beta-hexosaminidase-induced activation of p44/42 mitogen-activated protein kinase is dependent on p21Ras and protein kinase C and mediates bovine airway smooth-muscle proliferation.
Late-phase and sustained activation of p44/42(MAPK) has been reported to be a critical factor in cell mitogenesis. We therefore hypothesized that p44/42(MAPK) is involved in mannosyl-rich glycoprotein-induced mitogenesis in bovine airway smooth-muscle cells (ASMC). Treatment of adherent ASMC with beta-hexosaminidase A (Hex A, 50 nM), an endogenous mannosyl-rich glycoprotein, resulted in a late-onset (30-min) activation of p44/42(MAPK) that lasted for 4 h. Activation of p44/42(MAPK) induced by Hex A was inhibited by an 18-mer phosphorothioate-derivatized antisense oligonucleotide (1-5 microM) directed to human p44(MAPK); the mitogen-activated protein kinase kinase (MEK1) inhibitor PD98059 (5 microM); the p42(MAPK) inhibitor Tyrphostin AG-126 (0.2 microM); the farnesyl transferase inhibitors SCH-56582 (10 microM) and FPT III (10 miroM), which inhibit p21Ras activation; and Calphostin C (0.2 microM), an inhibitor of protein kinase C. These agents also inhibited Hex A-induced cell proliferation in bovine ASMC. These data suggest that Hex A activates p44/42(MAPK) in a p21Ras- and PKC-dependent manner and that this activation mediates Hex A- induced mitogenesis in bovine ASMC.
Lew
D B
DB
The Crippled Children's Foundation Research Center; and Departments of Pediatrics and Pharmacology, College of Medicine, University of Tennessee, Memphis, Tennessee, USA. dblews@pol.net
Dempsey
B K
BK
Zhao
Y
Y
Muthalif
M
M
Fatima
S
S
Malik
K U
KU
D019883:Alkyl and Aryl Transferases / Q000037:antagonists & inhibitors; D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002417:Cattle; D002455:Cell Division; D002478:Cells, Cultured; D004789:Enzyme Activation; D054818:Hexosaminidase A; D048369:MAP Kinase Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020929:Mitogen-Activated Protein Kinase Kinases; D020928:Mitogen-Activated Protein Kinases; D009130:Muscle, Smooth / Q000166:cytology / Q000187:drug effects*; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D011493:Protein Kinase C / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D016283:Proto-Oncogene Proteins p21(ras) / Q000502:physiology*; D013997:Time Factors; D014132:Trachea / Q000187:drug effects* / Q000201:enzymology; D001619:beta-N-Acetylhexosaminidases / Q000494:pharmacology*
D016376:Oligonucleotides, Antisense; D019883:Alkyl and Aryl Transferases; C064911:p21(ras) farnesyl-protein transferase; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; D011493:Protein Kinase C; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D048369:MAP Kinase Kinase 1; C482125:MAP2K1 protein, human; D020929:Mitogen-Activated Protein Kinase Kinases; D054818:Hexosaminidase A; D001619:beta-N-Acetylhexosaminidases; D016283:Proto-Oncogene Proteins p21(ras)