1
|
MDMX elevation by a novel Mdmx-p53 interaction inhibitor mitigates neuronal damage after ischemic stroke. Sci Rep 2022; 12:21110. [PMID: 36473920 PMCID: PMC9726886 DOI: 10.1038/s41598-022-25427-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 11/29/2022] [Indexed: 12/12/2022] Open
Abstract
Mdmx and Mdm2 are two major suppressor factors for the tumor suppressor gene p53. In central nervous system, Mdmx suppresses the transcriptional activity of p53 and enhances the binding of Mdm2 to p53 for degradation. But Mdmx dynamics in cerebral infarction remained obscure. Here we investigated the role of Mdmx under ischemic conditions and evaluated the effects of our developed small-molecule Protein-Protein Interaction (PPI) inhibitors, K-181, on Mdmx-p53 interactions in vivo and in vitro. We found ischemic stroke decreased Mdmx expression with increased phosphorylation of Mdmx Serine 367, while Mdmx overexpression by AAV-Mdmx showed a neuroprotective effect on neurons. The PPI inhibitor, K-181 attenuated the neurological deficits by increasing Mdmx expression in post-stroke mice brain. Additionally, K-181 selectively inhibited HDAC6 activity and enhanced tubulin acetylation. Our findings clarified the dynamics of Mdmx in cerebral ischemia and provide a clue for the future pharmaceutic development of ischemic stroke.
Collapse
|
2
|
Jurcau A, Ardelean AI. Oxidative Stress in Ischemia/Reperfusion Injuries following Acute Ischemic Stroke. Biomedicines 2022; 10:biomedicines10030574. [PMID: 35327376 PMCID: PMC8945353 DOI: 10.3390/biomedicines10030574] [Citation(s) in RCA: 43] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 02/25/2022] [Accepted: 02/28/2022] [Indexed: 02/04/2023] Open
Abstract
Recanalization therapy is increasingly used in the treatment of acute ischemic stroke. However, in about one third of these patients, recanalization is followed by ischemia/reperfusion injuries, and clinically to worsening of the neurological status. Much research has focused on unraveling the involved mechanisms in order to prevent or efficiently treat these injuries. What we know so far is that oxidative stress and mitochondrial dysfunction are significantly involved in the pathogenesis of ischemia/reperfusion injury. However, despite promising results obtained in experimental research, clinical studies trying to interfere with the oxidative pathways have mostly failed. The current article discusses the main mechanisms leading to ischemia/reperfusion injuries, such as mitochondrial dysfunction, excitotoxicity, and oxidative stress, and reviews the clinical trials with antioxidant molecules highlighting recent developments and future strategies.
Collapse
Affiliation(s)
- Anamaria Jurcau
- Department of Psycho-Neurosciences and Rehabilitation, Faculty of Medicine and Pharmacy, University of Oradea, 410087 Oradea, Romania
- Department of Neurology, Clinical Municipal Hospital Oradea, Louis Pasteur Street nr 26, 410054 Oradea, Romania
- Correspondence: ; Tel.: +40-744-600-833
| | - Adriana Ioana Ardelean
- Department of Preclinical Sciences, Faculty of Medicine and Pharmacy, University of Oradea, Universitatii Street nr 1, 410087 Oradea, Romania;
- Department of Cardiology, Clinical Emergency County Hospital Oradea, Gh. Doja Street nr 65, 410169 Oradea, Romania
| |
Collapse
|
3
|
Pluta R, Kiś J, Januszewski S, Jabłoński M, Czuczwar SJ. Cross-Talk between Amyloid, Tau Protein and Free Radicals in Post-Ischemic Brain Neurodegeneration in the Form of Alzheimer’s Disease Proteinopathy. Antioxidants (Basel) 2022; 11:antiox11010146. [PMID: 35052650 PMCID: PMC8772936 DOI: 10.3390/antiox11010146] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 01/05/2022] [Accepted: 01/09/2022] [Indexed: 02/04/2023] Open
Abstract
Recent years have seen remarkable progress in research into free radicals oxidative stress, particularly in the context of post-ischemic recirculation brain injury. Oxidative stress in post-ischemic tissues violates the integrity of the genome, causing DNA damage, death of neuronal, glial and vascular cells, and impaired neurological outcome after brain ischemia. Indeed, it is now known that DNA damage and repair play a key role in post-stroke white and gray matter remodeling, and restoring the integrity of the blood-brain barrier. This review will present one of the newly characterized mechanisms that emerged with genomic and proteomic development that led to brain ischemia to a new level of post-ischemic neuropathological mechanisms, such as the presence of amyloid plaques and the development of neurofibrillary tangles, which further exacerbate oxidative stress. Finally, we hypothesize that modified amyloid and the tau protein, along with the oxidative stress generated, are new key elements in the vicious circle important in the development of post-ischemic neurodegeneration in a type of Alzheimer’s disease proteinopathy.
Collapse
Affiliation(s)
- Ryszard Pluta
- Laboratory of Ischemic and Neurodegenerative Brain Research, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawińskiego 5 Str., 02-106 Warsaw, Poland;
- Correspondence: ; Tel.: +48-22-608-6540
| | - Jacek Kiś
- Department of Urology, 1st Military Clinical Hospital with the Outpatient Clinic, Al. Racławickie 23, 20-049 Lublin, Poland;
| | - Sławomir Januszewski
- Laboratory of Ischemic and Neurodegenerative Brain Research, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawińskiego 5 Str., 02-106 Warsaw, Poland;
| | - Mirosław Jabłoński
- Department of Rehabilitation and Orthopedics, Medical University of Lublin, Jaczewskiego 8 Str., 20-090 Lublin, Poland;
| | - Stanisław J. Czuczwar
- Department of Pathophysiology, Medical University of Lublin, Jaczewskiego 8b Str., 20-090 Lublin, Poland;
| |
Collapse
|
4
|
Liu Y, Wu X, Du D, Liu J, Zhang W, Gao Y, Zhang H. p53 Inhibition Provides a Pivotal Protective Effect against Cerebral Ischemia-Reperfusion Injury via the Wnt Signaling Pathway. Cerebrovasc Dis 2021; 50:682-690. [PMID: 34340236 DOI: 10.1159/000516889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 04/26/2021] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION Cerebral ischemia-reperfusion injury enhances brain injury and increases its morbidity and mortality. The purpose of our study was to further explore the specific pathogenesis of cerebral ischemia disease by studying the role of p53 in cerebral ischemia-reperfusion injury and its mechanism to provide a new target for the treatment of cerebral ischemia. METHODS Middle cerebral artery occlusion (MCAo) was established in rats. The changes in p53 and apoptotic proteins in the rat model were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot. The effects of p53 inhibitors on cerebral is-chemia-reperfusion injury in rats were evaluated by modified neurological severity score (mNSS) and infarct area. Subsequently, neural stem cells (NSCs) were isolated and cultured in vitro, and oxygen and glucose deprivation (OGD) was induced to establish an in vitro ischemia-reperfusion injury model. Cell viability and migration were detected by CCK-8 and transwell assays. Apoptosis of NSCs was detected by flow cytometry. Finally, protein expression in the Wnt pathway activated by p53 was detected by Western blotting. RESULTS Compared with the sham group, p53 levels, mNSS, cerebral infarction area, and apoptosis were significantly increased in the MCAo group (p < 0.05). When the p53 inhibitor PFT-α was injected, the increase in these levels was reversed. Also, the viability and migration of cells decreased and apo-ptosis increased in the in vitro OGD model, whereas the viability, migration, and apoptosis were significantly reversed after the addition of p53 inhibitors (p < 0.05). Finally, p53 induced Wnt signaling pathway proteins β-catenin and cyclin D1 decrease in the MCAo group, while p53 inhibitors reversed their inhibitory effect on the Wnt signaling pathway. CONCLUSION We confirmed in vivo and in vitro that inhibition of p53 has a protective effect on the cerebral ischemia-reperfusion injury, which may be related to the activation of the Wnt signaling pathway.
Collapse
Affiliation(s)
- Yanwei Liu
- Department of Emergency Internal Medicine, the Affiliated Hospital of Qingdao University, Qingdao, China
| | - Xinning Wu
- Department of Cardiovascular Medicine, People's Hospital of Rizhao, Rizhao, China
| | - Deyong Du
- Department of Neurosurgery, Binzhou Medical University Hospital, Binzhou, China
| | - Jing Liu
- Bincheng Municipal Hospital, Binzhou, China
| | - Wensheng Zhang
- Department of Neurosurgery, Binzhou Medical University Hospital, Binzhou, China
| | - Yang Gao
- Department of Neurosurgery, Binzhou Medical University Hospital, Binzhou, China
| | - Haitao Zhang
- Department of Neurosurgery, Binzhou Medical University Hospital, Binzhou, China
| |
Collapse
|
5
|
Mathieu NA, Levin RH, Spratt DE. Exploring the Roles of HERC2 and the NEDD4L HECT E3 Ubiquitin Ligase Subfamily in p53 Signaling and the DNA Damage Response. Front Oncol 2021; 11:659049. [PMID: 33869064 PMCID: PMC8044464 DOI: 10.3389/fonc.2021.659049] [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: 01/26/2021] [Accepted: 03/16/2021] [Indexed: 12/27/2022] Open
Abstract
Cellular homeostasis is governed by the precise expression of genes that control the translation, localization, and termination of proteins. Oftentimes, environmental and biological factors can introduce mutations into the genetic framework of cells during their growth and division, and these genetic abnormalities can result in malignant transformations caused by protein malfunction. For example, p53 is a prominent tumor suppressor protein that is capable of undergoing more than 300 posttranslational modifications (PTMs) and is involved with controlling apoptotic signaling, transcription, and the DNA damage response (DDR). In this review, we focus on the molecular mechanisms and interactions that occur between p53, the HECT E3 ubiquitin ligases WWP1, SMURF1, HECW1 and HERC2, and other oncogenic proteins in the cell to explore how irregular HECT-p53 interactions can induce tumorigenesis.
