1
|
Kasahara N, Teratani T, Yokota S, Sakuma Y, Sasanuma H, Fujimoto Y, Ijichi T, Urahashi T, Yoshitomi H, Kitayama J, Sata N. Dietary polyamines promote intestinal adaptation in an experimental model of short bowel syndrome. Sci Rep 2024; 14:4605. [PMID: 38409241 PMCID: PMC10897130 DOI: 10.1038/s41598-024-55258-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Accepted: 02/21/2024] [Indexed: 02/28/2024] Open
Abstract
Intestinal adaptation does not necessarily recover absorptive capacity in short bowel syndrome (SBS), sometimes resulting in intestinal failure-associated liver disease (IFALD). Additionally, its therapeutic options remain limited. Polyamines (spermidine and spermine) are known as one of the autophagy inducers and play important roles in promoting the weaning process; however, their impact on intestinal adaptation is unknown. The aim of this study was to investigate the impact of polyamines ingestion on adaptation and hepatic lipid metabolism in SBS. We performed resection of two-thirds of the small intestine in male Lewis rats as an SBS model. They were allocated into three groups and fed different polyamine content diets (0%, 0.01%, 0.1%) for 30 days. Polyamines were confirmed to distribute to remnant intestine, whole blood, and liver. Villous height and number of Ki-67-positive cells in the crypt area increased with the high polyamine diet. Polyamines increased secretory IgA and mucin content in feces, and enhanced tissue Claudin-3 expression. In contrast, polyamines augmented albumin synthesis, mitochondrial DNA copy number, and ATP storage in the liver. Moreover, polyamines promoted autophagy flux and activated AMP-activated protein kinase with suppression of lipogenic gene expression. Polyamines ingestion may provide a new therapeutic option for SBS with IFALD.
Collapse
Affiliation(s)
- Naoya Kasahara
- Department of Surgery, Jichi Medical University, Shimotsuke, Japan
| | - Takumi Teratani
- Division of Translational Research, Jichi Medical University, Shimotsuke, Japan.
| | | | - Yasunaru Sakuma
- Department of Surgery, Jichi Medical University, Shimotsuke, Japan
| | - Hideki Sasanuma
- Department of Surgery, Jichi Medical University, Shimotsuke, Japan
| | - Yasuhiro Fujimoto
- Department of Transplant Surgery, Nagoya University Hospital, Nagoya, Japan
| | - Tetsuo Ijichi
- Division of Translational Research, Jichi Medical University, Shimotsuke, Japan
| | - Taizen Urahashi
- Department of Surgery, Dokkyo Medical University Saitama Medical Center, Koshigaya, Japan
| | - Hideyuki Yoshitomi
- Department of Surgery, Dokkyo Medical University Saitama Medical Center, Koshigaya, Japan
| | - Joji Kitayama
- Department of Surgery, Jichi Medical University, Shimotsuke, Japan
| | - Naohiro Sata
- Department of Surgery, Jichi Medical University, Shimotsuke, Japan
| |
Collapse
|
2
|
Wang SR, Mallard CG, Cairns CA, Chung HK, Yoo D, Jaladanki SK, Xiao L, Wang JY. Stabilization of Cx43 mRNA via RNA-binding protein HuR regulated by polyamines enhances intestinal epithelial barrier function. Am J Physiol Gastrointest Liver Physiol 2023; 325:G518-G527. [PMID: 37788332 PMCID: PMC10894663 DOI: 10.1152/ajpgi.00143.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 08/22/2023] [Accepted: 09/29/2023] [Indexed: 10/05/2023]
Abstract
Gut barrier dysfunction occurs commonly in patients with critical disorders, leading to the translocation of luminal toxic substances and bacteria to the bloodstream. Connexin 43 (Cx43) acts as a gap junction protein and is crucial for intercellular communication and the diffusion of nutrients. The levels of cellular Cx43 are tightly regulated by multiple factors, including polyamines, but the exact mechanism underlying the control of Cx43 expression remains largely unknown. The RNA-binding protein HuR regulates the stability and translation of target mRNAs and is involved in many aspects of intestinal epithelial pathobiology. Here we show that HuR directly bound to Cx43 mRNA via its 3'-untranslated region in intestinal epithelial cells (IECs) and this interaction enhanced Cx43 expression by stabilizing Cx43 mRNA. Depletion of cellular polyamines inhibited the [HuR/Cx43 mRNA] complex and decreased the level of Cx43 protein by destabilizing its mRNA, but these changes were prevented by ectopic overexpression of HuR. Polyamine depletion caused intestinal epithelial barrier dysfunction, which was reversed by ectopic Cx43 overexpression. Moreover, overexpression of checkpoint kinase 2 in polyamine-deficient cells increased the [HuR/Cx43 mRNA] complex, elevated Cx43 levels, and promoted barrier function. These findings indicate that Cx43 mRNA is a novel target of HuR in IECs and that polyamines regulate Cx43 mRNA stability via HuR, thus playing a critical role in the maintenance of intestinal epithelial barrier function.NEW & NOTEWORTHY The current study shows that polyamines stabilize the Cx43 mRNA via HuR, thus enhancing the function of the Cx43-mediated gap junction. These findings suggest that induced Cx43 by HuR plays a critical role in the process by which polyamines regulate intestinal epithelial barrier.
Collapse
Affiliation(s)
- Shelley R Wang
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, United States
| | - Caroline G Mallard
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, United States
| | - Cassandra A Cairns
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, United States
| | - Hee Kyoung Chung
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, United States
| | - Dongyoon Yoo
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, United States
| | - Suraj K Jaladanki
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, United States
| | - Lan Xiao
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, United States
| | - Jian-Ying Wang
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, United States
- Department of Pathology, University of Maryland School of Medicine, Baltimore, Maryland, United States
- Baltimore Veterans Affairs Medical Center, Baltimore, Maryland, United States
| |
Collapse
|
3
|
Ma X, Xiao L, Wen SJ, Yu T, Sharma S, Chung HK, Warner B, Mallard CG, Rao JN, Gorospe M, Wang J. Small noncoding vault RNA2-1 disrupts gut epithelial barrier function via interaction with HuR. EMBO Rep 2023; 24:e54925. [PMID: 36440604 PMCID: PMC9900329 DOI: 10.15252/embr.202254925] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 11/08/2022] [Accepted: 11/10/2022] [Indexed: 11/29/2022] Open
Abstract
Vault RNAs (vtRNAs) are small noncoding RNAs and highly expressed in many eukaryotes. Here, we identified vtRNA2-1 as a novel regulator of the intestinal barrier via interaction with RNA-binding protein HuR. Intestinal mucosal tissues from patients with inflammatory bowel diseases and from mice with colitis or sepsis express increased levels of vtRNAs relative to controls. Ectopically expressed vtRNA2-1 decreases the levels of intercellular junction (IJ) proteins claudin 1, occludin, and E-cadherin and causes intestinal epithelial barrier dysfunction in vitro, whereas vtRNA2-1 silencing promotes barrier function. Increased vtRNA2-1 also decreases IJs in intestinal organoid, inhibits epithelial renewal, and causes Paneth cell defects ex vivo. Elevating the levels of tissue vtRNA2-1 in the intestinal mucosa increases the vulnerability of the gut barrier to septic stress in mice. vtRNA2-1 interacts with HuR and prevents HuR binding to claudin 1 and occludin mRNAs, thus decreasing their translation. These results indicate that vtRNA2-1 impairs intestinal barrier function by repressing HuR-facilitated translation of claudin 1 and occludin.
Collapse
Affiliation(s)
- Xiang‐Xue Ma
- Cell Biology Group, Department of SurgeryUniversity of Maryland School of MedicineBaltimoreMDUSA
- Present address:
Department of Gastroenterology, Xiyuan HospitalChina Academy of Chinese Medical SciencesBeijingChina
| | - Lan Xiao
- Cell Biology Group, Department of SurgeryUniversity of Maryland School of MedicineBaltimoreMDUSA
| | - Susan J Wen
- Cell Biology Group, Department of SurgeryUniversity of Maryland School of MedicineBaltimoreMDUSA
| | - Ting‐Xi Yu
- Cell Biology Group, Department of SurgeryUniversity of Maryland School of MedicineBaltimoreMDUSA
| | - Shweta Sharma
- Cell Biology Group, Department of SurgeryUniversity of Maryland School of MedicineBaltimoreMDUSA
| | - Hee K Chung
- Cell Biology Group, Department of SurgeryUniversity of Maryland School of MedicineBaltimoreMDUSA
| | - Bridgette Warner
- Cell Biology Group, Department of SurgeryUniversity of Maryland School of MedicineBaltimoreMDUSA
| | - Caroline G Mallard
- Cell Biology Group, Department of SurgeryUniversity of Maryland School of MedicineBaltimoreMDUSA
| | - Jaladanki N Rao
- Cell Biology Group, Department of SurgeryUniversity of Maryland School of MedicineBaltimoreMDUSA
- Baltimore Veterans Affairs Medical CenterBaltimoreMDUSA
| | - Myriam Gorospe
- Laboratory of Genetics and GenomicsNational Institute on Aging‐IRP, NIHBaltimoreMDUSA
| | - Jian‐Ying Wang
- Cell Biology Group, Department of SurgeryUniversity of Maryland School of MedicineBaltimoreMDUSA
- Laboratory of Genetics and GenomicsNational Institute on Aging‐IRP, NIHBaltimoreMDUSA
- Department of PathologyUniversity of Maryland School of MedicineBaltimoreMDUSA
| |
Collapse
|
4
|
Li R, Rao JN, Smith AD, Chung HK, Xiao L, Wang JY, Turner DJ. miR-542-5p targets c-myc and negates the cell proliferation effect of SphK1 in intestinal epithelial cells. Am J Physiol Cell Physiol 2023; 324:C565-C572. [PMID: 36622069 PMCID: PMC9942902 DOI: 10.1152/ajpcell.00145.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 12/22/2022] [Accepted: 12/28/2022] [Indexed: 01/10/2023]
Abstract
Intestinal epithelial barrier defects occur commonly during a variety of pathological conditions, though their underlying mechanisms are not completely understood. Sphingosine-1-phosphate (S1P) has been shown to be a critical regulator of proliferation and of maintenance of an intact intestinal epithelial barrier, as is also sphingosine kinase 1 (SphK1), the rate-limiting enzyme for S1P synthesis. SphK1 has been shown to modulate its effect on intestinal epithelial proliferation through increased levels of c-myc. We conducted genome-wide profile analysis to search for differential microRNA expression related to overexpressed SphK1 demonstrating adjusted expression of microRNA 542-5p (miR-542-5p). Here, we show that miR-542-5p is regulated by SphK1 activity and is an effector of c-myc translation that ultimately serves as a critical regulator of the intestinal epithelial barrier. miR-542-5p directly regulates c-myc translation through direct binding to the c-myc mRNA. Exogenous S1P analogs administered in vivo protect murine intestinal barrier from damage due to mesenteric ischemia reperfusion, and damaged intestinal tissue had increased levels of miR-542-5p. These results indicate that miR-542-5p plays a critical role in the regulation of S1P-mediated intestinal barrier function, and may highlight a novel role in potential therapies.
Collapse
Affiliation(s)
- Ruiyun Li
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland
- Baltimore VA Medical Center, Baltimore, Maryland
| | - Jaladanki N Rao
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland
- Baltimore VA Medical Center, Baltimore, Maryland
| | - Alexis D Smith
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland
| | - Hee Kyoung Chung
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland
- Baltimore VA Medical Center, Baltimore, Maryland
| | - Lan Xiao
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland
- Baltimore VA Medical Center, Baltimore, Maryland
| | - Jian-Ying Wang
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland
- Baltimore VA Medical Center, Baltimore, Maryland
- Cell Biology Group, Department of Pathology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Douglas J Turner
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland
- Baltimore VA Medical Center, Baltimore, Maryland
| |
Collapse
|
5
|
Jin H, Chen Y, Ren J, Huang J, Zhao Y, Liu H. TERC suppresses PD-L1 expression by downregulating RNA binding protein HuR. SCIENCE CHINA. LIFE SCIENCES 2022; 65:2505-2516. [PMID: 35661964 DOI: 10.1007/s11427-021-2085-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 03/02/2022] [Indexed: 06/15/2023]
Abstract
TERC is the RNA component of telomerase, and provides a template for TERT to synthesize telomere repeats at chromosome ends. Increasing evidence has revealed that TERC is involved in other biological processes beyond telomerase. Here, we found that the expression level of TERC is negatively correlated with PD-L1 and that ectopic expression of TERC but not TERT in ALT cells significantly inhibits PD-L1, suggesting that TERC suppresses PD-L1 expression in a telomerase-independent manner. Mechanistically, instead of regulating PD-L1 mRNA directly, TERC accelerates PD-L1 mRNA degradation by inhibiting the expression of HuR, which binds to the 3'UTR of PD-L1 mRNA and maintains its stability. We also found that the small molecule AS1842856, a FoxO1 inhibitor, promotes TERC expression and reverses the PD-L1 upregulation caused by chemotherapy, providing a potential combination cancer therapy that avoids cancer immune escape during chemotherapy.
