1
|
Lucaciu SA, Leighton SE, Hauser A, Yee R, Laird DW. Diversity in connexin biology. J Biol Chem 2023; 299:105263. [PMID: 37734551 PMCID: PMC10598745 DOI: 10.1016/j.jbc.2023.105263] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 09/08/2023] [Accepted: 09/14/2023] [Indexed: 09/23/2023] Open
Abstract
Over 35 years ago the cell biology community was introduced to connexins as the subunit employed to assemble semicrystalline clusters of intercellular channels that had been well described morphologically as gap junctions. The decade that followed would see knowledge of the unexpectedly large 21-member human connexin family grow to reflect unique and overlapping expression patterns in all organ systems. While connexin biology initially focused on their role in constructing highly regulated intercellular channels, this was destined to change as discoveries revealed that connexin hemichannels at the cell surface had novel roles in many cell types, especially when considering connexin pathologies. Acceptance of connexins as having bifunctional channel properties was initially met with some resistance, which has given way in recent years to the premise that connexins have multifunctional properties. Depending on the connexin isoform and cell of origin, connexins have wide-ranging half-lives that vary from a couple of hours to the life expectancy of the cell. Diversity in connexin channel characteristics and molecular properties were further revealed by X-ray crystallography and single-particle cryo-EM. New avenues have seen connexins or connexin fragments playing roles in cell adhesion, tunneling nanotubes, extracellular vesicles, mitochondrial membranes, transcription regulation, and in other emerging cellular functions. These discoveries were largely linked to Cx43, which is prominent in most human organs. Here, we will review the evolution of knowledge on connexin expression in human adults and more recent evidence linking connexins to a highly diverse array of cellular functions.
Collapse
Affiliation(s)
- Sergiu A Lucaciu
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, Canada; Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada
| | - Stephanie E Leighton
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, Canada
| | - Alexandra Hauser
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, Canada
| | - Ryan Yee
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada
| | - Dale W Laird
- Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, Canada; Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada.
| |
Collapse
|
2
|
An L, Gao H, Zhong Y, Liu Y, Cao Y, Yi J, Huang X, Wen C, Tong R, Pan Z, Yan X, Liu M, Wang S, Wu H, Hu T. The potential roles of stress-induced phosphoprotein 1 and connexin 43 in rats with reperfusion arrhythmia. Immun Inflamm Dis 2023; 11:e852. [PMID: 37904692 PMCID: PMC10546868 DOI: 10.1002/iid3.852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 04/03/2023] [Accepted: 04/12/2023] [Indexed: 11/01/2023] Open
Abstract
OBJECTIVE Connexin 43 (Cx43) is a critical gene for maintaining myocardial homeostasis. Interestingly, Cx43 and stress-induced phosphoprotein 1 (STIP1) were recorded to be lowly expressed in ischemia/reperfusion (I/R). However, their impacts on reperfusion arrhythmia (RA) remain to be explored. Our study aimed to find out the related underlying mechanisms. METHODS After the establishment of an isolated heart model through Langendorff perfusion, the heart rate, conduction activation time, conduction velocity, and conduction direction of the left ventricle were evaluated, along with the apoptotic rate detection in the collected myocardial tissues. After the construction of a hypoxia/reoxygenation (H/R)-induced cellular model, cell apoptosis, intercellular communication, cell viability, and the content of reactive oxygen species, superoxide dismutase, malondialdehyde, and lactic dehydrogenase were measured. The expression of Cx43 and STIP1 was determined in both rat heart and cell models. The bindings of STIP3 and Cx43 to heat shock protein 90 (HSP90) and heat shock protein 70 (HSP70) were verified. RESULTS Relative to the corresponding controls, Cx43 and STIP1 were decreased in myocardial tissues of RA rats and H/R-stimulated H9C2 cells, where Cx43-binding HSP70 and HSP90 were respectively increased and decreased, and ubiquitination level of Cx43 was enhanced. STIP1 overexpression promoted protein expression of Cx43, intercellular communication, and cell viability, and reduced cell apoptosis and oxidative stress in H/R-stimulated H9C2 cells. CONCLUSION STIP1 promoted Cx43 expression to improve intercellular communication and reduce oxidative stress in H/R-stimulated H9C2 cells.
Collapse
Affiliation(s)
- Li An
- School of AnesthesiologyGuizhou Medical UniversityGuiyangGuizhouChina
- Department of AnaesthesiologyAffiliated Hospital of Guizhou Medical UniversityGuiyangGuizhouChina
- Translational Medicine Research CenterGuizhou Medical UniversityGuiyangGuizhouChina
| | - Hong Gao
- Department of AnesthesiologyGuizhou Hospital of The 1st Affiliated Hospital, Sun Yat‐sen UniversityGuiyangGuizhouChina
| | - Yi Zhong
- Department of AnaesthesiologyAffiliated Hospital of Guizhou Medical UniversityGuiyangGuizhouChina
| | - Yanqiu Liu
- Department of AnesthesiologyGuiyang Fourth People's HospitalGuiyangGuizhouChina
| | - Ying Cao
- Department of AnesthesiologyGuiyang Second People's HospitalGuiyangGuizhouChina
| | - Jing Yi
- Department of AnaesthesiologyAffiliated Hospital of Guizhou Medical UniversityGuiyangGuizhouChina
| | - Xiang Huang
- School of AnesthesiologyGuizhou Medical UniversityGuiyangGuizhouChina
| | - Chunlei Wen
- Department of AnesthesiologyChildren's Hospital of Guiyang Maternal and Child Health HospitalGuiyangGuizhouChina
| | - Rui Tong
- School of AnesthesiologyGuizhou Medical UniversityGuiyangGuizhouChina
| | - Zhijun Pan
- School of AnesthesiologyGuizhou Medical UniversityGuiyangGuizhouChina
| | - Xu Yan
- School of AnesthesiologyGuizhou Medical UniversityGuiyangGuizhouChina
| | - Meiyan Liu
- School of AnesthesiologyGuizhou Medical UniversityGuiyangGuizhouChina
| | - Shengzhao Wang
- School of AnesthesiologyGuizhou Medical UniversityGuiyangGuizhouChina
| | - Hao Wu
- School of AnesthesiologyGuizhou Medical UniversityGuiyangGuizhouChina
| | - Tingju Hu
- Department of AnaesthesiologyAffiliated Hospital of Guizhou Medical UniversityGuiyangGuizhouChina
| |
Collapse
|
3
|
Agrawal RR, Larrea D, Xu Y, Shi L, Zirpoli H, Cummins LG, Emmanuele V, Song D, Yun TD, Macaluso FP, Min W, Kernie SG, Deckelbaum RJ, Area-Gomez E. Alzheimer's-Associated Upregulation of Mitochondria-Associated ER Membranes After Traumatic Brain Injury. Cell Mol Neurobiol 2023; 43:2219-2241. [PMID: 36571634 PMCID: PMC10287820 DOI: 10.1007/s10571-022-01299-0] [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: 11/28/2021] [Accepted: 10/04/2022] [Indexed: 12/27/2022]
Abstract
Traumatic brain injury (TBI) can lead to neurodegenerative diseases such as Alzheimer's disease (AD) through mechanisms that remain incompletely characterized. Similar to AD, TBI models present with cellular metabolic alterations and modulated cleavage of amyloid precursor protein (APP). Specifically, AD and TBI tissues display increases in amyloid-β as well as its precursor, the APP C-terminal fragment of 99 a.a. (C99). Our recent data in cell models of AD indicate that C99, due to its affinity for cholesterol, induces the formation of transient lipid raft domains in the ER known as mitochondria-associated endoplasmic reticulum (ER) membranes ("MAM" domains). The formation of these domains recruits and activates specific lipid metabolic enzymes that regulate cellular cholesterol trafficking and sphingolipid turnover. Increased C99 levels in AD cell models promote MAM formation and significantly modulate cellular lipid homeostasis. Here, these phenotypes were recapitulated in the controlled cortical impact (CCI) model of TBI in adult mice. Specifically, the injured cortex and hippocampus displayed significant increases in C99 and MAM activity, as measured by phospholipid synthesis, sphingomyelinase activity and cholesterol turnover. In addition, our cell type-specific lipidomics analyses revealed significant changes in microglial lipid composition that are consistent with the observed alterations in MAM-resident enzymes. Altogether, we propose that alterations in the regulation of MAM and relevant lipid metabolic pathways could contribute to the epidemiological connection between TBI and AD.
Collapse
Affiliation(s)
- Rishi R Agrawal
- Institute of Human Nutrition, Columbia University Irving Medical Center, 630 W. 168th St., Presbyterian Hospital 15E-1512, New York, NY, 10032, USA.
- Denali Therapeutics Inc., 161 Oyster Point Blvd., South San Francisco, CA, 94080, USA.
| | - Delfina Larrea
- Department of Neurology, Neurological Institute, Columbia University Irving Medical Center, 710 W. 168th St., New York, NY, 10032, USA
| | - Yimeng Xu
- Biomarkers Core Laboratory, Department of Pathology and Cell Biology, Columbia University Irving Medical Center, 622 W. 168th St., Presbyterian Hospital 10-105, New York, NY, 10032, USA
| | - Lingyan Shi
- Department of Chemistry, Columbia University, 3000 Broadway, Havemeyer Hall, New York, NY, 10027, USA
- Shu Chien-Gene Lay Department of Bioengineering, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Hylde Zirpoli
- Institute of Human Nutrition, Columbia University Irving Medical Center, 630 W. 168th St., Presbyterian Hospital 15E-1512, New York, NY, 10032, USA
| | - Leslie G Cummins
- Analytical Imaging Facility, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY, 10461, USA
| | - Valentina Emmanuele
- Department of Neurology, Neurological Institute, Columbia University Irving Medical Center, 710 W. 168th St., New York, NY, 10032, USA
| | - Donghui Song
- Department of Chemistry, Columbia University, 3000 Broadway, Havemeyer Hall, New York, NY, 10027, USA
| | - Taekyung D Yun
- Department of Neurology, Neurological Institute, Columbia University Irving Medical Center, 710 W. 168th St., New York, NY, 10032, USA
| | - Frank P Macaluso
- Analytical Imaging Facility, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY, 10461, USA
| | - Wei Min
- Biomarkers Core Laboratory, Department of Pathology and Cell Biology, Columbia University Irving Medical Center, 622 W. 168th St., Presbyterian Hospital 10-105, New York, NY, 10032, USA
| | - Steven G Kernie
- Department of Neurology, Neurological Institute, Columbia University Irving Medical Center, 710 W. 168th St., New York, NY, 10032, USA
- Department of Pediatrics, Columbia University Irving Medical Center, 622 W. 168th St., Presbyterian Hospital 17, New York, NY, 10032, USA
| | - Richard J Deckelbaum
- Institute of Human Nutrition, Columbia University Irving Medical Center, 630 W. 168th St., Presbyterian Hospital 15E-1512, New York, NY, 10032, USA
- Department of Pediatrics, Columbia University Irving Medical Center, 622 W. 168th St., Presbyterian Hospital 17, New York, NY, 10032, USA
| | - Estela Area-Gomez
- Institute of Human Nutrition, Columbia University Irving Medical Center, 630 W. 168th St., Presbyterian Hospital 15E-1512, New York, NY, 10032, USA.
- Department of Neurology, Neurological Institute, Columbia University Irving Medical Center, 710 W. 168th St., New York, NY, 10032, USA.
- Centro de Investigaciones Biológicas Margarita Salas - CSIC, C. Ramiro de Maeztu, 9, 28040, Madrid, Spain.
| |
Collapse
|
4
|
An L, Gao H, Zhong Y, Liu Y, Cao Y, Yi J, Huang X, Wen C, Tong R, Pan Z, Yan X, Liu M, Wang S, Bai X, Wu H, Hu T. Molecular chaperones HSP40, HSP70, STIP1, and HSP90 are involved in stabilization of Cx43. Cytotechnology 2023; 75:207-217. [PMID: 37187948 PMCID: PMC10167082 DOI: 10.1007/s10616-023-00570-6] [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: 11/01/2022] [Accepted: 01/10/2023] [Indexed: 02/05/2023] Open
Abstract
To investigate the involvement of stress induced phosphoprotein 1 (STIP1), heat shock protein (HSP) 70, and HSP90 in ubiquitination of connexin 43 (Cx43) in rat H9c2 cardiomyocytes. Co-immunoprecipitation was used to detect protein-protein interactions and Cx43 ubiquitination. Immunofluorescence was used for protein co-localization. The protein binding, Cx43 protein expression, and Cx43 ubiquitination were reanalyzed in H9c2 cells with modified STIP1 and/or HSP90 expression. STIP1 bound to HSP70 and HSP90, and Cx43 bound to HSP40, HSP70, and HSP90 in normal H9c2 cardiomyocytes. Overexpression of STIP1 promoted the transition of Cx43-HSP70 to Cx43-HSP90 and inhibited Cx43 ubiquitination; knockdown of STIP1 resulted in the opposite effects. Inhibition of HSP90 counteracted the inhibitory effect of STIP1 overexpression on Cx43 ubiquitination. STIP1 suppresses Cx43 ubiquitination in H9c2 cardiomyocytes by promoting the transition of Cx43-HSP70 to Cx43-HSP90.
Collapse
Affiliation(s)
- Li An
- Guizhou Medical University, Guiyang, 550004 Guizhou People’s Republic of China
- Department of Anesthesiology, The Affiliated Hospital of Guizhou Medical University, No. 28 Guiyi St, Yunyan District, Guiyang, 550004 Guizhou People’s Republic of China
- Translational Medicine Research Center of Guizhou Medical University, Guiyang, 550004 Guizhou People’s Republic of China
| | - Hong Gao
- Department of Anesthesiology, The Affiliated Hospital of Guizhou Medical University, No. 28 Guiyi St, Yunyan District, Guiyang, 550004 Guizhou People’s Republic of China
| | - Yi Zhong
- Department of Anesthesiology, The Affiliated Hospital of Guizhou Medical University, No. 28 Guiyi St, Yunyan District, Guiyang, 550004 Guizhou People’s Republic of China
| | - Yanqiu Liu
- Department of Anesthesiology, Guiyang Fourth People’s Hospital, Guiyang, 550002 Guizhou People’s Republic of China
| | - Ying Cao
- School of Anesthesiology, Guizhou Medical University, Guiyang, 550004 Guizhou People’s Republic of China
- Guiyang Second People’s Hospital, Guiyang, 550001 Guizhou People’s Republic of China
| | - Jing Yi
- Department of Anesthesiology, The Affiliated Hospital of Guizhou Medical University, No. 28 Guiyi St, Yunyan District, Guiyang, 550004 Guizhou People’s Republic of China
| | - Xiang Huang
- School of Anesthesiology, Guizhou Medical University, Guiyang, 550004 Guizhou People’s Republic of China
| | - Chunlei Wen
- Children’s Hospital of Guiyang Maternal and Child Health Hospital, Guiyang, 550001 Guizhou People’s Republic of China
| | - Rui Tong
- School of Anesthesiology, Guizhou Medical University, Guiyang, 550004 Guizhou People’s Republic of China
| | - Zhijun Pan
- School of Anesthesiology, Guizhou Medical University, Guiyang, 550004 Guizhou People’s Republic of China
| | - Xu Yan
- School of Anesthesiology, Guizhou Medical University, Guiyang, 550004 Guizhou People’s Republic of China
| | - Meiyan Liu
- School of Anesthesiology, Guizhou Medical University, Guiyang, 550004 Guizhou People’s Republic of China
| | - Shengzhao Wang
- School of Anesthesiology, Guizhou Medical University, Guiyang, 550004 Guizhou People’s Republic of China
| | - Xue Bai
- School of Anesthesiology, Guizhou Medical University, Guiyang, 550004 Guizhou People’s Republic of China
| | - Hao Wu
- School of Anesthesiology, Guizhou Medical University, Guiyang, 550004 Guizhou People’s Republic of China
| | - Tingju Hu
- School of Anesthesiology, Guizhou Medical University, Guiyang, 550004 Guizhou People’s Republic of China
| |
Collapse
|
5
|
Cetin-Ferra S, Francis SC, Cooper AT, Neikirk K, Marshall AG, Hinton A, Murray SA. Mitochondrial Connexins and Mitochondrial Contact Sites with Gap Junction Structure. Int J Mol Sci 2023; 24:ijms24109036. [PMID: 37240383 DOI: 10.3390/ijms24109036] [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: 04/14/2023] [Revised: 05/16/2023] [Accepted: 05/16/2023] [Indexed: 05/28/2023] Open
Abstract
Mitochondria contain connexins, a family of proteins that is known to form gap junction channels. Connexins are synthesized in the endoplasmic reticulum and oligomerized in the Golgi to form hemichannels. Hemichannels from adjacent cells dock with one another to form gap junction channels that aggregate into plaques and allow cell-cell communication. Cell-cell communication was once thought to be the only function of connexins and their gap junction channels. In the mitochondria, however, connexins have been identified as monomers and assembled into hemichannels, thus questioning their role solely as cell-cell communication channels. Accordingly, mitochondrial connexins have been suggested to play critical roles in the regulation of mitochondrial functions, including potassium fluxes and respiration. However, while much is known about plasma membrane gap junction channel connexins, the presence and function of mitochondrial connexins remain poorly understood. In this review, the presence and role of mitochondrial connexins and mitochondrial/connexin-containing structure contact sites will be discussed. An understanding of the significance of mitochondrial connexins and their connexin contact sites is essential to our knowledge of connexins' functions in normal and pathological conditions, and this information may aid in the development of therapeutic interventions in diseases linked to mitochondria.