Collapse
Affiliation(s)
- Nicholas A Mathieu
- Gustaf H. Carlson School of Chemistry and Biochemistry, Clark University, Worcester, MA, United States
| | - Rafael H Levin
- Gustaf H. Carlson School of Chemistry and Biochemistry, Clark University, Worcester, MA, United States
| | - Donald E Spratt
- Gustaf H. Carlson School of Chemistry and Biochemistry, Clark University, Worcester, MA, United States
| |
Collapse
|
6
|
Kahles T, Poon C, Qian L, Palfini V, Srinivasan SP, Swaminathan S, Blanco I, Rodney-Sandy R, Iadecola C, Zhou P, Hochrainer K. Elevated post-ischemic ubiquitination results from suppression of deubiquitinase activity and not proteasome inhibition. Cell Mol Life Sci 2021; 78:2169-2183. [PMID: 32889561 PMCID: PMC7933347 DOI: 10.1007/s00018-020-03625-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 07/28/2020] [Accepted: 08/18/2020] [Indexed: 12/24/2022]
Abstract
Cerebral ischemia-reperfusion increases intraneuronal levels of ubiquitinated proteins, but the factors driving ubiquitination and whether it results from altered proteostasis remain unclear. To address these questions, we used in vivo and in vitro models of cerebral ischemia-reperfusion, in which hippocampal slices were transiently deprived of oxygen and glucose to simulate ischemia followed by reperfusion, or the middle cerebral artery was temporarily occluded in mice. We found that post-ischemic ubiquitination results from two key steps: restoration of ATP at reperfusion, which allows initiation of protein ubiquitination, and free radical production, which, in the presence of sufficient ATP, increases ubiquitination above pre-ischemic levels. Surprisingly, free radicals did not augment ubiquitination through inhibition of the proteasome as previously believed. Although reduced proteasomal activity was detected after ischemia, this was neither caused by free radicals nor sufficient in magnitude to induce appreciable accumulation of proteasomal target proteins or ubiquitin-proteasome reporters. Instead, we found that ischemia-derived free radicals inhibit deubiquitinases, a class of proteases that cleaves ubiquitin chains from proteins, which was sufficient to elevate ubiquitination after ischemia. Our data provide evidence that free radical-dependent deubiquitinase inactivation rather than proteasomal inhibition drives ubiquitination following ischemia-reperfusion, and as such call for a reevaluation of the mechanisms of post-ischemic ubiquitination, previously attributed to altered proteostasis. Since deubiquitinase inhibition is considered an endogenous neuroprotective mechanism to shield proteins from oxidative damage, modulation of deubiquitinase activity may be of therapeutic value to maintain protein integrity after an ischemic insult.
Collapse
Affiliation(s)
- Timo Kahles
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, 10065, USA
- Department of Neurology, Cantonal Hospital Aarau, 5001, Aarau, Switzerland
| | - Carrie Poon
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Liping Qian
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Victoria Palfini
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, 10065, USA
| | | | - Shilpa Swaminathan
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Ismary Blanco
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Reunet Rodney-Sandy
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Costantino Iadecola
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Ping Zhou
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Karin Hochrainer
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, 10065, USA.
| |
Collapse
|
7
|
Di Raimondo D, Rizzo G, Musiari G, Tuttolomondo A, Pinto A. Role of Regular Physical Activity in Neuroprotection against Acute Ischemia. Int J Mol Sci 2020; 21:ijms21239086. [PMID: 33260365 PMCID: PMC7731306 DOI: 10.3390/ijms21239086] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 11/11/2020] [Accepted: 11/25/2020] [Indexed: 12/12/2022] Open
Abstract
One of the major obstacles that prevents an effective therapeutic intervention against ischemic stroke is the lack of neuroprotective agents able to reduce neuronal damage; this results in frequent evolution towards a long-term disability with limited alternatives available to aid in recovery. Nevertheless, various treatment options have shown clinical efficacy. Neurotrophins such as brain-derived neurotrophic factor (BDNF), widely produced throughout the brain, but also in distant tissues such as the muscle, have demonstrated regenerative properties with the potential to restore damaged neural tissue. Neurotrophins play a significant role in both protection and recovery of function following neurological diseases such as ischemic stroke or traumatic brain injury. Unfortunately, the efficacy of exogenous administration of these neurotrophins is limited by rapid degradation with subsequent poor half-life and a lack of blood-brain-barrier permeability. Regular exercise seems to be a therapeutic approach able to induce the activation of several pathways related to the neurotrophins release. Exercise, furthermore, reduces the infarct volume in the ischemic brain and ameliorates motor function in animal models increasing astrocyte proliferation, inducing angiogenesis and reducing neuronal apoptosis and oxidative stress. One of the most critical issues is to identify the relationship between neurotrophins and myokines, newly discovered skeletal muscle-derived factors released during and after exercise able to exert several biological functions. Various myokines (e.g., Insulin-Like Growth Factor 1, Irisin) have recently shown their ability to protects against neuronal injury in cerebral ischemia models, suggesting that these substances may influence the degree of neuronal damage in part via inhibiting inflammatory signaling pathways. The aim of this narrative review is to examine the main experimental data available to date on the neuroprotective and anti-ischemic role of regular exercise, analyzing also the possible role played by neurotrophins and myokines.
Collapse
|
8
|
Potential Molecular Target Prediction and Docking Verification of Hua-Feng-Dan in Stroke Based on Network Pharmacology. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2020; 2020:8872593. [PMID: 33193801 PMCID: PMC7641700 DOI: 10.1155/2020/8872593] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 10/12/2020] [Accepted: 10/15/2020] [Indexed: 11/18/2022]
Abstract
Objective Hua-Feng-Dan (HFD) is a Chinese medicine for stroke. This study is to predict and verify potential molecular targets and pathways of HFD against stroke using network pharmacology. Methods The TCMSP database and TCMID were used to search for the active ingredients of HFD, and GeneCards and DrugBank databases were used to search for stroke-related target genes to construct the “component-target-disease” by Cytoscape 3.7.1, which was further filtered by MCODE to build a core network. The STRING database was used to obtain interrelationships by topology and to construct a protein-protein interaction network. GO and KEGG were carried out through DAVID Bioinformatics. Autodock 4.2 was used for molecular docking. BaseSpace was used to correlate target genes with the GEO database. Results Based on OB ≥ 30% and DL ≥ 0.18, 42 active ingredients were extracted from HFD, and 107 associated targets were obtained. PPI network and Cytoscape analysis identified 22 key targets. GO analysis suggested 51 cellular biological processes, and KEGG suggested that 60 pathways were related to the antistroke mechanism of HFD, with p53, PI3K-Akt, and apoptosis signaling pathways being most important for HFD effects. Molecular docking verified interactions between the core target (CASP8, CASP9, MDM2, CYCS, RELA, and CCND1) and the active ingredients (beta-sitosterol, luteolin, baicalein, and wogonin). The identified gene targets were highly correlated with the GEO biosets, and the stroke-protection effects of Xuesaitong in the database were verified by identified targets. Conclusion HFD could regulate the symptoms of stroke through signaling pathways with core targets. This work provided a bioinformatic method to clarify the antistroke mechanism of HFD, and the identified core targets could be valuable to evaluate the antistroke effects of traditional Chinese medicines.
Collapse
|
9
|
Zhang H, Wang J, Du A, Li Y. MiR-483-3p inhibition ameliorates myocardial ischemia/reperfusion injury by targeting the MDM4/p53 pathway. Mol Immunol 2020; 125:9-14. [DOI: 10.1016/j.molimm.2020.06.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 06/07/2020] [Accepted: 06/11/2020] [Indexed: 12/11/2022]
|
10
|
PSD-93 Interacts with SynGAP and Promotes SynGAP Ubiquitination and Ischemic Brain Injury in Mice. Transl Stroke Res 2020; 11:1137-1147. [DOI: 10.1007/s12975-020-00795-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 02/05/2020] [Accepted: 02/20/2020] [Indexed: 01/14/2023]
|
11
|
Xu H, Li X, Wu X, Yang Y, Dai S, Lei T, Jing D, Luo P, Luo E. Iduna protects HT22 cells by inhibiting parthanatos: The role of the p53-MDM2 pathway. Exp Cell Res 2019; 384:111547. [PMID: 31472117 DOI: 10.1016/j.yexcr.2019.111547] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Revised: 07/30/2019] [Accepted: 08/03/2019] [Indexed: 12/12/2022]
Abstract
Traumatic brain injury (TBI) is common and often fatal in current times. The role of poly(adenosine diphosphate-ribose) polymerase (PARP)-induced cell death (parthanatos) in TBI has not been well studied. Our past study showed that oxidative stress-induced cell death includes parthanatos by confirming the occurrence of PARP activation and nuclear translocation of apoptosis-inducing factor (AIF). As oxidative stress plays a key role in pathological progression after TBI, we believe TBI may also be alleviated by the expression of Iduna, which is the only known endogenous regulator of parthanatos. Thus, a transection model in HT-22 cells was established for present study. Downregulation of Iduna aggravated the cell damage caused by mechanical cell injury, whereas upregulation of Iduna reduced mitochondrial dysfunction induced by mechanical cell injury but exerted no effect on apoptosis associated with mitochondrial dysfunction. By contrast, Iduna prevented parthanatos by reducing PARP activation and nuclear translocation of AIF. We also investigated 2 novel p53-MDM2 pathway inhibitors, AMG 232 and Nutlin-3, which substantially reduced the protective effects of Iduna. These findings indicate that Iduna might prevent TBI by specifically inhibiting parthanatos and promoting mitochondrial function, with the p53-MDM2 pathway playing a critical role.
