Heterogeneous nuclear ribonucleoprotein-H plays a suppressive role in visceral myogenesis.
Mouse embryonic mesenchymal cells undergo spontaneous smooth muscle (SM) differentiation upon spreading/elongation in culture (Relan et al., J. Cell Biol. 147 (1999) 1341; Yang et al., Development 125 (1998) 2621; Yang et al., Development 126 (1999) 3027). Using these cells we generated a subtracted cDNA library to identify potential suppressors of SM myogenesis. One of the differentially expressed genes was heterogeneous nuclear ribonucleoprotein-H (hnRNP-H), which is involved in pre-mRNA alternative splicing. hnRNP-H was highly expressed in mesenchymal cells prior to the onset of SM differentiation, but its expression rapidly decreased in mesenchymal cells undergoing SM myogenesis. In vivo, the drop in hnRNP-H expression was restricted to visceral SM cells. Antisense oligodeoxynucleotide and antisense RNA were used to inhibit hnRNP-H synthesis in SM-differentiating mesenchymal cells and in embryonic lung explants. A decrease in hnRNP-H levels resulted in upregulation of SM-specific gene expression and increased bronchial SM development in lung explants. hnRNP-H overexpression in cell cultures had the opposite effect. These studies, therefore, indicate a novel role for hnRNP-H in the control of visceral myogenesis.
Liu
J
J
Department of Pathology, Wayne State University School of Medicine, Detroit, MI 48201, USA.
Beqaj
S
S
Yang
Y
Y
Honoré
B
B
Schuger
L
L
D017398:Alternative Splicing; D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D001980:Bronchi / Q000196:embryology; D002454:Cell Differentiation; D004847:Epithelial Cells / Q000378:metabolism; D015723:Gene Library; D034541:Heterogeneous-Nuclear Ribonucleoprotein Group F-H; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D007150:Immunohistochemistry; D008168:Lung / Q000196:embryology / Q000473:pathology; D008648:Mesoderm / Q000378:metabolism; D051379:Mice; D008813:Mice, Inbred ICR; D009130:Muscle, Smooth / Q000196:embryology*; D016376:Oligonucleotides, Antisense / Q000378:metabolism; D009924:Organ Culture Techniques; D012333:RNA, Messenger / Q000378:metabolism; D012261:Ribonucleoproteins / Q000502:physiology*; D013997:Time Factors; D014018:Tissue Distribution; D014162:Transfection
D034541:Heterogeneous-Nuclear Ribonucleoprotein Group F-H; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger; D012261:Ribonucleoproteins