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Guo HD, Wu JH, Wang HJ, Tan YZ. Delivery of Stem Cells and BMP-2 With Functionalized Self-Assembling Peptide Enhances Regeneration of Infarcted Myocardium. Stem Cell Rev Rep 2024; 20:1540-1554. [PMID: 38656478 DOI: 10.1007/s12015-024-10721-7] [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] [Accepted: 04/04/2024] [Indexed: 04/26/2024]
Abstract
Stem cell transplantation is a promising therapeutic strategy for myocardial infarction (MI). However, engraftment, survival and differentiation of the transplanted stem cells in ischemic and inflammatory microenvironment are poor. We designed a novel self-assembly peptide (SAP) by modifying the peptide RADA16 with cell-adhesive motif and BMP-2 (bone morphogenetic protein-2)-binding motif. Effects of the functionalized SAP on adhesion, survival and differentiation of c-kit+ MSCs (mesenchymal stem cells) were examined. Myocardial regeneration, neovascularization and cardiac function were assessed after transplantation of the SAP loading c-kit+ MSCs and BMP-2 in rat MI models. The SAP could spontaneously assemble into well-ordered nanofibrous scaffolds. The cells adhered to the SAP scaffolds and spread well. The SAP protected the cells in the condition of hypoxia and serum deprivation. Following degradation of the SAP, BMP-2 was released sustainedly and induced c-kit+ MSCs to differentiate into cardiomyocytes. At four weeks after transplantation of the SAP loading c-kit+ MSCs and BMP-2, myocardial regeneration and angiogenesis were enhanced, and cardiac function was improved significantly. The cardiomyocytes differentiated from the engrafted c-kit+ MSCs were increased markedly. The differentiated cells connected with recipient cardiomyocytes to form gap junctions. Collagen volume was decreased dramatically. These results suggest that the functionalized SAP promotes engraftment, survival and differentiation of stem cells effectively. Local sustained release of BMP-2 with SAP is a viable strategy to enhance differentiation of the engrafted stem cells and repair of the infarcted myocardium.
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Affiliation(s)
- Hai-Dong Guo
- Department of Anatomy, Histology and Embryology, Shanghai Medical School of Fudan University, 138 Yixueyuan Road, Shanghai, 200032, People's Republic of China
| | - Jin-Hong Wu
- Department of Anatomy, Histology and Embryology, Shanghai Medical School of Fudan University, 138 Yixueyuan Road, Shanghai, 200032, People's Republic of China
- Department of Anesthesiology, Eye & ENT Hospital of Fudan University, Shanghai, 200031, People's Republic of China
| | - Hai-Jie Wang
- Department of Anatomy, Histology and Embryology, Shanghai Medical School of Fudan University, 138 Yixueyuan Road, Shanghai, 200032, People's Republic of China.
- Rehabilitation Therapy Department, School of Health Sciences, West Yunnan University of Applied Sciences, Dali, Yunnan Province, 671000, People's Republic of China.
| | - Yu-Zhen Tan
- Department of Anatomy, Histology and Embryology, Shanghai Medical School of Fudan University, 138 Yixueyuan Road, Shanghai, 200032, People's Republic of China.
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Liu B, Ou WC, Fang L, Tian CW, Xiong Y. Myocyte Enhancer Factor 2A Plays a Central Role in the Regulatory Networks of Cellular Physiopathology. Aging Dis 2022; 14:331-349. [PMID: 37008050 PMCID: PMC10017154 DOI: 10.14336/ad.2022.0825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 08/25/2022] [Indexed: 11/18/2022] Open
Abstract
Cell regulatory networks are the determinants of cellular homeostasis. Any alteration to these networks results in the disturbance of cellular homeostasis and induces cells towards different fates. Myocyte enhancer factor 2A (MEF2A) is one of four members of the MEF2 family of transcription factors (MEF2A-D). MEF2A is highly expressed in all tissues and is involved in many cell regulatory networks including growth, differentiation, survival and death. It is also necessary for heart development, myogenesis, neuronal development and differentiation. In addition, many other important functions of MEF2A have been reported. Recent studies have shown that MEF2A can regulate different, and sometimes even mutually exclusive cellular events. How MEF2A regulates opposing cellular life processes is an interesting topic and worthy of further exploration. Here, we reviewed almost all MEF2A research papers published in English and summarized them into three main sections: 1) the association of genetic variants in MEF2A with cardiovascular disease, 2) the physiopathological functions of MEF2A, and 3) the regulation of MEF2A activity and its regulatory targets. In summary, multiple regulatory patterns for MEF2A activity and a variety of co-factors cause its transcriptional activity to switch to different target genes, thereby regulating opposing cell life processes. The association of MEF2A with numerous signaling molecules establishes a central role for MEF2A in the regulatory network of cellular physiopathology.
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Affiliation(s)
- Benrong Liu
- Department of Cardiology, Guangzhou Institute of Cardiovascular Disease, Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China.
- Correspondence should be addressed to: Dr. Benrong Liu, the Second Affiliated Hospital, Guangzhou Medical University, Guangdong, China. E-mail: ; or Yujuan Xiong, Panyu Hospital of Chinese Medicine, Guangzhou University of Chinese Medicine, Guangdong, China. .
| | - Wen-Chao Ou
- Department of Cardiology, Guangzhou Institute of Cardiovascular Disease, Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China.
| | - Lei Fang
- Department of Cardiology, Guangzhou Institute of Cardiovascular Disease, Guangdong Key Laboratory of Vascular Diseases, State Key Laboratory of Respiratory Disease, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China.
| | - Chao-Wei Tian
- General Practice, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China.
| | - Yujuan Xiong
- Department of Laboratory Medicine, Panyu Hospital of Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, China.
