1
|
Pineros J, Zhu X, Ding B, Frisina RD. Connexins 30 and 43 expression changes in relation to age-related hearing loss. Hear Res 2024; 444:108971. [PMID: 38359484 PMCID: PMC10939722 DOI: 10.1016/j.heares.2024.108971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 01/27/2024] [Accepted: 02/10/2024] [Indexed: 02/17/2024]
Abstract
Age-related hearing loss (ARHL), also known as presbycusis, is the number one communication disorder for aging adults. Connexin proteins are essential for intercellular communication throughout the human body, including the cochlea. Mutations in connexin genes have been linked to human syndromic and nonsyndromic deafness; thus, we hypothesize that changes in connexin gene and protein expression with age are involved in the etiology of ARHL. Here, connexin gene and protein expression changes for CBA/CaJ mice at different ages were examined, and correlations were analyzed between the changes in expression levels and functional hearing measures, such as ABRs and DPOAEs. Moreover, we investigated potential treatment options for ARHL. Results showed significant downregulation of Cx30 and Cx43 gene expression and significant correlations between the degree of hearing loss and the changes in gene expression for both genes. Moreover, dose-dependent treatments utilizing cochlear cell lines showed that aldosterone hormone therapy significantly increased Cx expression. In vivo mouse treatments with aldosterone also showed protective effects on connexin expression in aging mice. Based on these functionally relevant findings, next steps can include more investigations of the mechanisms related to connexin family gap junction protein expression changes during ARHL; and expand knowledge of clinically-relevant treatment options by knowing what specific members of the Cx family and related inter-cellular proteins should be targeted therapeutically.
Collapse
Affiliation(s)
- Jennifer Pineros
- Department of Medical Engineering, College of Engineering, University of South Florida, Tampa, FL 33620, USA; Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL 33612, USA
| | - Xiaoxia Zhu
- Department of Medical Engineering, College of Engineering, University of South Florida, Tampa, FL 33620, USA; Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL 33612, USA
| | - Bo Ding
- Department of Medical Engineering, College of Engineering, University of South Florida, Tampa, FL 33620, USA; Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL 33612, USA
| | - Robert D Frisina
- Department of Medical Engineering, College of Engineering, University of South Florida, Tampa, FL 33620, USA; Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL 33612, USA; Department of Communication Sciences and Disorders, College of Behavioral & Community Sciences, University of South Florida, Tampa, FL 33620, USA; Morsani College of Medicine, University of South Florida, Tampa, FL 33620, USA.
| |
Collapse
|
2
|
Liu W, Chen H, Zhu X, Yu H. Expression of Calbindin-D28K in the Developing and Adult Mouse Cochlea. J Histochem Cytochem 2022; 70:583-596. [PMID: 35975307 PMCID: PMC9393511 DOI: 10.1369/00221554221119543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Herein, we aimed to use double-labeling immunofluorescence to describe the expression pattern of Calbindin-D28K (CaBP28K) in the mouse cochlea from late embryonic (E) stages to the adulthood. CaBP28K was expressed in the inner hair cells (IHCs) and the greater epithelial ridge (GER) at E17. In addition, its expression was observed in the interdental cells. On postnatal day 1 (P1), CaBP28K immunoreactivity was observed in the IHCs and outer hair cells (OHCs) and was also specifically expressed in the nucleus and the cytoplasm of spiral ganglion neurons (SGNs). At P8, CaBP28K labeling disappeared from the interdental cells, and the CaBP28K-positive domain within the GER shifted from the entire cytoplasm to only the apical and basal regions. At P14, CaBP28K immunoreactivity was lost from the GER; however, its expression in the IHCs and OHCs, as well as the SGNs, persisted into adulthood. The identification of CaBP28K in the hair cells (HCs) and cuticular plates, as well as SGNs, was confirmed by its colocalization with several markers for Sox2, Myosin VIIa, Phalloidin, and Tuj1. We also detected colocalization with calmodulin in the cytoplasm of both HCs and SGNs. Western blot revealed an increase in CaBP28K postnatal expression in the mouse cochlea.
