Advances in Experimental Medicine and Biology, 2002
... calcium (Ochoa et al 1989), and peptides including substance P (Livett and Marley 1993) and c... more ... calcium (Ochoa et al 1989), and peptides including substance P (Livett and Marley 1993) and calcitonin gene-related peptide (Ochoa et al ... Fishbein, VA, Coy, DH, Hocart, SJ, Jiang, NY, Mrozinski, JE, Jr., Mantey, SA, and Jensen, RT 1994, A chimeric VIP-PACAP analogue but ...
Background-Endothelial dysfunction predisposes to vascular injury in association with hypertensio... more Background-Endothelial dysfunction predisposes to vascular injury in association with hypertension. Endothelin (ET-1) is a potent vasoactive peptide that is synthesized and released by the vascular endothelium and is a marker of endothelial function. Chromogranin A (CHGA) regulates the storage and release of catecholamines and may have direct actions on the microvasculature. CHGA, a candidate gene for intermediate phenotypes that contribute to hypertension, shows a pattern of single nucleotide polymorphism variations that alter the expression and function of this gene both in vivo and in vitro. Methods and Results-In a study of twins (nϭ238 pairs), plasma ET-1 was 58Ϯ5% (PϽ0.0001) heritable. Plasma ET-1 was both correlated and associated with chromogranin fragment levels, and the 2 were influenced by shared genetic determination (pleiotropy [ G ]; for the CHGA precursor, G ϭ0.318Ϯ0.105; Pϭ0.0032). We therefore hypothesized that variation in the CHGA gene may influence ET-1 secretion. Carriers of the CHGA promoter Ϫ988G, Ϫ462A, and Ϫ89A minor alleles showed significantly higher mean plasma ET-1 than their major allele homozygote counterparts (Pϭ0.02, Pϭ0.006, Pϭ0.03, respectively). Analysis of a linkage disequilibrium block that spans these 3 single nucleotide polymorphisms showed a significant association between the GATACA haplotype and plasma ET-1 (Pϭ0.0075). In cultured human umbilical vein endothelial cells, CHGA caused dose-dependent secretion of ET-1 over a brief (Ͻ1 hour) time course at relatively low concentrations of CHGA (10 to 100 nmol/L) with a threshold concentration (10 nmol/L) in the range found circulating in humans in vivo. Conclusions-These results suggest that common, heritable variation in expression of the human CHGA gene influences endothelial ET-1 secretion in vivo, explained by a CHGA stimulus/ET-1 secretion coupling in endothelial cells in vitro. The findings document a previously unsuspected interaction between the sympathochromaffin system and the endothelium and suggest novel genetic and cell biological approaches to the prediction, diagnosis, and mechanism of endothelial dysfunction in human disease. (Circulation. 2007;115:2282-2291.)
Pituitary adenylyl cyclase-activating polypeptide (PACAP) is a potent endogenous secretagogue for... more Pituitary adenylyl cyclase-activating polypeptide (PACAP) is a potent endogenous secretagogue for chromaffin cells. We previously reported that PACAP coupled to the PAC1 receptor to evoke dihydropyridine-sensitive early (15 to 20 minutes) catecholamine secretion and cAMP response element binding protein-mediated trans-activation of the secretory protein chromogranin A promoter in PC12 pheochromocytoma cells. In this report, we studied whether the secretory and transcriptional responses elicited by PACAP were subject to desensitization. We found that PACAP evoked distinct immediate (initial, 0 to 20 minutes) and long-lasting (20 to 180 minutes) effects on catecholamine secretion. Initial secretory and chromogranin A trans-activation responses induced by PACAP were desensitized in a dose-dependent fashion after preexposure of cells to PACAP, and the IC 50 doses of PACAP for desensitization were Ϸ18to Ϸ32-fold lower than the EC 50 activating doses for secretion or transcription. Desensitization of the initial secretion response was associated with decreased Ca 2ϩ influx through L-type voltage-operated Ca 2ϩ channels. Acute exposure to PACAP also triggered long-lasting (up to 3 hours), extracellular Ca 2ϩ -dependent, pertussis toxin-insensitive catecholamine secretion; indeed, even after short-term (20 minutes) exposure to PACAP and removal of the secretagogue, PC12 cells continued to secrete norepinephrine up to 76.9Ϯ0.22% of cellular norepinephrine content after 3 hours. A phospholipase C- inhibitor (U-73122) blocked this extended secretory response, which was dependent on low-magnitude Ca 2ϩ influx resistant to several L-, N-, P/Q-, or T-type Ca 2ϩ channel antagonists, but sensitive to Zn 2ϩ , Ni 2ϩ , Cd 2ϩ , or to the store-operated Ca 2ϩ channel blocker SKF96365. A less than additive effect of the sarcoendoplasmic reticulum Ca 2ϩ -ATPase inhibitor thapsigargin plus PACAP on this sustained secretion also supported a contribution of store-operated Ca 2ϩ entry to the sustained secretory response. We propose that PACAP-evoked secretion and transcription are subject to homologous desensitization in PC12 cells; however, PACAP also induces long-lasting secretion, even under dose and time circumstances in which acute, dihydropyridine-sensitive secretion has been desensitized. Although initial secretion is mediated by an L-type voltage-operated Ca 2ϩ channel, extended secretion may involve a store-operated Ca 2ϩ channel that is activated through a G q/11 /phospholipase C-/phosphoinositide signaling pathway. (Hypertension. 1999;34:1152-1162.)
Activation of protein kinase C (PKC) stimulates nicotine-induced catecholamine secretion. PKC dow... more Activation of protein kinase C (PKC) stimulates nicotine-induced catecholamine secretion. PKC down-regulation by prolonged pretreatment with phorbol 12-myristate 13-acetate diminished nicotine-induced catecholamine secretion only slightly (approximately 16%), suggesting substantial PKC independence of nicotinic receptor activation. However, we found that bisindolylmaleimide compounds (which are also putative PKC chemical inhibitors) dramatically inhibited nicotine-induced catecholamine secretion (IC(50) values of approximately 24-37 nM). This inhibition was specific for the nicotinic cholinergic receptor. Catecholamine secretion induced by other nicotinic agonists (such as epibatidine, anatoxin, or cytisine) was also powerfully antagonized by bisindolylmaleimide II (IC(50) values of approximately 60-90 nM). Even high-dose nicotinic agonists failed to overcome the inhibition by bisindolylmaleimide II, suggesting noncompetitive nicotinic antagonism by this class of compounds. Nicotini...
