Expression and processing of the [Pro(2),Met(13)]somatostatin-14 precursor in the intermediate lobe of the frog pituitary.

The biosynthesis of various hypothalamic neuropeptides has been previously reported in anterior pituitary cells but not in intermediate lobe cells. We have recently demonstrated the occurrence of two somatostatin isoforms in the frog brain, namely somatostatin-14 (SS1) and [Pro(2),Met(13)]somatostatin-14 (SS2). In the present study, we demonstrate that the gene encoding the SS2 precursor (PSS2) is actively expressed in the intermediate lobe of the frog pituitary. High concentrations of PSS2 mRNA have been detected by Northern blot analysis and in situ hybridization in the frog pars intermedia but not in the pars distalis or pars nervosa. The distribution of PSS1- and PSS2-derived peptides has been investigated by immunohistochemistry using two antisera directed against SS1 and the sequence 54-66 of PSS2 (PSS2(54-66)), respectively. The SS1 antiserum stained only a network of fibers in the neural lobe and a few nerve processes in the intermediate lobe. In contrast, the PSS2(54-66) antiserum produced intense labeling of melanotrope cells in the pars intermedia. Biochemical characterization of the immunoreactive materials present in pituitary extracts was performed by combining high-performance liquid chromatography analysis and RIA detection. The SS1 RIA revealed the existence of two major immunoreactive peaks that exhibited the same retention times as synthetic SS1 and SS2. The PSS2(54-66) RIA detected a single peak that likely corresponds to the N-flanking peptide of SS2 (PSS2(1-66)). The present study reveals that melanotrope cells of the frog pituitary selectively express the PSS2 gene and fully process PSS2 to generate the mature somatostatin variant SS2. Taken together, these data provide the first evidence that the gene encoding a hypophysiotropic neuropeptide is intensely expressed in the intermediate lobe of the pituitary.

[1]  B. Jenks,et al.  Coordinated expression of 7B2 and αMSH in the melanotrope cells of Xenopus laevis , 1991, Cell and Tissue Research.

[2]  G. Morel,et al.  Somatostatin-28- and somatostatin- 14-like immunoreactivities in the rat pituitary gland , 1988, Cell and Tissue Research.

[3]  H. Vaudry,et al.  Molecular Evolution of Somatostatin Genes , 2004 .

[4]  F. Vandesande,et al.  Somatostatin in the brain and the pituitary of some teleosts , 2004, Cell and Tissue Research.

[5]  Shigeyasu Tanaka,et al.  Immunocytochemical Localization of Prohormone Convertases PC1 and PC2 in the Mouse Thyroid Gland and Respiratory Tract , 2002, The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society.

[6]  H. Vaudry,et al.  Polygenic expression of somatostatin in the sturgeon Acipenser transmontanus: Molecular cloning and distribution of the mRNAs encoding two somatostatin precursors , 2002, The Journal of comparative neurology.

[7]  A. N. van den Pol,et al.  Immunohistochemical localization and biochemical characterization of hypocretin/orexin‐related peptides in the central nervous system of the frog Rana ridibunda , 2001, The Journal of comparative neurology.

[8]  B. Chronwall,et al.  Glial somatostatin-14 expression in the rat pituitary intermediate lobe: a possible neurotrophic function during development? , 2000, International Journal of Developmental Neuroscience.

[9]  H. Bennett,et al.  Processing of Rat Preprocortistatin in Mouse AtT‐20 Cells , 1999, Journal of neurochemistry.

[10]  Xin-wei Lin,et al.  Expression of three distinct somatostatin messenger ribonucleic acids (mRNAs) in goldfish brain: characterization of the complementary deoxyribonucleic acids, distribution and seasonal variation of the mRNAs, and action of a somatostatin-14 variant. , 1999, Endocrinology.

[11]  N. Seidah,et al.  Molecular cloning, characterization of cDNA, and distribution of mRNA encoding the frog prohormone convertase PC1 , 1999, The Journal of comparative neurology.

[12]  H. Vaudry,et al.  Frog chromogranin A messenger ribonucleic acid encodes three highly conserved peptides. Coordinate regulation of proopiomelanocortin and chromogranin A gene expression in the pars intermedia of the pituitary during background color adaptation. , 1999, Endocrinology.

[13]  H. Vaudry,et al.  Molecular cloning of the cDNAs and distribution of the mRNAs encoding two somatostatin precursors in the African lungfish Protopterus annectens. , 1999, The Journal of comparative neurology.

