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Cao Z, Mu S, Wang M, Zhang Y, Zou G, Yuan X, Huang Y, Yu S, Zhang J, Zhang C. Succinate pretreatment attenuates intestinal ischemia-reperfusion injury by inhibiting necroptosis and inflammation via upregulating Klf4. Int Immunopharmacol 2023; 120:110425. [PMID: 37285681 DOI: 10.1016/j.intimp.2023.110425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/21/2023] [Accepted: 05/30/2023] [Indexed: 06/09/2023]
Abstract
Intestinal ischemia-reperfusion (I/R) injury is a common pathophysiological process in various diseases, and the disruption of the intestinal barrier composed of tight junction proteins is the initiating factor, which then leads to a large number of bacteria and endotoxins in the intestine into the bloodstream causing stress and distant organ damage. The release of inflammatory mediators and abnormal programmed death of intestinal epithelial cells are important factors of intestinal barrier damage. Succinate is an intermediate product of the tricarboxylic acid cycle with anti-inflammatory and pro-angiogenic activities, but its role in the maintenance of intestinal barrier homeostasis after I/R has not been fully elucidated. In this study, we explored the effect of succinate on intestinal ischemia-reperfusion injury and the possible mechanism of its role by flow cytometry, western blotting, real-time quantitative PCR and immunostaining. The results of pretreatment with succinate in the mouse intestinal I/R model and IEC-6 cells hypoxia-reoxygenation (H/R) model revealed a reduction in tissue damage, necroptosis and associated inflammation due to ischemia-reperfusion. Furthermore, it was found that the protective effect of succinate pretreatment may be associated with the transcriptional upregulation of the inflammatory protein KLF4 and the protective effect of intestinal barrier of succinate was diminished after inhibition of KLF4. Thus, our results suggest that succinate can exert a protective effect in intestinal ischemia-reperfusion injury through upregulation of KLF4 and also demonstrate the potential therapeutic value of succinate pretreatment in acute I/R injury of the intestine.
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Affiliation(s)
- Zhen Cao
- Department of General Surgery, The First Medical Center of Chinese PLA General Hospital, Beijing 100853, China
| | - Silong Mu
- Department of General Surgery, The First Medical Center of Chinese PLA General Hospital, Beijing 100853, China
| | - Maihuan Wang
- Department of General Surgery, The First Medical Center of Chinese PLA General Hospital, Beijing 100853, China
| | - Yun Zhang
- Department of General Surgery, The First Medical Center of Chinese PLA General Hospital, Beijing 100853, China
| | - Guijun Zou
- Department of General Surgery, The First Medical Center of Chinese PLA General Hospital, Beijing 100853, China
| | - Xinpu Yuan
- Department of General Surgery, The First Medical Center of Chinese PLA General Hospital, Beijing 100853, China
| | - Yun Huang
- Department of General Surgery, The First Medical Center of Chinese PLA General Hospital, Beijing 100853, China
| | - Siwang Yu
- State Key Laboratory of Natural and Biomimetic Drugs; Department of Molecular and Cellular Pharmacology, Peking University School of Pharmaceutical Sciences, Beijing 100191, China
| | - Jinming Zhang
- Department of General Surgery, The First Medical Center of Chinese PLA General Hospital, Beijing 100853, China.
| | - Chaojun Zhang
- Department of General Surgery, The First Medical Center of Chinese PLA General Hospital, Beijing 100853, China.
