusions The proportion of Chinese TA patients with TB was not low, and about half of the patients had TB before TA. Pulmonary TB was the most common. Pulmonary artery involvement and pulmonary hypertension was more frequent in TA patients with TB.

Xinfuli improves cardiac function, histopathological changes and attenuate cardiomyocyte apoptosis in rats with doxorubicin-induced cardiotoxicity

Background Xinfuli Granule （XG）, a compound Chinese herbal medicine, has been effectively used in China for the treatment of heart failure for more than fifty years. This study aimed to investigate the effects and the underlying mechanisms of Xinfuli in rats with dox- orubicin-induced cardiotoxicity. Methods Sprague-Dawley rats were treated with intraperitoneal injection of Doxorubicin （DOX, 2.5 mg/kg per week） for six weeks, and then randomly divided into four groups which received intragastrically administration of normal saline （control group） or different dosage of XG （0.675 g/kg per day, 1.35 g/kg per day, and 2.7g/kg per day, respectively） for six weeks. Transtho- racic echocardiography was performed to evaluate the left ventricular fractional shortening （LVFS） and left ventricular ejection fraction （LVEF） before and after the XG treatment and histopathologic changes were also examined. Myocardial cell apoptosis was detected by TUNEL staining. The expression of related genes and proteins were analyzed using immunohistochemical staining. Results Compared to those in the control group, rats in XG treated groups showed significantly improved cardiac function and milder cardiac histopathological changes, lower cardiomyocyte apoptosis index, higher expression of Bcl-2 and lower expression of Bax. Conclusions Administration of XG improves cardiac function and histopathological changes in rats with doxorubicin-induced cardiotoxicity. These effects are associated with inhibition of cardiomyocyte apoptosis, perhaps via regulation of Bcl-2 and Bax protein expression.

Anemia in patients with Takayasu arteritis: prevalence, clinical features, and treatment

Background Anemia is a common comorbidity of patients with Takayasu arteritis(TA). This study evaluated the prevalence, clinical characteristics, and treatment in Chinese TA patients with anemia. Methods This retrospective study included 533 consecutive patients hospitalized for TA from January 2009 to April 2018. Anemia was diagnosed on the basis of hemoglobin level, according to World Health Organization criteria. Results A total of 194 patients(36.4%) were diagnosed with anemia. Most had mild anemia(177, 91.2%). Female patients were predominant(92.8% of anemic patients). Normocytic anemia(62.9%) was the most common pattern. Anemic patients were more likely than non-anemic patients to have dizziness(29.4% vs. 21.2%), low body mass index(22.0 ± 3.6 vs. 22.9 ± 3.4 kg/m2), and active disease stage(64.9% vs. 50.1%);pulmonary involvement(12.4% vs. 26.8%), pulmonary hypertension(12.9% vs. 20.1%) and pulmonary hypertensive-target drugs(2.8% vs. 11.6%) were less common among anemic than non-anemic patients(all P < 0.05). Larger left ventricular end-diastolic diameter and lower left ventricular ejection fraction were observed in anemic patients. Over a median follow-up of four months, the increase of hemoglobin in anemic patients was associated with the use of iron supplementation. Conclusions Anemia is a very common concurrent condition in TA, especially in young, female patients. Patients with anemia are more likely to be in the active disease stage. Iron supplementation helps increase hemoglobin.

Twenty-four-hour ambulatory blood pressure changes in older patients with essential hypertension receiving monotherapy or dual combination antihypertensive drug therapy