[14]  D. Vieau,et al.  Characterization of the cDNA encoding the prohormone convertase PC2 and localization of the mRNA in the brain of the frog Rana ridibunda. , 1998, Brain research. Molecular brain research.

[15]  B. Jenks,et al.  Dynamics of proopiomelanocortin and prohormone convertase 2 gene expression in Xenopus melanotrope cells during long-term background adaptation. , 1998, The Journal of endocrinology.

[16]  H. Vaudry,et al.  Pharmacological and Functional Characterization of Muscarinic Receptors in the Frog Pars Intermedia1 , 1998 .

[17]  Jeandel,et al.  Effects of the Two Somatostatin Variants Somatostatin‐14 and [Pro2, Met13]Somatostatin‐14 on Receptor Binding, Adenylyl Cyclase Activity and Growth Hormone Release from the Frog Pituitary , 1998, Journal of neuroendocrinology.

[18]  H. Vaudry,et al.  Immunocytochemical localization of somatostatin and autoradiographic distribution of somatostatin binding sites in the brain of the African lungfish, Protopterus annectens , 1997, The Journal of comparative neurology.

[19]  E. Roubos.  Background adaptation by Xenopus laevis: a model for studying neuronal information processing in the pituitary pars intermedia. , 1997, Comparative biochemistry and physiology. Part A, Physiology.

[20]  Y. Ueta,et al.  Pituitary adenylate cyclase-activating polypeptide potentiation of Ca2+ entry via protein kinase C and A pathways in melanotrophs of the pituitary pars intermedia of rats. , 1997, Endocrinology.

[21]  J. Sutcliffe,et al.  Cloning, mRNA expression, and chromosomal mapping of mouse and human preprocortistatin. , 1997, Genomics.

[22]  Shigeyasu Tanaka,et al.  Immunocytochemical localization of prohormone convertases PC1 and PC2 in the anuran pituitary gland: subcellular localization in corticotrope and melanotrope cells , 1997, Cell and Tissue Research.

[23]  H. Vaudry,et al.  Somatostatin- and urotensin II-related peptides: molecular diversity and evolutionary perspectives , 1997, Regulatory Peptides.

[24]  S. Hinuma,et al.  Identification and characterization of a novel human cortistatin-like peptide. , 1997, Biochemical and biophysical research communications.

[25]  P. Pagésy,et al.  [Paracrine regulation of anterior pituitary hormones by neuropeptides]. , 1997, Annales d'endocrinologie.

[26]  D. Vieau,et al.  Occurrence of two somatostatin variants in the frog brain: characterization of the cDNAs, distribution of the mRNAs, and receptor-binding affinities of the peptides. , 1996, Proceedings of the National Academy of Sciences of the United States of America.

[27]  P. Pagésy,et al.  Evidence of thyrotropin-releasing hormone (TRH) gene expression in rat anterior pituitaries and modulation by estrogens of TRH-like immunoreactivity and TRH-elongated peptide contents. , 1996, The Journal of endocrinology.

[28]  G. Martens,et al.  The Neuroendocrine Proteins Secretogranin II and III Are Regionally Conserved and Coordinately Expressed with Proopiomelanocortin in Xenopus Intermediate Pituitary , 1996, Journal of neurochemistry.

[29]  O. Prospero-Garcia,et al.  A cortical neuropeptide with neuronal depressant and sleep-modulating properties , 1996, Nature.

[30]  H. Vaudry,et al.  Evidence for the involvement of chromaffin cells in the stimulatory effect of tachykinins on corticosteroid secretion by the frog adrenal gland. , 1995, Endocrinology.

[31]  W. P. Hayes,et al.  Frog prohormone convertase PC2 mRNA has a mammalian‐like expression pattern in the central nervous system and is colocalized with a subset of thyrotropin‐releasing hormone‐expressing neurons , 1995, The Journal of comparative neurology.

[32]  N. Yanaihara,et al.  Localization of Pituitary Adenylate Cyclase‐Activating Polypeptide (PACAP) in the Hypothalamus‐Pituitary System in Rats: Light and Electron Microscopic Immunocytochemical Studies , 1994, Journal of neuroendocrinology.

[33]  T. Bruhn,et al.  Thyrotropin-releasing hormone (TRH) gene expression in the anterior pituitary. I. Presence of pro-TRH messenger ribonucleic acid and pro-TRH-derived peptide in a subpopulation of somatotrophs. , 1994, Endocrinology.

