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Targeting T-type channels in cancer: What is on and what is off? Drug Discov Today 2021; 27:743-758. [PMID: 34838727 DOI: 10.1016/j.drudis.2021.11.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 10/10/2021] [Accepted: 11/18/2021] [Indexed: 12/27/2022]
Abstract
Over the past 20 years, various studies have demonstrated a pivotal role of T-type calcium channels (TTCCs) in tumor progression. Cytotoxic effects of TTCC pharmacological blockers have been reported in vitro and in preclinical models. However, their roles in cancer physiology are only beginning to be understood. In this review, we discuss evidence for the signaling pathways and cellular processes stemming from TTCC activity, mainly inferred by inverse reasoning from pharmacological blocks and, only in a few studies, by gene silencing or channel activation. A thorough analysis indicates that drug-induced cytotoxicity is partially an off-target effect. Dissection of on/off-target activity is paramount to elucidate the physiological roles of TTCCs, and to deliver efficacious therapies suited to different cancer types and stages.
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Nishimura A, Shimauchi T, Tanaka T, Shimoda K, Toyama T, Kitajima N, Ishikawa T, Shindo N, Numaga-Tomita T, Yasuda S, Sato Y, Kuwahara K, Kumagai Y, Akaike T, Ide T, Ojida A, Mori Y, Nishida M. Hypoxia-induced interaction of filamin with Drp1 causes mitochondrial hyperfission-associated myocardial senescence. Sci Signal 2018; 11:11/556/eaat5185. [PMID: 30425165 DOI: 10.1126/scisignal.aat5185] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Defective mitochondrial dynamics through aberrant interactions between mitochondria and actin cytoskeleton is increasingly recognized as a key determinant of cardiac fragility after myocardial infarction (MI). Dynamin-related protein 1 (Drp1), a mitochondrial fission-accelerating factor, is activated locally at the fission site through interactions with actin. Here, we report that the actin-binding protein filamin A acted as a guanine nucleotide exchange factor for Drp1 and mediated mitochondrial fission-associated myocardial senescence in mice after MI. In peri-infarct regions characterized by mitochondrial hyperfission and associated with myocardial senescence, filamin A colocalized with Drp1 around mitochondria. Hypoxic stress induced the interaction of filamin A with the GTPase domain of Drp1 and increased Drp1 activity in an actin-binding-dependent manner in rat cardiomyocytes. Expression of the A1545T filamin mutant, which potentiates actin aggregation, promoted mitochondrial hyperfission under normoxia. Furthermore, pharmacological perturbation of the Drp1-filamin A interaction by cilnidipine suppressed mitochondrial hyperfission-associated myocardial senescence and heart failure after MI. Together, these data demonstrate that Drp1 association with filamin and the actin cytoskeleton contributes to cardiac fragility after MI and suggests a potential repurposing of cilnidipine, as well as provides a starting point for innovative Drp1 inhibitor development.
