Expression of non-muscle myosin heavy chain in rat heart after immunosuppressive treatment.
Myosins constitute a large family of molecular motors, hydrolyzing ATP and producing cellular movement. To date, a large number of novel isoforms have been found in muscle and non-muscle cells. Among non-muscle myosins, non-muscle myosin heavy chain (NMHC) II-A and II-B have been well characterized. An additional member of NMHC II-B, with a molecular weight of 220 kDa, was recently identified in bovine skeletal muscle. NMHC II-B proteins, in particular, have been suggested to be a useful early molecular marker for the detection of pathological conditions during acute or chronic organ rejection in which fibrotic changes occur. Since it is known that treatment with cyclosporine A (CsA), an immunosuppressive drug successfully used for preventing organ rejection and autoimmune diseases, is often associated with several side effects (hypertension and nephrotoxicity), the aims of this study were: (1) to demonstrate the homology of the new NMHC protein (220 kDa) in other mammalian species, such as Wistar rats; (2) to evaluate, by morphological and immunohistochemical studies, the possible changes induced by CsA treatment in NMHC protein (220 kDa) cellular localization and/or in its expression levels in myocardial tissue. First of all, our results showed a greater homology of the new NMHC within the same isoforms across species and between isoforms in the same specie; moreover, we observed that this protein increased following CsA treatment. This could be explained as a tentative of cardiac tissue to maintain the structural integrity of intercalated disks and so the contraction/relaxation process.
Rezzani
Rita
R
Division of Human Anatomy, Department of Biomedical Sciences and Biotechnologies, University of Brescia, V.le Europa 11, 25123, Brescia, Italy. rezzani@med.unibs.it
Pompili
Elena
E
Agostini
Cristina
C
Buffoli
Barbara
B
Bonomini
Francesca
F
Nori
Stefania
S
Fumagalli
Lorenzo
L
Bianchi
Rossella
R
D000818:Animals; D015153:Blotting, Western; D016572:Cyclosporine / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects*; D007150:Immunohistochemistry; D007166:Immunosuppressive Agents / Q000494:pharmacology; D008297:Male; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology; D018995:Myosin Heavy Chains / Q000378:metabolism*; D024501:Nonmuscle Myosin Type IIB / Q000378:metabolism*; D020033:Protein Isoforms / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
D007166:Immunosuppressive Agents; D020033:Protein Isoforms; D016572:Cyclosporine; D024501:Nonmuscle Myosin Type IIB; C103815:nonmuscle myosin type IIB heavy chain; D018995:Myosin Heavy Chains