Collapse
Affiliation(s)
- Selma Cetin-Ferra
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Sharon C Francis
- Department of Physiology, Morehouse School of Medicine, Atlanta, GA 30310, USA
| | - Anthonya T Cooper
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Kit Neikirk
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
- Department of Biology, University of Hawaii, Hilo, HI 96720, USA
| | - Andrea G Marshall
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - Antentor Hinton
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - Sandra A Murray
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| |
Collapse
|
6
|
Zhou Q, Wang Y, Lu Z, He C, Li L, You M, Wang L, Cao T, Zhao Y, Li Q, Mou A, Shu W, He H, Zhao Z, Liu D, Zhu Z, Gao P, Yan Z. Cx43 acts as a mitochondrial calcium regulator that promotes obesity by inducing the polarization of macrophages in adipose tissue. Cell Signal 2023; 105:110606. [PMID: 36681290 DOI: 10.1016/j.cellsig.2023.110606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 01/12/2023] [Accepted: 01/16/2023] [Indexed: 01/21/2023]
Abstract
Metabolic reprogramming of macrophages initiates the polarization of pro-inflammatory macrophages that exacerbates adipocyte dysfunction and obesity. The imbalance of mitochondrial Ca2+ homeostasis impairs mitochondrial function and promotes inflammation. Connexin 43 (Cx43), a ubiquitous gap junction protein, has been demonstrated to regulate intracellular Ca2+ homeostasis. Here we explored whether macrophage Cx43 affects the obesity process by regulating the polarization of macrophage. HFD treatment induced obesity and exacerbated macrophages infiltration with upregulation of macrophages Cx43. Macrophage-specific knockout of Cx43 reduced HFD-induced obesity by alleviating inflammation in adipose tissue, with less pro-inflammatory M1 macrophage infiltration. Consistently, inhibition or knockdown of Cx43 improved palmitic acid (PA) induced mitochondrial dysfunction, as indicated by improved oxidative phosphorylation (OXPHOS), reduced formation of mitochondria-associated membranes (MAM) and mitochondrial Ca2+ overload. Mechanistically, Cx43 interacted with the mitochondrial Ca2+ uniporter (MCU) and knockdown of Cx43 alleviated PA-induced succinate dehydrogenase (SDH) oxidation by lowering MCU-mediated mitochondrial Ca2+ uptake, which then, promoting the polarization of pro-inflammatory M1 macrophages. Thus, this study identified Cx43 as a mitochondrial Ca2+ regulator that aggravates obesity via promoting macrophages polarized to M1 pro-inflammatory phenotype and suggests that Cx43 might be a promising therapeutic target antagonizing obesity.
Collapse
Affiliation(s)
- Qing Zhou
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China
| | - Yuyan Wang
- School of Medicine, Chongqing University, Chongqing, China
| | - Zongshi Lu
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China
| | - Chengkang He
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China
| | - Li Li
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China
| | - Mei You
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China
| | - Lijuan Wang
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China
| | - Tingbing Cao
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China
| | - Yu Zhao
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China
| | - Qiang Li
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China
| | - Aidi Mou
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China
| | - Wentao Shu
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China
| | - Hongbo He
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China
| | - Zhigang Zhao
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China
| | - Daoyan Liu
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China
| | - Zhiming Zhu
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China.
| | - Peng Gao
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China.
| | - Zhencheng Yan
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China.
| |
Collapse
|
7
|
Mitochondrial connexin43 and mitochondrial K ATP channels modulate triggered arrhythmias in mouse ventricular muscle. Pflugers Arch 2023; 475:477-488. [PMID: 36707457 DOI: 10.1007/s00424-023-02789-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 12/21/2022] [Accepted: 01/18/2023] [Indexed: 01/29/2023]
Abstract
Connexin43 (Cx43) exits as hemichannels in the inner mitochondrial membrane. We examined how mitochondrial Cx43 and mitochondrial KATP channels affect the occurrence of triggered arrhythmias. To generate cardiac-specific Cx43-deficient (cCx43-/-) mice, Cx43flox/flox mice were crossed with α-MHC (Myh6)-cre+/- mice. The resulting offspring, Cx43flox/flox/Myh6-cre+/- mice (cCx43-/- mice) and their littermates (cCx43+/+ mice), were used. Trabeculae were dissected from the right ventricles of mouse hearts. Cardiomyocytes were enzymatically isolated from the ventricles of mouse hearts. Force was measured with a strain gauge in trabeculae (22°C). To assess arrhythmia susceptibility, the minimal extracellular Ca2+ concentration ([Ca2+]o,min), at which arrhythmias were induced by electrical stimulation, was determined in trabeculae. ROS production was estimated with 2',7'-dichlorofluorescein (DCF), mitochondrial membrane potential with tetramethylrhodamine methyl ester (TMRM), and Ca2+ spark frequency with fluo-4 and confocal microscopy in cardiomyocytes. ROS production within the mitochondria was estimated with MitoSoxRed and mitochondrial Ca2+ with rhod-2 in trabeculae. Diazoxide was used to activate mitochondrial KATP. Most of cCx43-/- mice died suddenly within 8 weeks. Cx43 was present in the inner mitochondrial membrane in cCx43+/+ mice but not in cCx43-/- mice. In cCx43-/- mice, the [Ca2+]o,min was lower, and Ca2+ spark frequency, the slope of DCF fluorescence intensity, MitoSoxRed fluorescence, and rhod-2 fluorescence were higher. TMRM fluorescence was more decreased in cCx43-/- mice. Most of these changes were suppressed by diazoxide. In addition, in cCx43-/- mice, antioxidant peptide SS-31 and N-acetyl-L-cysteine increased the [Ca2+]o,min. These results suggest that Cx43 deficiency activates Ca2+ leak from the SR, probably due to depolarization of mitochondrial membrane potential, an increase in mitochondrial Ca2+, and an increase in ROS production, thereby causing triggered arrhythmias, and that Cx43 hemichannel deficiency may be compensated by activation of mitochondrial KATP channels in mouse hearts.
Collapse
|
8
|
Schulz R, Schlüter KD. Importance of Mitochondria in Cardiac Pathologies: Focus on Uncoupling Proteins and Monoamine Oxidases. Int J Mol Sci 2023; 24:ijms24076459. [PMID: 37047436 PMCID: PMC10095304 DOI: 10.3390/ijms24076459] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Revised: 03/22/2023] [Accepted: 03/28/2023] [Indexed: 04/03/2023] Open
Abstract
On the one hand, reactive oxygen species (ROS) are involved in the onset and progression of a wide array of diseases. On the other hand, these are a part of signaling pathways related to cell metabolism, growth and survival. While ROS are produced at various cellular sites, in cardiomyocytes the largest amount of ROS is generated by mitochondria. Apart from the electron transport chain and various other proteins, uncoupling protein (UCP) and monoamine oxidases (MAO) have been proposed to modify mitochondrial ROS formation. Here, we review the recent information on UCP and MAO in cardiac injuries induced by ischemia-reperfusion (I/R) as well as protection from I/R and heart failure secondary to I/R injury or pressure overload. The current data in the literature suggest that I/R will preferentially upregulate UCP2 in cardiac tissue but not UCP3. Studies addressing the consequences of such induction are currently inconclusive because the precise function of UCP2 in cardiac tissue is not well understood, and tissue- and species-specific aspects complicate the situation. In general, UCP2 may reduce oxidative stress by mild uncoupling and both UCP2 and UCP3 affect substrate utilization in cardiac tissue, thereby modifying post-ischemic remodeling. MAOs are important for the physiological regulation of substrate concentrations. Upon increased expression and or activity of MAOs, however, the increased production of ROS and reactive aldehydes contribute to cardiac alterations such as hypertrophy, inflammation, irreversible cardiomyocyte injury, and failure.
Collapse
|
9
|
Ferdinandy P, Andreadou I, Baxter GF, Bøtker HE, Davidson SM, Dobrev D, Gersh BJ, Heusch G, Lecour S, Ruiz-Meana M, Zuurbier CJ, Hausenloy DJ, Schulz R. Interaction of Cardiovascular Nonmodifiable Risk Factors, Comorbidities and Comedications With Ischemia/Reperfusion Injury and Cardioprotection by Pharmacological Treatments and Ischemic Conditioning. Pharmacol Rev 2023; 75:159-216. [PMID: 36753049 PMCID: PMC9832381 DOI: 10.1124/pharmrev.121.000348] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 08/07/2022] [Accepted: 09/12/2022] [Indexed: 12/13/2022] Open
Abstract
Preconditioning, postconditioning, and remote conditioning of the myocardium enhance the ability of the heart to withstand a prolonged ischemia/reperfusion insult and the potential to provide novel therapeutic paradigms for cardioprotection. While many signaling pathways leading to endogenous cardioprotection have been elucidated in experimental studies over the past 30 years, no cardioprotective drug is on the market yet for that indication. One likely major reason for this failure to translate cardioprotection into patient benefit is the lack of rigorous and systematic preclinical evaluation of promising cardioprotective therapies prior to their clinical evaluation, since ischemic heart disease in humans is a complex disorder caused by or associated with cardiovascular risk factors and comorbidities. These risk factors and comorbidities induce fundamental alterations in cellular signaling cascades that affect the development of ischemia/reperfusion injury and responses to cardioprotective interventions. Moreover, some of the medications used to treat these comorbidities may impact on cardioprotection by again modifying cellular signaling pathways. The aim of this article is to review the recent evidence that cardiovascular risk factors as well as comorbidities and their medications may modify the response to cardioprotective interventions. We emphasize the critical need for taking into account the presence of cardiovascular risk factors as well as comorbidities and their concomitant medications when designing preclinical studies for the identification and validation of cardioprotective drug targets and clinical studies. This will hopefully maximize the success rate of developing rational approaches to effective cardioprotective therapies for the majority of patients with multiple comorbidities. SIGNIFICANCE STATEMENT: Ischemic heart disease is a major cause of mortality; however, there are still no cardioprotective drugs on the market. Most studies on cardioprotection have been undertaken in animal models of ischemia/reperfusion in the absence of comorbidities; however, ischemic heart disease develops with other systemic disorders (e.g., hypertension, hyperlipidemia, diabetes, atherosclerosis). Here we focus on the preclinical and clinical evidence showing how these comorbidities and their routine medications affect ischemia/reperfusion injury and interfere with cardioprotective strategies.
Collapse
Affiliation(s)
- Péter Ferdinandy
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Laboratory of Pharmacology, Faculty of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece (I.A.); Division of Pharmacology, Cardiff School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK (G.F.B.); Department of Cardiology, Aarhus University Hospital, Aarhus N, Denmark (H.E.B.); The Hatter Cardiovascular Institute, University College London, London, UK (S.M.D.); Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.); Department of Medicine, Montreal Heart Institute and Université de Montréal, Montréal, Québec, Canada (D.D.); Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas (D.D.); Department of Cardiovascular Medicine, Mayo Clinic College of Medicine and Science, Rochester, Minnesota (B.J.G.); Institute for Pathophysiology, West German Heart and Vascular Center, University of Essen Medical School, Essen, Germany (G.H.); Cape Heart Institute and Hatter Institute for Cardiovascular Research in Africa, Department of Medicine, University of Cape Town, Cape Town, South Africa (S.L.); Cardiovascular Diseases Research Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, Vall d'Hebron Barcelona Hospital Campus, Spain (M.R-M.); Laboratory of Experimental Intensive Care Anesthesiology, Department Anesthesiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands (C.J.Z.); Cardiovascular & Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore (D.J.H.); National Heart Research Institute Singapore, National Heart Centre, Singapore (D.J.H.); Yong Loo Lin School of Medicine, National University Singapore, Singapore (D.J.H.); Cardiovascular Research Center, College of Medical and Health Sciences, Asia University, Taiwan (D.J.H.); and Institute of Physiology, Justus-Liebig University, Giessen, Germany (R.S.)
| | - Ioanna Andreadou
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Laboratory of Pharmacology, Faculty of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece (I.A.); Division of Pharmacology, Cardiff School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK (G.F.B.); Department of Cardiology, Aarhus University Hospital, Aarhus N, Denmark (H.E.B.); The Hatter Cardiovascular Institute, University College London, London, UK (S.M.D.); Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.); Department of Medicine, Montreal Heart Institute and Université de Montréal, Montréal, Québec, Canada (D.D.); Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas (D.D.); Department of Cardiovascular Medicine, Mayo Clinic College of Medicine and Science, Rochester, Minnesota (B.J.G.); Institute for Pathophysiology, West German Heart and Vascular Center, University of Essen Medical School, Essen, Germany (G.H.); Cape Heart Institute and Hatter Institute for Cardiovascular Research in Africa, Department of Medicine, University of Cape Town, Cape Town, South Africa (S.L.); Cardiovascular Diseases Research Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, Vall d'Hebron Barcelona Hospital Campus, Spain (M.R-M.); Laboratory of Experimental Intensive Care Anesthesiology, Department Anesthesiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands (C.J.Z.); Cardiovascular & Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore (D.J.H.); National Heart Research Institute Singapore, National Heart Centre, Singapore (D.J.H.); Yong Loo Lin School of Medicine, National University Singapore, Singapore (D.J.H.); Cardiovascular Research Center, College of Medical and Health Sciences, Asia University, Taiwan (D.J.H.); and Institute of Physiology, Justus-Liebig University, Giessen, Germany (R.S.)
| | - Gary F Baxter
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Laboratory of Pharmacology, Faculty of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece (I.A.); Division of Pharmacology, Cardiff School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK (G.F.B.); Department of Cardiology, Aarhus University Hospital, Aarhus N, Denmark (H.E.B.); The Hatter Cardiovascular Institute, University College London, London, UK (S.M.D.); Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.); Department of Medicine, Montreal Heart Institute and Université de Montréal, Montréal, Québec, Canada (D.D.); Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas (D.D.); Department of Cardiovascular Medicine, Mayo Clinic College of Medicine and Science, Rochester, Minnesota (B.J.G.); Institute for Pathophysiology, West German Heart and Vascular Center, University of Essen Medical School, Essen, Germany (G.H.); Cape Heart Institute and Hatter Institute for Cardiovascular Research in Africa, Department of Medicine, University of Cape Town, Cape Town, South Africa (S.L.); Cardiovascular Diseases Research Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, Vall d'Hebron Barcelona Hospital Campus, Spain (M.R-M.); Laboratory of Experimental Intensive Care Anesthesiology, Department Anesthesiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands (C.J.Z.); Cardiovascular & Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore (D.J.H.); National Heart Research Institute Singapore, National Heart Centre, Singapore (D.J.H.); Yong Loo Lin School of Medicine, National University Singapore, Singapore (D.J.H.); Cardiovascular Research Center, College of Medical and Health Sciences, Asia University, Taiwan (D.J.H.); and Institute of Physiology, Justus-Liebig University, Giessen, Germany (R.S.)
| | - Hans Erik Bøtker
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Laboratory of Pharmacology, Faculty of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece (I.A.); Division of Pharmacology, Cardiff School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK (G.F.B.); Department of Cardiology, Aarhus University Hospital, Aarhus N, Denmark (H.E.B.); The Hatter Cardiovascular Institute, University College London, London, UK (S.M.D.); Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.); Department of Medicine, Montreal Heart Institute and Université de Montréal, Montréal, Québec, Canada (D.D.); Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas (D.D.); Department of Cardiovascular Medicine, Mayo Clinic College of Medicine and Science, Rochester, Minnesota (B.J.G.); Institute for Pathophysiology, West German Heart and Vascular Center, University of Essen Medical School, Essen, Germany (G.H.); Cape Heart Institute and Hatter Institute for Cardiovascular Research in Africa, Department of Medicine, University of Cape Town, Cape Town, South Africa (S.L.); Cardiovascular Diseases Research Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, Vall d'Hebron Barcelona Hospital Campus, Spain (M.R-M.); Laboratory of Experimental Intensive Care Anesthesiology, Department Anesthesiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands (C.J.Z.); Cardiovascular & Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore (D.J.H.); National Heart Research Institute Singapore, National Heart Centre, Singapore (D.J.H.); Yong Loo Lin School of Medicine, National University Singapore, Singapore (D.J.H.); Cardiovascular Research Center, College of Medical and Health Sciences, Asia University, Taiwan (D.J.H.); and Institute of Physiology, Justus-Liebig University, Giessen, Germany (R.S.)