Collapse
Affiliation(s)
- Wenjing Liu
- Department of Otorhinolaryngology-Head and Neck Surgery, Zhongda Hospital, Southeast University, Nanjing, China
| | - Huijun Chen
- Department of Otorhinolaryngology-Head and Neck Surgery, Zhongda Hospital, Southeast University, Nanjing, China
| | - Xin Zhu
- Department of Otorhinolaryngology-Head and Neck Surgery, Zhongda Hospital, Southeast University, Nanjing, China
| | - Hao Yu
- Anhui Province Key Laboratory of Biological Macro-Molecules Research, Wannan Medical College, Wuhu, China
| |
Collapse
|
3
|
Hearing Loss Caused by HCMV Infection through Regulating the Wnt and Notch Signaling Pathways. Viruses 2021; 13:v13040623. [PMID: 33917368 PMCID: PMC8067389 DOI: 10.3390/v13040623] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 03/31/2021] [Accepted: 04/01/2021] [Indexed: 01/27/2023] Open
Abstract
Hearing loss is one of the most prevalent sensory disabilities worldwide with huge social and economic burdens. The leading cause of sensorineural hearing loss (SNHL) in children is congenital cytomegalovirus (CMV) infection. Though the implementation of universal screening and early intervention such as antiviral or anti-inflammatory ameliorate the severity of CMV-associated diseases, direct and targeted therapeutics is still seriously lacking. The major hurdle for it is that the mechanism of CMV induced SNHL has not yet been well understood. In this review, we focus on the impact of CMV infection on the key players in inner ear development including the Wnt and Notch signaling pathways. Investigations on these interactions may gain new insights into viral pathogenesis and reveal novel targets for therapy.
Collapse
|
4
|
Wang J, Bai T, Wang N, Li H, Guo X. Neuroprotective potential of imatinib in global ischemia-reperfusion-induced cerebral injury: possible role of Janus-activated kinase 2/signal transducer and activator of transcription 3 and connexin 43. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2020; 24:11-18. [PMID: 31908570 PMCID: PMC6940502 DOI: 10.4196/kjpp.2020.24.1.11] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 06/18/2019] [Accepted: 06/20/2019] [Indexed: 12/20/2022]
Abstract
The present study was aimed to explore the neuroprotective role of imatinib in global ischemia-reperfusion-induced cerebral injury along with possible mechanisms. Global ischemia was induced in mice by bilateral carotid artery occlusion for 20 min, which was followed by reperfusion for 24 h by restoring the blood flow to the brain. The extent of cerebral injury was assessed after 24 h of global ischemia by measuring the locomotor activity (actophotometer test), motor coordination (inclined beam walking test), neurological severity score, learning and memory (object recognition test) and cerebral infarction (triphenyl tetrazolium chloride stain). Ischemia-reperfusion injury produced significant cerebral infarction, impaired the behavioral parameters and decreased the expression of connexin 43 and phosphorylated signal transducer and activator of transcription 3 (p-STAT3) in the brain. A single dose administration of imatinib (20 and 40 mg/kg) attenuated ischemia-reperfusion-induced behavioral deficits and the extent of cerebral infarction along with the restoration of connexin 43 and p-STAT3 levels. However, administration of AG490, a selective Janus-activated kinase 2 (JAK2)/STAT3 inhibitor, abolished the neuroprotective actions of imatinib and decreased the expression of connexin 43 and p-STAT3. It is concluded that imatinib has the potential of attenuating global ischemia-reperfusion-induced cerebral injury, which may be possibly attributed to activation of JAK2/STAT3 signaling pathway along with the increase in the expression of connexin 43.