- Correspondence should be addressed to: Dr. Benrong Liu, the Second Affiliated Hospital, Guangzhou Medical University, Guangdong, China. E-mail: ; or Yujuan Xiong, Panyu Hospital of Chinese Medicine, Guangzhou University of Chinese Medicine, Guangdong, China. .
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Hart CG, Karimi-Abdolrezaee S. Bone morphogenetic proteins: New insights into their roles and mechanisms in CNS development, pathology and repair. Exp Neurol 2020; 334:113455. [PMID: 32877654 DOI: 10.1016/j.expneurol.2020.113455] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/18/2020] [Accepted: 08/26/2020] [Indexed: 02/06/2023]
Abstract
Bone morphogenetic proteins (BMPs) are a highly conserved and diverse family of proteins that play essential roles in various stages of development including the formation and patterning of the central nervous system (CNS). Bioavailability and function of BMPs are regulated by input from a plethora of transcription factors and signaling pathways. Intriguingly, recent literature has uncovered novel roles for BMPs in regulating homeostatic and pathological responses in the adult CNS. Basal levels of BMP ligands and receptors are widely expressed in the adult brain and spinal cord with differential expression patterns across CNS regions, cell types and subcellular locations. Recent evidence indicates that several BMP isoforms are transiently or chronically upregulated in the aged or pathological CNS. Genetic knockout and pharmacological studies have elucidated that BMPs regulate several aspects of CNS injury and repair including cell survival and differentiation, reactive astrogliosis and glial scar formation, axon regeneration, and myelin preservation and repair. Several BMP isoforms can be upregulated in the injured or diseased CNS simultaneously yet exert complementary or opposing effects on the endogenous cell responses after injury. Emerging studies also show that dysregulation of BMPs is associated with various CNS pathologies. Interestingly, modulation of BMPs can lead to beneficial or detrimental effects on CNS injury and repair mechanisms in a ligand, temporally or spatially specific manner, which reflect the complexity of BMP signaling. Given the significance of BMPs in neurodevelopment, a better understanding of their role in the context of injury may provide new therapeutic targets for the pathologic CNS. This review will provide a timely overview on the foundation and recent advancements in knowledge regarding the role and mechanisms of BMP signaling in the developing and adult CNS, and their implications in pathological responses and repair processes after injury or diseases.
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Affiliation(s)
- Christopher G Hart
- Department of Physiology and Pathophysiology, Regenerative Medicine Program, Spinal Cord Research Centre, Children's Hospital Research Institute of Manitoba, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Soheila Karimi-Abdolrezaee
- Department of Physiology and Pathophysiology, Regenerative Medicine Program, Spinal Cord Research Centre, Children's Hospital Research Institute of Manitoba, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada.
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Yang T, Wei BH, Hao SL, Wei YL, Yang WX. Bone morphogenetic protein 2 (BMP2) mediates spermatogenesis in Chinese mitten crab Eriocheir sinensis by regulating kinesin motor KIFC1 expression. Gene 2020; 754:144848. [PMID: 32522697 DOI: 10.1016/j.gene.2020.144848] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2020] [Revised: 05/18/2020] [Accepted: 06/02/2020] [Indexed: 12/15/2022]
Abstract
The TGF-beta superfamily is widely involved in cell events such as cell division and differentiation, while bone morphogenetic proteins (BMPs) belong to one of the subgroups. Their functions in crustacean spermatogenesis are still unknown. In this study, we first identified the bone morphogenetic protein 2 (bmp2) from Eriocheir sinensis (E. sinensis) testis. The es-BMP2 shows high expression in E. sinensis testis. We found that es-BMP2 is expressed in spermatids. The successfully knockdown of es-BMP2 through in vivo RNAi are used for functional analysis. Compared with the control group, the proportion of abnormal nuclear cup morphology in mature spermatozoa increased significantly after es-bmp2 RNAi, suggesting that es-BMP2 plays an important role in mature sperm morphogenesis. Immunofluorescence results confirm this finding. In order to study the specific mechanism of es-BMP2 involved in spermiogenesis, we tested kinesin-14 KIFC1, which functions in the nucleus formation of spermatozoa in E. sinensis. The results showed that knockdown of es-BMP2 caused a significant decrease of es-KIFC1 expression. We further performed es-bmp2 knockdown in vitro in primary cultured testis cells. es-KIFC1 expression was significantly reduced after es-bmp2 RNAi. The above results indicate that es-BMP2 participates in maintaining the spermiogenesis of E. sinensis by regulating es-KIFC1 expression.
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Affiliation(s)
- Tong Yang
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Bang-Hong Wei
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Shuang-Li Hao
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Ya-Lan Wei
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Wan-Xi Yang
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
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Wang YL, Zhang G, Wang HJ, Tan YZ, Wang XY. Preinduction with bone morphogenetic protein-2 enhances cardiomyogenic differentiation of c-kit + mesenchymal stem cells and repair of infarcted myocardium. Int J Cardiol 2019; 265:173-180. [PMID: 29885685 DOI: 10.1016/j.ijcard.2018.01.134] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 01/27/2018] [Accepted: 01/31/2018] [Indexed: 10/14/2022]
Abstract
BACKGROUND Preclinical and clinical trails show that c-kit+ cardiac stem cells can differentiate towards cardiovascular cells and improve cardiac function after myocardial infarction (MI). However, survival and differentiation of the engrafted stem cells within ischemic and inflammatory microenvironment are poor. METHODS c-Kit+ cells were isolated from mesenchymal stem cells (MSCs) of rat bone marrow. Reliability of preinduction with bone morphogenetic protein-2 (BMP-2) in promotion of survival and differentiation of c-kit+ MSCs was assessed in vitro and after transplantation. RESULTS c-Kit+ MSCs have a potential to differentiate towards cardiomyocytes. BMP-2 promotes proliferation, migration and paracrine of the cells, and protects the cells to survive in the hypoxic condition. After induction with 10 ng/mL BMP-2 for 24 h, the cells can differentiate into cardiomyocytes at four weeks. The electrophysiological characteristics of the differentiated cells are same as adult ventricular cardiomyocytes. In rat MI models, cardiac function was improved, the size of scar tissue was reduced, and regeneration of the myocardium and microvessels was enhanced significantly at four weeks after transplantation of BMP-2-preinduced cells. The survived cells and cardiomyocytes differentiated from the engrafted cells were increased greatly. CONCLUSION The results suggest that transient treatment with BMP-2 can induce c-kit+ MSCs to differentiate into functional cardiomyocytes. Preinduction with BMP-2 enhances survival and differentiation of the cells. BMP-2-primed cells promote repair of the infarcted myocardium and improvement of cardiac function. Transplantation of BMP-2-preinduced c-kit+ MSCs is a feasible strategy for MI therapy.