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2
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DDX17 promotes hepatocellular carcinoma progression via inhibiting Klf4 transcriptional activity. Cell Death Dis 2019; 10:814. [PMID: 31653828 PMCID: PMC6814716 DOI: 10.1038/s41419-019-2044-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 09/03/2019] [Accepted: 10/04/2019] [Indexed: 01/08/2023]
Abstract
DEAD box RNA helicase 17 (DDX17) is a transcriptional regulator of several transcription factors, which is more appreciated than its role in RNA metabolism. However, prognostic value and biofunction of DDX17 in HCC remain unclear. Illuminating the mechanism underlying the regulating HCC progression by DDX17 may contribute to therapeutic strategies. In our study, we report for the first time that DDX17 was overexpressed in HCC specimens by using The Cancer Genome Atlas (TCGA) and immunohistochemistry (IHC) and correlated to clinical pathological characteristics and patients' survival. In vitro, DDX17 was ascertained to alter HCC migratory and invasive capacities after overexpression and knockdown in HCC cell lines. Moreover, by performing co-immunoprecipitation (Co-IP) and GST-pull down assay, the physical association between DDX17 and Klf4 was discovered and validated. Additionally, DDX17 could modulate expressions of Klf4 target genes including E-cadherin, MMP2 by inhibiting the promoter activity. The potent correlation between DDX17 and Klf4 target gene expressions was further appraised by a same set of 30 HCC tissues. Besides, we discovered that DDX17 could not deploy its function in regulating Klf4 target gene expressions and HCC progression in Klf4-depletion condition. Intriguingly, DDX17 failed to interact with Klf4 once the zinc-finger domain was deleted and inhibited the binding of Klf4 on MMP-2 promoter. Collectively, our study enucleates novel mechanism of DDX17-mediated oncogenesis by suppressing the transcriptional activity of Klf4 thus is likely to be a therapeutic target in HCC.
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3
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Hodges AJ, Hudson NO, Buck-Koehntop BA. Cys 2His 2 Zinc Finger Methyl-CpG Binding Proteins: Getting a Handle on Methylated DNA. J Mol Biol 2019:S0022-2836(19)30567-4. [PMID: 31628952 DOI: 10.1016/j.jmb.2019.09.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 09/13/2019] [Accepted: 09/16/2019] [Indexed: 12/12/2022]
Abstract
DNA methylation is an essential epigenetic modification involved in the maintenance of genomic stability, preservation of cellular identity, and regulation of the transcriptional landscape needed to maintain cellular function. In an increasing number of disease conditions, DNA methylation patterns are inappropriately distributed in a manner that supports the disease phenotype. Methyl-CpG binding proteins (MBPs) are specialized transcription factors that read and translate methylated DNA signals into recruitment of protein assemblies that can alter local chromatin architecture and transcription. MBPs thus play a key intermediary role in gene regulation for both normal and diseased cells. Here, we highlight established and potential structure-function relationships for the best characterized members of the zinc finger (ZF) family of MBPs in propagating DNA methylation signals into downstream cellular responses. Current and future investigations aimed toward expanding our understanding of ZF MBP cellular roles will provide needed mechanistic insight into normal and disease state functions, as well as afford evaluation for the potential of these proteins as epigenetic-based therapeutic targets.
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Affiliation(s)
- Amelia J Hodges
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, UT, 84112, USA
| | - Nicholas O Hudson
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, UT, 84112, USA
| | - Bethany A Buck-Koehntop
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, UT, 84112, USA.