[34]  H. Vaudry,et al.  Ontogeny of diazepam-binding inhibitor-related peptides (endozepines) in the rat brain , 1993, Neuroscience.

[35]  H. Vaudry,et al.  Isolation of [Pro2,Met13]somatostatin-14 and somatostatin-14 from the frog brain reveals the existence of a somatostatin gene family in a tetrapod. , 1992, Biochemical and biophysical research communications.

[36]  S. Bloom,et al.  Expression of messenger ribonucleic acids encoding neuropeptide-Y, substance-P, and vasoactive intestinal polypeptide in human pituitary. , 1992, The Journal of clinical endocrinology and metabolism.

[37]  G J Martens,et al.  Structure and expression of Xenopus prohormone convertase PC2 , 1992, FEBS letters.

[38]  P. Pagésy,et al.  Evidence of gonadotropin-releasing hormone mRNA in the rat anterior pituitary. , 1992, Molecular endocrinology.

[39]  P. Pagésy,et al.  Immunoreactive thyroliberin (TRH) precursor forms in human hypothalamus and anterior pituitary tissues , 1992, FEBS letters.

[40]  M. Feuilloley,et al.  Distribution and characterization of immunoreactive growth hormone (GH) in the pituitary of the frog Rana ridibunda using an antiserum against purified bullfrog GH. , 1991, General and comparative endocrinology.

[41]  B. Jenks,et al.  Coordinated expression of 7B2 and alpha MSH in the melanotrope cells of Xenopus laevis. An immunocytochemical and in situ hybridization study. , 1991, Cell and tissue research.

[42]  H. Vaudry,et al.  Characterization of melanotropin-release-inhibiting factor (melanostatin) from frog brain: homology with human neuropeptide Y. , 1991, Proceedings of the National Academy of Sciences of the United States of America.

[43]  D. Vieau,et al.  CORTICOTROPHIN‐LIKE INTERMEDIARY LOBE PEPTIDE AS A MARKER OF ALTERNATE PRO‐OPIOMELANOCORTIN PROCESSING IN ACTH‐PRODUCING NON‐PITUITARY TUMOURS , 1989, Clinical endocrinology.

[44]  J. Martial,et al.  Evidence of pre-prosomatostatin mRNA in human normal and tumoral anterior pituitary gland. , 1989, Molecular endocrinology.

[45]  P. Leroux,et al.  Distribution of somatostatin receptors in the brain of the frog Rana ridibunda: Correlation with the localization of somatostatin‐containing neurons , 1989, The Journal of comparative neurology.

[46]  J. D. Neill,et al.  Autocrine control of prolactin secretion by vasoactive intestinal peptide. , 1988, Endocrinology.

[47]  G. Childs,et al.  Persistence of immunoreactive TRH and GnRH in long-term primary anterior pituitary cultures , 1987, Peptides.

[48]  P. Chomczyński,et al.  Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction. , 1987, Analytical biochemistry.

[49]  B. Jenks,et al.  Physiologically-induced changes in proopiomelanocortin mRNA levels in the pituitary gland of the amphibian Xenopus laevis. , 1987, Biochemical and biophysical research communications.

[50]  T. Garthwaite,et al.  Vasoactive intestinal polypeptide is synthesized in anterior pituitary tissue. , 1986, Endocrinology.

[51]  R. Nishioka,et al.  Somatostatin-like immunoreactivity in the pituitary and brain of three teleost fish species: somatostatin as a potential regulator of prolactin cell function. , 1985, General and comparative endocrinology.

[52]  P. Leroux,et al.  In vitro study of frog (Rana ridibunda Pallas) neurointermediate lobe secretion by use of a simplified perifusion system. III. Effect of neuropeptides on alpha-MSH secretion. , 1983, General and comparative endocrinology.

[53]  P. Mandel,et al.  Presence of Somatostatin, Enkephalins, and Substance P‐Like Peptides in Cultured Neurons from Embryonic Chick Cerebral Hemispheres , 1983, Journal of neurochemistry.

[54]  P. Leroux,et al.  Catecholaminergic Control of α-Melanocyte-Stimulating Hormone (αMSH) Release by Frog Neurointermediate Lobe in Vitro: Evidence for Direct Stimulation of αMSH Release by Thyrotropin-Releasing Hormone* , 1983 .

[55]  H. Vaudry,et al.  Biological and radioimmunological evidence for melanocyte stimulating hormones (MSH) of extrapituitary origin in the rat brain. , 1978, Neuroendocrinology.