CD4+ T cells and TGFβ1/MAPK signal pathway involved in the valvular hyperblastosis and fibrosis in patients with rheumatic heart disease

The aim of this study was to investigate the roles of CD4⁺ T cells and transforming growth factor beta (TGFβ1) in the pathological process of valvular hyperblastosis and fibrosis of patients with rheumatic heart disease (RHD). A total of 151 patients were enrolled, among whom, 78 patients were with RHD, and 73 were age and gender matched RHD negative patients. Blood samples and valve specimens were collected for analysis. Pathological changes and collagen fibers contents of valves were analyzed using HE and Masson staining. Percentage of peripheral blood CD4⁺ T cells was tested through flow cytometry. TGFβ1 level in serum were identified by ELISA. CD4⁺ T cells infiltration and expression of TGFβ1, p-p38, p-JNK, p-ERK in valves were detected by immunohistochemistry. The mRNA and protein levels of p38, JNK, ERK, TGFβ1, I-collagen and α-SMA were detected by qRT-PCR and western blotting, respectively. The heart valve tissues of RHD patients showed higher degrees of fibrosis, calcification and lymphocytes infiltration, which were mainly CD4⁺ T cells. In addition, compared with control group, RHD patients had more total CD4⁺ T cells in peripheral blood and valve tissues. Expression of TGFβ1, phosphorylation of JNK and p38, and synthesis of I-collagen in valve tissues of RHD patients were also significantly increased. Furthermore, we found a strong positive correlation between TGFβ1 expression and phosphorylation of JNK and p38. CD4⁺ T cells, and fibrogenic cytokine TGFβ1, which activate the intracellular MAPK signaling pathway may participate in the fibrosis of heart valve in RHD patients.

Sickening or Healing the Heart? The Association of Ficolin-1 and Rheumatic Fever

Rheumatic fever (RF) and its subsequent progression to rheumatic heart disease (RHD) are chronic inflammatory disorders prevalent in children and adolescents in underdeveloped countries, and a contributing factor for high morbidity and mortality rates worldwide. Their primary cause is oropharynx infection by Streptococcus pyogenes, whose acetylated residues are recognized by ficolin-1. This is the only membrane-bound, as well as soluble activator molecule of the complement lectin pathway (LP). Although LP genetic polymorphisms are associated with RF, FCN1 gene's role remains unknown. To understand this role, we haplotyped five FCN1 promoter polymorphisms by sequence-specific amplification in 193 patients (138 with RHD and 55, RF only) and 193 controls, measuring ficolin-1 serum concentrations in 78 patients and 86 controls, using enzyme-linked immunosorbent assay (ELISA). Patients presented lower ficolin-1 serum levels (p < 0.0001), but did not differ according to cardiac commitment. Control's genotype distribution was in the Hardy-Weinberg equilibrium. Four alleles (rs2989727: c.-1981A, rs10120023: c.-542A, rs10117466: c.-144A, and rs10858293: c.33T), all associated with increased FCN1 gene expression in whole blood or adipose subcutaneous tissue (p = 0.000001), were also associated with increased protection against the disease. They occur within the *3C2 haplotype, associated with an increased protection against RF (OR = 0.41, p < 0.0001) and with higher ficolin-1 levels in patient serum (p = 0.03). In addition, major alleles of these same polymorphisms comprehend the most primitive *1 haplotype, associated with increased susceptibility to RF (OR = 1.76, p < 0.0001). Nevertheless, instead of having a clear-cut protective role, the minor c.-1981A and c.-144A alleles were also associated with additive susceptibility to valvar stenosis and mitral insufficiency (OR = 3.75, p = 0.009 and OR = 3.37, p = 0.027, respectively). All associations were independent of age, sex or ethnicity. Thus, minor FCN1 promoter variants may play a protective role against RF, by encouraging bacteria elimination as well as increasing gene expression and protein levels. On the other hand, they may also predispose the patients to RHD symptoms, by probably contributing to chronic inflammation and tissue injury, thus emphasizing the dual importance of ficolin-1 in both conditions.

IL-10 genetic polymorphisms were associated with valvular calcification in Han, Uygur and Kazak populations in Xinjiang, China

OBJECTIVE

Valvular calcification occurs via ongoing endothelial injury associated with inflammation. IL-10 is an anti-inflammatory cytokine and 75% of the variation in IL-10 production is genetically determined. However, the relationship between genetic polymorphisms of IL-10 and valvular calcification has not been studied. The objective of this study was to investigate the association between valvular calcification and IL-10 genetic polymorphisms in the Han, Uygur and Kazak populations in China.

PATIENTS AND METHODS

All of the participants were selected from subjects participating in the Cardiovascular Risk Survey (CRS) study. The single nucleotide polymorphisms (SNPs) rs1800871 and rs1800872 of the IL-10 gene were genotyped using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Three independent case-control studies involving the Han population, the Uygur population and the Kazak population were used in the analysis.