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4
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Liu S, Xing Y, Lu W, Li S, Tian Z, Xing H, Tang K, Xu Y, Rao Q, Wang M, Wang J. RUNX1 inhibits proliferation and induces apoptosis of t(8;21) leukemia cells via KLF4-mediated transactivation of P57. Haematologica 2019; 104:1597-1607. [PMID: 30792202 PMCID: PMC6669147 DOI: 10.3324/haematol.2018.192773] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 02/20/2019] [Indexed: 12/14/2022] Open
Abstract
RUNX1 is a key transcription factor in hematopoiesis and its disruption is one of the most common aberrations in acute myeloid leukemia. RUNX1 alterations affect its DNA binding capacity and transcriptional activities, leading to the deregulation of transcriptional targets, and abnormal proliferation and differentiation of myeloid cells. Identification of RUNX1 target genes and clarification of their biological functions are of great importance in the search for new therapeutic strategies for RUNX1-altered leukemia. In this study, we identified and confirmed that KLF4, a known tumor suppressor gene, as a direct target of RUNX1, was down-regulated in RUNX1-ETO leukemia. RUNX1 bound to KLF4 promoter in chromatin to activate its transcription, while the leukemogenic RUNX1-ETO fusion protein had little effect on this transactivation. KLF4 was also identified as a novel binding partner of RUNX1. RUNX1 interacted with KLF4 through Runt domain and further co-activated its target genes. However, RUNX1-ETO competed with RUNX1 to bind KLF4 through Runt and ETO domains, and abrogated transcription of KLF4. Finally, overexpression experiments indicated that RUNX1 inhibited proliferation and induced apoptosis of t(8;21) leukemia cells via KLF4-mediated upregulation of P57. These data suggest KLF4 dysregulation mediated by RUNX1-ETO enhances proliferation and retards apoptosis, and provides a potential target for therapy of t(8;21) acute myeloid leukemia.
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Affiliation(s)
- Shuang Liu
- State Key Laboratory of Experimental Hematology
| | - Yanyan Xing
- State Key Laboratory of Experimental Hematology
| | - Wenting Lu
- State Key Laboratory of Experimental Hematology
| | - Shouyun Li
- State Key Laboratory of Experimental Hematology
| | - Zheng Tian
- State Key Laboratory of Experimental Hematology
| | - Haiyan Xing
- State Key Laboratory of Experimental Hematology
| | - Kejing Tang
- State Key Laboratory of Experimental Hematology
| | - Yingxi Xu
- State Key Laboratory of Experimental Hematology
| | - Qing Rao
- State Key Laboratory of Experimental Hematology
| | - Min Wang
- State Key Laboratory of Experimental Hematology
| | - Jianxiang Wang
- State Key Laboratory of Experimental Hematology .,National Clinical Research Center for Blood Diseases, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, P.R. China
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5
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Estrada CC, Paladugu P, Guo Y, Pace J, Revelo MP, Salant DJ, Shankland SJ, D'Agati VD, Mehrotra A, Cardona S, Bialkowska AB, Yang VW, He JC, Mallipattu SK. Krüppel-like factor 4 is a negative regulator of STAT3-induced glomerular epithelial cell proliferation. JCI Insight 2018; 3:98214. [PMID: 29925693 PMCID: PMC6124441 DOI: 10.1172/jci.insight.98214] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 05/14/2018] [Indexed: 01/11/2023] Open
Abstract
Pathologic glomerular epithelial cell (GEC) hyperplasia is characteristic of both rapidly progressive glomerulonephritis (RPGN) and subtypes of focal segmental glomerulosclerosis (FSGS). Although initial podocyte injury resulting in activation of STAT3 signals GEC proliferation in both diseases, mechanisms regulating this are unknown. Here, we show that the loss of Krüppel-like factor 4 (KLF4), a zinc-finger transcription factor, enhances GEC proliferation in both RPGN and FSGS due to dysregulated STAT3 signaling. We observed that podocyte-specific knockdown of Klf4 (C57BL/6J) increased STAT3 signaling and exacerbated crescent formation after nephrotoxic serum treatment. Interestingly, podocyte-specific knockdown of Klf4 in the FVB/N background alone was sufficient to activate STAT3 signaling, resulting in FSGS with extracapillary proliferation, as well as renal failure and reduced survival. In cultured podocytes, loss of KLF4 resulted in STAT3 activation and cell-cycle reentry, leading to mitotic catastrophe. This triggered IL-6 release into the supernatant, which activated STAT3 signaling in parietal epithelial cells. Conversely, either restoration of KLF4 expression or inhibition of STAT3 signaling improved survival in KLF4-knockdown podocytes. Finally, human kidney biopsy specimens with RPGN exhibited reduced KLF4 expression with a concomitant increase in phospho-STAT3 expression as compared with controls. Collectively, these results suggest the essential role of KLF4/STAT3 signaling in podocyte injury and its regulation of aberrant GEC proliferation.