Dopamine beta-hydroxylase (DBH) is the biosynthetic enzyme catalyzing formation of norepinephrine... more Dopamine beta-hydroxylase (DBH) is the biosynthetic enzyme catalyzing formation of norepinephrine. Changes in DBH expression or activity have been implicated in the pathogenesis of cardiovascular and neuropsychiatric disorders. Genetic determination of DBH enzymatic activity and its secretion are only incompletely understood. We began with a genome-wide association search for loci contributing to DBH activity in human plasma. Initially, in a population sample of European ancestry, we identified the proximal DBH promoter as a region harboring three common trait-determining variants (top hit rs1611115, P = 7.2 × 10(-51)). We confirmed their effects on transcription and showed that the three variants each acted additively on gene expression. Results were replicated in a population sample of Native American descent (top hit rs1611115, P = 4.1 × 10(-15)). Jointly, DBH variants accounted for 57% of DBH trait variation. We further identified a genome-wide significant SNP at the LOC338797 l...
The molecular basis of neuroendocrine-specific expression of chromogranin B gene (Chgb) has remai... more The molecular basis of neuroendocrine-specific expression of chromogranin B gene (Chgb) has remained elusive. Utilizing wild-type and mutant Chgb promoter/luciferase reporter constructs, this study established a crucial role for the cAMP response element (CRE) box at )102/)95 bp in endocrine [rat pheochromocytoma (chromaffin) cell line (PC12) and rat pituitary somatotrope cell line (GC)] and neuronal [rat dorsal root ganglion/mouse neuroblastoma hybrid cell line (F-11), cortical and hippocampal primary neurons] cells. Additionally, G/C-rich domains at )134/)127, )125/)117 and )115/)110 bp played especially important roles for endocrine-specific expression of the Chgb gene. Co-transfection of expression plasmids for CREB, activator protein-2 (transcription factor) (AP-2), early growth response protein (transcription factor) (Egr-1) or specificity protein 1 (transcription factor) (Sp1) with the Chgb promoter constructs trans-activated expression of the Chgb gene. Nuclear extracts from either PC12 or F-11 cells formed specific complexes with the Chgb ()110/)87 bp) (CRE) oligonucleotide, which were either supershifted or disrupted by anti-CREB antibodies. In addition PC12 nuclear extracts also formed a specific complex with a Chgb ()140/)104-bp) oligonucleotide containing three G/C-rich regions, which was dose-dependently disrupted by anti-AP-2, anti-Egr-1 or anti-Sp1 antibodies; indeed, any one of these three antibodies completely abolished the complex, suggesting that all three factors bind the region simultaneously, at least in vitro. Chromatin immunoprecipitation assays documented the binding of the transcription factors CREB, AP-2, Egr-1 and Sp1 to the chromosomal Chgb gene promoter in vivo in PC12 cells within the context of chromatin. We conclude that the neuroendocrine-specific expression of Chgb is mediated by the CRE and G/C boxes in cis and the transcription factors CREB, AP-2, Egr-1 and Sp1 in trans.
Chromogranins or secretogranins (granins), present in secretory granules of virtually all neuroen... more Chromogranins or secretogranins (granins), present in secretory granules of virtually all neuroendocrine cells and neurones, are structurally related proteins encoded by different genetic loci: chromogranins A and B, and secretogranins II through VI. Compelling evidence supports both intracellular and extracellular functions for this protein family. Within the cells of origin, a granulogenic or sorting role in the regulated pathway of hormone or neurotransmitter secretion has been documented, especially for chromogranin A (CHGA). Granins also function as pro-hormones, giving rise by proteolytic processing to an array of peptide fragments for which diverse autocrine, paracrine, and endocrine activities have been demonstrated. CHGA measurements yield insight into the pathogenesis of such human diseases as essential hypertension, in which deficiency of the catecholamine release-inhibitory CHGA fragment catestatin may trigger sympathoadrenal overactivity as an aetiologic culprit in the syndrome. The CHGA dysglycaemic fragment pancreastatin is functional in humans in vivo, affecting both carbohydrate (glucose) and lipid (fatty acid) metabolism. Pancreastatin is cleaved from CHGA in hormone storage granules in vivo, and its plasma concentration varies in human disease. The pancreastatin region of CHGA gives rise to three naturally occurring human variants, one of which (Gly297Ser) occurs in the functionally important carboxy-terminus of the peptide, and substantially increases the peptide's potency to inhibit cellular glucose uptake. These observations establish a role for pancreastatin in human intermediary metabolism and disease, and suggest that qualitative hereditary alterations in pancreastatin's primary structure may give rise to interindividual differences in glucose disposition.
Previous modeling (PDB 1cfk) of the catecholamine release-inhibitory &amp... more Previous modeling (PDB 1cfk) of the catecholamine release-inhibitory "catestatin" region of chromogranin A (CgA) suggested a beta-strand/loop/beta-strand active conformation, displaying an electropositive Arg-rich loop (R(351)AR(353)GYGFR(358)). To explore this possibility, we studied NMR structures of linear and cyclic synthetic catestatin, bovine (bCgA(344-364)) or human (hCgA(352-372)). By 2-D (1)H-NMR, the structure of linear catestatin (hCgA(352-372)) exhibited the NOE pattern of a coiled loop (PDB 1lv4). We then constrained the structure, cyclizing the putative Arg-rich loop connecting the beta-strands: cyclic bCgA(350-362) ([C(0)]F(350)RARGYGFRGPGL(362)[C(+14)]). Favored conformations of cyclic bCgA(350-362) were determined by (1)H-NMR and (13)C-NMR spectroscopy. Cyclic bCgA(350-362) conformers (PDB 1n2y) adopted a…
Background: Elevated sympathetic activity is associated with kidney dysfunction. Here we used twi... more Background: Elevated sympathetic activity is associated with kidney dysfunction. Here we used twin pairs to probe heritability of GFR and its genetic covariance with other traits.
Journal of the American College of Cardiology, 2014
This study coupled 2 strategiesdtrait extremes and genome-wide poolingdto discover a novel blood ... more This study coupled 2 strategiesdtrait extremes and genome-wide poolingdto discover a novel blood pressure (BP) locus that encodes a previously uncharacterized thiamine transporter.