Collapse
Affiliation(s)
- Haoxiang Xu
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Xin Li
- Department of Anesthesiology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Xiuquan Wu
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Yuefan Yang
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China; The 251th Hospital of PLA, Zhangjiakou, China
| | - Shuhui Dai
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Tao Lei
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Da Jing
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China
| | - Peng Luo
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, China.
| | - Erping Luo
- Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China.
| |
Collapse
|
12
|
Song J, Wang Y, Yuan X, Ji Q, Fan C, Zhao H, Hao W, Ren D. Stretching magnitude-dependent inactivation of AKT by ROS led to enhanced p53 mitochondrial translocation and myoblast apoptosis. Mol Biol Cell 2019; 30:1182-1197. [PMID: 30865562 PMCID: PMC6724521 DOI: 10.1091/mbc.e18-12-0770] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Previously, we had shown that high magnitude stretch (HMS), rather than low magnitude stretch (LMS), induced significant apoptosis of skeletal muscle C2C12 myoblasts. However, the molecular mechanism remains obscure. In this study, we found that p53 protein accumulated in the nucleus of LMS-loaded cells, whereas it translocated into mitochondria of HMS-loaded cells. Knocking down endogenous p53 by shRNA abrogated HMS-induced apoptosis. Furthermore, we demonstrated that overaccumulation of reactive oxygen species (ROS) during HMS-inactivated AKT that was activated in LMS-treated cells, which accounted for the distinct p53 subcellular localizations under HMS and LMS. Blocking ROS generation by N-acetylcysteine (NAC) or overexpressing constitutively active AKT vector (CA-AKT) inhibited HMS-incurred p53 mitochondrial translocation and promoted its nuclear targeting. Moreover, both NAC and CA-AKT significantly attenuated HMS-induced C2C12 apoptosis. Finally, we found that Ser389 phosphorylation of p53 was a downstream event of ROS-inactivated AKT pathway, which was critical to p53 mitochondrial trafficking during HMS stimuli. Transfecting p53-shRNA C2C12s with the mutant p53 (S389A) that was unable to target p53 to mitochondria underwent significantly lower apoptosis than transfection with wild-type p53. Altogether, our study uncovered that mitochondrial localization of p53, resulting from p53 Ser389 phosphorylation through ROS-inactivated AKT pathway, prompted C2C12 myoblast apoptosis during HMS stimulation.
Collapse
Affiliation(s)
- Jing Song
- Department of Stomatology Medical Center, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.,Central Laboratory of Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.,Department of Orthodontics, School of Stomatology, Qingdao University, Qingdao, China
| | - Yaqi Wang
- Department of Stomatology Medical Center, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.,Central Laboratory of Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.,Department of Orthodontics, School of Stomatology, Qingdao University, Qingdao, China
| | - Xiao Yuan
- Department of Stomatology Medical Center, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.,Department of Orthodontics, School of Stomatology, Qingdao University, Qingdao, China
| | - Qiuxia Ji
- Department of Stomatology Medical Center, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.,Central Laboratory of Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China
| | - Cunhui Fan
- Department of Stomatology Medical Center, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.,Central Laboratory of Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China
| | - Hongmei Zhao
- Department of Stomatology Medical Center, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.,Central Laboratory of Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China
| | - Wenjing Hao
- Department of Stomatology Medical Center, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.,Central Laboratory of Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China
| | - Dapeng Ren
- Department of Stomatology Medical Center, Affiliated Hospital of Qingdao University, Qingdao University, Qingdao, China.,Department of Orthodontics, School of Stomatology, Qingdao University, Qingdao, China
| |
Collapse
|
13
|
Lee BB, Kim Y, Kim D, Cho EY, Han J, Kim HK, Shim YM, Kim DH. Metformin and tenovin-6 synergistically induces apoptosis through LKB1-independent SIRT1 down-regulation in non-small cell lung cancer cells. J Cell Mol Med 2019; 23:2872-2889. [PMID: 30710424 PMCID: PMC6433689 DOI: 10.1111/jcmm.14194] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 11/26/2018] [Accepted: 01/02/2019] [Indexed: 12/20/2022] Open
Abstract
Sirtuin 1 (SIRT1) is known to play a role in a variety of tumorigenesis processes by deacetylating histone and non‐histone proteins; however, antitumour effects by suppressing SIRT1 activity in non‐small cell lung cancer (NSCLC) remain unclear. This study was designed to scrutinize clinicopathological significance of SIRT1 in NSCLC and investigate effects of metformin on SIRT1 inhibition. This study also evaluated new possibilities of drug combination using a SIRT1 inhibitor, tenovin‐6, in NSCLC cell lines. It was found that SIRT1 was overexpressed in 300 (62%) of 485 formalin‐fixed paraffin‐embedded NSCLC tissues. Its overexpression was significantly associated with reduced overall survival and poor recurrence‐free survival after adjusted for histology and pathologic stage. Thus, suppression of SIRT1 expression may be a reasonable therapeutic strategy for NSCLC. Metformin in combination with tenovin‐6 was found to be more effective in inhibiting cell growth than either agent alone in NSCLC cell lines with different liver kinase B1 (LKB1) status. In addition, metformin and tenovin‐6 synergistically suppressed SIRT1 expression in NSCLC cells regardless of LKB1 status. The marked reduction in SIRT1 expression by combination of metformin and tenovin‐6 increased acetylation of p53 at lysine 382 and enhanced p53 stability in LKB1‐deficient A549 cells. The combination suppressed SIRT1 promoter activity more effectively than either agent alone by up‐regulating hypermethylation in cancer 1 (HIC1) binding at SIRT1 promoter. Also, suppressed SIRT1 expression by the combination synergistically induced caspase‐3‐dependent apoptosis. The study concluded that metformin with tenovin‐6 may enhance antitumour effects through LKB1‐independent SIRT1 down‐regulation in NSCLC cells.
Collapse
Affiliation(s)
- Bo Bin Lee
- Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon, Korea
| | - Yujin Kim
- Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon, Korea
| | - Dongho Kim
- Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon, Korea
| | - Eun Yoon Cho
- Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Joungho Han
- Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Hong Kwan Kim
- Department of Thoracic and Cardiovascular Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Young Mog Shim
- Department of Thoracic and Cardiovascular Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Duk-Hwan Kim
- Department of Molecular Cell Biology, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon, Korea
| |
Collapse
|
14
|
Zhao Z, Guan JZ, Wu M, Lai GH, Zhu ZL. Downregulation of microRNA-23b protects against ischemia-reperfusion injury via p53 signaling pathway by upregulating MDM4 in rats. J Cell Biochem 2018; 120:4599-4612. [PMID: 30537038 DOI: 10.1002/jcb.27748] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 08/31/2018] [Indexed: 11/08/2022]
Abstract
Total knee arthroplasty is a commonly performed safe procedure and typically executed in severe knee arthritis, but it also triggers ischemia-reperfusion injury (IRI). More recently, microRNAs (miRs) have been reported to play a contributory role in IRI through the key signaling pathway. Hence, the current study aimed to investigate the effect and specific mechanism of microRNA-23b (miR-23b), murine double minute 4 (MDM4), and the p53 signaling pathway in IRI rat models. First, the IRI model was established, and the expression pattern of miR-23b, MDM4, and the p53 signaling pathway-related genes was characterized in cartilaginous tissues. Then, miR-23b mimics or inhibitors were applied for the elevation or the depletion of the miR-23b expression and siRNA-MDM4 for the depletion of the MDM4 expression in the articular chondrocytes. By means of immunohistochemistry, quantitative real-time polymerase chain reaction, and Western blot analysis, IRI rats exhibited increased miR-23b expression, activated p53 signaling pathway, and decreased MDM4 expression. MDM4 was verified as a target gene of miR-23b through. Downregulated miR-23b increased the expression of MDM4, AKT, and Bcl-2, but decreased the expression of p53, p21, and Bax. In addition, a series of cell experiments demonstrated that downregulated miR-23b promoted articular chondrocyte proliferation and cell cycle entry, but inhibited articular chondrocyte apoptosis. The absence of the effects of miR-23b was observed after MDM4 knocked down. Our results indicate that silencing miR-23b could act to attenuate IRI and reduce the apoptosis of articular chondrocytes through inactivation of the p53 signaling pathway by upregulating MDM4, which provide basic therapeutic considerations for a novel target against IRI.