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Affiliation(s)
- Chelsea C Estrada
- Division of Nephrology, Department of Medicine, Stony Brook University, Stony Brook, New York, USA
| | - Praharshasai Paladugu
- Division of Nephrology, Department of Medicine, Stony Brook University, Stony Brook, New York, USA
| | - Yiqing Guo
- Division of Nephrology, Department of Medicine, Stony Brook University, Stony Brook, New York, USA
| | - Jesse Pace
- Division of Nephrology, Department of Medicine, Stony Brook University, Stony Brook, New York, USA
| | - Monica P Revelo
- Department of Pathology, University of Utah, Salt Lake City, Utah, USA
| | - David J Salant
- Division of Nephrology, Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Stuart J Shankland
- Division of Nephrology, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
| | - Vivette D D'Agati
- Department of Pathology, Columbia University, New York, New York, USA
| | - Anita Mehrotra
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA.,Renal Section, James J. Peters VA Medical Center, New York, New York, USA
| | - Stephanie Cardona
- Division of Nephrology, Department of Medicine, Stony Brook University, Stony Brook, New York, USA
| | - Agnieszka B Bialkowska
- Division of Gastroenterology, Department of Medicine, Stony Brook University, Stony Brook, New York, USA
| | - Vincent W Yang
- Division of Gastroenterology, Department of Medicine, Stony Brook University, Stony Brook, New York, USA
| | - John C He
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA.,Renal Section, James J. Peters VA Medical Center, New York, New York, USA
| | - Sandeep K Mallipattu
- Division of Nephrology, Department of Medicine, Stony Brook University, Stony Brook, New York, USA.,Renal Section, Northport VA Medical Center, Northport, New York, USA
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6
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Ghaleb AM, Yang VW. Krüppel-like factor 4 (KLF4): What we currently know. Gene 2017; 611:27-37. [PMID: 28237823 DOI: 10.1016/j.gene.2017.02.025] [Citation(s) in RCA: 340] [Impact Index Per Article: 48.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 02/17/2017] [Accepted: 02/21/2017] [Indexed: 02/06/2023]
Abstract
Krüppel-like factor 4 (KLF4) is an evolutionarily conserved zinc finger-containing transcription factor that regulates diverse cellular processes such as cell growth, proliferation, and differentiation. Since its discovery in 1996, KLF4 has been gaining a lot of attention, particularly after it was shown in 2006 as one of four factors involved in the induction of pluripotent stem cells (iPSCs). Here we review the current knowledge about the different functions and roles of KLF4 in various tissue and organ systems.
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Affiliation(s)
- Amr M Ghaleb
- Department of Medicine, Stony Brook University, Stony Brook, NY 11794, USA
| | - Vincent W Yang
- Department of Medicine, Stony Brook University, Stony Brook, NY 11794, USA; Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY 11794, USA.
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7
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Siu MK, Suau F, Chen WY, Tsai YC, Tsai HY, Yeh HL, Liu YN. KLF4 functions as an activator of the androgen receptor through reciprocal feedback. Oncogenesis 2016; 5:e282. [PMID: 27991915 PMCID: PMC5177777 DOI: 10.1038/oncsis.2016.79] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 10/07/2016] [Accepted: 11/02/2016] [Indexed: 12/17/2022] Open
Abstract
In prostate cancer, Krüppel-like factor 4 (KLF4) depletion occurs frequently, suggesting a role as suppressor tumor. KLF4 is a transcription factor associated with androgen receptor (AR) expression; however, its cellular functions and signaling regulation mechanism remain largely unknown. In this study, we demonstrated that activated AR binds to the KLF4 promoter and enhances KLF4 expression, which reciprocally targets the AR promoter, thus sustaining KLF4 activity. Ectopic KLF4 expression in androgen-independent prostate cancer cells induced AR expression and decreased cell proliferation, invasion and bone metastasis. We previously showed that increased microRNA (miR)-1 expression is associated with reduced bone metastasis of prostate cancer cells. Here we observed that KLF4 targets the primary miR-1-2 stem-loop promoter and stimulates miR-1 expression. In clinical prostate cancer specimens, KLF4 levels were positively correlated with miR-1 and AR levels. These data suggest that the loss of KLF4 expression is one mechanistic link between aggressive prostate cancer progression and low canonical AR output through miR-1 inactivation.
