title: Suppression of insulin-like3 receptor reveals the role of β-catenin and Notch signaling in gubernaculum development.
abstract: During male development, the testes move from a high intraabdominal position and descend into the scrotum. The gubernaculum, an inguinoscrotal ligament connecting the testis to the lower abdomen, is believed to play a critical role in this process. The first stage of testicular descent is controlled by insulin like3 hormone (INSL3), produced in testicular Leydig cells. Deletion of Insl3 or its receptor, Rxfp2, in mice causes cryptorchidism. We produced Cre/loxP regulated shRNA transgenic mice targeting RXFP2 expression. We have shown that the transgene was able to reduce Rxfp2 gene expression and thus behaved as a hypomorphic allele of Rxfp2. Variable degrees of uni- and bilateral cryptorchidism was detected in males with the activated shRNA transgene on an Rxfp2+/- background. Conditional suppression of Rxfp2 in the gubernaculum led to cryptorchidism. Gene expression analysis of a mutant cremasteric sac using Illumina microarrays indicated abnormal expression of a significant number of genes in Wnt/β-catenin and Notch pathways. We have demonstrated profound changes in the expression pattern of β-catenin, Notch1, desmin, and androgen receptor (AR), in Rxfp2-/- male embryos, indicating the role of INSL3 in proliferation, differentiation, and survival of specific cellular components of the gubernaculum. We have shown that INSL3/RXFP2 signaling is essential for myogenic differentiation and maintenance of AR-positive cells in the gubernaculum. Males with the deletion of β-catenin or Notch1 in the gubernacular ligament demonstrated abnormal development. Our data indicates that β-catenin and Notch pathways are potential targets of INSL3 signaling during gubernacular development.
authors.affiliation: Department of Human Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, 11200 SW 8th Street, Miami, FL 33199, USA.
authors.forename: Elena M
authors.initials: EM
authors.lastname: Kaftanovskaya
authors.forename: Shu
authors.initials: S
authors.lastname: Feng
authors.forename: Zaohua
authors.initials: Z
authors.lastname: Huang
authors.forename: Yingchun
authors.initials: Y
authors.lastname: Tan
authors.forename: Agustin M
authors.initials: AM
authors.lastname: Barbara
authors.forename: Sukhjinder
authors.initials: S
authors.lastname: Kaur
authors.forename: Anne
authors.initials: A
authors.lastname: Truong
authors.forename: Ivan P
authors.initials: IP
authors.lastname: Gorlov
authors.forename: Alexander I
authors.initials: AI
authors.lastname: Agoulnik
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D003456:Cryptorchidism / Q000235:genetics / Q000473:pathology; D017353:Gene Deletion; D018507:Gene Expression Regulation, Developmental; D057809:HEK293 Cells; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D008022:Ligaments / Q000254:growth & development* / Q000378:metabolism* / Q000473:pathology; D008297:Male; D051379:Mice; D008954:Models, Biological; D024510:Muscle Development; D011506:Proteins / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000378:metabolism; D011944:Receptors, Androgen / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D051880:Receptors, Notch / Q000378:metabolism*; D015398:Signal Transduction; D019076:Transgenes / Q000235:genetics; D051176:beta Catenin / Q000378:metabolism*
chemical_list: D007328:Insulin; C084797:Leydig insulin-like protein; D011506:Proteins; D034741:RNA, Small Interfering; C555886:RXFP2 protein, mouse; D011944:Receptors, Androgen; D043562:Receptors, G-Protein-Coupled; D051880:Receptors, Notch; D051176:beta Catenin