Immunoexpression of the relaxin receptor LGR7 in breast and uterine tissues of humans and primates

TY - JOUR

T1 - Immunoexpression of the relaxin receptor LGR7 in breast and uterine tissues of humans and primates

AU - Ivell, Richard

AU - Balvers, Marga

AU - Pohnke, Yvonne

AU - Telgmann, Ralph

AU - Bartsch, Olaf

AU - Milde-Langosch, Karin

AU - Bamberger, Ana-Maria

AU - Einspanier, Almuth

PY - 2003/11/24

Y1 - 2003/11/24

N2 - BACKGROUND: The receptor for the peptide hormone relaxin has recently been identified as the heptahelical G-protein coupled receptor, LGR7. In order to generate molecular tools with which to characterize both in vivo and in vitro expression of this receptor in human and primate tissues, specific monotypic antibodies have been generated and applied to a preliminary analysis of human and primate female reproductive tissues.METHODS: Three peptide sequences were identified from the proposed open reading frame of the cloned LGR7 receptor gene, representing both extracellular and intracellular domains. Two to three rabbits were immunized for each epitope, and the resulting sera subjected to a systematic validation using cultured cells transiently transfected with a receptor-expressing gene construct, or appropriate control constructs.RESULTS: Human and monkey (marmoset, macaque) endometrium showed consistent and specific immunostaining in the stromal cells close to glands. Staining appeared to be more intense in the luteal phase of the cycle. Weak immunostaining was also evident in the endometrial epithelial cells of the marmoset. A myoma in one patient exhibited strong immunostaining in the circumscribing connective tissue. Uterine expression was supported by RT-PCR results from cultured primary endometrial and myometrial cells. Human breast tissue (healthy and tumors) consistently indicated specific immunostaining in the interstitial connective (stromal) tissue within the glands, but not in epithelial or myoepithelial cells, except in some tumors, where a few epithelial and tumor cells also showed weak epitope expression.CONCLUSIONS: Using validated monotypic antibodies recognizing different epitopes of the LGR7 receptor, and from different immunized animals, and in different primate species, a consistent pattern of LGR7 expression was observed in the stromal (connective tissue) cells of the endometrium and breast, consistent also with the known physiology of the relaxin hormone.

AB - BACKGROUND: The receptor for the peptide hormone relaxin has recently been identified as the heptahelical G-protein coupled receptor, LGR7. In order to generate molecular tools with which to characterize both in vivo and in vitro expression of this receptor in human and primate tissues, specific monotypic antibodies have been generated and applied to a preliminary analysis of human and primate female reproductive tissues.METHODS: Three peptide sequences were identified from the proposed open reading frame of the cloned LGR7 receptor gene, representing both extracellular and intracellular domains. Two to three rabbits were immunized for each epitope, and the resulting sera subjected to a systematic validation using cultured cells transiently transfected with a receptor-expressing gene construct, or appropriate control constructs.RESULTS: Human and monkey (marmoset, macaque) endometrium showed consistent and specific immunostaining in the stromal cells close to glands. Staining appeared to be more intense in the luteal phase of the cycle. Weak immunostaining was also evident in the endometrial epithelial cells of the marmoset. A myoma in one patient exhibited strong immunostaining in the circumscribing connective tissue. Uterine expression was supported by RT-PCR results from cultured primary endometrial and myometrial cells. Human breast tissue (healthy and tumors) consistently indicated specific immunostaining in the interstitial connective (stromal) tissue within the glands, but not in epithelial or myoepithelial cells, except in some tumors, where a few epithelial and tumor cells also showed weak epitope expression.CONCLUSIONS: Using validated monotypic antibodies recognizing different epitopes of the LGR7 receptor, and from different immunized animals, and in different primate species, a consistent pattern of LGR7 expression was observed in the stromal (connective tissue) cells of the endometrium and breast, consistent also with the known physiology of the relaxin hormone.

KW - Amino Acid Sequence

KW - Animals

KW - Antibodies, Monoclonal

KW - Breast

KW - Breast Neoplasms

KW - Callithrix

KW - Cells, Cultured

KW - DNA, Complementary

KW - Endometrium

KW - Female

KW - Humans

KW - Immunization

KW - Leiomyoma

KW - Macaca fascicularis

KW - Mammary Glands, Animal

KW - Membrane Proteins

KW - Molecular Sequence Data

KW - Open Reading Frames

KW - Protein Structure, Tertiary

KW - Rabbits

KW - Receptors, G-Protein-Coupled

KW - Receptors, Peptide

KW - Recombinant Fusion Proteins

KW - Relaxin

KW - Stromal Cells

KW - Transfection

KW - Uterine Neoplasms

U2 - 10.1186/1477-7827-1-114

DO - 10.1186/1477-7827-1-114

M3 - SCORING: Journal article

C2 - 14633277

VL - 1

SP - 114

ER -