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Affiliation(s)
- M-K Siu
- Program for Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University and Academia Sinica, Taipei, Taiwan.,Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan.,Department of Anesthesiology, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - F Suau
- Department of Microbiology, Faculty of Pharmacy, Dicle University, Diyarbakir, Turkey
| | - W-Y Chen
- Department of Pathology, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.,Department of Pathology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Y-C Tsai
- Program for Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University and Academia Sinica, Taipei, Taiwan.,Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - H-Y Tsai
- Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - H-L Yeh
- Institute of Information System and Applications, National Tsing Hua University, Hsinchu, Taiwan
| | - Y-N Liu
- Program for Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University and Academia Sinica, Taipei, Taiwan.,Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
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8
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Park CS, Shen Y, Lewis A, Lacorazza HD. Role of the reprogramming factor KLF4 in blood formation. J Leukoc Biol 2016; 99:673-85. [DOI: 10.1189/jlb.1ru1215-539r] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 01/22/2016] [Indexed: 12/31/2022] Open
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9
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Wang B, Zhao MZ, Cui NP, Lin DD, Zhang AY, Qin Y, Liu CY, Yan WT, Shi JH, Chen BP. Krüppel-like factor 4 induces apoptosis and inhibits tumorigenic progression in SK-BR-3 breast cancer cells. FEBS Open Bio 2015; 5:147-54. [PMID: 25834779 PMCID: PMC4359971 DOI: 10.1016/j.fob.2015.02.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2014] [Revised: 02/21/2015] [Accepted: 02/24/2015] [Indexed: 12/16/2022] Open
Abstract
Krüppel-like factor 4 (KLF4) functions as either a tumor suppressor or an oncogene in different tissues by regulating the expression of various genes. The aim of this study was to reveal the functions of KLF4 in regulating breast cancer apoptosis, proliferation, and tumorigenic progression. KLF4 expression levels in breast cancer tissues and breast cancer cell lines were found to be much lower than those in nontumorous tissues and a nontransformed mammary epithelial cell line. KLF4 was upregulated in the tumor necrosis factor-α-induced SK-BR-3 breast cancer cell apoptotic process. Overexpression of KLF4 promoted SK-BR-3 breast cancer cell apoptosis and suppressed SK-BR-3 cell tumorigenicity in vivo.