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Affiliation(s)
- Akiyuki Nishimura
- National Institute for Physiological Sciences (NIPS), National Institutes of Natural Sciences, Aichi 444-8787, Japan.,Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Aichi 444-8787, Japan.,SOKENDAI (School of Life Science, The Graduate University for Advanced Studies), Aichi 444-8787, Japan.,Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Tsukasa Shimauchi
- National Institute for Physiological Sciences (NIPS), National Institutes of Natural Sciences, Aichi 444-8787, Japan.,Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Aichi 444-8787, Japan.,Kyushu University Graduate School of Medical Sciences, Fukuoka 812-8582, Japan
| | - Tomohiro Tanaka
- National Institute for Physiological Sciences (NIPS), National Institutes of Natural Sciences, Aichi 444-8787, Japan.,Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Aichi 444-8787, Japan
| | - Kakeru Shimoda
- National Institute for Physiological Sciences (NIPS), National Institutes of Natural Sciences, Aichi 444-8787, Japan.,Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Aichi 444-8787, Japan.,SOKENDAI (School of Life Science, The Graduate University for Advanced Studies), Aichi 444-8787, Japan
| | - Takashi Toyama
- National Institute for Physiological Sciences (NIPS), National Institutes of Natural Sciences, Aichi 444-8787, Japan.,Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan.,Faculty of Medicine, University of Tsukuba, Tsukuba 305-8575, Japan
| | - Naoyuki Kitajima
- National Institute for Physiological Sciences (NIPS), National Institutes of Natural Sciences, Aichi 444-8787, Japan.,Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Tatsuya Ishikawa
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan.,EA Pharma Co. Inc., Tokyo 104-0042, Japan
| | - Naoya Shindo
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Takuro Numaga-Tomita
- National Institute for Physiological Sciences (NIPS), National Institutes of Natural Sciences, Aichi 444-8787, Japan.,Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Aichi 444-8787, Japan.,SOKENDAI (School of Life Science, The Graduate University for Advanced Studies), Aichi 444-8787, Japan
| | - Satoshi Yasuda
- National Institute of Health Sciences, Kanagawa 210-9501, Japan
| | - Yoji Sato
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan.,National Institute of Health Sciences, Kanagawa 210-9501, Japan
| | | | - Yoshito Kumagai
- Faculty of Medicine, University of Tsukuba, Tsukuba 305-8575, Japan
| | - Takaaki Akaike
- Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Tomomi Ide
- Kyushu University Graduate School of Medical Sciences, Fukuoka 812-8582, Japan
| | - Akio Ojida
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Yasuo Mori
- Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Motohiro Nishida
- National Institute for Physiological Sciences (NIPS), National Institutes of Natural Sciences, Aichi 444-8787, Japan. .,Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, Aichi 444-8787, Japan.,SOKENDAI (School of Life Science, The Graduate University for Advanced Studies), Aichi 444-8787, Japan.,Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
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Wan F, Letavernier E, Le Saux CJ, Houssaini A, Abid S, Czibik G, Sawaki D, Marcos E, Dubois-Rande JL, Baud L, Adnot S, Derumeaux G, Gellen B. Calpastatin overexpression impairs postinfarct scar healing in mice by compromising reparative immune cell recruitment and activation. Am J Physiol Heart Circ Physiol 2015; 309:H1883-93. [PMID: 26453333 DOI: 10.1152/ajpheart.00594.2015] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 10/03/2015] [Indexed: 12/15/2022]
Abstract
The activation of the calpain system is involved in the repair process following myocardial infarction (MI). However, the impact of the inhibition of calpain by calpastatin, its natural inhibitor, on scar healing and left ventricular (LV) remodeling is elusive. Male mice ubiquitously overexpressing calpastatin (TG) and wild-type (WT) controls were subjected to an anterior coronary artery ligation. Mortality at 6 wk was higher in TG mice (24% in WT vs. 44% in TG, P < 0.05) driven by a significantly higher incidence of cardiac rupture during the first week post-MI, despite comparable infarct size and LV dysfunction and dilatation. Calpain activation post-MI was blunted in TG myocardium. In TG mice, inflammatory cell infiltration and activation were reduced in the infarct zone (IZ), particularly affecting M2 macrophages and CD4(+) T cells, which are crucial for scar healing. To elucidate the role of calpastatin overexpression in macrophages, we stimulated peritoneal macrophages obtained from TG and WT mice in vitro with IL-4, yielding an abrogated M2 polarization in TG but not in WT cells. Lymphopenic Rag1(-/-) mice receiving TG splenocytes before MI demonstrated decreased T-cell recruitment and M2 macrophage activation in the IZ day 5 after MI compared with those receiving WT splenocytes. Calpastatin overexpression prevented the activation of the calpain system after MI. It also impaired scar healing, promoted LV rupture, and increased mortality. Defective scar formation was associated with blunted CD4(+) T-cell and M2-macrophage recruitment.