RESULTS

For the Han and Kazak populations, rs1800871 was found to be associated with valvular calcification in the recessive model, and the difference remained statistically significant following multivariate adjustment (p<0.001, p=0.031, respectively). For the Han, Uygur and Kazak populations, rs1800872 was found to be associated with valvular calcification in the dominant model, and the difference remained statistically significant following multivariate adjustment (p<0.001, p=0.009, and p=0.023,respectively).

CONCLUSION

Both rs1800871 and rs1800872 of the IL-10 gene are associated with valvular calcification in the Han and Kazak populations in China. Rs1800872 is also associated with valvular calcification in the Uygur population.

Relation between Sympathetic Overactivity and Left Atrial Spontaneous Echo Contrast in Patients with Mitral Stenosis and Sinus Rhythm

BACKGROUND

Spontaneous echo contrast (SEC) is common in patients with mitral stenosis (MS) and presence of SEC in left atrium (LA) is associated with a higher risk of thromboembolism. Recently, an increase in activation of platelets was demonstrated in patients with SEC raising the hypothesis that platelets are involved in the pathogenesis of SEC. In this study, we evaluated effects of autonomic nervous system activity on SEC formation in patients with rheumatic MS and sinus rhythm by heart rate variability analysis.

METHODS AND RESULTS

Twenty-six patients with LASEC were compared with 28 patients without LASEC. Mean heart rate, low frequency (LF) and low frequency/high frequency (LF/HF) ratio were significantly higher, standard deviation of all NN (SDNN), root mean square of successive differences (RMSSD), number of NN intervals that differed by more than 50 ms from adjacent interval divided by the total number of all NN intervals (PNN50) and high frequency (HF) values were lower in the patients with LASEC. A standard deviation of all NN intervals <90ms separated the patients with LASEC from control subjects with a sensitivity of 77% and specificity of 90%; a low frequency >79.5 with a sensitivity of 92% and specificity of 90; a low frequency/high frequency ratio >3.7 with a sensitivity of 96% and specificity of 90%. A left atrial diameter >4.3 cm increased the LASEC formation by 3.0 folds, HR >78 beats/min by 6.4 folds, standard deviation of all NN intervals <90 ms by 9.2 folds, a low frequency/high frequency ratio >3.7 by 6.4 folds, sP-selectin>142 by 5.8 folds. Variables affecting sP-selectin levels were LA diameter, mitral valve area, transmitral mean gradient, left ventricular ejection fraction, the presence of mitral regurgitation, HR, standard deviation of all NN intervals, low frequency, high frequency and low frequency/high frequency ratio.

CONCLUSION

Sympathetic overactivity and reduced heart rate variability are important determinants for LASEC formation and increased s-P selectin levels. Therefore, platelet activation via increased sympathetic activity may play an important role in pathogenesis of LASEC.

Stenotic aortic and mitral valves in three adult brothers with arthrogryposis multiplex congenita

Three brothers with arthrogryposis multiplex congenita survived into adulthood. In their fourth decade, the clinical course for each brother became complicated by severe stenoses of their aortic and mitral valves. One brother died suddenly, and the remaining 2 developed heart failure. requiring valvular replacement.

Down-regulation of sarcolipin mRNA expression in chronic atrial fibrillation

BACKGROUND

Abnormal intracellular Ca2+ homeostasis is an important modulator of chronic atrial fibrillation. Sarcolipin, a homologue of phospholamban, is specifically expressed in the atria, and may play an important role in modulating intracellular Ca2+ homeostasis in the atria. The aim of this study was to investigate the expression of sarcolipin mRNA in the atrial myocardium of patients with chronic atrial fibrillation.

METHODS

We analyzed the expression of sarcolipin, phospholamban, cardiac calsequestrin and sodium calcium exchanger mRNAs in the right atrial myocardium from nine patients with mitral valvular disease with atrial fibrillation (MVD/AF), nine patients with MVD who had normal sinus rhythm (MVD/NSR), and 10 control patients with normal sinus rhythm who received open heart surgery (controls). The expression of mRNA was measured using the ABI PRISM 7700 Sequence Detection System (Applied Biosystems, Foster City, CA).

RESULTS

Relative expression levels of sarcolipin mRNA were significantly lower in MVD/AF (0.60 +/- 0.11) than in either MVD/NSR (1.28 +/- 0.17, P < 0.01) or controls (1.10 +/- 0.10, P < 0.05). The expression levels of sarcolipin mRNA were significantly lower in the group with high values for right atrial pressure. The expression levels of phospholamban, cardiac calsequestrin and sodium calcium exchanger mRNAs were comparable among all three groups.