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Affiliation(s)
- Yong-Li Wang
- Department of Anatomy, Histology and Embryology, Shanghai Medical School of Fudan University, Shanghai 200032, China
| | - Guitao Zhang
- Department of Anatomy, Histology and Embryology, Shanghai Medical School of Fudan University, Shanghai 200032, China; Department of Anatomy, Histology and Embryology, Capital Medical University, Beijing, China
| | - Hai-Jie Wang
- Department of Anatomy, Histology and Embryology, Shanghai Medical School of Fudan University, Shanghai 200032, China.
| | - Yu-Zhen Tan
- Department of Anatomy, Histology and Embryology, Shanghai Medical School of Fudan University, Shanghai 200032, China.
| | - Xin-Yan Wang
- Department of Anatomy, Histology and Embryology, Shanghai Medical School of Fudan University, Shanghai 200032, China
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Akt2 causes TGFβ-induced deptor downregulation facilitating mTOR to drive podocyte hypertrophy and matrix protein expression. PLoS One 2018; 13:e0207285. [PMID: 30444896 PMCID: PMC6239304 DOI: 10.1371/journal.pone.0207285] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 10/29/2018] [Indexed: 02/06/2023] Open
Abstract
TGFβ promotes podocyte hypertrophy and expression of matrix proteins in fibrotic kidney diseases such as diabetic nephropathy. Both mTORC1 and mTORC2 are hyperactive in response to TGFβ in various renal diseases. Deptor is a component of mTOR complexes and a constitutive inhibitor of their activities. We identified that deptor downregulation by TGFβ maintains hyperactive mTOR in podocytes. To unravel the mechanism, we found that TGFβ -initiated noncanonical signaling controls deptor inhibition. Pharmacological inhibitor of PI 3 kinase, Ly 294002 and pan Akt kinase inhibitor MK 2206 prevented the TGFβ induced downregulation of deptor, resulting in suppression of both mTORC1 and mTORC2 activities. However, specific isoform of Akt involved in this process is not known. We identified Akt2 as predominant isoform expressed in kidney cortex, glomeruli and podocytes. TGFβ time-dependently increased the activating phosphorylation of Akt2. Expression of dominant negative PI 3 kinase and its signaling inhibitor PTEN blocked Akt2 phosphorylation by TGFβ. Inhibition of Akt2 using a phospho-deficient mutant that inactivates its kinase activity, as well as siRNA against the kinase markedly diminished TGFβ -mediated deptor suppression, its association with mTOR and activation of mTORC1 and mTORC2. Importantly, inhibition of Akt2 blocked TGFβ -induced podocyte hypertrophy and expression of the matrix protein fibronectin. This inhibition was reversed by the downregulation of deptor. Interestingly, we detected increased phosphorylation of Akt2 concomitant with TGFβ expression in the kidneys of diabetic rats. Thus, our data identify previously unrecognized Akt2 kinase as a driver of TGFβ induced deptor downregulation and sustained mTORC1 and mTORC2 activation. Furthermore, we provide the first evidence that deptor downstream of Akt2 contributes to podocyte hypertrophy and matrix protein expression found in glomerulosclerosis in different renal diseases.
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Aquino-Martínez R, Angelo AP, Pujol FV. Calcium-containing scaffolds induce bone regeneration by regulating mesenchymal stem cell differentiation and migration. Stem Cell Res Ther 2017; 8:265. [PMID: 29145866 PMCID: PMC5689169 DOI: 10.1186/s13287-017-0713-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 10/18/2017] [Accepted: 10/26/2017] [Indexed: 11/17/2022] Open
Abstract
Background Osteoinduction and subsequent bone formation rely on efficient mesenchymal stem cell (MSC) recruitment. It is also known that migration is induced by gradients of growth factors and cytokines. Degradation of Ca2+-containing biomaterials mimics the bone remodeling compartment producing a localized calcium-rich osteoinductive microenvironment. The aim of our study was to determine the effect of calcium sulfate (CaSO4) on MSC migration. In addition, to evaluate the influence of CaSO4 on MSC differentiation and the potential molecular mechanisms involved. Methods A circular calvarial bone defect (5 mm diameter) was created in the parietal bone of 35 Balb-C mice. We prepared and implanted a cell-free agarose/gelatin scaffold alone or in combination with different CaSO4 concentrations into the bone defects. After 7 weeks, we determined the new bone regenerated by micro-CT and histological analysis. In vitro, we evaluated the CaSO4 effects on MSC migration by both wound healing and agarose spot assays. Osteoblastic gene expression after BMP-2 and CaSO4 treatment was also evaluated by qPCR. Results CaSO4 increased MSC migration and bone formation in a concentration-dependent manner. Micro-CT analysis showed that the addition of CaSO4 significantly enhanced bone regeneration compared to the scaffold alone. The histological evaluation confirmed an increased number of endogenous cells recruited into the cell-free CaSO4-containing scaffolds. Furthermore, MSC migration in vitro and active AKT levels were attenuated when CaSO4 and BMP-2 were in combination. Addition of LY294002 and Wortmannin abrogated the CaSO4 effects on MSC migration. Conclusions Specific CaSO4 concentrations induce bone regeneration of calvarial defects in part by acting on the host’s undifferentiated MSCs and promoting their migration. Progenitor cell recruitment is followed by a gradual increment in osteoblast gene expression. Moreover, CaSO4 regulates BMP-2-induced MSC migration by differentially activating the PI3K/AKT pathway. Altogether, these results suggest that CaSO4 scaffolds could have potential applications for bone regeneration. Electronic supplementary material The online version of this article (doi:10.1186/s13287-017-0713-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Rubén Aquino-Martínez
- Departament de Ciències Fisiològiques, Universitat de Barcelona, IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain.,Division of Endocrinology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Alcira P Angelo
- Departament de Ciències Fisiològiques, Universitat de Barcelona, IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Francesc Ventura Pujol
- Departament de Ciències Fisiològiques, Universitat de Barcelona, IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain.
