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Kawaida M, Abe T, Nakanishi T, Miyahara Y, Yamagishi H, Sakamoto M, Yamada T. A case of Timothy syndrome with adrenal medullary dystrophy. Pathol Int 2016; 66:587-592. [PMID: 27593853 DOI: 10.1111/pin.12456] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 08/07/2016] [Accepted: 08/15/2016] [Indexed: 11/30/2022]
Abstract
Timothy syndrome (TS) is a congenital long QT syndrome that is associated with syndactyly and mutations in CACNA1C, encoding an L-type voltage-dependent calcium channel, Cav1.2. Recently, TS has been associated with autism and other psychological disorders. This case indicated bradycardia by prenatal screening and was diagnosed as TS by the occurrence of syndactyly and QT prolongation at birth. Despite therapy with anti-arrhythmia reagents and a pacemaker, the patient died 2 months after birth and was autopsied. The heart showed mild dilation and mild hypertrophy with a focal disarray pattern, which may be inconsistent with typical cardiomyopathy. Unexpectedly, bilateral adrenal glands showed marked shrinkage and severe fibrosis of the medulla with a small number of single-strand DNA positive medullary cells and accumulation of hemosiderin-containing macrophages. This finding suggests that CACNA1C mutation may induce drop-out of medulla cells via apoptosis. This may be due to increased concentration of calcium ions consistent with Cav1.2 expression in adrenal glands as well as in the brain and the heart. This is the first report describing a systemic autopsy of TS with adrenal medullary dystrophy.
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Affiliation(s)
- Miho Kawaida
- Department of Pathology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, Japan.,Divion of Diagnostic Pathology, Keio University Hospital, 35 Shinanomachi, Shinjuku-ku, Tokyo, Japan
| | - Tokiya Abe
- Department of Pathology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, Japan
| | - Toshio Nakanishi
- Department of Pediatric Cardiology, Tokyo Women's Medical University, 8-1, Kawada-cho, Shinjuku-ku, Tokyo, Japan
| | - Yoko Miyahara
- Department of Pediatrics, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, Japan
| | - Hiroyuki Yamagishi
- Department of Pediatrics, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, Japan
| | - Michiie Sakamoto
- Department of Pathology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, Japan
| | - Taketo Yamada
- Department of Pathology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, Japan. .,Department of Pathology, Saitama Medical University, 38 Morohongo, Moroyamacho, Iruma, Saitama, Japan.
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Momboisse F, Olivares MJ, Báez-Matus X, Guerra MJ, Flores-Muñoz C, Sáez JC, Martínez AD, Cárdenas AM. Pannexin 1 channels: new actors in the regulation of catecholamine release from adrenal chromaffin cells. Front Cell Neurosci 2014; 8:270. [PMID: 25237296 PMCID: PMC4154466 DOI: 10.3389/fncel.2014.00270] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 08/20/2014] [Indexed: 11/13/2022] Open
Abstract
Chromaffin cells of the adrenal gland medulla synthesize and store hormones and peptides, which are released into the blood circulation in response to stress. Among them, adrenaline is critical for the fight-or-flight response. This neurosecretory process is highly regulated and depends on cytosolic [Ca2+]. By forming channels at the plasma membrane, pannexin-1 (Panx1) is a protein involved in many physiological and pathological processes amplifying ATP release and/or Ca2+ signals. Here, we show that Panx1 is expressed in the adrenal gland where it plays a role by regulating the release of catecholamines. In fact, inhibitors of Panx1 channels, such as carbenoxolone (Cbx) and probenecid, reduced the secretory activity induced with the nicotinic agonist 1,1-dimethyl-4-phenyl-piperazinium (DMPP, 50 μM) in whole adrenal glands. A similar inhibitory effect was observed in single chromaffin cells using Cbx or 10Panx1 peptide, another Panx1 channel inhibitors. Given that the secretory response depends on cytosolic [Ca2+] and Panx1 channels are permeable to Ca2+, we studied the possible implication of Panx1 channels in the Ca2+ signaling occurring during the secretory process. In support of this possibility, Panx1 channel inhibitors significantly reduced the Ca2+ signals evoked by DMPP in single chromaffin cells. However, the Ca2+ signals induced by caffeine in the absence of extracellular Ca2+ was not affected by Panx1 channel inhibitors, suggesting that this mechanism does not involve Ca2+ release from the endoplasmic reticulum. Conversely, Panx1 inhibitors significantly blocked the DMPP-induce dye uptake, supporting the idea that Panx1 forms functional channels at the plasma membrane. These findings indicate that Panx1 channels participate in the control the Ca2+ signal that triggers the secretory response of adrenal chromaffin cells. This mechanism could have physiological implications during the response to stress.
