Insulin-like growth factor I (IGF-I) regulates endocrine activity of the embryonic testis in the mouse

Villalpando, Irma; López-Olmos, Victoria

doi:10.1016/s0960-0760(03)00265-6

Cited by 22 publications

(16 citation statements)

References 40 publications

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“…In accordance with this proposal, we observed that T secretion increased significantly under chronic rhIGF-I stimulation in cultures, suggesting that, similar to animal models (36), IGFs regulate steroidogenesis in the human immature testis. Indeed, an elevation of StAR, P450scc and 17␣-hydroxylase mRNA expression and steroid synthesis has been reported in mouse LC (37). In agreement with these reports, our in vitro functional studies have also shown that IGF-I induced expression of P450scc protein and 3␤HSD mRNA.…”

Section: Discussionsupporting

confidence: 91%

Role of IGFs and Insulin in the Human Testis During Postnatal Activation: Differentiation of Steroidogenic Cells

et al. 2008

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Immunoexpression of IGF-I, IGF-II, type 1 IGF receptor (IGFR), insulin receptor (IR), and GH receptor (GHR) was analyzed in human testis, in three age groups (Gr): Gr1 (neonates), Gr2 (postnatal testicular activation), and Gr3 (early prepuberty). In interstitial cells, low IGF-I and GHR, but moderate IR immunoexpression was observed in all Grs. However, high expression of IGF-II in Gr1, and moderate expression of IGFR in Gr1 and Gr2 were found. In Leydig cell (LC), high expression of IGF-II, moderate expression of IGFR and GHR, and undetectable IGF-I was found. Moreover, IR was highly expressed in Gr2. The effect of IGF-I on cell proliferation (PI) and apoptosis (AI), induction of cytochrome P450 side chain cleavage (cP450scc) immunoexpression, 3␤-hydroxysteroid dehydrogenase mRNA and testosterone (T) secretion was evaluated in human testis cell cultures. IGF-I increased P450scc immunoexpression, 3␤-hydroxysteroid dehydrogenase mRNA, T secretion, and PI, but decreased AI. We propose that IGF-II, mainly through IR, is involved in functional LC differentiation. In some interstitial cells, probably in LC precursors, IGF-II/IR could be involved, among other factors, in the stimulation of PI and/or inhibition of AI, and in LC differentiation. (Pediatr Res 63: 662-666, 2008)

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Section: Discussionsupporting

confidence: 91%

Role of IGFs and Insulin in the Human Testis During Postnatal Activation: Differentiation of Steroidogenic Cells

et al. 2008

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“…Other genes involved in this process include insulin-like growth factor I, which has been previously linked to the appearance of the steroidogenic transcripts [22] and was also elevated in the testis at this stage.…”

Section: Resultsmentioning

confidence: 87%

Profiling Gene Expression During the Differentiation and Development of the Murine Embryonic Gonad1

Small

Shima

Uzumcu

et al. 2005

Biology of Reproduction

186

194

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The application of microarray technology to the study of mammalian organogenesis can provide greater insights into the steps necessary to elicit a functionally competent tissue. To this end, a temporal profile of gene expression was generated with the purpose of identifying changes in gene expression occurring within the developing male and female embryonic gonad. Gonad tissue was collected from mouse embryos at 11.5, 12.5, 14.5, 16.5, and 18.5 days postcoitum (dpc) and relative steady-state levels of mRNA were determined using the Affymetrix MGU74v2 microarray platform. Statistical analysis produced 3693 transcripts exhibiting differential expression during male and/or female gonad development. At 11.5 dpc, the gonad is morphologically indifferent, but at 12.5 dpc, transitions to a male or female phenotype are discernible by the appearance of testicular cords. A number of genes are expressed during this period and many share similar expression profiles in both sexes. As expected, the expression of two well-known sex determination genes, specifically Sry and Sox9, is unique to the testis. Beyond 12.5 dpc, differential gene expression becomes increasingly evident as the male and female tissue morphologically and physiologically diverges. This is evident by two unique waves of transcriptional activity occurring after 14.5 dpc in the male and female. With this study, a large number of transcripts comprising the murine transcriptome can be examined throughout male and female embryonic gonad development and allow for a more complete description of gonad differentiation and development.

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“…We have previously demonstrated that transcripts for Igf-1 are expressed since the beginning of testicular development at 12-18 days of gestation and that their expression increased according to age (8). Igf-1 transcripts are also found in isolated cells tested after one, two, or three days of culture (unpublished data).…”

mentioning

confidence: 80%

“…The sedimented fraction containing Sertoli cells was treated with 0.1% trypsin for 1-3 mins, and enzyme activity was inhibited. The pellet was resuspended in D-MEM cultured medium supplemented as described before (8). To synchronize cells 1 3 10 6 , Leydig and Sertoli cells were incubated with 10% of bovine fetal serum.…”

Section: Methodsmentioning

confidence: 99%

Insulin-Like Growth Factor 1 Is Expressed in Mouse Developing Testis and Regulates Somatic Cell Proliferation

Villalpando

Lira-Romero

Medina

et al. 2008

Exp Biol Med (Maywood)

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Testicular development occurs prenatally in mammals. The developmental underlying mechanism is only partially understood. The aim of the present investigation was to study the expression of the gene coding for insulin-like growth factor 1 (Igf-1) and Igf-1 type 1 receptor (Igf-1r) and their respective proteins in mouse Sertoli and Leydig cells at gestation day 12 (E12)-E18. Moreover, we sought to determine the effect of IGF-1 on the proliferation of both cell types and to establish the signal transduction mechanism involved in the IGF-1 pathway. Transcripts for the Igf-1 and Igf-1r genes were found in Sertoli and Leydig cells from E12-E18. Highest IGF-1 and IGF-Ir protein expression levels were found in both cell types at E18. Exogenous IGF-1 administration increased Sertoli and Leydig cell proliferation at E14-E18 in vitro. Inhibition of the pathway mitogen-activated extracellular signal-regulated protein kinase (MEK) 1/2 with UO126 diminished the proliferation of the Sertoli and Leydig cells in vitro. We propose that IGF-1 and IGF-1r regulate Sertoli and Leydig cell proliferation through the MEK/extracellular-signal-regulated kinase (ERK) 1/2 signal transduction pathway, leading to development and growth of the mouse embryonic testis.

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Insulin-like growth factor I (IGF-I) regulates endocrine activity of the embryonic testis in the mouse

Cited by 22 publications

References 40 publications

Role of IGFs and Insulin in the Human Testis During Postnatal Activation: Differentiation of Steroidogenic Cells

Role of IGFs and Insulin in the Human Testis During Postnatal Activation: Differentiation of Steroidogenic Cells

Profiling Gene Expression During the Differentiation and Development of the Murine Embryonic Gonad1

Insulin-Like Growth Factor 1 Is Expressed in Mouse Developing Testis and Regulates Somatic Cell Proliferation

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