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Desjardins CA, Naya FJ. The Function of the MEF2 Family of Transcription Factors in Cardiac Development, Cardiogenomics, and Direct Reprogramming. J Cardiovasc Dev Dis 2016; 3. [PMID: 27630998 PMCID: PMC5019174 DOI: 10.3390/jcdd3030026] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Proper formation of the mammalian heart requires precise spatiotemporal transcriptional regulation of gene programs in cardiomyocytes. Sophisticated regulatory networks have evolved to not only integrate the activities of distinct transcription factors to control tissue-specific gene programs but also, in many instances, to incorporate multiple members within these transcription factor families to ensure accuracy and specificity in the system. Unsurprisingly, perturbations in this elaborate transcriptional circuitry can lead to severe cardiac abnormalities. Myocyte enhancer factor–2 (MEF2) transcription factor belongs to the evolutionarily conserved cardiac gene regulatory network. Given its central role in muscle gene regulation and its evolutionary conservation, MEF2 is considered one of only a few core cardiac transcription factors. In addition to its firmly established role as a differentiation factor, MEF2 regulates wide variety of, sometimes antagonistic, cellular processes such as cell survival and death. Vertebrate genomes encode multiple MEF2 family members thereby expanding the transcriptional potential of this core transcription factor in the heart. This review highlights the requirement of the MEF2 family and their orthologs in cardiac development in diverse animal model systems. Furthermore, we describe the recently characterized role of MEF2 in direct reprogramming and genome-wide cardiomyocyte gene regulation. A thorough understanding of the regulatory functions of the MEF2 family in cardiac development and cardiogenomics is required in order to develop effective therapeutic strategies to repair the diseased heart.
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Rogers MB, Shah TA, Shaikh NN. Turning Bone Morphogenetic Protein 2 (BMP2) on and off in Mesenchymal Cells. J Cell Biochem 2016; 116:2127-38. [PMID: 25776852 DOI: 10.1002/jcb.25164] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 03/10/2015] [Indexed: 01/26/2023]
Abstract
The concentration, location, and timing of bone morphogenetic protein 2 (BMP2, HGNC:1069, GeneID: 650) gene expression must be precisely regulated. Abnormal BMP2 levels cause congenital anomalies and diseases involving the mesenchymal cells that differentiate into muscle, fat, cartilage, and bone. The molecules and conditions that influence BMP2 synthesis are diverse. Understandably, complex mechanisms control Bmp2 gene expression. This review includes a compilation of agents and conditions that can induce Bmp2. The currently known trans-regulatory factors and cis-regulatory elements that modulate Bmp2 expression are summarized and discussed. Bone morphogenetic protein 2 (BMP2, HGNC:1069, GeneID: 650) is a classical morphogen; a molecule that acts at a distance and whose concentration influences cell behavior. In mesenchymal cells, the concentration of BMP2 influences myogenesis, adipogenesis, chondrogenesis, and osteogenesis. Because the amount, timing, and location of BMP2 synthesis influence the allocation of cells to muscle, fat, cartilage, and bone, the mechanisms that regulate the Bmp2 gene are crucial. Key early mesodermal events that require precise Bmp2 regulation include heart specification and morphogenesis. Originally named for its osteoinductive properties, healing fractures requires BMP2. The human Bmp2 gene also has been linked to osteoporosis and osteoarthritis. In addition, all forms of pathological calcification in the vasculature and in cardiac valves involve the pro-osteogenic BMP2. The diverse tissues, mechanisms, and diseases influenced by BMP2 are too numerous to list here (see OMIM: 112261). However, in all BMP2-influenced pathologies, changes in the behavior and differentiation of pluripotent mesenchymal cells are a recurring theme. Consequently, much effort has been devoted to identifying the molecules and conditions that influence BMP2 synthesis and the complex mechanisms that control Bmp2 gene expression. This review begins with an overview of the Bmp2 gene's chromosomal neighborhood and then summarizes and evaluates known regulatory mechanisms and inducers.