Collapse
Affiliation(s)
- Zhi Zhao
- Department of Orthopedics, The First Affiliated Hospital of Bengbu Medical College, Anhui Key Laboratory of Tissue Transplantation, Bengbu, China
| | - Jian-Zhong Guan
- Department of Orthopedics, The First Affiliated Hospital of Bengbu Medical College, Anhui Key Laboratory of Tissue Transplantation, Bengbu, China
| | - Min Wu
- Department of Orthopedics, The First Affiliated Hospital of Bengbu Medical College, Anhui Key Laboratory of Tissue Transplantation, Bengbu, China
| | - Gui-Hua Lai
- Department of Anatomy, Bengbu Medical College, Bengbu, China
| | - Zhong-Lian Zhu
- Department of Orthopedics, The First Affiliated Hospital of Bengbu Medical College, Anhui Key Laboratory of Tissue Transplantation, Bengbu, China
| |
Collapse
|
15
|
Free Radical Damage in Ischemia-Reperfusion Injury: An Obstacle in Acute Ischemic Stroke after Revascularization Therapy. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:3804979. [PMID: 29770166 PMCID: PMC5892600 DOI: 10.1155/2018/3804979] [Citation(s) in RCA: 278] [Impact Index Per Article: 46.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 12/07/2017] [Indexed: 12/16/2022]
Abstract
Acute ischemic stroke is a common cause of morbidity and mortality worldwide. Thrombolysis with recombinant tissue plasminogen activator and endovascular thrombectomy are the main revascularization therapies for acute ischemic stroke. However, ischemia-reperfusion injury after revascularization therapy can result in worsening outcomes. Among all possible pathological mechanisms of ischemia-reperfusion injury, free radical damage (mainly oxidative/nitrosative stress injury) has been found to play a key role in the process. Free radicals lead to protein dysfunction, DNA damage, and lipid peroxidation, resulting in cell death. Additionally, free radical damage has a strong connection with inducing hemorrhagic transformation and cerebral edema, which are the major complications of revascularization therapy, and mainly influencing neurological outcomes due to the disruption of the blood-brain barrier. In order to get a better clinical prognosis, more and more studies focus on the pharmaceutical and nonpharmaceutical neuroprotective therapies against free radical damage. This review discusses the pathological mechanisms of free radicals in ischemia-reperfusion injury and adjunctive neuroprotective therapies combined with revascularization therapy against free radical damage.
Collapse
|
16
|
Cao L, Zhang Y, Zhang S, Jiang TP, Chen L, Liu J, Zhou S. MicroRNA-29b alleviates oxygen and glucose deprivation/reperfusion-induced injury via inhibition of the p53-dependent apoptosis pathway in N2a neuroblastoma cells. Exp Ther Med 2017; 15:67-74. [PMID: 29399057 PMCID: PMC5766061 DOI: 10.3892/etm.2017.5410] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 07/20/2017] [Indexed: 12/14/2022] Open
Abstract
Cerebral ischemic injury causes severe brain damage and remains one of the leading causes of morbidity and mortality worldwide. Members of the microRNA-29 (miR-29) family are involved in regulating the process of ischemia and may be developed as biomarkers to diagnose and treat cerebral ischemia. The role of miR-29b in cerebral ischemia injury remains poorly understood. The purpose of the present study was to investigate whether miR-29b overexpression suppressed cerebral ischemic injury and to explore its underlying mechanism of action. The results demonstrated that levels of miR-29b in N2a neuroblastoma cells decreased following oxygen and glucose deprivation/reperfusion (OGD/R) treatment. Transfection with miR-29b mimics significantly increased cell viability, decreased lactate dehydrogenase (LDH) leakage, inhibited apoptosis by decreasing morphological changes occurring in the nuclei and reduced caspase-3 activity in OGD/R-treated N2a cells. Conversely, miR-29b inhibitors enhanced OGD/R-induced cytotoxicity and apoptosis. In addition, the miR-29b mimics blocked the increase in Bax and p53 expression and decreased Bcl-2 expression in OGD/R-treated N2a cells, whereas miR-29b inhibitors exacerbated the changes in the expression of these apoptosis-associated proteins caused by OGD/R. p53 knockdown using p53 small interfering RNA decreased cell viability and increased LDH leakage, reversing the improvements that the miR-29b mimics induced in damaged cells. Taken together, the results of the present study demonstrated that miR-29b attenuates ischemic injury by negatively regulating the p53-dependent apoptosis pathway and may therefore be a novel potential therapeutic target for treating ischemic stroke.
Collapse
Affiliation(s)
- Lei Cao
- Department of Interventional Radiology, Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Yu Zhang
- Department of Interventional Radiology, Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Shuai Zhang
- Department of Interventional Radiology, Tumor Hospital Affiliated with Guizhou Medical University, Guiyang, Guizhou 550000, P.R. China
| | - Tian-Peng Jiang
- Department of Interventional Radiology, The Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Li Chen
- Department of Interventional Radiology, Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Jing Liu
- Department of Interventional Radiology, Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
| | - Shi Zhou
- Department of Interventional Radiology, The Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou 550004, P.R. China
| |
Collapse
|
17
|
Hochrainer K. Protein Modifications with Ubiquitin as Response to Cerebral Ischemia-Reperfusion Injury. Transl Stroke Res 2017; 9:157-173. [DOI: 10.1007/s12975-017-0567-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 08/11/2017] [Accepted: 08/17/2017] [Indexed: 12/12/2022]
|
18
|
Yamada Y, Kinoshita I, Kohashi K, Yamamoto H, Kuma Y, Ito T, Koda K, Kisanuki A, Kurosawa M, Yoshimura M, Furue M, Oda Y. HIF-1α, MDM2, CDK4, and p16 expression in ischemic fasciitis, focusing on its ischemic condition. Virchows Arch 2017; 471:117-122. [PMID: 28477272 DOI: 10.1007/s00428-017-2122-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 03/02/2017] [Accepted: 04/04/2017] [Indexed: 11/28/2022]
Abstract
Ischemic fasciitis is a benign myofibroblastic lesion, occurring in the sacral region or proximal thigh of elderly or bedridden individuals. The pathogenesis of ischemic fasciitis is thought to be based on ischemic condition; however, it has never been demonstrated. In this study, we examined the expression of ischemia-associated proteins in ischemic fasciitis by immunohistochemical and genetic methods. Specifically, this study aimed to reveal the expression of HIF-1α, MDM2, CDK4, p16, and gene amplification of MDM2 gene. Seven cases of ischemic fasciitis from among the soft-tissue tumors registered at our institution were retrieved. Histopathological findings were as follows: poorly demarcated nodular masses, a proliferation of spindle-shaped fibroblastic or myofibroblastic cells with oval nuclei and eosinophilic or pale cytoplasm, zonal fibrinous deposition, pseudocystic degeneration, granulation-like proliferation of capillary vessels, ganglion-like cells, myxoid or hyalinized stroma, and chronic inflammatory infiltration. Immunohistochemically, the spindle cells were positive for HIF-1α (7/7 cases), MDM2 (4/7 cases), CDK4 (4/7 cases), p16 (7/7 cases), p53 (2/7 case), cyclin D1 (7/7 cases), and alpha-smooth muscle actin (6/7 cases). Neither MDM2 gene amplification nor USP6 gene split signal was detected in any case. Overexpression of the above proteins may be associated with the pathogenic mechanism of ischemic fasciitis. It is noted that the immunohistochemical positivity of MDM2, CDK4, and p16 do not necessarily indicate malignant neoplasm such as dedifferentiated liposarcoma.
Collapse
Affiliation(s)
- Yuichi Yamada
- Department of Anatomic Pathology, Pathological Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka-shi, Fukuoka-ken, 812-8582, Japan
| | - Izumi Kinoshita
- Department of Anatomic Pathology, Pathological Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka-shi, Fukuoka-ken, 812-8582, Japan
| | - Kenichi Kohashi
- Department of Anatomic Pathology, Pathological Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka-shi, Fukuoka-ken, 812-8582, Japan
| | - Hidetaka Yamamoto
- Department of Anatomic Pathology, Pathological Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka-shi, Fukuoka-ken, 812-8582, Japan
| | - Yuki Kuma
- Department of Anatomic Pathology, Pathological Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka-shi, Fukuoka-ken, 812-8582, Japan
| | - Takamichi Ito
- Department of Anatomic Pathology, Pathological Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka-shi, Fukuoka-ken, 812-8582, Japan
| | - Kenji Koda
- Department of Pathology, Fujieda Municipal General Hospital, 4-1-11 Surugadai, Fujieda-shi, Shizuoka-ken, 426-8677, Japan
| | - Atsushi Kisanuki
- Department of Pathology, Nichinan Prefectural Miyazaki Hospital, 1-9-5 Kiyama, Nichinan-shi, Miyazaki-ken, 887-0013, Japan
| | - Manabu Kurosawa
- Department of Pathology, Nagahama City Hospital, 313 Ooinui-cho, Nagahama-shi, Shiga-ken, 526-8580, Japan
| | - Michiko Yoshimura
- Department of Pathology, Belland Hospital, 500-3 Higashiyama, Naka-ku, Sakai-shi, Osaka, 599-8247, Japan
| | - Masutaka Furue
- Department of Dermatology, Graduate School of Medical Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka-shi, Fukuoka-ken, 812-8582, Japan
| | - Yoshinao Oda
- Department of Anatomic Pathology, Pathological Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka-shi, Fukuoka-ken, 812-8582, Japan.