Collapse
Affiliation(s)
- Jieying Wang
- Department of Pediatrics, Shaanxi Provincial People's Hospital, The Affiliated Hospital of Xi'an Medical University, The Third Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710068, Shaanxi, China
| | - Taomin Bai
- Department of Pediatrics, Shaanxi Provincial People's Hospital, The Affiliated Hospital of Xi'an Medical University, The Third Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710068, Shaanxi, China
| | - Nana Wang
- Central Laboratory, Shaanxi Provincial People's Hospital, The Affiliated Hospital of Xi'an Medical University, The Third Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710068, Shaanxi, China
| | - Hongyan Li
- Department of Pediatrics, Shaanxi Provincial People's Hospital, The Affiliated Hospital of Xi'an Medical University, The Third Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710068, Shaanxi, China
| | - Xiangyang Guo
- Department of Pediatrics, Shaanxi Provincial People's Hospital, The Affiliated Hospital of Xi'an Medical University, The Third Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710068, Shaanxi, China.,Department of Neurology, Xijing Hospital, Air Force Medical University, Xi'an 710032, Shaanxi, China
| |
Collapse
|
5
|
Zhang J, Wang X, Hou Z, Neng L, Cai J, Zhang Y, Shi X. Suppression of Connexin 43 Leads to Strial Vascular Hyper-Permeability, Decrease in Endocochlear Potential, and Mild Hearing Loss. Front Physiol 2020; 11:974. [PMID: 32922309 PMCID: PMC7457066 DOI: 10.3389/fphys.2020.00974] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 07/16/2020] [Indexed: 12/20/2022] Open
Abstract
Objective: Connexin 43 (Cx43) is a protein constituent of gap junctions (GJs) in various barrier cells, especially astrocytes and microglia of the blood-brain-barrier (BBB), where it plays an important role in intercellular communication and regulation of the barrier. Despite the importance of Cx43 in other blood barriers, not much attention has been paid to expression and function of Cx43 in the blood-labyrinth-barrier (BLB) of the stria vascularis in the cochlea. Methods: We used multiple research approaches, including immunocytochemical staining, patch-clamp dye loading technique, real-time quantitative reverse transcription (RT)-PCR, western blot, measurement of endocochlear potential (EP) with an electrode through the scala media, and auditory brainstem response to test hearing function. Results: We found Cx43 expressed in vascular endothelial cells (ECs) and perivascular resident macrophages (PVMs) in the stria vascularis of adult C57BL/6 mouse cochleae. In particular, we found Cx43 expressed in foot processes of PVMs at points of contact with the endothelium. Consistent with Cx43 expression in vivo, we also found Cx43 expressed in EC-EC and EC-PVM interfaces in a co-cultured cell line model. Using a patch-clamp dye loading technique, we demonstrated that Alexa Fluor® 568 dye injected into PVMs diffuses to connected neighboring ECs. The functional coupling between the ECs and PVMs is blocked by 18α-Glycyrrhetinic acid (18α-GA), a GJ blocker. Suppression of Cx43 with small interfering RNA (siRNA) in vivo significantly elevated hearing threshold and caused the EP to drop and the blood barrier to become more permeable. In further study, using in vitro primary EC cell line models, we demonstrated that suppression of Cx43 disrupts intercellular tight junctions (TJs) in the EC monolayer and increases endothelial monolayer permeability. Conculsion: Taken together, these findings underscore the importance of Cx43 expression in the normal ear for maintaining BLB integrity, normal EP, and hearing function.
Collapse
Affiliation(s)
- Jinhui Zhang
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR, United States
| | - Xiaohan Wang
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR, United States
- Boston Children’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Zhiqiang Hou
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR, United States
| | - Lingling Neng
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR, United States
| | - Jing Cai
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR, United States
| | - Yunpei Zhang
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR, United States
| | - Xiaorui Shi
- Oregon Hearing Research Center, Oregon Health & Science University, Portland, OR, United States
| |
Collapse
|
6
|
Berekméri E, Fekete Á, Köles L, Zelles T. Postnatal Development of the Subcellular Structures and Purinergic Signaling of Deiters' Cells along the Tonotopic Axis of the Cochlea. Cells 2019; 8:cells8101266. [PMID: 31627326 PMCID: PMC6830339 DOI: 10.3390/cells8101266] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/03/2019] [Accepted: 10/15/2019] [Indexed: 01/04/2023] Open
Abstract
Exploring the development of the hearing organ helps in the understanding of hearing and hearing impairments and it promotes the development of the regenerative approaches-based therapeutic efforts. The role of supporting cells in the development of the organ of Corti is much less elucidated than that of the cochlear sensory receptor cells. The use of our recently published method of single-cell electroporation loading of a fluorescent Ca2+ probe in the mouse hemicochlea preparation provided an appropriate means to investigate the Deiters’ cells at the subcellular level in two different cochlear turns (apical, middle). Deiters’ cell’s soma and process elongated, and the process became slimmer by maturation without tonotopic preference. The tonotopically heterogeneous spontaneous Ca2+ activity less frequently occurred by maturation and implied subcellular difference. The exogenous ATP- and UTP-evoked Ca2+ responses were maturation-dependent and showed P2Y receptor dominance in the apical turn. By monitoring the basic structural dimensions of this supporting cell type as well as its spontaneous and evoked purinergic Ca2+ signaling in the hemicochlea preparation in different stages in the critical postnatal P5-25 developmental period for the first time, we showed that the soma and the phalangeal process of the Deiters’ cells go through age- and tonotopy-dependent changes in the morphometric parameters and purinergic signaling.
