OBJECTIVETo investigate whether valvular expression of macrophage and its subsets and correlative cytokines of mitral valve are altered in patients with rheumatic valvular disease.

METHODSThe mitral valvular leaflets of 15 rheumatic valvular disease patients were included as the test group, and 7 patients of terminal stage cardiomyopathy as the control. The immunostain of CD68, inducible nitric oxide synthase (iNOS) and CD163 were applied to mark the total macrophages, M1 and M2, respectively. The expression of endothelial nitric oxide synthase (eNOS), IL-10, Arg-1, macrophage-colony stimulating factor (M-CSF) were compared respectively in two groups.

RESULTSThe angiogenesis was enormous in the test, whereas the cell proliferation was scanty. Compared with the control, CD68 positive macrophages were markly expressed in the test (4.2 ± 2.0 vs. 3.2 ± 2.3; Z = -3.981, P = 0.000), also the iNOS positive M1 subsets (3.4 ± 1.7 vs. 1.2 ± 1.0; Z = -4.015, P = 0.000). The expression level of CD163 positive macrophages was lower in the test (1.2 ± 1.0 vs. 2.3 ± 1.8; Z = -8.602, P = 0.000). The expression of eNOS was higher in the rheumatic valve disease (4.9 ± 1.1 vs. 1.8 ± 1.1), but the expression levels of Arg-1 (1.0 ± 1.0 vs. 3.3 ± 1.3) and IL-10 (2.1 ± 1.2 vs. 4.9 ± 1.4) were lower (Z = -8.867 to -5.344, P = 0.000). The expression of M-CSF was lower in test (2.0 ± 1.4 vs. 4.3 ± 0.9; Z = -2.741, P = 0.006).

CONCLUSIONSThe infiltration of M1 macrophages plays an important role in the progression of rheumatic mitral valve disease. It fulfills the pro-inflammation by up-regulating the expression of eNOS. Inversely, it suppresses the expression of IL-10, Arg-1 to relieve the inflammatory action. In according with the down-regulated level of M-CSF, the polarization from M1 macrophages into M2 is depressed, and the inflammation induced by M1 is sustained.

Adult ; Aged ; Female ; Heart Valve Diseases ; pathology ; Humans ; Interleukin-10 ; metabolism ; Macrophage Colony-Stimulating Factor ; metabolism ; Macrophages ; metabolism ; Male ; Middle Aged ; Mitral Valve ; Nitric Oxide Synthase Type III ; metabolism ; Rheumatic Heart Disease ; pathology

For the purpose of determining the pathogenic role of transforming growth factor-beta1 (TGF-beta1) in the mechanism of chronic rheumatic heart disease, we evaluated the expression of TGF-beta1, proliferation of myofibroblasts, and changes in extracellular matrix components including collagen and proteoglycan in 30 rheumatic mitral valves and in 15 control valves. High TGF-beta1 expression was identified in 21 cases (70%) of rheumatic mitral valves, whereas only 3 cases (20%) of the control group showed high TGF-beta1 expression (p<0.001). Additionally, increased proliferation of myofibroblasts was observed in the rheumatic valves. High TGF-beta1 expression positively correlated with the proliferation of myofibroblasts (p=0.004), valvular fibrosis (p< 0.001), inflammatory cell infiltration (p=0.004), neovascularization (p=0.007), and calcification (p<0.001) in the valvular leaflets. The ratio of proteoglycan to collagen deposition inversely correlated with TGF-beta1 expression in mitral valves (p=0.040). In conclusion, an ongoing inflammatory process, the expression of TGF-beta1, and proliferation of myofibroblasts within the valves have a potential role in the valvular fibrosis, calcification, and changes in the extracellular matrix that lead to the scarring sequelae of rheumatic heart disease.
Adult ; Aged ; Chronic Disease ; Collagen/metabolism ; Female ; Fibrosis ; Humans ; Immunohistochemistry ; Male ; Middle Aged ; Mitral Valve/*pathology ; Proteoglycans/metabolism ; Rheumatic Heart Disease/*metabolism/pathology ; Transforming Growth Factor beta1/analysis/*physiology

OBJECTIVETo investigate the effect of hepatocyte growth factor (HGF) and transforming growth factor-β(1) (TGFβ(1)) on the expression of α-smooth muscle actin (α-SMA) and collagen I in human atrial fibroblast in vitro, and to explore the possible molecular mechanism of atrial fibrosis in patients with atrial fibrillation (AF).

METHODSHuman atrial fibroblast, isolated from aseptic right atrial appendage tissues of 10 sinus rhythm (SR) and 10 chronic atrial fibrillation (CAF) patients, were cultured with HGF and TGFβ(1). mRNA expressions of collagen I and α-SMA were detected by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR), the protein expression of α-SMA was determined by immunofluorescence and Western blot.

RESULTS(1) Compared with SR group, left atrium was significantly dilated in CAF group (t = 2.692, P < 0.05), the mRNA expression of collagen I and α-SMA of atrial fibroblasts were significantly upregulated (all P < 0.01), mRNA expression of collagen I was positively correlated with left atrial dimension (LAD) (r = 0.836, P = 0.014), AF duration (r = 0.739, P = 0.045) and α-SMA mRNA level (r = 0.886, P = 0.012). (2) Compared with SR group, the expression of α-SMA protein in CAF atrial fibroblasts were significantly increased (P < 0.01). (3) TGFβ(1) further stimulated while HGF significantly attenuated the expression of collagen I and α-SMA in CAF atrial fibroblasts (all P < 0.01).

CONCLUSIONSIncreasing expression of collagen I and α-SMA in human atrial fibroblasts might promote atria remodeling leading to the development and sustaining of AF. HGF is involved in the negative regulation on the expression of α-SMA and collagen I.

Actins ; metabolism ; Adolescent ; Adult ; Atrial Fibrillation ; metabolism ; pathology ; Cells, Cultured ; Collagen Type I ; metabolism ; Female ; Fibroblasts ; drug effects ; metabolism ; Fibrosis ; Gene Expression ; Heart Atria ; cytology ; metabolism ; pathology ; Hepatocyte Growth Factor ; pharmacology ; Humans ; Male ; Middle Aged ; RNA, Messenger ; genetics ; Rheumatic Heart Disease ; metabolism ; pathology ; Transforming Growth Factor beta1 ; pharmacology ; Young Adult