1
|
Vitureira N, Rafael A, Abudara V. P2X7 receptors and pannexin1 hemichannels shape presynaptic transmission. Purinergic Signal 2024; 20:223-236. [PMID: 37713157 PMCID: PMC11189373 DOI: 10.1007/s11302-023-09965-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 09/06/2023] [Indexed: 09/16/2023] Open
Abstract
Over the last decades, since the discovery of ATP as a transmitter, accumulating evidence has been reported about the role of this nucleotide and purinergic receptors, in particular P2X7 receptors, in the modulation of synaptic strength and plasticity. Purinergic signaling has emerged as a crucial player in orchestrating the molecular interaction between the components of the tripartite synapse, and much progress has been made in how this neuron-glia interaction impacts neuronal physiology under basal and pathological conditions. On the other hand, pannexin1 hemichannels, which are functionally linked to P2X7 receptors, have appeared more recently as important modulators of excitatory synaptic function and plasticity under diverse contexts. In this review, we will discuss the contribution of ATP, P2X7 receptors, and pannexin hemichannels to the modulation of presynaptic strength and its impact on motor function, sensory processing, synaptic plasticity, and neuroglial communication, with special focus on the P2X7 receptor/pannexin hemichannel interplay. We also address major hypotheses about the role of this interaction in physiological and pathological circumstances.
Collapse
Affiliation(s)
- Nathalia Vitureira
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay.
| | - Alberto Rafael
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Verónica Abudara
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay.
| |
Collapse
|
2
|
Guo Z, Yue N, Chen M, Li J, Lv R, Wang J, Liu T, Huang J, Gao S, Li Y, Yuan B, Wang J, Kang L, Ji B, Xin W. Purinergic Receptor Antagonists Inhibit Hemolysis Induced by Clostridium perfringens Alpha Toxin. Pathogens 2024; 13:454. [PMID: 38921752 PMCID: PMC11206506 DOI: 10.3390/pathogens13060454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Revised: 04/28/2024] [Accepted: 05/22/2024] [Indexed: 06/27/2024] Open
Abstract
Clostridium perfringens alpha toxin (CPA), which causes yellow lamb disease in sheep and gas gangrene and food poisoning in humans, is produced by all types of C. perfringens and is the major virulence determinant of C. perfringens type A. CPA induces hemolysis in many species, including humans, murines, sheep and rabbits, through its enzymatic activity, which dissolves the cell membrane. Recent studies have shown that some pore-forming toxins cause hemolysis, which is achieved by the activation of purinergic receptors (P2). However, the relationship between P2 receptors and non-pore-forming toxin hemolysis has not been investigated. In the present study, we examined the function of P2 receptors in CPA toxin hemolysis and found that CPA-induced hemolysis was dependent on P2 receptor activation, and this was also true for Staphylococcus aureus β-Hemolysin, another non-pore-forming toxin. Furthermore, we use selective P2 receptor antagonists to demonstrate that P2X1 and P2X7 play important roles in the hemolysis of human and murine erythrocytes. In addition, we found that redox metabolism was mainly involved in CPA-induced hemolysis using metabolomic analysis. We further demonstrate that CPA activates P2 receptors and then activates NADPH oxidase through the PI3K/Akt and MEK1/ERK1 pathways, followed by the production of active oxygen to induce hemolysis. These findings contribute to our understanding of the pathological effects of CPA, clarify the relationship between P2 activation and non-pore-forming toxin-induced hemolysis, and provide new insights into CPA-induced hemolysis.
Collapse
Affiliation(s)
- Zishuo Guo
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, AMMS, Beijing 100071, China; (Z.G.); (N.Y.); (M.C.); (J.L.); (R.L.); (J.W.); (T.L.); (J.H.); (S.G.); (Y.L.); (B.Y.); (J.W.)
- Emergency Department, 96605 Army Hospital of the People’s Liberation Army, Jilin 134000, China
| | - Nan Yue
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, AMMS, Beijing 100071, China; (Z.G.); (N.Y.); (M.C.); (J.L.); (R.L.); (J.W.); (T.L.); (J.H.); (S.G.); (Y.L.); (B.Y.); (J.W.)
| | - Ming Chen
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, AMMS, Beijing 100071, China; (Z.G.); (N.Y.); (M.C.); (J.L.); (R.L.); (J.W.); (T.L.); (J.H.); (S.G.); (Y.L.); (B.Y.); (J.W.)
| | - Jiaxin Li
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, AMMS, Beijing 100071, China; (Z.G.); (N.Y.); (M.C.); (J.L.); (R.L.); (J.W.); (T.L.); (J.H.); (S.G.); (Y.L.); (B.Y.); (J.W.)
| | - Ruomei Lv
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, AMMS, Beijing 100071, China; (Z.G.); (N.Y.); (M.C.); (J.L.); (R.L.); (J.W.); (T.L.); (J.H.); (S.G.); (Y.L.); (B.Y.); (J.W.)
| | - Jing Wang
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, AMMS, Beijing 100071, China; (Z.G.); (N.Y.); (M.C.); (J.L.); (R.L.); (J.W.); (T.L.); (J.H.); (S.G.); (Y.L.); (B.Y.); (J.W.)
| | - Tingting Liu
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, AMMS, Beijing 100071, China; (Z.G.); (N.Y.); (M.C.); (J.L.); (R.L.); (J.W.); (T.L.); (J.H.); (S.G.); (Y.L.); (B.Y.); (J.W.)
| | - Jing Huang
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, AMMS, Beijing 100071, China; (Z.G.); (N.Y.); (M.C.); (J.L.); (R.L.); (J.W.); (T.L.); (J.H.); (S.G.); (Y.L.); (B.Y.); (J.W.)
| | - Shan Gao
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, AMMS, Beijing 100071, China; (Z.G.); (N.Y.); (M.C.); (J.L.); (R.L.); (J.W.); (T.L.); (J.H.); (S.G.); (Y.L.); (B.Y.); (J.W.)
| | - Yanwei Li
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, AMMS, Beijing 100071, China; (Z.G.); (N.Y.); (M.C.); (J.L.); (R.L.); (J.W.); (T.L.); (J.H.); (S.G.); (Y.L.); (B.Y.); (J.W.)
| | - Bing Yuan
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, AMMS, Beijing 100071, China; (Z.G.); (N.Y.); (M.C.); (J.L.); (R.L.); (J.W.); (T.L.); (J.H.); (S.G.); (Y.L.); (B.Y.); (J.W.)
| | - Jinglin Wang
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, AMMS, Beijing 100071, China; (Z.G.); (N.Y.); (M.C.); (J.L.); (R.L.); (J.W.); (T.L.); (J.H.); (S.G.); (Y.L.); (B.Y.); (J.W.)
| | - Lin Kang
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, AMMS, Beijing 100071, China; (Z.G.); (N.Y.); (M.C.); (J.L.); (R.L.); (J.W.); (T.L.); (J.H.); (S.G.); (Y.L.); (B.Y.); (J.W.)
| | - Bin Ji
- Department of Disease Control, The Affiliated Wuxi Center for Disease Control and Prevention, Nanjing Medical University, Wuxi Center for Disease Control and Prevention, Wuxi 214101, China
| | - Wenwen Xin
- State Key Laboratory of Pathogen and Biosecurity, Institute of Microbiology and Epidemiology, AMMS, Beijing 100071, China; (Z.G.); (N.Y.); (M.C.); (J.L.); (R.L.); (J.W.); (T.L.); (J.H.); (S.G.); (Y.L.); (B.Y.); (J.W.)
| |
Collapse
|
3
|
Rangel-Sandoval C, Soula M, Li WP, Castillo PE, Hunt DL. NMDAR-mediated activation of pannexin1 channels contributes to the detonator properties of hippocampal mossy fiber synapses. iScience 2024; 27:109681. [PMID: 38680664 PMCID: PMC11046245 DOI: 10.1016/j.isci.2024.109681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 02/23/2024] [Accepted: 04/03/2024] [Indexed: 05/01/2024] Open
Abstract
Pannexins are large-pore ion channels expressed throughout the mammalian brain that participate in various neuropathologies; however, their physiological roles remain obscure. Here, we report that pannexin1 channels (Panx1) can be synaptically activated under physiological recording conditions in rodent acute hippocampal slices. Specifically, NMDA receptor (NMDAR)-mediated responses at the mossy fiber to CA3 pyramidal cell synapse were followed by a slow postsynaptic inward current that could activate CA3 pyramidal cells but was absent in Panx1 knockout mice. Immunoelectron microscopy revealed that Panx1 was localized near the postsynaptic density. Further, Panx1-mediated currents were potentiated by metabotropic receptors and bidirectionally modulated by burst-timing-dependent plasticity of NMDAR-mediated transmission. Lastly, Panx1 channels were preferentially recruited when NMDAR activation enters a supralinear regime, resulting in temporally delayed burst-firing. Thus, Panx1 can contribute to synaptic amplification and broadening the temporal associativity window for co-activated pyramidal cells, thereby supporting the auto-associative functions of the CA3 region.
Collapse
Affiliation(s)
- Cinthia Rangel-Sandoval
- Department of Neurosurgery, Department of Neurology, Department of Biomedical Sciences, Center for Neural Science and Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Marisol Soula
- Dominick P. Purpura Department of Neuroscience, Department of Psychiatry and Behavioral Sciences. Albert Einstein College of Medicine, Bronx, NY, USA
| | - Wei-Ping Li
- Howard Hughes Medical Institute, Janelia Research Campus, Ashburn, VA, USA
| | - Pablo E. Castillo
- Dominick P. Purpura Department of Neuroscience, Department of Psychiatry and Behavioral Sciences. Albert Einstein College of Medicine, Bronx, NY, USA
| | - David L. Hunt
- Department of Neurosurgery, Department of Neurology, Department of Biomedical Sciences, Center for Neural Science and Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| |
Collapse
|
4
|
Puebla M, Muñoz MF, Lillo MA, Contreras JE, Figueroa XF. Control of astrocytic Ca 2+ signaling by nitric oxide-dependent S-nitrosylation of Ca 2+ homeostasis modulator 1 channels. Biol Res 2024; 57:19. [PMID: 38689353 PMCID: PMC11059852 DOI: 10.1186/s40659-024-00503-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 04/18/2024] [Indexed: 05/02/2024] Open
Abstract
BACKGROUND Astrocytes Ca2+ signaling play a central role in the modulation of neuronal function. Activation of metabotropic glutamate receptors (mGluR) by glutamate released during an increase in synaptic activity triggers coordinated Ca2+ signals in astrocytes. Importantly, astrocytes express the Ca2+-dependent nitric oxide (NO)-synthetizing enzymes eNOS and nNOS, which might contribute to the Ca2+ signals by triggering Ca2+ influx or ATP release through the activation of connexin 43 (Cx43) hemichannels, pannexin-1 (Panx-1) channels or Ca2+ homeostasis modulator 1 (CALHM1) channels. Hence, we aim to evaluate the participation of NO in the astrocytic Ca2+ signaling initiated by stimulation of mGluR in primary cultures of astrocytes from rat brain cortex. RESULTS Astrocytes were stimulated with glutamate or t-ACPD and NO-dependent changes in [Ca2+]i and ATP release were evaluated. In addition, the activity of Cx43 hemichannels, Panx-1 channels and CALHM1 channels was also analyzed. The expression of Cx43, Panx-1 and CALHM1 in astrocytes was confirmed by immunofluorescence analysis and both glutamate and t-ACPD induced NO-mediated activation of CALHM1 channels via direct S-nitrosylation, which was further confirmed by assessing CALHM1-mediated current using the two-electrode voltage clamp technique in Xenopus oocytes. Pharmacological blockade or siRNA-mediated inhibition of CALHM1 expression revealed that the opening of these channels provides a pathway for ATP release and the subsequent purinergic receptor-dependent activation of Cx43 hemichannels and Panx-1 channels, which further contributes to the astrocytic Ca2+ signaling. CONCLUSIONS Our findings demonstrate that activation of CALHM1 channels through NO-mediated S-nitrosylation in astrocytes in vitro is critical for the generation of glutamate-initiated astrocytic Ca2+ signaling.
Collapse
Affiliation(s)
- Mariela Puebla
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, 8330025, Santiago, Chile
| | - Manuel F Muñoz
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, 8330025, Santiago, Chile
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, USA
| | - Mauricio A Lillo
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, Newark, NJ, USA
| | - Jorge E Contreras
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, USA
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, Newark, NJ, USA
| | - Xavier F Figueroa
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, 8330025, Santiago, Chile.
| |
Collapse
|
5
|
Lucero CM, Navarro L, Barros-Osorio C, Cáceres-Conejeros P, Orellana JA, Gómez GI. Activation of Pannexin-1 channels causes cell dysfunction and damage in mesangial cells derived from angiotensin II-exposed mice. Front Cell Dev Biol 2024; 12:1387234. [PMID: 38660621 PMCID: PMC11041381 DOI: 10.3389/fcell.2024.1387234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2024] [Accepted: 03/25/2024] [Indexed: 04/26/2024] Open
Abstract
Chronic kidney disease (CKD) is a prevalent health concern associated with various pathological conditions, including hypertensive nephropathy. Mesangial cells are crucial in maintaining glomerular function, yet their involvement in CKD pathogenesis remains poorly understood. Recent evidence indicates that overactivation of Pannexin-1 (Panx1) channels could contribute to the pathogenesis and progression of various diseases. Although Panx1 is expressed in the kidney, its contribution to the dysfunction of renal cells during pathological conditions remains to be elucidated. This study aimed to investigate the impact of Panx1 channels on mesangial cell function in the context of hypertensive nephropathy. Using an Ang II-infused mouse model and primary mesangial cell cultures, we demonstrated that in vivo exposure to Ang II sensitizes cultured mesangial cells to show increased alterations when they are subjected to subsequent in vitro exposure to Ang II. Particularly, mesangial cell cultures treated with Ang II showed elevated activity of Panx1 channels and increased release of ATP. The latter was associated with enhanced basal intracellular Ca2+ ([Ca2+]i) and increased ATP-mediated [Ca2+]i responses. These effects were accompanied by increased lipid peroxidation and reduced cell viability. Crucially, all the adverse impacts evoked by Ang II were prevented by the blockade of Panx1 channels, underscoring their critical role in mediating cellular dysfunction in mesangial cells. By elucidating the mechanisms by which Ang II negatively impacts mesangial cell function, this study provides valuable insights into the pathogenesis of renal damage in hypertensive nephropathy.