Collapse
Affiliation(s)
- Heping Jin
- MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Yanlian Chen
- MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Jian Ren
- MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Junjiu Huang
- MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Yong Zhao
- MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China
| | - Haiying Liu
- MOE Key Laboratory of Gene Function and Regulation, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510006, China.
| |
Collapse
|
6
|
Hu Antigen R (HuR) Protein Structure, Function and Regulation in Hepatobiliary Tumors. Cancers (Basel) 2022; 14:cancers14112666. [PMID: 35681645 PMCID: PMC9179498 DOI: 10.3390/cancers14112666] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 05/19/2022] [Accepted: 05/23/2022] [Indexed: 12/10/2022] Open
Abstract
Simple Summary Hepatobiliary tumors are a group of primary malignancies encompassing the liver, the intra- and extra-hepatic biliary tracts, and the gall bladder. Within the liver, hepatocellular carcinoma (HCC) is the most common type of primary cancer, which is, also, representing the third-most recurrent cause of cancer-associated death and the sixth-most prevalent type of tumor worldwide, nowadays. Although less frequent, cholangiocarcinoma (CCA) is, currently, a fatal cancer with limited therapeutic options. Here, we review the regulatory role of Hu antigen R (HuR), a ubiquitous member of the ELAV/Hu family of RNA-binding proteins (RBPs), in the pathogenesis, progression, and treatment of HCC and CCA. Overall, HuR is proposed as a valuable diagnostic and prognostic marker, as well as a therapeutic target in hepatobiliary cancers. Therefore, novel therapeutic approaches that can selectively modulate HuR function appear to be highly attractive for the clinical management of these types of tumors. Abstract Hu antigen R (HuR) is a 36-kDa ubiquitous member of the ELAV/Hu family of RNA-binding proteins (RBPs), which plays an important role as a post-transcriptional regulator of specific RNAs under physiological and pathological conditions, including cancer. Herein, we review HuR protein structure, function, and its regulation, as well as its implications in the pathogenesis, progression, and treatment of hepatobiliary cancers. In particular, we focus on hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), tumors where the increased cytoplasmic localization of HuR and activity are proposed, as valuable diagnostic and prognostic markers. An overview of the main regulatory axes involving HuR, which are associated with cell proliferation, invasion, metastasis, apoptosis, and autophagy in HCC, is provided. These include the transcriptional, post-transcriptional, and post-translational modulators of HuR function, in addition to HuR target transcripts. Finally, whereas studies addressing the relevance of targeting HuR in CCA are limited, in the past few years, HuR has emerged as a potential therapeutic target in HCC. In fact, the therapeutic efficacy of some pharmacological inhibitors of HuR has been evaluated, in early experimental models of HCC. We, further, discuss the major findings and future perspectives of therapeutic approaches that specifically block HuR interactions, either with post-translational modifiers or cognate transcripts in hepatobiliary cancers.
Collapse
|
7
|
Ding Y, Zhou DY, Yu H, Zhu T, Guo F, He Y, Guo XL, Lin YJ, Liu YJ, Yu YS. Upregulation of lncRNA NONRATG019935.2 suppresses the p53-mediated apoptosis of renal tubular epithelial cells in septic acute kidney injury. Cell Death Dis 2021; 12:771. [PMID: 34719669 PMCID: PMC8558325 DOI: 10.1038/s41419-021-03953-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 05/05/2021] [Accepted: 05/06/2021] [Indexed: 12/11/2022]
Abstract
Although increasing evidence has confirmed that the apoptosis of renal tubular epithelial cells (RTECs) is a crucial contributor to the onset and development of septic acute kidney injury (AKI), the pathological mechanism by which RTEC apoptosis is upregulated during septic AKI is not entirely clear. In this study, a rat model of septic AKI was induced by a cecal ligation puncture procedure or lipopolysaccharide (LPS) injection. Four differentially expressed long noncoding RNAs (DE-Lncs) in the rat model of septic AKI were determined using RNA-sequencing and verified by qRT-PCR. Among the four DE-Lncs, the expression level of lncRNA NONRATG019935.2 (9935) exhibited the most significant reduction in both septic AKI rats and LPS-treated NRK-52E cells (a rat RTEC line). The overexpression of 9935 suppressed cell apoptosis and p53 protein level in LPS-treated NRK-52E cells, and retarded septic AKI development in the rat model of septic AKI. Mechanistically, 9935 decreased the human antigen R (HuR)-mediated Tp53 mRNA stability by limiting the combination of HuR and the 3'UTR region of Tp53 mRNA in RTECs. The overexpression of HuR abrogated the inhibitory effect of pcDNA-9935 on the LPS-induced apoptosis of NRK-52E and rat primary RTECs. In conclusion, 9935 exerts its role in septic AKI by suppressing the p53-mediated apoptosis of RTECs, and this essential role of 9935 relies on its destructive effect on HuR-mediated Tp53 mRNA stability.
Collapse
Affiliation(s)
- Ying Ding
- Department of Intensive Care Unit, Sir Run Run Shaw Hospital Xiasha Campus, Zhejiang University School of Medicine, 310018, Hangzhou, Zhejiang, China.
| | - Dao-Yang Zhou
- Department of Emergency, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 310016, Hangzhou, Zhejiang, China
| | - Hong Yu
- Department of General Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 310016, Hangzhou, Zhejiang, China
| | - Tao Zhu
- Department of Intensive Care Unit, Sir Run Run Shaw Hospital Xiasha Campus, Zhejiang University School of Medicine, 310018, Hangzhou, Zhejiang, China
| | - Feng Guo
- Department of Intensive Care Unit, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, 310016, Hangzhou, Zhejiang, China
| | - Yang He
- Department of Emergency, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 310016, Hangzhou, Zhejiang, China
| | - Xiu-Liu Guo
- Department of Intensive Care Unit, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, 310016, Hangzhou, Zhejiang, China
| | - Yong-Jun Lin
- Department of Intensive Care Unit, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, 310016, Hangzhou, Zhejiang, China
| | - Yu-Jiao Liu
- Department of Intensive Care Unit, Sir Run Run Shaw Hospital Xiasha Campus, Zhejiang University School of Medicine, 310018, Hangzhou, Zhejiang, China
| | - Yun-Song Yu
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 310016, Hangzhou, Zhejiang, China
| |
Collapse
|
8
|
Rao JN, Xiao L, Wang JY. Polyamines in Gut Epithelial Renewal and Barrier Function. Physiology (Bethesda) 2021; 35:328-337. [PMID: 32783609 DOI: 10.1152/physiol.00011.2020] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Polyamines regulate a variety of physiological functions and are involved in pathogenesis of diverse human diseases. The epithelium of the mammalian gut mucosa is a rapidly self-renewing tissue in the body, and its homeostasis is preserved through well-controlled mechanisms. Here, we highlight the roles of cellular polyamines in maintaining the integrity of the gut epithelium, focusing on the emerging evidence of polyamines in the regulation of gut epithelial renewal and barrier function. Gut mucosal growth depends on the available supply of polyamines to the dividing cells in the crypts, and polyamines are also essential for normal gut epithelial barrier function. Polyamines modulate expression of various genes encoding growth-associated proteins and intercellular junctions via distinct mechanisms involving RNA-binding proteins and noncoding RNAs. With the rapid advance of polyamine biology, polyamine metabolism and transport are promising therapeutic targets in our efforts to protect the gut epithelium and barrier function in patients with critical illnesses.
Collapse
Affiliation(s)
- Jaladanki N Rao
- Department of Surgery,Cell Biology Group, University of Maryland School of Medicine, Baltimore, Maryland.,Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Lan Xiao
- Department of Surgery,Cell Biology Group, University of Maryland School of Medicine, Baltimore, Maryland.,Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Jian-Ying Wang
- Department of Surgery,Cell Biology Group, University of Maryland School of Medicine, Baltimore, Maryland.,Baltimore Veterans Affairs Medical Center, Baltimore, Maryland.,Department of Pathology, University of Maryland School of Medicine, Baltimore, Maryland
| |
Collapse
|
9
|
Daks A, Petukhov A, Fedorova O, Shuvalov O, Kizenko A, Tananykina E, Vasileva E, Semenov O, Bottrill A, Barlev N. The RNA-binding protein HuR is a novel target of Pirh2 E3 ubiquitin ligase. Cell Death Dis 2021; 12:581. [PMID: 34091597 PMCID: PMC8179929 DOI: 10.1038/s41419-021-03871-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 05/18/2021] [Accepted: 05/24/2021] [Indexed: 11/24/2022]
Abstract
The RING-finger protein Pirh2 is a p53 family-specific E3 ubiquitin ligase. Pirh2 also ubiquitinates several other important cellular factors and is involved in carcinogenesis. However, its functional role in other cellular processes is poorly understood. To address this question, we performed a proteomic search for novel interacting partners of Pirh2. Using the GST-pulldown approach combined with LC-MS/MS, we revealed 225 proteins that interacted with Pirh2. We found that, according to the GO description, a large group of Pirh2-associated proteins belonged to the RNA metabolism group. Importantly, one of the identified proteins from that group was an RNA-binding protein ELAVL1 (HuR), which is involved in the regulation of splicing and protein stability of several oncogenic proteins. We demonstrated that Pirh2 ubiquitinated the HuR protein facilitating its proteasome-mediated degradation in cells. Importantly, the Pirh2-mediated degradation of HuR occurred in response to heat shock, thereby affecting the survival rate of HeLa cells under elevated temperature. Functionally, Pirh2-mediated degradation of HuR augmented the level of c-Myc expression, whose RNA level is otherwise attenuated by HuR. Taken together, our data indicate that HuR is a new target of Pirh2 and this functional interaction contributes to the heat-shock response of cancer cells affecting their survival.
Collapse
Affiliation(s)
- Alexandra Daks
- Institute of Cytology, Russian Academy of Sciences, 194064, St Petersburg, Russian Federation.
| | - Alexey Petukhov
- Institute of Cytology, Russian Academy of Sciences, 194064, St Petersburg, Russian Federation.,Almazov National Medical Research Centre, Institute of Hematology, 197341, St Petersburg, Russian Federation
| | - Olga Fedorova
- Institute of Cytology, Russian Academy of Sciences, 194064, St Petersburg, Russian Federation
| | - Oleg Shuvalov
- Institute of Cytology, Russian Academy of Sciences, 194064, St Petersburg, Russian Federation
| | - Alena Kizenko
- Institute of Cytology, Russian Academy of Sciences, 194064, St Petersburg, Russian Federation
| | - Elizaveta Tananykina
- Institute of Cytology, Russian Academy of Sciences, 194064, St Petersburg, Russian Federation
| | - Elena Vasileva
- Institute of Cytology, Russian Academy of Sciences, 194064, St Petersburg, Russian Federation
| | - Oleg Semenov
- Institute of Cytology, Russian Academy of Sciences, 194064, St Petersburg, Russian Federation
| | - Andrew Bottrill
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Nickolai Barlev
- Institute of Cytology, Russian Academy of Sciences, 194064, St Petersburg, Russian Federation. .,Moscow Institute of Physics and Technology, 141700, Dolgoprudny, Moscow Region, Russian Federation.
| |
Collapse
|
10
|
Li J, Meng Y, Wu X, Sun Y. Polyamines and related signaling pathways in cancer. Cancer Cell Int 2020; 20:539. [PMID: 33292222 PMCID: PMC7643453 DOI: 10.1186/s12935-020-01545-9] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 09/08/2020] [Indexed: 02/06/2023] Open
Abstract
Polyamines are aliphatic compounds with more than two amino groups that play various important roles in human cells. In cancer, polyamine metabolism dysfunction often occurs, and regulatory mechanisms of polyamine. This review summarizes the existing research on the metabolism and transport of polyamines to study the association of oncogenes and related signaling pathways with polyamines in tumor cells. Drugs that regulate enzymes have been developed for cancer treatment, and in the future, more attention should be paid to treatment strategies that simultaneously modulate polyamine metabolism and carcinogenic signaling pathways. In addition, the polyamine pathway is a potential target for cancer chemoprevention. As an irreversible suicide inhibitor of the ornithine decarboxylase (a vital enzyme of polyamine synthesis), Difluoro-methylornithine had been shown to have the chemoprevention effect on cancer. Therefore, we summarized and analyzed the chemoprophylaxis effect of the difluoromethylornithine in this systematic review.
Collapse
Affiliation(s)
- Jiajing Li
- Department of Otorhinolaryngology-Head and Neck Surgery, China-Japan Union Hospital, Jilin University, Changchun, Jilin Province, China.,Department of Pathophysiology, Prostate Diseases Prevention and Treatment Research Center, College of Basic Medical Science, Jilin University, Changchun, China
| | - Yan Meng
- Department of Pathophysiology, Prostate Diseases Prevention and Treatment Research Center, College of Basic Medical Science, Jilin University, Changchun, China
| | - Xiaolin Wu
- Department of Pathophysiology, Prostate Diseases Prevention and Treatment Research Center, College of Basic Medical Science, Jilin University, Changchun, China
| | - Yuxin Sun
- Department of Otorhinolaryngology-Head and Neck Surgery, China-Japan Union Hospital, Jilin University, Changchun, Jilin Province, China.
| |
Collapse
|
11
|
Zhang Y, Cai JZ, Xiao L, Chung HK, Ma XX, Chen LL, Rao JN, Wang JY. RNA-binding protein HuR regulates translation of vitamin D receptor modulating rapid epithelial restitution after wounding. Am J Physiol Cell Physiol 2020; 319:C208-C217. [PMID: 32432928 DOI: 10.1152/ajpcell.00009.2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Homeostasis of the intestinal epithelium is tightly regulated by numerous extracellular and intracellular factors including vitamin D and the vitamin D receptor (VDR). VDR is highly expressed in the intestinal epithelium and is implicated in many aspects of gut mucosal pathophysiology, but the exact mechanism that controls VDR expression remains largely unknown. The RNA-binding protein human antigen R (HuR) regulates the stability and translation of target mRNAs and thus modulates various cellular processes and functions. Here we report a novel role of HuR in the posttranscriptional control of VDR expression in the intestinal epithelium. The levels of VDR in the intestinal mucosa decreased significantly in mice with ablated HuR, compared with control mice. HuR silencing in cultured intestinal epithelial cells (IECs) also reduced VDR levels, whereas HuR overexpression increased VDR abundance; neither intervention changed cellular Vdr mRNA content. Mechanistically, HuR bound to Vdr mRNA via its 3'-untranslated region (UTR) and enhanced VDR translation in IECs. Moreover, VDR silencing not only inhibited IEC migration over the wounded area in control cells but also prevented the increased migration in cells overexpressing HuR, although it did not alter IEC proliferation in vitro and growth of intestinal organoids ex vivo. The human intestinal mucosa from patients with inflammatory bowel diseases exhibited decreased levels of both HuR and VDR. These results indicate that HuR enhances VDR translation by directly interacting with its mRNA via 3'-UTR and that induced VDR by HuR is crucial for rapid intestinal epithelial restitution after wounding.
