Analysis of POMC Gene Expression by Transcription Assay and In Situ Hybridization Histochemistry

Roberts, Jodie; Eberwine, Jim; Gee, Connie E.

doi:10.1101/sqb.1983.048.01.042

Cited by 11 publications

(7 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It has been shown that factors which influence the secretory process in POMC-producing cells can also affect the rate of biosynthesis of the prohormone. For example, dexamethasone, a synthetic glucocorticoid known to inhibit the release of POMC-related peptides from the anterior pituitary [1,25], also suppresses transcription of the POMC gene [3,27]. More relevant to the present investigation is the observation that chronic treatment of rats with dopamine agonists decreases the levels of POMC mRNA in the intermediate lobe of the rat [5] while treatment with antagonists increases mRNA levels [5,16].…”

Section: Discussionmentioning

confidence: 98%

Regulation of biosynthesis and release of pars intermedia peptides in Rana ridibunda: Dopamine affects both acetylation and release of α-MSH

et al. 1985

View full text Add to dashboard Cite

Dopamine is likely an important physiological melanotropin release-inhibiting factor in amphibians. This study concerns the effects of dopamine on the biosynthesis and release of peptides from the pars intermedia of the frog Rana ridibunda. Our results show that this secretagogue has no immediate effects on either the rate of biosynthesis of pro-opiomelanocortin nor on the direction of processing of this prohormone. Pulse-chase experiments revealed that dopamine inhibited the release of all newly synthesized POMC-related peptides in a dose-dependent manner. For each dopamine concentration tested, the degree of inhibition exerted on the release of the various newly synthesized peptides by a given concentration of secretagogue was approximately the same, with the exception of that found for the alpha-MSH related peptides. Analysis of the release of these melanotropins was complex because dopamine not only inhibited their release but also, either directly or indirectly, inhibited the acetylation reaction which converts des-N alpha-acetyl alpha-MSH to alpha-MSH. Dopamine was shown to be less potent in inhibiting the release of des-N alpha-acetyl alpha-MSH than inhibiting release of the acetylated form of the peptide. In amphibians a preferential release of the less-bioactive non-acetylated form of MSH under inhibitory conditions induced by dopamine may be of physiological importance.

show abstract

Section: Discussionmentioning

confidence: 98%

Regulation of biosynthesis and release of pars intermedia peptides in Rana ridibunda: Dopamine affects both acetylation and release of α-MSH

et al. 1985

View full text Add to dashboard Cite

show abstract

“…This study therefore does not address molecular mechanisms underlying these changes. However, genes coding for peptides and enzymes have been shown to be regulated by changes in gene transcription (Roberts et al, 1983;Comb et a/. , 1986;Lewis et al, 1987), increased mRNA degradation (Casey ef al., 1988), changes in mRNA stability (Salton et al, 1988) or combinations of these mechanisms (Dong, 1989).…”

Section: Discussionmentioning

confidence: 99%

Calcitonin Gene‐related Peptide (CGRP)‐like Immunoreactivity and CGRP mRNA in Rat Spinal Cord Motoneurons after Different Types of Lesions