Collapse
Affiliation(s)
- Claudia M. Lucero
- Institute of Biomedical Sciences, Faculty of Health Sciences, Universidad Autónoma de Chile, Santiago, Chile
| | - Laura Navarro
- Institute of Biomedical Sciences, Faculty of Health Sciences, Universidad Autónoma de Chile, Santiago, Chile
| | - Cristián Barros-Osorio
- Institute of Biomedical Sciences, Faculty of Health Sciences, Universidad Autónoma de Chile, Santiago, Chile
| | - Patricio Cáceres-Conejeros
- Institute of Biomedical Sciences, Faculty of Health Sciences, Universidad Autónoma de Chile, Santiago, Chile
| | - Juan A. Orellana
- Departamento de Neurología, Escuela de Medicina and Centro Interdisciplinario de Neurociencias, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Gonzalo I. Gómez
- Institute of Biomedical Sciences, Faculty of Health Sciences, Universidad Autónoma de Chile, Santiago, Chile
| |
Collapse
|
6
|
Fish A, Kulkarni A. Flow-Induced Shear Stress Primes NLRP3 Inflammasome Activation in Macrophages via Piezo1. ACS APPLIED MATERIALS & INTERFACES 2024; 16:4505-4518. [PMID: 38240257 DOI: 10.1021/acsami.3c18645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
The NLRP3 inflammasome is a crucial component of the innate immune system, playing a pivotal role in initiating and regulating the body's inflammatory response to various pathogens and cellular damage. Environmental stimuli, such as temperature, pH level, and nutrient availability, can influence the behavior and functions of innate immune cells, including immune cell activity, proliferation, and cytokine production. However, there is limited understanding regarding how mechanical forces, like shear stress, govern the intrinsic inflammatory reaction, particularly the activation of the NLRP3 inflammasome, and how shear stress impacts NLRP3 inflammasome activation through its capacity to induce alterations in gene expression and cytokine secretion. Here, we investigated how shear stress can act as a priming signal in NLRP3 inflammasome activation by exposing immortalized bone marrow-derived macrophages (iBMDMs) to numerous physiologically relevant magnitudes of shear stress before chemically inducing inflammasome activation. We demonstrated that shear stress of large magnitudes was able to prime iBMDMs more effectively for inflammasome activation compared to lower shear stress magnitudes, as quantified by the percentage of cells where ASC-CFP specks formed and IL-1β secretion, the hallmarks of inflammasome activation. Testing this in NLRP3 and caspase-1 knockout iBMDMs showed that the NLRP3 inflammasome was primarily primed for activation due to shear stress exposure. Quantitative polymerase chain reaction (qPCR) and a small-molecule inhibitor study mechanistically determined that shear stress regulates the NLRP3 inflammasome by upregulating Piezo1, IKKβ, and NLRP3. These findings offer insights into the mechanistic relationship among physiological shear stresses, inflammasome activation, and their impact on the progression of inflammatory diseases and their interconnected pathogenesis.
Collapse
Affiliation(s)
- Adam Fish
- Department of Chemical Engineering, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - Ashish Kulkarni
- Department of Chemical Engineering, University of Massachusetts, Amherst, Massachusetts 01003, United States
- Center for Bioactive Delivery, Institute for Applied Life Sciences, University of Massachusetts, Amherst, Massachusetts 01003, United States
| |
Collapse
|
7
|
Fukuyama K, Motomura E, Okada M. Age-Dependent Activation of Pannexin1 Function Contributes to the Development of Epileptogenesis in Autosomal Dominant Sleep-related Hypermotor Epilepsy Model Rats. Int J Mol Sci 2024; 25:1619. [PMID: 38338895 PMCID: PMC10855882 DOI: 10.3390/ijms25031619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 01/23/2024] [Accepted: 01/25/2024] [Indexed: 02/12/2024] Open
Abstract
To explore the processes of epileptogenesis/ictogenesis, this study determined the age-dependent development of the functional abnormalities in astroglial transmission associated with pannexin1-hemichannel using a genetic rat model of autosomal dominant sleep-related hypermotor epilepsy (ADSHE) named 'S286L-TG'. Pannexin1 expression in the plasma membrane of primary cultured cortical astrocytes and the orbitofrontal cortex (OFC), which is an ADSHE focus region, were determined using capillary immunoblotting. Astroglial D-serine releases induced by artificial high-frequency oscillation (HFO)-evoked stimulation, the removal of extracellular Ca2+, and the P2X7 receptor agonist (BzATP) were determined using ultra-high performance liquid chromatography (UHPLC). The expressions of pannexin1 in the plasma membrane fraction of the OFC in S286L-TG at four weeks old were almost equivalent when compared to the wild type. The pannexin1 expression in the OFC of the wild type non-statistically decreased age-dependently, whereas that in S286L-TG significantly increased age-dependently, resulting in relatively increasing pannexin1 expression from the 7- (at the onset of interictal discharge) and 10-week-old (after the ADSHE seizure onset) S286L-TG compared to the wild type. However, no functional abnormalities of astroglial pannexin1 expression or D-serine release through the pannexin1-hemichannels from the cultured astrocytes of S286L-TG could be detected. Acutely HFO-evoked stimulation, such as physiological ripple burst (200 Hz) and epileptogenic fast ripple burst (500 Hz), frequency-dependently increased both pannexin1 expression in the astroglial plasma membrane and astroglial D-serine release. Neither the selective inhibitors of pannexin1-hemichannel (10PANX) nor connexin43-hemichannel (Gap19) affected astroglial D-serine release during the resting stage, whereas HFO-evoked D-serine release was suppressed by both inhibitors. The inhibitory effect of 10PANX on the ripple burst-evoked D-serine release was more predominant than that of Gap19, whereas fast ripple burst-evoked D-serine release was predominantly suppressed by Gap19 rather than 10PANX. Astroglial D-serine release induced by acute exposure to BzATP was suppressed by 10PANX but not by Gap19. These results suggest that physiological ripple burst during the sleep spindle plays important roles in the organization of some components of cognition in healthy individuals, but conversely, it contributes to the initial development of epileptogenesis/ictogenesis in individuals who have ADSHE vulnerability via activation of the astroglial excitatory transmission associated with pannexin1-hemichannels.
Collapse
Affiliation(s)
| | | | - Motohiro Okada
- Department of Neuropsychiatry, Division of Neuroscience, Graduate School of Medicine, Mie University, Tsu 514-8507, Japan; (K.F.); (E.M.)
| |
Collapse
|
8
|
Alarcon-Martinez L, Shiga Y, Villafranca-Baughman D, Cueva Vargas JL, Vidal Paredes IA, Quintero H, Fortune B, Danesh-Meyer H, Di Polo A. Neurovascular dysfunction in glaucoma. Prog Retin Eye Res 2023; 97:101217. [PMID: 37778617 DOI: 10.1016/j.preteyeres.2023.101217] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 09/23/2023] [Accepted: 09/25/2023] [Indexed: 10/03/2023]
Abstract
Retinal ganglion cells, the neurons that die in glaucoma, are endowed with a high metabolism requiring optimal provision of oxygen and nutrients to sustain their activity. The timely regulation of blood flow is, therefore, essential to supply firing neurons in active areas with the oxygen and glucose they need for energy. Many glaucoma patients suffer from vascular deficits including reduced blood flow, impaired autoregulation, neurovascular coupling dysfunction, and blood-retina/brain-barrier breakdown. These processes are tightly regulated by a community of cells known as the neurovascular unit comprising neurons, endothelial cells, pericytes, Müller cells, astrocytes, and microglia. In this review, the neurovascular unit takes center stage as we examine the ability of its members to regulate neurovascular interactions and how their function might be altered during glaucomatous stress. Pericytes receive special attention based on recent data demonstrating their key role in the regulation of neurovascular coupling in physiological and pathological conditions. Of particular interest is the discovery and characterization of tunneling nanotubes, thin actin-based conduits that connect distal pericytes, which play essential roles in the complex spatial and temporal distribution of blood within the retinal capillary network. We discuss cellular and molecular mechanisms of neurovascular interactions and their pathophysiological implications, while highlighting opportunities to develop strategies for vascular protection and regeneration to improve functional outcomes in glaucoma.
Collapse
Affiliation(s)
- Luis Alarcon-Martinez
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada; Centre for Eye Research Australia, University of Melbourne, Melbourne, Australia
| | - Yukihiro Shiga
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada
| | - Deborah Villafranca-Baughman
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada
| | - Jorge L Cueva Vargas
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada
| | - Isaac A Vidal Paredes
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada
| | - Heberto Quintero
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada
| | - Brad Fortune
- Discoveries in Sight Research Laboratories, Devers Eye Institute and Legacy Research Institute, Legacy Healthy, Portland, OR, USA
| | - Helen Danesh-Meyer
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, New Zealand
| | - Adriana Di Polo
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada.
| |
Collapse
|
9
|
Akula SK, Chen AY, Neil JE, Shao DD, Mo A, Hylton NK, DiTroia S, Ganesh VS, Smith RS, O’Kane K, Yeh RC, Marciano JH, Kirkham S, Kenny CJ, Song JHT, Al Saffar M, Millan F, Harris DJ, Murphy AV, Klemp KC, Braddock SR, Brand H, Wong I, Talkowski ME, O’Donnell-Luria A, Lai A, Hill RS, Mochida GH, Doan RN, Barkovich AJ, Yang E, Amrom D, Andermann E, Poduri A, Walsh CA. Exome Sequencing and the Identification of New Genes and Shared Mechanisms in Polymicrogyria. JAMA Neurol 2023; 80:980-988. [PMID: 37486637 PMCID: PMC10366952 DOI: 10.1001/jamaneurol.2023.2363] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 03/23/2023] [Indexed: 07/25/2023]
Abstract
Importance Polymicrogyria is the most commonly diagnosed cortical malformation and is associated with neurodevelopmental sequelae including epilepsy, motor abnormalities, and cognitive deficits. Polymicrogyria frequently co-occurs with other brain malformations or as part of syndromic diseases. Past studies of polymicrogyria have defined heterogeneous genetic and nongenetic causes but have explained only a small fraction of cases. Objective To survey germline genetic causes of polymicrogyria in a large cohort and to consider novel polymicrogyria gene associations. Design, Setting, and Participants This genetic association study analyzed panel sequencing and exome sequencing of accrued DNA samples from a retrospective cohort of families with members with polymicrogyria. Samples were accrued over more than 20 years (1994 to 2020), and sequencing occurred in 2 stages: panel sequencing (June 2015 to January 2016) and whole-exome sequencing (September 2019 to March 2020). Individuals seen at multiple clinical sites for neurological complaints found to have polymicrogyria on neuroimaging, then referred to the research team by evaluating clinicians, were included in the study. Targeted next-generation sequencing and/or exome sequencing were performed on probands (and available parents and siblings) from 284 families with individuals who had isolated polymicrogyria or polymicrogyria as part of a clinical syndrome and no genetic diagnosis at time of referral from clinic, with sequencing from 275 families passing quality control. Main Outcomes and Measures The number of families in whom genetic sequencing yielded a molecular diagnosis that explained the polymicrogyria in the family. Secondarily, the relative frequency of different genetic causes of polymicrogyria and whether specific genetic causes were associated with co-occurring head size changes were also analyzed. Results In 32.7% (90 of 275) of polymicrogyria-affected families, genetic variants were identified that provided satisfactory molecular explanations. Known genes most frequently implicated by polymicrogyria-associated variants in this cohort were PIK3R2, TUBB2B, COL4A1, and SCN3A. Six candidate novel polymicrogyria genes were identified or confirmed: de novo missense variants in PANX1, QRICH1, and SCN2A and compound heterozygous variants in TMEM161B, KIF26A, and MAN2C1, each with consistent genotype-phenotype relationships in multiple families. Conclusions and Relevance This study's findings reveal a higher than previously recognized rate of identifiable genetic causes, specifically of channelopathies, in individuals with polymicrogyria and support the utility of exome sequencing for families affected with polymicrogyria.