Collapse
Affiliation(s)
- Yunzhan Zhang
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland.,Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Jia-Zhong Cai
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland.,Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Lan Xiao
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland.,Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Hee K Chung
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland.,Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Xiang-Xue Ma
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland.,Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Lin-Lin Chen
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland.,Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Jaladanki N Rao
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland.,Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Jian-Ying Wang
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland.,Baltimore Veterans Affairs Medical Center, Baltimore, Maryland.,Department of Pathology, University of Maryland School of Medicine, Baltimore, Maryland
| |
Collapse
|
12
|
Li XX, Xiao L, Chung HK, Ma XX, Liu X, Song JL, Jin CZ, Rao JN, Gorospe M, Wang JY. Interaction between HuR and circPABPN1 Modulates Autophagy in the Intestinal Epithelium by Altering ATG16L1 Translation. Mol Cell Biol 2020; 40:e00492-19. [PMID: 31932481 PMCID: PMC7048268 DOI: 10.1128/mcb.00492-19] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 11/12/2019] [Accepted: 01/03/2020] [Indexed: 12/19/2022] Open
Abstract
Intestinal epithelial autophagy is crucial for host defense against invasive pathogens, and defects in this process occur frequently in patients with inflammatory bowel disease (IBD) and other mucosal disorders, but the exact mechanism that activates autophagy is poorly defined. Here, we investigated the role of RNA-binding protein HuR (human antigen R) in the posttranscriptional control of autophagy-related genes (ATGs) in the intestinal epithelium. We found that targeted deletion of HuR in intestinal epithelial cells (IECs) specifically decreased the levels of ATG16L1 in the intestinal mucosa. Intestinal mucosa from patients with IBD exhibited reduced levels of both HuR and ATG16L1. HuR directly interacted with Atg16l1 mRNA via its 3' untranslated region and enhanced ATG16L1 translation, without affecting Atg16l1 mRNA stability. Circular RNA circPABPN1 blocked HuR binding to Atg16l1 mRNA and lowered ATG16L1 production. HuR silencing in cultured IECs also prevented rapamycin-induced autophagy, which was abolished by overexpressing ATG16L1. These findings indicate that HuR regulates autophagy by modulating ATG16L1 translation via interaction with circPABPN1 in the intestinal epithelium.
Collapse
Affiliation(s)
- Xiao-Xue Li
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Baltimore Veterans Affairs Medical Center, Baltimore, Maryland, USA
| | - Lan Xiao
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Baltimore Veterans Affairs Medical Center, Baltimore, Maryland, USA
| | - Hee Kyoung Chung
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Baltimore Veterans Affairs Medical Center, Baltimore, Maryland, USA
| | - Xiang-Xue Ma
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Baltimore Veterans Affairs Medical Center, Baltimore, Maryland, USA
| | - Xiangzheng Liu
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Baltimore Veterans Affairs Medical Center, Baltimore, Maryland, USA
| | - Jia-Le Song
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Baltimore Veterans Affairs Medical Center, Baltimore, Maryland, USA
| | - Cindy Z Jin
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Baltimore Veterans Affairs Medical Center, Baltimore, Maryland, USA
| | - Jaladanki N Rao
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Baltimore Veterans Affairs Medical Center, Baltimore, Maryland, USA
| | - Myriam Gorospe
- Laboratory of Genetics and Genomics, National Institute on Aging Intramural Research Program, NIH, Baltimore, Maryland, USA
| | - Jian-Ying Wang
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Baltimore Veterans Affairs Medical Center, Baltimore, Maryland, USA
- Department of Pathology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| |
Collapse
|
13
|
Andrade D, Mehta M, Griffith J, Oh S, Corbin J, Babu A, De S, Chen A, Zhao YD, Husain S, Roy S, Xu L, Aube J, Janknecht R, Gorospe M, Herman T, Ramesh R, Munshi A. HuR Reduces Radiation-Induced DNA Damage by Enhancing Expression of ARID1A. Cancers (Basel) 2019; 11:cancers11122014. [PMID: 31847141 PMCID: PMC6966656 DOI: 10.3390/cancers11122014] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 11/25/2019] [Accepted: 11/29/2019] [Indexed: 12/11/2022] Open
Abstract
Tumor suppressor ARID1A, a subunit of the chromatin remodeling complex SWI/SNF, regulates cell cycle progression, interacts with the tumor suppressor TP53, and prevents genomic instability. In addition, ARID1A has been shown to foster resistance to cancer therapy. By promoting non-homologous end joining (NHEJ), ARID1A enhances DNA repair. Consequently, ARID1A has been proposed as a promising therapeutic target to sensitize cancer cells to chemotherapy and radiation. Here, we report that ARID1A is regulated by human antigen R (HuR), an RNA-binding protein that is highly expressed in a wide range of cancers and enables resistance to chemotherapy and radiation. Our results indicate that HuR binds ARID1A mRNA, thereby increasing its stability in breast cancer cells. We further find that ARID1A expression suppresses the accumulation of DNA double-strand breaks (DSBs) caused by radiation and can rescue the loss of radioresistance triggered by HuR inhibition, suggesting that ARID1A plays an important role in HuR-driven resistance to radiation. Taken together, our work shows that HuR and ARID1A form an important regulatory axis in radiation resistance that can be targeted to improve radiotherapy in breast cancer patients.
Collapse
Affiliation(s)
- Daniel Andrade
- Department of Radiation Oncology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (D.A.); (M.M.); (J.G.); (T.H.)
- Stephenson Cancer Center, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (S.O.); (A.B.); (Y.D.Z.); (R.J.); (R.R.)
| | - Meghna Mehta
- Department of Radiation Oncology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (D.A.); (M.M.); (J.G.); (T.H.)
- Stephenson Cancer Center, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (S.O.); (A.B.); (Y.D.Z.); (R.J.); (R.R.)
| | - James Griffith
- Department of Radiation Oncology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (D.A.); (M.M.); (J.G.); (T.H.)
| | - Sangphil Oh
- Stephenson Cancer Center, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (S.O.); (A.B.); (Y.D.Z.); (R.J.); (R.R.)
- Department of Cell Biology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Joshua Corbin
- Department of Pathology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (J.C.)
| | - Anish Babu
- Stephenson Cancer Center, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (S.O.); (A.B.); (Y.D.Z.); (R.J.); (R.R.)
- Department of Pathology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (J.C.)
| | - Supriyo De
- National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA; (S.D.); (M.G.)
| | - Allshine Chen
- Department of Biostatistics and Epidemiology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA;
| | - Yan D. Zhao
- Stephenson Cancer Center, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (S.O.); (A.B.); (Y.D.Z.); (R.J.); (R.R.)
- Department of Biostatistics and Epidemiology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA;
| | - Sanam Husain
- Department of Pathology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (J.C.)
| | - Sudeshna Roy
- Division of Chemical Biology and Medicinal Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA (J.A.)
| | - Liang Xu
- Department of Molecular Biosciences, University of Kansas Medical Center, Kansas City, KS 66160, USA;
| | - Jeffrey Aube
- Division of Chemical Biology and Medicinal Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA (J.A.)
| | - Ralf Janknecht
- Stephenson Cancer Center, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (S.O.); (A.B.); (Y.D.Z.); (R.J.); (R.R.)
- Department of Cell Biology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- Department of Pathology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (J.C.)
| | - Myriam Gorospe
- National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA; (S.D.); (M.G.)
| | - Terence Herman
- Department of Radiation Oncology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (D.A.); (M.M.); (J.G.); (T.H.)
- Stephenson Cancer Center, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (S.O.); (A.B.); (Y.D.Z.); (R.J.); (R.R.)
| | - Rajagopal Ramesh
- Stephenson Cancer Center, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (S.O.); (A.B.); (Y.D.Z.); (R.J.); (R.R.)
- Department of Pathology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (J.C.)
- Graduate Program in Biomedical Sciences, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Anupama Munshi
- Department of Radiation Oncology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (D.A.); (M.M.); (J.G.); (T.H.)
- Stephenson Cancer Center, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; (S.O.); (A.B.); (Y.D.Z.); (R.J.); (R.R.)
- Correspondence: ; Tel.: +1-405-271-6102; Fax: +1-405-271-2141
| |
Collapse
|
14
|
Chen X, Yang Z, Hu H, Duan W, Wang A, Dong Y, Gao W, Deng S, Cheng B, Li J, Sun N, Cheng Z, Guo W, Li Y, Gao Y. Differentiation and Proliferation of Intestinal Stem Cells and its Underlying Regulated Mechanisms during Weaning. Curr Protein Pept Sci 2019; 20:690-695. [DOI: 10.2174/1389203720666190125101834] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 12/30/2018] [Accepted: 01/13/2019] [Indexed: 11/22/2022]
Abstract
Weaning is a stressful event associated with gastrointestinal disorders and increased disease
susceptibility. Many studies have reported the changes that happened in the gut of various mammals such
as pigs and rats after weaning. These findings suggest that the development of intestinal tract mainly is
affected at the time of weaning through interfering in the differentiation and proliferation of intestinal
stem cells. Weaning stress stimulates the rapid differentiation and proliferation of intestinal stem cells in
order to adjust to changes caused by weaning, which are mainly manifested as deeper crypt depth and
decreased intestine villus height. However, the accelerated cellular process may lead to an increase in
the proportion of immature intestinal epithelial cells and goblet cells, which affect intestinal permeability
and reduce the gut-barrier function against toxins and pathogens. This review briefly describes the effects
coforticotrophin-releasing factor (CRF), epidermal growth factor (EGF) and polyamines on the differentiation
and proliferation of intestinal stem cells after weaning and discusses its possible underlying regulatory
mechanisms. Firstly, weaning stress activates CRF to binds its receptors, which induces proinflammatory
responses and promote rapid differentiation and proliferation of intestinal stem cells to a
larger fraction of immature intestinal epithelial cells and goblet cells. Secondly, the lack of EGF after
weaning inhibits the expression of goblet cell maturation factors and makes it difficult for goblet cells
and intestinal epithelial cells to mature. Finally, diet and endogenous synthesis lead to excessive polyamines
in the intestine, which promote the proliferation of intestinal stem cells by regulating the expression
of human antigen R (HuR) and other related genes at the time of weaning.
Collapse
Affiliation(s)
- Xi Chen
- Piwei Institute, Guangzhou University of Chinese Medicine, Guangzhou, 510405, China
| | - Zehong Yang
- Piwei Institute, Guangzhou University of Chinese Medicine, Guangzhou, 510405, China
| | - Huiling Hu
- Piwei Institute, Guangzhou University of Chinese Medicine, Guangzhou, 510405, China
| | - Wentao Duan
- Institute of Clinical Pharmacology, Guangzhou University of Chinese Medicine, Guangzhou, 510405, China
| | - Aiping Wang
- Piwei Institute, Guangzhou University of Chinese Medicine, Guangzhou, 510405, China
| | - Yanbin Dong
- Piwei Institute, Guangzhou University of Chinese Medicine, Guangzhou, 510405, China
| | - Weihang Gao
- Piwei Institute, Guangzhou University of Chinese Medicine, Guangzhou, 510405, China
| | - Song Deng
- Piwei Institute, Guangzhou University of Chinese Medicine, Guangzhou, 510405, China
| | - Bo Cheng
- Piwei Institute, Guangzhou University of Chinese Medicine, Guangzhou, 510405, China
| | - Jiali Li
- Piwei Institute, Guangzhou University of Chinese Medicine, Guangzhou, 510405, China
| | - Nannan Sun
- Piwei Institute, Guangzhou University of Chinese Medicine, Guangzhou, 510405, China
| | - Zhibin Cheng
- College of Animal Science and Technology, Yunnan Agricultural University, Kunming, Yunnan, 650201, China
| | - Wenfeng Guo
- Piwei Institute, Guangzhou University of Chinese Medicine, Guangzhou, 510405, China
| | - Yanwu Li
- Piwei Institute, Guangzhou University of Chinese Medicine, Guangzhou, 510405, China
| | - Yong Gao
- Piwei Institute, Guangzhou University of Chinese Medicine, Guangzhou, 510405, China
| |
Collapse
|
15
|
Liu L, Xiao L, Chung HK, Kwon MS, Li XX, Wu N, Rao JN, Wang JY. RNA-Binding Protein HuR Regulates Rac1 Nucleocytoplasmic Shuttling Through Nucleophosmin in the Intestinal Epithelium. Cell Mol Gastroenterol Hepatol 2019; 8:475-486. [PMID: 31195150 PMCID: PMC6718926 DOI: 10.1016/j.jcmgh.2019.06.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 06/03/2019] [Accepted: 06/03/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS The mammalian intestinal epithelium is a rapidly self-renewing tissue in the body, and its homeostasis is tightly regulated via well-controlled mechanisms. The RNA-binding protein HuR is essential for maintaining gut epithelial integrity, and targeted deletion of HuR in intestinal epithelial cells (IECs) disrupts mucosal regeneration and delays repair after injury. Here, we defined the role of HuR in regulating subcellular distribution of small guanosine triphosphatase Rac1 and investigated the implication of nucleophosmin (NPM) as a molecular chaperone in this process. METHODS Studies were conducted in intestinal epithelial tissue-specific HuR knockout (IE-HuR-/-) mice and cultured IEC-6 cells, derived from rat small intestinal crypts. Functions of HuR and NPM in vitro were investigated via their gene silencing and overexpression. RESULTS The abundance of cytoplasmic Rac1 in the small intestinal mucosa increased significantly in IE-HuR-/- mice, although HuR deletion did not alter total Rac1 levels. HuR silencing in cultured IECs also increased the cytoplasmic Rac1 levels, without an effect on whole-cell Rac1 content. In addition, HuR deficiency in the intestinal epithelium decreased the levels of NPM in IE-HuR-/- mice and cultured IECs. NPM physically interacted with Rac1 and formed the NPM/Rac1 complex. NPM silencing decreased the NPM/Rac1 association and inhibited nuclear accumulation of Rac1, along with an increase in cytoplasmic abundances of Rac1. In contrast, ectopically expressed NPM enhanced Rac1 nuclear translocation and restored Rac1 subcellular localization to near normal in HuR-deficient cells. CONCLUSIONS These results indicate that HuR regulates Rac1 nucleocytoplasmic shuttling in the intestinal epithelium by altering NPM expression.