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Affiliation(s)
- Melissa B Rogers
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Newark, NJ
| | - Tapan A Shah
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Newark, NJ
| | - Nadia N Shaikh
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Newark, NJ
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Chen L, Wei H, Tan J, Chen H, Liu Z, Chen Y. Bone Morphogenetic Protein 9 and 13 Induce C3H10T1/2 Cell Differentiation to Cardiomyocyte-Like Cells In Vitro. Cell Transplant 2014; 24:909-20. [PMID: 24380493 DOI: 10.3727/096368913x676907] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The present study aimed to evaluate the effect of bone morphogenetic protein 9 (BMP9) and BMP13 on cardiac differentiation of C3H10T1/2 cells in vitro and to characterize the differentiated cells on their ultrastructure and transmembrane electrophysiological features. C3H10T1/2 cells were transfected with the vectors for BMP9 or BMP13 and differentiated into cardiomyocytes in vitro for up to 28 days. The expression of cardiac-specific genes Gata4 and Mef2c and proteins troponin T (cTnT) and connexin 43 (Cx43) was significantly increased in the cells transfected with BMP9 or BMP13 after differentiation over the controls as evaluated using quantitative RT-PCR, Western blotting, and immunofluorescence staining. Transmission electron microscopy and Masson trichrome staining showed that the specific myocardial leap dish and myofilament-like structure were present in the cells overexpressing BMP9 or BMP13, not in the control cells. Whole-cell patch-clamping study demonstrated the presence of delayed rectifier potassium current, inward rectifier potassium current, and T-type calcium current in the cells overexpressing BMP9 or BMP13. Sodium current was detected in a small number of cells overexpressing BMP9, not in the BMP13-transfected cells or the control cells. The expression of Mef2c gene and Cx43 and cTnT proteins was also significantly higher in the cells overexpressing BMP9 than those overexpressing BMP13. Our data indicate that BMP9 and BMP13 (BMP9 might be more effective) promoted the differentiation of C3H10T1/2 cells into cardiomyocyte-like cells with cellular ultrastructures and ion channel currents similar to mature cardiomyocytes in vitro.
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Affiliation(s)
- Lu Chen
- Department of Cardiology, Children's Hospital of Chongqing Medical University, Chongqing, China
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Hou J, Lü AL, Liu BW, Xing YJ, Da J, Hou ZL, Ai SY. Combination of BMP-2 and 5-AZA is advantageous in rat bone marrow-derived mesenchymal stem cells differentiation into cardiomyocytes. Cell Biol Int 2013; 37:1291-9. [PMID: 23881855 DOI: 10.1002/cbin.10161] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2013] [Accepted: 07/08/2013] [Indexed: 12/31/2022]
Abstract
Bone morphogenetic protein-2 (BMP-2) has a crucial role in the development of cardiogenesis, and is used in inducing bone marrow mesenchymal stem cells (BMMSCs) to differentiate into cardiomyocytes. We have examined a combination of BMP-2 and 5-azacytidine (5-AZA) in inducing these differentiation effects. BMMSCs were collected and purified from bone marrow of 4-week-old Sprague-Dawley (SD) rats by density-gradient centrifugation and differential attachment. The fourth passage subculture of BMMSCs, selected by cytometry for purity and identification, was divided into four groups: a control group, BMP-2 treated, 5-AZA treated, and a combination of BMP-2 and 5-AZA treatment. Expression of cardiac Troponin I (cTnI) and Connexin 43 (CX-43) in BMMSCs after induction were detected by immunofluorescence and Western blot. Flow cytometry analysis was used for differentiation rates and apoptosis of induced BMMSCs, through the expression of cardiac Troponin T (cTnT) and Annexin V-FITC & PI kit, respectively. BMP-2 can ameliorate apoptosis of BMMSCs caused by 5-AZA and promote the differentiation of BMMSCs into cardiomyocyte-like cells. Thus a combination of BMP-2 and 5-AZA can significantly improve the cardiac differentiation with fewer cell damage effects, making it a safe and effective method of induction in vitro.
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Affiliation(s)
- Jing Hou
- Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, 710032, China
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Ghosh-Choudhury N, Mandal CC, Das F, Ganapathy S, Ahuja S, Ghosh Choudhury G. c-Abl-dependent molecular circuitry involving Smad5 and phosphatidylinositol 3-kinase regulates bone morphogenetic protein-2-induced osteogenesis. J Biol Chem 2013; 288:24503-17. [PMID: 23821550 DOI: 10.1074/jbc.m113.455733] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Skeletal remodeling consists of timely formation and resorption of bone by osteoblasts and osteoclasts in a quantitative manner. Patients with chronic myeloid leukemia receiving inhibitors of c-Abl tyrosine kinase often show reduced bone remodeling due to impaired osteoblast and osteoclast function. BMP-2 plays a significant role in bone generation and resorption by contributing to the formation of mature osteoblasts and osteoclasts. The effects of c-Abl on BMP-2-induced bone remodeling and the underlying mechanisms are not well studied. Using a pharmacological inhibitor and expression of a dominant negative mutant of c-Abl, we show an essential role of this tyrosine kinase in the development of bone nodules containing mature osteoblasts and formation of multinucleated osteoclasts in response to BMP-2. Calvarial osteoblasts prepared from c-Abl null mice showed the absolute requirement of this tyrosine kinase in maturation of osteoblasts and osteoclasts. Activation of phosphatidylinositol 3-kinase (PI 3-kinase)/Akt signaling by BMP-2 leads to osteoblast differentiation. Remarkably, inhibition of c-Abl significantly suppressed BMP-2-stimulated PI 3-kinase activity and its downstream Akt phosphorylation. Interestingly, c-Abl regulated BMP-2-induced osteoclastogenic CSF-1 expression. More importantly, we identified the requirements of c-Abl in BMP-2 autoregulation and the expressions of alkaline phosphatase and osterix that are necessary for osteoblast differentiation. c-Abl contributed to BMP receptor-specific Smad-dependent transcription of CSF-1, osterix, and BMP-2. Finally, c-Abl associates with BMP receptor IA and regulates phosphorylation of Smad in response to BMP-2. We propose that activation of c-Abl is an important step, which induces into two signaling pathways involving noncanonical PI 3-kinase and canonical Smads to integrate BMP-2-induced osteogenesis.