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Affiliation(s)
- Feng Wan
- Institut National de la Santé et de la Recherche Médicale U955, Université Paris-Est Creteil, Créteil, France
| | - Emmanuel Letavernier
- Department of Physiology, Assistance Publique-Hôpitaux de Paris (AP-HP), Tenon Hospital, Paris, France; Inflammation-Immunopathology-Biotherapy Department (DHU i2B), F-75020, Sorbonne Universités, Université Pierre et Marie Curie, Université Paris 06, Unités Mixtes de Recherche Scientifique 1155, Paris, France; and
| | - Claude Jourdan Le Saux
- Department of Medicine/Cardiology Division, University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - Amal Houssaini
- Institut National de la Santé et de la Recherche Médicale U955, Université Paris-Est Creteil, Créteil, France
| | - Shariq Abid
- Institut National de la Santé et de la Recherche Médicale U955, Université Paris-Est Creteil, Créteil, France
| | - Gabor Czibik
- Institut National de la Santé et de la Recherche Médicale U955, Université Paris-Est Creteil, Créteil, France
| | - Daigo Sawaki
- Institut National de la Santé et de la Recherche Médicale U955, Université Paris-Est Creteil, Créteil, France
| | - Elisabeth Marcos
- Institut National de la Santé et de la Recherche Médicale U955, Université Paris-Est Creteil, Créteil, France
| | - Jean-Luc Dubois-Rande
- Institut National de la Santé et de la Recherche Médicale U955, Université Paris-Est Creteil, Créteil, France; Département Hospitalo-Universitairé Ageing Thorax-Vessels Blood (DHU A-TVB), Department of Physiology, AP-HP, Henri Mondor Hospital, Créteil, France; DHU A-TVB, Department of Cardiology, AP-HP, Henri Mondor Hospital, Créteil, France
| | - Laurent Baud
- Department of Physiology, Assistance Publique-Hôpitaux de Paris (AP-HP), Tenon Hospital, Paris, France; Inflammation-Immunopathology-Biotherapy Department (DHU i2B), F-75020, Sorbonne Universités, Université Pierre et Marie Curie, Université Paris 06, Unités Mixtes de Recherche Scientifique 1155, Paris, France; and
| | - Serge Adnot
- Institut National de la Santé et de la Recherche Médicale U955, Université Paris-Est Creteil, Créteil, France; Département Hospitalo-Universitairé Ageing Thorax-Vessels Blood (DHU A-TVB), Department of Physiology, AP-HP, Henri Mondor Hospital, Créteil, France
| | - Geneviève Derumeaux
- Institut National de la Santé et de la Recherche Médicale U955, Université Paris-Est Creteil, Créteil, France; Département Hospitalo-Universitairé Ageing Thorax-Vessels Blood (DHU A-TVB), Department of Physiology, AP-HP, Henri Mondor Hospital, Créteil, France
| | - Barnabas Gellen
- Institut National de la Santé et de la Recherche Médicale U955, Université Paris-Est Creteil, Créteil, France; DHU A-TVB, Department of Cardiology, AP-HP, Henri Mondor Hospital, Créteil, France; Department of Cardiology, Poitiers University Hospital, F-86000, Poitiers, France
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4
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Cendes F, Sakamoto AC, Spreafico R, Bingaman W, Becker AJ. Epilepsies associated with hippocampal sclerosis. Acta Neuropathol 2014; 128:21-37. [PMID: 24823761 DOI: 10.1007/s00401-014-1292-0] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 05/05/2014] [Accepted: 05/06/2014] [Indexed: 01/22/2023]
Abstract
Hippocampal sclerosis (HS) is considered the most frequent neuropathological finding in patients with mesial temporal lobe epilepsy (MTLE). Hippocampal specimens of pharmacoresistant MTLE patients that underwent epilepsy surgery for seizure control reveal the characteristic pattern of segmental neuronal cell loss and concomitant astrogliosis. However, classification issues of hippocampal lesion patterns have been a matter of intense debate. International consensus classification has only recently provided significant progress for comparisons of neurosurgical and clinic-pathological series between different centers. The respective four-tiered classification system of the International League Against Epilepsy subdivides HS into three types and includes a term of "gliosis only, no-HS". Future studies will be necessary to investigate whether each of these subtypes of HS may be related to different etiological factors or with postoperative memory and seizure outcome. Molecular studies have provided potential deeper insights into the pathogenesis of HS and MTLE on the basis of epilepsy-surgical hippocampal specimens and corresponding animal models. These include channelopathies, activation of NMDA receptors, and other conditions related to Ca(2+) influx into neurons, the imbalance of Ca(2+)-binding proteins, acquired channelopathies that increase neuronal excitability, paraneoplastic and non-paraneoplastic inflammatory events, and epigenetic regulation promoting or facilitating hippocampal epileptogenesis. Genetic predisposition for HS is clearly suggested by the high incidence of family history in patients with HS, and by familial MTLE with HS. So far, it is clear that HS is multifactorial and there is no individual pathogenic factor either necessary or sufficient to generate this intriguing histopathological condition. The obvious variety of pathogenetic combinations underlying HS may explain the multitude of clinical presentations, different responses to clinical and surgical treatment. We believe that the stratification of neuropathological patterns can help to characterize specific clinic-pathological entities and predict the postsurgical seizure control in an improved fashion.