Collapse
Affiliation(s)
- Shyam K. Akula
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children’s Hospital, and Allen Discovery Center for Human Brain Evolution, Boston, Massachusetts
- Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, Massachusetts
- Harvard-MIT MD/PhD Program, Harvard Medical School, Boston, Massachusetts
| | - Allen Y. Chen
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children’s Hospital, and Allen Discovery Center for Human Brain Evolution, Boston, Massachusetts
- Division of Rheumatology, Hospital for Special Surgery, New York, New York
| | - Jennifer E. Neil
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children’s Hospital, and Allen Discovery Center for Human Brain Evolution, Boston, Massachusetts
- Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, Massachusetts
| | - Diane D. Shao
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children’s Hospital, and Allen Discovery Center for Human Brain Evolution, Boston, Massachusetts
- Department of Neurology, Boston Children’s Hospital, Boston, Massachusetts
- Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, Massachusetts
| | - Alisa Mo
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children’s Hospital, and Allen Discovery Center for Human Brain Evolution, Boston, Massachusetts
- Department of Neurology, Boston Children’s Hospital, Boston, Massachusetts
- Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, Massachusetts
| | - Norma K. Hylton
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children’s Hospital, and Allen Discovery Center for Human Brain Evolution, Boston, Massachusetts
- Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, Massachusetts
- Harvard-MIT MD/PhD Program, Harvard Medical School, Boston, Massachusetts
| | - Stephanie DiTroia
- Program in Medical and Population Genetics, Center for Genomic Medicine, Stanley Center for Psychiatric Research, The Broad Institute of MIT and Harvard, Cambridge, Massachusetts
| | - Vijay S. Ganesh
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children’s Hospital, and Allen Discovery Center for Human Brain Evolution, Boston, Massachusetts
- Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, Massachusetts
| | - Richard S. Smith
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Katherine O’Kane
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children’s Hospital, and Allen Discovery Center for Human Brain Evolution, Boston, Massachusetts
- Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, Massachusetts
| | - Rebecca C. Yeh
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children’s Hospital, and Allen Discovery Center for Human Brain Evolution, Boston, Massachusetts
- Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, Massachusetts
| | - Jack H. Marciano
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children’s Hospital, and Allen Discovery Center for Human Brain Evolution, Boston, Massachusetts
- Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, Massachusetts
| | - Samantha Kirkham
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children’s Hospital, and Allen Discovery Center for Human Brain Evolution, Boston, Massachusetts
- Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, Massachusetts
| | - Connor J. Kenny
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children’s Hospital, and Allen Discovery Center for Human Brain Evolution, Boston, Massachusetts
- Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, Massachusetts
| | - Janet H. T. Song
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children’s Hospital, and Allen Discovery Center for Human Brain Evolution, Boston, Massachusetts
- Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, Massachusetts
| | - Muna Al Saffar
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children’s Hospital, and Allen Discovery Center for Human Brain Evolution, Boston, Massachusetts
- Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, Massachusetts
- Department of Genetics and Genomics, United Arab Emirates University, United Arab Emirates
| | | | - David J. Harris
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children’s Hospital, and Allen Discovery Center for Human Brain Evolution, Boston, Massachusetts
- Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, Massachusetts
| | - Andrea V. Murphy
- Division of Medical Genetics, Our Lady of the Lake Health System, Baton Rouge, Louisiana
| | - Kara C. Klemp
- Division of Medical Genetics, Department of Pediatrics Saint Louis University School of Medicine, St Louis, Missouri
| | - Stephen R. Braddock
- Division of Medical Genetics, Department of Pediatrics Saint Louis University School of Medicine, St Louis, Missouri
| | - Harrison Brand
- Program in Medical and Population Genetics, Center for Genomic Medicine, Stanley Center for Psychiatric Research, The Broad Institute of MIT and Harvard, Cambridge, Massachusetts
- Department of Neurology, Harvard Medical School, Boston, Massachusetts
| | - Isaac Wong
- Program in Medical and Population Genetics, Center for Genomic Medicine, Stanley Center for Psychiatric Research, The Broad Institute of MIT and Harvard, Cambridge, Massachusetts
- Department of Neurology, Harvard Medical School, Boston, Massachusetts
| | - Michael E. Talkowski
- Program in Medical and Population Genetics, Center for Genomic Medicine, Stanley Center for Psychiatric Research, The Broad Institute of MIT and Harvard, Cambridge, Massachusetts
- Department of Neurology, Harvard Medical School, Boston, Massachusetts
| | - Anne O’Donnell-Luria
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children’s Hospital, and Allen Discovery Center for Human Brain Evolution, Boston, Massachusetts
- Program in Medical and Population Genetics, Center for Genomic Medicine, Stanley Center for Psychiatric Research, The Broad Institute of MIT and Harvard, Cambridge, Massachusetts
| | - Abbe Lai
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children’s Hospital, and Allen Discovery Center for Human Brain Evolution, Boston, Massachusetts
- Department of Neurology, Boston Children’s Hospital, Boston, Massachusetts
| | - Robert Sean Hill
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children’s Hospital, and Allen Discovery Center for Human Brain Evolution, Boston, Massachusetts
- Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, Massachusetts
| | - Ganeshwaran H. Mochida
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children’s Hospital, and Allen Discovery Center for Human Brain Evolution, Boston, Massachusetts
- Department of Neurology, Boston Children’s Hospital, Boston, Massachusetts
- Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, Massachusetts
| | - Ryan N. Doan
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children’s Hospital, and Allen Discovery Center for Human Brain Evolution, Boston, Massachusetts
| | - A. James Barkovich
- Benioff Children’s Hospital, Departments of Radiology, Pediatrics, Neurology, and Neurological Surgery, University of California, San Francisco, San Francisco
| | - Edward Yang
- Department of Radiology, Boston Children’s Hospital, Boston, Massachusetts
| | - Dina Amrom
- Neurogenetics Unit, Montreal Neurological Hospital and Institute, Montreal, Quebec, Canada
- Department of Neurology & Neurosurgery, McGill University, Montreal, Quebec, Canada
- Department of Neurology, Queen Fabiola Children’s University Hospital, Brussels, Belgium
- Pediatric Neurology Unit, Centre Hospitalier de Luxembourg, Grand-Duchy of Luxembourg
| | - Eva Andermann
- Department of Neurology & Neurosurgery, McGill University, Montreal, Quebec, Canada
- Pediatric Neurology Unit, Centre Hospitalier de Luxembourg, Grand-Duchy of Luxembourg
- Epilepsy Research Group, Montreal Neurological Hospital and Institute, Quebec, Canada
- Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Annapurna Poduri
- Department of Neurology, Boston Children’s Hospital, Boston, Massachusetts
| | - Christopher A. Walsh
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children’s Hospital, and Allen Discovery Center for Human Brain Evolution, Boston, Massachusetts
- Howard Hughes Medical Institute, Boston Children’s Hospital, Boston, Massachusetts
- Harvard-MIT MD/PhD Program, Harvard Medical School, Boston, Massachusetts
- Program in Medical and Population Genetics, Center for Genomic Medicine, Stanley Center for Psychiatric Research, The Broad Institute of MIT and Harvard, Cambridge, Massachusetts
| |
Collapse
|
10
|
Understanding the Role of ATP Release through Connexins Hemichannels during Neurulation. Int J Mol Sci 2023; 24:ijms24032159. [PMID: 36768481 PMCID: PMC9916920 DOI: 10.3390/ijms24032159] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/30/2022] [Accepted: 01/04/2023] [Indexed: 01/25/2023] Open
Abstract
Neurulation is a crucial process in the formation of the central nervous system (CNS), which begins with the folding and fusion of the neural plate, leading to the generation of the neural tube and subsequent development of the brain and spinal cord. Environmental and genetic factors that interfere with the neurulation process promote neural tube defects (NTDs). Connexins (Cxs) are transmembrane proteins that form gap junctions (GJs) and hemichannels (HCs) in vertebrates, allowing cell-cell (GJ) or paracrine (HCs) communication through the release of ATP, glutamate, and NAD+; regulating processes such as cell migration and synaptic transmission. Changes in the state of phosphorylation and/or the intracellular redox potential activate the opening of HCs in different cell types. Cxs such as Cx43 and Cx32 have been associated with proliferation and migration at different stages of CNS development. Here, using molecular and cellular biology techniques (permeability), we demonstrate the expression and functionality of HCs-Cxs, including Cx46 and Cx32, which are associated with the release of ATP during the neurulation process in Xenopus laevis. Furthermore, applications of FGF2 and/or changes in intracellular redox potentials (DTT), well known HCs-Cxs modulators, transiently regulated the ATP release in our model. Importantly, the blockade of HCs-Cxs by carbenoxolone (CBX) and enoxolone (ENX) reduced ATP release with a concomitant formation of NTDs. We propose two possible and highly conserved binding sites (N and E) in Cx46 that may mediate the pharmacological effect of CBX and ENX on the formation of NTDs. In summary, our results highlight the importance of ATP release mediated by HCs-Cxs during neurulation.
Collapse
|
11
|
Barrachina F, Ottino K, Tu LJ, Soberman RJ, Brown D, Breton S, Battistone MA. CX3CR1 deficiency leads to impairment of immune surveillance in the epididymis. Cell Mol Life Sci 2022; 80:15. [PMID: 36550225 PMCID: PMC9948740 DOI: 10.1007/s00018-022-04664-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 11/09/2022] [Accepted: 12/09/2022] [Indexed: 12/24/2022]
Abstract
Mononuclear phagocytes (MPs) play an active role in the immunological homeostasis of the urogenital tract. In the epididymis, a finely tuned balance between tolerance to antigenic sperm and immune activation is required to maintain epididymal function while protecting sperm against pathogens and stressors. We previously characterized a subset of resident MPs that express the CX3CR1 receptor, emphasizing their role in antigen sampling and processing during sperm maturation and storage in the murine epididymis. Bacteria-associated epididymitis is the most common cause of intrascrotal inflammation and frequently leads to reproductive complications. Here, we examined whether the lack of functional CX3CR1 in homozygous mice (CX3CR1EGFP/EGFP, KO) alters the ability of MPs to initiate immune responses during epididymitis induced by LPS intravasal-epididymal injection. Confocal microscopy revealed that CX3CR1-deficient MPs located in the initial segments of the epididymis displayed fewer luminal-reaching membrane projections and impaired antigen capture activity. Moreover, flow cytometry showed a reduction of epididymal KO MPs with a monocytic phenotype under physiological conditions. In contrast, flow cytometry revealed an increase in the abundance of MPs with a monocytic signature in the distal epididymal segments after an LPS challenge. This was accompanied by the accumulation of CD103+ cells in the interstitium, and the prevention or attenuation of epithelial damage in the KO epididymis during epididymitis. Additionally, CX3CR1 deletion induced downregulation of Gja1 (connexin 43) expression in KO MPs. Together, our study provides evidence that MPs are gatekeepers of the immunological blood-epididymis barrier and reveal the role of the CX3CR1 receptor in epididymal mucosal homeostasis by inducing MP luminal protrusions and by regulating the monocyte population in the epididymis at steady state as well as upon infection. We also uncover the interaction between MPs and CD103+ dendritic cells, presumably through connexin 43, that enhance immune responses during epididymitis. Our study may lead to new diagnostics and therapies for male infertility and epididymitis by identifying immune mechanisms in the epididymis.
Collapse
Affiliation(s)
- F Barrachina
- Program in Membrane Biology, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
- Nephrology Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - K Ottino
- Program in Membrane Biology, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
- Nephrology Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - L J Tu
- Program in Membrane Biology, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
- Nephrology Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - R J Soberman
- Nephrology Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - D Brown
- Program in Membrane Biology, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
- Nephrology Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - S Breton
- Centre Hospitalier Universitaire de Québec-Research Center, Department of Obstetrics, Gynecology, and Reproduction, Faculty of Medicine, Université Laval, Québec, QC, Canada
| | - M A Battistone
- Program in Membrane Biology, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA.
- Nephrology Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA.
| |
Collapse
|
12
|
Hypertensive Nephropathy: Unveiling the Possible Involvement of Hemichannels and Pannexons. Int J Mol Sci 2022; 23:ijms232415936. [PMID: 36555574 PMCID: PMC9785367 DOI: 10.3390/ijms232415936] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 12/09/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022] Open
Abstract
Hypertension is one of the most common risk factors for developing chronic cardiovascular diseases, including hypertensive nephropathy. Within the glomerulus, hypertension causes damage and activation of mesangial cells (MCs), eliciting the production of large amounts of vasoactive and proinflammatory agents. Accordingly, the activation of AT1 receptors by the vasoactive molecule angiotensin II (AngII) contributes to the pathogenesis of renal damage, which is mediated mostly by the dysfunction of intracellular Ca2+ ([Ca2+]i) signaling. Similarly, inflammation entails complex processes, where [Ca2+]i also play crucial roles. Deregulation of this second messenger increases cell damage and promotes fibrosis, reduces renal blood flow, and impairs the glomerular filtration barrier. In vertebrates, [Ca2+]i signaling depends, in part, on the activity of two families of large-pore channels: hemichannels and pannexons. Interestingly, the opening of these channels depends on [Ca2+]i signaling. In this review, we propose that the opening of channels formed by connexins and/or pannexins mediated by AngII induces the ATP release to the extracellular media, with the subsequent activation of purinergic receptors. This process could elicit Ca2+ overload and constitute a feed-forward mechanism, leading to kidney damage.
Collapse
|
13
|
Alberto AVP, Ferreira NCDS, Bonavita AGC, Nihei OK, de Farias FP, Bisaggio RDC, de Albuquerque C, Savino W, Coutinho‐Silva R, Persechini PM, Alves LA. Physiologic roles of P2 receptors in leukocytes. J Leukoc Biol 2022; 112:983-1012. [PMID: 35837975 PMCID: PMC9796137 DOI: 10.1002/jlb.2ru0421-226rr] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 06/13/2022] [Indexed: 01/01/2023] Open
Abstract
Since their discovery in the 1970s, purinergic receptors have been shown to play key roles in a wide variety of biologic systems and cell types. In the immune system, purinergic receptors participate in innate immunity and in the modulation of the adaptive immune response. In particular, P2 receptors, which respond to extracellular nucleotides, are widely expressed on leukocytes, causing the release of cytokines and chemokines and the formation of inflammatory mediators, and inducing phagocytosis, degranulation, and cell death. The activity of these receptors is regulated by ectonucleotidases-expressed in these same cell types-which regulate the availability of nucleotides in the extracellular environment. In this article, we review the characteristics of the main purinergic receptor subtypes present in the immune system, focusing on the P2 family. In addition, we describe the physiologic roles of the P2 receptors already identified in leukocytes and how they can positively or negatively modulate the development of infectious diseases, inflammation, and pain.
Collapse
Affiliation(s)
- Anael Viana Pinto Alberto
- Laboratory of Cellular Communication, Oswaldo Cruz InstituteOswaldo Cruz FoundationRio de JaneiroRJBrazil
| | | | | | - Oscar Kenji Nihei
- Center of Education and LetterState University of the West of ParanáFoz do IguaçuPRBrazil
| | | | - Rodrigo da Cunha Bisaggio
- Laboratory of Cellular Communication, Oswaldo Cruz InstituteOswaldo Cruz FoundationRio de JaneiroRJBrazil,Federal Institute of Education, Science, and Technology of Rio de JaneiroRio de JaneiroRJBrazil
| | | | - Wilson Savino
- Laboratory on Thymus Research, Oswaldo Cruz InstituteOswaldo Cruz FoundationRio de JaneiroRJBrazil,Brazilian National Institute of Science and Technology on NeuroimmunomodulationRio de Janeiro Research Network on NeuroinflammationRio de JaneiroRJBrazil
| | - Robson Coutinho‐Silva
- Laboratory of Immunophysiology, Carlos Chagas Filho Biophysics InstituteFederal University of Rio de JaneiroRio de JaneiroRJBrazil
| | - Pedro Muanis Persechini
- Laboratory of Immunobiophysics, Carlos Chagas Filho Biophysics InstituteFederal University of Rio de JaneiroRio de JaneiroRJBrazil
| | - Luiz Anastacio Alves
- Laboratory of Cellular Communication, Oswaldo Cruz InstituteOswaldo Cruz FoundationRio de JaneiroRJBrazil
| |
Collapse
|
14
|
Meter D, Racetin A, Vukojević K, Balog M, Ivić V, Zjalić M, Heffer M, Filipović N. A Lack of GD3 Synthase Leads to Impaired Renal Expression of Connexins and Pannexin1 in St8sia1 Knockout Mice. Int J Mol Sci 2022; 23:ijms23116237. [PMID: 35682927 PMCID: PMC9181035 DOI: 10.3390/ijms23116237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Revised: 05/28/2022] [Accepted: 05/30/2022] [Indexed: 02/01/2023] Open
Abstract
The aim of this study was to determine the effects of altered ganglioside composition on the expression of Cx37, Cx40, Cx43, Cx45, and Panx1 in different kidney regions of St8sia1 gene knockout mice (St8sia1 KO) lacking the GD3 synthase enzyme. Experiments were performed in twelve male 6-month-old mice: four wild-type (C57BL/6-type, WT) and eight St8sia1 KO mice. After euthanasia, kidney tissue was harvested, embedded in paraffin wax, and processed for immunohistochemistry. The expression of connexins and Panx1 was determined in different regions of the kidney: cortex (CTX.), outer stripe of outer medulla (O.S.), inner stripe of outer medulla (IN.S.), and inner medulla (IN.MED.). We determined significantly lower expression of Cx37, Cx40, Cx45, and Panx1 in different parts of the kidneys of St8sia1 KO mice compared with WT. The most consistent decrease was found in the O.S. where all markers (Cx 37, 40, 45 and Panx1) were disrupted in St8si1 KO mice. In the CTX. region, we observed decrease in the expression of Cx37, Cx45, and Panx1, while reduced expression of Cx37 and Panx1 was more specific to IN.S. The results of the present study suggest that deficiency of GD3 synthase in St8sia1 KO mice leads to disruption of renal Cx expression, which is probably related to alteration of ganglioside composition.
Collapse
Affiliation(s)
- Diana Meter
- Department of Rheumatology and Clinical Immunology, University Hospital of Split, Spinčićeva 1, 21000 Split, Croatia;
| | - Anita Racetin
- Laboratory for Early Human Development, Department of Anatomy, Histology and Embryology, University of Split School of Medicine, Šoltanska 2, 21000 Split, Croatia; (A.R.); (K.V.)
| | - Katarina Vukojević
- Laboratory for Early Human Development, Department of Anatomy, Histology and Embryology, University of Split School of Medicine, Šoltanska 2, 21000 Split, Croatia; (A.R.); (K.V.)