CONCLUSIONS

Chronic electrical and mechanical overload decreased the expression of sarcolipin mRNA in the right atrial myocardium in patients with chronic atrial fibrillation. Down-regulation of sarcolipin mRNA may be part of atrial fibrillation-induced atrial remodelling.

Association between transforming growth factor-beta1 gene C-509T and T869C polymorphisms and rheumatic heart disease

BACKGROUND

Scarring and collagen deposition in the valves and destruction of myocytes may result from the combined effects of a smoldering rheumatic process and a constant trauma to the mitral valve or aortic valve by the turbulent flow in rheumatic heart disease (RHD). Transforming growth factor-beta1 (TGF-beta1) may be responsible for the increased valvular fibrosis and calcification in the pathogenesis of RHD. However, the role of TGF-beta1 genetic variant in RHD has not been studied. This case-controlled study was carried out to investigate the possible relationship between the TGF-beta1 gene C-509T and T869C polymorphisms and RHD among the Chinese population in Taiwan.

METHODS

A group of 115 patients with RHD documented by using echocardiography and 100 age- and sex-matched healthy control patients were studied. TGF-beta1 gene C-509T and T869C polymorphisms were identified with polymerase chain reaction-based restriction analysis.

RESULTS

A significant difference was seen in the distribution of genotypes between patients with RHD and control patients for either TGF-beta1 C-509T polymorphism (P <.0001) or T869C polymorphism (P <.0001). The frequency of TGF-beta1 C-509T CC genotype was lower in the RHD group than in the control group (chi2 = 19.05, P <.0001), which suggests that this genotype may confer protective effects against RHD. A significant difference was seen in the distribution of allelic frequency between patients with RHD and control patients for TGF-beta1 T869C polymorphism (P =.04). The odds ratio (OR) for risk of RHD associated with TGF-beta1 T869C T allele was 1.49 (95% CI, 1.02-2.19). Further categorization of patients with RHD into mitral valve disease and combined valve disease subgroups revealed no statistical difference in these gene polymorphisms when compared with the 2 subgroups.

CONCLUSIONS

Patients with RHD have a lower frequency of TGF-beta1 C-509T CC genotype and a higher frequency of T869C T allele, which supports a role for the TGF-beta1 gene C-509T and T869C polymorphisms in determining the risk/protection of RHD in Taiwan Chinese patients.

Association Between Apolipoprotein E Alleles and Calcific Valvular Heart Disease

Background— Studies on apolipoprotein E (apoE) alleles have reported an increased risk of coronary heart disease in patients with the apoE4 allele. Given the risk factor and histological similarities between coronary and calcific valvular heart disease (aortic stenosis [AS] and mitral annular calcification [MAC]), we postulated that apoE alleles might be associated with the development of these valvular lesions.

Methods and Results— We evaluated the association between apoE alleles and calcific valvular lesions in 802 patients undergoing transthoracic echocardiography using logistic regression analyses. No difference was noted in genotype distribution ( P =0.59) or prevalence of apoE4 between those with or without MAC (30% versus 27%, respectively; P =0.57). Compared with patients without AS, the genotype distribution of patients with AS differed significantly ( P =0.03), with increasing prevalences of the apoE 4 allele (27% in those without versus 40% in those with AS; P =0.01). In multivariate analyses adjusting for age, gender, low-density lipoprotein cholesterol levels, and coronary artery disease, increasing age and the apoE4 allele were significant independent predictors of AS (odds ratio, 1.94; 95% confidence interval, 1.01 to 3.71; P =0.046), whereas the apoE4 allele was not predictive of MAC.

Conclusions— These findings support extension of the importance of the apoE4 allele beyond atherosclerosis and Alzheimer’s disease to calcific AS.

Cardiac septal and valvular dysmorphogenesis in mice heterozygous for mutations in the homeobox gene Nkx2-5

Heterozygous mutations in the cardiac homeobox gene, NKX2-5, underlie familial cases of atrial septal defect (ASD) with severe atrioventricular conduction block. In this study, mice heterozygous for Nkx2-5-null alleles were assessed for analogous defects. Although ASD occurred only rarely, atrial septal dysmorphogenesis was evident as increased frequencies of patent foramen ovale and septal aneurysm, and decreased length of the septum primum flap valve. These parameters were compounded by genetic background effects, and in the 129/Sv strain, septal dysmorphogenesis bordered on ASD in 17% of Nkx2-5 heterozygotes. In a proportion of neonatal heterozygotes, as well as in adults with ASD, we found that the size of the foramen ovale was significantly enlarged and altered in shape, potentially exposing the normally thin septum primum to excessive hemodynamic forces. Therefore, defective morphogenesis of the septum secundum may be one contributing factor in the generation of patent foramen ovale, septal aneurysm, and certain ASDs. Mild prolongation of P-R interval in females and an increased frequency of stenotic bicuspid aortic valves were also features of the Nkx2-5 heterozygous phenotype. Our data demonstrate that the complex effects of Nkx2-5 haploinsufficiency in mice are weaker but convergent with those in humans. As in the mouse, the phenotype of human NKX2-5 mutations may be modulated by interacting alleles.