C-reactive protein (CRP) both reflects and participates in inflammation, and its circulating conc... more C-reactive protein (CRP) both reflects and participates in inflammation, and its circulating concentration marks cardiovascular risk. Here we sought to understand the role of heredity in determining CRP secretion. CRP, as well as multiple facets of the metabolic syndrome, were measured in a series of 229 twins, both monozygotic (MZ) and dizygotic (DZ), to estimate trait heritability (h2). Single nucleotide polymorphism (SNP) genotyping was done at adrenergic pathway loci. Haplotypes were inferred from genotypes by likelihood methods. Association of CRP with hypertension and the metabolic syndrome was studied in a larger series of 732 individuals, including 79 with hypertension. MZ and DZ twin variance components indicated substantial h2 for CRP, at approximately 56 +/- 7% (P < 0.001). CRP was significantly associated (P < 0.05) with multiple features of the metabolic syndrome in twins, including body mass index (BMI), blood pressure (BP), leptin and lipids. In established hypertension, elevated CRP was associated with increased BP, BMI, insulin, HOMA (index of insulin resistance), leptin, triglycerides and norepinephrine. Twin correlations indicated pleiotropy (shared genetic determination) for CRP with BMI (P = 0.0002), leptin (P < 0.001), triglycerides (P = 0.002) and systolic blood pressure (SBP) (P = 0.042). Approximately 9800 genotypes (43 genetic variants at 17 loci) were scored within catecholaminergic pathways: biosynthetic, receptor and signal transduction. Plasma CRP concentration in twins was predicted by polymorphisms at three loci in physiological series within the catecholamine biosynthetic/beta-adrenergic pathway: TH (tyrosine hydroxylase), ADRB1 (beta1-adrenergic receptor) and ADRB2 (beta2-adrenergic receptor). In the TH promoter, common allelic variation accounted for up to approximately 6.6% of CRP inter-individual variance. At ADRB1, variation at Gly389Arg predicted approximately 2.8% of CRP, while ADRB2 promoter variants T-47C and T-20C also contributed. Particular haplotypes and diplotypes at TH and ADRB1 also predicted CRP, though typically no better than single SNPs alone. Epistasis (gene-by-gene interaction) was demonstrated for particular combinations of TH and ADRB2 alleles, consistent with their actions in a pathway in series. In an illustration of pleiotropy, not only CRP but also plasma triglycerides were predicted by…
The mRNA levels of secretogranin II, chromogranin B, and VGF were compared in brains of control a... more The mRNA levels of secretogranin II, chromogranin B, and VGF were compared in brains of control and AF64A-treated rats. This toxin induces specific lesions of the septohippocampal cholinergic pathway. As a consequence of this treatment, the chromoaranin B message was elevated in the dentate gyrus grarlule cells of the hippocampus. In the paraventricular nucleus of the hypothalamus, a concomitant elevation of the messages of secretogranin II and corticotropin-releasing factor occurred in the parvocellular neurons, and an increase of those of secretogranin II and VGF occurred in a subgroup of magnocellular neurons. Further increases for secretogranin II were seen in the amygdaloid nuclei and the reticular thalamic nuclei and increases for chromogranin B in the temporal cortex, substantia nigra compacta, and ventral tegmental area. These results indicate that the toxin-induced lesion of the cholinergic pathway innervating the hippocampus apparently leads to the stimulation of several defined groups of neurons that react with an increase in the mRNA levels of their secretory peptides. We suggest that changes in mRNA expression of these peptides are useful parameters for defining neurons under chronic stimulation. Key Words: Secretory peptides-Large dense core vesicles -Corticotropinreleasing factor -Septohippocampal cholinergic system-Hippocampus-AF64A.
BACKGROUNDThe Seventh Joint National Committee on Prevention, Detection, Evaluation, and Treatmen... more BACKGROUNDThe Seventh Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure in 2003 created a prehypertension category for persons with blood pressures ranging from systolic blood pressure (SBP) of 120–139 mm Hg or diastolic blood pressure (DBP) from 80 to 89 mm Hg, due to increased risk of cardiovascular disease.METHODSOur study utilized the University of California-San Diego (UCSD) Twin Hypertension Cohort. We measured comprehensive plasma cholesterol levels and metabolic (glucose, insulin, leptin) and inflammatory markers (interleukin-6 (IL-6), C-reactive protein (CRP), free fatty acids) to determine the differences between normotensive and prehypertensive subjects. Additionally, we determined whether angiotensin II receptor type-1 (AGTR1) polymorphisms, previously associated with hypertension, could predict prehypertension.RESULTSA total of 455 white subjects were included in the study (mean age 37.1 years). Prehypertensive subjects were older with greater body mass index (BMI) than the normotensives, and after adjusting for sex and age, had greater plasma glucose, insulin, and IL-6. The common AGTR1 A1166C (rs5186) polymorphism in the 3′-UTR region, particularly the presence of the 1166C allele, which fails to downregulate gene expression, predicted greater likelihood of being in the prehypertension group and higher SBP. A lesser-studied polymorphism in intron-2 of AGTR1 (A/G; rs2276736) was associated with plasma high-density lipoprotein (HDL) and apolipoprotein A-1. In a subgroup analysis of nonobese subjects (N = 405), similar associations were noted.CONCLUSIONPrehypertensive subjects already exhibit early pathophysiologic changes putting them at risk of future cardiovascular disease, and AGTR1 may also contribute to this increased risk. Further investigation is needed to confirm these findings and the precise molecular mechanisms of action.
In 1997, we identified a novel peptide, catestatin (CST: bovine chromogranin A [CHGA] 344-364 : R... more In 1997, we identified a novel peptide, catestatin (CST: bovine chromogranin A [CHGA] 344-364 : RSMRLSFRARGYGFRGPGLQL; human CHGA 352-372 : SSMKLSFRARGYGFRGPGPQL), which is a potent inhibitor of nicotinic cholinergic-stimulated catecholamine secretion. CST shows characteristic inhibitory effects on nicotinic cationic (Na + , Ca 2+ ) signal transduction, which are specific to the neuronal nicotinic receptor. Utilizing systematic polymorphism discovery at the human CHGA locus we discovered three human variants of CST: G 364 S, P 370 L, and R 374 Q that showed differential potencies towards inhibition of catecholamine secretion. In humans, CHGA is elevated and its processing to CST is diminished in hypertension. Diminished CST is observed not only in hypertensive individuals but also early-normotensive offspring of patients with hypertension, suggesting that an early deficiency of CST might play a pathogenic role in the subsequent development of the disease. Consistent with human findings, prevention of endogenous CST expression by targeted ablation (knockout) of the mouse Chga locus (Chga-KO) resulted in severe hypertension that can be "rescued" specifically by replacement of the CST peptide. CST acts directly on the heart to inhibit the inotropic and lusitropic properties of the rodent heart and also acts as a potent vasodilator in rat and human. While the G 364 S CST variant caused profound changes in human autonomic activity and seemed to reduce risk of developing hypertension, CST replacement rescued Chga-KO mice from dampened baroreflex sensitivity. In addition, CST has been shown to induce chemotaxis and acts as an antimicrobial as well as an antimalarial peptide. The present review summarizes these multiple actions of CST.