- Laboratory for Neurocardiology, Department of Anatomy, Histology and Embryology, University of Split School of Medicine, Šoltanska 2, 21000 Split, Croatia
| | - Marta Balog
- Department of Medical Biology and Genetics, Faculty of Medicine Osijek, Josip Juraj Strossmayer University of Osijek, Huttlerova 4, 31000 Osijek, Croatia; (M.B.); (V.I.); (M.H.)
| | - Vedrana Ivić
- Department of Medical Biology and Genetics, Faculty of Medicine Osijek, Josip Juraj Strossmayer University of Osijek, Huttlerova 4, 31000 Osijek, Croatia; (M.B.); (V.I.); (M.H.)
| | - Milorad Zjalić
- Department of Molecular Medicine and Biotechnology, Faculty of Medicine Rijeka, University of Rijeka, Branchetta brothers 20, 51000 Rijeka, Croatia;
| | - Marija Heffer
- Department of Medical Biology and Genetics, Faculty of Medicine Osijek, Josip Juraj Strossmayer University of Osijek, Huttlerova 4, 31000 Osijek, Croatia; (M.B.); (V.I.); (M.H.)
| | - Natalija Filipović
- Laboratory for Early Human Development, Department of Anatomy, Histology and Embryology, University of Split School of Medicine, Šoltanska 2, 21000 Split, Croatia; (A.R.); (K.V.)
- Correspondence:
| |
Collapse
|
15
|
Pannexin-1 Activation by Phosphorylation Is Crucial for Platelet Aggregation and Thrombus Formation. Int J Mol Sci 2022; 23:ijms23095059. [PMID: 35563450 PMCID: PMC9100471 DOI: 10.3390/ijms23095059] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 04/27/2022] [Accepted: 04/29/2022] [Indexed: 02/04/2023] Open
Abstract
Pannexin-1 (PANX1) is a transmembrane protein that forms ion channels as hexamers on the plasma membrane. Electrophysiological studies prove that PANX1 has a high conductance for adenosine triphosphate (ATP), which plays an important role as a signal molecule in platelet activation. Recently, it was shown that PANX1 channels modulate platelet functions. To date, it remains unclear how PANX1 channels are activated and which signaling mechanisms are responsible for impaired hemostasis and thrombosis. Analysis of PANX1 phosphorylation at Tyr198 and Tyr308, and the impact on platelet activation and thrombus formation using genetically modified platelets or pharmacological inhibitors. Platelet activation via immunoreceptor tyrosine-based activation motif (ITAM) coupled, G Protein-Coupled Receptors (GPCR) and thromboxane receptor (TP)-mediated signaling pathways led to increased PANX1 phosphorylation at Tyr198 and Tyr308. We identified the Src-GPVI signaling axes as the main pathway inducing PANX1 activation, while PKC and Akt play a minor role. PANX1 channels function as ATP release channels in platelets to support arterial thrombus formation. PANX1 activation is regulated by phosphorylation at Tyr198 and Tyr308 following platelet activation. These results suggest an important role of PANX1 in hemostasis and thrombosis by releasing extracellular ATP to support thrombus formation.
Collapse
|
16
|
Expression of Pannexin 1 in the Human Kidney during Embryonal, Early Fetal and Postnatal Development and Its Prognostic Significance in Diabetic Nephropathy. Biomedicines 2022; 10:biomedicines10050944. [PMID: 35625681 PMCID: PMC9139113 DOI: 10.3390/biomedicines10050944] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 03/31/2022] [Accepted: 04/19/2022] [Indexed: 02/01/2023] Open
Abstract
Pannexins are transmembrane glycoproteins that constitute channels involved in purinergic signaling through ATP release from cells in various physiological and pathological processes. In this study, the distribution of Panx1 expression in different cell populations of healthy postnatal human kidneys and during human embryonic and early fetal development was investigated by double immunohistochemistry. In addition, the glomerular and tubular expression of Panx1 was examined in patients with type 2 diabetes mellitus (DM2) and the control group, and renal Panx1 expression was correlated with serum creatinine. In the 6th week of embryonic development (DW), Panx1 expression was found in mesonephric glomeruli and mesonephric tubules. At the transition from 6th to 7th DW, Panx1 immunoreactivity was found in the mesonephric tubules and mesonephric duct, as well as in the metanephric ureteric bud and ampullae. In the 7th DW, strong Panx1 immunoreactivity was observed in the developing ureteric bud in the metanephros, whereas no Panx1 immunoreactivity was found in the metanephric cup. In the 8th DW, Panx1 expression was also found in the ureteric bud of the metanephros, the renal vesicle and comma-shaped nephron, and the epithelial cells of Bowman’s capsule. Expression of Panx1 was found at an early stage in both the paramesonephric duct and the mesonephric duct and diminished toward the 8th DW. During the 6th–10th DW, colocalization of Panx1 with alpha smooth actin (aSMA) was found in developing blood vessels. In the postnatal kidney, strong Panx1 immunoreactivity was present in medullary and cortical collecting duct cells, renin-producing cells, and proximal tubules. Very weak Panx1 immunoreactivity was found in certain distal tubule cells and the thin descending limbs of the loop of Henle. Panx1 immunoreactivity was also found in nephrin-immunoreactive podocytes. Panx1 was not colocalized with aSMA immunoreactivity in the vessels of the postnatal human kidney, but it was present in the endothelium. A significant positive correlation was found between Panx1 expression in glomeruli and serum creatinine only in diabetic patients and was not found in the nondiabetic group. The spatiotemporal expression of Panx1 during the early stages of human kidney development supports its possible role in cellular differentiation, migration, and positioning in the developing human kidney. In addition, our data suggest that glomerular Panx1 expression is a potential indicator of worsening renal function in patients with type 2 diabetes.
Collapse
|
17
|
Dunton AD, Göpel T, Ho DH, Burggren W. Form and Function of the Vertebrate and Invertebrate Blood-Brain Barriers. Int J Mol Sci 2021; 22:ijms222212111. [PMID: 34829989 PMCID: PMC8618301 DOI: 10.3390/ijms222212111] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 10/23/2021] [Accepted: 10/28/2021] [Indexed: 12/25/2022] Open
Abstract
The need to protect neural tissue from toxins or other substances is as old as neural tissue itself. Early recognition of this need has led to more than a century of investigation of the blood-brain barrier (BBB). Many aspects of this important neuroprotective barrier have now been well established, including its cellular architecture and barrier and transport functions. Unsurprisingly, most research has had a human orientation, using mammalian and other animal models to develop translational research findings. However, cell layers forming a barrier between vascular spaces and neural tissues are found broadly throughout the invertebrates as well as in all vertebrates. Unfortunately, previous scenarios for the evolution of the BBB typically adopt a classic, now discredited 'scala naturae' approach, which inaccurately describes a putative evolutionary progression of the mammalian BBB from simple invertebrates to mammals. In fact, BBB-like structures have evolved independently numerous times, complicating simplistic views of the evolution of the BBB as a linear process. Here, we review BBBs in their various forms in both invertebrates and vertebrates, with an emphasis on the function, evolution, and conditional relevance of popular animal models such as the fruit fly and the zebrafish to mammalian BBB research.
Collapse
Affiliation(s)
- Alicia D. Dunton
- Developmental Integrative Biology Group, Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA; (T.G.); (W.B.)
- Correspondence:
| | - Torben Göpel
- Developmental Integrative Biology Group, Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA; (T.G.); (W.B.)
| | - Dao H. Ho
- Department of Clinical Investigation, Tripler Army Medical Center, Honolulu, HI 96859, USA;
| | - Warren Burggren
- Developmental Integrative Biology Group, Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA; (T.G.); (W.B.)
| |
Collapse
|
18
|
Neves JH, Rezende-Teixeira P, Palomino NB, Machado-Santelli GM. Molecular and morphological approach to study the innexin gap junctions in Rhynchosciara americana. Open Biol 2021; 11:210224. [PMID: 34753320 PMCID: PMC8580445 DOI: 10.1098/rsob.210224] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Gap junctions mediate communication between adjacent cells and are fundamental to the development and homeostasis in multicellular organisms. In invertebrates, gap junctions are formed by transmembrane proteins called innexins. Gap junctions allow the passage of small molecules through an intercellular channel, between a cell and another adjacent cell. The dipteran Rhynchosciara americana has contributed to studying the biology of invertebrates and the study of the interaction and regulation of genes during biological development. Therefore, this paper aimed to study the R. americana innexin-2 by molecular characterization, analysis of the expression profile and cellular localization. The molecular characterization results confirm that the message is from a gap junction protein and analysis of the expression and cellular localization profile shows that innexin-2 can participate in many physiological processes during the development of R. americana.
Collapse
Affiliation(s)
- Jorge Henrique Neves
- Institute of Biomedical Sciences, University of São Paulo, Avenida Professor Lineu Prestes, 1524 – sala 307, São Paulo, SP, Brazil
| | - Paula Rezende-Teixeira
- Institute of Biomedical Sciences, University of São Paulo, Avenida Professor Lineu Prestes, 1524 – sala 307, São Paulo, SP, Brazil
| | - Natalia Bazan Palomino
- Institute of Biomedical Sciences, University of São Paulo, Avenida Professor Lineu Prestes, 1524 – sala 307, São Paulo, SP, Brazil
| | - Glaucia Maria Machado-Santelli
- Institute of Biomedical Sciences, University of São Paulo, Avenida Professor Lineu Prestes, 1524 – sala 307, São Paulo, SP, Brazil
| |
Collapse
|
19
|
Ding Z, Guo S, Luo L, Zheng Y, Gan S, Kang X, Wu X, Zhu S. Emerging Roles of Microglia in Neuro-vascular Unit: Implications of Microglia-Neurons Interactions. Front Cell Neurosci 2021; 15:706025. [PMID: 34712121 PMCID: PMC8546170 DOI: 10.3389/fncel.2021.706025] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 09/10/2021] [Indexed: 12/20/2022] Open
Abstract
Microglia, which serve as the defensive interface of the nervous system, are activated in many neurological diseases. Their role as immune responding cells has been extensively studied in the past few years. Recent studies have demonstrated that neuronal feedback can be shaped by the molecular signals received and sent by microglia. Altered neuronal activity or synaptic plasticity leads to the release of various communication messages from neurons, which in turn exert effects on microglia. Research on microglia-neuron communication has thus expanded from focusing only on neurons to the neurovascular unit (NVU). This approach can be used to explore the potential mechanism of neurovascular coupling across sophisticated receptor systems and signaling cascades in health and disease. However, it remains unclear how microglia-neuron communication happens in the brain. Here, we discuss the functional contribution of microglia to synapses, neuroimmune communication, and neuronal activity. Moreover, the current state of knowledge of bidirectional control mechanisms regarding interactions between neurons and microglia are reviewed, with a focus on purinergic regulatory systems including ATP-P2RY12R signaling, ATP-adenosine-A1Rs/A2ARs, and the ATP-pannexin 1 hemichannel. This review aims to organize recent studies to highlight the multifunctional roles of microglia within the neural communication network in health and disease.
Collapse
Affiliation(s)
- Zhe Ding
- Department of Anesthesiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Shaohui Guo
- Department of Anesthesiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Lihui Luo
- Department of Anesthesiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yueying Zheng
- Department of Anesthesiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Shuyuan Gan
- Department of Anesthesiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Xianhui Kang
- Department of Anesthesiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiaomin Wu
- Department of Anesthesiology, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, China
| | - Shengmei Zhu
- Department of Anesthesiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| |
Collapse
|
20
|
Activation of Cx43 Hemichannels Induces the Generation of Ca 2+ Oscillations in White Adipocytes and Stimulates Lipolysis. Int J Mol Sci 2021; 22:ijms22158095. [PMID: 34360859 PMCID: PMC8347185 DOI: 10.3390/ijms22158095] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 07/22/2021] [Accepted: 07/26/2021] [Indexed: 12/11/2022] Open
Abstract
The aim of the study was to investigate the mechanisms of Ca2+ oscillation generation upon activation of connexin-43 and regulation of the lipolysis/lipogenesis balance in white adipocytes through vesicular ATP release. With fluorescence microscopy it was revealed that a decrease in the concentration of extracellular calcium ([Ca2+]ex) results in two types of Ca2+ responses in white adipocytes: Ca2+ oscillations and transient Ca2+ signals. It was found that activation of the connexin half-channels is involved in the generation of Ca2+ oscillations, since the blockers of the connexin hemichannels-carbenoxolone, octanol, proadifen and Gap26-as well as Cx43 gene knockdown led to complete suppression of these signals. The activation of Cx43 in response to the reduction of [Ca2+]ex was confirmed by TIRF microscopy. It was shown that in response to the activation of Cx43, ATP-containing vesicles were released from the adipocytes. This process was suppressed by knockdown of the Cx43 gene and by bafilomycin A1, an inhibitor of vacuolar ATPase. At the level of intracellular signaling, the generation of Ca2+ oscillations in white adipocytes in response to a decrease in [Ca2+]ex occurred due to the mobilization of the Ca2+ ions from the thapsigargin-sensitive Ca2+ pool of IP3R as a result of activation of the purinergic P2Y1 receptors and phosphoinositide signaling pathway. After activation of Cx43 and generation of the Ca2+ oscillations, changes in the expression levels of key genes and their encoding proteins involved in the regulation of lipolysis were observed in white adipocytes. This effect was accompanied by a decrease in the number of adipocytes containing lipid droplets, while inhibition or knockdown of Cx43 led to inhibition of lipolysis and accumulation of lipid droplets. In this study, we investigated the mechanism of Ca2+ oscillation generation in white adipocytes in response to a decrease in the concentration of Ca2+ ions in the external environment and established an interplay between periodic Ca2+ modes and the regulation of the lipolysis/lipogenesis balance.
Collapse
|
21
|
Identification and classification of innexin gene transcripts in the central nervous system of the terrestrial slug Limax valentianus. PLoS One 2021; 16:e0244902. [PMID: 33857131 PMCID: PMC8049302 DOI: 10.1371/journal.pone.0244902] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 03/09/2021] [Indexed: 12/20/2022] Open
Abstract
Intercellular gap junction channels and single-membrane channels have been reported to regulate electrical synapse and the brain function. Innexin is known as a gap junction-related protein in invertebrates and is involved in the formation of intercellular gap junction channels and single-cell membrane channels. Multiple isoforms of innexin protein in each species enable the precise regulation of channel function. In molluscan species, sequence information of innexins is still limited and the sequences of multiple innexin isoforms have not been classified. This study examined the innexin transcripts expressed in the central nervous system of the terrestrial slug Limax valentianus and identified 16 transcripts of 12 innexin isoforms, including the splicing variants. We performed phylogenetic analysis and classified the isoforms with other molluscan innexin sequences. Next, the phosphorylation, N-glycosylation, and S-nitrosylation sites were predicted to characterize the innexin isoforms. Further, we identified 16 circular RNA sequences of nine innexin isoforms in the central nervous system of Limax. The identification and classification of molluscan innexin isoforms provided novel insights for understanding the regulatory mechanism of innexin in this phylum.
Collapse
|
22
|
Abstract
Connexins are a family of gap junction forming proteins widely expressed by mammalian cells. They assemble into hexameric hemichannels, which can either function independently or dock with opposing hemichannels on apposite cells, forming a gap junction. Pannexins are structurally related to the connexins but extensive glycosylation of these channels prevents docking to form gap junctions and they function as membrane channels. Platelets express pannexin-1 and several connexin family members (Cx37, Cx40 and Cx62). These channels are permeable to molecules up to 1,000 Daltons in molecular mass and functional studies demonstrate their role in non-vesicular ATP release. Channel activation is regulated by (patho)physiological stimuli, such as mechanical stimulation, making them attractive potential drug targets for the management of arterial thrombosis. This review explores the structure and function of platelet pannexin-1 and connexins, the mechanisms by which they are gated and their therapeutic potential.
