title: Effects of in vivo heregulin beta1 treatment in wild-type and ErbB gene-targeted mice depend on receptor levels and pregnancy.
abstract: Mice heterozygous (+/-) for either heregulin (HRG), ErbB2, or ErbB3 were created by gene targeting, resulting in the loss of one functional gene copy and an associated decrease in targeted protein. We examined the in vivo activity of recombinant HRG peptide, rHRG beta1 (amino acids 177 to 241), in the three heterozygous mouse lines and in wild-type (WT) mice, both pregnant and nonpregnant. Nonpregnant WT and HRG(+/-) mice of both sexes were sensitive to rHRG beta1 treatment as evidenced by a high mortality rate associated with abdominal enlargement and parietal cell loss. However, pregnant WT mice and ErbB2 and ErbB3 heterozygous mice treated with rHRG beta1 were less affected, with significantly lower mortality rates and a less severe abdominal phenotype. Histological analysis revealed extensive breast ductal hyperplasia in females of all genotypes after rHRG beta1 treatment. Hyperplasia of other epithelial tissues such as the pancreas and intestine and the growth of cardiac nerve bundles were also observed, independent of sex.
authors.affiliation: Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA.
authors.forename: S
authors.initials: S
authors.lastname: O'Shea
authors.forename: K
authors.initials: K
authors.lastname: Johnson
authors.forename: R
authors.initials: R
authors.lastname: Clark
authors.forename: M X
authors.initials: MX
authors.lastname: Sliwkowski
authors.forename: S L
authors.initials: SL
authors.lastname: Erickson
mesh_terms: D000818:Animals; D001940:Breast / Q000187:drug effects / Q000473:pathology; D004108:Dilatation, Pathologic / Q000235:genetics / Q000401:mortality; D005260:Female; D005838:Genotype; D006321:Heart / Q000187:drug effects; D006965:Hyperplasia / Q000401:mortality; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009206:Myocardium / Q000473:pathology; D020890:Neuregulin-1 / Q000235:genetics / Q000494:pharmacology*; D010179:Pancreas / Q000187:drug effects / Q000473:pathology; D010641:Phenotype; D011247:Pregnancy; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D020893:Receptor, ErbB-3 / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000494:pharmacology; D013270:Stomach / Q000187:drug effects / Q000473:pathology; D015996:Survival Rate
chemical_list: D020890:Neuregulin-1; D018719:Erb-b2 Receptor Tyrosine Kinases; D020893:Receptor, ErbB-3; D011994:Recombinant Proteins; C087230:heregulin beta1