Pituitary adenylyl cyclase activating polypeptide (PACAP) and vasoactive intestinal polypeptide (... more Pituitary adenylyl cyclase activating polypeptide (PACAP) and vasoactive intestinal polypeptide (VIP) augment the biosynthesis of tyrosine hydroxylase (TH). We tested whether secretin belonging to the glucagon/ PACAP/VIP superfamily would increase transcription of the tyrosine hydroxylase (Th) gene and modulate catecholamine secretion. Secretin activated transcription of the endogenous Th gene and its transfected promoter (EC 50 ∼4.6 nM) in pheochromocytoma (PC12) cells. This was abolished by pre-treatment with a secretin receptor (SCTR) antagonist and by inhibition of protein kinase A (PKA), mitogen-activated protein kinase, or CREB (cAMP response element-binding protein). In agreement, secretin increased PKA activity and induced phosphorylation of CREB and binding to Th CRE, suggesting secretin signaling to transcription via a PKA-CREB pathway. Secretin stimulated catecholamine secretion (EC 50 ∼3.5 μM) from PC12 cells, but this was inhibited by pre-treatment with VIP-preferring receptor (VPAC1)/PACAP-preferring receptor (PAC1) antagonists. Secretin-evoked secretion occurred without extracellular Ca 2+ and was abolished by intracellular Ca 2+ chelation. Secretin augmented phospholipase C (PLC) activity and increased inositol-1,4,5-triphosphate (IP 3 ) levels in PC12 cells; PLC-β inhibition blocked secretin-induced catecholamine secretion, indicating the participation of intracellular Ca 2+ from a phospholipase pathway in secretion. Like PACAP, secretin evoked long-lasting catecholamine secretion, even after only a transient exposure. Thus, transcription is triggered by nanomolar concentrations of the peptide through SCTR, with signaling along the cAMP-PKA and extracellular-signal-regulated kinase 1/2 pathways and through CREB. By contrast, secretion is triggered only by micromolar concentrations of peptide through PAC1/VPAC receptors and by utilizing a PLC/intracellular Ca 2+ pathway.
Hypertension and its related increase in cardiovascular morbidity in postmenopausal women is a ma... more Hypertension and its related increase in cardiovascular morbidity in postmenopausal women is a major public health problem. The hypotensive property of urinary kallikrein has been described since 1909. Despite the controversy surrounding the effects of hormone replacement therapy on blood pressure regulation, its mechanisms remain incompletely understood, and no evidence has yet been provided for its effects on renal kallikrein excretion in postmenopausal women.
Obesity is a heritable trait that contributes to hypertension and subsequent cardiorenal disease ... more Obesity is a heritable trait that contributes to hypertension and subsequent cardiorenal disease risk; thus, the investigation of genetic variation that predisposes individuals to obesity is an important goal. Circulating peptide YY (PYY) is known for its appetite and energy expenditure-regulating properties; linkage and association studies have suggested that PYY genetic variation contributes to susceptibility for obesity, rendering PYY an attractive candidate for study of disease risk. To explore whether common genetic variation at the human PYY locus influences plasma PYY or metabolic traits, we systematically resequenced the gene for polymorphism discovery and then genotyped common single-nucleotide polymorphisms across the locus in an extensively phenotyped twin sample to determine associations. Finally, we experimentally validated the marker-on-trait associations using PYY 3'-untranslated region (UTR)/reporter and promoter/reporter analyses in neuroendocrine cells. Four common genetic variants were discovered across the locus, and three were typed in phenotyped twins. Plasma PYY was highly heritable (P < 0.0001), and genetic pleiotropy was noted between plasma PYY and body mass index (BMI) (P = 0.03). A PYY haplotype extending from the proximal promoter (A-23G, rs2070592) to the 3'-UTR (C+1134A, rs162431) predicted not only plasma PYY (P = 0.009) but also other metabolic syndrome traits. Functional studies with transfected luciferase reporters confirmed regulatory roles in altering gene expression for both 3'-UTR C+1134A (P < 0.001) and promoter A-23G (P = 0.0016). Functional genetic variation at the PYY locus influences multiple heritable metabolic syndrome traits, likely conferring susceptibility to obesity and subsequent cardiorenal disease.
Secretoneurin is a peptide of 33 amino acids generated in brain by proteolytic processing of secr... more Secretoneurin is a peptide of 33 amino acids generated in brain by proteolytic processing of secretogranin 11. The distribution of this newly characterized peptide was investigated by means of immunocytochemistry and in situ hybridization in the spinal cord and lower brainstem of the rat. The staining pattern of secretoneurin immunoreactivity (IR) was compared to that of substance P (SP) and calcitonin gene-related peptide (CGRP) in adjacent sections. A high density of secretoneurin-IR fibers and terminals was found in lamina I and outer lamina I1 of the caudal trigeminal nucleus and of the spinal cord a t all levels, around the central canal, and in the sympathetic and parasympathetic areas of the lateral cell columns. The ventral horn displayed a low to moderate density of secretoneurin-IR. The highest number of secretogranin I1 mRNA-containing cells was found in lamina I1 of the dorsal horn and in neurons of the dorsal root ganglia. In the white matter, secretoneurin-IR was most prominent in the dorsolateral part of the lateral funiculus and in the tract of Lissauer. The distributions of secretoneurin-IR and SP-IR were strikingly similar. CGRP-IR and secretoneurin-IR overlapped in the outer laminae of the dorsal horn, in the lateral cell column, and probably in some motoneurons. This study establishes that, like SP and CGRP, secretoneurin is a peptide highly concentrated in the terminal field of primary afferents and in sympathetic and parasympathetic areas. Thus secretoneurin might be involved in the modulation of afferent transmission.