Collapse
Affiliation(s)
- Kirk A Taylor
- Institute for Cardiovascular and Metabolic Research, University of Reading, Reading, UK.,National Heart and Lung Institute, Imperial College London, London, UK
| | - Gemma Little
- Institute for Cardiovascular and Metabolic Research, University of Reading, Reading, UK
| | - Jonathan M Gibbins
- Institute for Cardiovascular and Metabolic Research, University of Reading, Reading, UK
| |
Collapse
|
23
|
Schall JD, Paré M. The unknown but knowable relationship between Presaccadic Accumulation of activity and Saccade initiation. J Comput Neurosci 2021; 49:213-228. [PMID: 33712942 DOI: 10.1007/s10827-021-00784-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 01/06/2021] [Accepted: 02/16/2021] [Indexed: 12/01/2022]
Abstract
The goal of this short review is to call attention to a yawning gap of knowledge that separates two processes essential for saccade production. On the one hand, knowledge about the saccade generation circuitry within the brainstem is detailed and precise - push-pull interactions between gaze-shifting and gaze-holding processes control the time of saccade initiation, which begins when omnipause neurons are inhibited and brainstem burst neurons are excited. On the other hand, knowledge about the cortical and subcortical premotor circuitry accomplishing saccade initiation has crystalized around the concept of stochastic accumulation - the accumulating activity of saccade neurons reaching a fixed value triggers a saccade. Here is the gap: we do not know how the reaching of a threshold by premotor neurons causes the critical pause and burst of brainstem neurons that initiates saccades. Why this problem matters and how it can be addressed will be discussed. Closing the gap would unify two rich but curiously disconnected empirical and theoretical domains.
Collapse
Affiliation(s)
- Jeffrey D Schall
- Centre for Vision Research, Vision Science to Application, Department of Biology, York University, Ontario, M3J 1P3, Toronto, Canada.
| | - Martin Paré
- Department of Biomedical & Molecular Sciences and of Psychology, Queen's University, Ontario, ON K7L 3N6, Kingston, Canada
| |
Collapse
|
24
|
Zefferino R, Piccoli C, Di Gioia S, Capitanio N, Conese M. How Cells Communicate with Each Other in the Tumor Microenvironment: Suggestions to Design Novel Therapeutic Strategies in Cancer Disease. Int J Mol Sci 2021; 22:ijms22052550. [PMID: 33806300 PMCID: PMC7961918 DOI: 10.3390/ijms22052550] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 02/25/2021] [Accepted: 02/26/2021] [Indexed: 02/06/2023] Open
Abstract
Connexin- and pannexin (Panx)-formed hemichannels (HCs) and gap junctions (GJs) operate an interaction with the extracellular matrix and GJ intercellular communication (GJIC), and on account of this they are involved in cancer onset and progression towards invasiveness and metastatization. When we deal with cancer, it is not correct to omit the immune system, as well as neglecting its role in resisting or succumbing to formation and progression of incipient neoplasia until the formation of micrometastasis, nevertheless what really occurs in the tumor microenvironment (TME), which are the main players and which are the tumor or body allies, is still unclear. The goal of this article is to discuss how the pivotal players act, which can enhance or contrast cancer progression during two important process: "Activating Invasion and Metastasis" and the "Avoiding Immune Destruction", with a particular emphasis on the interplay among GJIC, Panx-HCs, and the purinergic system in the TME without disregarding the inflammasome and cytokines thereof derived. In particular, the complex and contrasting roles of Panx1/P2X7R signalosome in tumor facilitation and/or inhibition is discussed in regard to the early/late phases of the carcinogenesis. Finally, considering this complex interplay in the TME between cancer cells, stromal cells, immune cells, and focusing on their means of communication, we should be capable of revealing harmful messages that help the cancer growth and transform them in body allies, thus designing novel therapeutic strategies to fight cancer in a personalized manner.
Collapse
Affiliation(s)
- Roberto Zefferino
- Department of Medical and Surgical Sciences, University of Foggia, 71122 Foggia, Italy; (S.D.G.); (M.C.)
- Correspondence: ; Tel.: +39-0881-884673
| | - Claudia Piccoli
- Department of Clinical and Experimental Medicine, University of Foggia, 71122 Foggia, Italy; (C.P.); (N.C.)
| | - Sante Di Gioia
- Department of Medical and Surgical Sciences, University of Foggia, 71122 Foggia, Italy; (S.D.G.); (M.C.)
| | - Nazzareno Capitanio
- Department of Clinical and Experimental Medicine, University of Foggia, 71122 Foggia, Italy; (C.P.); (N.C.)
| | - Massimo Conese
- Department of Medical and Surgical Sciences, University of Foggia, 71122 Foggia, Italy; (S.D.G.); (M.C.)
| |
Collapse
|
25
|
Thakore P, Alvarado MG, Ali S, Mughal A, Pires PW, Yamasaki E, Pritchard HA, Isakson BE, Tran CHT, Earley S. Brain endothelial cell TRPA1 channels initiate neurovascular coupling. eLife 2021; 10:63040. [PMID: 33635784 PMCID: PMC7935492 DOI: 10.7554/elife.63040] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 02/25/2021] [Indexed: 02/07/2023] Open
Abstract
Cerebral blood flow is dynamically regulated by neurovascular coupling to meet the dynamic metabolic demands of the brain. We hypothesized that TRPA1 channels in capillary endothelial cells are stimulated by neuronal activity and instigate a propagating retrograde signal that dilates upstream parenchymal arterioles to initiate functional hyperemia. We find that activation of TRPA1 in capillary beds and post-arteriole transitional segments with mural cell coverage initiates retrograde signals that dilate upstream arterioles. These signals exhibit a unique mode of biphasic propagation. Slow, short-range intercellular Ca2+ signals in the capillary network are converted to rapid electrical signals in transitional segments that propagate to and dilate upstream arterioles. We further demonstrate that TRPA1 is necessary for functional hyperemia and neurovascular coupling within the somatosensory cortex of mice in vivo. These data establish endothelial cell TRPA1 channels as neuronal activity sensors that initiate microvascular vasodilatory responses to redirect blood to regions of metabolic demand.
Collapse
Affiliation(s)
- Pratish Thakore
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, United States
| | - Michael G Alvarado
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, United States
| | - Sher Ali
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, United States
| | - Amreen Mughal
- Department of Pharmacology, College of Medicine, University of Vermont, Burlington, United States
| | - Paulo W Pires
- Department of Physiology, College of Medicine, University of Arizona, Tucson, United States
| | - Evan Yamasaki
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, United States
| | - Harry At Pritchard
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, United States.,Institute of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Brant E Isakson
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, United States.,Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, United States
| | - Cam Ha T Tran
- Department of Physiology & Cell Biology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, United States
| | - Scott Earley
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, United States
| |
Collapse
|
26
|
Bhat EA, Sajjad N. Human Pannexin 1 channel: Insight in structure-function mechanism and its potential physiological roles. Mol Cell Biochem 2021; 476:1529-1540. [PMID: 33394272 DOI: 10.1007/s11010-020-04002-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 11/21/2020] [Indexed: 12/15/2022]
Abstract
Pannexins, large non-gap junction super family exists in vertebrates, play multiple roles in different cellular functions through their ATP release. Panx1-mediated adenosine 5'-triphosphate (ATP) release plays a vital role in physiological and pathophysiological conditions and is known major extracellular molecule in purinergic signaling. To modulate their function in vivo, a proper regulation of channel is necessary. Post-translational modifications are considered to be some regulating mechanisms for PANX1, while PANX2, PANX3 have been uncharacterized to date. Through their significant evidences, PANXs exclude from gap junction and conduits ATP release and other cellular molecules from cells by various mechanisms. PANX1 is most extensive characterized and implicated in ATP signaling and inflammatory processes. Despite the constant advances, much significance of PANX1 in physiological processes remains elusive. Recently, various research groups along with our group have reported the Cryo-EM structure of Panx1 channel and uncovered the hidden functions in structure-function mechanism as well as to provide the clear understanding in physiological and pathophysiological roles. These research groups reported the novel heptameric structure with contains 4 transmembrane helices (TM), two extracellular loops and one intracellular loop with N and C terminus located at the intracellular side. In addition, the structure contains a large pore of which an inhibitor CBX act as a plug that blocking the passage of substrate. In this context, this review will present current mechanistic understanding in structure and function together with significant physiological roles particularly ATP release in health and disease. As such, this review emphasizes on recent functional properties associated with novel heptameric channel and demystifies channel-mediated ATP release function.
Collapse
Affiliation(s)
- Eijaz Ahmed Bhat
- Life Science Institute, Zhejiang University, Hangzhou, 310058, Zhejiang, People's Republic of China.
| | - Nasreena Sajjad
- Department of Biochemistry, University of Kashmir, Hazratbal, Jammu and Kashmir, India
| |
Collapse
|
27
|
Acosta ML, Mat Nor MN, Guo CX, Mugisho OO, Coutinho FP, Rupenthal ID, Green CR. Connexin therapeutics: blocking connexin hemichannel pores is distinct from blocking pannexin channels or gap junctions. Neural Regen Res 2021; 16:482-488. [PMID: 32985469 PMCID: PMC7996017 DOI: 10.4103/1673-5374.290097] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Compounds that block the function of connexin and pannexin protein channels have been suggested to be valuable therapeutics for a range of diseases. Some of these compounds are now in clinical trials, but for many of them, the literature is inconclusive about the molecular effect on the tissue, despite evidence of functional recovery. Blocking the different channel types has distinct physiological and pathological implications and this review describes current knowledge of connexin and pannexin protein channels, their function as channels and possible mechanisms of the channel block effect for the latest therapeutic compounds. We summarize the evidence implicating pannexins and connexins in disease, considering their homeostatic versus pathological roles, their contribution to excesive ATP release linked to disease onset and progression.
Collapse
Affiliation(s)
- Monica L Acosta
- School of Optometry and Vision Science; New Zealand National Eye Centre, University of Auckland; Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland; Brain Research New Zealand-Rangahau Roro Aotearoa, Auckland, New Zealand
| | - Mohd N Mat Nor
- School of Optometry and Vision Science, University of Auckland, Auckland, New Zealand; Faculty of Medicine, Universiti Sultan Zainal Abidin, Terengganu, Malaysia
| | - Cindy X Guo
- School of Optometry and Vision Science, University of Auckland, Auckland, New Zealand
| | - Odunayo O Mugisho
- Department of Ophthalmology, University of Auckland; Buchanan Ocular Therapeutics Unit, Department of Ophthalmology; New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand
| | - Frazer P Coutinho
- Department of Ophthalmology, University of Auckland, Auckland, New Zealand
| | - Ilva D Rupenthal
- Department of Ophthalmology, University of Auckland; Buchanan Ocular Therapeutics Unit, Department of Ophthalmology; New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand
| | - Colin R Green
- Department of Ophthalmology; New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand
| |
Collapse
|
28
|
Kordowitzki P, Kranc W, Bryl R, Kempisty B, Skowronska A, Skowronski MT. The Relevance of Aquaporins for the Physiology, Pathology, and Aging of the Female Reproductive System in Mammals. Cells 2020; 9:cells9122570. [PMID: 33271827 PMCID: PMC7760214 DOI: 10.3390/cells9122570] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 11/23/2020] [Accepted: 11/29/2020] [Indexed: 12/26/2022] Open
Abstract
Aquaporins constitute a group of water channel proteins located in numerous cell types. These are pore-forming transmembrane proteins, which mediate the specific passage of water molecules through membranes. It is well-known that water homeostasis plays a crucial role in different reproductive processes, e.g., oocyte transport, hormonal secretion, completion of successful fertilization, blastocyst formation, pregnancy, and birth. Further, aquaporins are involved in the process of spermatogenesis, and they have been reported to be involved during the storage of spermatozoa. It is noteworthy that aquaporins are relevant for the physiological function of specific parts in the female reproductive system, which will be presented in detail in the first section of this review. Moreover, they are relevant in different pathologies in the female reproductive system. The contribution of aquaporins in selected reproductive disorders and aging will be summarized in the second section of this review, followed by a section dedicated to aquaporin-related proteins. Since the relevance of aquaporins for the male reproductive system has been reviewed several times in the recent past, this review aims to provide an update on the distribution and impact of aquaporins only in the female reproductive system. Therefore, this paper seeks to determine the physiological and patho-physiological relevance of aquaporins on female reproduction, and female reproductive aging.
Collapse
Affiliation(s)
- Paweł Kordowitzki
- Department of Basic and Preclinical Sciences, Institute for Veterinary Medicine, Nicolaus Copernicus University, 87-100 Torun, Poland;
- Institute of Animal Reproduction and Food Research of Polish Academy of Sciences, 10-243 Olsztyn, Poland
| | - Wiesława Kranc
- Department of Anatomy, Poznan University of Medical Sciences, 60-781 Poznan, Poland; (W.K.); (R.B.); (B.K.)
| | - Rut Bryl
- Department of Anatomy, Poznan University of Medical Sciences, 60-781 Poznan, Poland; (W.K.); (R.B.); (B.K.)
| | - Bartosz Kempisty
- Department of Anatomy, Poznan University of Medical Sciences, 60-781 Poznan, Poland; (W.K.); (R.B.); (B.K.)
- Department of Histology and Embryology, Poznan University of Medical Sciences, 60-781 Poznan, Poland
- Department of Veterinary Surgery, Institute for Veterinary Medicine, Nicolaus Copernicus University, 87-100 Torun, Poland
| | - Agnieszka Skowronska
- Department of Human Physiology and Pathophysiology, School of Medicine, Collegium Medicum, University of Warmia and Mazury, Warszawska Street 30, 10-082 Olsztyn, Poland;
| | - Mariusz T. Skowronski
- Department of Basic and Preclinical Sciences, Institute for Veterinary Medicine, Nicolaus Copernicus University, 87-100 Torun, Poland;
- Correspondence: ; Tel.: +48-56-611-2231
| |
Collapse
|
29
|
Choi DW. Excitotoxicity: Still Hammering the Ischemic Brain in 2020. Front Neurosci 2020; 14:579953. [PMID: 33192266 PMCID: PMC7649323 DOI: 10.3389/fnins.2020.579953] [Citation(s) in RCA: 91] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 09/25/2020] [Indexed: 12/13/2022] Open
Abstract
Interest in excitotoxicity expanded following its implication in the pathogenesis of ischemic brain injury in the 1980s, but waned subsequent to the failure of N-methyl-D-aspartate (NMDA) antagonists in high profile clinical stroke trials. Nonetheless there has been steady progress in elucidating underlying mechanisms. This review will outline the historical path to current understandings of excitotoxicity in the ischemic brain, and suggest that this knowledge should be leveraged now to develop neuroprotective treatments for stroke.