Autopsy findings in the Wolcott-Rallison syndrome

Wolcott-Rallison syndrome is a rare autosomal recessive condition characterized by diabetes mellitus arising in early infancy and multiple epiphyseal dysplasia. To date, nine cases have been described in the world literature. We report an affected girl who died at the age of 4 years and on whom a full autopsy was performed. In addition to neonatal diabetes mellitus and epiphyseal dysplasia, this child had mental retardation and recurrent episodes of self-limiting hepatic failure. Autopsy revealed severe pancreatic hypoplasia and markedly abnormal pancreatic histology, while histology of the bone was consistent with epiphyseal dysplasia. There was laryngeal stenosis and pulmonary hypoplasia. The heart was enlarged with mitral value dysplasia and stenosis, left atrial dilatation, left ventricular hypertrophy, and endocardial fibroelastosis. Examination of the central nervous system showed arrhinencephaly and cerebellar cortical dysplasia. The liver showed minor histological abnormalities but no features were present to account for the recurrent hepatic failure. In addition to Wolcott-Rallison syndrome this child had a deletion at 15q11-12 in 65% of her cells.

Frequency of D8/17 B lymphocyte alloantigen in north Indian patients with rheumatic heart disease

Ninety patients with rheumatic heart disease and 50 age- and sex-matched healthy human volunteers representing a North Indian population were typed for the B cell alloantigen D8/17 using a monoclonal antibody and a single step immunofluorescence technique. This alloantigen was expressed in 66.44% patients with RHD as compared with 14% of the normal population. A high relative risk (RR = 11.13) indicated a strong association of D8/17 B cell alloantigen with rheumatic heart disease. Increase in the frequency of the marker was observed with increasing age up to the fifth decade (40-49 years) in these patients. However, the frequency of this alloantigen, in the present study, in North Indian patients with rheumatic heart disease is lower than that reported in the American population.

Left ventricular beta 1 and beta 2 adrenoceptor mRNA expression in normal and volume overloaded human heart

STUDY OBJECTIVE

The aim was to determine gene expressions of beta 1 and beta 2 adrenoceptor subtypes (BAR-1, BAR-2) in normal and volume overloaded human heart.

DESIGN

Tissue mRNA levels were determined by excess solution hybridisation using 35S-UTP labelled BAR-1 and BAR-2 cRNA probes.

MATERIAL

Atrium, right and left ventricular subendocardium, and papillary muscle from donor hearts and papillary muscle from patients operated for mitral stenosis and mitral regurgitation were studied.

MEASUREMENTS AND MAIN RESULTS

The basal levels of myocardial BAR-1 and BAR-2 mRNA expression were similar to the levels in human adipose tissue that have been reported previously from our laboratory (10-15 amol mRNA.micrograms-1 total nucleic acids). No differences in BAR-1 and BAR-2 mRNA expression were observed between various parts of the normal heart. In papillary muscle, BAR-1 and BAR-2 mRNA levels were 8.8 (SEM 5.1) and 10.2(6.6) amol.micrograms-1 total nucleic acids, respectively. Furthermore, no differences in BAR mRNA expression were observed between myocardium subjected to mitral stenosis as compared to normal myocardium. On the other hand, patients with mitral regurgitation expressed significantly lower levels of both BAR-1 and BAR-2 mRNA, at 4.8(1.0) (p less than 0.05) and 2.6(1.1) (p less than 0.001) amol.micrograms-1 total nucleic acids, respectively. The ratio BAR-1/BAR-2 mRNA was higher (p less than 0.01) in mitral regurgitation than in the normal heart.

CONCLUSIONS

Myocardium from different parts of the normal human heart, where different pressure work is generated, express similar levels of BAR-1 and BAR-2 mRNA. With volume load a significant decrease in BAR mRNA levels was observed, which was more marked for BAR-2 mRNA. This difference in specific mRNA levels in patients with mitral regurgitation indicates an independent regulation of the expression of these two receptor subtypes.

[Familial occurrence of acquired heart valve defect]

A report is given on a family examination, issuing from 213 persons with an acquired valvular defect for the establishment of further cases on altogether 783 relations of the direct line. In 19 families other 21 patients with an acquired valvular defect were found; this corresponds to a share of 2.7 % of the relations examined and 8.1% of the families affected, respectively. The result repays the expenditure and, apart from this, leads to an essential furthering of the confidence between physician, patient and family as the smallest social unity for prophylaxis, diagnostics, therapy and metaphylaxis of chronic diseases.