Collapse
Affiliation(s)
- Eszter Berekméri
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Nagyvárad tér 4., 1089 Budapest, Hungary.
- Department of Ecology, University of Veterinary Medicine, Rottenbiller u. 50., 1077 Budapest, Hungary.
| | - Ádám Fekete
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, 555 University Ave, Toronto, ON M5G 1X8, Canada.
| | - László Köles
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Nagyvárad tér 4., 1089 Budapest, Hungary.
| | - Tibor Zelles
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Nagyvárad tér 4., 1089 Budapest, Hungary.
- Department of Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Szigony u. 43., 1083 Budapest, Hungary.
| |
Collapse
|
7
|
Liu W, Wang C, Yu H, Liu S, Yang J. Expression of acetylated tubulin in the postnatal developing mouse cochlea. Eur J Histochem 2018; 62. [PMID: 30088716 PMCID: PMC6119817 DOI: 10.4081/ejh.2018.2942] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 08/01/2018] [Indexed: 11/24/2022] Open
Abstract
Microtubules are an essential component of the cytoskeleton of a eukaryotic cell. The post-translational tubulin modifications play an important role in regulating microtubule properties, acetylation tubulin is one of the major post-translational modifications of microtubules. Acetylation tubulin has also been shown to be expressed in the cochlea. However, the detailed expression profiles of acetylation tubulin protein during development have not yet been investigated in the postnatal mammalian cochlea. Here, we first examined the spatio-temporal expression of acetylated tubulin in the mouse cochlea during postnatal development. At postnatal day 1 (P1), acetylated tubulin was localized primarily to the auditory nerve inside the cochlea and their synaptic contacts with the inner and outer hair cells (IHCs and OHCs). In the organ of Corti, acetylated tubulin occurred first at the apex of pillar cells. At P5, acetylated tubulin first appeared in the phalangeal processes of Deiters’ cells. At P8, staining was maintained in the phalangeal processes of Deiters’ cells and neural elements. At P10, labeling in Deiters’ cells extended from the apices of OHCs to the basilar membrane, acetylated tubulin was expressed throughout the cytoplasm of inner and outer pillar cells. At P12, acetylated tubulin displayed prominent and homogeneous labeling along the full length of the pillar cells. Linear labeling was present mainly in the Deiters’ cell bodies underlying OHCs. Between P14 and P17, acetylated tubulin was strongly expressed in inner and outer pillar cells and Deiters’ cells in a similar pattern as observed in the adult, and labeling in these cells were arranged in bundles. In addition, acetylated tubulin was expressed in stria vascularis, root cell bodies, and a small number of fibrocytes of the spiral ligament until the adult. In the adult mouse cochlea, immunostaining continued to predominate in Deiters’ cells and pillar cells. In Deiters’ cells, immunolabeling formed cups securing OHCs basal portions, and continued presence of acetylated tubulin-labeled nerve terminals below IHCs was shown. Our results presented here underscored the essential role played by acetylated tubulin in postnatal cochlear development, auditory neurotransmission and cochlear mechanics.
Collapse
Affiliation(s)
- Wenjing Liu
- Shanghai Jiaotong University Ear Institute, Department of Otorhinolaryngology-Head and Neck Surgery.