Collapse
Affiliation(s)
- Lan Liu
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland,Research Service, Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Lan Xiao
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland,Research Service, Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Hee K. Chung
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland,Research Service, Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Min S. Kwon
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland,Research Service, Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Xiao-Xue Li
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland,Research Service, Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Na Wu
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland,Research Service, Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Jaladanki N. Rao
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland,Research Service, Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Jian-Ying Wang
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland,Research Service, Baltimore Veterans Affairs Medical Center, Baltimore, Maryland,Department of Pathology, University of Maryland School of Medicine, Baltimore, Maryland,Correspondence Address correspondence to: Jian-Ying Wang, MD, PhD, Baltimore Veterans Affairs Medical Center (112), 10 North Greene Street, Baltimore, Maryland 21201. fax: (410) 706-1049.
| |
Collapse
|
16
|
Arruabarrena-Aristorena A, Zabala-Letona A, Carracedo A. Oil for the cancer engine: The cross-talk between oncogenic signaling and polyamine metabolism. SCIENCE ADVANCES 2018; 4:eaar2606. [PMID: 29376126 PMCID: PMC5783676 DOI: 10.1126/sciadv.aar2606] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 12/28/2017] [Indexed: 05/09/2023]
Abstract
The study of metabolism has provided remarkable information about the biological basis and therapeutic weaknesses of cancer cells. Classic biochemistry established the importance of metabolic alterations in tumor biology and revealed the importance of various metabolite families to the tumorigenic process. We have evidence of the central role of polyamines, small polycatonic metabolites, in cell proliferation and cancer growth from these studies. However, how cancer cells activate this metabolic pathway and the molecular cues behind the oncogenic action of polyamines has remained largely obscure. In contrast to the view of metabolites as fuel (anabolic intermediates) for cancer cells, polyamines are better defined as the oil that lubricates the cancer engine because they affect the activity of biological processes. Modern research has brought back to the limelight this metabolic pathway, providing a strong link between genetic, metabolic, and signaling events in cancer. In this review, we enumerate and discuss current views of the regulation and activity of polyamine metabolism in tumor cell biology.
Collapse
Affiliation(s)
| | - Amaia Zabala-Letona
- CIC bioGUNE, Bizkaia Technology Park, 801A Building, 48160 Derio, Bizkaia, Spain
- CIBERONC Centro de Investigación Biomédica en Red de Cáncer, Avenida Monforte de Lemos, Madrid, Spain
| | - Arkaitz Carracedo
- CIC bioGUNE, Bizkaia Technology Park, 801A Building, 48160 Derio, Bizkaia, Spain
- CIBERONC Centro de Investigación Biomédica en Red de Cáncer, Avenida Monforte de Lemos, Madrid, Spain
- Ikerbasque, Basque Foundation for Science, 48011 Bilbao, Spain
- Biochemistry and Molecular Biology Department, University of the Basque Country (UPV/EHU), P.O. Box 644, E-48080 Bilbao, Spain
| |
Collapse
|
17
|
Cooperative Repression of Insulin-Like Growth Factor Type 2 Receptor Translation by MicroRNA 195 and RNA-Binding Protein CUGBP1. Mol Cell Biol 2017; 37:MCB.00225-17. [PMID: 28716948 DOI: 10.1128/mcb.00225-17] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 07/06/2017] [Indexed: 12/14/2022] Open
Abstract
Insulin-like growth factor type 2 (IGF2) receptor (IGF2R) recognizes mannose 6-phosphate-containing molecules and IGF2 and plays an important role in many pathophysiological processes, including gut mucosal adaptation. However, the mechanisms that control cellular IGF2R abundance are poorly known. MicroRNAs (miRNAs) and RNA-binding proteins (RBPs) critically regulate gene expression programs in mammalian cells by modulating the stability and translation of target mRNAs. Here we report that miRNA 195 (miR-195) and RBP CUG-binding protein 1 (CUGBP1) jointly regulate IGF2R expression at the posttranscriptional level in intestinal epithelial cells. Both miR-195 and CUGBP1 interacted with the 3' untranslated region (3'-UTR) of Igf2r mRNA, and the association of CUGBP1 with Igf2r mRNA enhanced miR-195 binding to Igf2r mRNA. Ectopically expressed CUGBP1 and miR-195 repressed IGF2R translation cooperatively without altering the stability of Igf2r mRNA. Importantly, the miR-195- and CUGBP1-repressed levels of cellular IGF2R led to a disruption in the structure of the trans-Golgi network. These findings indicate that IGF2R expression is controlled posttranscriptionally by two factors that associate with Igf2r mRNA and suggest that miR-195 and CUGBP1 dampen IGF signaling by inhibiting IGF2R translation.
Collapse
|
18
|
HuR Enhances Early Restitution of the Intestinal Epithelium by Increasing Cdc42 Translation. Mol Cell Biol 2017; 37:MCB.00574-16. [PMID: 28031329 DOI: 10.1128/mcb.00574-16] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 12/21/2016] [Indexed: 12/27/2022] Open
Abstract
The mammalian intestinal mucosa exhibits a spectrum of responses after acute injury and repairs itself rapidly to restore the epithelial integrity. The RNA-binding protein HuR regulates the stability and translation of target mRNAs and is involved in many aspects of gut epithelium homeostasis, but its exact role in the regulation of mucosal repair after injury remains unknown. We show here that HuR is essential for early intestinal epithelial restitution by increasing the expression of cell division control protein 42 (Cdc42) at the posttranscriptional level. HuR bound to the Cdc42 mRNA via its 3' untranslated region, and this association specifically enhanced Cdc42 translation without an effect on the Cdc42 mRNA level. Intestinal epithelium-specific HuR knockout not only decreased Cdc42 levels in mucosal tissues, but it also inhibited repair of damaged mucosa induced by mesenteric ischemia/reperfusion in the small intestine and by dextran sulfate sodium in the colon. Furthermore, Cdc42 silencing prevented HuR-mediated stimulation of cell migration over the wounded area by altering the subcellular distribution of F-actin. These results indicate that HuR promotes early intestinal mucosal repair after injury by increasing Cdc42 translation and demonstrate the importance of HuR deficiency in the pathogenesis of delayed mucosal healing in certain pathological conditions.
Collapse
|
19
|
Xu Y, Chen J, Xiao L, Chung HK, Zhang Y, Robinson JC, Rao JN, Wang JY. Transcriptional regulation of importin-α1 by JunD modulates subcellular localization of RNA-binding protein HuR in intestinal epithelial cells. Am J Physiol Cell Physiol 2016; 311:C874-C883. [PMID: 27733365 DOI: 10.1152/ajpcell.00209.2016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 10/10/2016] [Indexed: 01/23/2023]
Abstract
The RNA-binding protein HuR is crucial for normal intestinal mucosal regeneration by modulating the stability and translation of target mRNAs, but the exact mechanism underlying HuR trafficking between the cytoplasm and nucleus remains largely unknown. Here we report a novel function of transcription factor JunD in the regulation of HuR subcellular localization through the control of importin-α1 expression in intestinal epithelial cells (IECs). Ectopically expressed JunD specifically inhibited importin-α1 at the transcription level, and this repression is mediated via interaction with CREB-binding site that was located at the proximal region of importin-α1 promoter. Reduction in the levels of importin-α1 by JunD increased cytoplasmic levels of HuR, although it failed to alter whole cell HuR levels. Increased levels of endogenous JunD by depleting cellular polyamines also inhibited importin-α1 expression and increased cytoplasmic HuR levels, whereas JunD silencing rescued importin-α1 expression and enhanced HuR nuclear translocation in polyamine-deficient cells. Moreover, importin-α1 silencing protected IECs against apoptosis, which was prevented by HuR silencing. These results indicate that JunD regulates HuR subcellular distribution by downregulating importin-α1, thus contributing to the maintenance of gut epithelium homeostasis.
Collapse
Affiliation(s)
- Yan Xu
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland.,Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Jie Chen
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland.,Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Lan Xiao
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland.,Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Hee Kyoung Chung
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland.,Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Yuan Zhang
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland.,Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Joseph C Robinson
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland.,Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Jaladanki N Rao
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland.,Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Jian-Ying Wang
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland; .,Department of Pathology, University of Maryland School of Medicine, Baltimore, Maryland; and.,Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| |
Collapse
|
20
|
Ahuja D, Goyal A, Ray PS. Interplay between RNA-binding protein HuR and microRNA-125b regulates p53 mRNA translation in response to genotoxic stress. RNA Biol 2016; 13:1152-1165. [PMID: 27592685 PMCID: PMC5100343 DOI: 10.1080/15476286.2016.1229734] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Tumor suppressor protein p53 plays a crucial role in maintaining genomic integrity in response to DNA damage. Regulation of translation of p53 mRNA is a major mode of regulation of p53 expression under genotoxic stress. The AU/U-rich element-binding protein HuR has been shown to bind to p53 mRNA 3′UTR and enhance translation in response to DNA-damaging UVC radiation. On the other hand, the microRNA miR-125b is reported to repress p53 expression and stress-induced apoptosis. Here, we show that UVC radiation causes an increase in miR-125b level in a biphasic manner, as well as nuclear cytoplasmic translocation of HuR. Binding of HuR to the p53 mRNA 3′UTR, especially at a site adjacent to the miR-125b target site, causes dissociation of the p53 mRNA from the RNA-induced silencing complex (RISC) and inhibits the miR-125b-mediated translation repression of p53. HuR prevents the oncogenic effect of miR-125b by reversing the decrease in apoptosis and increase in cell proliferation caused by the overexpression of miR-125b. The antagonistic interplay between miR-125b and HuR might play an important role in fine-tuning p53 gene expression at the post-transcriptional level, and thereby regulate the cellular response to genotoxic stress.
Collapse
Affiliation(s)
- Deepika Ahuja
- a Department of Biological Sciences , Indian Institute of Science Education and Research , Kolkata, Mohanpur, Nadia , West Bengal , India
| | - Ashish Goyal
- a Department of Biological Sciences , Indian Institute of Science Education and Research , Kolkata, Mohanpur, Nadia , West Bengal , India
| | - Partho Sarothi Ray
- a Department of Biological Sciences , Indian Institute of Science Education and Research , Kolkata, Mohanpur, Nadia , West Bengal , India
| |
Collapse
|
21
|
Nowotarski SL, Origanti S, Sass-Kuhn S, Shantz LM. Destabilization of the ornithine decarboxylase mRNA transcript by the RNA-binding protein tristetraprolin. Amino Acids 2016; 48:2303-11. [PMID: 27193233 DOI: 10.1007/s00726-016-2261-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Accepted: 05/12/2016] [Indexed: 01/25/2023]
Abstract
Ornithine decarboxylase (ODC) is the first and usually rate-limiting enzyme in the polyamine biosynthetic pathway. In a normal physiological state, ODC is tightly regulated. However, during neoplastic transformation, ODC expression becomes upregulated. The studies described here show that the ODC mRNA transcript is destabilized by the RNA-binding protein tristetraprolin (TTP). We show that TTP is able to bind to the ODC mRNA transcript in both non-transformed RIE-1 cells and transformed Ras12V cells. Moreover, using mouse embryonic fibroblast cell lines that are devoid of a functional TTP protein, we demonstrate that in the absence of TTP both ODC mRNA stability and ODC enzyme activity increase when compared to wild-type cells. Finally, we show that the ODC 3' untranslated region contains cis acting destabilizing elements that are affected by, but not solely dependent on, TTP expression. Together, these data support the hypothesis that TTP plays a role in the post-transcriptional regulation of the ODC mRNA transcript.
Collapse
Affiliation(s)
- Shannon L Nowotarski
- Division of Science, The Pennsylvania State University Berks Campus, Reading, PA, 19610, USA.
| | - Sofia Origanti
- Department of Biological Sciences, Marquette University, Milwaukee, WI, USA
| | - Suzanne Sass-Kuhn
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Lisa M Shantz
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA, USA
| |
Collapse
|
22
|
Post-transcriptional regulation of Wnt co-receptor LRP6 and RNA-binding protein HuR by miR-29b in intestinal epithelial cells. Biochem J 2016; 473:1641-9. [PMID: 27089893 PMCID: PMC4888462 DOI: 10.1042/bcj20160057] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 04/05/2016] [Indexed: 02/07/2023]
Abstract
MicroRNAs (miRNAs) control gene expression by binding to their target mRNAs for degradation and/or translation repression and are implicated in many aspects of cellular physiology. Our previous study shows that miR-29b acts as a biological repressor of intestinal mucosal growth, but its exact downstream targets remain largely unknown. In the present study, we found that mRNAs, encoding Wnt co-receptor LRP6 (low-density lipoprotein-receptor-related protein 6) and RNA-binding protein (RBP) HuR, are novel targets of miR-29b in intestinal epithelial cells (IECs) and that expression of LRP6 and HuR is tightly regulated by miR-29b at the post-transcriptional level. miR-29b interacted with both Lrp6 and HuR mRNAs via their 3′-UTRs and inhibited LRP6 and HuR expression by destabilizing Lrp6 and HuR mRNAs and repressing their translation. Studies using heterologous reporter constructs revealed a greater repressive effect of miR-29b through a single binding site in the Lrp6 or HuR 3′-UTR, whereas deletion mutation of this site prevented miR-29b-induced repression of LRP6 and HuR expression. Repression of HuR by miR-29b in turn also contributed to miR-29b-induced LRP6 inhibition, since ectopic overexpression of HuR in cells overexpressing miR-29b restored LRP6 expression to near normal levels. Taken together, our results suggest that miR-29b inhibits expression of LRP6 and HuR post-transcriptionally, thus playing a role in the regulation of IEC proliferation and intestinal epithelial homoeostasis.