Advances in Experimental Medicine and Biology, 2002
... calcium (Ochoa et al 1989), and peptides including substance P (Livett and Marley 1993) and c... more ... calcium (Ochoa et al 1989), and peptides including substance P (Livett and Marley 1993) and calcitonin gene-related peptide (Ochoa et al ... Fishbein, VA, Coy, DH, Hocart, SJ, Jiang, NY, Mrozinski, JE, Jr., Mantey, SA, and Jensen, RT 1994, A chimeric VIP-PACAP analogue but ...
Background-Endothelial dysfunction predisposes to vascular injury in association with hypertensio... more Background-Endothelial dysfunction predisposes to vascular injury in association with hypertension. Endothelin (ET-1) is a potent vasoactive peptide that is synthesized and released by the vascular endothelium and is a marker of endothelial function. Chromogranin A (CHGA) regulates the storage and release of catecholamines and may have direct actions on the microvasculature. CHGA, a candidate gene for intermediate phenotypes that contribute to hypertension, shows a pattern of single nucleotide polymorphism variations that alter the expression and function of this gene both in vivo and in vitro. Methods and Results-In a study of twins (nϭ238 pairs), plasma ET-1 was 58Ϯ5% (PϽ0.0001) heritable. Plasma ET-1 was both correlated and associated with chromogranin fragment levels, and the 2 were influenced by shared genetic determination (pleiotropy [ G ]; for the CHGA precursor, G ϭ0.318Ϯ0.105; Pϭ0.0032). We therefore hypothesized that variation in the CHGA gene may influence ET-1 secretion. Carriers of the CHGA promoter Ϫ988G, Ϫ462A, and Ϫ89A minor alleles showed significantly higher mean plasma ET-1 than their major allele homozygote counterparts (Pϭ0.02, Pϭ0.006, Pϭ0.03, respectively). Analysis of a linkage disequilibrium block that spans these 3 single nucleotide polymorphisms showed a significant association between the GATACA haplotype and plasma ET-1 (Pϭ0.0075). In cultured human umbilical vein endothelial cells, CHGA caused dose-dependent secretion of ET-1 over a brief (Ͻ1 hour) time course at relatively low concentrations of CHGA (10 to 100 nmol/L) with a threshold concentration (10 nmol/L) in the range found circulating in humans in vivo. Conclusions-These results suggest that common, heritable variation in expression of the human CHGA gene influences endothelial ET-1 secretion in vivo, explained by a CHGA stimulus/ET-1 secretion coupling in endothelial cells in vitro. The findings document a previously unsuspected interaction between the sympathochromaffin system and the endothelium and suggest novel genetic and cell biological approaches to the prediction, diagnosis, and mechanism of endothelial dysfunction in human disease. (Circulation. 2007;115:2282-2291.)
Pituitary adenylyl cyclase-activating polypeptide (PACAP) is a potent endogenous secretagogue for... more Pituitary adenylyl cyclase-activating polypeptide (PACAP) is a potent endogenous secretagogue for chromaffin cells. We previously reported that PACAP coupled to the PAC1 receptor to evoke dihydropyridine-sensitive early (15 to 20 minutes) catecholamine secretion and cAMP response element binding protein-mediated trans-activation of the secretory protein chromogranin A promoter in PC12 pheochromocytoma cells. In this report, we studied whether the secretory and transcriptional responses elicited by PACAP were subject to desensitization. We found that PACAP evoked distinct immediate (initial, 0 to 20 minutes) and long-lasting (20 to 180 minutes) effects on catecholamine secretion. Initial secretory and chromogranin A trans-activation responses induced by PACAP were desensitized in a dose-dependent fashion after preexposure of cells to PACAP, and the IC 50 doses of PACAP for desensitization were Ϸ18to Ϸ32-fold lower than the EC 50 activating doses for secretion or transcription. Desensitization of the initial secretion response was associated with decreased Ca 2ϩ influx through L-type voltage-operated Ca 2ϩ channels. Acute exposure to PACAP also triggered long-lasting (up to 3 hours), extracellular Ca 2ϩ -dependent, pertussis toxin-insensitive catecholamine secretion; indeed, even after short-term (20 minutes) exposure to PACAP and removal of the secretagogue, PC12 cells continued to secrete norepinephrine up to 76.9Ϯ0.22% of cellular norepinephrine content after 3 hours. A phospholipase C- inhibitor (U-73122) blocked this extended secretory response, which was dependent on low-magnitude Ca 2ϩ influx resistant to several L-, N-, P/Q-, or T-type Ca 2ϩ channel antagonists, but sensitive to Zn 2ϩ , Ni 2ϩ , Cd 2ϩ , or to the store-operated Ca 2ϩ channel blocker SKF96365. A less than additive effect of the sarcoendoplasmic reticulum Ca 2ϩ -ATPase inhibitor thapsigargin plus PACAP on this sustained secretion also supported a contribution of store-operated Ca 2ϩ entry to the sustained secretory response. We propose that PACAP-evoked secretion and transcription are subject to homologous desensitization in PC12 cells; however, PACAP also induces long-lasting secretion, even under dose and time circumstances in which acute, dihydropyridine-sensitive secretion has been desensitized. Although initial secretion is mediated by an L-type voltage-operated Ca 2ϩ channel, extended secretion may involve a store-operated Ca 2ϩ channel that is activated through a G q/11 /phospholipase C-/phosphoinositide signaling pathway. (Hypertension. 1999;34:1152-1162.)
Activation of protein kinase C (PKC) stimulates nicotine-induced catecholamine secretion. PKC dow... more Activation of protein kinase C (PKC) stimulates nicotine-induced catecholamine secretion. PKC down-regulation by prolonged pretreatment with phorbol 12-myristate 13-acetate diminished nicotine-induced catecholamine secretion only slightly (approximately 16%), suggesting substantial PKC independence of nicotinic receptor activation. However, we found that bisindolylmaleimide compounds (which are also putative PKC chemical inhibitors) dramatically inhibited nicotine-induced catecholamine secretion (IC(50) values of approximately 24-37 nM). This inhibition was specific for the nicotinic cholinergic receptor. Catecholamine secretion induced by other nicotinic agonists (such as epibatidine, anatoxin, or cytisine) was also powerfully antagonized by bisindolylmaleimide II (IC(50) values of approximately 60-90 nM). Even high-dose nicotinic agonists failed to overcome the inhibition by bisindolylmaleimide II, suggesting noncompetitive nicotinic antagonism by this class of compounds. Nicotini...
