Substance P is associated with heart enlargement and apoptosis in murine dilated cardiomyopathy induced by Taenia crassiceps infection.
Dilated cardiomyopathy (degeneration of heart muscle and heart enlargement) is an important cause of heart failure among young adults. Dilated cardiomyopathy may be a complication during or after various viral, bacterial, or parasitic diseases. Substance P (SP) is a neurotransmitter that is involved in the pathogenesis of various diseases. To determine whether SP is associated with cardiac changes in murine cysticercosis, we compared heart-weight to body-weight ratio, cardiac pathology, cardiomyocyte size, and cardiac-apoptosis (TUNEL assay) in hearts from Taenia crassiceps-infected (wild-type vs. SP-knockout) mice. We noted that, as compared with control uninfected wild-type mice, elevated protein levels of SP and its receptor as studied by ELISA or immunohistochemistry, respectively, were elevated in the hearts of parasite-infected wild-type mice. The heart-weight to body-weight ratios were significantly higher in the parasite-infected wild-type mice versus those of the infected SP-knockout mice. Furthermore, wild-type infected mice developed dilated cardiomyopathy with increased chamber size of both ventricles, decreased ventricular wall thickness, compensatory cardiomyocyte hypertrophy, and increased cardiac apoptosis. This cardiac pathology did not develop in mice lacking SP activity (i.e., in infected SP knockout mice) or in uninfected mice. These data indicate that SP is associated with cardiac changes in an animal model of parasitic dilated cardiomyopathy.
D'Souza
Melinda
M
Department of Medicine (Section of Infectious Disease), Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA.
Garza
M Armandina
MA
Xie
Min
M
Weinstock
Joel
J
Xiang
Qian
Q
Robinson
Prema
P
D000818:Animals; D017209:Apoptosis; D006332:Cardiomegaly / Q000469:parasitology / Q000473:pathology / Q000503:physiopathology*; D002311:Cardiomyopathy, Dilated / Q000469:parasitology / Q000473:pathology / Q000503:physiopathology*; D003551:Cysticercosis / Q000469:parasitology / Q000473:pathology / Q000503:physiopathology*; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009206:Myocardium / Q000473:pathology*; D018377:Neurotransmitter Agents / Q000235:genetics / Q000378:metabolism*; D013373:Substance P / Q000235:genetics / Q000378:metabolism*; D013621:Taenia / Q000472:pathogenicity*; D013622:Taeniasis / Q000469:parasitology / Q000473:pathology / Q000503:physiopathology
D018377:Neurotransmitter Agents; D013373:Substance P