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Affiliation(s)
- Bing Wang
- Department of Oncology, Affiliated Hospital of Hebei University, Baoding 071000, China
| | - Ming-Zhi Zhao
- Department of Oncology, Affiliated Hospital of Hebei University, Baoding 071000, China
| | - Nai-Peng Cui
- Department of Oncology, Affiliated Hospital of Hebei University, Baoding 071000, China
| | - Dan-Dan Lin
- Central Laboratory, Affiliated Hospital of Hebei University, Baoding 071000, China
| | - An-Yi Zhang
- Central Laboratory, Affiliated Hospital of Hebei University, Baoding 071000, China
| | - Yan Qin
- Central Laboratory, Affiliated Hospital of Hebei University, Baoding 071000, China
| | - Cai-Yun Liu
- Department of Oncology, Affiliated Hospital of Hebei University, Baoding 071000, China
| | - Wei-Tao Yan
- Department of Oncology, Affiliated Hospital of Hebei University, Baoding 071000, China
| | - Jian-Hong Shi
- Central Laboratory, Affiliated Hospital of Hebei University, Baoding 071000, China
| | - Bao-Ping Chen
- Department of Oncology, Affiliated Hospital of Hebei University, Baoding 071000, China
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10
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MiR-7 promotes epithelial cell transformation by targeting the tumor suppressor KLF4. PLoS One 2014; 9:e103987. [PMID: 25181544 PMCID: PMC4151986 DOI: 10.1371/journal.pone.0103987] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 07/06/2014] [Indexed: 12/30/2022] Open
Abstract
MicroRNAs (miRNAs) are endogenous small non-coding RNAs that have a pivotal role in the post-transcriptional regulation of gene expression and their misregulation is common in different types of cancer. Although it has been shown that miR-7 plays an oncogenic role in different cellular contexts, the molecular mechanisms by which miR-7 promotes cell transformation are not well understood. Here we show that the transcription factor KLF4 is a direct target of miR-7 and present experimental evidence indicating that the regulation of KLF4 by miR-7 has functional implications in epithelial cell transformation. Stable overexpression of miR-7 into lung and skin epithelial cells enhanced cell proliferation, cell migration and tumor formation. Alteration of these cellular functions by miR-7 resulted from misregulation of KLF4 target genes involved in cell cycle control. miR-7-induced tumors showed decreased p21 and increased Cyclin D levels. Taken together, these findings indicate that miR-7 acts as an oncomiR in epithelial cells in part by directly regulating KLF4 expression. Thus, we conclude that miR-7 acts as an oncomiR in the epithelial cellular context, where through the negative regulation of KLF4-dependent signaling pathways, miR-7 promotes cellular transformation and tumor growth.
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11
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Su C, Sun F, Cunningham RL, Rybalchenko N, Singh M. ERK5/KLF4 signaling as a common mediator of the neuroprotective effects of both nerve growth factor and hydrogen peroxide preconditioning. AGE (DORDRECHT, NETHERLANDS) 2014; 36:9685. [PMID: 25015774 PMCID: PMC4150906 DOI: 10.1007/s11357-014-9685-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 06/26/2014] [Indexed: 05/16/2023]
Abstract
Oxidative stress has long been implicated in the pathogenesis of various neurodegenerative disorders such as Alzheimer's disease and stroke. While high levels of oxidative stress are generally associated with cell death, a slight rise of reactive oxygen species (ROS) levels can be protective by "preconditioning" cells to develop a resistance against subsequent challenges. However, the mechanisms underlying such preconditioning (PC)-induced protection are still poorly understood. Previous studies have supported a role of ERK5 (mitogen-activated protein [MAP] kinase 5) in neuroprotection and ischemic tolerance in the hippocampus. In agreement with these findings, our data suggest that ERK5 mediates both hydrogen peroxide (H2O2)-induced PC as well as nerve growth factor (NGF)-induced neuroprotection. Activation of ERK5 partially rescued pheochromocytoma PC12 cells as well as primary hippocampal neurons from H2O2-caused death, while inhibition of ERK5 abolished NGF or PC-induced protection. These results implicate ERK5 signaling as a common downstream pathway for NGF and PC. Furthermore, both NGF and PC increased the expression of the transcription factor, KLF4, which can initiate an anti-apoptotic response in various cell types. Induction of KLF4 by NGF or PC was blocked by siERK5, suggesting that ERK5 is required in this process. siKLF4 can also attenuate NGF- or PC-induced neuroprotection. Overexpression of active MEK5 or KLF4 in H2O2-stressed cells increased Bcl-2/Bax ratio and the expression of NAIP (neuronal apoptosis inhibitory protein). Taken together, our data suggest that ERK5/KLF4 cascade is a common signaling pathway shared by at least two important mechanisms by which neurons can be protected from cell death.