Collapse
|
23
|
Motawi TMK, Sadik NAH, Shaker OG, Ghaleb MH. Elevated serum microRNA-122/222 levels are potential diagnostic biomarkers in Egyptian patients with chronic hepatitis C but not hepatic cancer. Tumour Biol 2016; 37:9865-74. [DOI: 10.1007/s13277-016-4884-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 01/18/2016] [Indexed: 12/12/2022] Open
|
24
|
Xiao L, Rao JN, Cao S, Liu L, Chung HK, Zhang Y, Zhang J, Liu Y, Gorospe M, Wang JY. Long noncoding RNA SPRY4-IT1 regulates intestinal epithelial barrier function by modulating the expression levels of tight junction proteins. Mol Biol Cell 2015; 27:617-26. [PMID: 26680741 PMCID: PMC4750922 DOI: 10.1091/mbc.e15-10-0703] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 12/09/2015] [Indexed: 12/21/2022] Open
Abstract
Epithelial cells line the intestinal mucosa and form an important barrier to a wide array of noxious substances in the lumen. Disruption of the barrier integrity occurs commonly in various pathologies. Long noncoding RNAs (lncRNAs) control diverse biological processes, but little is known about the role of lncRNAs in regulation of the gut permeability. Here we show that the lncRNA SPRY4-IT1 regulates the intestinal epithelial barrier function by altering expression of tight junction (TJ) proteins. SPRY4-IT1 silencing led to dysfunction of the epithelial barrier in cultured cells by decreasing the stability of mRNAs encoding TJ proteins claudin-1, claudin-3, occludin, and JAM-1 and repressing their translation. In contrast, increasing the levels of SPRY4-IT1 in the intestinal mucosa protected the gut barrier in mice exposed to septic stress by increasing the abundance of TJ proteins. SPRY4-IT1 directly interacted with TJ mRNAs, and this process was enhanced through the association with the RNA-binding protein HuR. Of interest, the intestinal mucosa from patients with increased gut permeability exhibited a decrease in the levels of SPRY4-IT1. These findings highlight a novel role for SPRY4-IT1 in controlling the intestinal epithelial barrier and define a mechanism by which SPRY4-IT1 modulates TJ expression by altering the stability and translation of TJ mRNAs.
Collapse
Affiliation(s)
- Lan Xiao
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201 Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201
| | - Jaladanki N Rao
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201 Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201
| | - Shan Cao
- Department of -Gastroenterology, People's Hospital, Peking University, Beijing 100044, China
| | - Lan Liu
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201 Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201
| | - Hee Kyoung Chung
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201 Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201
| | - Yun Zhang
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201 Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201
| | - Jennifer Zhang
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201 Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201
| | - Yulan Liu
- Department of -Gastroenterology, People's Hospital, Peking University, Beijing 100044, China
| | - Myriam Gorospe
- Laboratory of Genetics, National Institute on Aging-Intramural Research Program, National Institutes of Health, Baltimore, MD 21224
| | - Jian-Ying Wang
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201 Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201 Department of Pathology, University of Maryland School of Medicine, Baltimore, MD 21201
| |
Collapse
|
25
|
Zhang X, Devany E, Murphy MR, Glazman G, Persaud M, Kleiman FE. PARN deadenylase is involved in miRNA-dependent degradation of TP53 mRNA in mammalian cells. Nucleic Acids Res 2015; 43:10925-38. [PMID: 26400160 PMCID: PMC4678859 DOI: 10.1093/nar/gkv959] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 09/13/2015] [Indexed: 01/10/2023] Open
Abstract
mRNA deadenylation is under the control of cis-acting regulatory elements, which include AU-rich elements (AREs) and microRNA (miRNA) targeting sites, within the 3' untranslated region (3' UTRs) of eukaryotic mRNAs. Deadenylases promote miRNA-induced mRNA decay through their interaction with miRNA-induced silencing complex (miRISC). However, the role of poly(A) specific ribonuclease (PARN) deadenylase in miRNA-dependent mRNA degradation has not been elucidated. Here, we present evidence that not only ARE- but also miRNA-mediated pathways are involved in PARN-mediated regulation of the steady state levels of TP53 mRNA, which encodes the tumor suppressor p53. Supporting this, Argonaute-2 (Ago-2), the core component of miRISC, can coexist in complexes with PARN resulting in the activation of its deadenylase activity. PARN regulates TP53 mRNA stability through not only an ARE but also an adjacent miR-504/miR-125b-targeting site in the 3' UTR. More importantly, we found that miR-125b-loaded miRISC contributes to the specific recruitment of PARN to TP53 mRNA, and that can be reverted by the ARE-binding protein HuR. Together, our studies provide new insights into the role of PARN in miRNA-dependent control of mRNA decay and into the mechanisms behind the regulation of p53 expression.
Collapse
Affiliation(s)
- Xiaokan Zhang
- Chemistry Department, Belfer Research Building, Hunter College and Graduate Center, City University of New York, New York, NY 10021, USA
| | - Emral Devany
- Chemistry Department, Belfer Research Building, Hunter College and Graduate Center, City University of New York, New York, NY 10021, USA Department of Biological Sciences, Kingsborough Community College, City University of New York, 2001 Oriental Boulevard, Brooklyn, NY 11235, USA
| | - Michael R Murphy
- Chemistry Department, Belfer Research Building, Hunter College and Graduate Center, City University of New York, New York, NY 10021, USA
| | - Galina Glazman
- Chemistry Department, Belfer Research Building, Hunter College and Graduate Center, City University of New York, New York, NY 10021, USA
| | - Mirjana Persaud
- Chemistry Department, Belfer Research Building, Hunter College and Graduate Center, City University of New York, New York, NY 10021, USA
| | - Frida E Kleiman
- Chemistry Department, Belfer Research Building, Hunter College and Graduate Center, City University of New York, New York, NY 10021, USA
| |
Collapse
|
26
|
Yu TX, Gu BL, Yan JK, Zhu J, Yan WH, Chen J, Qian LX, Cai W. CUGBP1 and HuR regulate E-cadherin translation by altering recruitment of E-cadherin mRNA to processing bodies and modulate epithelial barrier function. Am J Physiol Cell Physiol 2015; 310:C54-65. [PMID: 26491048 DOI: 10.1152/ajpcell.00112.2015] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 10/14/2015] [Indexed: 01/01/2023]
Abstract
The effectiveness and stability of epithelial barrier depend on apical junctional complexes, which consist of tight junctions (TJs) and adherens junctions (AJs). E-cadherin is the primary component of AJs, and it is essential for maintenance of cell-to-cell interactions and regulates the epithelial barrier. However, the exact mechanism underlying E-cadherin expression, particularly at the posttranscriptional level, remains largely unknown. RNA-binding proteins CUG-binding protein 1 (CUGBP1) and HU antigen R (HuR) are highly expressed in the intestinal epithelial tissues and modulate the stability and translation of target mRNAs. Here, we present evidence that CUGBP1 and HuR interact directly with the 3'-untranslated region of E-cadherin mRNA and regulate E-cadherin translation. CUGBP1 overexpression in Caco-2 cells inhibited E-cadherin translation by increasing the recruitment of E-cadherin mRNA to processing bodies (PBs), thus resulting in an increase in paracellular permeability. Overexpression of HuR exhibited an opposite effect on E-cadherin expression by preventing the translocation of E-cadherin mRNA to PBs and therefore prevented CUGBP1-induced repression of E-cadherin expression. Elevation of HuR also abolished the CUGBP1-induced epithelial barrier dysfunction. These findings indicate that CUGBP1 and HuR negate each other's effects in regulating E-cadherin translation by altering the recruitment of E-cadherin mRNA to PBs and play an important role in the regulation of intestinal barrier integrity under various pathophysiological conditions.
Collapse
Affiliation(s)
- Ting-Xi Yu
- Xin Hua Hospital Affiliated to School of Medicine, Shanghai JiaoTong University, Shanghai, China; and Shanghai Key Laboratory of Pediatric Gastroenterology and Nutrition, Shanghai Institute for Pediatric Research, Shanghai, China
| | - Bei-Lin Gu
- Xin Hua Hospital Affiliated to School of Medicine, Shanghai JiaoTong University, Shanghai, China; and Shanghai Key Laboratory of Pediatric Gastroenterology and Nutrition, Shanghai Institute for Pediatric Research, Shanghai, China
| | - Jun-Kai Yan
- Xin Hua Hospital Affiliated to School of Medicine, Shanghai JiaoTong University, Shanghai, China; and Shanghai Key Laboratory of Pediatric Gastroenterology and Nutrition, Shanghai Institute for Pediatric Research, Shanghai, China
| | - Jie Zhu
- Xin Hua Hospital Affiliated to School of Medicine, Shanghai JiaoTong University, Shanghai, China; and Shanghai Key Laboratory of Pediatric Gastroenterology and Nutrition, Shanghai Institute for Pediatric Research, Shanghai, China
| | - Wei-Hui Yan
- Xin Hua Hospital Affiliated to School of Medicine, Shanghai JiaoTong University, Shanghai, China; and Shanghai Key Laboratory of Pediatric Gastroenterology and Nutrition, Shanghai Institute for Pediatric Research, Shanghai, China
| | - Jie Chen
- Xin Hua Hospital Affiliated to School of Medicine, Shanghai JiaoTong University, Shanghai, China; and
| | - Lin-Xi Qian
- Xin Hua Hospital Affiliated to School of Medicine, Shanghai JiaoTong University, Shanghai, China; and Shanghai Key Laboratory of Pediatric Gastroenterology and Nutrition, Shanghai Institute for Pediatric Research, Shanghai, China
| | - Wei Cai
- Xin Hua Hospital Affiliated to School of Medicine, Shanghai JiaoTong University, Shanghai, China; and Shanghai Key Laboratory of Pediatric Gastroenterology and Nutrition, Shanghai Institute for Pediatric Research, Shanghai, China
| |
Collapse
|
27
|
Huang K, Dong B, Wang Y, Tian T, Zhang B. MicroRNA-519 enhances HL60 human acute myeloid leukemia cell line proliferation by reducing the expression level of RNA-binding protein human antigen R. Mol Med Rep 2015; 12:7830-6. [PMID: 26499919 PMCID: PMC4758332 DOI: 10.3892/mmr.2015.4455] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Accepted: 07/03/2015] [Indexed: 11/30/2022] Open
Abstract
Previous studies have demonstrated that microRNAs (miRs) are involved in cell apoptosis. However, the role of miR-519 in acute myeloid leukemia (AML) has yet to be elucidated. The present study identified the effects of miR-519 on HL60 human acute myeloid leukemia cell growth and apoptosis. The expression levels of miR-519 were examined in AML cells, as well as AML tissue samples. Furthermore, cell viability and apoptosis were examined in HL60 cells transfected with miR-519 mimics, miR-519 inhibitors or a negative control. In addition, the effects of human antigen R (HuR) on cell apoptosis were investigated using specific small interfering RNA targeting HuR. The results demonstrated that the expression levels of miR-519 were significantly increased in the AML cells and the tissue samples, suggesting that miR-519 may contribute to abnormal HL60 cell proliferation. Upregulation of miR-519 expression decreased HL60 cell viability and induced cell apoptosis. Furthermore, knockdown of HuR reduced cell migration and enhanced cell apoptosis. The results of the present study indicate that miR-519 may contribute to HL60 cell apoptosis by regulating the expression of HuR.
Collapse
Affiliation(s)
- Kebin Huang
- Nuclear Medicine Department, The Third Hospital of Chinese People's Liberation Army, Baoji, Shanxi 721004, P.R. China
| | - Bingwei Dong
- Department of Pathology, The Central Hospital of Xianyang, Xianyang, Shaanxi 710065, P.R. China
| | - Yueyue Wang
- Department of Pathology, The Second Affiliated Hospital of Medicine College, Shaanxi University of Chinese Medicine, Xianyang, Shaanxi 100044, P.R. China
| | - Tao Tian
- Department of Pathology, The Second Affiliated Hospital of Medicine College, Shaanxi University of Chinese Medicine, Xianyang, Shaanxi 100044, P.R. China
| | - Biying Zhang
- Clinical Laboratory, People's Hospital of Tongchuan, Tongchuan, Shaanxi 727500, P.R. China
| |
Collapse
|
28
|
Liu L, Ouyang M, Rao JN, Zou T, Xiao L, Chung HK, Wu J, Donahue JM, Gorospe M, Wang JY. Competition between RNA-binding proteins CELF1 and HuR modulates MYC translation and intestinal epithelium renewal. Mol Biol Cell 2015; 26:1797-810. [PMID: 25808495 PMCID: PMC4436827 DOI: 10.1091/mbc.e14-11-1500] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 03/16/2015] [Indexed: 12/17/2022] Open
Abstract
The mammalian intestinal epithelium is one of the most rapidly self-renewing tissues in the body, and its integrity is preserved through strict regulation. The RNA-binding protein (RBP) ELAV-like family member 1 (CELF1), also referred to as CUG-binding protein 1 (CUGBP1), regulates the stability and translation of target mRNAs and is implicated in many aspects of cellular physiology. We show that CELF1 competes with the RBP HuR to modulate MYC translation and regulates intestinal epithelial homeostasis. Growth inhibition of the small intestinal mucosa by fasting in mice was associated with increased CELF1/Myc mRNA association and decreased MYC expression. At the molecular level, CELF1 was found to bind the 3'-untranslated region (UTR) of Myc mRNA and repressed MYC translation without affecting total Myc mRNA levels. HuR interacted with the same Myc 3'-UTR element, and increasing the levels of HuR decreased CELF1 binding to Myc mRNA. In contrast, increasing the concentrations of CELF1 inhibited formation of the [HuR/Myc mRNA] complex. Depletion of cellular polyamines also increased CELF1 and enhanced CELF1 association with Myc mRNA, thus suppressing MYC translation. Moreover, ectopic CELF1 overexpression caused G1-phase growth arrest, whereas CELF1 silencing promoted cell proliferation. These results indicate that CELF1 represses MYC translation by decreasing Myc mRNA association with HuR and provide new insight into the molecular functions of RBPs in the regulation of intestinal mucosal growth.