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5
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Rice RA, Berchtold NC, Cotman CW, Green KN. Age-related downregulation of the CaV3.1 T-type calcium channel as a mediator of amyloid beta production. Neurobiol Aging 2013; 35:1002-11. [PMID: 24268883 DOI: 10.1016/j.neurobiolaging.2013.10.090] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Revised: 10/07/2013] [Accepted: 10/25/2013] [Indexed: 11/25/2022]
Abstract
Alzheimer's is a crippling neurodegenerative disease that largely affects aged individuals. Decades of research have highlighted age-related changes in calcium homeostasis that occur before and throughout the duration of the disease, and the contributions of such dysregulation to Alzheimer's disease pathogenesis. We report an age-related decrease in expression of the CaV3.1 T-type calcium channel at the level of messenger RNA and protein in both humans and mice that is exacerbated with the presence of Alzheimer's disease. Downregulating T-type calcium channels in N2a cells and the 3xTg-AD mouse model of Alzheimer's disease, by way of pharmacologic inhibition with NNC-55-0396, results in a rapid increase in amyloid beta production via reductions in non-amyloidogenic processing, whereas genetic overexpression of the channel in human embryonic kidney cells expressing amyloid precursor protein produces complementary effects. The age-related decline in CaV3.1 expression may therefore contribute to a pro-amyloidogenic environment in the aging brain and represents a novel opportunity to intervene in the course of Alzheimer's disease pathogenesis.
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Affiliation(s)
- Rachel A Rice
- Department of Neurobiology and Behavior, Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA, USA
| | - Nicole C Berchtold
- Department of Neurobiology and Behavior, Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA, USA
| | - Carl W Cotman
- Department of Neurobiology and Behavior, Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA, USA
| | - Kim N Green
- Department of Neurobiology and Behavior, Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA, USA.
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6
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Protective effects of adenosine on the diabetic myocardium against ischemia–reperfusion injury: Role of calpain. Med Hypotheses 2012; 79:462-4. [DOI: 10.1016/j.mehy.2012.06.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Revised: 06/12/2012] [Accepted: 06/21/2012] [Indexed: 11/17/2022]
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7
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Zhang Y, Zhong N, Zhou ZN. Effects of Chronic Intermittent Hypobaric Hypoxia on the L-type Calcium Current in Rat Ventricular Myocytes. High Alt Med Biol 2010; 11:61-7. [DOI: 10.1089/ham.2009.1011] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Yi Zhang
- Department of Physiology, Hebei Medical University, Shijiazhuang, China
| | - Ning Zhong
- Gladstone Institutes of Cardiovascular and Neurological Diseases, University of California, San Francisco, California, USA
| | - Zhao-Nian Zhou
- Laboratory of Hypoxia Physiology, Shanghai Institute of Biological Sciences, Chinese Academy of Science, Shanghai, China
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8
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Sandmann S, Li J, Fritzenkötter C, Spormann J, Tiede K, Fischer JW, Unger T. Differential effects of olmesartan and ramipril on inflammatory response after myocardial infarction in rats. Blood Press 2009; 15:116-28. [PMID: 16754275 DOI: 10.1080/08037050600586593] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
