Expression of pro-opiomelanocortin-like gene in the testis and epididymis.

Chen, C L; Mather, Jennie P.; Morris, Patricia L.; Bardin, C. Wayne

doi:10.1073/pnas.81.18.5672

Cited by 122 publications

(55 citation statements)

References 41 publications

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“…This corroborates the limited results obtained in mammals which indicate the expression of the POMC mRNA in Leydig cells in rat and golden hamster [21], and spermatogonia and spermatocytes in mouse [22]. The presence of b-endorphin was only reported in the interstitial compartment in rat Leydig cells and macrophages [23][24][25] and human spermatozoa [26].…”

Section: Discussionsupporting

confidence: 89%

“…Among additional mediators besides local melatonergic system in photoperiodic control of testicular steroidogenesis, b-endorphin and its receptor, m-opioid receptor, was suggested in golden hamster. Indeed, an increase in the level of plasma b-endorphin [16] and a strong expression of its receptor in testes of Mesocricetus auratus [17] have been obtained under short day exposure.…”

Section: Introductionmentioning

confidence: 99%

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17β-estradiol effect on testicular β-endorphin expression in Psammomys obesus

Madani¹,

Moudilou²,

Exbrayat³

et al. 2015

Folia Histochem Cytobiol.

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Introduction. Testicular function in the sand rodent Psammomys obesus is subjected to seasonal alternations with a trigger of spermatogenesis in winter and a total quiescence which extends from late spring to summer. The aim of this study was to investigate the distribution of b-endorphin in the testis at the period of winter sexual activity and at its summer regression, and assess the effect of 17b-estradiol treatment on testicular morphology and b-endorphin expression. Material and methods. The adult males were grouped into 4 groups (rest group, sexually active group, rest treated with 17b-estradiol group and controls at sexual rest injected with olive oil, n = 5 in each group). Using anti-serum against b-endorphin, we studied its testicular expression by Western blot and cellular location by immunohistochemical (IHC) method, respectively. Results. We detected by Western blot a peptide of 3.5 kDa molecular weight corresponding to b-endorphin only in sexually resting and control males. The 17b-estradiol treatment induced a clear reduction in the b-endorphin band expression compared with the latter. These results were confirmed by the IHC analysis since b-endorphin was only observed in the testis at sexual rest and in controls, in majority of seminiferous tubules at the level of germ cells. The intensity of IHC labeling was significantly different between spermatogonia and spermatocytes I or round spermatids which revealed the strongest labeling. The intense immunoreactivity was also located in Leydig cells and highly significantly varied compared to the germ cells. The 17b-estradiol treatment decreased significantly the b-endorphin signal in germ cells but not in Leydig cells. Conclusion. The 17b-estradiol treatment induces a repressive effect on seasonal testicular endorphinergic system in P. obesus and this action targets exclusively the germ cells.

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Section: Discussionsupporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

17β-estradiol effect on testicular β-endorphin expression in Psammomys obesus

Madani¹,

Moudilou²,

Exbrayat³

et al. 2015

Folia Histochem Cytobiol.

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“…In addition to its expression in anterior pituitary corticotrophs, the POMC gene is expressed in melanotrophs of the intermediate pituitary (10,19), specific neurons of the brain (10,19), testes (7), ovaries, and placenta (6). In …”

Section: Discussionmentioning

confidence: 99%

Tissue-specific activity of the pro-opiomelanocortin gene promoter.

Trifiro¹,

Plante²,

Chamberland³

et al. 1987

Mol. Cell. Biol.