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Affiliation(s)
- Chang Su
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX, 76107, USA,
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12
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Farooqi AA, Mansoor Q, Ismail M, Bhatti S. Therapeutic Effect of Epigallocatechin-3-gallate (EGCG) and Silibinin on ATM Dynamics in Prostate Cancer Cell Line LNCaP. World J Oncol 2011; 1:242-246. [PMID: 29147215 PMCID: PMC5649750 DOI: 10.4021/wjon248w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/19/2010] [Indexed: 12/03/2022] Open
Abstract
Background Epigallocatechin-3-gallate (EGCG) is a major ingredient of green tea (GT) and silibinin (SB), the active component of Silymarin presumably hold a potential to prevent pathogenomics. Prostate cancer exacerbation is triggered by fusion transcripts formed because of genomic instability induced by juxtapositioning of two genes. This chimeric transcript is implicated in androgen dependent and independent prostate cancer. Tremendous work is done on the characterization of the mediators involved in the disease refractoriness, yet no study has addressed clinical management of these prostate fusion transcripts impressively. Methods An abolished ATM dynamics challenges integrity of DNA. In agreement with this assumption, ATM and DNA-PK were impaired in LNCaP cell line to confirm a tight interaction of these mediators with the expression profile of TMPRSS2-ERG. Abolished ATM enhanced the expression of the fusion transcript. Similarly blunting of DNA-PK downregulated the expression of the fusion transcript giving a notion that DNA-PK is involved in the chromosomal translocation. LNCaP cell lines were analyzed for the effect of EGCG and SB on the expression profile of TMPRSS2-ERG. Results In this particular unprecedented study, treatment of the LNCaP cell line with EGCG and Silibilin recapitulated ATM expression and activity and downregulated the fusion transcript appearance. Conclusions These results underscore the therapeutic effect of EGCG and SB in mitigating the exacerbation of the disease with reference to the fusion transcripts.
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Affiliation(s)
- Ammad Ahmad Farooqi
- Institute of Molecular Biology and Biotechnology (IMBB), The University of Lahore, Pakistan
| | - Qaisar Mansoor
- Institute of Biomedical and Genetic Engineering (IBGE), Islamabad, Pakistan
| | - Muhammad Ismail
- Institute of Biomedical and Genetic Engineering (IBGE), Islamabad, Pakistan
| | - Shahzad Bhatti
- Institute of Molecular Biology and Biotechnology (IMBB), The University of Lahore, Pakistan
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13
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Grabarczyk P, Nähse V, Delin M, Przybylski G, Depke M, Hildebrandt P, Völker U, Schmidt CA. Increased expression of bcl11b leads to chemoresistance accompanied by G1 accumulation. PLoS One 2010; 5. [PMID: 20824091 PMCID: PMC2932720 DOI: 10.1371/journal.pone.0012532] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Accepted: 07/22/2010] [Indexed: 12/11/2022] Open
Abstract
Background The expression of BCL11B was reported in T-cells, neurons and keratinocytes. Aberrations of BCL11B locus leading to abnormal gene transcription were identified in human hematological disorders and corresponding animal models. Recently, the elevated levels of Bcl11b protein have been described in a subset of squameous cell carcinoma cases. Despite the rapidly accumulating knowledge concerning Bcl11b biology, the contribution of this protein to normal or transformed cell homeostasis remains open. Methodology/Principal Findings Here, by employing an overexpression strategy we revealed formerly unidentified features of Bcl11b. Two different T-cell lines were forced to express BCL11B at levels similar to those observed in primary T-cell leukemias. This resulted in markedly increased resistance to radiomimetic drugs while no influence on death-receptor apoptotic pathway was observed. Apoptosis resistance triggered by BCL11B overexpression was accompanied by a cell cycle delay caused by accumulation of cells at G1. This cell cycle restriction was associated with upregulation of CDKN1C (p57) and CDKN2C (p18) cyclin dependent kinase inhibitors. Moreover, p27 and p130 proteins accumulated and the SKP2 gene encoding a protein of the ubiquitin-binding complex responsible for their degradation was repressed. Furthermore, the expression of the MYCN oncogene was silenced which resulted in significant depletion of the protein in cells expressing high BCL11B levels. Both cell cycle restriction and resistance to DNA-damage-induced apoptosis coincided and required the histone deacetylase binding N-terminal domain of Bcl11b. The sensitivity to genotoxic stress could be restored by the histone deacetylase inhibitor trichostatine A. Conclusions The data presented here suggest a potential role of BCL11B in tumor survival and encourage developing Bcl11b-inhibitory approaches as a potential tool to specifically target chemoresistant tumor cells.