Dopamine beta-hydroxylase (DBH) is the biosynthetic enzyme catalyzing formation of norepinephrine... more Dopamine beta-hydroxylase (DBH) is the biosynthetic enzyme catalyzing formation of norepinephrine. Changes in DBH expression or activity have been implicated in the pathogenesis of cardiovascular and neuropsychiatric disorders. Genetic determination of DBH enzymatic activity and its secretion are only incompletely understood. We began with a genome-wide association search for loci contributing to DBH activity in human plasma. Initially, in a population sample of European ancestry, we identified the proximal DBH promoter as a region harboring three common trait-determining variants (top hit rs1611115, P = 7.2 × 10(-51)). We confirmed their effects on transcription and showed that the three variants each acted additively on gene expression. Results were replicated in a population sample of Native American descent (top hit rs1611115, P = 4.1 × 10(-15)). Jointly, DBH variants accounted for 57% of DBH trait variation. We further identified a genome-wide significant SNP at the LOC338797 l...
The molecular basis of neuroendocrine-specific expression of chromogranin B gene (Chgb) has remai... more The molecular basis of neuroendocrine-specific expression of chromogranin B gene (Chgb) has remained elusive. Utilizing wild-type and mutant Chgb promoter/luciferase reporter constructs, this study established a crucial role for the cAMP response element (CRE) box at )102/)95 bp in endocrine [rat pheochromocytoma (chromaffin) cell line (PC12) and rat pituitary somatotrope cell line (GC)] and neuronal [rat dorsal root ganglion/mouse neuroblastoma hybrid cell line (F-11), cortical and hippocampal primary neurons] cells. Additionally, G/C-rich domains at )134/)127, )125/)117 and )115/)110 bp played especially important roles for endocrine-specific expression of the Chgb gene. Co-transfection of expression plasmids for CREB, activator protein-2 (transcription factor) (AP-2), early growth response protein (transcription factor) (Egr-1) or specificity protein 1 (transcription factor) (Sp1) with the Chgb promoter constructs trans-activated expression of the Chgb gene. Nuclear extracts from either PC12 or F-11 cells formed specific complexes with the Chgb ()110/)87 bp) (CRE) oligonucleotide, which were either supershifted or disrupted by anti-CREB antibodies. In addition PC12 nuclear extracts also formed a specific complex with a Chgb ()140/)104-bp) oligonucleotide containing three G/C-rich regions, which was dose-dependently disrupted by anti-AP-2, anti-Egr-1 or anti-Sp1 antibodies; indeed, any one of these three antibodies completely abolished the complex, suggesting that all three factors bind the region simultaneously, at least in vitro. Chromatin immunoprecipitation assays documented the binding of the transcription factors CREB, AP-2, Egr-1 and Sp1 to the chromosomal Chgb gene promoter in vivo in PC12 cells within the context of chromatin. We conclude that the neuroendocrine-specific expression of Chgb is mediated by the CRE and G/C boxes in cis and the transcription factors CREB, AP-2, Egr-1 and Sp1 in trans.
Chromogranins or secretogranins (granins), present in secretory granules of virtually all neuroen... more Chromogranins or secretogranins (granins), present in secretory granules of virtually all neuroendocrine cells and neurones, are structurally related proteins encoded by different genetic loci: chromogranins A and B, and secretogranins II through VI. Compelling evidence supports both intracellular and extracellular functions for this protein family. Within the cells of origin, a granulogenic or sorting role in the regulated pathway of hormone or neurotransmitter secretion has been documented, especially for chromogranin A (CHGA). Granins also function as pro-hormones, giving rise by proteolytic processing to an array of peptide fragments for which diverse autocrine, paracrine, and endocrine activities have been demonstrated. CHGA measurements yield insight into the pathogenesis of such human diseases as essential hypertension, in which deficiency of the catecholamine release-inhibitory CHGA fragment catestatin may trigger sympathoadrenal overactivity as an aetiologic culprit in the syndrome. The CHGA dysglycaemic fragment pancreastatin is functional in humans in vivo, affecting both carbohydrate (glucose) and lipid (fatty acid) metabolism. Pancreastatin is cleaved from CHGA in hormone storage granules in vivo, and its plasma concentration varies in human disease. The pancreastatin region of CHGA gives rise to three naturally occurring human variants, one of which (Gly297Ser) occurs in the functionally important carboxy-terminus of the peptide, and substantially increases the peptide's potency to inhibit cellular glucose uptake. These observations establish a role for pancreastatin in human intermediary metabolism and disease, and suggest that qualitative hereditary alterations in pancreastatin's primary structure may give rise to interindividual differences in glucose disposition.
Previous modeling (PDB 1cfk) of the catecholamine release-inhibitory &amp... more Previous modeling (PDB 1cfk) of the catecholamine release-inhibitory "catestatin" region of chromogranin A (CgA) suggested a beta-strand/loop/beta-strand active conformation, displaying an electropositive Arg-rich loop (R(351)AR(353)GYGFR(358)). To explore this possibility, we studied NMR structures of linear and cyclic synthetic catestatin, bovine (bCgA(344-364)) or human (hCgA(352-372)). By 2-D (1)H-NMR, the structure of linear catestatin (hCgA(352-372)) exhibited the NOE pattern of a coiled loop (PDB 1lv4). We then constrained the structure, cyclizing the putative Arg-rich loop connecting the beta-strands: cyclic bCgA(350-362) ([C(0)]F(350)RARGYGFRGPGL(362)[C(+14)]). Favored conformations of cyclic bCgA(350-362) were determined by (1)H-NMR and (13)C-NMR spectroscopy. Cyclic bCgA(350-362) conformers (PDB 1n2y) adopted a…
Background: Elevated sympathetic activity is associated with kidney dysfunction. Here we used twi... more Background: Elevated sympathetic activity is associated with kidney dysfunction. Here we used twin pairs to probe heritability of GFR and its genetic covariance with other traits.
Journal of the American College of Cardiology, 2014
This study coupled 2 strategiesdtrait extremes and genome-wide poolingdto discover a novel blood ... more This study coupled 2 strategiesdtrait extremes and genome-wide poolingdto discover a novel blood pressure (BP) locus that encodes a previously uncharacterized thiamine transporter.