| |
Collapse
|
19
|
Is Cytoplasmic PTEN a Specific Target for Neuronal Survival? Mol Neurobiol 2014; 52:1758-1764. [DOI: 10.1007/s12035-014-8922-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 09/30/2014] [Indexed: 01/16/2023]
|
20
|
Wan C, Chen J, Hu B, Zou H, Li A, Guo A, Jiang J. Downregulation of UBE2Q1 is associated with neuronal apoptosis in rat brain cortex following traumatic brain injury. J Neurosci Res 2013; 92:1-12. [PMID: 24166684 DOI: 10.1002/jnr.23305] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2013] [Revised: 07/05/2013] [Accepted: 09/03/2013] [Indexed: 11/06/2022]
Abstract
Aberrant functionality of the ubiquitin proteasome system (UPS) has been implicated in the pathology of various neurological disorders. Although it has been reported that the expressions of various UPS components were altered significantly following traumatic brain injury (TBI), detailed information on the subject remains largely unclear. In the study, using microarray assay, we identified a gene encoding ubiquitin-conjugating enzyme E2Q1 (UBE2Q1) that was significantly downregulated during TBI. Western blot and immunohistochemical analyses verified the reduced expression of UBE2Q1 in ipsilateral brain cortex adjacent to the lesion site compared with the contralateral and sham-operated ones. Double-immunofluorescence staining indicated that UBE2Q1 was expressed mainly in the nucleus of neurons, with a minority in astrocytes in normal cortex. In addition, we observed a remarkable reduction in the number of UBE2Q1-positive neurons following brain trauma. Furthermore, we showed that TBI resulted in a significant increase in the levels of p53, bax, p21 and active caspase 3 in brain cortex, which was correlated with decreased expression of UBE2Q1. We also found that knockdown of UBE2Q1 apparently increased the level of p53, whereas overexpressing UBE2Q1 attenuated cellular p53 level in PC12 neuronal cells. Accordingly, interference with UBE2Q1 augmented H2O2-induced apoptosis of PC12 cells. Taken together, our findings indicate that UBE2Q1 might play an important role in the neuropathological process of TBI through modulating p53 signaling.
Collapse
Affiliation(s)
- Chunhua Wan
- School of Public Health, Nantong University, Nantong, People's Republic of China
| | | | | | | | | | | | | |
Collapse
|
21
|
Almeida A. Genetic determinants of neuronal vulnerability to apoptosis. Cell Mol Life Sci 2013; 70:71-88. [PMID: 22695677 PMCID: PMC11113535 DOI: 10.1007/s00018-012-1029-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 04/22/2012] [Accepted: 05/07/2012] [Indexed: 12/18/2022]
Abstract
Apoptosis is a common mode of cell death that contributes to neuronal loss associated with neurodegeneration. Single-nucleotide polymorphisms (SNPs) in chromosomal DNA are contributing factors dictating natural susceptibility of humans to disease. Here, the most common SNPs affecting neuronal vulnerability to apoptosis are reviewed in the context of neurological disorders. Polymorphic variants in genes encoding apoptotic proteins, either from the extrinsic (FAS, TNF-α, CASP8) or the intrinsic (BAX, BCL2, CASP3, CASP9) pathways could be highly valuable in the diagnosis of neurodegenerative diseases and stroke. Interestingly, the Arg72Pro SNP in TP53, the gene encoding tumor suppressor p53, was recently revealed a biomarker of poor prognosis in stroke due to its ability to modulate neuronal apoptotic death. Search for new SNPs responsible for genetic variability to apoptosis will ensure the implementation of novel diagnostic and prognostic tools, as well as therapeutic strategies against neurological diseases.
Collapse
Affiliation(s)
- Angeles Almeida
- Instituto de Investigación Biomédica de Salamanca, Hospital Universitario de Salamanca, 37007, Salamanca, Spain.
| |
Collapse
|
22
|
Abstract
Oxidative stress has emerged as a key deleterious factor in brain ischemia and reperfusion. Malfunction of the oxidative respiratory chain in mitochondria combines with the activation of cytoplasmic oxidases to generate a burst of reactive oxygen species that cannot be neutralised by the cell's antioxidant mechanisms. As a result, oxidative stress contributes directly to necrosis and apoptosis through a number of pathways in ischemic tissue. Pharmacological intervention with antioxidants or enhancers of endogenous antioxidant molecules is proving to be difficult due to the speed and scope of the oxidative impact. Additionally, the knowledge that neuronal fate in ischemic stroke is tightly linked to other brain cells like endothelial cells and astrocytes has shifted the focus of study from isolated neurons to the neurovascular unit. For this reason, recent efforts have been directed towards understanding the sources of oxidative stress in ischemic stroke and attempting to block the generation of oxygen radicals.
Collapse
|
23
|
Singh S, Raina V, Chavali PL, Dubash T, Kadreppa S, Parab P, Chattopadhyay S. Regulation of GAD65 expression by SMAR1 and p53 upon Streptozotocin treatment. BMC Mol Biol 2012; 13:28. [PMID: 22978699 PMCID: PMC3459802 DOI: 10.1186/1471-2199-13-28] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Accepted: 09/07/2012] [Indexed: 12/03/2022] Open
Abstract
Background GAD65 (Glutamic acid decarboxylase 65 KDa isoform) is one of the most important auto-antigens involved in Type 1 diabetes induction. Although it serves as one of the first injury markers of β-islets, the mechanisms governing GAD65 expression remain poorly understood. Since the regulation of GAD65 is crucial for the proper functioning of insulin secreting cells, we investigated the stress induced regulation of GAD65 transcription. Results The present study shows that SMAR1 regulates GAD65 expression at the transcription level. Using a novel protein-DNA pull-down assay, we show that SMAR1 binding is very specific to GAD65 promoter but not to the other isoform, GAD67. We show that Streptozotocin (STZ) mediated DNA damage leads to upregulation of SMAR1 and p53 expression, resulting in elevated levels of GAD65, in both cell lines as well as mouse β-islets. SMAR1 and p53 act synergistically to up-regulate GAD65 expression upon STZ treatment. Conclusion We propose a novel mechanism of GAD65 regulation by synergistic activities of SMAR1 and p53.
Collapse
Affiliation(s)
- Sandeep Singh
- Centre for Human Genetics, School of Health Sciences, Central University of Punjab, Bathinda 151001, India.
| | | | | | | | | | | | | |
Collapse
|
24
|
Hochrainer K, Jackman K, Anrather J, Iadecola C. Reperfusion rather than ischemia drives the formation of ubiquitin aggregates after middle cerebral artery occlusion. Stroke 2012; 43:2229-35. [PMID: 22700531 DOI: 10.1161/strokeaha.112.650416] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND AND PURPOSE Cerebral ischemia leads to accumulation of ubiquitinated protein aggregates. However, the factors triggering ubiquitination and their impact on the outcome of cerebral ischemia remain poorly understood. Here we investigate the relationship between ubiquitin aggregation and duration of ischemia/reperfusion, infarct volume, and proteasomal activity in a mouse model of focal ischemia. METHODS Free ubiquitin and ubiquitin aggregate levels were examined by Western blotting in the mouse neocortex and striatum after different periods of ischemia/reperfusion and permanent ischemia induced by middle cerebral artery occlusion. Infarct volumes were measured in thionin-stained brain sections. Proteasome activity was studied by fluorometric peptidase activity assay. RESULTS Following transient ischemia, ubiquitin aggregates were detected in the ipsilateral neocortex and, to a lesser extent, striatum only after induction of reperfusion. In permanent ischemia, no ubiquitin aggregates were found. Shorter ischemic periods producing no or minimal tissue damage (10-15 minutes) resulted in ubiquitin aggregate levels similar to those produced by ischemia resulting in substantial infarction (30 minutes). Proteasomal impairment was greatest in ischemia without reperfusion, in which no ubiquitin aggregates were detected. CONCLUSIONS The data demonstrate that reperfusion rather than ischemia leads to the appearance of ubiquitinated aggregates, which form in the absence of major tissue damage and are not correlated with decreased proteasomal peptidase activity. Ubiquitin aggregates may form in potentially viable brain tissue, which may be later recruited into infarction by factors independent of ubiquitination.
Collapse
Affiliation(s)
- Karin Hochrainer
- Division of Neurobiology, Department of Neurology and Neuroscience, Weill Cornell Medical College, New York, NY 10065, USA
| | | | | | | |
Collapse
|
25
|
Scruggs SB, Zong NC, Wang D, Stefani E, Ping P. Post-translational modification of cardiac proteasomes: functional delineation enabled by proteomics. Am J Physiol Heart Circ Physiol 2012; 303:H9-18. [PMID: 22523251 DOI: 10.1152/ajpheart.00189.2012] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Proteasomes are ubiquitously expressed multicatalytic complexes that serve as key regulators of protein homeostasis. There are several lines of evidence indicating that proteasomes exist in heterogeneous subpopulations in cardiac muscle, differentiated, in part, by post-translational modifications (PTMs). PTMs regulate numerous facets of proteasome function, including catalytic activities, complex assembly, interactions with associating partners, subcellular localization, substrate preference, and complex turnover. Classical technologies used to identify PTMs on proteasomes have lacked the ability to determine site specificity, quantify stoichiometry, and perform large-scale, multi-PTM analysis. Recent advancements in proteomic technologies have largely overcome these limitations. We present here a discussion on the importance of PTMs in modulating proteasome function in cardiac physiology and pathophysiology, followed by the presentation of a state-of-the-art proteomic workflow for identifying and quantifying PTMs of cardiac proteasomes.