| | - Sean M Davidson
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Laboratory of Pharmacology, Faculty of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece (I.A.); Division of Pharmacology, Cardiff School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK (G.F.B.); Department of Cardiology, Aarhus University Hospital, Aarhus N, Denmark (H.E.B.); The Hatter Cardiovascular Institute, University College London, London, UK (S.M.D.); Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.); Department of Medicine, Montreal Heart Institute and Université de Montréal, Montréal, Québec, Canada (D.D.); Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas (D.D.); Department of Cardiovascular Medicine, Mayo Clinic College of Medicine and Science, Rochester, Minnesota (B.J.G.); Institute for Pathophysiology, West German Heart and Vascular Center, University of Essen Medical School, Essen, Germany (G.H.); Cape Heart Institute and Hatter Institute for Cardiovascular Research in Africa, Department of Medicine, University of Cape Town, Cape Town, South Africa (S.L.); Cardiovascular Diseases Research Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, Vall d'Hebron Barcelona Hospital Campus, Spain (M.R-M.); Laboratory of Experimental Intensive Care Anesthesiology, Department Anesthesiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands (C.J.Z.); Cardiovascular & Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore (D.J.H.); National Heart Research Institute Singapore, National Heart Centre, Singapore (D.J.H.); Yong Loo Lin School of Medicine, National University Singapore, Singapore (D.J.H.); Cardiovascular Research Center, College of Medical and Health Sciences, Asia University, Taiwan (D.J.H.); and Institute of Physiology, Justus-Liebig University, Giessen, Germany (R.S.)
| | - Dobromir Dobrev
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Laboratory of Pharmacology, Faculty of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece (I.A.); Division of Pharmacology, Cardiff School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK (G.F.B.); Department of Cardiology, Aarhus University Hospital, Aarhus N, Denmark (H.E.B.); The Hatter Cardiovascular Institute, University College London, London, UK (S.M.D.); Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.); Department of Medicine, Montreal Heart Institute and Université de Montréal, Montréal, Québec, Canada (D.D.); Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas (D.D.); Department of Cardiovascular Medicine, Mayo Clinic College of Medicine and Science, Rochester, Minnesota (B.J.G.); Institute for Pathophysiology, West German Heart and Vascular Center, University of Essen Medical School, Essen, Germany (G.H.); Cape Heart Institute and Hatter Institute for Cardiovascular Research in Africa, Department of Medicine, University of Cape Town, Cape Town, South Africa (S.L.); Cardiovascular Diseases Research Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, Vall d'Hebron Barcelona Hospital Campus, Spain (M.R-M.); Laboratory of Experimental Intensive Care Anesthesiology, Department Anesthesiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands (C.J.Z.); Cardiovascular & Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore (D.J.H.); National Heart Research Institute Singapore, National Heart Centre, Singapore (D.J.H.); Yong Loo Lin School of Medicine, National University Singapore, Singapore (D.J.H.); Cardiovascular Research Center, College of Medical and Health Sciences, Asia University, Taiwan (D.J.H.); and Institute of Physiology, Justus-Liebig University, Giessen, Germany (R.S.)
| | - Bernard J Gersh
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Laboratory of Pharmacology, Faculty of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece (I.A.); Division of Pharmacology, Cardiff School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK (G.F.B.); Department of Cardiology, Aarhus University Hospital, Aarhus N, Denmark (H.E.B.); The Hatter Cardiovascular Institute, University College London, London, UK (S.M.D.); Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.); Department of Medicine, Montreal Heart Institute and Université de Montréal, Montréal, Québec, Canada (D.D.); Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas (D.D.); Department of Cardiovascular Medicine, Mayo Clinic College of Medicine and Science, Rochester, Minnesota (B.J.G.); Institute for Pathophysiology, West German Heart and Vascular Center, University of Essen Medical School, Essen, Germany (G.H.); Cape Heart Institute and Hatter Institute for Cardiovascular Research in Africa, Department of Medicine, University of Cape Town, Cape Town, South Africa (S.L.); Cardiovascular Diseases Research Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, Vall d'Hebron Barcelona Hospital Campus, Spain (M.R-M.); Laboratory of Experimental Intensive Care Anesthesiology, Department Anesthesiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands (C.J.Z.); Cardiovascular & Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore (D.J.H.); National Heart Research Institute Singapore, National Heart Centre, Singapore (D.J.H.); Yong Loo Lin School of Medicine, National University Singapore, Singapore (D.J.H.); Cardiovascular Research Center, College of Medical and Health Sciences, Asia University, Taiwan (D.J.H.); and Institute of Physiology, Justus-Liebig University, Giessen, Germany (R.S.)
| | - Gerd Heusch
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Laboratory of Pharmacology, Faculty of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece (I.A.); Division of Pharmacology, Cardiff School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK (G.F.B.); Department of Cardiology, Aarhus University Hospital, Aarhus N, Denmark (H.E.B.); The Hatter Cardiovascular Institute, University College London, London, UK (S.M.D.); Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.); Department of Medicine, Montreal Heart Institute and Université de Montréal, Montréal, Québec, Canada (D.D.); Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas (D.D.); Department of Cardiovascular Medicine, Mayo Clinic College of Medicine and Science, Rochester, Minnesota (B.J.G.); Institute for Pathophysiology, West German Heart and Vascular Center, University of Essen Medical School, Essen, Germany (G.H.); Cape Heart Institute and Hatter Institute for Cardiovascular Research in Africa, Department of Medicine, University of Cape Town, Cape Town, South Africa (S.L.); Cardiovascular Diseases Research Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, Vall d'Hebron Barcelona Hospital Campus, Spain (M.R-M.); Laboratory of Experimental Intensive Care Anesthesiology, Department Anesthesiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands (C.J.Z.); Cardiovascular & Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore (D.J.H.); National Heart Research Institute Singapore, National Heart Centre, Singapore (D.J.H.); Yong Loo Lin School of Medicine, National University Singapore, Singapore (D.J.H.); Cardiovascular Research Center, College of Medical and Health Sciences, Asia University, Taiwan (D.J.H.); and Institute of Physiology, Justus-Liebig University, Giessen, Germany (R.S.)
| | - Sandrine Lecour
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Laboratory of Pharmacology, Faculty of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece (I.A.); Division of Pharmacology, Cardiff School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK (G.F.B.); Department of Cardiology, Aarhus University Hospital, Aarhus N, Denmark (H.E.B.); The Hatter Cardiovascular Institute, University College London, London, UK (S.M.D.); Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.); Department of Medicine, Montreal Heart Institute and Université de Montréal, Montréal, Québec, Canada (D.D.); Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas (D.D.); Department of Cardiovascular Medicine, Mayo Clinic College of Medicine and Science, Rochester, Minnesota (B.J.G.); Institute for Pathophysiology, West German Heart and Vascular Center, University of Essen Medical School, Essen, Germany (G.H.); Cape Heart Institute and Hatter Institute for Cardiovascular Research in Africa, Department of Medicine, University of Cape Town, Cape Town, South Africa (S.L.); Cardiovascular Diseases Research Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, Vall d'Hebron Barcelona Hospital Campus, Spain (M.R-M.); Laboratory of Experimental Intensive Care Anesthesiology, Department Anesthesiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands (C.J.Z.); Cardiovascular & Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore (D.J.H.); National Heart Research Institute Singapore, National Heart Centre, Singapore (D.J.H.); Yong Loo Lin School of Medicine, National University Singapore, Singapore (D.J.H.); Cardiovascular Research Center, College of Medical and Health Sciences, Asia University, Taiwan (D.J.H.); and Institute of Physiology, Justus-Liebig University, Giessen, Germany (R.S.)
| | - Marisol Ruiz-Meana
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Laboratory of Pharmacology, Faculty of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece (I.A.); Division of Pharmacology, Cardiff School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK (G.F.B.); Department of Cardiology, Aarhus University Hospital, Aarhus N, Denmark (H.E.B.); The Hatter Cardiovascular Institute, University College London, London, UK (S.M.D.); Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.); Department of Medicine, Montreal Heart Institute and Université de Montréal, Montréal, Québec, Canada (D.D.); Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas (D.D.); Department of Cardiovascular Medicine, Mayo Clinic College of Medicine and Science, Rochester, Minnesota (B.J.G.); Institute for Pathophysiology, West German Heart and Vascular Center, University of Essen Medical School, Essen, Germany (G.H.); Cape Heart Institute and Hatter Institute for Cardiovascular Research in Africa, Department of Medicine, University of Cape Town, Cape Town, South Africa (S.L.); Cardiovascular Diseases Research Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, Vall d'Hebron Barcelona Hospital Campus, Spain (M.R-M.); Laboratory of Experimental Intensive Care Anesthesiology, Department Anesthesiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands (C.J.Z.); Cardiovascular & Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore (D.J.H.); National Heart Research Institute Singapore, National Heart Centre, Singapore (D.J.H.); Yong Loo Lin School of Medicine, National University Singapore, Singapore (D.J.H.); Cardiovascular Research Center, College of Medical and Health Sciences, Asia University, Taiwan (D.J.H.); and Institute of Physiology, Justus-Liebig University, Giessen, Germany (R.S.)
| | - Coert J Zuurbier
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Laboratory of Pharmacology, Faculty of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece (I.A.); Division of Pharmacology, Cardiff School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK (G.F.B.); Department of Cardiology, Aarhus University Hospital, Aarhus N, Denmark (H.E.B.); The Hatter Cardiovascular Institute, University College London, London, UK (S.M.D.); Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.); Department of Medicine, Montreal Heart Institute and Université de Montréal, Montréal, Québec, Canada (D.D.); Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas (D.D.); Department of Cardiovascular Medicine, Mayo Clinic College of Medicine and Science, Rochester, Minnesota (B.J.G.); Institute for Pathophysiology, West German Heart and Vascular Center, University of Essen Medical School, Essen, Germany (G.H.); Cape Heart Institute and Hatter Institute for Cardiovascular Research in Africa, Department of Medicine, University of Cape Town, Cape Town, South Africa (S.L.); Cardiovascular Diseases Research Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, Vall d'Hebron Barcelona Hospital Campus, Spain (M.R-M.); Laboratory of Experimental Intensive Care Anesthesiology, Department Anesthesiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands (C.J.Z.); Cardiovascular & Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore (D.J.H.); National Heart Research Institute Singapore, National Heart Centre, Singapore (D.J.H.); Yong Loo Lin School of Medicine, National University Singapore, Singapore (D.J.H.); Cardiovascular Research Center, College of Medical and Health Sciences, Asia University, Taiwan (D.J.H.); and Institute of Physiology, Justus-Liebig University, Giessen, Germany (R.S.)
| | - Derek J Hausenloy
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Laboratory of Pharmacology, Faculty of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece (I.A.); Division of Pharmacology, Cardiff School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK (G.F.B.); Department of Cardiology, Aarhus University Hospital, Aarhus N, Denmark (H.E.B.); The Hatter Cardiovascular Institute, University College London, London, UK (S.M.D.); Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.); Department of Medicine, Montreal Heart Institute and Université de Montréal, Montréal, Québec, Canada (D.D.); Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas (D.D.); Department of Cardiovascular Medicine, Mayo Clinic College of Medicine and Science, Rochester, Minnesota (B.J.G.); Institute for Pathophysiology, West German Heart and Vascular Center, University of Essen Medical School, Essen, Germany (G.H.); Cape Heart Institute and Hatter Institute for Cardiovascular Research in Africa, Department of Medicine, University of Cape Town, Cape Town, South Africa (S.L.); Cardiovascular Diseases Research Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, Vall d'Hebron Barcelona Hospital Campus, Spain (M.R-M.); Laboratory of Experimental Intensive Care Anesthesiology, Department Anesthesiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands (C.J.Z.); Cardiovascular & Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore (D.J.H.); National Heart Research Institute Singapore, National Heart Centre, Singapore (D.J.H.); Yong Loo Lin School of Medicine, National University Singapore, Singapore (D.J.H.); Cardiovascular Research Center, College of Medical and Health Sciences, Asia University, Taiwan (D.J.H.); and Institute of Physiology, Justus-Liebig University, Giessen, Germany (R.S.)
| | - Rainer Schulz
- Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, Hungary (P.F.); Pharmahungary Group, Szeged, Hungary (P.F.); Laboratory of Pharmacology, Faculty of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece (I.A.); Division of Pharmacology, Cardiff School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK (G.F.B.); Department of Cardiology, Aarhus University Hospital, Aarhus N, Denmark (H.E.B.); The Hatter Cardiovascular Institute, University College London, London, UK (S.M.D.); Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.); Department of Medicine, Montreal Heart Institute and Université de Montréal, Montréal, Québec, Canada (D.D.); Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas (D.D.); Department of Cardiovascular Medicine, Mayo Clinic College of Medicine and Science, Rochester, Minnesota (B.J.G.); Institute for Pathophysiology, West German Heart and Vascular Center, University of Essen Medical School, Essen, Germany (G.H.); Cape Heart Institute and Hatter Institute for Cardiovascular Research in Africa, Department of Medicine, University of Cape Town, Cape Town, South Africa (S.L.); Cardiovascular Diseases Research Group, Vall d'Hebron Institut de Recerca (VHIR), Vall d'Hebron Hospital Universitari, Vall d'Hebron Barcelona Hospital Campus, Spain (M.R-M.); Laboratory of Experimental Intensive Care Anesthesiology, Department Anesthesiology, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands (C.J.Z.); Cardiovascular & Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore (D.J.H.); National Heart Research Institute Singapore, National Heart Centre, Singapore (D.J.H.); Yong Loo Lin School of Medicine, National University Singapore, Singapore (D.J.H.); Cardiovascular Research Center, College of Medical and Health Sciences, Asia University, Taiwan (D.J.H.); and Institute of Physiology, Justus-Liebig University, Giessen, Germany (R.S.)
| |
Collapse
|
10
|
Whisenant CC, Shaw RM. Internal translation of Gja1 (Connexin43) to produce GJA1-20k: Implications for arrhythmia and ischemic-preconditioning. Front Physiol 2022; 13:1058954. [PMID: 36569758 PMCID: PMC9768480 DOI: 10.3389/fphys.2022.1058954] [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: 09/30/2022] [Accepted: 11/17/2022] [Indexed: 12/12/2022] Open
Abstract
Internal translation is a form of post-translation modification as it produces different proteins from one mRNA molecule by beginning translation at a methionine coding triplet downstream of the first methionine. Internal translation can eliminate domains of proteins that otherwise restrict movement or activity, thereby creating profound functional diversity. Connexin43 (Cx43), encoded by the gene Gja1, is the main gap junction protein necessary for propagating action potentials between adjacent cardiomyocytes. Gja1 can be internally translated to produce a peptide 20 kD in length named GJA1-20k. This review focuses on the role of GJA1-20k in maintaining cardiac electrical rhythm as well as in ischemic preconditioning (IPC). Connexin43 is the only ion channel we are aware that has been reported to be subject to internal translation. We expect many other ion channels also undergo internal translation. The exploration of post-translational modification of ion channels, and in particular of internal translation, has the potential to greatly increase our understanding of both canonical and non-canonical ion channel biology.
Collapse
|
11
|
Boengler K, Leybaert L, Ruiz-Meana M, Schulz R. Connexin 43 in Mitochondria: What Do We Really Know About Its Function? Front Physiol 2022; 13:928934. [PMID: 35860665 PMCID: PMC9289461 DOI: 10.3389/fphys.2022.928934] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 05/26/2022] [Indexed: 01/04/2023] Open
Abstract
Connexins are known for their ability to mediate cell-cell communication via gap junctions and also form hemichannels that pass ions and molecules over the plasma membrane when open. Connexins have also been detected within mitochondria, with mitochondrial connexin 43 (Cx43) being the best studied to date. In this review, we discuss evidence for Cx43 presence in mitochondria of cell lines, primary cells and organs and summarize data on its localization, import and phosphorylation status. We further highlight the influence of Cx43 on mitochondrial function in terms of respiration, opening of the mitochondrial permeability transition pore and formation of reactive oxygen species, and also address the presence of a truncated form of Cx43 termed Gja1-20k. Finally, the role of mitochondrial Cx43 in pathological conditions, particularly in the heart, is discussed.