C-reactive protein (CRP) both reflects and participates in inflammation, and its circulating conc... more C-reactive protein (CRP) both reflects and participates in inflammation, and its circulating concentration marks cardiovascular risk. Here we sought to understand the role of heredity in determining CRP secretion. CRP, as well as multiple facets of the metabolic syndrome, were measured in a series of 229 twins, both monozygotic (MZ) and dizygotic (DZ), to estimate trait heritability (h2). Single nucleotide polymorphism (SNP) genotyping was done at adrenergic pathway loci. Haplotypes were inferred from genotypes by likelihood methods. Association of CRP with hypertension and the metabolic syndrome was studied in a larger series of 732 individuals, including 79 with hypertension. MZ and DZ twin variance components indicated substantial h2 for CRP, at approximately 56 +/- 7% (P < 0.001). CRP was significantly associated (P < 0.05) with multiple features of the metabolic syndrome in twins, including body mass index (BMI), blood pressure (BP), leptin and lipids. In established hypertension, elevated CRP was associated with increased BP, BMI, insulin, HOMA (index of insulin resistance), leptin, triglycerides and norepinephrine. Twin correlations indicated pleiotropy (shared genetic determination) for CRP with BMI (P = 0.0002), leptin (P < 0.001), triglycerides (P = 0.002) and systolic blood pressure (SBP) (P = 0.042). Approximately 9800 genotypes (43 genetic variants at 17 loci) were scored within catecholaminergic pathways: biosynthetic, receptor and signal transduction. Plasma CRP concentration in twins was predicted by polymorphisms at three loci in physiological series within the catecholamine biosynthetic/beta-adrenergic pathway: TH (tyrosine hydroxylase), ADRB1 (beta1-adrenergic receptor) and ADRB2 (beta2-adrenergic receptor). In the TH promoter, common allelic variation accounted for up to approximately 6.6% of CRP inter-individual variance. At ADRB1, variation at Gly389Arg predicted approximately 2.8% of CRP, while ADRB2 promoter variants T-47C and T-20C also contributed. Particular haplotypes and diplotypes at TH and ADRB1 also predicted CRP, though typically no better than single SNPs alone. Epistasis (gene-by-gene interaction) was demonstrated for particular combinations of TH and ADRB2 alleles, consistent with their actions in a pathway in series. In an illustration of pleiotropy, not only CRP but also plasma triglycerides were predicted by…
The mRNA levels of secretogranin II, chromogranin B, and VGF were compared in brains of control a... more The mRNA levels of secretogranin II, chromogranin B, and VGF were compared in brains of control and AF64A-treated rats. This toxin induces specific lesions of the septohippocampal cholinergic pathway. As a consequence of this treatment, the chromoaranin B message was elevated in the dentate gyrus grarlule cells of the hippocampus. In the paraventricular nucleus of the hypothalamus, a concomitant elevation of the messages of secretogranin II and corticotropin-releasing factor occurred in the parvocellular neurons, and an increase of those of secretogranin II and VGF occurred in a subgroup of magnocellular neurons. Further increases for secretogranin II were seen in the amygdaloid nuclei and the reticular thalamic nuclei and increases for chromogranin B in the temporal cortex, substantia nigra compacta, and ventral tegmental area. These results indicate that the toxin-induced lesion of the cholinergic pathway innervating the hippocampus apparently leads to the stimulation of several defined groups of neurons that react with an increase in the mRNA levels of their secretory peptides. We suggest that changes in mRNA expression of these peptides are useful parameters for defining neurons under chronic stimulation. Key Words: Secretory peptides-Large dense core vesicles -Corticotropinreleasing factor -Septohippocampal cholinergic system-Hippocampus-AF64A.
BACKGROUNDThe Seventh Joint National Committee on Prevention, Detection, Evaluation, and Treatmen... more BACKGROUNDThe Seventh Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure in 2003 created a prehypertension category for persons with blood pressures ranging from systolic blood pressure (SBP) of 120–139 mm Hg or diastolic blood pressure (DBP) from 80 to 89 mm Hg, due to increased risk of cardiovascular disease.METHODSOur study utilized the University of California-San Diego (UCSD) Twin Hypertension Cohort. We measured comprehensive plasma cholesterol levels and metabolic (glucose, insulin, leptin) and inflammatory markers (interleukin-6 (IL-6), C-reactive protein (CRP), free fatty acids) to determine the differences between normotensive and prehypertensive subjects. Additionally, we determined whether angiotensin II receptor type-1 (AGTR1) polymorphisms, previously associated with hypertension, could predict prehypertension.RESULTSA total of 455 white subjects were included in the study (mean age 37.1 years). Prehypertensive subjects were older with greater body mass index (BMI) than the normotensives, and after adjusting for sex and age, had greater plasma glucose, insulin, and IL-6. The common AGTR1 A1166C (rs5186) polymorphism in the 3′-UTR region, particularly the presence of the 1166C allele, which fails to downregulate gene expression, predicted greater likelihood of being in the prehypertension group and higher SBP. A lesser-studied polymorphism in intron-2 of AGTR1 (A/G; rs2276736) was associated with plasma high-density lipoprotein (HDL) and apolipoprotein A-1. In a subgroup analysis of nonobese subjects (N = 405), similar associations were noted.CONCLUSIONPrehypertensive subjects already exhibit early pathophysiologic changes putting them at risk of future cardiovascular disease, and AGTR1 may also contribute to this increased risk. Further investigation is needed to confirm these findings and the precise molecular mechanisms of action.
In 1997, we identified a novel peptide, catestatin (CST: bovine chromogranin A [CHGA] 344-364 : R... more In 1997, we identified a novel peptide, catestatin (CST: bovine chromogranin A [CHGA] 344-364 : RSMRLSFRARGYGFRGPGLQL; human CHGA 352-372 : SSMKLSFRARGYGFRGPGPQL), which is a potent inhibitor of nicotinic cholinergic-stimulated catecholamine secretion. CST shows characteristic inhibitory effects on nicotinic cationic (Na + , Ca 2+ ) signal transduction, which are specific to the neuronal nicotinic receptor. Utilizing systematic polymorphism discovery at the human CHGA locus we discovered three human variants of CST: G 364 S, P 370 L, and R 374 Q that showed differential potencies towards inhibition of catecholamine secretion. In humans, CHGA is elevated and its processing to CST is diminished in hypertension. Diminished CST is observed not only in hypertensive individuals but also early-normotensive offspring of patients with hypertension, suggesting that an early deficiency of CST might play a pathogenic role in the subsequent development of the disease. Consistent with human findings, prevention of endogenous CST expression by targeted ablation (knockout) of the mouse Chga locus (Chga-KO) resulted in severe hypertension that can be "rescued" specifically by replacement of the CST peptide. CST acts directly on the heart to inhibit the inotropic and lusitropic properties of the rodent heart and also acts as a potent vasodilator in rat and human. While the G 364 S CST variant caused profound changes in human autonomic activity and seemed to reduce risk of developing hypertension, CST replacement rescued Chga-KO mice from dampened baroreflex sensitivity. In addition, CST has been shown to induce chemotaxis and acts as an antimicrobial as well as an antimalarial peptide. The present review summarizes these multiple actions of CST.