Collapse
Affiliation(s)
- Sarah B Scruggs
- Division of Cardiology, Department of Physiology, University of California, Los Angeles, USA
| | | | | | | | | |
Collapse
|
26
|
Yerlikaya A, Okur E, Ulukaya E. The p53-independent induction of apoptosis in breast cancer cells in response to proteasome inhibitor bortezomib. Tumour Biol 2012; 33:1385-92. [PMID: 22477712 DOI: 10.1007/s13277-012-0386-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Accepted: 03/21/2012] [Indexed: 10/28/2022] Open
Abstract
An important hallmark of cancer cells is acquired resistance toward apoptosis. The apoptotic pathway is the most well-defined cell death program and is characterized by several morphological and biochemical features. The tumor suppressor protein p53 is a critical regulator of apoptosis in many cell types. p53 stimulates a wide network of signals that act through either extrinsic or intrinsic pathways of apoptosis. However, a number of studies have shown that apoptosis can be induced in a p53-independent manner as well. In this study, we examined the mechanism of apoptosis in p53-null breast cancer cells in response to the proteasome inhibitor bortezomib. Initially, we determined the p53 status of 4T1 breast carcinoma and 4THMpc (a highly mestatic derivative of 4T1) cells and verified that both cells are p53 deficient. It was subsequently shown that apoptosis can be induced in both cells in a dose-dependent manner in response to bortezomib treatment, based on DNA fragmentation evidence. Western blot analyses of ubiquitin-protein conjugates additionally showed that the proteasome is potently inhibited by bortezomib in p53-null 4T1 and 4THMpc cells. The results presented in the current study also show that caspase-3 is significantly activated in response to the treatment with bortezomib, implying that induction of apoptosis in these p53-deficient cells is occurring via caspase-3. The additional results presented here suggest that the pro-apoptotic proteins Bad, Noxa, and Puma are not critical regulators of apoptosis induction in p53-null 4T1 and 4THMpc cells. Similarly, there was no difference in the expression level of Mcl-1 in treated cells, suggesting that this anti-apoptotic protein is also uninvolved in the apoptotic response resulting from bortezomib treatment. In contrast, a very significant upregulation of the anti-apoptotic protein Hsp25/27 was detected in these p53-deficient cells after treatment with bortezomib. If the increased expression of Hsp25/27 protein levels are muting the apoptotic effects of the bortezomib treatment, then the apoptosis-inducing effects of such proteasome inhibitors might be increased with approaches simultaneously inhibiting Hsp25/27 protein in p53-deficient cells.
Collapse
Affiliation(s)
- Azmi Yerlikaya
- Art and Science Faculty, Department of Biology, Dumlupınar University, Kütahya, Turkey.
| | | | | |
Collapse
|
27
|
Raz L, Zhang QG, Han D, Dong Y, De Sevilla L, Brann DW. Acetylation of the pro-apoptotic factor, p53 in the hippocampus following cerebral ischemia and modulation by estrogen. PLoS One 2011; 6:e27039. [PMID: 22046440 PMCID: PMC3202599 DOI: 10.1371/journal.pone.0027039] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Accepted: 10/09/2011] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Recent studies demonstrate that acetylation of the transcription factor, p53 on lysine(373) leads to its enhanced stabilization/activity and increased susceptibility of cells to stress. However, it is not known whether acetylation of p53 is altered in the hippocampus following global cerebral ischemia (GCI) or is regulated by the hormone, 17β-estradiol (17β-E(2)), and thus, this study examined these issues. METHODOLOGY/PRINCIPAL FINDINGS The study revealed that Acetyl p53-Lysine(373) levels were markedly increased in the hippocampal CA1 region after GCI at 3 h, 6 h and 24 h after reperfusion, an effect strongly attenuated by 17β-E(2). 17β-E(2) also enhanced interaction of p53 with the ubiquitin ligase, Mdm2, increased ubiquitination of p53, and induced its down-regulation, as well as attenuated elevation of the p53 transcriptional target, Puma. We also observed enhanced acetylation of p53 at a different lysine (Lys(382)) at 3 h after reperfusion, and 17β-E(2) also markedly attenuated this effect. Furthermore, administration of an inhibitor of CBP/p300 acetyltransferase, which acetylates p53, was strongly neuroprotective of the CA1 region following GCI. In long-term estrogen deprived (LTED) animals, the ability of 17β-E(2) to attenuate p53 acetylation was lost, and intriguingly, Acetyl p53-Lysine(373) levels were markedly elevated in sham (non-ischemic) LTED animals. Finally, intracerebroventricular injections of Gp91ds-Tat, a specific NADPH oxidase (NOX2) inhibitor, but not the scrambled tat peptide control (Sc-Tat), attenuated acetylation of p53 and reduced levels of Puma following GCI. CONCLUSIONS/SIGNIFICANCE The studies demonstrate that p53 undergoes enhanced acetylation in the hippocampal CA1 region following global cerebral ischemia, and that the neuroprotective agent, 17β-E(2), markedly attenuates the ischemia-induced p53 acetylation. Furthermore, following LTED, the suppressive effect of 17β-E(2) on p53 acetylation is lost, and p53 acetylation increases in the hippocampus, which may explain previous reports of increased sensitivity of the hippocampus to ischemic stress following LTED.
Collapse
Affiliation(s)
- Limor Raz
- Institute of Molecular Medicine and Genetics, Georgia Health Sciences University, Augusta, Georgia, United States of America
| | - Quan-guang Zhang
- Institute of Molecular Medicine and Genetics, Georgia Health Sciences University, Augusta, Georgia, United States of America
| | - Dong Han
- Institute of Molecular Medicine and Genetics, Georgia Health Sciences University, Augusta, Georgia, United States of America
| | - Yan Dong
- Institute of Molecular Medicine and Genetics, Georgia Health Sciences University, Augusta, Georgia, United States of America
| | - Liesl De Sevilla
- Institute of Molecular Medicine and Genetics, Georgia Health Sciences University, Augusta, Georgia, United States of America
| | - Darrell W. Brann
- Institute of Molecular Medicine and Genetics, Georgia Health Sciences University, Augusta, Georgia, United States of America
- * E-mail:
| |
Collapse
|
28
|
Alterations of ubiquitylation and sumoylation in conventional renal cell carcinomas after the Chernobyl accident: a comparison with Spanish cases. Virchows Arch 2011; 459:307-13. [PMID: 21786080 DOI: 10.1007/s00428-011-1124-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Revised: 06/07/2011] [Accepted: 07/04/2011] [Indexed: 01/17/2023]
Abstract
We determined whether ubiquitylation and sumoylation processes are involved in conventional renal cell carcinogenesis associated with chronic, long-term, persistent low doses of ionizing radiation (IR) in patients living for more than 20 years in cesium-137 ((137)Cs)-contaminated areas after the Chernobyl accident in Ukraine. To this end, we assessed the immunohistochemical expression of ubiquitin (Ub), SUMO1, SUMO E2 conjugating enzyme Ubc9, and the cell cycle regulators p53, mdm2, and p14(ARF) in 38 conventional renal cell carcinomas from Ukrainian patients with different degrees of radiation exposure after the Chernobyl accident. As control cases, 18 conventional renal carcinoma (cRCC) tissues from a Spanish cohort were analyzed. No significant differences between the Ukrainian and Spanish groups were found regarding Ub overexpression, although being higher in the Ukrainian cases. Furthermore, this expression was inversely associated with SUMO1 and Ubc9, with no correlation with tumor nuclear grade. There was also a direct relationship between Ubc9 and inflammatory response. These findings do not allow us to consider the immunohistochemical expression of ubiquitylation and sumoylation as valuable markers for discriminating the effects of long-term, low-dose IR exposure in cRCC carcinogenesis.
Collapse
|
29
|
Chen H, Yoshioka H, Kim GS, Jung JE, Okami N, Sakata H, Maier CM, Narasimhan P, Goeders CE, Chan PH. Oxidative stress in ischemic brain damage: mechanisms of cell death and potential molecular targets for neuroprotection. Antioxid Redox Signal 2011; 14:1505-17. [PMID: 20812869 PMCID: PMC3061196 DOI: 10.1089/ars.2010.3576] [Citation(s) in RCA: 550] [Impact Index Per Article: 42.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Significant amounts of oxygen free radicals (oxidants) are generated during cerebral ischemia/reperfusion, and oxidative stress plays an important role in brain damage after stroke. In addition to oxidizing macromolecules, leading to cell injury, oxidants are also involved in cell death/survival signal pathways and cause mitochondrial dysfunction. Experimental data from laboratory animals that either overexpress (transgenic) or are deficient in (knock-out) antioxidant proteins, mainly superoxide dismutase, have provided strong evidence of the role of oxidative stress in ischemic brain damage. In addition to mitochondria, recent reports demonstrate that NADPH oxidase (NOX), an important pro-oxidant enzyme, is also involved in the generation of oxidants in the brain after stroke. Inhibition of NOX is neuroprotective against cerebral ischemia. We propose that superoxide dismutase and NOX activity in the brain is a major determinant for ischemic damage/repair and that these major anti- and pro-oxidant enzymes are potential endogenous molecular targets for stroke therapy.