Collapse
Affiliation(s)
- Kerstin Boengler
- Institute of Physiology, Justus-Liebig University, Giessen, Germany
| | - Luc Leybaert
- Department of Basic and Applied Medical Sciences—Physiology Group, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Marisol Ruiz-Meana
- Cardiovascular Diseases Research Group, Vall d’Hebron Institut de Recerca (VHIR), Vall d’Hebron Hospital Universitari, Barcelona, Spain
| | - Rainer Schulz
- Institute of Physiology, Justus-Liebig University, Giessen, Germany
- *Correspondence: Rainer Schulz,
| |
Collapse
|
12
|
Shimura D, Shaw RM. GJA1-20k and Mitochondrial Dynamics. Front Physiol 2022; 13:867358. [PMID: 35399255 PMCID: PMC8983841 DOI: 10.3389/fphys.2022.867358] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 03/08/2022] [Indexed: 01/07/2023] Open
Abstract
Connexin 43 (Cx43) is the primary gap junction protein of mammalian heart ventricles and is encoded by the gene Gja1 which has a single coding exon and therefore cannot be spliced. We previously identified that Gja1 mRNA undergoes endogenous internal translation initiated at one of several internal AUG (M) start codons, generating N-terminal truncated protein isoforms that retain the C-terminus distal to the start site. GJA1-20k, whose translation initiates at mRNA M213, is usually the most abundant isoform in cells and greatly increases after ischemic and metabolic stress. GJA1-20k consists of a small segment of the last transmembrane domain and the complete C-terminus tail of Cx43, with a total size of about 20 kDa. The original role identified for GJA1-20k is as an essential subunit that facilitates the trafficking of full-length Cx43 hexameric hemichannels to cell-cell contacts, generating traditional gap junctions between adjacent cells facilitating, in cardiac muscle, efficient spread of electrical excitation. GJA1-20k deficient mice (generated by a M213L substitution in Gja1) suffer poor electrical coupling between cardiomycytes and arrhythmogenic sudden death two to 4 weeks after their birth. We recently identified that exogenous GJA1-20k expression also mimics the effect of ischemic preconditioning in mouse heart. Furthermore, GJA1-20k localizes to the mitochondrial outer membrane and induces a protective and DRP1 independent form of mitochondrial fission, preserving ATP production and generating less reactive oxygen species (ROS) under metabolic stress, providing powerful protection of myocardium to ischemic insult. In this manuscript, we focus on the detailed roles of GJA1-20k in mitochondria, and its interaction with the actin cytoskeleton.
Collapse
|
13
|
Wei X, Chang ACH, Chang H, Xu S, Xue Y, Zhang Y, Lei M, Chang ACY, Zhang Q. Hypoglycemia-Exacerbated Mitochondrial Connexin 43 Accumulation Aggravates Cardiac Dysfunction in Diabetic Cardiomyopathy. Front Cardiovasc Med 2022; 9:800185. [PMID: 35369285 PMCID: PMC8967291 DOI: 10.3389/fcvm.2022.800185] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 02/10/2022] [Indexed: 11/29/2022] Open
Abstract
Background Diabetic cardiomyopathy (DCM) is a complex multifaceted disease responsible for elevated heart failure (HF) morbidity and mortality in patients with diabetes mellitus (DM). Patients with DCM exhibit subclinical diastolic dysfunction, progression toward systolic impairment, and abnormal electrophysiology. Hypoglycemia events that occur spontaneously or due to excess insulin administration threaten the lives of patients with DM—with the increased risk of sudden death. However, the molecular underpinnings of this fatal disease remain to be elucidated. Methods and Results Here, we used the established streptozotocin-induced DCM murine model to investigate how hypoglycemia aggravates DCM progression. We confirmed connexin 43 (Cx43) dissociation from cell–cell interaction and accumulation at mitochondrial inner membrane both in the cardiomyocytes of patients with DM and DCM murine. Here, we observed that cardiac diastolic function, induced by chronic hyperglycemia, was further aggravated upon hypoglycemia challenge. Similar contractile defects were recapitulated using neonatal mouse ventricular myocytes (NMVMs) under glucose fluctuation challenges. Using immunoprecipitation mass spectrometry, we identified and validated that hypoglycemia challenge activates the mitogen-activated protein kinase kinase (MAPK kinase) (MEK)/extracellular regulated protein kinase (ERK) and inhibits phosphoinositide 3-kinase (PI3K)/Akt pathways, which results in Cx43 phosphorylation by Src protein and translocation to mitochondria in cardiomyocytes. To determine causality, we overexpressed a mitochondrial targeting Cx43 (mtCx43) using adeno-associated virus serotype 2 (AAV2)/9. At normal blood glucose levels, mtCx43 overexpression recapitulated cardiac diastolic dysfunction as well as aberrant electrophysiology in vivo. Our findings give support for therapeutic targeting of MEK/ERK/Src and PI3K/Akt/Src pathways to prevent mtCx43-driven DCM. Conclusion DCM presents compensatory adaptation of mild mtCx43 accumulation, yet acute hypoglycemia challenges result in further accumulation of mtCx43 through the MEK/ERK/Src and PI3K/Akt/Src pathways. We provide evidence that Cx43 mislocalization is present in hearts of patients with DM hearts, STZ-induced DCM murine model, and glucose fluctuation challenged NMVMs. Mechanistically, we demonstrated that mtCx43 is responsible for inducing aberrant contraction and disrupts electrophysiology in cardiomyocytes and our results support targeting of mtCx43 in treating DCM.
Collapse
Affiliation(s)
- Xing Wei
- Department of Cardiology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Andrew Chia Hao Chang
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Haishuang Chang
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shan Xu
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yilin Xue
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yuanxin Zhang
- Department of Cardiology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ming Lei
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Alex Chia Yu Chang
- Department of Cardiology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Institute of Precision Medicine, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- *Correspondence: Alex Chia Yu Chang
| | - Qingyong Zhang
- Department of Cardiology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Qingyong Zhang
| |
Collapse
|
14
|
Gap Junction-Dependent and -Independent Functions of Connexin43 in Biology. BIOLOGY 2022; 11:biology11020283. [PMID: 35205149 PMCID: PMC8869330 DOI: 10.3390/biology11020283] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 02/08/2022] [Accepted: 02/10/2022] [Indexed: 12/21/2022]
Abstract
For the first time in animal evolution, the emergence of gap junctions allowed direct exchanges of cellular substances for communication between two cells. Innexin proteins constituted primordial gap junctions until the connexin protein emerged in deuterostomes and took over the gap junction function. After hundreds of millions of years of gene duplication, the connexin gene family now comprises 21 members in the human genome. Notably, GJA1, which encodes the Connexin43 protein, is one of the most widely expressed and commonly studied connexin genes. The loss of Gja1 in mice leads to swelling and a blockage of the right ventricular outflow tract and death of the embryos at birth, suggesting a vital role of Connexin43 gap junction in heart development. Since then, the importance of Connexin43-mediated gap junction function has been constantly expanded to other types of cells. Other than forming gap junctions, Connexin43 can also form hemichannels to release or uptake small molecules from the environment or even mediate many physiological processes in a gap junction-independent manner on plasma membranes. Surprisingly, Connexin43 also localizes to mitochondria in the cell, playing important roles in mitochondrial potassium import and respiration. At the molecular level, Connexin43 mRNA and protein are processed with very distinct mechanisms to yield carboxyl-terminal fragments with different sizes, which have their unique subcellular localization and distinct biological activities. Due to many exciting advancements in Connexin43 research, this review aims to start with a brief introduction of Connexin43 and then focuses on updating our knowledge of its gap junction-independent functions.
Collapse
|
15
|
Sankaramoorthy A, Roy S. High Glucose-Induced Apoptosis Is Linked to Mitochondrial Connexin 43 Level in RRECs: Implications for Diabetic Retinopathy. Cells 2021; 10:cells10113102. [PMID: 34831325 PMCID: PMC8618331 DOI: 10.3390/cells10113102] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 11/02/2021] [Accepted: 11/05/2021] [Indexed: 12/22/2022] Open
Abstract
Diabetic retinopathy (DR) is one of the most common causes of vision loss and blindness among the working-age population. High glucose (HG)-induced decrease in mitochondrial connexin 43 (mtCx43) level is known to promote mitochondrial fragmentation, cytochrome c release, and apoptosis in retinal endothelial cells associated with DR. In this study, we investigated whether counteracting HG-induced decrease in mtCx43 level would preserve mitochondrial integrity and prevent apoptosis. Rat retinal endothelial cells (RRECs) were grown in normal (N; 5 mM glucose) or HG (30 mM glucose) medium for 7 days. In parallel, cells grown in HG were transfected with Cx43 plasmid, or empty vector (EV), as control. Western blot (WB) analysis showed a significant decrease in mtCx43 level concomitant with increased cleaved caspase-3, Bax, cleaved PARP, and mitochondrial fragmentation in cells grown in HG condition compared to those grown in N medium. When cells grown in HG were transfected with Cx43 plasmid, mtCx43 level was significantly increased and resulted in reduced cleaved caspase-3, Bax, cleaved PARP and preservation of mitochondrial morphology with a significant decrease in the number of TUNEL-positive cells compared to those grown in HG alone. Findings from the study indicate a novel role for mtCx43 in regulating apoptosis and that maintenance of mtCx43 level could be useful in preventing HG-induced apoptosis by reducing mitochondrial fragmentation associated with retinal vascular cell loss in DR.
Collapse
Affiliation(s)
| | - Sayon Roy
- Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA;
- Department of Ophthalmology, Boston University School of Medicine, Boston, MA 02118, USA
- Correspondence: ; Tel.: +1-(617)-358-6801; Fax: +1-(617)-638-4177
| |
Collapse
|
16
|
Wang C, Qi C, Liu M, Wang L, Cheng G, Li L, Xing Y, Zhao X, Liu J. Protective effects of agrimonolide on hypoxia-induced H9c2 cell injury by maintaining mitochondrial homeostasis. J Cell Biochem 2021; 123:306-321. [PMID: 34724244 DOI: 10.1002/jcb.30169] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 10/12/2021] [Accepted: 10/18/2021] [Indexed: 12/19/2022]
Abstract
Cardiomyocyte death caused by hypoxia is one of the main causes of myocardial infarction or heart failure, and mitochondria play an important role in this process. Agrimonolide (AM) is a monomeric component extracted from Agrimonia pilosa L. and has antioxidant, antitumor, and anti-inflammatory effects. This study aimed to investigate the role and mechanism of AM in improving hypoxia-induced H9c2 cell damage. The results showed that low AM concentrations promote H9c2 cell proliferation and increase cellular ATP content. Transcriptome sequencing showed that AM induces differential expression of genes in H9c2 cells. Gene ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses revealed that these genes were concentrated in mitochondrial function. Subsequent experiments confirmed that AM regulates hypoxia-induced cell cycle arrest. AM inhibited the rate of apoptosis by regulating the expression of apoptosis-related proteins, reducing the level of cleaved Caspase 3 and Bax, and increasing the level of Bcl2, thereby protecting H9c2 cells from hypoxia-induced apoptosis. AM restored the mitochondrial membrane potential, inhibited the generation of ROS, maintained the normal shape of the mitochondria, improved the level of the mitochondrial functional proteins OPA1, MFN1, MFN2, Tom20, and increased the level of ATP. In conclusion, AM protects H9c2 cells from hypoxia-induced cell damage.
Collapse
Affiliation(s)
- Cheng Wang
- College of Veterinary Medicine, Shandong Agricultural University, Tai'an, Shandong, China
| | - Changxi Qi
- Research Center for Animal Disease Control Engineering, Shandong Agricultural University, Tai'an, Shandong, China
| | - Mingchao Liu
- College of Veterinary Medicine, Hebei Agricultural University, Baoding, Hebei, China
| | - Lumei Wang
- Research Center for Animal Disease Control Engineering, Shandong Agricultural University, Tai'an, Shandong, China
| | - Guodong Cheng
- College of Veterinary Medicine, Shandong Agricultural University, Tai'an, Shandong, China
| | - Liping Li
- Research Center for Animal Disease Control Engineering, Shandong Agricultural University, Tai'an, Shandong, China
| | - Yuxiao Xing
- College of Veterinary Medicine, Shandong Agricultural University, Tai'an, Shandong, China
| | - Xiaona Zhao
- College of Veterinary Medicine, Shandong Agricultural University, Tai'an, Shandong, China
| | - Jianzhu Liu
- Research Center for Animal Disease Control Engineering, Shandong Agricultural University, Tai'an, Shandong, China
| |
Collapse
|
17
|
Wang JD, Shao Y, Liu D, Liu NY, Zhu DY. Rictor/mTORC2 involves mitochondrial function in ES cells derived cardiomyocytes via mitochondrial Connexin 43. Acta Pharmacol Sin 2021; 42:1790-1797. [PMID: 33547375 PMCID: PMC8563760 DOI: 10.1038/s41401-020-00591-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 09/27/2020] [Indexed: 12/11/2022] Open
Abstract
Rictor is a key component of the mammalian target of rapamycin complex 2 (mTORC2) and is required for Akt phosphorylation (Ser473). Our previous study shows that knockdown of Rictor prevents cardiomyocyte differentiation from mouse embryonic stem (ES) cells and induces abnormal electrophysiology of ES cell-derived cardiomyocytes (ESC-CMs). Besides, knockdown of Rictor causes down-expression of connexin 43 (Cx43), the predominant gap junction protein, that is located in both the sarcolemma and mitochondria in cardiomyocytes. Mitochondrial Cx43 (mtCx43) plays a crucial role in mitochondrial function. In this study, we used the model of cardiomyocyte differentiation from mouse ES cells to elucidate the mechanisms for the mitochondrial damage in ESC-CMs after knockdown of Rictor. We showed swollen and ruptured mitochondria were observed after knockdown of Rictor under transmission electron microscope. ATP production and mitochondrial transmembrane potential were significantly decreased in Rictor-knockdown cells. Furthermore, knockdown of Rictor inhibited the activities of mitochondrial respiratory chain complex. The above-mentioned changes were linked to inhibiting the translocation of Cx43 into mitochondria by knockdown of Rictor. We revealed that knockdown of Rictor inactivated the mTOR/Akt signalling pathway and subsequently decreased HDAC6 expression, resulted in Hsp90 hyper-acetylation caused by HDAC6 inhibition, thus, inhibited the formation of Hsp90-Cx43-TOM20 complex. In conclusion, the mitochondrial Cx43 participates in shRNA-Rictor-induced mitochondrial function damage in the ESC-CMs.
Collapse
|
18
|
Pecoraro M, Marzocco S, Popolo A. Diazoxide Needs Mitochondrial Connexin43 to Exert Its Cytoprotective Effect in a Cellular Model of CoCl 2-Induced Hypoxia. Int J Mol Sci 2021; 22:ijms222111599. [PMID: 34769027 PMCID: PMC8583808 DOI: 10.3390/ijms222111599] [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: 09/27/2021] [Revised: 10/22/2021] [Accepted: 10/24/2021] [Indexed: 02/07/2023] Open
Abstract
Hypoxia is the leading cause of death in cardiomyocytes. Cells respond to oxygen deprivation by activating cytoprotective programs, such as mitochondrial connexin43 (mCx43) overexpression and the opening of mitochondrial KATP channels, aimed to reduce mitochondrial dysfunction. In this study we used an in vitro model of CoCl2-induced hypoxia to demonstrate that mCx43 and KATP channels cooperate to induce cytoprotection. CoCl2 administration induces apoptosis in H9c2 cells by increasing mitochondrial ROS production, intracellular and mitochondrial calcium overload and by inducing mitochondrial membrane depolarization. Diazoxide, an opener of KATP channels, reduces all these deleterious effects of CoCl2 only in the presence of mCx43. In fact, our results demonstrate that in the presence of radicicol, an inhibitor of Cx43 translocation to mitochondria, the cytoprotective effects of diazoxide disappear. In conclusion, these data confirm that there exists a close functional link between mCx43 and KATP channels.