Objective To evaluate the differences in 24-hour ambulatory blood pressure (BP) in older patients with hypertension treated with the five major classes of antihypertensive drugs,as monotherapy or dual combination therapy,to improve daytime and nighttime BP control. Methods We enrolled 1920 Chinese community-dwelling outpatients aged ≥ 60 years and compared ambulatory BP values and ambulatory BP control (24-hour BP < 130/80 mmHg;daytime mean BP < 135/85 mmHg;and nighttime mean BP < 120/70 mmHg),as well as nighttime BP dip patterns for monotherapy and dual combination therapy groups. Results Patients’ mean age was 71 years,and 59.5% of patients were women. Calcium channel blockers (CCBs) constituted the most common (60.3% of patients) monotherapy,and renin–angiotensin system (RAS) blockers combined with CCBs was the most common (56.5% of patients) dual combination therapy. Monotherapy with beta-blockers (BB) provided the best daytime BP control. The probabilities of having a nighttime dip pattern and nighttime BP control were higher in patients receiving diuretics compared with CCBs (OR = 0.52,P = 0.05 and OR = 0.41,P = 0.007,respectively). Patients receiving RAS/diuretic combination therapy had a higher probability of having controlled nighttime BP compared with those receiving RAS/CCB (OR = 0.45,P = 0.004). Compared with RAS/diuretic therapy,BB/CCB therapy had a higher probability of achieving daytime BP control (OR = 1.27,P = 0.45). Conclusions Antihypertensive monotherapy and dual combination drug therapy provided different ambulatory BP control and nighttime BP dip patterns. BB-based regimens provided lower daytime BP,whereas diuretic-based therapies provided lower nighttime BP,compared with other antihypertensive regimens.

Etiology spectrum and clinical characteristics of renal artery stenosis in a Chinese cohort

OBJECTIVE To analyze the causes of renal artery stenosis(RAS)and compare the clinical characteristics in accordance with the primary disease among patients aged from 30 to 50.METHODS Patients were grouped by etiologies of RAS.Groups were retrospectively examined and compared regarding demographic data,clinical manifestations,laboratory findings,and imaging findings.RESULTS A total of 152 patients(74 females,78 males;mean age:40.70±6.01 years)were enrolled,including 84 patients(55.3%)with atherosclerosis(AS),46 patients(30.3%)with Takayasu arteritis(TA),18 patients(11.8%)with fibromuscular dysplasia(FMD),and four patients(2.6%)with other etiologies.Patients in AS group had greater body mass index,higher prevalence of comorbidities and higher rate of smoking and drinking history.TA patients showed more constitutional symptoms and vascular findings,and higher erythrocyte sedimentation rate.RAS in both AS group and TA group mainly located on ostia and proximal segments,but RAS in FMD group mainly involved middle to distal segment of renal artery.The AS group had significantly lesser stenosis than the other groups.Although renal function evaluated by the estimated glomerular filtration rate did not significantly differ among the groups,the incidence of kidney shrinkage was significantly higher in the TA and FMD groups(39.1%and 50%,respectively)than in the AS group(8.3%).The FMD group had milder cardiac damage than other groups.CONCLUSIONS AS was the most common cause of RAS in patients aged from 30 to 50,followed by TA and FMD.The etiology of RAS should be carefully distinguished based on clinical manifestations,laboratory findings,and imaging to ensure that proper treatment is provided.

Implication of a novel truncating mutation in titin as a cause of autosomal dominant left ventricular noncompaction

BACKGROUND Mutation in the titin gene(TTN)in left ventricular noncompaction(LVNC)has been reported with a highly heterogeneous prevalence,and the molecular mechanisms underlying the pathogenesis of TTN gene mutation are uncharacteri-zed.In the present study,we identified a novel TTN mutation in a pedigree with LVNC and investigated the potential pathogenic mechanism by functional studies.METHODS The whole-genome sequencing with linkage analysis was performed in a 3-generation family affected by autoso-mal dominant LVNC cardiomyopathy.The clustered regularly interspaced short palindromic repeats associated protein 9(CRISPR/Cas9)technology was used to establish novel truncating mutation in TTN in a rat cardiomyoblast H9C2 cell line in vitro,in which functional studies were carried out and characterized in comparison to its wild-type counterpart.RESULTS A novel truncating mutation TTN p.R2021X was identified as the only plausible disease-causing variant that segreg-ated with disease among the five surviving affected individuals,with an interrogation of the entire genome excluding other po-tential causes.Quantitative reverse transcription-polymerase chain reaction and cellular immunofluorescence supported a haplo-insufficient disease mechanism in titin truncation mutation cardiomyocytes.Further functional studies suggested mitochondrial abnormities in the presence of mutation,including decreased oxygen consumption rate,reduced adenosine triphosphate produc-tion,impaired activity of electron translation chain,and abnormal mitochondrial structure on electron microscopy.Impaired aut-ophagy under electron microscopy accompanied with activation of the Akt-mTORC1 signaling pathway was observed in TTN p.R2021X truncation mutation cardiomyocytes.CONCLUSIONS The TTN p.R2021X mutation has a function in the cause of a highly penetrant familial LVNC.These findings expand the spectrum of titin’s roles in cardiomyopathies and provide novel insight into the molecular basis of titin-truncating variants-associated LVNC.