Collapse
Affiliation(s)
- Hai Chen
- Departments of Neurosurgery and Neurology and Neurological Sciences and Program in Neurosciences, Stanford University School of Medicine, 1201 Welch Road, Stanford, CA 94305-5487, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Abstract
p53 is a key modulator of cellular stress responses. It is activated in the ischemic areas of brain, and contributes to neuronal apoptosis. In various stroke models, p53 deficiency or applications of p53 inhibitors can significantly attenuate brain damage. p53-mediated neuronal apoptosis occurs through various molecular mechanisms. The transcriptional pathway is an important mechanism through which p53 induces neuronal apoptosis by up-regulating the expression of its target gene p21(WAF), Peg3/Pw1 or p53-up-regulated modulator of apoptosis (PUMA). In addition, p53 disrupts NF-kappaB binding to p300 and blocks NF-kappaB-mediated survival signaling. On the other hand, the transcription-independent pathway mechanism is also of great importance. In this pathway, p53 is translocated to mitochondrial and mediates the release of cytochrome c. In both pathways, p53 seems to play a key role in post-ischemic brain damage and has become a therapeutic target against stroke pathology.
Collapse
|
31
|
CK2 is a novel negative regulator of NADPH oxidase and a neuroprotectant in mice after cerebral ischemia. J Neurosci 2010; 29:14779-89. [PMID: 19940173 DOI: 10.1523/jneurosci.4161-09.2009] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
NADPH oxidase is a major complex that produces reactive oxygen species (ROSs) during the ischemic period and aggravates brain damage and cell death after ischemic injury. Although many approaches have been tested for preventing production of ROSs by NADPH oxidase in ischemic brain injury, the regulatory mechanisms of NADPH oxidase activity after cerebral ischemia are still unclear. In this study, we identified casein kinase 2 (CK2) as a critical modulator of NADPH oxidase and elucidated the role of CK2 as a neuroprotectant after oxidative insults to the brain. We found that the protein levels of the catalytic subunits CK2alpha and CK2alpha', as well as the total activity of CK2, are significantly reduced after transient focal cerebral ischemia (tFCI). We also found this deactivation of CK2 caused by ischemia/reperfusion increases expression of Nox2 and translocation of p67(phox) and Rac1 to the membrane after tFCI. Interestingly, we found that the inactive status of Rac1 was captured by the catalytic subunit CK2alpha under normal conditions. However, binding between CK2alpha and Rac1 was immediately diminished after tFCI, and Rac1 activity was markedly increased after CK2 inhibition. Moreover, we found that deactivation of CK2 in the mouse brain enhances production of ROSs and neuronal cell death via increased NADPH oxidase activity. The increased brain infarct volume caused by CK2 inhibition was restored by apocynin, a NADPH oxidase inhibitor. This study suggests that CK2 can be a direct molecular target for modulation of NADPH oxidase activity after ischemic brain injury.
Collapse
|
32
|
Niizuma K, Yoshioka H, Chen H, Kim GS, Jung JE, Katsu M, Okami N, Chan PH. Mitochondrial and apoptotic neuronal death signaling pathways in cerebral ischemia. Biochim Biophys Acta Mol Basis Dis 2009; 1802:92-9. [PMID: 19751828 DOI: 10.1016/j.bbadis.2009.09.002] [Citation(s) in RCA: 259] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2009] [Revised: 08/26/2009] [Accepted: 09/08/2009] [Indexed: 10/20/2022]
Abstract
Mitochondria play important roles as the powerhouse of the cell. After cerebral ischemia, mitochondria overproduce reactive oxygen species (ROS), which have been thoroughly studied with the use of superoxide dismutase transgenic or knockout animals. ROS directly damage lipids, proteins, and nucleic acids in the cell. Moreover, ROS activate various molecular signaling pathways. Apoptosis-related signals return to mitochondria, then mitochondria induce cell death through the release of pro-apoptotic proteins such as cytochrome c or apoptosis-inducing factor. Although the mechanisms of cell death after cerebral ischemia remain unclear, mitochondria obviously play a role by activating signaling pathways through ROS production and by regulating mitochondria-dependent apoptosis pathways.
Collapse
Affiliation(s)
- Kuniyasu Niizuma
- Department of Neurosurgery, Department of Neurology and Neurological Sciences, and Program in Neurosciences, Stanford University School of Medicine, Stanford, CA, USA
| | | | | | | | | | | | | | | |
Collapse
|
33
|
Fasanaro P, Capogrossi MC, Martelli F. Regulation of the endothelial cell cycle by the ubiquitin-proteasome system. Cardiovasc Res 2009; 85:272-80. [PMID: 19617222 DOI: 10.1093/cvr/cvp244] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Degradation of poly-ubiquitinated proteins by the 26S-proteasome complex represents a crucial quantitative control mechanism. The ubiquitin-proteasome system (UPS) plays a pivotal role in the complex molecular network regulating the progression both between and within each cell-cycle phase. Two major complexes are involved: the SKP1-CUL1-F-box-protein complex (SCF) and the anaphase-promoting complex/cyclosome (APC/C). Notwithstanding structural similarities, SCF and APC/C display different cellular functions and mechanisms of action. SCF modulates all cell-cycle stages and plays a prominent role at G1/S transition mainly through three regulatory subunits: Skp2, Fbw7, and beta-TRCP. APC/C, regulated by Cdc20 or Cdh1 subunits, has a crucial role in mitosis. In this review, we will describe how the endothelial cell cycle is regulated by the UPS. We will illustrate the principal SCF- and APC/C-dependent molecular mechanisms that modulate cell growth, allowing a unidirectional cell-cycle progression. Then, we will focus our attention on UPS modulation by oxidative stress, a pathogenic stimulus that causes endothelial dysfunction and is involved in numerous cardiovascular diseases.
Collapse
Affiliation(s)
- Pasquale Fasanaro
- Laboratorio di Patologia Vascolare, Istituto Dermopatico dell'Immacolata-IRCCS, Rome, Italy
| | | | | |
Collapse
|
34
|
Niizuma K, Endo H, Chan PH. Oxidative stress and mitochondrial dysfunction as determinants of ischemic neuronal death and survival. J Neurochem 2009; 109 Suppl 1:133-8. [PMID: 19393019 DOI: 10.1111/j.1471-4159.2009.05897.x] [Citation(s) in RCA: 283] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Mitochondria are the powerhouse of the cell. Their primary physiological function is to generate adenosine triphosphate through oxidative phosphorylation via the electron transport chain. Reactive oxygen species generated from mitochondria have been implicated in acute brain injuries such as stroke and neurodegeneration. Recent studies have shown that mitochondrially-formed oxidants are mediators of molecular signaling, which is implicated in the mitochondria-dependent apoptotic pathway that involves pro- and antiapoptotic protein binding, the release of cytochrome c, and transcription-independent p53 signaling, leading to neuronal death. Oxidative stress and the redox state of ischemic neurons are also implicated in the signaling pathway that involves phosphatidylinositol 3-kinase/Akt and downstream signaling, which lead to neuronal survival. Genetically modified mice or rats that over-express or are deficient in superoxide dismutase have provided strong evidence in support of the role of mitochondrial dysfunction and oxidative stress as determinants of neuronal death/survival after stroke and neurodegeneration.
Collapse
Affiliation(s)
- Kuniyasu Niizuma
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, California 94305-5487, USA
| | | | | |
Collapse
|
35
|
Diederich RS, Mowlavi A, Meldrum G, Medling B, Bueno RA, Neumeister MW. Local cooling provides muscle flaps protection from ischemia-reperfusion injury in the event of venous occlusion during the early reperfusion period. Hand (N Y) 2009; 4:19-23. [PMID: 18814018 PMCID: PMC2654943 DOI: 10.1007/s11552-008-9131-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2008] [Accepted: 08/19/2008] [Indexed: 11/30/2022]
Abstract
Clinicians often place patients in heated rooms following muscle flap transfers. We hypothesize that exposure of flaps to heated room temperatures could result in an unnecessary hyperthermic ischemic insult if the flaps were to be compromised by venous outflow obstruction, while exposure of elective flaps to local cooling during early perfusion may provide protection in the event of venous occlusion. The rat rectus femoris muscle flap was elevated and clamped for 1 h. The muscle was then exposed to various temperatures for 1 h of perfusion followed by complete venous occlusion for 3 h. Occlusion clamps were removed and flaps were allowed to reperfuse for 24 h. Flaps were assessed for muscle necrosis and edema. Venous occluded muscles demonstrated decreased muscle necrosis and edema in the locally cooled group (8.5 +/- 6.7%, 3.06 +/- 0.14; P < 0.001) compared to the room temperature group (76.2 +/- 23.0%, 3.73 +/- 0.13), and the local warming group (97.3 +/- 1.4%, 3.84 +/- 0.29) respectively. No difference was noted in muscle necrosis nor edema amongst non-ischemic muscles irrespective of temperature exposure. These results suggest a beneficial role for exposure of elective flaps to local cooling during the early perfusion period in order to provide protection from ischemia reperfusion injury in the event of a venous occlusion insult. The prophylactic exposure of flaps to local cooling is further supported by the lack of a harmful effect when flaps were not compromised by venous occlusion.