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The pro-opiomelanocortin (POMC) gene is specifically expressed in corticotroph cells of the anterior pituitary. To define the POMC promoter sequences responsible for tissue-specific expression, we assessed POMC promoter activity by gene transfer into POMC-expressing pituitary tumor cells and fibroblast L cells. The rat POMC promoter was only efficiently utilized and correctly transcribed in AtT-20 cells. 5'-End deletion analysis revealed two promoter regions required for activity in AtT-20 cells. When tested by fusion to a heterologous promoter, DNA fragments corresponding to both regions exhibited tissue-specific activity, suggesting the presence of at least two tissue-specific DNA sequence elements within the promoter. In summary, POMC promoter sequences from -480 to -34 base pairs appear sufficient to mimic the specificity of anterior pituitary expression.Control of eucaryotic transcription results from the interaction of multiple DNA sequence elements that are presumably recognized by as many trans-acting factors (reviewed in references 21 and 33). In gene transfer experiments with tissue culture cells or transgenic animals, it was shown that various DNA sequence elements are responsible for tissuespecific expression of many cellular genes (2,3,9,16,24,29,31,39,45,46). Tissue-specific sequence elements were identified in the 5'-flanking region of the genes coding for immunoglobulins (16,24,31), insulin (46), elastase (45), otl-antitrypsin (9), and many others. Some sequences conferring tissue specificity have enhancer properties and are located either upstream of the site of transcription initiation or elsewhere in the gene (1,20,37,42). In many cases, multiple DNA sequence elements are required to confer tissue specificity (8,13,16,24,31,48), includi1ag promoterproximal and -distal sequences.The pituitary gland represents an interesting system to investigate the role of tissue-specific DNA sequence elements in the expression of cell-specific genes. Pituitary hormone-secreting cells have a common embryological origin; however, each pituitary hormone gene is expressed in a distinct cell type (17). To identify DNA sequences required for tissue-specific expression in the pituitary, we studied the activity of promoter sequences present in the rat proopiomelanocortin (POMC) gene. The POMC gene is present in a single copy per haploid genome (12); it is expressed in two different pituitary cell types, the anterior pituitary corticotrophs, in which POMC is processed to adrenocorticotropin, and the pars intermedia melanotrophs, in which the same POMC protein precursor is processed to o-melanotropin (14). Regulation of POMC gene expression in these two tissues is also cell specific (18; J.-P. Gagner and J. Drouin, Mol. Endocrinol., in press), highlighting the functional and developmental differences between the two secreting cell types. MATERIALS AND METHODSPlasmid constructions. Recombinant plasmids were constructed by standard procedures (30). Plasmid DNAs used for electroporation were purified by banding twice on...

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“…In contrast, very low levels of a mRNA of approximately 800 nt in length may be expressed from a promoter within intron B, upstream of exon 3, in a wide tissue distribution. POMC peptides are found in many peripheral tissues such as testes (Chen et al 1984, Pintar et al 1984, Gizang-Ginsberg & Wolgemuth 1985, Autelitano et al 1989, ovary and placenta (Chen et al 1986), lymphoid cells (Lolait et al 1986), adrenal medulla (Evans et al 1983, and other normal and tumour tissue (Lacaze-Masmonteil et al 1987, DeBold et al 1988a, de Keyzer et al 1989. Since the peptide translation product of this shorter mRNA species lacks a signal peptide it is unlikely that the translated proteins are normally secreted (Clark et al 1990), and their role in peripheral tissues is unclear.…”

Section: Pomc Mrna Transcriptsmentioning

confidence: 99%

Proopiomelanocortin gene expression and DNA methylation: implications for Cushing's syndrome and beyond

Newell‐Price

2003

Journal of Endocrinology

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Proopiomelanocortin gene (POMC) is recognised as playing an important role in the regulation of the hypothalamo-pituitary-adrenal axis, adrenal development and obesity. POMC is activated in ACTH-dependent Cushing's syndrome. The syndrome may occur when the highly tissue-specific 5 promoter of human POMC is activated in pituitary and non-pituitary sites. Whilst the factors involved in transcription in the corticotrophs of the anterior pituitary gland are becoming well delineated, the mechanism of activation in non-pituitary sites is not fully understood. This promoter is embedded within a defined CpG island, and, in contrast to somatically expressed CpG island promoters reported to date, is methylated in normal non-expressing tissues, but is specifically unmethylated in expressing tissues, tumours and the POMC-expressing DMS-79 small-cell lung cancer cell line. Methylation in vitro is sufficient for silencing of expression. In particular, methylation near the response element for the tissuespecific POMC activator PTX1, diminishes POMC expression. Sites outside the PTX1 response element may be important for binding, and this may have implications for pituitary development. DMS-79 cells lack POMCdemethylating activity, implying that the methylation and expression patterns are likely to be set early or prior to neoplastic transformation, and that targeted de novo methylation might be a potential therapeutic strategy. It is conceivable that in POMC neurons of the hypothalamus the POMC promoter is subject to a variable density of methylation with clear implications for the signalling of satiety and obesity.

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Expression of pro-opiomelanocortin-like gene in the testis and epididymis.

Cited by 122 publications

References 41 publications

17β-estradiol effect on testicular β-endorphin expression in Psammomys obesus

17β-estradiol effect on testicular β-endorphin expression in Psammomys obesus

Tissue-specific activity of the pro-opiomelanocortin gene promoter.

Proopiomelanocortin gene expression and DNA methylation: implications for Cushing's syndrome and beyond

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