Collapse
Affiliation(s)
- Dennis W Choi
- Department of Neurology, SUNY Stony Brook, Stony Brook, NY, United States
| |
Collapse
|
30
|
Liu W, Cui Y, Wei J, Sun J, Zheng L, Xie J. Gap junction-mediated cell-to-cell communication in oral development and oral diseases: a concise review of research progress. Int J Oral Sci 2020; 12:17. [PMID: 32532966 PMCID: PMC7293327 DOI: 10.1038/s41368-020-0086-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 04/30/2020] [Accepted: 05/19/2020] [Indexed: 02/05/2023] Open
Abstract
Homoeostasis depends on the close connection and intimate molecular exchange between extracellular, intracellular and intercellular networks. Intercellular communication is largely mediated by gap junctions (GJs), a type of specialized membrane contact composed of variable number of channels that enable direct communication between cells by allowing small molecules to pass directly into the cytoplasm of neighbouring cells. Although considerable evidence indicates that gap junctions contribute to the functions of many organs, such as the bone, intestine, kidney, heart, brain and nerve, less is known about their role in oral development and disease. In this review, the current progress in understanding the background of connexins and the functions of gap junctions in oral development and diseases is discussed. The homoeostasis of tooth and periodontal tissues, normal tooth and maxillofacial development, saliva secretion and the integrity of the oral mucosa depend on the proper function of gap junctions. Knowledge of this pattern of cell-cell communication is required for a better understanding of oral diseases. With the ever-increasing understanding of connexins in oral diseases, therapeutic strategies could be developed to target these membrane channels in various oral diseases and maxillofacial dysplasia.
Collapse
Affiliation(s)
- Wenjing Liu
- State Key Laboratory of Oral Diseases & National Clinical Center for Oral Diseases & West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yujia Cui
- State Key Laboratory of Oral Diseases & National Clinical Center for Oral Diseases & West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Jieya Wei
- State Key Laboratory of Oral Diseases & National Clinical Center for Oral Diseases & West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Jianxun Sun
- State Key Laboratory of Oral Diseases & National Clinical Center for Oral Diseases & West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Liwei Zheng
- State Key Laboratory of Oral Diseases & National Clinical Center for Oral Diseases & West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Jing Xie
- State Key Laboratory of Oral Diseases & National Clinical Center for Oral Diseases & West China Hospital of Stomatology, Sichuan University, Chengdu, China.
| |
Collapse
|
31
|
Pannexin-1 Channel Regulates ATP Release in Epilepsy. Neurochem Res 2020; 45:965-971. [PMID: 32170674 DOI: 10.1007/s11064-020-02981-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 01/16/2020] [Accepted: 02/01/2020] [Indexed: 12/28/2022]
Abstract
With the deepening of research on epilepsy in recent decades, great progress has been made in the diagnosis and treatment of the disease. However, the clinical outcome remains unsatisfactory due to the confounding symptoms and complications, as well as complex intrinsic pathogenesis. A better understanding of the pathogenesis of epilepsy should be able to hinder the progress of the disease and improve the therapeutic effectiveness. Since the discovery of pannexin (Panx), unremitting efforts on the study of this gap junction protein family member have revealed its role in participating in the expression of various physiopathological processes. Among them, the activation or inhibition of Panx channel has been shown to regulate the release of adenosine triphosphate (ATP) and other signals, which is very important for the onset and control of nervous system diseases including epilepsy. In this article, we summarize the factors influencing the regulation of Panx channel opening, hoping to find a way to interfere with the activation or inhibition of Panx channel that regulates the signal transduction of ATP and other factors so as to control the progression of epilepsy and improve the quality of life of epileptic patients who fail to respond to the existing medical therapies and those at risk of surgical treatment.
Collapse
|
32
|
Tsukamoto S, Emmei T, Nakano S, Nishio N, Sasakura H, Mori I. The Caenorhabditis elegans INX-4/Innexin is required for the fine-tuning of temperature orientation in thermotaxis behavior. Genes Cells 2020; 25:154-164. [PMID: 31917862 PMCID: PMC7078936 DOI: 10.1111/gtc.12745] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 12/27/2019] [Accepted: 12/28/2019] [Indexed: 01/10/2023]
Abstract
Innexins in invertebrates are considered to play roles similar to those of connexins and pannexins in vertebrates. However, it remains poorly understood how innexins function in biological phenomena including their function in the nervous systems. Here, we identified inx‐4, a member of the innexin family in C. elegans, by a forward screening of thermotaxis‐defective mutants. The inx‐4 mutants exhibited abnormal migration to a temperature slightly higher than the cultivation temperature, called mild thermophilic behavior. Rescue experiments revealed that INX‐4 acts in the major thermosensory neuron AFD to regulate thermotaxis behavior. INX‐4::GFP fusion protein localized exclusively along axons in AFD neurons. In addition, over‐expression of INX‐4 in AFD neurons induced a cryophilic behavior, which is opposite to inx-4 mutants. Our findings suggest that INX‐4/Innexin in AFD may fine‐tune the execution of thermotaxis behavior when moving to desired temperatures.
Collapse
Affiliation(s)
- Satomi Tsukamoto
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Taishi Emmei
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Shunji Nakano
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan.,Neuroscience Institute, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Nana Nishio
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Hiroyuki Sasakura
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Ikue Mori
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan.,Neuroscience Institute, Graduate School of Science, Nagoya University, Nagoya, Japan
| |
Collapse
|
33
|
Aguilar-Perez A, Pacheco-Costa R, Atkinson EG, Deosthale P, Davis HM, Essex AL, Dilley JE, Gomez L, Rupert JE, Zimmers TA, Thompson RJ, Allen MR, Plotkin LI. Age- and sex-dependent role of osteocytic pannexin1 on bone and muscle mass and strength. Sci Rep 2019; 9:13903. [PMID: 31554905 PMCID: PMC6761284 DOI: 10.1038/s41598-019-50444-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 09/11/2019] [Indexed: 12/25/2022] Open
Abstract
Pannexins (Panxs), glycoproteins that oligomerize to form hemichannels on the cell membrane, are topologically similar to connexins, but do not form cell-to-cell gap junction channels. There are 3 members of the family, 1-3, with Panx1 being the most abundant. All Panxs are expressed in bone, but their role in bone cell biology is not completely understood. We now report that osteocytic Panx1 deletion (Panx1Δot) alters bone mass and strength in female mice. Bone mineral density after reaching skeletal maturity is higher in female Panx1Δot mice than in control Panx1fl/fl mice. Further, osteocytic Panx1 deletion partially prevented aging effects on cortical bone structure and mechanical properties. Young 4-month-old female Panx1Δot mice exhibited increased lean body mass, even though pannexin levels in skeletal muscle were not affected; whereas no difference in lean body mass was detected in male mice. Furthermore, female Panx1-deficient mice exhibited increased muscle mass without changes in strength, whereas Panx1Δot males showed unchanged muscle mass and decreased in vivo maximum plantarflexion torque, indicating reduced muscle strength. Our results suggest that osteocytic Panx1 deletion increases bone mass in young and old female mice and muscle mass in young female mice, but has deleterious effects on muscle strength only in males.
Collapse
Affiliation(s)
- Alexandra Aguilar-Perez
- Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Rafael Pacheco-Costa
- Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Emily G Atkinson
- Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Padmini Deosthale
- Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Hannah M Davis
- Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Alyson L Essex
- Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Julian E Dilley
- Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Leland Gomez
- Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Joseph E Rupert
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Teresa A Zimmers
- Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
- Indiana Center for Musculoskeletal Health, Indianapolis, IN, 46202, USA
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
- Indiana University Simon Cancer Center, Indianapolis, IN, 46202, USA
| | - Roger J Thompson
- Hotchkiss Brain Institute, Department of Cell Biology and Anatomy, University of Calgary, Calgary, Alberta, Canada
| | - Matthew R Allen
- Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
- Roudebush Veterans Administration Medical Center, Indianapolis, IN, 46202, USA
| | - Lilian I Plotkin
- Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
- Roudebush Veterans Administration Medical Center, Indianapolis, IN, 46202, USA.
- Indiana Center for Musculoskeletal Health, Indianapolis, IN, 46202, USA.
| |
Collapse
|
34
|
Stylianaki EA, Karpouzis A, Tripsianis G, Veletza S. Assessment of Gap Junction Protein Beta-2 rs3751385 Gene Polymorphism in Psoriasis Vulgaris. J Clin Med Res 2019; 11:642-650. [PMID: 31523338 PMCID: PMC6731047 DOI: 10.14740/jocmr3845] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 06/25/2019] [Indexed: 02/05/2023] Open
Abstract
Background Gap junction protein beta 2 (GJB2) upregulation in psoriasis transcriptome analysis as well as connexin 26 (Cx26, encoded by GJB2) expression upregulation in psoriatic plaques has already been substantiated. GJB2 rs72474224 and rs3751385 have been correlated with psoriasis vulgaris incidence in Chinese populations. Here we study the effect of rs3751385 in patients suffering from psoriasis vulgaris in a Caucasian Greek population at the prefecture of Thrace in Northern Greece. Methods One hundred and seventy-three (111 males and 62 females) psoriatic patients (108 were of early-onset psoriasis) and 171 matched controls were included in the study. Genomic DNA was extracted from peripheral blood leukocytes and genotyping was carried out by polymerase chain reaction-restriction-fragment length polymorphism (PCR-RFLP). Results A statistically significant lower frequency of C/T genotype in late-onset male psoriasis vulgaris (P = 0.029) as well as of T allele in female early-onset psoriasis vulgaris (P = 0.049) were ascertained. Conclusions On condition that all other genetic or environmental factors remain stable, the existence and possible interaction between GJB2 rs3751385 C and T alleles in male psoriatic patients may be considered as protective gene component against late-onset psoriasis appearance, while presence of the T allele in female might block the histogenetic mechanisms of early-onset psoriasis lesions.
Collapse
Affiliation(s)
- Elli-Anna Stylianaki
- Department of Biology, Faculty of Medicine, Democritus University of Thrace, Alexandroupolis, Greece
| | - Anthony Karpouzis
- Department of Dermatology, Faculty of Medicine, Democritus University of Thrace, Alexandroupolis, Greece
| | - Gregory Tripsianis
- Department of Medical Statistics, Faculty of Medicine, Democritus University of Thrace, Alexandroupolis, Greece
| | - Stavroula Veletza
- Department of Biology, Faculty of Medicine, Democritus University of Thrace, Alexandroupolis, Greece
| |
Collapse
|
35
|
Ziraldo G, Buratto D, Kuang Y, Xu L, Carrer A, Nardin C, Chiani F, Salvatore AM, Paludetti G, Lerner RA, Yang G, Zonta F, Mammano F. A Human-Derived Monoclonal Antibody Targeting Extracellular Connexin Domain Selectively Modulates Hemichannel Function. Front Physiol 2019; 10:392. [PMID: 31263420 PMCID: PMC6584803 DOI: 10.3389/fphys.2019.00392] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 03/21/2019] [Indexed: 11/30/2022] Open
Abstract
Connexin hemichannels, which are plasma membrane hexameric channels (connexons) composed of connexin protein protomers, have been implicated in a host of physiological processes and pathological conditions. A number of single point pathological mutations impart a “leaky” character to the affected hemichannels, i.e., make them more active or hyperactive, suggesting that normal physiological condition could be recovered using selective hemichannel inhibitors. Recently, a human-derived monoclonal antibody named abEC1.1 has been shown to inhibit both wild type and hyperactive hemichannels composed of human (h) connexin 26 (hCx26) subunits. The aims of this work were (1) to characterize further the ability of abEC1.1 to selectively modulate connexin hemichannel function and (2) to assess its in vitro stability in view of future translational applications. In silico analysis of abEC1.1 interaction with the hCx26 hemichannel identified critically important extracellular domain amino acids that are conserved in connexin 30 (hCx30) and connexin 32 (hCx32). Patch clamp experiments performed in HeLa DH cells confirmed the inhibition efficiency of abEC1.1 was comparable for hCx26, hCx30 and hCx32 hemichannels. Of note, even a single amino acid difference in the putative binding region reduced drastically the inhibitory effects of the antibody on all the other tested hemichannels, namely hCx30.2/31.3, hCx30.3, hCx31, hCx31.1, hCx37, hCx43 and hCx45. Plasma membrane channels composed of pannexin 1 were not affected by abEC1.1. Finally, size exclusion chromatography assays showed the antibody does not aggregate appreciably in vitro. Altogether, these results indicate abEC1.1 is a promising tool for further translational studies.
Collapse
Affiliation(s)
- Gaia Ziraldo
- CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy.,Institute of Otolaryngology, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Damiano Buratto
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China
| | - Yuanyuan Kuang
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China
| | - Liang Xu
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China
| | - Andrea Carrer
- CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy.,Department of Physics and Astronomy "G. Galilei", University of Padova, Padua, Italy
| | - Chiara Nardin
- CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy.,Department of Physics and Astronomy "G. Galilei", University of Padova, Padua, Italy
| | - Francesco Chiani
- CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy
| | | | - Gaetano Paludetti
- Institute of Otolaryngology, Università Cattolica del Sacro Cuore, Rome, Italy.,Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Richard A Lerner
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China
| | - Guang Yang
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China
| | - Francesco Zonta
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China
| | - Fabio Mammano
- CNR Institute of Cell Biology and Neurobiology, Monterotondo, Italy.,Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai, China.,Department of Physics and Astronomy "G. Galilei", University of Padova, Padua, Italy
| |
Collapse
|
36
|
Abudara V, Retamal MA, Del Rio R, Orellana JA. Synaptic Functions of Hemichannels and Pannexons: A Double-Edged Sword. Front Mol Neurosci 2018; 11:435. [PMID: 30564096 PMCID: PMC6288452 DOI: 10.3389/fnmol.2018.00435] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 11/08/2018] [Indexed: 01/18/2023] Open
Abstract
The classical view of synapses as the functional contact between presynaptic and postsynaptic neurons has been challenged in recent years by the emerging regulatory role of glial cells. Astrocytes, traditionally considered merely supportive elements are now recognized as active modulators of synaptic transmission and plasticity at the now so-called "tripartite synapse." In addition, an increasing body of evidence indicates that beyond immune functions microglia also participate in various processes aimed to shape synaptic plasticity. Release of neuroactive compounds of glial origin, -process known as gliotransmission-, constitute a widespread mechanism through which glial cells can either potentiate or reduce the synaptic strength. The prevailing vision states that gliotransmission depends on an intracellular Ca2+/exocytotic-mediated release; notwithstanding, growing evidence is pointing at hemichannels (connexons) and pannexin channels (pannexons) as alternative non-vesicular routes for gliotransmitters efflux. In concurrence with this novel concept, both hemichannels and pannexons are known to mediate the transfer of ions and signaling molecules -such as ATP and glutamate- between the cytoplasm and the extracellular milieu. Importantly, recent reports show that glial hemichannels and pannexons are capable to perceive synaptic activity and to respond to it through changes in their functional state. In this article, we will review the current information supporting the "double edge sword" role of hemichannels and pannexons in the function of central and peripheral synapses. At one end, available data support the idea that these channels are chief components of a feedback control mechanism through which gliotransmitters adjust the synaptic gain in either resting or stimulated conditions. At the other end, we will discuss how the excitotoxic release of gliotransmitters and [Ca2+]i overload linked to the opening of hemichannels/pannexons might impact cell function and survival in the nervous system.