Collapse
|
19
|
Zhao F, Zou MH. Role of the Mitochondrial Protein Import Machinery and Protein Processing in Heart Disease. Front Cardiovasc Med 2021; 8:749756. [PMID: 34651031 PMCID: PMC8505727 DOI: 10.3389/fcvm.2021.749756] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 08/26/2021] [Indexed: 12/12/2022] Open
Abstract
Mitochondria are essential organelles for cellular energy production, metabolic homeostasis, calcium homeostasis, cell proliferation, and apoptosis. About 99% of mammalian mitochondrial proteins are encoded by the nuclear genome, synthesized as precursors in the cytosol, and imported into mitochondria by mitochondrial protein import machinery. Mitochondrial protein import systems function not only as independent units for protein translocation, but also are deeply integrated into a functional network of mitochondrial bioenergetics, protein quality control, mitochondrial dynamics and morphology, and interaction with other organelles. Mitochondrial protein import deficiency is linked to various diseases, including cardiovascular disease. In this review, we describe an emerging class of protein or genetic variations of components of the mitochondrial import machinery involved in heart disease. The major protein import pathways, including the presequence pathway (TIM23 pathway), the carrier pathway (TIM22 pathway), and the mitochondrial intermembrane space import and assembly machinery, related translocases, proteinases, and chaperones, are discussed here. This review highlights the importance of mitochondrial import machinery in heart disease, which deserves considerable attention, and further studies are urgently needed. Ultimately, this knowledge may be critical for the development of therapeutic strategies in heart disease.
Collapse
Affiliation(s)
- Fujie Zhao
- Center for Molecular and Translational Medicine, Georgia State University, Atlanta, GA, United States
| | - Ming-Hui Zou
- Center for Molecular and Translational Medicine, Georgia State University, Atlanta, GA, United States
| |
Collapse
|
20
|
Estrogen alleviates hepatocyte necroptosis depending on GPER in hepatic ischemia reperfusion injury. J Physiol Biochem 2021; 78:125-137. [PMID: 34651286 DOI: 10.1007/s13105-021-00846-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 09/09/2021] [Indexed: 01/28/2023]
Abstract
Hepatic ischemia reperfusion injury (IRI) occurs in liver transplantation, complex liver resection, and hemorrhagic shock, which causes donor organ shortage and hepatic damage. The burst of reactive oxygen species (ROS) during reperfusion leads to cell apoptosis and necroptosis. It has been reported that estrogen could attenuate hepatic IRI. G protein estrogen receptor (GPER) mediates estrogen effects via nonclassic receptor systems. Here, we investigate whether estrogen protecting liver from hepatic IRI depends on GPER and the influence of GPER activation on hepatocyte necroptosis. We proved that estrogen had a protective effect on both hepatocyte hypoxia re-oxygen (H/R) challenge and mouse hepatic ischemia reperfusion model. However, the application of GPER specific antagonist G15 before estrogen inhibited this beneficial effect. The results of mitochondria functional measurement revealed that estrogen improved hepatocyte mitochondria function by activating GPER, which might benefit from the increased expression of connexin 43 (Cx43) in mitochondria. To investigate the relationship between GPER activation and necroptosis, we used caspase-3/7 inhibitor benzyloxycarbonyl-Asp(OMe)-Glu(OMe)-Val-Asp(OMe)-chloromethylketone (Z-DEVD-FMK) to eliminate the interference of apoptosis. Estrogen showed a protective effect on hepatic IRI after using Z-DEVD-FMK, which could be suppressed by G15. GPER activation decreased the level of receptor interacting protein kinase (RIPK) 3, phosphorylated (p-) RIPK1, and p-mixed lineage kinase domain-like (MLKL). The co-immunoprecipitation result indicated that GPER could bind with RIPK3. GPER is indispensable in estrogen protecting liver from IRI. GPER activation attenuates hepatocyte necroptosis by decreasing the level of RIPK3, p-RIPK1, and p-MLKL.
Collapse
|
21
|
Montes de Oca Balderas P. Mitochondria-plasma membrane interactions and communication. J Biol Chem 2021; 297:101164. [PMID: 34481840 PMCID: PMC8503596 DOI: 10.1016/j.jbc.2021.101164] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 08/24/2021] [Accepted: 09/01/2021] [Indexed: 11/28/2022] Open
Abstract
Mitochondria are known as the powerhouses of eukaryotic cells; however, they perform many other functions besides oxidative phosphorylation, including Ca2+ homeostasis, lipid metabolism, antiviral response, and apoptosis. Although other hypotheses exist, mitochondria are generally thought as descendants of an α-proteobacteria that adapted to the intracellular environment within an Asgard archaebacteria, which have been studied for decades as an organelle subdued by the eukaryotic cell. Nevertheless, several early electron microscopy observations hinted that some mitochondria establish specific interactions with certain plasma membrane (PM) domains in mammalian cells. Furthermore, recent findings have documented the direct physical and functional interaction of mitochondria and the PM, the organization of distinct complexes, and their communication through vesicular means. In yeast, some molecular players mediating this interaction have been elucidated, but only a few works have studied this interaction in mammalian cells. In addition, mitochondria can be translocated among cells through tunneling nanotubes or by other mechanisms, and free, intact, functional mitochondria have been reported in the blood plasma. Together, these findings challenge the conception of mitochondria as organelles subdued by the eukaryotic cell. This review discusses the evidence of the mitochondria interaction with the PM that has been long disregarded despite its importance in cell function, pathogenesis, and evolution. It also proposes a scheme of mitochondria–PM interactions with the intent to promote research and knowledge of this emerging pathway that promises to shift the current paradigms of cell biology.
Collapse
Affiliation(s)
- Pavel Montes de Oca Balderas
- Unidad de Neurobiología Dinámica, Department of Neurochemistry, Instituto Nacional de Neurología y Neurocirugía, Mexico City, Mexico; Lab. BL-305, Instituto de Fisiología Celular, Department of Cognitive Neuroscience, Universidad Nacional Autónoma de México, Mexico City, Mexico.
| |
Collapse
|
22
|
Choi M, Bonanno JA. Mitochondrial Targeting of the Ammonia-Sensitive Uncoupler SLC4A11 by the Chaperone-Mediated Carrier Pathway in Corneal Endothelium. Invest Ophthalmol Vis Sci 2021; 62:4. [PMID: 34499705 PMCID: PMC8434753 DOI: 10.1167/iovs.62.12.4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Purpose SLC4A11, an electrogenic H+ transporter, is found in the plasma membrane and mitochondria of corneal endothelium. However, the underlying mechanism of SLC4A11 targeting to mitochondria is unknown. Methods The presence of mitochondrial targeting sequences was examined using in silico mitochondrial proteomic analyses. Thiol crosslinked peptide binding to SLC4A11 was screened by untargeted liquid chromatography/tandem mass spectrometry (LC-MS/MS) analysis. Direct protein interactions between SLC4A11 and chaperones were examined using coimmunoprecipitation analysis and proximity ligation assay. Knockdown or pharmacologic inhibition of chaperones in human corneal endothelial cells (HCECs) or mouse corneal endothelial cells (MCECs), ex vivo kidney, or HA-SLC4A11–transfected fibroblasts was performed to investigate the functional consequences of interfering with mitochondrial SLC4A11 trafficking. Results SLC4A11 does not contain canonical N-terminal mitochondrial targeting sequences. LC-MS/MS analysis showed that HSC70 and/or HSP90 are bound to HA-SLC4A11–transfected PS120 fibroblast whole-cell lysates or isolated mitochondria, suggesting trafficking through the chaperone-mediated carrier pathway. SLC4A11 and either HSP90 or HSC70 complexes are directly bound to the mitochondrial surface receptor, TOM70. Interference with this trafficking leads to dysfunctional mitochondrial glutamine catabolism and increased reactive oxygen species production. In addition, glutamine (Gln) use upregulated SLC4A11, HSP70, and HSP90 expression in whole-cell lysates or purified mitochondria of HCECs and HA-SLC4A11–transfected fibroblasts. Conclusions HSP90 and HSC70 are critical in mediating mitochondrial SLC4A11 translocation in corneal endothelial cells and kidney. Gln promotes SLC4A11 import to the mitochondria, and the continuous oxidative stress derived from Gln catabolism induced HSP70 and HSP90, protecting cells against oxidative stress.
Collapse
Affiliation(s)
- Moonjung Choi
- Vision Science Program, Indiana University, School of Optometry, Bloomington, Indiana, United States
| | - Joseph A Bonanno
- Vision Science Program, Indiana University, School of Optometry, Bloomington, Indiana, United States
| |
Collapse
|
23
|
Quan Y, Du Y, Tong Y, Gu S, Jiang JX. Connexin Gap Junctions and Hemichannels in Modulating Lens Redox Homeostasis and Oxidative Stress in Cataractogenesis. Antioxidants (Basel) 2021; 10:1374. [PMID: 34573006 PMCID: PMC8464761 DOI: 10.3390/antiox10091374] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 08/24/2021] [Indexed: 11/18/2022] Open
Abstract
The lens is continuously exposed to oxidative stress insults, such as ultraviolet radiation and other oxidative factors, during the aging process. The lens possesses powerful oxidative stress defense systems to maintain its redox homeostasis, one of which employs connexin channels. Connexins are a family of proteins that form: (1) Hemichannels that mediate the communication between the intracellular and extracellular environments, and (2) gap junction channels that mediate cell-cell communication between adjacent cells. The avascular lens transports nutrition and metabolites through an extensive network of connexin channels, which allows the passage of small molecules, including antioxidants and oxidized wastes. Oxidative stress-induced post-translational modifications of connexins, in turn, regulates gap junction and hemichannel permeability. Recent evidence suggests that dysfunction of connexins gap junction channels and hemichannels may induce cataract formation through impaired redox homeostasis. Here, we review the recent advances in the knowledge of connexin channels in lens redox homeostasis and their response to cataract-related oxidative stress by discussing two major aspects: (1) The role of lens connexins and channels in oxidative stress and cataractogenesis, and (2) the impact and underlying mechanism of oxidative stress in regulating connexin channels.
Collapse
Affiliation(s)
| | | | | | | | - Jean X. Jiang
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX 78229, USA; (Y.Q.); (Y.D.); (Y.T.); (S.G.)
| |
Collapse
|
24
|
Martins-Marques T, Rodriguez-Sinovas A, Girao H. Cellular crosstalk in cardioprotection: Where and when do reactive oxygen species play a role? Free Radic Biol Med 2021; 169:397-409. [PMID: 33892116 DOI: 10.1016/j.freeradbiomed.2021.03.044] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 03/14/2021] [Accepted: 03/25/2021] [Indexed: 12/16/2022]
Abstract
A well-balanced intercellular communication between the different cells within the heart is vital for the maintenance of cardiac homeostasis and function. Despite remarkable advances on disease management and treatment, acute myocardial infarction remains the major cause of morbidity and mortality worldwide. Gold standard reperfusion strategies, namely primary percutaneous coronary intervention, are crucial to preserve heart function. However, reestablishment of blood flow and oxygen levels to the infarcted area are also associated with an accumulation of reactive oxygen species (ROS), leading to oxidative damage and cardiomyocyte death, a phenomenon termed myocardial reperfusion injury. In addition, ROS signaling has been demonstrated to regulate multiple biological pathways, including cell differentiation and intercellular communication. Given the importance of cell-cell crosstalk in the coordinated response after cell injury, in this review, we will discuss the impact of ROS in the different forms of inter- and intracellular communication, as well as the role of gap junctions, tunneling nanotubes and extracellular vesicles in the propagation of oxidative damage in cardiac diseases, particularly in the context of ischemia/reperfusion injury.
Collapse
Affiliation(s)
- Tania Martins-Marques
- Univ Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, Portugal; Univ Coimbra, Center for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal; Clinical Academic Centre of Coimbra (CACC), Coimbra, Portugal
| | - Antonio Rodriguez-Sinovas
- Cardiovascular Diseases Research Group, Department of Cardiology, Vall D'Hebron Institut de Recerca (VHIR), Vall D'Hebron Hospital Universitari, Vall D'Hebron Barcelona Hospital Campus, Passeig Vall D'Hebron, 119-129, 08035, Barcelona, Spain; Departament de Medicina, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain; Centro de Investigación Biomédica en Red Sobre Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
| | - Henrique Girao
- Univ Coimbra, Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, Coimbra, Portugal; Univ Coimbra, Center for Innovative Biomedicine and Biotechnology (CIBB), Coimbra, Portugal; Clinical Academic Centre of Coimbra (CACC), Coimbra, Portugal.
| |
Collapse
|
25
|
Bou-Teen D, Kaludercic N, Weissman D, Turan B, Maack C, Di Lisa F, Ruiz-Meana M. Mitochondrial ROS and mitochondria-targeted antioxidants in the aged heart. Free Radic Biol Med 2021; 167:109-124. [PMID: 33716106 DOI: 10.1016/j.freeradbiomed.2021.02.043] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 02/14/2021] [Accepted: 02/26/2021] [Indexed: 12/12/2022]
Abstract
Excessive mitochondrial ROS production has been causally linked to the pathophysiology of aging in the heart and other organs, and plays a deleterious role in several age-related cardiac pathologies, including myocardial ischemia-reperfusion injury and heart failure, the two worldwide leading causes of death and disability in the elderly. However, ROS generation is also a fundamental mitochondrial function that orchestrates several signaling pathways, some of them exerting cardioprotective effects. In cardiac myocytes, mitochondria are particularly abundant and are specialized in subcellular populations, in part determined by their relationships with other organelles and their cyclic calcium handling activity necessary for adequate myocardial contraction/relaxation and redox balance. Depending on their subcellular location, mitochondria can themselves be differentially targeted by ROS and display distinct age-dependent functional decline. Thus, precise mitochondria-targeted therapies aimed at counteracting unregulated ROS production are expected to have therapeutic benefits in certain aging-related heart conditions. However, for an adequate design of such therapies, it is necessary to unravel the complex and dynamic interactions between mitochondria and other cellular processes.
Collapse
Affiliation(s)
- Diana Bou-Teen
- Hospital Universitari Vall d'Hebron, Department of Cardiology, Vall d'Hebron Institut de Recerca (VHIR),Universitat Autonoma de Barcelona, 08035, Barcelona, Spain
| | - Nina Kaludercic
- Neuroscience Institute, National Research Council of Italy (CNR), via Ugo Bassi 58/B, 35131, Padova, Italy; Fondazione Istituto di Ricerca Pediatrica Città della Speranza (IRP), 35129, Padova, Italy
| | - David Weissman
- Comprehensive Heart Failure Center, University Clinic Würzburg, 97080, Würzburg, Germany
| | - Belma Turan
- Departments of Biophysics, Faculty of Medicine, Lokman Hekim University, Ankara, Turkey
| | - Christoph Maack
- Comprehensive Heart Failure Center, University Clinic Würzburg, 97080, Würzburg, Germany
| | - Fabio Di Lisa
- Neuroscience Institute, National Research Council of Italy (CNR), via Ugo Bassi 58/B, 35131, Padova, Italy; Department of Biomedical Sciences, University of Padova, via Ugo Bassi 58/B, 35131, Padova, Italy
| | - Marisol Ruiz-Meana
- Hospital Universitari Vall d'Hebron, Department of Cardiology, Vall d'Hebron Institut de Recerca (VHIR),Universitat Autonoma de Barcelona, 08035, Barcelona, Spain; Centro de Investigación Biomédica en Red-CV, CIBER-CV, Spain.
| |
Collapse
|
26
|
Connexins in the Heart: Regulation, Function and Involvement in Cardiac Disease. Int J Mol Sci 2021; 22:ijms22094413. [PMID: 33922534 PMCID: PMC8122935 DOI: 10.3390/ijms22094413] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/12/2021] [Accepted: 04/20/2021] [Indexed: 12/20/2022] Open
Abstract
Connexins are a family of transmembrane proteins that play a key role in cardiac physiology. Gap junctional channels put into contact the cytoplasms of connected cardiomyocytes, allowing the existence of electrical coupling. However, in addition to this fundamental role, connexins are also involved in cardiomyocyte death and survival. Thus, chemical coupling through gap junctions plays a key role in the spreading of injury between connected cells. Moreover, in addition to their involvement in cell-to-cell communication, mounting evidence indicates that connexins have additional gap junction-independent functions. Opening of unopposed hemichannels, located at the lateral surface of cardiomyocytes, may compromise cell homeostasis and may be involved in ischemia/reperfusion injury. In addition, connexins located at non-canonical cell structures, including mitochondria and the nucleus, have been demonstrated to be involved in cardioprotection and in regulation of cell growth and differentiation. In this review, we will provide, first, an overview on connexin biology, including their synthesis and degradation, their regulation and their interactions. Then, we will conduct an in-depth examination of the role of connexins in cardiac pathophysiology, including new findings regarding their involvement in myocardial ischemia/reperfusion injury, cardiac fibrosis, gene transcription or signaling regulation.