Pituitary adenylyl cyclase activating polypeptide (PACAP) and vasoactive intestinal polypeptide (... more Pituitary adenylyl cyclase activating polypeptide (PACAP) and vasoactive intestinal polypeptide (VIP) augment the biosynthesis of tyrosine hydroxylase (TH). We tested whether secretin belonging to the glucagon/ PACAP/VIP superfamily would increase transcription of the tyrosine hydroxylase (Th) gene and modulate catecholamine secretion. Secretin activated transcription of the endogenous Th gene and its transfected promoter (EC 50 ∼4.6 nM) in pheochromocytoma (PC12) cells. This was abolished by pre-treatment with a secretin receptor (SCTR) antagonist and by inhibition of protein kinase A (PKA), mitogen-activated protein kinase, or CREB (cAMP response element-binding protein). In agreement, secretin increased PKA activity and induced phosphorylation of CREB and binding to Th CRE, suggesting secretin signaling to transcription via a PKA-CREB pathway. Secretin stimulated catecholamine secretion (EC 50 ∼3.5 μM) from PC12 cells, but this was inhibited by pre-treatment with VIP-preferring receptor (VPAC1)/PACAP-preferring receptor (PAC1) antagonists. Secretin-evoked secretion occurred without extracellular Ca 2+ and was abolished by intracellular Ca 2+ chelation. Secretin augmented phospholipase C (PLC) activity and increased inositol-1,4,5-triphosphate (IP 3 ) levels in PC12 cells; PLC-β inhibition blocked secretin-induced catecholamine secretion, indicating the participation of intracellular Ca 2+ from a phospholipase pathway in secretion. Like PACAP, secretin evoked long-lasting catecholamine secretion, even after only a transient exposure. Thus, transcription is triggered by nanomolar concentrations of the peptide through SCTR, with signaling along the cAMP-PKA and extracellular-signal-regulated kinase 1/2 pathways and through CREB. By contrast, secretion is triggered only by micromolar concentrations of peptide through PAC1/VPAC receptors and by utilizing a PLC/intracellular Ca 2+ pathway.
Hypertension and its related increase in cardiovascular morbidity in postmenopausal women is a ma... more Hypertension and its related increase in cardiovascular morbidity in postmenopausal women is a major public health problem. The hypotensive property of urinary kallikrein has been described since 1909. Despite the controversy surrounding the effects of hormone replacement therapy on blood pressure regulation, its mechanisms remain incompletely understood, and no evidence has yet been provided for its effects on renal kallikrein excretion in postmenopausal women.
Obesity is a heritable trait that contributes to hypertension and subsequent cardiorenal disease ... more Obesity is a heritable trait that contributes to hypertension and subsequent cardiorenal disease risk; thus, the investigation of genetic variation that predisposes individuals to obesity is an important goal. Circulating peptide YY (PYY) is known for its appetite and energy expenditure-regulating properties; linkage and association studies have suggested that PYY genetic variation contributes to susceptibility for obesity, rendering PYY an attractive candidate for study of disease risk. To explore whether common genetic variation at the human PYY locus influences plasma PYY or metabolic traits, we systematically resequenced the gene for polymorphism discovery and then genotyped common single-nucleotide polymorphisms across the locus in an extensively phenotyped twin sample to determine associations. Finally, we experimentally validated the marker-on-trait associations using PYY 3'-untranslated region (UTR)/reporter and promoter/reporter analyses in neuroendocrine cells. Four common genetic variants were discovered across the locus, and three were typed in phenotyped twins. Plasma PYY was highly heritable (P < 0.0001), and genetic pleiotropy was noted between plasma PYY and body mass index (BMI) (P = 0.03). A PYY haplotype extending from the proximal promoter (A-23G, rs2070592) to the 3'-UTR (C+1134A, rs162431) predicted not only plasma PYY (P = 0.009) but also other metabolic syndrome traits. Functional studies with transfected luciferase reporters confirmed regulatory roles in altering gene expression for both 3'-UTR C+1134A (P < 0.001) and promoter A-23G (P = 0.0016). Functional genetic variation at the PYY locus influences multiple heritable metabolic syndrome traits, likely conferring susceptibility to obesity and subsequent cardiorenal disease.
Secretoneurin is a peptide of 33 amino acids generated in brain by proteolytic processing of secr... more Secretoneurin is a peptide of 33 amino acids generated in brain by proteolytic processing of secretogranin 11. The distribution of this newly characterized peptide was investigated by means of immunocytochemistry and in situ hybridization in the spinal cord and lower brainstem of the rat. The staining pattern of secretoneurin immunoreactivity (IR) was compared to that of substance P (SP) and calcitonin gene-related peptide (CGRP) in adjacent sections. A high density of secretoneurin-IR fibers and terminals was found in lamina I and outer lamina I1 of the caudal trigeminal nucleus and of the spinal cord a t all levels, around the central canal, and in the sympathetic and parasympathetic areas of the lateral cell columns. The ventral horn displayed a low to moderate density of secretoneurin-IR. The highest number of secretogranin I1 mRNA-containing cells was found in lamina I1 of the dorsal horn and in neurons of the dorsal root ganglia. In the white matter, secretoneurin-IR was most prominent in the dorsolateral part of the lateral funiculus and in the tract of Lissauer. The distributions of secretoneurin-IR and SP-IR were strikingly similar. CGRP-IR and secretoneurin-IR overlapped in the outer laminae of the dorsal horn, in the lateral cell column, and probably in some motoneurons. This study establishes that, like SP and CGRP, secretoneurin is a peptide highly concentrated in the terminal field of primary afferents and in sympathetic and parasympathetic areas. Thus secretoneurin might be involved in the modulation of afferent transmission.
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Papers by Manjula Mahata