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Affiliation(s)
- Nandini Ghosh-Choudhury
- Veterans Affairs Research, South Texas Veterans Health Care System, San Antonio, Texas 78229, USA.
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Mandal CC, Drissi H, Choudhury GG, Ghosh-Choudhury N. Integration of phosphatidylinositol 3-kinase, Akt kinase, and Smad signaling pathway in BMP-2-induced osterix expression. Calcif Tissue Int 2010; 87:533-40. [PMID: 20872216 PMCID: PMC3055166 DOI: 10.1007/s00223-010-9419-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Accepted: 07/23/2010] [Indexed: 12/31/2022]
Abstract
Osterix (Osx), a BMP-2-regulated transcription factor, controls expression of genes essential for osteoblast differentiation. Using progressive deletion of the Osx promoter, we characterized a Smad binding element (SBE) between -552 and -839 bp from its transcription start site. Electrophoretic mobility shift assay and chromatin immunoprecipitation assay showed binding and in vivo recruitment of Smads 1 and 5 to the Osx SBE. Inactivation of PI 3-kinase by the pharmacologic inhibitor Ly294002 or by dominant negative (DN) enzyme significantly blocked BMP-2-induced Osx protein and mRNA expression and Osx transcription. Finally, both DN PI 3-kinase and DN Akt significantly attenuated Smad 5-dependent transcription of Osx, demonstrating the first evidence for a concerted action of PI 3-kinase/Akt signaling with BMP-specific Smads for expression of Osx.
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Affiliation(s)
- Chandi Charan Mandal
- Department of Pathology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Hicham Drissi
- Department of Orthopedic Surgery, New England Musculoskeletal Institute, University of Connecticut Health Center, Farmington, CT, USA
| | - Goutam Ghosh Choudhury
- Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA. Geriatric Research, Education and Clinical Center, South Texas Veterans Health Care System, San Antonio, TX, USA. VA Research, South Texas Veterans Health Care System, San Antonio, TX, USA
| | - Nandini Ghosh-Choudhury
- Department of Pathology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA. VA Research, South Texas Veterans Health Care System, San Antonio, TX, USA
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Song H, Song BW, Cha MJ, Choi IG, Hwang KC. Modification of mesenchymal stem cells for cardiac regeneration. Expert Opin Biol Ther 2010; 10:309-19. [PMID: 20132054 DOI: 10.1517/14712590903455997] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
IMPORTANCE OF THE FIELD Mesenchymal stem cells (MSCs) have the greatest potential for use in cell-based therapy of human heart diseases, especially in myocardial infarcts. The therapeutic potential of MSCs in myocardial repair is based on the ability of MSCs to directly differentiate into cardiac tissue and on the paracrine actions of factors released from MSCs. However, the major obstacle in the clinical application of MSC-based therapy is the poor viability of the transplanted cells due to harsh microenvironments like ischemia, inflammation and/or anoikis in the infarcted myocardium. Recently, various approaches have been implemented in an effort to improve the survival of implanted MSCs through ex vivo manipulation of MSCs. AREAS COVERED IN THIS REVIEW Major obstacles in MSC-based therapy are discussed, along with recent advances for enhancing therapeutic potential of engrafted MSCs from the past decade. WHAT THE READER WILL GAIN This review focuses primarily on ex vivo manipulation of MSCs before transplantation, which includes pretreatment, preconditioning and genetic modification of MSCs, and future directions. TAKE HOME MESSAGE Modification of MSCs before transplantation has developed into a promising option for enhancing the beneficial effects of MSC-based therapy for cardiac repair after myocardial infarction.
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Affiliation(s)
- Heesang Song
- Yonsei University College of Medicine, Cardiovascular Research Institute, 250 Seongsanno,Seodaemun-gu, Seoul, Republic of Korea
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15
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Mandal CC, Ghosh Choudhury G, Ghosh-Choudhury N. Phosphatidylinositol 3 kinase/Akt signal relay cooperates with smad in bone morphogenetic protein-2-induced colony stimulating factor-1 (CSF-1) expression and osteoclast differentiation. Endocrinology 2009; 150:4989-98. [PMID: 19819979 PMCID: PMC2775973 DOI: 10.1210/en.2009-0026] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Murine spleen cells produce mature osteoclasts when cocultured with osteoblastic cells. Colony-stimulating factor (CSF)-1 is the growth factor required for differentiating the monocyte-macrophage precursor cells into preosteoclasts. Bone morphogenic protein (BMP) signaling in osteoblasts regulates bone mass in mice, suggesting a role of BMP in osteoclastogenesis along with osteoblast activity. The intracellular signal transduction cross talk regulating the osteoblastic production of CSF-1 as a mechanism of BMP-induced osteoclastogenesis is described in this report. We have recently described the involvement of Smad 1/5 in BMP-2-induced CSF-1 expression and osteoclast formation. In this study, using the pharmacological inhibitors and the adenovirus (Ad) vectors expressing dominant-negative (DN) phosphatidylinositol 3 kinase (PI3K), the PI3K-signaling inhibitor, phosphatase and tensin homolog deleted in chromosome 10 (PTEN) or DN Akt kinase in the in vitro coculture assay, we show an essential role of the lipid kinase cascade in BMP-2-mediated multinucleated osteoclast formation and CSF-1 mRNA expression, transcription, and secretion. Inhibition of PI3K/Akt signaling blocked the binding of Smads 1/5 to the CSF-1 BMP-responsive element present in the CSF-1 promoter, resulting in attenuation of Smad-dependent CSF-1 transcription. Furthermore, PI3K inhibition and DN Akt prevented association of the transcriptional coactivator, CREB (cAMP response element binding protein) binding protein (CBP), with Smads 1/5. Together, these data for the first time demonstrate that PI3K-dependent Akt activation regulates BMP-2-induced CSF-1 expression and provides a mechanism for osteoblastic cell-assisted osteoclast differentiation.