Collapse
|
27
|
Hirschhäuser C, Lissoni A, Görge PM, Lampe PD, Heger J, Schlüter KD, Leybaert L, Schulz R, Boengler K. Connexin 43 phosphorylation by casein kinase 1 is essential for the cardioprotection by ischemic preconditioning. Basic Res Cardiol 2021; 116:21. [PMID: 33751227 PMCID: PMC7985055 DOI: 10.1007/s00395-021-00861-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 03/10/2021] [Indexed: 02/07/2023]
Abstract
Myocardial connexin 43 (Cx43) forms gap junctions and hemichannels, and is also present within subsarcolemmal mitochondria. The protein is phosphorylated by several kinases including mitogen-activated protein kinase (MAPK), protein kinase C (PKC), and casein kinase 1 (CK1). A reduction in Cx43 content abrogates myocardial infarct size reduction by ischemic preconditioning (IPC). The present study characterizes the contribution of Cx43 phosphorylation towards mitochondrial function, hemichannel activity, and the cardioprotection by IPC in wild-type (WT) mice and in mice in which Cx43-phosphorylation sites targeted by above kinases are mutated to non-phosphorylatable residues (Cx43MAPKmut, Cx43PKCmut, and Cx43CK1mut mice). The amount of Cx43 in the left ventricle and in mitochondria was reduced in all mutant strains compared to WT mice and Cx43 phosphorylation was altered at residues not directly targeted by the mutations. Whereas complex 1 respiration was reduced in all strains, complex 2 respiration was decreased in Cx43CK1mut mice only. In Cx43 epitope-mutated mice, formation of reactive oxygen species and opening of the mitochondrial permeability transition pore were not affected. The hemichannel open probability was reduced in Cx43PKCmut and Cx43CK1mut but not in Cx43MAPKmut cardiomyocytes. Infarct size in isolated saline-perfused hearts after ischemia/reperfusion (45 min/120 min) was comparable between genotypes and was significantly reduced by IPC (3 × 3 min ischemia/5 min reperfusion) in WT, Cx43MAPKmut, and Cx43PKCmut, but not in Cx43CK1mut mice, an effect independent from the amount of Cx43 and the probability of hemichannel opening. Taken together, our study shows that alterations of Cx43 phosphorylation affect specific cellular functions and highlights the importance of Cx43 phosphorylation by CK1 for IPC's cardioprotection.
Collapse
Affiliation(s)
- Christine Hirschhäuser
- Institut für Physiologie, Justus-Liebig Universität Gießen, Aulweg 129, 35392, Giessen, Germany
| | - Alessio Lissoni
- Department of Basic Medical Sciences, Physiology group, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | | | - Paul D Lampe
- Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Jacqueline Heger
- Institut für Physiologie, Justus-Liebig Universität Gießen, Aulweg 129, 35392, Giessen, Germany
| | - Klaus-Dieter Schlüter
- Institut für Physiologie, Justus-Liebig Universität Gießen, Aulweg 129, 35392, Giessen, Germany
| | - Luc Leybaert
- Department of Basic Medical Sciences, Physiology group, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Rainer Schulz
- Institut für Physiologie, Justus-Liebig Universität Gießen, Aulweg 129, 35392, Giessen, Germany
| | - Kerstin Boengler
- Institut für Physiologie, Justus-Liebig Universität Gießen, Aulweg 129, 35392, Giessen, Germany.
| |
Collapse
|
28
|
Natha CM, Vemulapalli V, Fiori MC, Chang CWT, Altenberg GA. Connexin hemichannel inhibitors with a focus on aminoglycosides. Biochim Biophys Acta Mol Basis Dis 2021; 1867:166115. [PMID: 33711451 DOI: 10.1016/j.bbadis.2021.166115] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 02/06/2021] [Accepted: 02/22/2021] [Indexed: 12/31/2022]
Abstract
Connexins are membrane proteins involved directly in cell-to-cell communication through the formation of gap-junctional channels. These channels result from the head-to-head docking of two hemichannels, one from each of two adjacent cells. Undocked hemichannels are also present at the plasma membrane where they mediate the efflux of molecules that participate in autocrine and paracrine signaling, but abnormal increase in hemichannel activity can lead to cell damage in disorders such as cardiac infarct, stroke, deafness, cataracts, and skin diseases. For this reason, connexin hemichannels have emerged as a valid therapeutic target. Know small molecule hemichannel inhibitors are not ideal leads for the development of better drugs for clinical use because they are not specific and/or have toxic effects. Newer inhibitors are more selective and include connexin mimetic peptides, anti-connexin antibodies and drugs that reduce connexin expression such as antisense oligonucleotides. Re-purposed drugs and their derivatives are also promising because of the significant experience with their clinical use. Among these, aminoglycoside antibiotics have been identified as inhibitors of connexin hemichannels that do not inhibit gap-junctional channels. In this review, we discuss connexin hemichannels and their inhibitors, with a focus on aminoglycoside antibiotics and derivatives of kanamycin A that inhibit connexin hemichannels, but do not have antibiotic effect.
Collapse
Affiliation(s)
- Cristina M Natha
- Department of Cell Physiology and Molecular Biophysics, and Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Varun Vemulapalli
- Department of Cell Physiology and Molecular Biophysics, and Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Mariana C Fiori
- Department of Cell Physiology and Molecular Biophysics, and Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Cheng-Wei T Chang
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT, USA
| | - Guillermo A Altenberg
- Department of Cell Physiology and Molecular Biophysics, and Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
| |
Collapse
|
29
|
Koma R, Shibaguchi T, Pérez López C, Oka T, Jue T, Takakura H, Masuda K. Localization of myoglobin in mitochondria: implication in regulation of mitochondrial respiration in rat skeletal muscle. Physiol Rep 2021; 9:e14769. [PMID: 33650803 PMCID: PMC7923563 DOI: 10.14814/phy2.14769] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 02/01/2021] [Indexed: 11/24/2022] Open
Abstract
Mitochondria play a principal role in metabolism, and mitochondrial respiration is an important process for producing adenosine triphosphate. Recently, we showed the possibility that the muscle-specific protein myoglobin (Mb) interacts with mitochondrial complex IV to augment the respiration capacity in skeletal muscles. However, the precise mechanism for the Mb-mediated upregulation remains under debate. The aim of this study was to ascertain whether Mb is truly integrated into the mitochondria of skeletal muscle and to investigate the submitochondrial localization. Isolated mitochondria from rat gastrocnemius muscle were subjected to different proteinase K (PK) concentrations to digest proteins interacting with the outer membrane. Western blotting analysis revealed that the PK digested translocase of outer mitochondrial membrane 20 (Tom20), and the immunoreactivity of Tom20 decreased with the amount of PK used. However, the immunoreactivity of Mb with PK treatment was better preserved, indicating that Mb is integrated into the mitochondria of skeletal muscle. The mitochondrial protease protection assay experiments suggested that Mb localizes within the mitochondria in the inner membrane from the intermembrane space side. These results strongly suggest that Mb inside muscle mitochondria could be implicated in the regulation of mitochondrial respiration via complex IV.
Collapse
Affiliation(s)
- Rikuhide Koma
- Graduate School of Human and Socio‐Environmental StudiesKanazawa UniversityIshikawaJapan
| | | | | | - Toshihiko Oka
- Department of Life ScienceRikkyo UniversityTokyoJapan
| | - Thomas Jue
- Department of Biochemistry and Molecular MedicineUniversity of California DavisDavisCAUSA
| | - Hisashi Takakura
- Faculty of Health and Sports ScienceDoshisha UniversityKyotoJapan
| | - Kazumi Masuda
- Graduate School of Human and Socio‐Environmental StudiesKanazawa UniversityIshikawaJapan
- Faculty of Human SciencesKanazawa UniversityIshikawaJapan
| |
Collapse
|
30
|
Hua R, Zhang J, Riquelme MA, Jiang JX. Connexin Gap Junctions and Hemichannels Link Oxidative Stress to Skeletal Physiology and Pathology. Curr Osteoporos Rep 2021; 19:66-74. [PMID: 33403446 PMCID: PMC8174533 DOI: 10.1007/s11914-020-00645-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/16/2020] [Indexed: 12/15/2022]
Abstract
PURPOSE OF REVIEW The goal of this review is to provide an overview of the impact and underlying mechanism of oxidative stress on connexin channel function, and their roles in skeletal aging, estrogen deficiency, and glucocorticoid excess associated bone loss. RECENT FINDINGS Connexin hemichannel opening is increased under oxidative stress conditions, which confers a cell protective role against oxidative stress-induced cell death. Oxidative stress acts as a key contributor to aging, estrogen deficiency, and glucocorticoid excess-induced osteoporosis and impairs osteocytic network and connexin gap junction communication. This paper reviews the current knowledge for the role of oxidative stress and connexin channels in the pathogenesis of osteoporosis and physiological and pathological responses of connexin channels to oxidative stress. Oxidative stress decreases osteocyte viability and impairs the balance of anabolic and catabolic responses. Connexin 43 (Cx43) channels play a critical role in bone remodeling, mechanotransduction, and survival of osteocytes. Under oxidative stress conditions, there is a consistent reduction of Cx43 expression, while the opening of Cx43 hemichannels protects osteocytes against cell injury caused by oxidative stress.
Collapse
Affiliation(s)
- Rui Hua
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX, USA
| | - Jingruo Zhang
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX, USA
| | - Manuel A Riquelme
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX, USA
| | - Jean X Jiang
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center, San Antonio, TX, USA.
| |
Collapse
|
31
|
Anthracycline-induced cardiomyopathy: cellular and molecular mechanisms. Clin Sci (Lond) 2021; 134:1859-1885. [PMID: 32677679 DOI: 10.1042/cs20190653] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 07/02/2020] [Accepted: 07/03/2020] [Indexed: 02/06/2023]
Abstract
Despite the known risk of cardiotoxicity, anthracyclines are widely prescribed chemotherapeutic agents. They are broadly characterized as being a robust effector of cellular apoptosis in rapidly proliferating cells through its actions in the nucleus and formation of reactive oxygen species (ROS). And, despite the early use of dexrazoxane, no effective treatment strategy has emerged to prevent the development of cardiomyopathy, despite decades of study, suggesting that much more insight into the underlying mechanism of the development of cardiomyopathy is needed. In this review, we detail the specific intracellular activities of anthracyclines, from the cell membrane to the sarcoplasmic reticulum, and highlight potential therapeutic windows that represent the forefront of research into the underlying causes of anthracycline-induced cardiomyopathy.
Collapse
|
32
|
Boengler K, Rohrbach S, Weissmann N, Schulz R. Importance of Cx43 for Right Ventricular Function. Int J Mol Sci 2021; 22:ijms22030987. [PMID: 33498172 PMCID: PMC7863922 DOI: 10.3390/ijms22030987] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/13/2021] [Accepted: 01/18/2021] [Indexed: 11/16/2022] Open
Abstract
In the heart, connexins form gap junctions, hemichannels, and are also present within mitochondria, with connexin 43 (Cx43) being the most prominent connexin in the ventricles. Whereas the role of Cx43 is well established for the healthy and diseased left ventricle, less is known about the importance of Cx43 for the development of right ventricular (RV) dysfunction. The present article focusses on the importance of Cx43 for the developing heart. Furthermore, we discuss the expression and localization of Cx43 in the diseased RV, i.e., in the tetralogy of Fallot and in pulmonary hypertension, in which the RV is affected, and RV hypertrophy and failure occur. We will also introduce other Cx molecules that are expressed in RV and surrounding tissues and have been reported to be involved in RV pathophysiology. Finally, we highlight therapeutic strategies aiming to improve RV function in pulmonary hypertension that are associated with alterations of Cx43 expression and function.
Collapse
|
33
|
Andelova K, Egan Benova T, Szeiffova Bacova B, Sykora M, Prado NJ, Diez ER, Hlivak P, Tribulova N. Cardiac Connexin-43 Hemichannels and Pannexin1 Channels: Provocative Antiarrhythmic Targets. Int J Mol Sci 2020; 22:ijms22010260. [PMID: 33383853 PMCID: PMC7795512 DOI: 10.3390/ijms22010260] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/23/2020] [Accepted: 12/24/2020] [Indexed: 12/12/2022] Open
Abstract
Cardiac connexin-43 (Cx43) creates gap junction channels (GJCs) at intercellular contacts and hemi-channels (HCs) at the peri-junctional plasma membrane and sarcolemmal caveolae/rafts compartments. GJCs are fundamental for the direct cardiac cell-to-cell transmission of electrical and molecular signals which ensures synchronous myocardial contraction. The HCs and structurally similar pannexin1 (Panx1) channels are active in stressful conditions. These channels are essential for paracrine and autocrine communication through the release of ions and signaling molecules to the extracellular environment, or for uptake from it. The HCs and Panx1 channel-opening profoundly affects intracellular ionic homeostasis and redox status and facilitates via purinergic signaling pro-inflammatory and pro-fibrotic processes. These conditions promote cardiac arrhythmogenesis due to the impairment of the GJCs and selective ion channel function. Crosstalk between GJCs and HCs/Panx1 channels could be crucial in the development of arrhythmogenic substrates, including fibrosis. Despite the knowledge gap in the regulation of these channels, current evidence indicates that HCs and Panx1 channel activation can enhance the risk of cardiac arrhythmias. It is extremely challenging to target HCs and Panx1 channels by inhibitory agents to hamper development of cardiac rhythm disorders. Progress in this field may contribute to novel therapeutic approaches for patients prone to develop atrial or ventricular fibrillation.
Collapse
Affiliation(s)
- Katarina Andelova
- Centre of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, 84104 Bratislava, Slovakia; (K.A.); (T.E.B.); (B.S.B.); (M.S.)
| | - Tamara Egan Benova
- Centre of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, 84104 Bratislava, Slovakia; (K.A.); (T.E.B.); (B.S.B.); (M.S.)
| | - Barbara Szeiffova Bacova
- Centre of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, 84104 Bratislava, Slovakia; (K.A.); (T.E.B.); (B.S.B.); (M.S.)
| | - Matus Sykora
- Centre of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, 84104 Bratislava, Slovakia; (K.A.); (T.E.B.); (B.S.B.); (M.S.)
| | - Natalia Jorgelina Prado
- Instituto de Medicina y Biología Experimental de Cuyo, Consejo Nacional de Investigaciones Científicas y Técnicas, M5500 Mendoza, Argentina; (N.J.P.); (E.R.D.)
| | - Emiliano Raul Diez
- Instituto de Medicina y Biología Experimental de Cuyo, Consejo Nacional de Investigaciones Científicas y Técnicas, M5500 Mendoza, Argentina; (N.J.P.); (E.R.D.)
| | - Peter Hlivak
- Department of Arrhythmias and Pacing, National Institute of Cardiovascular Diseases, Pod Krásnou Hôrkou 1, 83348 Bratislava, Slovakia;
| | - Narcis Tribulova
- Centre of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, 84104 Bratislava, Slovakia; (K.A.); (T.E.B.); (B.S.B.); (M.S.)
- Correspondence: ; Tel.: +421-2-32295-423
| |
Collapse
|
34
|
Mulkearns-Hubert EE, Reizes O, Lathia JD. Connexins in Cancer: Jekyll or Hyde? Biomolecules 2020; 10:E1654. [PMID: 33321749 PMCID: PMC7764653 DOI: 10.3390/biom10121654] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 12/07/2020] [Accepted: 12/08/2020] [Indexed: 12/16/2022] Open
Abstract
The expression, localization, and function of connexins, the protein subunits that comprise gap junctions, are often altered in cancer. In addition to cell-cell coupling through gap junction channels, connexins also form hemichannels that allow communication between the cell and the extracellular space and perform non-junctional intracellular activities. Historically, connexins have been considered tumor suppressors; however, they can also serve tumor-promoting functions in some contexts. Here, we review the literature surrounding connexins in cancer cells in terms of specific connexin functions and propose that connexins function upstream of most, if not all, of the hallmarks of cancer. The development of advanced connexin targeting approaches remains an opportunity for the field to further interrogate the role of connexins in cancer phenotypes, particularly through the use of in vivo models. More specific modulators of connexin function will both help elucidate the functions of connexins in cancer and advance connexin-specific therapies in the clinic.
Collapse
Affiliation(s)
- Erin E. Mulkearns-Hubert
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA; (O.R.); (J.D.L.)
| | - Ofer Reizes
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA; (O.R.); (J.D.L.)
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106, USA
- Department of Molecular Medicine, Cleveland Clinic Lerner College, Medicine of Case Western Reserve University, Cleveland, OH 44195, USA
| | - Justin D. Lathia
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA; (O.R.); (J.D.L.)
- Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106, USA
- Department of Molecular Medicine, Cleveland Clinic Lerner College, Medicine of Case Western Reserve University, Cleveland, OH 44195, USA
- Rose Ella Burkhardt Brain Tumor and Neuro-Oncology Center, Cleveland Clinic, Cleveland, OH, 44195, USA
| |
Collapse
|
35
|
Rusiecka OM, Montgomery J, Morel S, Batista-Almeida D, Van Campenhout R, Vinken M, Girao H, Kwak BR. Canonical and Non-Canonical Roles of Connexin43 in Cardioprotection. Biomolecules 2020; 10:biom10091225. [PMID: 32842488 PMCID: PMC7563275 DOI: 10.3390/biom10091225] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 08/17/2020] [Accepted: 08/20/2020] [Indexed: 12/15/2022] Open
Abstract
Since the mid-20th century, ischemic heart disease has been the world’s leading cause of death. Developing effective clinical cardioprotection strategies would make a significant impact in improving both quality of life and longevity in the worldwide population. Both ex vivo and in vivo animal models of cardiac ischemia/reperfusion (I/R) injury are robustly used in research. Connexin43 (Cx43), the predominant gap junction channel-forming protein in cardiomyocytes, has emerged as a cardioprotective target. Cx43 posttranslational modifications as well as cellular distribution are altered during cardiac reperfusion injury, inducing phosphorylation states and localization detrimental to maintaining intercellular communication and cardiac conduction. Pre- (before ischemia) and post- (after ischemia but before reperfusion) conditioning can abrogate this injury process, preserving Cx43 and reducing cell death. Pre-/post-conditioning has been shown to largely rely on the presence of Cx43, including mitochondrial Cx43, which is implicated to play a major role in pre-conditioning. Posttranslational modifications of Cx43 after injury alter the protein interactome, inducing negative protein cascades and altering protein trafficking, which then causes further damage post-I/R injury. Recently, several peptides based on the Cx43 sequence have been found to successfully diminish cardiac injury in pre-clinical studies.
Collapse
Affiliation(s)
- Olga M. Rusiecka
- Department of Pathology and Immunology, University of Geneva, CH-1211 Geneva, Switzerland; (O.M.R.); (J.M.); (S.M.)
| | - Jade Montgomery
- Department of Pathology and Immunology, University of Geneva, CH-1211 Geneva, Switzerland; (O.M.R.); (J.M.); (S.M.)
| | - Sandrine Morel
- Department of Pathology and Immunology, University of Geneva, CH-1211 Geneva, Switzerland; (O.M.R.); (J.M.); (S.M.)
| | - Daniela Batista-Almeida
- Univ Coimbra, Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, 3000-548 Coimbra, Portugal; (D.B.-A.); (H.G.)
- Univ Coimbra, Center for Innovative Biomedicine and Biotechnology (CIBB), 3000-548 Coimbra, Portugal
- Clinical Academic Centre of Coimbra (CACC), 3000-548 Coimbra, Portugal
| | - Raf Van Campenhout
- Department of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel, 1090 Brussels, Belgium; (R.V.C.); (M.V.)
| | - Mathieu Vinken
- Department of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel, 1090 Brussels, Belgium; (R.V.C.); (M.V.)
| | - Henrique Girao
- Univ Coimbra, Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, 3000-548 Coimbra, Portugal; (D.B.-A.); (H.G.)
- Univ Coimbra, Center for Innovative Biomedicine and Biotechnology (CIBB), 3000-548 Coimbra, Portugal
- Clinical Academic Centre of Coimbra (CACC), 3000-548 Coimbra, Portugal
| | - Brenda R. Kwak
- Department of Pathology and Immunology, University of Geneva, CH-1211 Geneva, Switzerland; (O.M.R.); (J.M.); (S.M.)
- Correspondence:
| |
Collapse
|
36
|
Hausenloy DJ, Schulz R, Girao H, Kwak BR, De Stefani D, Rizzuto R, Bernardi P, Di Lisa F. Mitochondrial ion channels as targets for cardioprotection. J Cell Mol Med 2020; 24:7102-7114. [PMID: 32490600 PMCID: PMC7339171 DOI: 10.1111/jcmm.15341] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 03/31/2020] [Accepted: 04/12/2020] [Indexed: 12/14/2022] Open
Abstract
Acute myocardial infarction (AMI) and the heart failure (HF) that often result remain the leading causes of death and disability worldwide. As such, new therapeutic targets need to be discovered to protect the myocardium against acute ischaemia/reperfusion (I/R) injury in order to reduce myocardial infarct (MI) size, preserve left ventricular function and prevent the onset of HF. Mitochondrial dysfunction during acute I/R injury is a critical determinant of cell death following AMI, and therefore, ion channels in the inner mitochondrial membrane, which are known to influence cell death and survival, provide potential therapeutic targets for cardioprotection. In this article, we review the role of mitochondrial ion channels, which are known to modulate susceptibility to acute myocardial I/R injury, and we explore their potential roles as therapeutic targets for reducing MI size and preventing HF following AMI.
Collapse
Affiliation(s)
- Derek J. Hausenloy
- Cardiovascular & Metabolic Disorders ProgramDuke‐National University of Singapore Medical SchoolSingaporeSingapore
- National Heart Research Institute SingaporeNational Heart CentreSingaporeSingapore
- Yong Loo Lin School of MedicineNational University SingaporeSingaporeSingapore
- The Hatter Cardiovascular InstituteUniversity College LondonLondonUK
- Cardiovascular Research CenterCollege of Medical and Health SciencesAsia UniversityTaichung CityTaiwan
| | - Rainer Schulz
- Institute of PhysiologyJustus‐Liebig University GiessenGiessenGermany
| | - Henrique Girao
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of MedicineUniversity of CoimbraCoimbraPortugal
- Center for Innovative Biomedicine and Biotechnology (CIBB)University of CoimbraCoimbraPortugal
- Clinical Academic Centre of CoimbraCACCCoimbraPortugal
| | - Brenda R. Kwak
- Department of Pathology and ImmunologyUniversity of GenevaGenevaSwitzerland
| | - Diego De Stefani
- Department of Biomedical SciencesUniversity of PadovaPadovaItaly
| | - Rosario Rizzuto
- Department of Biomedical SciencesUniversity of PadovaPadovaItaly
| | - Paolo Bernardi
- Department of Biomedical SciencesUniversity of PadovaPadovaItaly
- CNR Neuroscience InstitutePadovaItaly
| | - Fabio Di Lisa
- Department of Biomedical SciencesUniversity of PadovaPadovaItaly
- CNR Neuroscience InstitutePadovaItaly
| |
Collapse
|
37
|
Li J, Sun D, Li Y. Novel Findings and Therapeutic Targets on Cardioprotection of Ischemia/ Reperfusion Injury in STEMI. Curr Pharm Des 2020; 25:3726-3739. [PMID: 31692431 DOI: 10.2174/1381612825666191105103417] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 10/30/2019] [Indexed: 12/19/2022]
Abstract
Acute ST-segment elevation myocardial infarction (STEMI) remains a leading cause of morbidity and mortality around the world. A large number of STEMI patients after the infarction gradually develop heart failure due to the infarcted myocardium. Timely reperfusion is essential to salvage ischemic myocardium from the infarction, but the restoration of coronary blood flow in the infarct-related artery itself induces myocardial injury and cardiomyocyte death, known as ischemia/reperfusion injury (IRI). The factors contributing to IRI in STEMI are complex, and microvascular obstruction, inflammation, release of reactive oxygen species, myocardial stunning, and activation of myocardial cell death are involved. Therefore, additional cardioprotection is required to prevent the heart from IRI. Although many mechanical conditioning procedures and pharmacological agents have been identified as effective cardioprotective approaches in animal studies, their translation into the clinical practice has been relatively disappointing due to a variety of reasons. With new emerging data on cardioprotection in STEMI over the past few years, it is mandatory to reevaluate the effectiveness of "old" cardioprotective interventions and highlight the novel therapeutic targets and new treatment strategies of cardioprotection.
Collapse
Affiliation(s)
- Jianqiang Li
- Department of Cardiology, The First Affiliated Hospital of Harbin Medical University, Harbin Medical University, Harbin, China
| | - Danghui Sun
- Department of Cardiology, The First Affiliated Hospital of Harbin Medical University, Harbin Medical University, Harbin, China
| | - Yue Li
- Department of Cardiology, The First Affiliated Hospital of Harbin Medical University, Harbin Medical University, Harbin, China
| |
Collapse
|
38
|
Wang M, Smith K, Yu Q, Miller C, Singh K, Sen CK. Mitochondrial connexin 43 in sex-dependent myocardial responses and estrogen-mediated cardiac protection following acute ischemia/reperfusion injury. Basic Res Cardiol 2019; 115:1. [PMID: 31741053 DOI: 10.1007/s00395-019-0759-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 11/05/2019] [Indexed: 01/23/2023]
Abstract
Preserving mitochondrial activity is crucial in rescuing cardiac function following acute myocardial ischemia/reperfusion (I/R). The sex difference in myocardial functional recovery has been observed after I/R. Given the key role of mitochondrial connexin43 (Cx43) in cardiac protection initiated by ischemic preconditioning, we aimed to determine the implication of mitochondrial Cx43 in sex-related myocardial responses and to examine the effect of estrogen (17β-estradiol, E2) on Cx43, particularly mitochondrial Cx43-involved cardiac protection following I/R. Mouse primary cardiomyocytes and isolated mouse hearts (from males, females, ovariectomized females, and doxycycline-inducible Tnnt2-controlled Cx43 knockout without or with acute post-ischemic E2 treatment) were subjected to simulated I/R in culture or Langendorff I/R (25-min warm ischemia/40-min reperfusion), respectively. Mitochondrial membrane potential and mitochondrial superoxide production were measured in cardiomyocytes. Myocardial function and infarct size were determined. Cx43 and its isoform, Gja1-20k, were assessed in mitochondria. Immunoelectron microscopy and co-immunoprecipitation were also used to examine mitochondrial Cx43 and its interaction with estrogen receptor-α by E2 in mitochondria, respectively. There were sex disparities in stress-induced cardiomyocyte mitochondrial function. E2 partially restored mitochondrial activity in cardiomyocytes following acute injury. Post-ischemia infusion of E2 improved functional recovery and reduced infarct size with increased Cx43 content and phosphorylation in mitochondria. Ablation of cardiac Cx43 aggravated mitochondrial damage and abolished E2-mediated cardiac protection during I/R. Female mice were more resistant to myocardial I/R than age-matched males with greater protective role of mitochondrial Cx43 in female hearts. Post-ischemic E2 usage augmented mitochondrial Cx43 content and phosphorylation, increased mitochondrial Gja1-20k, and showed cardiac protection.
Collapse
Affiliation(s)
- Meijing Wang
- Department of Surgery, Indiana University School of Medicine, 950 W. Walnut Street, R2 E319, Indianapolis, IN, 46202, USA.
| | - Kwynlyn Smith
- Department of Surgery, Indiana University School of Medicine, 950 W. Walnut Street, R2 E319, Indianapolis, IN, 46202, USA
| | - Qing Yu
- Department of Surgery, Indiana University School of Medicine, 950 W. Walnut Street, R2 E319, Indianapolis, IN, 46202, USA
| | - Caroline Miller
- Electron Microscopy Center, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Kanhaiya Singh
- Department of Surgery, Indiana University School of Medicine, 950 W. Walnut Street, R2 E319, Indianapolis, IN, 46202, USA.,Indiana Center for Regenerative Medicine and Engineering, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Chandan K Sen
- Department of Surgery, Indiana University School of Medicine, 950 W. Walnut Street, R2 E319, Indianapolis, IN, 46202, USA.,Indiana Center for Regenerative Medicine and Engineering, Indiana University School of Medicine, Indianapolis, IN, USA
| |
Collapse
|
39
|
Myocardial Adaptation in Pseudohypoxia: Signaling and Regulation of mPTP via Mitochondrial Connexin 43 and Cardiolipin. Cells 2019; 8:cells8111449. [PMID: 31744200 PMCID: PMC6912244 DOI: 10.3390/cells8111449] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 11/15/2019] [Indexed: 12/26/2022] Open
Abstract
Therapies intended to mitigate cardiovascular complications cannot be applied in practice without detailed knowledge of molecular mechanisms. Mitochondria, as the end-effector of cardioprotection, represent one of the possible therapeutic approaches. The present review provides an overview of factors affecting the regulation processes of mitochondria at the level of mitochondrial permeability transition pores (mPTP) resulting in comprehensive myocardial protection. The regulation of mPTP seems to be an important part of the mechanisms for maintaining the energy equilibrium of the heart under pathological conditions. Mitochondrial connexin 43 is involved in the regulation process by inhibition of mPTP opening. These individual cardioprotective mechanisms can be interconnected in the process of mitochondrial oxidative phosphorylation resulting in the maintenance of adenosine triphosphate (ATP) production. In this context, the degree of mitochondrial membrane fluidity appears to be a key factor in the preservation of ATP synthase rotation required for ATP formation. Moreover, changes in the composition of the cardiolipin’s structure in the mitochondrial membrane can significantly affect the energy system under unfavorable conditions. This review aims to elucidate functional and structural changes of cardiac mitochondria subjected to preconditioning, with an emphasis on signaling pathways leading to mitochondrial energy maintenance during partial oxygen deprivation.
Collapse
|
40
|
Mitochondrial Structural Changes in the Pathogenesis of Diabetic Retinopathy. J Clin Med 2019; 8:jcm8091363. [PMID: 31480638 PMCID: PMC6780143 DOI: 10.3390/jcm8091363] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 08/27/2019] [Accepted: 08/29/2019] [Indexed: 12/24/2022] Open
Abstract
At the core of proper mitochondrial functionality is the maintenance of its structure and morphology. Physical changes in mitochondrial structure alter metabolic pathways inside mitochondria, affect mitochondrial turnover, disturb mitochondrial dynamics, and promote mitochondrial fragmentation, ultimately triggering apoptosis. In high glucose condition, increased mitochondrial fragmentation contributes to apoptotic death in retinal vascular and Müller cells. Although alterations in mitochondrial morphology have been detected in several diabetic tissues, it remains to be established in the vascular cells of the diabetic retina. From a mechanistic standpoint, our current work supports the notion that increased expression of fission genes and decreased expression of fusion genes are involved in promoting excessive mitochondrial fragmentation. While mechanistic insights are only beginning to reveal how high glucose alters mitochondrial morphology, the consequences are clearly seen as release of cytochrome c from fragmented mitochondria triggers apoptosis. Current findings raise the prospect of targeting excessive mitochondrial fragmentation as a potential therapeutic strategy for treatment of diabetic retinopathy. While biochemical and epigenetic changes have been reported to be associated with mitochondrial dysfunction, this review focuses on alterations in mitochondrial morphology, and their impact on mitochondrial function and pathogenesis of diabetic retinopathy.
Collapse
|
41
|
Naryzhnaya NV, Maslov LN, Oeltgen PR. Pharmacology of mitochondrial permeability transition pore inhibitors. Drug Dev Res 2019; 80:1013-1030. [DOI: 10.1002/ddr.21593] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 08/08/2019] [Accepted: 08/12/2019] [Indexed: 12/13/2022]
Affiliation(s)
- Natalia V. Naryzhnaya
- Laboratory of Experimental CardiologyCardiology Research Institute, Tomsk National Research Medical Center of the Russian Academy of Science Tomsk Russia
| | - Leonid N. Maslov
- Laboratory of Experimental CardiologyCardiology Research Institute, Tomsk National Research Medical Center of the Russian Academy of Science Tomsk Russia
| | - Peter R. Oeltgen
- Department of PathologyUniversity of Kentucky College of Medicine Lexington Kentucky
| |
Collapse
|
42
|
Jiang J, Hoagland D, Palatinus JA, He H, Iyyathurai J, Jourdan LJ, Bultynck G, Wang Z, Zhang Z, Schey K, Poelzing S, McGowan FX, Gourdie RG. Interaction of α Carboxyl Terminus 1 Peptide With the Connexin 43 Carboxyl Terminus Preserves Left Ventricular Function After Ischemia-Reperfusion Injury. J Am Heart Assoc 2019; 8:e012385. [PMID: 31422747 PMCID: PMC6759879 DOI: 10.1161/jaha.119.012385] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Background α Carboxyl terminus 1 (αCT1) is a 25–amino acid therapeutic peptide incorporating the zonula occludens‐1 (ZO‐1)–binding domain of connexin 43 (Cx43) that is currently in phase 3 clinical testing on chronic wounds. In mice, we reported that αCT1 reduced arrhythmias after cardiac injury, accompanied by increases in protein kinase Cε phosphorylation of Cx43 at serine 368. Herein, we characterize detailed molecular mode of action of αCT1 in mitigating cardiac ischemia‐reperfusion injury. Methods and Results To study αCT1‐mediated increases in phosphorylation of Cx43 at serine 368, we undertook mass spectrometry of protein kinase Cε phosphorylation assay reactants. This indicated potential interaction between negatively charged residues in the αCT1 Asp‐Asp‐Leu‐Glu‐Iso sequence and lysines (Lys345, Lys346) in an α‐helical sequence (helix 2) within the Cx43‐CT. In silico modeling provided further support for this interaction, indicating that αCT1 may interact with both Cx43 and ZO‐1. Using surface plasmon resonance, thermal shift, and phosphorylation assays, we characterized a series of αCT1 variants, identifying peptides that interacted with either ZO‐1–postsynaptic density‐95/disks large/zonula occludens‐1 2 or Cx43‐CT, but with limited or no ability to bind both molecules. Only peptides competent to interact with Cx43‐CT, but not ZO‐1–postsynaptic density‐95/disks large/zonula occludens‐1 2 alone, prompted increased pS368 phosphorylation. Moreover, in an ex vivo mouse model of ischemia‐reperfusion injury, preischemic infusion only with those peptides competent to bind Cx43 preserved ventricular function after ischemia‐reperfusion. Interestingly, a short 9–amino acid variant of αCT1 (αCT11) demonstrated potent cardioprotective effects when infused either before or after ischemic injury. Conclusions Interaction of αCT1 with the Cx43, but not ZO‐1, is correlated with cardioprotection. Pharmacophores targeting Cx43‐CT could provide a translational approach to preserving heart function after ischemic injury.