This study compares the effect of two different strategies to inhibit the renin-angiotensin system in the setting of acute myocardial infarction (MI). Male Wistar rats were treated with placebo, the angiotensin-converting enzyme (ACE) inhibitor ramipril (1 mg/kg/day), or the AT1 receptor antagonist, olmesartan (1 mg/kg/day), both initiated 1 week before induction of MI and continued for 6 weeks after MI. The inflammatory reaction in the heart was investigated 7 days post-MI by determination of macrophage infiltration and the expression of tumor necrosis factor (TNF-alpha), interleukin (IL)-1beta and IL-6 at mRNA and protein levels. Six weeks post-MI, cardiac function was measured following chronic implantation of catheters in the LV and femoral artery, and cardiac morphology and coronary structure were investigated in picrosirius-red stained hearts. In placebo-treated rats, macrophage infiltration was accompanied by upregulation of IL-1beta and IL-6 mRNA in the peri-infarct zone. TNF-alpha and IL-1beta mRNA and protein were also upregulated in the non-infarcted myocardium. Whereas both treatment regimes significantly reduced IL-6 upregulation, olmesartan additionally reduced macrophage infiltration and IL-1beta expression. Six weeks post-MI, placebo-treated MI animals developed an impaired cardiac function with structural remodeling of the myocardium and coronaries. While olmesartan and ramipril both improved cardiac function and reduced infarct size and myocardial/coronary remodeling, olmesartan was more effective not only in increasing vascular perimeter, inner vascular diameter and septal thickness but also in lowering media thickness of coronary arteries, inner left ventricular diameter, left ventricular circumference and left ventricular end-diastolic pressure than ramipril. Thus, following MI the AT1 receptor blocker, olmesartan, attenuated cardiac inflammatory reactions and protected myocardial/coronary structure and function of the failing heart proving to be of similar, in some cases superior effectiveness in this respect than the ACE inhibitor, ramipril.
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Affiliation(s)
- Steffen Sandmann
- Center for Cardiovascular Research (CCR)/Institute of Pharmacology and Toxicology, Charité - University Medicine Berlin, Germany
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9
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Neuhof C, Fabiunk V, Speth M, Möller A, Fritz F, Tillmanns H, Neuhof H, Erdogan A. Reduction of myocardial infarction by postischemic administration of the calpain inhibitor A-705253 in comparison to the Na(+)/H(+) exchange inhibitor Cariporide in isolated perfused rabbit hearts. Biol Chem 2009; 389:1505-12. [PMID: 18844452 DOI: 10.1515/bc.2008.172] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The calpain inhibitor A-705253 and the Na(+)/H(+)-exchange inhibitor Cariporide were studied in isolated perfused rabbit hearts subjected to 60 min occlusion of the ramus interventricularis of the left coronary artery (below the origin of the first diagonal branch), followed by 120 min of reperfusion. The inhibitors were added to the perfusion fluid solely or in combination at the beginning of reperfusion. Hemodynamic monitoring and biochemical analysis of perfusion fluid from the coronary outflow were performed. Myocardial infarct size and area at risk (transiently not perfused myocardium) were determined from left ventricular slices after a special staining procedure with Evans blue and 2,3,5-triphenyltetrazolium chloride. The infarcted area (dead myocardium) was 72.7+/-4.0% of the area at risk in untreated controls, but was significantly smaller in the presence of the inhibitors. The largest effect was seen with 10(-6) m A-705253, which reduced the infarcted area to 49.2+/-4.1% of the area at risk, corresponding to a reduction of 33.6%. Cariporide at 10(-6) m reduced the infarct size to the same extent. The combination of both inhibitors, however, did not further improve cardioprotection. No statistical difference was observed between the experimental groups in coronary perfusion, left ventricular pressure, heart rate, and in the release of lactate dehydrogenase and creatin kinase from heart muscle.