A novel missense mutation in obscurin gene in a Chinese consanguineous family with left ventricular noncompaction

BACKGROUND Left ventricular noncompaction(LVNC) is an increasingly recognised cardiomyopathy of which a significant percentage are genetic in origin. The purpose of the present study was to identify potential pathogenic mutation leading to disease in a Chinese LVNC family.METHODS A 3-generation family affected by LVNC was recruited. Clinical assessments were performed on available family members, with clinical examination, ECG, echocardiography and cardiac MRI. The proband(Ⅰ-2), the proband’s daughter(Ⅱ-1, affected) and mother(Ⅲ-1, unaffected) were selected for WGS. Sanger sequencing were performed in all of the 4 surviving family members.RESULTS Combined whole genome sequencing with linkage analysis identified a novel missense mutation in the giant protein obscurin(OBSCN NM_001098623, c.C19063T), as the only plausible disease-causing variant that segregates with disease among the four surviving individuals, with interrogation of the entire genome excluding other potential causes. This c.C19063T missense mutation resulted in p.R6355W in the encoded OBSCN protein. It affected a highly conserved residue in the C terminus of the obscurin-B-like isoform between the PH and STKc domains, which was predicted to affect the function of the protein by different bioinformatics tools.CONCLUSIONS Here we present clinical and genetic evidence implicating the novel R6355W missense mutation in obscurin as the cause of familial LVNC. This expands the spectrum of obscurin’s roles in cardiomyopathies. It furthermore highlights that rare obscurin missense variants, currently often ignored or left uninterpreted, should be considered to be relevant for cardiomyopathies and can be identified by the approach presented here. This study also provided new insights into the molecular basis of OBSCN mutation positive LVNC.

Effect of Aging on Hardening Behavior of 15-5 PH Stainless Steel

Microstructure transformation and aging hardening behavior of 15-5 PH stainless steel were studied by optical microscopy （OM）, X-ray diffraction （XRD） and transmission electron microscopy （TEM）. The results showed that the 15-5 PH stainless steel consists of NbC precipitates and lath matensite with a high dislocation density after solution treatment. With increasing aging temperature and aging time, the martensitic laths were resolved gradually. Meanwhile, the nanometric-sized Cu precipitates gradually coarsened and lost their coherency with＇the martensite matrix, which exhibited an elliptical shape finally. Fine Cu precipitates can lead to significant dispersion hardening effect, while the coarsened Cu precipitates have no contribution to strengthening. The reversed austenite was observed in the speci- mens aged at 550 ℃ and above; moreover, the amount of reversed austenite increased as aging temperature in- creased. The precipitation hardening behavior of 15-5 PH stainless steel may depend on the balance between the softening caused by the formation of reversed austenite and the hardening caused by the precipitation of copper.

A novel phenotype with splicing mutation identified in a Chinese family with desminopathy

Background:Desminopathy, a hereditary myofibrillar myopathy, mainly results from the desmin gene (DES) mutations.Desminopathy involves various phenotypes, mainly including different cardiomyopathies, skeletal myopathy, and arrhythmia.Combined with genotype, it helps us precisely diagnose and treat for desminopathy.Methods:Sanger sequencing was used to characterize DES variation, and then a minigene assay was used to verify the effect of splice-site mutation on pre-mRNA splicing.Phenotypes were analyzed based on clinical characteristics associated with desminopathy.Results:A splicing mutation (c.735+1G>T) in DES was detected in the proband.A minigene assay revealed skipping of the whole exon 3 and transcription of abnormal pre-mRNA lacking 32 codons.Another affected family member who carried the identical mutation, was identified with a novel phenotype of desminopathy, non-compaction of ventricular myocardium.There were 2 different phenotypes varied in cardiomyopathy and skeletal myopathy among the 2 patients, but no significant correlation between genotype and phenotype was identified.Conclusions:We reported a novel phenotype with a splicing mutation in DES, enlarging the spectrum of phenotype in desminopathy.Molecular studies of desminopathy should promote our understanding of its pathogenesis and provide a precise molecular diagnosis of this disorder, facilitating clinical prevention and treatment at an early stage.