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Affiliation(s)
- Chandi C Mandal
- Department of Pathology, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA
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Sui X, Li D, Qiu H, Gaussin V, Depre C. Activation of the Bone Morphogenetic Protein Receptor by H11Kinase/Hsp22 Promotes Cardiac Cell Growth and Survival. Circ Res 2009; 104:887-95. [DOI: 10.1161/circresaha.108.192328] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Xiangzhen Sui
- From the Cardiovascular Research Institute, Department of Cell Biology and Molecular Medicine, University of Medicine and Dentistry New Jersey, New Jersey Medical School, Newark
| | - Dan Li
- From the Cardiovascular Research Institute, Department of Cell Biology and Molecular Medicine, University of Medicine and Dentistry New Jersey, New Jersey Medical School, Newark
| | - Hongyu Qiu
- From the Cardiovascular Research Institute, Department of Cell Biology and Molecular Medicine, University of Medicine and Dentistry New Jersey, New Jersey Medical School, Newark
| | - Vinciane Gaussin
- From the Cardiovascular Research Institute, Department of Cell Biology and Molecular Medicine, University of Medicine and Dentistry New Jersey, New Jersey Medical School, Newark
| | - Christophe Depre
- From the Cardiovascular Research Institute, Department of Cell Biology and Molecular Medicine, University of Medicine and Dentistry New Jersey, New Jersey Medical School, Newark
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Dore JJ, DeWitt JC, Setty N, Donald MD, Joo E, Chesarone MA, Birren SJ. Multiple signaling pathways converge to regulate bone-morphogenetic-protein-dependent glial gene expression. Dev Neurosci 2009; 31:473-86. [PMID: 19325229 DOI: 10.1159/000210187] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2008] [Accepted: 01/12/2009] [Indexed: 12/22/2022] Open
Abstract
A fundamental problem in developmental neuroscience is understanding how extracellular cues link to complex intracellular signaling pathways to drive stage-specific developmental decisions. During the formation of the mammalian peripheral nervous system, bone morphogenetic proteins (BMPs) promote neuronal differentiation. BMPs also maintain the expression of early glial genes such as GFAP, while blocking the acquisition of a mature, myelinating Schwann cell phenotype. We investigated the BMP-activated signaling pathways that contribute to early glial gene expression to address the question of how specific signaling interactions contribute to cell fate decisions in neural crest lineages. Using a neural-crest-derived cell line that exhibits the characteristics of immature Schwann cells, we found that BMP2 promotes GFAP expression using Smad signaling as well as the phosphoinositide-3 kinase (PI3K) and mitogen-activated protein kinase1/2extracellular signal-regulated kinase- (MEK1/2/ERK) pathways. The GFAP promoter does not contain known Smad consensus sites, suggesting that Smads may act indirectly to promote GFAP expression. We provide evidence that this indirect effect may be mediated via induction of immediate early genes and the transcription factor Sp1 by demonstrating that these transcriptional regulators are induced by BMP2 and contribute to GFAP promoter activity. These findings demonstrate new roles for intracellular kinase pathways in mediating the effects of BMPs during the early stages of glial differentiation and suggest that differential contributions by signaling and transcriptional networks may contribute to the range of effects of BMPs on neuronal and glial development during the formation of the peripheral nervous system.
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Affiliation(s)
- Justin J Dore
- Department of Biology and Volen National Center for Complex Systems, Brandeis University, Waltham, Mass. 02454, USA
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Weber W, Luzi S, Karlsson M, Sanchez-Bustamante CD, Frey U, Hierlemann A, Fussenegger M. A synthetic mammalian electro-genetic transcription circuit. Nucleic Acids Res 2009; 37:e33. [PMID: 19190091 PMCID: PMC2651811 DOI: 10.1093/nar/gkp014] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Electric signal processing has evolved to manage rapid information transfer in neuronal networks and muscular contraction in multicellular organisms and controls the most sophisticated man-built devices. Using a synthetic biology approach to assemble electronic parts with genetic control units engineered into mammalian cells, we designed an electric power-adjustable transcription control circuit able to integrate the intensity of a direct current over time, to translate the amplitude or frequency of an alternating current into an adjustable genetic readout or to modulate the beating frequency of primary heart cells. Successful miniaturization of the electro-genetic devices may pave the way for the design of novel hybrid electro-genetic implants assembled from electronic and genetic parts.
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Affiliation(s)
- Wilfried Weber
- ETH Zurich, Department of Biosystems Science and Engineering, Mattenstrasse 26, CH-4058 Basel, Switzerland
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20
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Sanchez-Bustamante CD, Frey U, Kelm JM, Hierlemann A, Fussenegger M. Modulation of cardiomyocyte electrical properties using regulated bone morphogenetic protein-2 expression. Tissue Eng Part A 2009; 14:1969-88. [PMID: 18673087 DOI: 10.1089/ten.tea.2007.0302] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Because cardiomyocytes lose their ability to divide after birth, any subsequent cell loss or dysfunction results in pathologic cardiac rhythm initiation or impulse conduction. Strategies to restore and control the electrophysiological activity of the heart may, therefore, greatly affect the regeneration of cardiac tissue functionality. Using lentivirus-derived particles to regulate the bone morphogenetic protein-2 (BMP-2) gene expression in a pristinamycin- or gaseous acetaldehyde-inducible manner, we demonstrated the adjustment of cardiomyocyte electrophysiological characteristics. Complementary metal oxide semiconductor-based high-density microelectrode arrays (HD-MEAs) were used to monitor the electrophysiological activity of neonatal rat cardiomyocytes (NRCs) cultured as monolayers (NRCml) or as microtissues (NRCmt). NRCmt more closely resembled heart tissue physiology than did NRCml and could be conveniently monitored using HD-MEAs because of their ability to detect low-signal events and to sub-select the region of interest, namely, areas where the microtissues were placed. Cardiomyocyte-forming microtissues, transduced using lentiviral vectors encoding BMP-2, were capable of restoring myocardial microtissue electrical activity. We also engineered NRCmt to functionally couple within a cardiomyocyte monolayer, thus showing pacemaker-like activity upon local regulation of transgenic BMP-2 expression. The controlled expression of therapeutic transgenes represents a crucial advance for clinical interventions and gene-function analysis.