Collapse
Affiliation(s)
- Verónica Abudara
- Departamento de Fisiología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Mauricio A Retamal
- Centro de Fisiología Celular e Integrativa, Facultad de Medicina, Clínica Alemana Universidad del Desarrollo, Santiago, Chile.,Department of Cell Physiology and Molecular Biophysics, Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, TX, United States.,Programa de Comunicación Celular en Cáncer, Instituto de Ciencias e Innovación en Medicina, Santiago, Chile
| | - Rodrigo Del Rio
- Laboratory of Cardiorespiratory Control, Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Envejecimiento y Regeneración, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Excelencia en Biomedicina de Magallanes, Universidad de Magallanes, Punta Arenas, Chile
| | - Juan A Orellana
- Departamento de Neurología, Escuela de Medicina and Centro Interdisciplinario de Neurociencias, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Investigación y Estudio del Consumo de Alcohol en Adolescentes, Santiago, Chile
| |
Collapse
|
37
|
Lee VR, Barr KJ, Kelly JJ, Johnston D, Brown CFC, Robb KP, Sayedyahossein S, Huang K, Gros R, Flynn LE, Penuela S. Pannexin 1 regulates adipose stromal cell differentiation and fat accumulation. Sci Rep 2018; 8:16166. [PMID: 30385873 PMCID: PMC6212408 DOI: 10.1038/s41598-018-34234-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 10/11/2018] [Indexed: 12/20/2022] Open
Abstract
Pannexin 1 (Panx1) is a channel-forming glycoprotein important in paracrine signaling and cellular development. In this study, we discovered that mice globally lacking Panx1 (KO) have significantly greater total fat mass and reduced lean mass compared to wild type (WT) mice under a normal diet. Despite having higher fat content, Panx1 KO mice on a high fat diet exhibited no differences in weight gain and blood markers of obesity as compared to WT controls, except for an increase in glucose and insulin levels. However, metabolic cage data revealed that these Panx1 KO mice display significantly increased activity levels, higher ambulatory activity, and reduced sleep duration relative to their WT littermates on a high-fat diet. To uncover the cellular mechanism responsible for the increased fat content in the KO, we isolated primary cultures of adipose-derived stromal cells (ASCs) from WT and KO fat pads. In WT ASCs we observed that Panx1 protein levels increase upon induction into an adipogenic lineage. ASCs isolated from Panx1 KO mice proliferate less but demonstrate enhanced adipogenic differentiation with increased intracellular lipid accumulation, glycerol-3-phosphate dehydrogenase (GPDH) enzyme activity, and adipokine secretion, as compared to WT ASCs. This was consistent with the increased adipocyte size and decreased adipocyte numbers observed in subcutaneous fat of the Panx1 KO mice compared to WT. We concluded that Panx1 plays a key role in adipose stromal cells during the early stages of adipogenic proliferation and differentiation, regulating fat accumulation in vivo.
Collapse
Affiliation(s)
- Vanessa R Lee
- Department of Anatomy & Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, N6A5C1, Canada
| | - Kevin J Barr
- Department of Anatomy & Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, N6A5C1, Canada
| | - John J Kelly
- Department of Anatomy & Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, N6A5C1, Canada
| | - Danielle Johnston
- Department of Anatomy & Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, N6A5C1, Canada
| | - Cody F C Brown
- Department of Anatomy & Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, N6A5C1, Canada
| | - Kevin P Robb
- Biomedical Engineering Graduate Program, University of Western Ontario, London, Ontario, Canada
| | - Samar Sayedyahossein
- Department of Anatomy & Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, N6A5C1, Canada
| | - Kenneth Huang
- Department of Anatomy & Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, N6A5C1, Canada
| | - Robert Gros
- Departments of Physiology and Pharmacology, and of Medicine, University of Western Ontario, London, Ontario, Canada
- Molecular Medicine Research Group Robarts Research Institute, University of Western Ontario, London, Ontario, Canada
| | - Lauren E Flynn
- Department of Anatomy & Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, N6A5C1, Canada
- Department of Chemical and Biochemical Engineering, University of Western Ontario, London, Ontario, Canada
| | - Silvia Penuela
- Department of Anatomy & Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, N6A5C1, Canada.
| |
Collapse
|
38
|
Makarenkova HP, Shah SB, Shestopalov VI. The two faces of pannexins: new roles in inflammation and repair. J Inflamm Res 2018; 11:273-288. [PMID: 29950881 PMCID: PMC6016592 DOI: 10.2147/jir.s128401] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Pannexins belong to a family of ATP-release channels expressed in almost all cell types. An increasing body of literature on pannexins suggests that these channels play dual and sometimes contradictory roles, contributing to normal cell function, as well as to the pathological progression of disease. In this review, we summarize our understanding of pannexin "protective" and "harmful" functions in inflammation, regeneration and mechanical signaling. We also suggest a possible basis for pannexin's dual roles, related to extracellular ATP and K+ levels and the activation of various types of P2 receptors that are associated with pannexin. Finally, we speculate upon therapeutic strategies related to pannexin using eyes, lacrimal glands, and peripheral nerves as examples of interesting therapeutic targets.
Collapse
Affiliation(s)
| | - Sameer B Shah
- Departments of Orthopaedic Surgery and Bioengineering, University of California.,Research Division, Veterans Affairs San Diego Healthcare System, San Diego, CA
| | - Valery I Shestopalov
- Bascom Eye Institute, Department of Ophthalmology, University of Miami, Miami, FL, USA.,Vavilov Institute for General Genetics, Russian Academy of Sciences.,Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia
| |
Collapse
|
39
|
Li S, Bjelobaba I, Stojilkovic SS. Interactions of Pannexin1 channels with purinergic and NMDA receptor channels. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2018; 1860:166-173. [PMID: 28389204 PMCID: PMC5628093 DOI: 10.1016/j.bbamem.2017.03.025] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Revised: 03/28/2017] [Accepted: 03/29/2017] [Indexed: 12/31/2022]
Abstract
Pannexins are a three-member family of vertebrate plasma membrane spanning molecules that have homology to the invertebrate gap junction forming proteins, the innexins. However, pannexins do not form gap junctions but operate as plasma membrane channels. The best-characterized member of these proteins, Pannexin1 (Panx1) was suggested to be functionally associated with purinergic P2X and N-methyl-D-aspartate (NMDA) receptor channels. Activation of these receptor channels by their endogenous ligands leads to cross-activation of Panx1 channels. This in turn potentiates P2X and NMDA receptor channel signaling. Two potentiation concepts have been suggested: enhancement of the current responses and/or sustained receptor channel activation by ATP released through Panx1 pore and adenosine generated by ectonucleotidase-dependent dephosphorylation of ATP. Here we summarize the current knowledge and hypotheses about interactions of Panx1 channels with P2X and NMDA receptor channels. This article is part of a Special Issue entitled: Gap Junction Proteins edited by Jean Claude Herve.
Collapse
Affiliation(s)
- Shuo Li
- Tianjin Key Laboratory of Animal and Plant Resistance, College of Life Sciences, Tianjin Normal University, Tianjin 300387, China
| | - Ivana Bjelobaba
- Institute for Biological Research "Sinisa Stankovic", University of Belgrade, 11000 Belgrade, Serbia
| | - Stanko S Stojilkovic
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD 20892, USA.
| |
Collapse
|
40
|
Willebrords J, Maes M, Crespo Yanguas S, Vinken M. Inhibitors of connexin and pannexin channels as potential therapeutics. Pharmacol Ther 2017; 180:144-160. [PMID: 28720428 PMCID: PMC5802387 DOI: 10.1016/j.pharmthera.2017.07.001] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
While gap junctions support the exchange of a number of molecules between neighboring cells, connexin hemichannels provide communication between the cytosol and the extracellular environment of an individual cell. The latter equally holds true for channels composed of pannexin proteins, which display an architecture reminiscent of connexin hemichannels. In physiological conditions, gap junctions are usually open, while connexin hemichannels and, to a lesser extent, pannexin channels are typically closed, yet they can be activated by a number of pathological triggers. Several agents are available to inhibit channels built up by connexin and pannexin proteins, including alcoholic substances, glycyrrhetinic acid, anesthetics and fatty acids. These compounds not always strictly distinguish between gap junctions, connexin hemichannels and pannexin channels, and may have effects on other targets as well. An exception lies with mimetic peptides, which reproduce specific amino acid sequences in connexin or pannexin primary protein structure. In this paper, a state-of-the-art overview is provided on inhibitors of cellular channels consisting of connexins and pannexins with specific focus on their mode-of-action and therapeutic potential.
Collapse
Affiliation(s)
- Joost Willebrords
- Department of In Vitro Toxicology and Dermato-cosmetology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, Brussels, Belgium
| | - Michaël Maes
- Department of In Vitro Toxicology and Dermato-cosmetology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, Brussels, Belgium
| | - Sara Crespo Yanguas
- Department of In Vitro Toxicology and Dermato-cosmetology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, Brussels, Belgium
| | - Mathieu Vinken
- Department of In Vitro Toxicology and Dermato-cosmetology, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Laarbeeklaan 103, Brussels, Belgium.
| |
Collapse
|
41
|
Nomura T, Taruno A, Shiraishi M, Nakahari T, Inui T, Sokabe M, Eaton DC, Marunaka Y. Current-direction/amplitude-dependent single channel gating kinetics of mouse pannexin 1 channel: a new concept for gating kinetics. Sci Rep 2017; 7:10512. [PMID: 28874774 PMCID: PMC5585217 DOI: 10.1038/s41598-017-10921-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 08/16/2017] [Indexed: 11/25/2022] Open
Abstract
The detailed single-channel gating kinetics of mouse pannexin 1 (mPanx1) remains unknown, although mPanx1 is reported to be a voltage-activated anion-selective channel. We investigated characteristics of single-channel conductances and opening and closing rates of mPanx1 using patch-clamp techniques. The unitary current of mPanx1 shows outward rectification with single-channel conductances of ~20 pS for inward currents and ~80 pS for outward currents. The channel open time for outward currents (Cl- influx) increases linearly as the amplitude of single channel currents increases, while the open time for inward currents (Cl- efflux) is constant irrespective of changes in the current amplitude, as if the direction and amplitude of the unitary current regulates the open time. This is supported by further observations that replacement of extracellular Cl- with gluconate- diminishes the inward tail current (Cl- efflux) at a membrane potential of -100 mV due to the lowered outward current (gluconate- influx) at membrane potential of 100 mV. These results suggest that the direction and rate of charge-carrier movement regulate the open time of mPanx1, and that the previously reported voltage-dependence of Panx1 channel gating is not directly mediated by the membrane potential but rather by the direction and amplitude of currents through the channel.
Collapse
Affiliation(s)
- Takeshi Nomura
- Department of Molecular Cell Physiology, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto, 602-8566, Japan
- Department of Bio-Ionomics, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto, 602-8566, Japan
- Department of Physical Therapy, Faculty of Rehabilitation, Kyushu Nutrition Welfare University, Kitakyushu, 800-0298, Japan
| | - Akiyuki Taruno
- Department of Molecular Cell Physiology, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto, 602-8566, Japan
| | - Makoto Shiraishi
- Department of Molecular Cell Physiology, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto, 602-8566, Japan
| | - Takashi Nakahari
- Department of Molecular Cell Physiology, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto, 602-8566, Japan
- Department of Bio-Ionomics, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto, 602-8566, Japan
- Japan Institute for Food Education and Health, St. Agnes' University, Kyoto, 602-8013, Japan
| | - Toshio Inui
- Department of Molecular Cell Physiology, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto, 602-8566, Japan
- Department of Bio-Ionomics, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto, 602-8566, Japan
- Saisei Mirai Clinics, Moriguchi, 570-0012, Japan
| | - Masahiro Sokabe
- Mechanobiology Laboratory, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
| | - Douglas C Eaton
- Center for Cell & Molecular Signaling, Department of Physiology, Emory University School of Medicine, Atlanta, Georgia, 30322, USA
| | - Yoshinori Marunaka
- Department of Molecular Cell Physiology, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto, 602-8566, Japan.
- Department of Bio-Ionomics, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto, 602-8566, Japan.
- Japan Institute for Food Education and Health, St. Agnes' University, Kyoto, 602-8013, Japan.
| |
Collapse
|
42
|
Epifantseva I, Shaw RM. Intracellular trafficking pathways of Cx43 gap junction channels. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:40-47. [PMID: 28576298 DOI: 10.1016/j.bbamem.2017.05.018] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 05/19/2017] [Accepted: 05/25/2017] [Indexed: 12/11/2022]
Abstract
Gap Junction (GJ) channels, including the most common Connexin 43 (Cx43), have fundamental roles in excitable tissues by facilitating rapid transmission of action potentials between adjacent cells. For instance, synchronization during each heartbeat is regulated by these ion channels at the cardiomyocyte cell-cell border. Cx43 protein has a short half-life, and rapid synthesis and timely delivery of those proteins to particular subdomains are crucial for the cellular organization of gap junctions and maintenance of intracellular coupling. Impairment in gap junction trafficking contributes to dangerous complications in diseased hearts such as the arrhythmias of sudden cardiac death. Of recent interest are the protein-protein interactions with the Cx43 carboxy-terminus. These interactions have significant impact on the full length Cx43 lifecycle and also contribute to trafficking of Cx43 as well as possibly other functions. We are learning that many of the known non-canonical roles of Cx43 can be attributed to the recently identified six endogenous Cx43 truncated isoforms which are produced by internal translation. In general, alternative translation is a new leading edge for proteome expansion and therapeutic drug development. This review highlights recent mechanisms identified in the trafficking of gap junction channels, involvement of other proteins contributing to the delivery of channels to the cell-cell border, and understanding of possible roles of the newly discovered alternatively translated isoforms in Cx43 biology. This article is part of a Special Issue entitled: Gap Junction Proteins edited by Jean Claude Herve.
Collapse
Affiliation(s)
- Irina Epifantseva
- Heart Institute and Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Robin M Shaw
- Heart Institute and Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA.; Department of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA..
| |
Collapse
|
43
|
Valdebenito S, Barreto A, Eugenin EA. The role of connexin and pannexin containing channels in the innate and acquired immune response. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1860:154-165. [PMID: 28559189 DOI: 10.1016/j.bbamem.2017.05.015] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 05/17/2017] [Accepted: 05/25/2017] [Indexed: 12/20/2022]
Abstract
Connexin (Cx) and pannexin (Panx) containing channels - gap junctions (GJs) and hemichannels (HCs) - are present in virtually all cells and tissues. Currently, the role of these channels under physiological conditions is well defined. However, their role in the immune response and pathological conditions has only recently been explored. Data from several laboratories demonstrates that infectious agents, including HIV, have evolved to take advantage of GJs and HCs to improve viral/bacterial replication, enhance inflammation, and help spread toxicity into neighboring areas. In the current review, we discuss the role of Cx and Panx containing channels in immune activation and the pathogenesis of several infectious diseases. This article is part of a Special Issue entitled: Gap Junction Proteins edited by Jean Claude Herve.