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Affiliation(s)
- Fanny Momboisse
- Centro Interdisciplinario de Neurociencias de Valparaíso, Universidad de Valparaíso Valparaíso, Chile
| | - María José Olivares
- Centro Interdisciplinario de Neurociencias de Valparaíso, Universidad de Valparaíso Valparaíso, Chile
| | - Ximena Báez-Matus
- Centro Interdisciplinario de Neurociencias de Valparaíso, Universidad de Valparaíso Valparaíso, Chile
| | - María José Guerra
- Centro Interdisciplinario de Neurociencias de Valparaíso, Universidad de Valparaíso Valparaíso, Chile
| | - Carolina Flores-Muñoz
- Centro Interdisciplinario de Neurociencias de Valparaíso, Universidad de Valparaíso Valparaíso, Chile
| | - Juan C Sáez
- Centro Interdisciplinario de Neurociencias de Valparaíso, Universidad de Valparaíso Valparaíso, Chile ; Departamento de Fisiología, Pontifícia Universidad Católica de Chile Santiago, Chile
| | - Agustín D Martínez
- Centro Interdisciplinario de Neurociencias de Valparaíso, Universidad de Valparaíso Valparaíso, Chile
| | - Ana M Cárdenas
- Centro Interdisciplinario de Neurociencias de Valparaíso, Universidad de Valparaíso Valparaíso, Chile
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Durán-Pastén ML, Fiordelisio T. GnRH-Induced Ca(2+) Signaling Patterns and Gonadotropin Secretion in Pituitary Gonadotrophs. Functional Adaptations to Both Ordinary and Extraordinary Physiological Demands. Front Endocrinol (Lausanne) 2013; 4:127. [PMID: 24137156 PMCID: PMC3786263 DOI: 10.3389/fendo.2013.00127] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2013] [Accepted: 08/31/2013] [Indexed: 11/13/2022] Open
Abstract
PITUITARY GONADOTROPHS ARE A SMALL FRACTION OF THE ANTERIOR PITUITARY POPULATION, YET THEY SYNTHESIZE GONADOTROPINS: luteinizing (LH) and follicle-stimulating (FSH), essential for gametogenesis and steroidogenesis. LH is secreted via a regulated pathway while FSH release is mostly constitutive and controlled by synthesis. Although gonadotrophs fire action potentials spontaneously, the intracellular Ca(2+) rises produced do not influence secretion, which is mainly driven by Gonadotropin-Releasing Hormone (GnRH), a decapeptide synthesized in the hypothalamus and released in a pulsatile manner into the hypophyseal portal circulation. GnRH binding to G-protein-coupled receptors triggers Ca(2+) mobilization from InsP3-sensitive intracellular pools, generating the global Ca(2+) elevations necessary for secretion. Ca(2+) signaling responses to increasing (GnRH) vary in stereotyped fashion from subthreshold to baseline spiking (oscillatory), to biphasic (spike-oscillatory or spike-plateau). This progression varies somewhat in gonadotrophs from different species and biological preparations. Both baseline spiking and biphasic GnRH-induced Ca(2+) signals control LH/FSH synthesis and exocytosis. Estradiol and testosterone regulate gonadotropin secretion through feedback mechanisms, while FSH synthesis and release are influenced by activin, inhibin, and follistatin. Adaptation to physiological events like the estrous cycle, involves changes in GnRH sensitivity and LH/FSH synthesis: in proestrus, estradiol feedback regulation abruptly changes from negative to positive, causing the pre-ovulatory LH surge. Similarly, when testosterone levels drop after orquiectomy the lack of negative feedback on pituitary and hypothalamus boosts both GnRH and LH secretion, gonadotrophs GnRH sensitivity increases, and Ca(2+) signaling patterns change. In addition, gonadotrophs proliferate and grow. These plastic changes denote a more vigorous functional adaptation in response to an extraordinary functional demand.
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Affiliation(s)
- Maria Luisa Durán-Pastén
- Departamento de Neurociencia Cognitiva, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México (UNAM), México DF, México
| | - Tatiana Fiordelisio
- Departamento de Ecología y Recursos Naturales, Facultad de Ciencias, Universidad Nacional Autónoma de México (UNAM), México DF, México
- *Correspondence: Tatiana Fiordelisio, Departamento de Ecología y Recursos Naturales, Facultad de Ciencias, Universidad Nacional Autónoma de México (UNAM), Circuito exterior s/n. Ciudad Universitaria, C.P. 04510 México DF, México e-mail:
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