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Affiliation(s)
- Piotr Grabarczyk
- Molecular Hematology, Department of Hematology and Oncology, University Greifswald, Greifswald, Germany
| | - Viola Nähse
- Molecular Hematology, Department of Hematology and Oncology, University Greifswald, Greifswald, Germany
| | - Martin Delin
- Molecular Hematology, Department of Hematology and Oncology, University Greifswald, Greifswald, Germany
| | - Grzegorz Przybylski
- Molecular Hematology, Department of Hematology and Oncology, University Greifswald, Greifswald, Germany
- Institute of Human Genetics, Polish Academy of Sciences, Poznan, Poland
| | - Maren Depke
- Department of Functional Genomics, Interfaculty Institute for Genetics and Functional Genomics, Greifswald, Germany
| | - Petra Hildebrandt
- Department of Functional Genomics, Interfaculty Institute for Genetics and Functional Genomics, Greifswald, Germany
| | - Uwe Völker
- Department of Functional Genomics, Interfaculty Institute for Genetics and Functional Genomics, Greifswald, Germany
| | - Christian A. Schmidt
- Molecular Hematology, Department of Hematology and Oncology, University Greifswald, Greifswald, Germany
- * E-mail:
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14
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Lim CB, Ky N, Ng HM, Hamza MS, Yan Zhao. Curcuma wenyujin Extract Induces Apoptosis and Inhibits Proliferation of Human Cervical Cancer Cells In Vitro and In Vivo. Integr Cancer Ther 2010; 9:36-49. [DOI: 10.1177/1534735409359773] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
An essential oil extract, derived from the rhizome of Curcuma wenyujin (CWE), possesses antioxidative, antimicrobial, and anti-inflammatory properties. However, it remains unknown how exactly CWE inhibits tumor growth. In this study, using human cervical cancer HeLa cells, the authors postulated that CWE has the ability to inhibit tumor growth. The study shows that CWE dose-dependently suppressed colony formation and inhibited the proliferation of HeLa cells through blockade of cell cycle progression at G1 phase and apoptosis. CWE-induced G1 arrest was associated with retinoblastoma protein dephosphorylation and reduced amounts of cyclins D1 and D3, and cyclin-dependent kinase 4 and 6 proteins. CWE treatment resulted in apoptosis in HeLa cells as evidenced by morphological changes, caspase activation and PARP cleavage, which can be reversed by a pan-caspase inhibitor. It was observed that CWE treatment activated the mitochondrial apoptotic pathway indicated by a decrease in Mcl-1 and Bcl-xL levels, resulting in mitochondrial membrane potential loss and caspases 9 activation. CWE-treated cells displayed reduced PTEN, AKT, and STAT3 phosphorylation and downregulation of NFκB signaling, providing a mechanism for the G1 arrest and apoptosis observed. Furthermore, CWE inhibited tumor growth of HeLa in a xenograft mouse tumor model, suggesting that CWE inhibited tumorigenesis by inhibiting cell proliferation and inducing apoptosis. These findings are the first to reveal the molecular basis for the anticervical cancer action of CWE. The results suggest that CWE could be developed as a drug for the management of cervical cancer.
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Affiliation(s)
| | - Nung Ky
- Nanyang Technological University, Singapore
| | - Hui-Min Ng
- Nanyang Technological University, Singapore
| | | | - Yan Zhao
- Nanyang Technological University, Singapore,
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