Collapse
Affiliation(s)
- Lan Liu
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201 Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201
| | - Miao Ouyang
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201 Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201
| | - Jaladanki N Rao
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201 Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201
| | - Tongtong Zou
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201 Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201
| | - Lan Xiao
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201 Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201
| | - Hee Kyoung Chung
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201 Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201
| | - Jing Wu
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201 Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201
| | - James M Donahue
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201 Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201
| | - Myriam Gorospe
- Laboratory of Genetics and Genomics, National Institute on Aging-Intramural Research Program, National Institutes of Health, Baltimore, MD 21224
| | - Jian-Ying Wang
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201 Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201 Department of Pathology, University of Maryland School of Medicine, Baltimore, MD 21201
| |
Collapse
|
29
|
Zou T, Rao JN, Liu L, Xiao L, Chung HK, Li Y, Chen G, Gorospe M, Wang JY. JunD enhances miR-29b levels transcriptionally and posttranscriptionally to inhibit proliferation of intestinal epithelial cells. Am J Physiol Cell Physiol 2015; 308:C813-24. [PMID: 25788572 DOI: 10.1152/ajpcell.00027.2015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 03/14/2015] [Indexed: 12/28/2022]
Abstract
Through its actions as component of the activating protein-1 (AP-1) transcription factor, JunD potently represses cell proliferation. Here we report a novel function of JunD in the regulation of microRNA expression in intestinal epithelial cells (IECs). Ectopically expressed JunD specifically increased the expression of primary and mature forms of miR-29b, whereas JunD silencing inhibited miR-29b expression. JunD directly interacted with the miR-29b1 promoter via AP-1-binding sites, whereas mutation of AP-1 sites from the miR-29b1 promoter prevented JunD-mediated transcriptional activation of the miR-29b1 gene. JunD also enhanced formation of the Drosha microprocessor complex, thus further promoting miR-29b biogenesis. Cellular polyamines were found to regulate miR-29b expression by altering JunD abundance, since the increase in miR-29b expression levels in polyamine-deficient cells was abolished by JunD silencing. In addition, miR-29b silencing prevented JunD-induced repression of IEC proliferation. Our findings indicate that JunD activates miR-29b by enhancing its transcription and processing, which contribute to the inhibitory effect of JunD on IEC growth and maintenance of gut epithelium homeostasis.
Collapse
Affiliation(s)
- Tongtong Zou
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland; Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Jaladanki N Rao
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland; Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Lan Liu
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland; Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Lan Xiao
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland; Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Hee Kyoung Chung
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland; Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Yanwu Li
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland; Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Gang Chen
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland; Baltimore Veterans Affairs Medical Center, Baltimore, Maryland
| | - Myriam Gorospe
- Laboratory of Genetics and Genomics, National Institute on Aging-Intramural Research Program, National Institutes of Health, Baltimore, Maryland; and
| | - Jian-Ying Wang
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland; Baltimore Veterans Affairs Medical Center, Baltimore, Maryland; Department of Pathology, University of Maryland School of Medicine, Baltimore, Maryland
| |
Collapse
|
30
|
Modulation by miR-29b of intestinal epithelium homoeostasis through the repression of menin translation. Biochem J 2015; 465:315-23. [PMID: 25317587 DOI: 10.1042/bj20141028] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Menin regulates distinct cellular functions by regulating gene transcription through its interaction with partner transcription factors, but the exact mechanisms that control menin levels remain largely unknown. In the present study we report that Men1 mRNA, encoding menin, is a novel target of miR-29b and that miR-29b/Men1 mRNA association regulates menin expression post-transcriptionally in rat intestinal epithelial cells (IECs). Overexpression of a miR-29b precursor lowered the levels of Men1 mRNA modestly, but reduced new synthesis of menin robustly; conversely, antagonism of miR-29b enhanced menin protein synthesis and steady-state levels. The repressive effect of miR-29b on menin expression was mediated through a single binding site in the coding region of Men1 mRNA, because point mutation of this site prevented miR-29b-induced repression of menin translation. Increasing cellular polyamines due to overexpression of ornithine decarboxylase (ODC) enhanced menin translation by reducing miR-29b, whereas polyamine depletion by inhibiting ODC increased it, thus suppressing menin expression. Moreover, an increase in menin abundance in an miR-29b-silenced population of IECs led to increased sensitivity to apoptosis, which was prevented by silencing menin. These findings indicate that miR-29b represses translation of Men1 mRNA, in turn affecting intestinal epithelial homoeostasis by altering IEC apoptosis.
Collapse
|
31
|
Liu L, Christodoulou-Vafeiadou E, Rao JN, Zou T, Xiao L, Chung HK, Yang H, Gorospe M, Kontoyiannis D, Wang JY. RNA-binding protein HuR promotes growth of small intestinal mucosa by activating the Wnt signaling pathway. Mol Biol Cell 2014; 25:3308-18. [PMID: 25165135 PMCID: PMC4214778 DOI: 10.1091/mbc.e14-03-0853] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Inhibition of growth of the intestinal epithelium, a rapidly self-renewing tissue, is commonly found in various critical disorders. The RNA-binding protein HuR is highly expressed in the gut mucosa and modulates the stability and translation of target mRNAs, but its exact biological function in the intestinal epithelium remains unclear. Here, we investigated the role of HuR in intestinal homeostasis using a genetic model and further defined its target mRNAs. Targeted deletion of HuR in intestinal epithelial cells caused significant mucosal atrophy in the small intestine, as indicated by decreased cell proliferation within the crypts and subsequent shrinkages of crypts and villi. In addition, the HuR-deficient intestinal epithelium also displayed decreased regenerative potential of crypt progenitors after exposure to irradiation. HuR deficiency decreased expression of the Wnt coreceptor LDL receptor-related protein 6 (LRP6) in the mucosal tissues. At the molecular level, HuR was found to bind the Lrp6 mRNA via its 3'-untranslated region and enhanced LRP6 expression by stabilizing Lrp6 mRNA and stimulating its translation. These results indicate that HuR is essential for normal mucosal growth in the small intestine by altering Wnt signals through up-regulation of LRP6 expression and highlight a novel role of HuR deficiency in the pathogenesis of intestinal mucosal atrophy under pathological conditions.
Collapse
Affiliation(s)
- Lan Liu
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201 Veterans Affairs Medical Center, Baltimore, MD 21201
| | | | - Jaladanki N Rao
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201 Veterans Affairs Medical Center, Baltimore, MD 21201
| | - Tongtong Zou
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201 Veterans Affairs Medical Center, Baltimore, MD 21201
| | - Lan Xiao
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201 Veterans Affairs Medical Center, Baltimore, MD 21201
| | - Hee Kyoung Chung
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201 Veterans Affairs Medical Center, Baltimore, MD 21201
| | - Hong Yang
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201 Veterans Affairs Medical Center, Baltimore, MD 21201
| | - Myriam Gorospe
- Laboratory of Genetics, National Institute on Aging-Intramural Research Program, National Institutes of Health, Baltimore, MD 21224
| | | | - Jian-Ying Wang
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201 Veterans Affairs Medical Center, Baltimore, MD 21201; Department of Pathology, University of Maryland School of Medicine, Baltimore, MD 21201
| |
Collapse
|
32
|
Fox DK, Ebert SM, Bongers KS, Dyle MC, Bullard SA, Dierdorff JM, Kunkel SD, Adams CM. p53 and ATF4 mediate distinct and additive pathways to skeletal muscle atrophy during limb immobilization. Am J Physiol Endocrinol Metab 2014; 307:E245-61. [PMID: 24895282 PMCID: PMC4121573 DOI: 10.1152/ajpendo.00010.2014] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Immobilization causes skeletal muscle atrophy via complex signaling pathways that are not well understood. To better understand these pathways, we investigated the roles of p53 and ATF4, two transcription factors that mediate adaptations to a variety of cellular stresses. Using mouse models, we demonstrate that 3 days of muscle immobilization induces muscle atrophy and increases expression of p53 and ATF4. Furthermore, muscle fibers lacking p53 or ATF4 are partially resistant to immobilization-induced muscle atrophy, and forced expression of p53 or ATF4 induces muscle fiber atrophy in the absence of immobilization. Importantly, however, p53 and ATF4 do not require each other to promote atrophy, and coexpression of p53 and ATF4 induces more atrophy than either transcription factor alone. Moreover, muscle fibers lacking both p53 and ATF4 are more resistant to immobilization-induced atrophy than fibers lacking only p53 or ATF4. Interestingly, the independent and additive nature of the p53 and ATF4 pathways allows for combinatorial control of at least one downstream effector, p21. Using genome-wide mRNA expression arrays, we identified p21 mRNA as a skeletal muscle transcript that is highly induced in immobilized muscle via the combined actions of p53 and ATF4. Additionally, in mouse muscle, p21 induces atrophy in a manner that does not require immobilization, p53 or ATF4, and p21 is required for atrophy induced by immobilization, p53, and ATF4. Collectively, these results identify p53 and ATF4 as essential and complementary mediators of immobilization-induced muscle atrophy and discover p21 as a critical downstream effector of the p53 and ATF4 pathways.
Collapse
Affiliation(s)
- Daniel K Fox
- Departments of Internal Medicine and Molecular Physiology and Biophysics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa; and
| | - Scott M Ebert
- Departments of Internal Medicine and Molecular Physiology and Biophysics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa; and
| | - Kale S Bongers
- Departments of Internal Medicine and Molecular Physiology and Biophysics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa; and
| | - Michael C Dyle
- Departments of Internal Medicine and Molecular Physiology and Biophysics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa; and
| | - Steven A Bullard
- Departments of Internal Medicine and Molecular Physiology and Biophysics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa; and Iowa City Veterans Affairs Medical Center, Iowa City, Iowa
| | - Jason M Dierdorff
- Departments of Internal Medicine and Molecular Physiology and Biophysics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa; and
| | - Steven D Kunkel
- Departments of Internal Medicine and Molecular Physiology and Biophysics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa; and
| | - Christopher M Adams
- Departments of Internal Medicine and Molecular Physiology and Biophysics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa; and Iowa City Veterans Affairs Medical Center, Iowa City, Iowa
| |
Collapse
|
33
|
Xiao L, Wang JY. RNA-binding proteins and microRNAs in gastrointestinal epithelial homeostasis and diseases. Curr Opin Pharmacol 2014; 19:46-53. [PMID: 25063919 DOI: 10.1016/j.coph.2014.07.006] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 07/08/2014] [Accepted: 07/09/2014] [Indexed: 10/25/2022]
Abstract
The epithelium of gastrointestinal (GI) mucosa is a rapidly self-renewing tissue in the body, and its homeostasis is preserved through strict regulation of cell proliferation and apoptosis. Epithelial cells originate from a small number of pluripotent stem cells, which divide to either renew themselves or become committed crypt cells. RNA-binding proteins (RBPs) and microRNAs (miRNAs) regulate gene expression at the posttranscriptional level and are recently shown to modulate GI mucosal growth and repair after injury. Here we highlight the roles of RBPs HuR, CUG-binding protein 1, AU-binding factor 1, and several GI epithelial-specific miRNAs in gut mucosal homeostasis and diseases and also further analyze the mechanisms through which RBPs and miRNAs modulate the stability and translation of target mRNAs.
Collapse
Affiliation(s)
- Lan Xiao
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, USA; Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201, USA
| | - Jian-Ying Wang
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, USA; Department of Pathology, University of Maryland School of Medicine, USA; Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201, USA.
| |
Collapse
|
34
|
Cammas A, Sanchez BJ, Lian XJ, Dormoy-Raclet V, van der Giessen K, López de Silanes I, Ma J, Wilusz C, Richardson J, Gorospe M, Millevoi S, Giovarelli M, Gherzi R, Di Marco S, Gallouzi IE. Destabilization of nucleophosmin mRNA by the HuR/KSRP complex is required for muscle fibre formation. Nat Commun 2014; 5:4190. [PMID: 24969639 PMCID: PMC4074165 DOI: 10.1038/ncomms5190] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 05/21/2014] [Indexed: 01/03/2023] Open
Abstract
HuR promotes myogenesis by stabilizing the MyoD, myogenin and p21 mRNAs during the fusion of muscle cells to form myotubes. Here we show that HuR, via a novel mRNA destabilizing activity, promotes the early steps of myogenesis by reducing the expression of the cell cycle promoter nucleophosmin (NPM). Depletion of HuR stabilizes the NPM mRNA, increases NPM protein levels and inhibits myogenesis, while its overexpression elicits the opposite effects. NPM mRNA destabilization involves the association of HuR with the decay factor KSRP as well as the ribonuclease PARN and the exosome. The C terminus of HuR mediates the formation of the HuR-KSRP complex and is sufficient for maintaining a low level of the NPM mRNA as well as promoting the commitment of muscle cells to myogenesis. We therefore propose a model whereby the downregulation of the NPM mRNA, mediated by HuR, KSRP and its associated ribonucleases, is required for proper myogenesis.