| | | | | | | | | |
Collapse
|
8
|
Abitbol JM, Kelly JJ, Barr KJ, Allman BL, Laird DW. Mice harbouring an oculodentodigital dysplasia-linked Cx43 G60S mutation have severe hearing loss. J Cell Sci 2018; 131:jcs.214635. [DOI: 10.1242/jcs.214635] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 03/27/2018] [Indexed: 01/22/2023] Open
Abstract
Given the importance of connexin43 (Cx43) function in the central nervous system and sensory organ processing we proposed that it would also be crucial in auditory function. To that end, hearing was examined in two mouse models of oculodentodigital dysplasia that globally express GJA1 (Cx43) mutations resulting in mild or severe loss of Cx43 function. Although Cx43I130T/+ mutant mice with ∼50% Cx43 channel function did not have any hearing loss, Cx43G60S/+ mutant mice with ∼20% Cx43 channel function had severe hearing loss. There was no evidence of inner ear sensory hair cell loss, suggesting that the Cx43-linked hearing loss lies downstream in the auditory pathway. Since evidence suggests that Cx26 function is essential for hearing and may be protective against noise-induced hearing loss, we challenged Cx43I130T/+ mice with a loud noise and found that they had similar susceptibility to noise-induced hearing loss as controls suggesting that decreased Cx43 function does not sensitize the mice for environmentally-induced hearing loss. Taken together, this study suggests that Cx43 plays an important role in baseline hearing and is essential for auditory processing.
Collapse
Affiliation(s)
| | - John J. Kelly
- University of Western Ontario, London, Ontario, Canada
| | - Kevin J. Barr
- University of Western Ontario, London, Ontario, Canada
| | | | - Dale W. Laird
- University of Western Ontario, London, Ontario, Canada
| |
Collapse
|
9
|
Liu J, Cai L, He Y, Yang J. Apoptosis pattern and alterations of expression of apoptosis-related factors of supporting cells in Kölliker's organ in vivo in early stage after birth in rats. Eur J Histochem 2017; 61:2706. [PMID: 29046047 PMCID: PMC5572717 DOI: 10.4081/ejh.2017.2706] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 06/21/2017] [Accepted: 06/21/2017] [Indexed: 11/23/2022] Open
Abstract
Kolliker’s organ is a temporary but indispensable structure in the development of the cochlea. Supporting cells (SCs) within it release adenosine 5’-triphosphate (ATP), which may play a crucial role in cochlear development before the onset of hearing. To reveal the apoptosis of Kolliker’s organ in new-born rats, we studied the morphological changes and expression of apoptosis-related factors during early postnatal development. We found SCs in Kolliker’s organ decreased in number and changed in appearance along the cochlea apex-to-base gradient, and the expression of caspase-3, caspase-8, caspase- 9 and bcl-2 in Kolliker’s organ of the cochlea fluctuated along the course of postnatal development, with an expression peak at postnatal day 3. This study demonstrates a time-dependent degeneration of Kolliker’s organ during postnatal cochlea development, which might be triggered by endogenous factors.
Collapse
Affiliation(s)
- Jun Liu
- Shanghai Jiaotong University School of Medicine.
| | | | | | | |
Collapse
|
10
|
Pellicciari C. Is there still room for novelty, in histochemical papers? Eur J Histochem 2016; 60:2758. [PMID: 28076939 PMCID: PMC5381530 DOI: 10.4081/ejh.2016.2758] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Accepted: 12/15/2016] [Indexed: 12/11/2022] Open
Abstract
Histochemistry continues to be widely applied in biomedical research, being nowadays mostly addressed to detect and locate single molecules or molecular complexes inside cells and tissues, and to relate structural organization and function at the high resolution of the more advanced microscopical techniques. In the attempt to see whether histochemical novelties may be found in the recent literature, the articles published in the European Journal of Histochemistry in the period 2014-2016 have been reviewed. In the majority of the published papers, standardized methods have been preferred by scientists to make their results reliably comparable with the data in the literature, but several papers (approximately one fourth of the published articles) described novel histochemical methods and procedures. It is worth noting that there is a growing interest for minimally-invasive in vivo techniques (magnetic resonance imaging, autofluorescence spectroscopy), which may parallel conventional histochemical analyses to acquire evidence not only on the morphological features of living organs and tissues, but also on their functional, biophysical and molecular characteristics. Thanks to this unceasing methodological refinement, histochemistry will continue to provide innovative applications in the biomedical field.
