Immunohistochemical expression of retinoblastoma and phospho-retinoblastoma protein in sheep lung exposed to fluoro-edenite fibers.
The immunohistochemical expression of retinoblastoma protein (Rb) and its phosphorylated form (pRb) was investigated in an in vivo sheep model, i.e., lung tissue exposed to asbestos-like fibers. Rb is a phosphoprotein with a central role in controlling the cell cycle, cell growth regulation, differentiation, and apoptosis. pRb functions as a checkpoint in the G(1) phase, favoring cell growth, while the hypophosphorylated form (Rb) not only promotes cell-cycle arrest and a return to the G(1) phase, but also appears to be a key player in most instances of apoptosis. pRb overexpression was detected in alveolar epithelium and the interstitium, especially close to the fluoro-edenite fibers, whereas Rb immunostaining was faint or absent. The data suggest that the altered balance between pRb and Rb expression may be a programmed response to protect the organism against uncontrolled cell proliferation.
Musumeci
Giuseppe
G
Department of Anatomy, Diagnostic Pathology, Forensic Medicine, Hygiene and Public Health, University of Catania, Via S. Sofia 87, 95123, Catania, Italy. g.musumeci@unict.it
Loreto
Carla
C
Cardile
Venera
V
Carnazza
Maria Luisa
ML
Martinez
Giuseppina
G
D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D017636:Asbestos, Amphibole / Q000633:toxicity*; D001195:Asbestosis / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics; D049109:Cell Proliferation / Q000187:drug effects; D002471:Cell Transformation, Neoplastic / Q000187:drug effects / Q000378:metabolism*; D004195:Disease Models, Animal; D005260:Female; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology; D010766:Phosphorylation / Q000187:drug effects / Q000502:physiology; D020545:Respiratory Mucosa / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D016160:Retinoblastoma Protein / Q000096:biosynthesis*; D034561:Sheep, Domestic
D017636:Asbestos, Amphibole; D016160:Retinoblastoma Protein; C492470:fluor-edenite