Collapse
Affiliation(s)
- Jingbo Jiang
- Fralin Biomedical Research Institute at Virginia Tech Carilion Center for Heart and Reparative Medicine Research Virginia Tech Blacksburg VA.,Shenzhen Children's Hospital Shenzhen China.,Department of Pediatric Cardiology Guangdong Cardiovascular Institute Guangdong General Hospital Guangdong Academy of Medical Sciences Guangzhou China
| | - Daniel Hoagland
- Fralin Biomedical Research Institute at Virginia Tech Carilion Center for Heart and Reparative Medicine Research Virginia Tech Blacksburg VA
| | - Joseph A Palatinus
- Cedars-Sinai Heart Smidt Institute Cedars-Sinai Medical Center Los Angeles CA
| | - Huamei He
- Department of Anesthesiology and Critical Care Medicine Children's Hospital of Philadelphia and University of Pennsylvania Philadelphia PA
| | - Jegan Iyyathurai
- Department Cellular and Molecular Medicine KU Leuven Laboratory of Molecular and Cellular Signaling Leuven Belgium
| | - L Jane Jourdan
- Fralin Biomedical Research Institute at Virginia Tech Carilion Center for Heart and Reparative Medicine Research Virginia Tech Blacksburg VA
| | - Geert Bultynck
- Department Cellular and Molecular Medicine KU Leuven Laboratory of Molecular and Cellular Signaling Leuven Belgium
| | - Zhen Wang
- Department of Biochemistry Vanderbilt University School of Medicine Nashville TN
| | - Zhiwei Zhang
- Department of Pediatric Cardiology Guangdong Cardiovascular Institute Guangdong General Hospital Guangdong Academy of Medical Sciences Guangzhou China
| | - Kevin Schey
- Department of Biochemistry Vanderbilt University School of Medicine Nashville TN
| | - Steven Poelzing
- Fralin Biomedical Research Institute at Virginia Tech Carilion Center for Heart and Reparative Medicine Research Virginia Tech Blacksburg VA.,Department of Biomedical Engineering and Mechanics Virginia Tech Blacksburg VA
| | - Francis X McGowan
- Department of Anesthesiology and Critical Care Medicine Children's Hospital of Philadelphia and University of Pennsylvania Philadelphia PA
| | - Robert G Gourdie
- Fralin Biomedical Research Institute at Virginia Tech Carilion Center for Heart and Reparative Medicine Research Virginia Tech Blacksburg VA.,Department of Biomedical Engineering and Mechanics Virginia Tech Blacksburg VA
| |
Collapse
|
43
|
Martins-Marques T, Ribeiro-Rodrigues T, Batista-Almeida D, Aasen T, Kwak BR, Girao H. Biological Functions of Connexin43 Beyond Intercellular Communication. Trends Cell Biol 2019; 29:835-847. [PMID: 31358412 DOI: 10.1016/j.tcb.2019.07.001] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 06/27/2019] [Accepted: 07/01/2019] [Indexed: 12/13/2022]
Abstract
Connexin43 (Cx43) is commonly associated with direct cell-cell communication through gap junctions (GJs). However, recent groundbreaking studies have challenged this dogma, implicating Cx43 in other biological processes, such as transcription, metabolism, autophagy, and ion channel trafficking. How Cx43 participates in these processes remains largely unknown, although its high turnover rate, capacity to bind to myriad proteins, and the discovery of truncated isoforms of Cx43, ascribe to this protein unanticipated roles in chief processes that require fine-tuned regulation. Accordingly, Cx43 can be regarded as a central integrative hub to which diverse cues converge to be processed in a concerted manner. In this review, we examine the noncanonical roles of Cx43 and discuss the implications of these functions in human diseases and future therapeutic strategies.
Collapse
Affiliation(s)
- Tania Martins-Marques
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal; CNC.IBILI, University of Coimbra, Portugal
| | - Teresa Ribeiro-Rodrigues
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal; CNC.IBILI, University of Coimbra, Portugal
| | - Daniela Batista-Almeida
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal; CNC.IBILI, University of Coimbra, Portugal
| | - Trond Aasen
- Translational Molecular Pathology, Vall d'Hebron Institute of Research (VHIR), Autonomous University of Barcelona, CIBERONC, Barcelona, Spain
| | - Brenda R Kwak
- Department of Pathology and Immunology, University of Geneva, CH-1211 Geneva, Switzerland
| | - Henrique Girao
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal; CNC.IBILI, University of Coimbra, Portugal.
| |
Collapse
|
44
|
Grewal AK, Singh N, Singh TG. Neuroprotective effect of pharmacological postconditioning on cerebral ischaemia-reperfusion-induced injury in mice. ACTA ACUST UNITED AC 2019; 71:956-970. [PMID: 30809806 DOI: 10.1111/jphp.13073] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 01/01/2019] [Indexed: 12/31/2022]
Abstract
OBJECTIVES To investigate the mechanism of neuroprotection rendered via pharmacological postconditioning in cerebral ischaemia-reperfusion-induced injury in mice. METHODS Pharmacological postconditioning is strategy which either involves hindering deleterious pathway or inducing modest stress level which triggers intracellular defence pathway to sustain more vigorous insult leading to conditioning. Hence, in current research we explored the potentiality of CGS21680 (0.5 mg/kg; i.p), an adenosine A2 A receptor agonist and PTEN inhibitor, SF1670 (3 mg/kg; i.p.) to trigger postconditioning after inducing cerebral global ischaemia (17 min) and reperfusion (24 h)-induced injury via occlusion of both carotid arteries. Mice were also given treatment with LY294002 (1.5 mg/kg; i.p.), a PI3K inhibitor and adenosine A2 A receptor antagonist, Istradefylline (2 mg/kg; i.p.), to establish the precise mechanism of postconditioning. Various biochemical and behavioural parameters were assessed to examine the effect of pharmacological postconditioning. KEY FINDINGS Pharmacological postconditioning induced with CGS21680 and SF1670 attenuated the infarction along with improved behavioural and biochemical parameters in comparison with ischaemia-reperfusion control group. The outcome of postconditioning with CGS21680 and SF1670 was significantly reversed by LY294002 and Istradefylline, respectively. CONCLUSIONS The neuroprotective effects of CGS21680 and SF1670 postconditioning on cerebral ischaemia-reperfusion injury may be due to PI3K/Akt pathway activation.
Collapse
Affiliation(s)
- Amarjot Kaur Grewal
- Department of Pharmacology, Chitkara college of Pharmacy, Chitkara University, Patiala, India
| | - Nirmal Singh
- Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala, India
| | - Thakur Gurjeet Singh
- Department of Pharmacology, Chitkara college of Pharmacy, Chitkara University, Patiala, India
| |
Collapse
|
45
|
Du X, Qian C, Jin X. Effects of Mitochondrial DNA Deletion and OSW-1 on PI3K-AKT Signaling Pathway PCR Array in SK-Hep1 Cells. Chin Med 2019. [DOI: 10.4236/cm.2019.103006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
46
|
Bell CL, Shakespeare TI, Smith AR, Murray SA. Visualization of Annular Gap Junction Vesicle Processing: The Interplay Between Annular Gap Junctions and Mitochondria. Int J Mol Sci 2018; 20:ijms20010044. [PMID: 30583492 PMCID: PMC6337258 DOI: 10.3390/ijms20010044] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 12/15/2018] [Accepted: 12/20/2018] [Indexed: 11/16/2022] Open
Abstract
It is becoming clear that in addition to gap junctions playing a role in cell⁻cell communication, gap junction proteins (connexins) located in cytoplasmic compartments may have other important functions. Mitochondrial connexin 43 (Cx43) is increased after ischemic preconditioning and has been suggested to play a protective role in the heart. How Cx43 traffics to the mitochondria and the interactions of mitochondria with other Cx43-containing structures are unclear. In this study, immunocytochemical, super-resolution, and transmission electron microscopy were used to detect cytoplasmic Cx43-containing structures and to demonstrate their interactions with other cytoplasmic organelles. The most prominent cytoplasmic Cx43-containing structures-annular gap junctions-were demonstrated to form intimate associations with lysosomes as well as with mitochondria. Surprisingly, the frequency of associations between mitochondria and annular gap junctions was greater than that between lysosomes and annular gap junctions. The benefits of annular gap junction/mitochondrial associations are not known. However, it is tempting to suggest, among other possibilities, that the contact between annular gap junction vesicles and mitochondria facilitates Cx43 delivery to the mitochondria. Furthermore, it points to the need for investigating annular gap junctions as more than only vesicles destined for degradation.
Collapse
Affiliation(s)
- Cheryl L Bell
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA.
| | | | - Amber R Smith
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA.
| | - Sandra A Murray
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA.
| |
Collapse
|
47
|
Basheer WA, Fu Y, Shimura D, Xiao S, Agvanian S, Hernandez DM, Hitzeman TC, Hong T, Shaw RM. Stress response protein GJA1-20k promotes mitochondrial biogenesis, metabolic quiescence, and cardioprotection against ischemia/reperfusion injury. JCI Insight 2018; 3:121900. [PMID: 30333316 DOI: 10.1172/jci.insight.121900] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 09/11/2018] [Indexed: 01/23/2023] Open
Abstract
Connexin 43 (Cx43), a product of the GJA1 gene, is a gap junction protein facilitating intercellular communication between cardiomyocytes. Cx43 protects the heart from ischemic injury by mechanisms that are not well understood. GJA1 mRNA can undergo alternative translation, generating smaller isoforms in the heart, with GJA1-20k being the most abundant. Here, we report that ischemic and ischemia/reperfusion (I/R) injuries upregulate endogenous GJA1-20k protein in the heart, which targets to cardiac mitochondria and associates with the outer mitochondrial membrane. Exploring the functional consequence of increased GJA1-20k, we found that AAV9-mediated gene transfer of GJA1-20k in mouse hearts increases mitochondrial biogenesis while reducing mitochondrial membrane potential, respiration, and ROS production. By doing so, GJA1-20k promotes a protective mitochondrial phenotype, as seen with ischemic preconditioning (IPC), which also increases endogenous GJA1-20k in heart lysates and mitochondrial fractions. As a result, AAV9-GJA1-20k pretreatment reduces myocardial infarct size in mouse hearts subjected to in vivo ischemic injury or ex vivo I/R injury, similar to an IPC-induced cardioprotective effect. In conclusion, GJA1-20k is an endogenous stress response protein that induces mitochondrial biogenesis and metabolic hibernation, preconditioning the heart against I/R insults. Introduction of exogenous GJA1-20k is a putative therapeutic strategy for patients undergoing anticipated ischemic injury.
Collapse
Affiliation(s)
- Wassim A Basheer
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Ying Fu
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Daisuke Shimura
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Shaohua Xiao
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Sosse Agvanian
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Diana M Hernandez
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Tara C Hitzeman
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - TingTing Hong
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA.,Department of Medicine, Cedars-Sinai Medical Center and UCLA, Los Angeles, California
| | - Robin M Shaw
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California, USA.,Department of Medicine, Cedars-Sinai Medical Center and UCLA, Los Angeles, California
| |
Collapse
|
48
|
A Cell Junctional Protein Network Associated with Connexin-26. Int J Mol Sci 2018; 19:ijms19092535. [PMID: 30150563 PMCID: PMC6163694 DOI: 10.3390/ijms19092535] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 08/20/2018] [Accepted: 08/21/2018] [Indexed: 02/06/2023] Open
Abstract
GJB2 mutations are the leading cause of non-syndromic inherited hearing loss. GJB2 encodes connexin-26 (CX26), which is a connexin (CX) family protein expressed in cochlea, skin, liver, and brain, displaying short cytoplasmic N-termini and C-termini. We searched for CX26 C-terminus binding partners by affinity capture and identified 12 unique proteins associated with cell junctions or cytoskeleton (CGN, DAAM1, FLNB, GAPDH, HOMER2, MAP7, MAPRE2 (EB2), JUP, PTK2B, RAI14, TJP1, and VCL) by using mass spectrometry. We show that, similar to other CX family members, CX26 co-fractionates with TJP1, VCL, and EB2 (EB1 paralogue) as well as the membrane-associated protein ASS1. The adaptor protein CGN (cingulin) co-immuno-precipitates with CX26, ASS1, and TJP1. In addition, CGN co-immunoprecipitation with CX30, CX31, and CX43 indicates that CX association is independent on the CX C-terminus length or sequence. CX26, CGN, FLNB, and DAMM1 were shown to distribute to the organ of Corti and hepatocyte plasma membrane. In the mouse liver, CX26 and TJP1 co-localized at the plasma membrane. In conclusion, CX26 associates with components of other membrane junctions that integrate with the cytoskeleton.
Collapse
|
49
|
Wörsdörfer P, Wagner N, Ergün S. The role of connexins during early embryonic development: pluripotent stem cells, gene editing, and artificial embryonic tissues as tools to close the knowledge gap. Histochem Cell Biol 2018; 150:327-339. [PMID: 30039329 DOI: 10.1007/s00418-018-1697-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/17/2018] [Indexed: 12/14/2022]
Abstract
Since almost 4 decades, connexins have been discussed as important regulators of embryogenesis. Several different members of the gene family can be detected in the preimplantation embryo and during gastrulation. However, genetically engineered mice deficient for every connexin expressed during early development are available and even double-deficient mice were generated. Interestingly, all of these mice complete gastrulation without any abnormalities. This raises the question if the role of connexins has been overrated or if other gene family members compensate and mask their importance. To answer this question, embryos completely devoid of any gap junctional communication need to be investigated. This is challenging because a variety of connexin genes are co-expressed and some null mutations lead to a lethal phenotype. In addition, maternal connexin transcripts were described to persist until the blastocyst stage. In this review, we summarize the current knowledge about the role of connexins during preimplantation development and in embryonic stem cells. We propose that the use of pluripotent stem cells, trophoblast stem cells, as well as artificial embryo-like structures and organoid cultures in combination with multiplex CRISPR/Cas9-based genome editing provides a powerful platform to comprehensively readdress this issue and decipher the role of connexins during lineage decision, differentiation, and morphogenesis in a cell culture model for mouse and human development.
Collapse
Affiliation(s)
- Philipp Wörsdörfer
- Institute of Anatomy and Cell Biology, University of Würzburg, Koellikerstr.6, 97070, Würzburg, Germany.
| | - Nicole Wagner
- Institute of Anatomy and Cell Biology, University of Würzburg, Koellikerstr.6, 97070, Würzburg, Germany
| | - Süleyman Ergün
- Institute of Anatomy and Cell Biology, University of Würzburg, Koellikerstr.6, 97070, Würzburg, Germany
| |
Collapse
|
50
|
Abstract
Several interventions, such as ischemic preconditioning, remote pre/perconditioning, or postconditioning, are known to decrease lethal myocardial ischemia-reperfusion injury. While several signal transduction pathways become activated by such maneuvers, they all have a common end point, namely, the mitochondria. These organelles represent an essential target of the cardioprotective strategies, and the preservation of mitochondrial function is central for the reduction of ischemia-reperfusion injury. In the present review, we address the role of mitochondria in the different conditioning strategies; in particular, we focus on alterations of mitochondrial function in terms of energy production, formation of reactive oxygen species, opening of the mitochondrial permeability transition pore, and mitochondrial dynamics induced by ischemia-reperfusion.
Collapse
Affiliation(s)
- Kerstin Boengler
- Institute of Physiology, Justus-Liebig Universität , Giessen , Germany
| | - Günter Lochnit
- Institute of Biochemistry, Justus-Liebig Universität , Giessen , Germany
| | - Rainer Schulz
- Institute of Physiology, Justus-Liebig Universität , Giessen , Germany
| |
Collapse
|