Collapse
Affiliation(s)
- Anne Cammas
- 1] Department of Biochemistry, Goodman Cancer Center, McGill University, McIntyre Building Room 915B, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada H3G 1Y6 [2] INSERM, UMR 1037, Centre de Recherche en Cancérologie de Toulouse, 31432 Toulouse, France
| | - Brenda Janice Sanchez
- Department of Biochemistry, Goodman Cancer Center, McGill University, McIntyre Building Room 915B, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada H3G 1Y6
| | - Xian Jin Lian
- Department of Biochemistry, Goodman Cancer Center, McGill University, McIntyre Building Room 915B, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada H3G 1Y6
| | - Virginie Dormoy-Raclet
- Department of Biochemistry, Goodman Cancer Center, McGill University, McIntyre Building Room 915B, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada H3G 1Y6
| | - Kate van der Giessen
- Department of Biochemistry, Goodman Cancer Center, McGill University, McIntyre Building Room 915B, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada H3G 1Y6
| | - Isabel López de Silanes
- Spanish National Cancer Research Centre (CNIO) Telomeres and Telomerase Group, Molecular Oncology Program, C/ Melchor Fernández Almagro, 3, 28029 Madrid, Spain
| | - Jennifer Ma
- Department of Biochemistry, Goodman Cancer Center, McGill University, McIntyre Building Room 915B, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada H3G 1Y6
| | - Carol Wilusz
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado 80523-1682, USA
| | - John Richardson
- Department of Neurology and Neurosurgery, McGill University, 3801 University Street, Montreal, Quebec, Canada H3A2B4
| | - Myriam Gorospe
- National Institute on Aging, National Institutes of Health, Biomedical Research Center, Room 06C226, 251 Bayview Boulevard, Suite 100, Baltimore, Maryland 21224-6825, USA
| | - Stefania Millevoi
- INSERM, UMR 1037, Centre de Recherche en Cancérologie de Toulouse, 31432 Toulouse, France
| | - Matteo Giovarelli
- Istituto Nazionale Ricerca sul Cancro (IST), Laboratory of Gene Expression Regulation, c/o CBA Building A3, Room 30, Largo R. Benzi, 10, 16132 Genova, Italy
| | - Roberto Gherzi
- Istituto Nazionale Ricerca sul Cancro (IST), Laboratory of Gene Expression Regulation, c/o CBA Building A3, Room 30, Largo R. Benzi, 10, 16132 Genova, Italy
| | - Sergio Di Marco
- Department of Biochemistry, Goodman Cancer Center, McGill University, McIntyre Building Room 915B, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada H3G 1Y6
| | - Imed-Eddine Gallouzi
- Department of Biochemistry, Goodman Cancer Center, McGill University, McIntyre Building Room 915B, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada H3G 1Y6
| |
Collapse
|
35
|
Stabilization of p53 Is Involved in Quercetin-Induced Cell Cycle Arrest and Apoptosis in HepG2 Cells. Biosci Biotechnol Biochem 2014; 72:797-804. [DOI: 10.1271/bbb.70680] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
36
|
González-Feliciano JA, Hernández-Pérez M, Estrella LA, Colón-López DD, López A, Martínez M, Maurás-Rivera KR, Lasalde C, Martínez D, Araujo-Pérez F, González CI. The role of HuR in the post-transcriptional regulation of interleukin-3 in T cells. PLoS One 2014; 9:e92457. [PMID: 24658545 PMCID: PMC3962401 DOI: 10.1371/journal.pone.0092457] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Accepted: 02/21/2014] [Indexed: 02/05/2023] Open
Abstract
Human Interleukin-3 (IL-3) is a lymphokine member of a class of transiently expressed mRNAs harboring Adenosine/Uridine-Rich Elements (ARE) in their 3' untranslated regions (3'-UTRs). The regulatory effects of AREs are often mediated by specific ARE-binding proteins (ARE-BPs). In this report, we show that the human IL-3 3'-UTR plays a post-transcriptional regulation role in two human transformed cell lines. More specifically, we demonstrate that the hIL-3 3'-UTR represses the translation of a luciferase reporter both in HeLa and Jurkat T-cells. These results also revealed that the hIL-3 3'-UTR-mediated translational repression is exerted by an 83 nt region comprised mainly by AREs and some non-ARE sequences. Moreover, electrophoretic mobility shift assays (EMSAs) and UV-crosslinking analysis show that this hIL-3 ARE-rich region recruits five specific protein complexes, including the ARE-BPs HuR and TIA-1. HuR binding to this ARE-rich region appears to be spatially modulated during T-cell activation. Together, these results suggest that HuR recognizes the ARE-rich region and plays a role in the IL-3 3'-UTR-mediated post-transcriptional control in T-cells.
Collapse
Affiliation(s)
- José A. González-Feliciano
- University of Puerto Rico-Río Piedras, Department of Biology, College of Natural Sciences, San Juan, Puerto Rico
| | - Marimar Hernández-Pérez
- Department of Biochemistry, University of Puerto Rico-Medical Sciences, San Juan, Puerto Rico
| | - Luis A. Estrella
- University of Puerto Rico-Río Piedras, Department of Biology, College of Natural Sciences, San Juan, Puerto Rico
| | - Daisy D. Colón-López
- University of Puerto Rico-Río Piedras, Department of Biology, College of Natural Sciences, San Juan, Puerto Rico
| | - Armando López
- University of Puerto Rico-Río Piedras, Department of Biology, College of Natural Sciences, San Juan, Puerto Rico
| | - Marina Martínez
- Department of Biochemistry, University of Puerto Rico-Medical Sciences, San Juan, Puerto Rico
| | - Kirla R. Maurás-Rivera
- University of Puerto Rico-Río Piedras, Department of Biology, College of Natural Sciences, San Juan, Puerto Rico
| | - Clarivel Lasalde
- University of Puerto Rico-Río Piedras, Department of Biology, College of Natural Sciences, San Juan, Puerto Rico
| | - Daviana Martínez
- University of Puerto Rico-Río Piedras, Department of Biology, College of Natural Sciences, San Juan, Puerto Rico
| | - Félix Araujo-Pérez
- University of Puerto Rico-Río Piedras, Department of Biology, College of Natural Sciences, San Juan, Puerto Rico
| | - Carlos I. González
- University of Puerto Rico-Río Piedras, Department of Biology, College of Natural Sciences, San Juan, Puerto Rico
- Department of Biochemistry, University of Puerto Rico-Medical Sciences, San Juan, Puerto Rico
- Molecular Sciences Research Building, San Juan, Puerto Rico
| |
Collapse
|
37
|
Yang H, Rao JN, Wang JY. Posttranscriptional Regulation of Intestinal Epithelial Tight Junction Barrier by RNA-binding Proteins and microRNAs. Tissue Barriers 2014; 2:e28320. [PMID: 24843843 PMCID: PMC4022605 DOI: 10.4161/tisb.28320] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 02/16/2014] [Accepted: 02/21/2014] [Indexed: 12/19/2022] Open
Abstract
Intestinal epithelial tight junctions (TJs) are a specialized structure that determines the cell polarity and prevents the diffusion of toxins, allergens, and pathogens from the lumen into the tissue. TJs are highly dynamic and its constituent protein complexes undergo continuously remodeling and turnover under tight regulation by numerous extracellular and intracellular factors. RNA-binding proteins (RBPs) and microRNAs (miRNAs) regulate gene expression at the posttranscriptional level and are involved in many aspects of cellular physiology. An increasing body of evidence indicates that RBPs including HuR and CUG-binding protein 1 and miRNAs such as miR-192 modulate the stability and translation of mRNAs encoding TJ proteins and play an important role in the control of intestinal epithelial TJ barrier function. In this mini-review article, we highlight the changes in TJ expression and intestinal epithelial TJ barrier function after activation or inactivation of RBPs and miRNAs and further analyze in some detail the mechanisms through which the stability and translation of TJ mRNAs are regulated by RBPs and miRNAs.
Collapse
Affiliation(s)
- Hong Yang
- Cell Biology Group; Department of Surgery; University of Maryland School of Medicine; Baltimore, MD USA ; Baltimore Veterans Affairs Medical Center; Baltimore, MD USA
| | - Jaladanki N Rao
- Cell Biology Group; Department of Surgery; University of Maryland School of Medicine; Baltimore, MD USA ; Baltimore Veterans Affairs Medical Center; Baltimore, MD USA
| | - Jian-Ying Wang
- Cell Biology Group; Department of Surgery; University of Maryland School of Medicine; Baltimore, MD USA ; Department of Pathology; University of Maryland School of Medicine; Baltimore, MD USA ; Baltimore Veterans Affairs Medical Center; Baltimore, MD USA
| |
Collapse
|
38
|
Haque S, Yan XJ, Rosen L, McCormick S, Chiorazzi N, Mongini PKA. Effects of prostaglandin E2 on p53 mRNA transcription and p53 mutagenesis during T-cell-independent human B-cell clonal expansion. FASEB J 2013; 28:627-43. [PMID: 24145719 DOI: 10.1096/fj.13-237792] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Within T-cell-dependent germinal centers, p53 gene transcription is repressed by Bcl-6 and is thus less vulnerable to mutation. Malignant lymphomas within inflamed extranodal sites exhibit a relatively high incidence of p53 mutations. The latter might originate from normal B-cell clones manifesting activation-induced cytosine deaminase (AID) and up-regulated p53 following T-cell-independent (TI) stimulation. We here examine p53 gene transcription in such TI clones, with a focus on modulatory effects of prostaglandin E2 (PGE2), and evaluate progeny for p53 mutations. Resting IgM(+)IgD(+)CD27(-) B cells from human tonsils were labeled with CFSE and stimulated in vitro with complement-coated antigen surrogate, IL-4, and BAFF ± exogenous PGE2 (50 nM) or an analog specific for the EP2 PGE2 receptor. We use flow cytometry to measure p53 and AID protein within variably divided blasts, qRT-PCR of p53 mRNA from cultures with or without actinomycin D to monitor mRNA transcription/stability, and single-cell p53 RT-PCR/sequencing to assess progeny for p53 mutations. We report that EP2 signaling triggers increased p53 gene transcriptional activity in AID(+) cycling blasts (P<0.01). Progeny exhibit p53 mutations at a frequency (8.5 × 10(-4)) greater than the baseline error rate (<0.8 × 10(-4)). We conclude that, devoid of the repressive influences of Bcl-6, dividing B lymphoblasts in inflamed tissues should display heightened p53 transcription and increased risk of p53 mutagenesis.
Collapse
Affiliation(s)
- Shabirul Haque
- 1Laboratory of B-Cell Biology, Karches Center for CLL Research and Center for Autoimmunity and Musculoskeletal Diseases, Feinstein Institute for Medical Research, 350 Community Dr., Manhasset, NY 11030, USA.
| | | | | | | | | | | |
Collapse
|
39
|
Poly (C)-binding protein 1 regulates p63 expression through mRNA stability. PLoS One 2013; 8:e71724. [PMID: 23940783 PMCID: PMC3737132 DOI: 10.1371/journal.pone.0071724] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Accepted: 07/09/2013] [Indexed: 11/19/2022] Open
Abstract
p63, a transcription factor and p53 family protein, plays a crucial role in tumor suppression and development of various epithelial tissues. While p63 expression is controlled mostly by post-translational modifications, recent studies indicate that transcriptional and posttranscriptional regulations are essential for proper p63 expression. Here, we investigated the regulation of p63 expression by poly (C)-binding protein 1 (PCBP1, also known as hnRNP-E1 and αCP1). We found that knockdown of PCBP1 decreases the level of p63 transcript and protein. We also found that PCBP1 regulates the stability of p63 mRNA via binding to p63 3’UTR. Additionally, we found that a CU-rich element (CUE) in p63 3′UTR is bound by and responsive to PCBP1. Together, we conclude that PCBP1 regulates p63 expression via mRNA stability.
Collapse
|
40
|
Spermidine promotes adipogenesis of 3T3-L1 cells by preventing interaction of ANP32 with HuR and PP2A. Biochem J 2013; 453:467-74. [DOI: 10.1042/bj20130263] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We have shown previously that the polyamine spermidine is indispensable for differentiation of 3T3-L1 preadipocytes. In the present study, we examined the mechanism of spermidine function by using the polyamine biosynthesis inhibitor α-difluoromethylornithine in combination with the metabolically stable polyamine analogues γ-methylspermidine or (R,R)-α,ω-bismethylspermine. At the early phase of differentiation, spermidine-depleted 3T3-L1 cells showed decreased translation of the transcription factor C/EBPβ (CCAAT/enhancer-binding protein β), decreased PP2A (protein phosphatase 2A) activity and increased cytoplasmic localization of the RNA-binding protein HuR (human antigen R). The amount of HuR bound to C/EBPβ mRNA was reduced, whereas the amount of bound CUGBP2, an inhibitor of C/EBPβ translation, was increased. ANP32 (acidic nuclear phosphoprotein 32) proteins, which are known PP2A inhibitors and HuR ligands, bound more PP2A and HuR in spermidine-depleted than in control cells, whereas immunodepletion of ANP32 proteins from the lysate of spermidine-depleted cells restored PP2A activity. Taken together, our data shows that spermidine promotes C/EBPβ translation in differentiating 3T3-L1 cells, and that this process is controlled by the interaction of ANP32 with HuR and PP2A.
Collapse
|
41
|
Li Y, Yu J, DU D, Fu S, Chen Y, Yu F, Gao P. Involvement of post-transcriptional regulation of FOXO1 by HuR in 5-FU-induced apoptosis in breast cancer cells. Oncol Lett 2013; 6:156-160. [PMID: 23946796 PMCID: PMC3742653 DOI: 10.3892/ol.2013.1352] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2012] [Accepted: 09/04/2012] [Indexed: 12/28/2022] Open
Abstract
The post-transcriptional control of specific mRNAs is a widespread mechanism of gene regulation, which contributes to numerous biological processes in a number of cell types. The Forkhead box O (FoxO) transcription factor FOXO1 is an important tumor suppressor involved in apoptosis, the cell cycle, DNA damage repair and oxidative stress. Bioinformatic prediction identified that the 3' untranslated region (UTR) of FOXO1 is enriched with binding motifs for the human ELAV/Hu protein (HuR), indicating that FOXO1 is a potential target of HuR. Luciferase reporter assays demonstrate that HuR specifically regulates FOXO1 expression through AU-rich elements (AREs) within the FOXO1 3' UTR. Immunoprecipitation studies confirmed that HuR associates with FOXO1 mRNA in MDA-MB-231 breast cancer cells and that HuR upregulates FOXO1 mRNA levels through increased mRNA stability. Using a HuR loss- and gain-of-function approach, we revealed that FOXO1 expression was correspondingly decreased or increased in MDA-MB-231 cells. Functional assays demonstrated that HuR and FOXO1 expression levels were markedly enhanced upon 5-fluorouracil (5-FU) stimulation in MDA-MB-231 cells. Knockdown of HuR apparently abrogated 5-FU-induced apoptosis detected by caspase-3 activities. Furthermore, in HuR knockdown cells, additional overexpression of FOXO1 moderately recovered 5-FU-induced apoptosis, which verified that HuR-modulated apoptosis upon 5-FU treatment was partially mediated by its post-transcriptional regulation of FOXO1. Therefore, modulating FOXO1 expression has been suggested to lead to the development of new therapeutic treatments for certain types of cancer.
Collapse
Affiliation(s)
- Yunbo Li
- Norman Bethune College of Medicine, Jilin University, Changchun, Jilin 130041
| | | | | | | | | | | | | |
Collapse
|
42
|
Wang J, Guo Y, Chu H, Guan Y, Bi J, Wang B. Multiple functions of the RNA-binding protein HuR in cancer progression, treatment responses and prognosis. Int J Mol Sci 2013; 14:10015-41. [PMID: 23665903 PMCID: PMC3676826 DOI: 10.3390/ijms140510015] [Citation(s) in RCA: 202] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 04/22/2013] [Accepted: 04/25/2013] [Indexed: 12/16/2022] Open
Abstract
The human embryonic lethal abnormal vision-like protein, HuR, is a member of the Hu family of RNA-binding proteins. Over the past decade, this ubiquitously expressed protein has been extensively investigated in cancer research because it is involved in the regulation of mRNA stability and translation in many cell types. HuR activity and function is associated with its subcellular distribution, transcriptional regulation, translational and post-translational modifications. HuR regulation of target mRNAs is based on the interaction between the three specific domains of HuR protein and one or several U- or AU-rich elements (AREs) in the untranslated region of target mRNAs. A number of cancer-related transcripts containing AREs, including mRNAs for proto-oncogenes, cytokines, growth factors, and invasion factors, have been characterized as HuR targets. It has been proposed that HuR has a central tumorigenic activity by enabling multiple cancer phenotypes. In this review, we comprehensively survey the existing evidence with regard to the diverse functions of HuR in caner development and progression. The current data also suggest that HuR might be a novel and promising therapeutic target and a marker for treatment response and prognostic evaluation.