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10
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Transcriptional upregulation of Cav3.2 mediates epileptogenesis in the pilocarpine model of epilepsy. J Neurosci 2009; 28:13341-53. [PMID: 19052226 DOI: 10.1523/jneurosci.1421-08.2008] [Citation(s) in RCA: 155] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In both humans and animals, an insult to the brain can lead, after a variable latent period, to the appearance of spontaneous epileptic seizures that persist for life. The underlying processes, collectively referred to as epileptogenesis, include multiple structural and functional neuronal alterations. We have identified the T-type Ca(2+) channel Ca(v)3.2 as a central player in epileptogenesis. We show that a transient and selective upregulation of Ca(v)3.2 subunits on the mRNA and protein levels after status epilepticus causes an increase in cellular T-type Ca(2+) currents and a transitional increase in intrinsic burst firing. These functional changes are absent in mice lacking Ca(v)3.2 subunits. Intriguingly, the development of neuropathological hallmarks of chronic epilepsy, such as subfield-specific neuron loss in the hippocampal formation and mossy fiber sprouting, was virtually completely absent in Ca(v)3.2(-/-) mice. In addition, the appearance of spontaneous seizures was dramatically reduced in these mice. Together, these data establish transcriptional induction of Ca(v)3.2 as a critical step in epileptogenesis and neuronal vulnerability.
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11
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Uemura K, Adachi-Akahane S, Shintani-Ishida K, Yoshida KI. Carbon monoxide protects cardiomyogenic cells against ischemic death through L-type Ca2+ channel inhibition. Biochem Biophys Res Commun 2005; 334:661-8. [PMID: 16023079 DOI: 10.1016/j.bbrc.2005.06.142] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2005] [Accepted: 06/19/2005] [Indexed: 11/24/2022]
Abstract
Carbon monoxide (CO) is known to protect myocardial and vascular cells against injuries due to ischemia-reperfusion or inflammation. We showed that a Ca(2+)-dependent protease calpain promotes necrotic cell death of cardiomyocyte-derived H9c2 cells due to hypoxia through alpha-fodrin proteolysis. Here, we show that ischemia induces necrotic cell death, which is inhibited by either CO, extracellular Ca(2+) deprivation or L-type Ca(2+) channel blockers. A whole cell patch-clamp experiment supports that CO inhibits L-type Ca(2+) channel mediated influx of Ca(2+) and the ischemic death of H9c2 cells.
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Affiliation(s)
- Koichi Uemura
- Department of Forensic Medicine, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
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Lim CC, Zuppinger C, Guo X, Kuster GM, Helmes M, Eppenberger HM, Suter TM, Liao R, Sawyer DB. Anthracyclines induce calpain-dependent titin proteolysis and necrosis in cardiomyocytes. J Biol Chem 2003; 279:8290-9. [PMID: 14676206 DOI: 10.1074/jbc.m308033200] [Citation(s) in RCA: 209] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Titin, the largest myofilament protein, serves as a template for sarcomere assembly and acts as a molecular spring to contribute to diastolic function. Titin is known to be extremely susceptible to calcium-dependent protease degradation in vitro. We hypothesized that titin degradation is an early event in doxorubicin-induced cardiac injury and that titin degradation occurs by activation of the calcium-dependent proteases, the calpains. Treatment of cultured adult rat cardiomyocytes with 1 or 3 micromol/liter doxorubicin for 24 h resulted in degradation of titin in myocyte lysates, which was confirmed by a reduction in immunostaining of an antibody to the spring-like (PEVK) domain of titin at the I-band of the sarcomere. The elastic domain of titin appears to be most susceptible to proteolysis because co-immunostaining with an antibody to titin at the M-line was preserved, suggesting targeted proteolysis of the spring-like domain of titin. Doxorubicin treatment for 1 h resulted in approximately 3-fold increase in calpain activity, which remained elevated at 48 h. Co-treatment with calpain inhibitors resulted in preservation of titin, reduction in myofibrillar disarray, and attenuation of cardiomyocyte necrosis but not apoptosis. Co-treatment with a caspase inhibitor did not prevent the degradation of titin, which precludes caspase-3 as an early mechanism of titin proteolysis. We conclude that calpain activation is an early event after doxorubicin treatment in cardiomyocytes and appears to target the degradation of titin. Proteolysis of the spring-like domain of titin may predispose cardiomyocytes to diastolic dysfunction, myofilament instability, and cell death by necrosis.
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Affiliation(s)
- Chee Chew Lim
- Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts 02118, USA
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