Association of interleukin-18 gene polymorphisms with Takayasu arteritis in a Chinese Han population

Background:Interleukin-18(IL18)gene polymorphisms are related to many inflammatory and autoimmune diseases.However,a correlation analysis between IL18-607C/A and-137G/C gene polymorphisms and Takayasu arteritis(TA)is lacking.Methods:This study enrolled 200 patients with TA as the case group and 334 region-,age-,and sex-matched healthy subjects as the control group.We genotyped alleles and genotypes at positions-607 and-137 of the IL18 gene and analyzed the distribution frequencies.Mann-Whitney U test,t test,Chi-squared test and Hardy-Weinberg equilibrium were performed.Results:After adjusting for risk factors,the adjusted odds ratios and 95%confidence intervals at position-607C/A were 0.533,0.391 to 0.880(P=0.010);0.266,0.586 to 1.002(P=0.051);and 0.122,0.552 to 1.420(P=0.613)under the dominant,additive,and recessive models,respectively.For the-137G/C polymorphism,the adjusted odds ratios and 95%confidence intervals were 1.571,1.068 to 2.311(P=0.022);1.467,1.086 to 1.980(P=0.012);and 1.815,0.901 to 3.656(P=0.095)under the dominant,additive,and recessive models,respectively.Moreover,regardless of the model used,we found no statistical difference in distribution frequency between the active and quiescent states of TA for the-607C/A(P=0.355,0.631,and 0.705,respectively)and-137G/C polymorphisms(P=0.205,0.385,and 0.208,respectively).Conclusions:The IL18-607C/A gene polymorphism may decrease the risk of TA,and thus is a protective factor,whereas-137G/C may increase the risk of TA,and thus is a risk factor.However,neither polymorphism was related to activity(active vs.quiescent)of TA.

Single Nucleotide Polymorphism rs10919543 in FCGR2A/ FCGR3A Region Confers Susceptibility to Takayasu Arteritis in Chinese Population

Background： Takayasu arteritis （TA） is a rare inflammatory arteriopathy of unknown etiology. The aim of this study was to investigate the genetic susceptibility to TA in a Chinese population. Methods： Four single nucleotide polymorphisms （SNPs） those locate in the IL12B region （rs56167332）, the MLX region （rs665268）, the FCGR2A/FCGR3A locus （rsi0919543）, and the HLA-B/M1CA locus （rs12524487）, associated with TA in different population, were genotyped in 123 Chinese TA patients and 147 healthy controls from January 2013 to August 2014. A Chi-square test was used to test for genotype/allele frequencies variants. Results： Among the four SNPs, rs 10919543 was found to be significantly associated with TA in the studied population. The GG genotype of rs 10919543 at the FCGR2A/FCGR3A locus is a high risk factor （odds ratio [OR] = 6.532, 95% confidence interval [C1] = 2.402 - 17.763, P 〈 0.001 ） for TA. Among TA patients, the level of eosinophil granulocytes （Eos） in the peripheral blood was observed to be higher in the GG group of rs 10919543 （n = 23, Eos = 0. I 1 [0.08, 0.17] x 109/L） than the GA ＋ AA group （n = 100, Eos = 0.08 [0.05, 0.13] 10/L, P = 0.028）. No correlation between the genotypes of the other three SNPs and TA patients was observed. Conclusions： Our findings revealed unique genetic pattern in Chinese TA patients that may be partly responsible for the higher risk of TA in this population. FCGR2A/FCGR3A-related immune disorder might contribute to the etiology of TA.