Collapse
Affiliation(s)
- Silvana Valdebenito
- Public Health Research Institute (PHRI), Newark, NJ, USA; Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Rutgers the State University of New Jersey, Newark, NJ, USA
| | - Andrea Barreto
- Public Health Research Institute (PHRI), Newark, NJ, USA; Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Rutgers the State University of New Jersey, Newark, NJ, USA
| | - Eliseo A Eugenin
- Public Health Research Institute (PHRI), Newark, NJ, USA; Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Rutgers the State University of New Jersey, Newark, NJ, USA.
| |
Collapse
|
44
|
Xu J, Chen L, Li L. Pannexin hemichannels: A novel promising therapy target for oxidative stress related diseases. J Cell Physiol 2017; 233:2075-2090. [PMID: 28295275 DOI: 10.1002/jcp.25906] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 03/09/2017] [Indexed: 12/16/2022]
Abstract
Pannexins, which contain three subtypes: pannexin-1, -2, and -3, are vertebrate glycoproteins that form non-junctional plasma membrane intracellular hemichannels via oligomerization. Oxidative stress refers to an imbalance of the generation and elimination of reactive oxygen species (ROS). Studies have shown that elevated ROS levels are pivotal in the development of a variety of diseases. Recent studies indicate that the occurrence of these oxidative stress related diseases is associated with pannexin hemichannels. It is also reported that pannexins regulate the production of ROS which in turn may increase the opening of pannexin hemichannels. In this paper, we review recent researches about the important role of pannexin hemichannels in oxidative stress related diseases. Thus, pannexin hemichannels, novel therapeutic targets, hold promise in managing oxidative stress related diseases such as the tumor, inflammatory bowel diseases (IBD), pulmonary fibrosis, chronic obstructive pulmonary disease (COPD), cardiovascular disease, insulin resistance (IR), and neural degeneration diseases.
Collapse
Affiliation(s)
- Jin Xu
- Learning Key Laboratory for Pharmacoproteomics, Institute of Pharmacy and Pharmacology, University of South China, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang, P. R. China
| | - Linxi Chen
- Learning Key Laboratory for Pharmacoproteomics, Institute of Pharmacy and Pharmacology, University of South China, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang, P. R. China
| | - Lanfang Li
- Learning Key Laboratory for Pharmacoproteomics, Institute of Pharmacy and Pharmacology, University of South China, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang, P. R. China
| |
Collapse
|
45
|
Richard M, Bauer R, Tavosanis G, Hoch M. The gap junction protein Innexin3 is required for eye disc growth in Drosophila. Dev Biol 2017; 425:191-207. [PMID: 28390801 DOI: 10.1016/j.ydbio.2017.04.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 03/30/2017] [Accepted: 04/03/2017] [Indexed: 12/23/2022]
Abstract
The Drosophila compound eye develops from a bilayered epithelial sac composed of an upper peripodial epithelium layer and a lower disc proper, the latter giving rise to the eye itself. During larval stages, complex signalling events between the layers contribute to the control of cell proliferation and differentiation in the disc. Previous work in our lab established the gap junction protein Innexin2 (Inx2) as crucial for early larval eye disc growth. By analysing the contribution of other Innexins to eye size control, we have identified Innexin3 (Inx3) as an important growth regulator. Depleting inx3 during larval eye development reduces eye size, while elevating inx3 levels increases eye size, thus phenocopying the inx2 loss- and gain-of-function situation. As demonstrated previously for inx2, inx3 regulates disc cell proliferation and interacts genetically with the Dpp pathway, being required for the proper activation of the Dpp pathway transducer Mad at the furrow and the expression of Dpp receptor Punt in the eye disc. At the developmental timepoint corresponding to eye disc growth, Inx3 colocalises with Inx2 in disc proper and peripodial epithelium cell membranes. In addition, we show that Inx3 protein levels critically depend on inx2 throughout eye development and that inx3 modulates Inx2 protein levels in the larval eye disc. Rescue experiments demonstrate that Inx3 and Inx2 cooperate functionally to enable eye disc growth in Drosophila. Finally, we demonstrate that expression of Inx3 and Inx2 is not only needed in the disc proper but also in the peripodial epithelium to regulate growth of the eye disc. Our data provide a functional demonstration that putative Inx2/Inx3 heteromeric channels regulate organ size.
Collapse
Affiliation(s)
- Mélisande Richard
- Life & Medical Sciences Institute (LIMES) Development, Genetics & Molecular Physiology Unit University of Bonn, Carl-Troll-Straße, 31 53115 Bonn, Germany
| | - Reinhard Bauer
- Life & Medical Sciences Institute (LIMES) Development, Genetics & Molecular Physiology Unit University of Bonn, Carl-Troll-Straße, 31 53115 Bonn, Germany
| | - Gaia Tavosanis
- German Center for Neurodegenerative Diseases (DZNE), Dendrite Differentiation Unit, Sigmund-Freud-Str. 27, 53127 Bonn, Germany
| | - Michael Hoch
- Life & Medical Sciences Institute (LIMES) Development, Genetics & Molecular Physiology Unit University of Bonn, Carl-Troll-Straße, 31 53115 Bonn, Germany.
| |
Collapse
|
46
|
Kumamoto J, Goto M, Nagayama M, Denda M. Real-time imaging of human epidermal calcium dynamics in response to point laser stimulation. J Dermatol Sci 2017; 86:13-20. [PMID: 28119009 DOI: 10.1016/j.jdermsci.2017.01.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 10/24/2016] [Accepted: 01/05/2017] [Indexed: 11/24/2022]
Abstract
BACKGROUND Changes of epidermal calcium ion concentration are involved in regulation of barrier homeostasis and keratinocyte differentiation. Moreover, intracellular calcium dynamics might play a role in skin sensation. But, although calcium dynamics of cultured keratinocytes in response to mechanical stresses has been well studied, calcium propagation in stimulated human epidermis is still poorly understood. OBJECTIVE The aim of this study was to demonstrate a novel method for real-time measurement of calcium dynamics in response to point stimulation of human epidermis at the single-cell level. METHODS We examined calcium propagation in cross-sectional samples of living human epidermis ex vivo, as well as in cultured human keratinocytes, by means of two-photon microscopy after stimulating cells in stratum granulosum with the emission laser of a two-photon microscope. RESULTS Cells in different epidermal layers showed different responses, and those in stratum basale showed the greatest elevation of intracellular calcium. Calcium propagation in epidermis was inhibited in the presence of apyrase (which degrades adenosine triphosphate; ATP) or gap-junction blockers. In cultured keratinocytes, on the other hand, calcium propagated in a simple concentric wave-like manner from the stimulation site, and propagation was strongly suppressed by apyrase. CONCLUSION Our results suggested that ATP and gap junctions play important roles in calcium propagation induced by point laser stimulation of the uppermost layer of epidermis. Our method should be broadly useful to study calcium dynamics, epidermal physiological mechanisms, and mechanisms of skin sensation at the single-cell level.
Collapse
Affiliation(s)
- Junichi Kumamoto
- Japan Science and Technology Agency, CREST, Kawaguchi, Japan; Research Institute for Electronic Science, Hokkaido University, Sapporo, Japan
| | - Makiko Goto
- Japan Science and Technology Agency, CREST, Kawaguchi, Japan; Shiseido Global Innovation Center, Yokohama, Japan.
| | - Masaharu Nagayama
- Japan Science and Technology Agency, CREST, Kawaguchi, Japan; Research Institute for Electronic Science, Hokkaido University, Sapporo, Japan
| | - Mitsuhiro Denda
- Japan Science and Technology Agency, CREST, Kawaguchi, Japan; Shiseido Global Innovation Center, Yokohama, Japan
| |
Collapse
|
47
|
Ullrich F, Reincke SM, Voss FK, Stauber T, Jentsch TJ. Inactivation and Anion Selectivity of Volume-regulated Anion Channels (VRACs) Depend on C-terminal Residues of the First Extracellular Loop. J Biol Chem 2016; 291:17040-8. [PMID: 27325695 DOI: 10.1074/jbc.m116.739342] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Indexed: 11/06/2022] Open
Abstract
Canonical volume-regulated anion channels (VRACs) are crucial for cell volume regulation and have many other important roles, including tumor drug resistance and release of neurotransmitters. Although VRAC-mediated swelling-activated chloride currents (ICl,vol) have been studied for decades, exploration of the structure-function relationship of VRAC has become possible only after the recent discovery that VRACs are formed by differently composed heteromers of LRRC8 proteins. Inactivation of ICl,vol at positive potentials, a typical hallmark of VRACs, strongly varies between native cell types. Exploiting the large differences in inactivation between different LRRC8 heteromers, we now used chimeras assembled from isoforms LRRC8C and LRRC8E to uncover a highly conserved extracellular region preceding the second LRRC8 transmembrane domain as a major determinant of ICl,vol inactivation. Point mutations identified two amino acids (Lys-98 and Asp-100 in LRRC8A and equivalent residues in LRRC8C and -E), which upon charge reversal strongly altered the kinetics and voltage dependence of inactivation. Importantly, charge reversal at the first position also reduced the iodide > chloride permeability of ICl,vol This change in selectivity was stronger when both the obligatory LRRC8A subunit and the other co-expressed isoform (LRR8C or -E) carried such mutations. Hence, the C-terminal part of the first extracellular loop not only determines VRAC inactivation but might also participate in forming its outer pore. Inactivation of VRACs may involve a closure of the extracellular mouth of the permeation pathway.
Collapse
Affiliation(s)
- Florian Ullrich
- From the Leibniz-Institut für Molekulare Pharmakologie (FMP) and Max-Delbrück-Centrum für Molekulare Medizin (MDC), D-13125 Berlin, the Graduate Program, Freie Universität Berlin, D-14195 Berlin, and
| | - S Momsen Reincke
- From the Leibniz-Institut für Molekulare Pharmakologie (FMP) and Max-Delbrück-Centrum für Molekulare Medizin (MDC), D-13125 Berlin
| | - Felizia K Voss
- From the Leibniz-Institut für Molekulare Pharmakologie (FMP) and Max-Delbrück-Centrum für Molekulare Medizin (MDC), D-13125 Berlin
| | - Tobias Stauber
- From the Leibniz-Institut für Molekulare Pharmakologie (FMP) and Max-Delbrück-Centrum für Molekulare Medizin (MDC), D-13125 Berlin
| | - Thomas J Jentsch
- From the Leibniz-Institut für Molekulare Pharmakologie (FMP) and Max-Delbrück-Centrum für Molekulare Medizin (MDC), D-13125 Berlin, Neurocure, Charité Universitätsmedizin, D-10117 Berlin, Germany
| |
Collapse
|
48
|
Plotkin LI, Laird DW, Amedee J. Role of connexins and pannexins during ontogeny, regeneration, and pathologies of bone. BMC Cell Biol 2016; 17 Suppl 1:19. [PMID: 27230612 PMCID: PMC4896274 DOI: 10.1186/s12860-016-0088-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Electron micrographs revealed the presence of gap junctions in osteoblastic cells over 40 years ago. These intercellular channels formed from connexins are present in bone forming osteoblasts, bone resorbing osteoclasts, and osteocytes (mature osteoblasts embedded in the mineralized bone matrix). More recently, genetic and pharmacologic studies revealed the role of connexins, and in particular Cx43, in the differentiation and function of all bone types. Furthermore, mutations in the gene encoding Cx43 were found to be causally linked to oculodentodigital dysplasia, a condition that results in an abnormal skeleton. Pannexins, molecules with similar structure and single-membrane channel forming potential as connexins when organized as hemichannels, are also expressed in osteoblastic cells. The function of pannexins in bone and cartilage is beginning to be uncovered, but more research is needed to determine the role of pannexins in bone development, adult bone mass and skeletal homeostasis. We describe here the current knowledge on the role of connexins and pannexins on skeletal health and disease.
Collapse
Affiliation(s)
- Lilian I Plotkin
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA. .,Roudebush Veterans Administration Medical Center Indiana, Indianapolis, IN, 46202, USA.
| | - Dale W Laird
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, N6A-5C1, Canada
| | - Joelle Amedee
- INSERM U1026, Tissue Bioengineering, Université Bordeaux, Bordeaux, F-33076, France
| |
Collapse
|
49
|
Abstract
Pannexin (Panx) is a gene family encoding gap junction proteins in vertebrates. So far, three isoforms (Panx1, 2 and 3) have been identified. All of three Panx isoforms express in the cochlea with distinct expression patterns. Panx1 expresses in the cochlea extensively, including the spiral limbus, the organ of Corti, and the cochlear lateral wall, whereas Panx2 and Panx3 restrict to the basal cells of the stria vascularis in the lateral wall and the cochlear bony structure, respectively. However, there is no pannexin expression in auditory sensory hair cells. Recent studies demonstrated that like connexin gap junction gene, Panx1 deficiency causes hearing loss. Panx1 channels dominate ATP release in the cochlea. Deletion of Panx1 abolishes ATP release in the cochlea and reduces endocochlear potential (EP), auditory receptor current/potential, and active cochlear amplification. Panx1 deficiency in the cochlea also activates caspase-3 cell apoptotic pathway leading to cell degeneration. These new findings suggest that pannexins have a critical role in the cochlea in regard to hearing. However, detailed information about pannexin function in the cochlea and Panx mutation induced hearing loss still remain largely undetermined. Further studies are required.
Collapse
Affiliation(s)
- Hong-Bo Zhao
- Department of Otolaryngology, University of Kentucky Medical Center, 800 Rose Street, Lexington, KY, 40536, USA.
| |
Collapse
|
50
|
Loss of Panx1 Impairs Mammary Gland Development at Lactation: Implications for Breast Tumorigenesis. PLoS One 2016; 11:e0154162. [PMID: 27099931 PMCID: PMC4839729 DOI: 10.1371/journal.pone.0154162] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 04/08/2016] [Indexed: 12/03/2022] Open
Abstract
Pannexin1 (Panx1) subunits oligomerize to form large-pore channels between the intracellular and extracellular milieu that have been shown to regulate proliferation, differentiation and cell death mechanisms. These key cellular responses are ultimately necessary for normal tissue development and function but the role of Panx1 in development, differentiation and function in many tissues remains unexplored, including that of the breast. Panx1 was identified to be expressed in the mammary gland through western blot and immunofluorescent analysis and is dynamically upregulated during pregnancy and lactation. In order to evaluate the role of Panx1 in the context of mammary gland development and function, Panx1-/- mice were evaluated in comparison to wild-type mice in the mammary glands of virgin, lactating and involuting mice. Our results revealed that Panx1 ablation did not affect virgin or involuting mammary glands following histological and whole mount analysis. Panx1 was necessary for timely alveolar development during early lactation based on a decreased number of alveolar lumen following histological analysis and reduced proliferation following Ki67 immunofluorescent labelling. Importantly, the loss of Panx1 in lactating mammary glands did not overtly affect epithelial or secretory differentiation of the mammary gland suggesting that Panx1 is not critical in normal mammary gland function. In addition, PANX1 mRNA expression was correlated with negative clinical outcomes in patients with breast cancer using in silico arrays. Together, our results suggest that Panx1 is necessary for timely alveolar development following the transition from pregnancy to lactation, which may have implications extending to patients with breast cancer.
Collapse
|