Collapse
Affiliation(s)
- Jun Wang
- Department of Oncology, General Hospital, Jinan Command of the People’s Liberation Army, Jinan 250031, China; E-Mails: (H.C.); (Y.G.); (J.B.); (B.W.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +86-531-5166-5336; Fax: +86-531-5166-6649
| | - Yan Guo
- Department of Outpatient, Military Command of Shandong Province, Jinan 250013, China; E-Mail:
| | - Huili Chu
- Department of Oncology, General Hospital, Jinan Command of the People’s Liberation Army, Jinan 250031, China; E-Mails: (H.C.); (Y.G.); (J.B.); (B.W.)
| | - Yaping Guan
- Department of Oncology, General Hospital, Jinan Command of the People’s Liberation Army, Jinan 250031, China; E-Mails: (H.C.); (Y.G.); (J.B.); (B.W.)
| | - Jingwang Bi
- Department of Oncology, General Hospital, Jinan Command of the People’s Liberation Army, Jinan 250031, China; E-Mails: (H.C.); (Y.G.); (J.B.); (B.W.)
| | - Baocheng Wang
- Department of Oncology, General Hospital, Jinan Command of the People’s Liberation Army, Jinan 250031, China; E-Mails: (H.C.); (Y.G.); (J.B.); (B.W.)
| |
Collapse
|
43
|
Jiang P, Smith AD, Li R, Rao JN, Liu L, Donahue JM, Wang JY, Turner DJ. Sphingosine kinase 1 overexpression stimulates intestinal epithelial cell proliferation through increased c-Myc translation. Am J Physiol Cell Physiol 2013; 304:C1187-97. [PMID: 23576579 DOI: 10.1152/ajpcell.00271.2012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Sphingosine-1-phosphate (S1P), through mechanisms that are not completely understood, is shown to modulate cellular proliferation, which is critically important for maintaining the integrity of intestinal epithelium. Here, we show that increased S1P promotes proliferation in intestinal epithelial cells. We found that overexpression of sphingosine kinase 1 (SphK1), the rate-limiting enzyme for S1P synthesis, significantly increased cell proliferation and that this occurred through enhanced expression of c-Myc. Further, we found that the increased pattern of expression of c-Myc occurred predominantly due to its increased translation. The overexpressed SphK1 led to increased checkpoint kinase 2 and enhanced HuR phosphorylation which allowed for increased translation of c-Myc mRNA through HuR binding at the 3'-untranslated regions. Our findings demonstrate that S1P modulates intestinal cell proliferation and provides new insights as to the mechanistic actions of SphK1 and S1P in maintaining intestinal epithelial homeostasis.
Collapse
Affiliation(s)
- Ping Jiang
- Baltimore Veterans Affairs Medical Center, Baltimore, MD 21201, USA
| | | | | | | | | | | | | | | |
Collapse
|
44
|
Positive and negative feedback loops in the p53 and mRNA 3' processing pathways. Proc Natl Acad Sci U S A 2013; 110:3351-6. [PMID: 23401530 DOI: 10.1073/pnas.1212533110] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Although the p53 network has been intensively studied, genetic analyses long hinted at the existence of components that remained elusive. Recent studies have shown regulation of p53 at the mRNA level mediated via both the 5' and the 3' untranslated regions and affecting the stability and translation efficiency of the p53 mRNA. Here, we provide evidence of a feedback loop between p53 and the poly(A)-specific ribonuclease (PARN), in which PARN deadenylase keeps p53 levels low in nonstress conditions by destabilizing p53 mRNA, and the UV-induced increase in p53 activates PARN deadenylase, regulating gene expression during DNA damage response in a transactivation-independent manner. This model is innovative because it provides insights into p53 function and the mechanisms behind the regulation of mRNA 3' end processing in different cellular conditions.
Collapse
|
45
|
Damgaard CK, Lykke-Andersen J. Regulation of ARE-mRNA Stability by Cellular Signaling: Implications for Human Cancer. Cancer Treat Res 2013; 158:153-80. [PMID: 24222358 DOI: 10.1007/978-3-642-31659-3_7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
During recent years, it has become clear that regulation of mRNA stability is an important event in the control of gene expression. The stability of a large class of mammalian mRNAs is regulated by AU-rich elements (AREs) located in the mRNA 3' UTRs. mRNAs with AREs are inherently labile but as a response to different cellular cues they can become either stabilized, allowing expression of a given gene, or further destabilized to silence their expression. These tightly regulated mRNAs include many that encode growth factors, proto-oncogenes, cytokines, and cell cycle regulators. Failure to properly regulate their stability can therefore lead to uncontrolled expression of factors associated with cell proliferation and has been implicated in several human cancers. A number of transfactors that recognize AREs and regulate the translation and degradation of ARE-mRNAs have been identified. These transfactors are regulated by signal transduction pathways, which are often misregulated in cancers. This chapter focuses on the function of ARE-binding proteins with an emphasis on their regulation by signaling pathways and the implications for human cancer.
Collapse
|
46
|
Zhao T, Goh KJ, Ng HH, Vardy LA. A role for polyamine regulators in ESC self-renewal. Cell Cycle 2012; 11:4517-23. [PMID: 23165208 DOI: 10.4161/cc.22772] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Embryonic stem cells (ESCs) depend on extensive regulatory networks to coordinate their self-renewal and differentiation. The polyamine pathway regulator AMD1 was recently implicated in ESC self-renewal and directed differentiation of ESCs to neural precursor cells (NPCs). The polyamines spermine and spermidine are essential for a wide range of biological processes, and their levels are tightly regulated. Here, we review the polyamine pathway and discuss how it can impact polyamine levels, cellular methylation and hypusinated EIF5A levels. We discuss how it could feed into regulation of ESC self-renewal and directed differentiation. We show that in addition to AMD1, a second rate-limiting enzyme in the polyamine pathway, ODC1, can also promote ESC self-renewal, and that both Amd1 and Odc1 can partially substitute for Myc during cellular reprogramming. We propose that both Amd1 and Odc1 are essential regulators of ESCs and function to ensure high polyamine levels to promote ESC self-renewal.
Collapse
|
47
|
Yu TX, Rao JN, Zou T, Liu L, Xiao L, Ouyang M, Cao S, Gorospe M, Wang JY. Competitive binding of CUGBP1 and HuR to occludin mRNA controls its translation and modulates epithelial barrier function. Mol Biol Cell 2012; 24:85-99. [PMID: 23155001 PMCID: PMC3541967 DOI: 10.1091/mbc.e12-07-0531] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The present study shows that RNA-binding proteins CUGBP1 and HuR jointly regulate the translation of occludin and play a crucial role in the maintenance of tight junction integrity. RNA-binding proteins CUG-binding protein 1 (CUGBP1) and HuR are highly expressed in epithelial tissues and modulate the stability and translation of target mRNAs. Here we present evidence that CUGBP1 and HuR jointly regulate the translation of occludin and play a crucial role in the maintenance of tight junction (TJ) integrity in the intestinal epithelial cell monolayer. CUGBP1 and HuR competed for association with the same occludin 3′-untranslated region element and regulated occludin translation competitively and in opposite directions. CUGBP1 overexpression decreased HuR binding to occludin mRNA, repressed occludin translation, and compromised the TJ barrier function, whereas HuR overexpression inhibited CUGBP1 association with occludin mRNA and promoted occludin translation, thereby enhancing the barrier integrity. Repression of occludin translation by CUGBP1 was due to the colocalization of CUGBP1 and tagged occludin RNA in processing bodies (P-bodies), and this colocalization was prevented by HuR overexpression. These findings indicate that CUGBP1 represses occludin translation by increasing occludin mRNA recruitment to P-bodies, whereas HuR promotes occludin translation by blocking occludin mRNA translocation to P-bodies via the displacement of CUGBP1.
Collapse
Affiliation(s)
- Ting-Xi Yu
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Chu PC, Chuang HC, Kulp SK, Chen CS. The mRNA-stabilizing factor HuR protein is targeted by β-TrCP protein for degradation in response to glycolysis inhibition. J Biol Chem 2012; 287:43639-50. [PMID: 23115237 DOI: 10.1074/jbc.m112.393678] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The mRNA-stabilizing protein HuR acts a stress response protein whose function and/or protein stability are modulated by diverse stress stimuli through posttranslational modifications. Here, we report a novel mechanism by which metabolic stress facilitates proteasomal degradation of HuR in cancer cells. In response to the glucose transporter inhibitor CG-5, HuR translocates to the cytoplasm, where it is targeted by the ubiquitin E3 ligase β-TrCP1 for degradation. The cytoplasmic localization of HuR is facilitated by PKCα-mediated phosphorylation at Ser-318 as the Ser-318 → alanine substitution abolishes the ability of the resulting HuR to bind PKCα and to undergo nuclear export. The mechanistic link between β-TrCP1 and HuR degradation was supported by the ability of ectopically expressed β-TrCP1 to mimic CG-5 to promote HuR degradation and by the protective effect of dominant negative inhibition of β-TrCP1 on HuR ubiquitination and degradation. Substrate targeting of HuR by β-TrCP1 was further verified by coimmunoprecipitation and in vitro GST pull-down assays and by the identification of a β-TrCP1 recognition site. Although HuR does not contain a DSG destruction motif, we obtained evidence that β-TrCP1 recognizes an unconventional motif, (296)EEAMAIAS(304), in the RNA recognition motif 3. Furthermore, mutational analysis indicates that IKKα-dependent phosphorylation at Ser-304 is crucial to the binding of HuR to β-TrCP1. Mechanistically, this HuR degradation pathway differs from that reported for heat shock and hypoxia, which underlies the complexity in the regulation of HuR turnover under different stress stimuli. The ability of glycolysis inhibitors to target the expression of oncogenic proteins through HuR degradation might foster novel strategies for cancer therapy.
Collapse
Affiliation(s)
- Po-Chen Chu
- Division of Medicinal Chemistry, College of Pharmacy and Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43221, USA
| | | | | | | |
Collapse
|
49
|
The mRNA-bound proteome and its global occupancy profile on protein-coding transcripts. Mol Cell 2012; 46:674-90. [PMID: 22681889 DOI: 10.1016/j.molcel.2012.05.021] [Citation(s) in RCA: 884] [Impact Index Per Article: 73.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 05/14/2012] [Accepted: 05/17/2012] [Indexed: 01/17/2023]
Abstract
Protein-RNA interactions are fundamental to core biological processes, such as mRNA splicing, localization, degradation, and translation. We developed a photoreactive nucleotide-enhanced UV crosslinking and oligo(dT) purification approach to identify the mRNA-bound proteome using quantitative proteomics and to display the protein occupancy on mRNA transcripts by next-generation sequencing. Application to a human embryonic kidney cell line identified close to 800 proteins. To our knowledge, nearly one-third were not previously annotated as RNA binding, and about 15% were not predictable by computational methods to interact with RNA. Protein occupancy profiling provides a transcriptome-wide catalog of potential cis-regulatory regions on mammalian mRNAs and showed that large stretches in 3' UTRs can be contacted by the mRNA-bound proteome, with numerous putative binding sites in regions harboring disease-associated nucleotide polymorphisms. Our observations indicate the presence of a large number of mRNA binders with diverse molecular functions participating in combinatorial posttranscriptional gene-expression networks.
Collapse
|
50
|
Rao JN, Rathor N, Zhuang R, Zou T, Liu L, Xiao L, Turner DJ, Wang JY. Polyamines regulate intestinal epithelial restitution through TRPC1-mediated Ca²+ signaling by differentially modulating STIM1 and STIM2. Am J Physiol Cell Physiol 2012; 303:C308-17. [PMID: 22592407 PMCID: PMC3423028 DOI: 10.1152/ajpcell.00120.2012] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Accepted: 05/14/2012] [Indexed: 11/22/2022]
Abstract
Early epithelial restitution occurs as a consequence of intestinal epithelial cell (IEC) migration after wounding, and its defective regulation is implicated in various critical pathological conditions. Polyamines stimulate intestinal epithelial restitution, but their exact mechanism remains unclear. Canonical transient receptor potential-1 (TRPC1)-mediated Ca(2+) signaling is crucial for stimulation of IEC migration after wounding, and induced translocation of stromal interaction molecule 1 (STIM1) to the plasma membrane activates TRPC1-mediated Ca(2+) influx and thus enhanced restitution. Here, we show that polyamines regulate intestinal epithelial restitution through TRPC1-mediated Ca(2+) signaling by altering the ratio of STIM1 to STIM2. Increasing cellular polyamines by ectopic overexpression of the ornithine decarboxylase (ODC) gene stimulated STIM1 but inhibited STIM2 expression, whereas depletion of cellular polyamines by inhibiting ODC activity decreased STIM1 but increased STIM2 levels. Induced STIM1/TRPC1 association by increasing polyamines enhanced Ca(2+) influx and stimulated epithelial restitution, while decreased formation of the STIM1/TRPC1 complex by polyamine depletion decreased Ca(2+) influx and repressed cell migration. Induced STIM1/STIM2 heteromers by polyamine depletion or STIM2 overexpression suppressed STIM1 membrane translocation and inhibited Ca(2+) influx and epithelial restitution. These results indicate that polyamines differentially modulate cellular STIM1 and STIM2 levels in IECs, in turn controlling TRPC1-mediated Ca(2+) signaling and influencing cell migration after wounding.
Collapse
Affiliation(s)
- Jaladanki N Rao
- Cell Biology Group, Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | | | | | | | | | | | | | | |
Collapse
|