Collapse
|
11
|
Soares ES, Mendonça MCP, Rocha T, Kalapothakis E, da Cruz-Höfling MA. Are Synchronized Changes in Connexin-43 and Caveolin-3 a Bystander Effect in a Phoneutria nigriventer Venom Model of Blood-Brain Barrier Breakdown? J Mol Neurosci 2016; 59:452-63. [PMID: 27067308 DOI: 10.1007/s12031-016-0749-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 03/23/2016] [Indexed: 12/17/2022]
Abstract
Upregulation of caveolin-3 (Cav-3) or connexin-43 (Cx43) in astrocytes has been associated with important brain pathologies. We used Phoneutria nigriventer spider venom (PNV), which induces blood-brain barrier breakdown in rats, in order to investigate Cav-3 and Cx43 expression in the cerebellum over critical periods of rat envenomation. By immunofluorescence, western blotting (WB), and transmission electron microscopy (TEM), we assessed changes at 1, 2, 5, 24, and 72 h post-venom. WB showed immediate increases in Cav-3 and Cx43 at 1 h (interval of greatest manifestations of envenomation) that persisted at 5 h (when there were signs of recovery) and peaked at 24 h when no signs of envenomation were detectable. At 2 and 72 h, Cav-3 was downregulated and Cx43 had returned to baseline. PNV markedly intensified Cx43 in molecular, Purkinje and granular layers and Cav-3 in astrocytes whose colocalization to increased GFAP suggests interaction between reactive astrogliosis and Cav-3 upregulation. TEM showed swollen perivascular astrocytic end-feet and synaptic contact alterations that had generally resolved by 72 h. It is uncertain whether such PNV-induced synchronized changes are an interactive effect between Cav-3 and Cx43, or a bystander effect. Evidences indicate that Cav-3 downregulation coupled to Cx43 return to baseline at 72 h when no signs of envenomation were visible, suggesting homeostasis reestablishment. This experimental model is relevant to studying mechanisms involved in neurological disorders associated with Cav-3 overexpression.
Collapse
Affiliation(s)
- Edilene Siqueira Soares
- Department of Biochemistry and Tissue Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Monique Culturato Padilha Mendonça
- Department of Biochemistry and Tissue Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, SP, Brazil.,Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Thalita Rocha
- Department of Biochemistry and Tissue Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, SP, Brazil.,Multidisciplinary Research Laboratory, São Francisco University (USF), Bragança Paulista, SP, Brazil
| | - Evanguedes Kalapothakis
- Department of General Biology, Institute of Biological Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
| | - Maria Alice da Cruz-Höfling
- Department of Biochemistry and Tissue Biology, Institute of Biology, State University of Campinas (UNICAMP), Campinas, SP, Brazil. .,Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, SP, Brazil.
| |
Collapse
|
12
|
Liu WJ, Yang J. Developmental expression of inositol 1, 4, 5-trisphosphate receptor in the post-natal rat cochlea. Eur J Histochem 2015; 59:2486. [PMID: 26150157 PMCID: PMC4503970 DOI: 10.4081/ejh.2015.2486] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 04/06/2015] [Accepted: 04/06/2015] [Indexed: 11/23/2022] Open
Abstract
Inositol 1, 4, 5-trisphosphate receptor (IP3R) has been established to be essential for hearing. However, the expression of IP3R in the cochlea in the period of auditory development remains unknown. We investigated the expression of IP3R in the developing rat cochlea using immunohistochemistry and real-time reverse transcription polymerase chain reaction (RT-PCR). We observed its presence in the developing rat cochlea, and changes in IP3R protein expressions from the early post-natal period to adult. At birth (post-natal day 0, P0), IP3R expression was only found in Hensen's cell. IP3R immunoreactivity first appeared in the sensory hair cells in the organ of Corti at P2. This localization was confirmed by means of double-labeling experiments with Myosin VIIA, a marker for cochlear hair cells. Colocalization of IP3R and Myosin VIIA from P2 to the second post-natal week suggested early expression of IP3R in developing inner and outer hair cells. Claudius' cells near the spiral ligament were labelled for IP3R from P8 onwards. Transient IP3R expression was observed in the stria vascularis in early post-natal rat from P4 to P8. Spiral ganglion neurons also exhibited weaker IP3R fluorescence signals during post-natal development. The results of RT-PCR demonstrated that all three IP3R isoforms (IP3R1, IP3R2, and IP3R3) were present in rat cochlea during four different developmental stages of cochlea, from P0 to P28. Present immunohistochemical evidence for both change and maintenance of expression of IP3R during post-natal development of the rat cochlea indicated the possible involvement of IP3R-mediated calcium signaling in cochlear development.
Collapse
Affiliation(s)
- W J Liu
- Shanghai Jiaotong University.
| | | |
Collapse
|