Collapse
Affiliation(s)
- Ryan S. Diederich
- Southern Illinois University School of Medicine, Plastic Surgery Institute, Springfield, IL 62702 USA
| | - Arian Mowlavi
- Southern Illinois University School of Medicine, Plastic Surgery Institute, Springfield, IL 62702 USA
| | - Garth Meldrum
- Southern Illinois University School of Medicine, Plastic Surgery Institute, Springfield, IL 62702 USA
| | - Brad Medling
- Southern Illinois University School of Medicine, Plastic Surgery Institute, Springfield, IL 62702 USA
| | - Reuben A. Bueno
- Southern Illinois University School of Medicine, Plastic Surgery Institute, Springfield, IL 62702 USA
| | - Michael W. Neumeister
- Southern Illinois University School of Medicine, Plastic Surgery Institute, Springfield, IL 62702 USA
| |
Collapse
|
36
|
Wierød L, Rosseland CM, Lindeman B, Oksvold MP, Grøsvik H, Skarpen E, Huitfeldt HS. Activation of the p53-p21(Cip1) pathway is required for CDK2 activation and S-phase entry in primary rat hepatocytes. Oncogene 2007; 27:2763-71. [PMID: 18026139 DOI: 10.1038/sj.onc.1210937] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
p53 plays a major role in the prevention of tumor development. It responds to a range of potentially oncogenic stresses by activating protective mechanisms, most notably cell-cycle arrest and apoptosis. The p53 gene is also induced during normal liver regeneration, and it has been hypothesized that p53 serve as a proliferative 'brake' to control excessive proliferation. However, it has lately been shown that p53 inhibition reduces hepatocyte growth factor-induced DNA synthesis of primary hepatocytes. Here we show that epidermal growth factor (EGF) activated p53 in a phosphatidylinositol-3 kinase-dependent way, and thus induced the cyclin-dependent kinase inhibitor p21(Cip1) in primary rat hepatocytes. p53 inactivation with a dominant-negative mutant (p53(V143A)) attenuated EGF-induced DNA synthesis and was associated with reduced CDK2 phosphorylation and retinoblastoma protein hyperphosphorylation. When p21(Cip1) was ectopically expressed in p53-inactivated cells, these effects were neutralized. In conclusion, our results demonstrate that in normal hepatocytes, EGF-induced expression of p53 is involved in regulating CDK2- and CDK4 activity, through p21(Cip1) expression.
Collapse
Affiliation(s)
- L Wierød
- Laboratory for Toxicopathology, Institute of Pathology, Rikshospitalet Radiumhospitalet Medical Centre, Rikshospitalet University Hospital, University of Oslo, Oslo, Norway.
| | | | | | | | | | | | | |
Collapse
|
37
|
Uo T, Kinoshita Y, Morrison RS. Apoptotic actions of p53 require transcriptional activation of PUMA and do not involve a direct mitochondrial/cytoplasmic site of action in postnatal cortical neurons. J Neurosci 2007; 27:12198-210. [PMID: 17989286 PMCID: PMC6673255 DOI: 10.1523/jneurosci.3222-05.2007] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2005] [Revised: 09/05/2007] [Accepted: 09/05/2007] [Indexed: 11/21/2022] Open
Abstract
Recent studies in non-neuronal cells have shown that the tumor suppressor p53 can promote cell death through a transcription-independent mechanism involving its direct action with a subset of Bcl-2 family member proteins in the cytosol and at the mitochondria. In cultured cortical neurons, however, we could not find evidence supporting a significant contribution of the cytosolic/mitochondrial p53 pathway, and available evidence instead corroborated the requirement for the transcriptional activity of p53. When directly targeted to the cytosol/mitochondria, wild-type p53 lost its apoptosis-inducing activity in neurons but not in non-neuronal cells. The N-terminal p53 fragment (transactivation and proline-rich domains), which induces apoptosis in non-neuronal cells via the cytosolic/mitochondrial pathway, displayed no apoptogenic activity in neurons. In neuronal apoptosis induced by camptothecin or an MDM2 (murine double minute 2) inhibitor, nutlin-3, endogenous p53 protein did not accumulate in the cytosol/mitochondria, and transcriptional inhibition after p53 induction effectively blocked cell death. In addition, overexpression of a dominant-negative form of p53 (R273H) completely suppressed induction of proapoptotic p53 target genes and cell death. PUMA (p53-upregulated modulator of apoptosis) was one such gene induced by camptothecin, and its overexpression was sufficient to induce Bax (Bcl-2-associated X protein)-dependent neuronal death, whereas Noxa was not apoptogenic. These results collectively demonstrate that, in contrast to non-neuronal cells, the apoptotic activity of p53 in postnatal cortical neurons does not rely on its direct action at the cytosol/mitochondria but is exclusively mediated through its transcription-dependent functions. The uniqueness of p53-mediated apoptotic signaling in postnatal cortical neurons was further illustrated by the dispensable function of the proline-rich domain of p53.
Collapse
Affiliation(s)
- Takuma Uo
- Department of Neurological Surgery, University of Washington School of Medicine, Seattle, Washington 98195-6470
| | - Yoshito Kinoshita
- Department of Neurological Surgery, University of Washington School of Medicine, Seattle, Washington 98195-6470
| | - Richard S. Morrison
- Department of Neurological Surgery, University of Washington School of Medicine, Seattle, Washington 98195-6470
| |
Collapse
|
38
|
Endo H, Saito A, Chan PH. Mitochondrial translocation of p53 underlies the selective death of hippocampal CA1 neurons after global cerebral ischaemia. Biochem Soc Trans 2007; 34:1283-6. [PMID: 17073802 DOI: 10.1042/bst0341283] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
p53, a tumour suppressor, is involved in DNA repair and cell death processes and mediates apoptosis in response to death stimuli by transcriptional activation of pro-apoptotic genes and by transcription-independent mechanisms. In the latter process, p53 induces permeabilization of the outer mitochondrial membrane by forming an inhibitory complex with a protective Bcl-2 family protein, resulting in cytochrome c release in several cell line systems. However, it is unclear how the mitochondrial p53 pathway mediates neuronal apoptosis after cerebral ischaemia. We examined interaction between the mitochondrial p53 pathway and vulnerable hippocampal CA1 neurons using a tGCI (transient global cerebral ischaemia) rat model. We showed mitochondrial translocation of p53 and its binding to Bcl-X(L). Mitochondrial p53 translocation, interaction between p53 and Bcl-X(L), and cytochrome c release from mitochondria and subsequent CA1 neuronal death were prevented by pifithrin-alpha, a p53-specific inhibitor. These results suggest that the mitochondrial p53 pathway plays a role in delayed CA1 neuronal death after tGCI.
Collapse
Affiliation(s)
- H Endo
- Department of Neurosurgery, Stanford University School of Medicine, 1201 Welch Road, MSLS #P314, Stanford, CA 94305-5487, USA
| | | | | |
Collapse
|
39
|
Endo H, Kamada H, Nito C, Nishi T, Chan PH. Mitochondrial translocation of p53 mediates release of cytochrome c and hippocampal CA1 neuronal death after transient global cerebral ischemia in rats. J Neurosci 2006; 26:7974-83. [PMID: 16870742 PMCID: PMC6674216 DOI: 10.1523/jneurosci.0897-06.2006] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Although p53 is a key modulator of cellular stress responses, the mechanism of p53-mediated apoptosis is ambiguous. p53 can mediate apoptosis in response to death stimuli by transcriptional activation of proapoptotic genes and transcriptional-independent mechanisms. Recent studies have shown that the p53 protein can directly induce permeabilization of the outer mitochondrial membrane by forming a inhibitory complex with a protective Bcl-2 family protein, resulting in cytochrome c release. However, how the mitochondrial p53 pathway mediates neuronal apoptosis after cerebral ischemia remains unclear. We examined the interaction between the mitochondrial p53 pathway and vulnerable hippocampal CA1 neurons in rats using a transient global cerebral ischemia (tGCI) model. Western blot analysis and immunofluorescent staining revealed mitochondrial p53 translocation after tGCI in the hippocampal CA1 neurons. Coimmunoprecipitation revealed that translocated p53 bound to Bcl-X(L) in the mitochondrial fraction. To examine the effect of a specific p53 inhibitor on the mitochondrial p53 pathway and apoptotic cell death after tGCI, we intravenously administered pifithrin-alpha (PFT). Mitochondrial p53 translocation and interaction between p53 and Bcl-X(L) were prevented by treatment with PFT. Moreover, cytochrome c release from mitochondria and subsequent apoptotic CA1 neuronal death were decreased with PFT treatment. These results suggest that the mitochondrial p53 pathway is one of the novel mechanisms mediating delayed death of vulnerable hippocampal CA1 neurons after tGCI.
Collapse
|