Piehl

Arvidsson

Johnson

et al. 1991

Eur J of Neuroscience

View full text Add to dashboard Cite

By use of the indirect immunofluorescence (IF) technique, radioimmunoassay (RIA) and in situ hybridization (ISH) histochemistry, the staining pattern, content and expression of calcitonin gene-related peptide (CGRP) in lumbar motoneurons of normal rats and rats subjected to sciatic nerve transection (SNT), ventral root transection (VRT), low thoracic spinal cord transection (SCT) alone or in combination with a subsequent SNT, as well as rats subjected to chemical lesioning of 5-hydroxytryptamine (5-HT) neurons by 5,7-dihydroxytryptamine (5,7-DHT), were studied. We here confirm that a large number of the lumbar motoneurons normally contain CGRP-like immunoreactivity (LI) and CGRP mRNA. SNT induced a transient increase in CGRP-LI, with a peak at days 2 - 5 after lesion, and normalized levels again after approximately 2 - 3 weeks. Comparable results were obtained with IF and RIA. This increase is probably a consequence of increased CGRP synthesis, since a parallel up-regulation of CGRP mRNA levels was seen. A normalization of CGRP mRNA did not occur during the period studied, despite an apparent normalization of peptide levels after 2 weeks, and this may in turn be due to an increased turnover and/or release of CGRP. The up-regulation of CGRP is probably caused by the axon injury itself, since a similar cellular reaction with respect to CGRP was observed in motoneurons subjected to VRT. However, SNT, which also lesions dorsal root afferents and causes a decline in CGRP-LI in the dorsal horn, induced an increase in CGRP-LI in motoneurons on the contralateral side also. Thus, it may be that severance of dorsal root afferents and/or changes in reflex activity may also influence the production of CGRP in motoneurons. SCT, which severs all descending synaptic input to the motor nucleus and causes a paralysis of muscles innervated by motoneurons below the lesion, resulted in a marked decline in both content of CGRP-LI (IF and RIA) and expression of CGRP mRNA. However, treatment with 5,7-DHT, which lesions 5-HT neurons, including those giving rise to the bulbospinal serotoninergic pathway, did not cause any dramatic changes in motor behaviour but induced an increase in both motoneuron content of CGRP-LI and expression of CGRP mRNA. In rats first subjected to SCT, which depresses CGRP, followed 2 weeks later by SNT, we found a marked increase in both content of CGRP-LI (IF and RIA) and expression of mRNA coding for CGRP. In summary our results show that the cellular production of the CGRP peptide, normally expressed in motoneurons, is influenced in a complex way by motoneuron injury as well as changes in the afferent input. There also appear to be important differences in the expression of CGRP in small (gamma) and large (alpha) motoneurons as well as between motoneurons of different nuclei, in normal as well as axotomized rats.

show abstract

“…233) and, in turn, cAMP increases POMC mRNA accumulation, several groups have investigated whether or not delayed feedback has an effect on cAMP metabolism. The results are conflicting: two studies reported an inhibition by dexamethasone of CRF-41-induced cAMP accumulation in anterior pituitary cell cultures (41, 234), while two others found no effect of the steroid (230,235).…”

Section: And Ref 66)mentioning

confidence: 99%

“…Given the neuroanatomical findings described above, the most plausible interpretation of these results is that preterminal magnocellular axons originating from the supraoptic nucleus release vasopressin in the ME. The neurovascular organization of the ME is such that peptides released from magnocellular fibers, perhaps at large swellings called Herring-bodies, could gain access to the pituitary portal circulation by simple diffusion (216)(217)(218)(219)(220)(221)(222)(223)(224)(225)(226)(227)(228)(229)(230)(231)(232)(233)(234)(235).…”

Section: Investigation Of the Corelease Of Crf-41 And Vasopressin In mentioning

confidence: 99%

Hypothalamic Control of Adrenocorticotropin Secretion: Advances since the Discovery of 41-Residue Corticotropin-Releasing Factor

1986

View full text Add to dashboard Cite

Analysis of POMC Gene Expression by Transcription Assay and In Situ Hybridization Histochemistry

Cited by 11 publications

References 0 publications

Regulation of biosynthesis and release of pars intermedia peptides in Rana ridibunda: Dopamine affects both acetylation and release of α-MSH

Regulation of biosynthesis and release of pars intermedia peptides in Rana ridibunda: Dopamine affects both acetylation and release of α-MSH

Calcitonin Gene‐related Peptide (CGRP)‐like Immunoreactivity and CGRP mRNA in Rat Spinal Cord Motoneurons after Different Types of Lesions

Hypothalamic Control of Adrenocorticotropin Secretion: Advances since the Discovery of 41-Residue Corticotropin-Releasing Factor

Contact Info

Product

Resources

About