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21
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Ghosh-Choudhury T, Mandal CC, Woodruff K, St Clair P, Fernandes G, Choudhury GG, Ghosh-Choudhury N. Fish oil targets PTEN to regulate NFkappaB for downregulation of anti-apoptotic genes in breast tumor growth. Breast Cancer Res Treat 2008; 118:213-28. [PMID: 18953692 DOI: 10.1007/s10549-008-0227-7] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2008] [Accepted: 10/09/2008] [Indexed: 12/20/2022]
Abstract
The molecular mechanism for the beneficial effect of fish oil on breast tumor growth is largely undefined. Using the xenograft model in nude mice, we for the first time report that the fish oil diet significantly increased the level of PTEN protein in the breast tumors. In addition, the fish oil diet attenuated the PI 3 kinase and Akt kinase activity in the tumors leading to significant inhibition of NFkappaB activation. Fish oil diet also prevented the expression of anti-apoptotic proteins Bcl-2 and Bcl-XL in the breast tumors with concomitant increase in caspase 3 activity. To extend these findings we tested the functional effects of DHA and EPA, the two active omega-3 fatty acids of fish oil, on cultured MDA MB-231 cells. In agreement with our in vivo data, DHA and EPA treatment increased PTEN mRNA and protein expression and inhibited the phosphorylation of p65 subunit of NFkappaB in MDA MB-231 cells. Furthermore, DHA and EPA reduced expression of Bcl-2 and Bcl-XL. NFkappaB DNA binding activity and NFkappaB-dependent transcription of Bcl-2 and Bcl-XL genes were also prevented by DHA and EPA treatment. Finally, we showed that PTEN expression significantly inhibited NFkappaB-dependent transcription of Bcl-2 and Bcl-XL genes. Taken together, our data reveals a novel signaling pathway linking the fish oil diet to increased PTEN expression that attenuates the growth promoting signals and augments the apoptotic signals, resulting in breast tumor regression.
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Affiliation(s)
- Triparna Ghosh-Choudhury
- Department of Pathology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
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22
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Vasquez MM, Castro R, Seidner SR, Henson BM, Ashton DJ, Mustafa SB. Induction of serum- and glucocorticoid-induced kinase-1 (SGK1) by cAMP regulates increases in alpha-ENaC. J Cell Physiol 2008; 217:632-42. [PMID: 18615584 DOI: 10.1002/jcp.21534] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Alpha-ENaC expression and activity is regulated by a variety of hormones including beta-adrenergic agonists via the second messenger cAMP. We evaluated the early intermediate pathways involved in the up-regulation of SGK1 by DbcAMP and whether SGK1 is a prerequisite for induction of alpha-ENaC expression. Submandibular gland epithelial (SMG-C6) cells treated with DbcAMP (1 mM) induced both SGK1 mRNA and protein expression. DbcAMP-stimulated SGK1 mRNA expression was decreased by actinomycin D and mRNA and protein expressions were attenuated by PKA inhibitors (H-89 and KT5720). Inhibition of PI3-K with either LY294002 or dominant negative PI3-K reduced DbcAMP-stimulated SGK1 protein and mRNA levels, attenuated the phosphorylation of CREB (a cAMP-activated transcription factor) and decreased alpha-ENaC protein levels and Na(+) transport. In addition, the combination of PKA inhibitors with dominant negative PI3-K synergistically inhibited DbcAMP-induced Na(+) transport. Inhibition of SGK1 expression by siRNA decreased but did not obliterate DbcAMP-induced alpha-ENaC expression. Thus, in a cell line which endogenously exhibits minimal alpha-ENaC expression, induction of SGK1 by DbcAMP occurs via the PI3-K and PKA pathways. Increased alpha-ENaC levels and function are partly dependent upon the early induction of SGK1 expression.
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Affiliation(s)
- Margarita M Vasquez
- Department of Pediatrics/Division of Neonatology, University of Texas Health Science Center, San Antonio, Texas 78229, USA.
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23
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Nesselmann C, Ma N, Bieback K, Wagner W, Ho A, Konttinen YT, Zhang H, Hinescu ME, Steinhoff G. Mesenchymal stem cells and cardiac repair. J Cell Mol Med 2008; 12:1795-810. [PMID: 18684237 PMCID: PMC4506151 DOI: 10.1111/j.1582-4934.2008.00457.x] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2008] [Accepted: 08/01/2008] [Indexed: 12/20/2022] Open
Abstract
Accumulating clinical and experimental evidence indicates that mesenchymal stem cells (MSCs) are promising cell types in the treatment of cardiac dysfunction. They may trigger production of reparative growth factors, replace damaged cells and create an environment that favours endogenous cardiac repair. However, identifying mechanisms which regulate the role of MSCs in cardiac repair is still at work. To achieve the maximal clinical benefits, ex vivo manipulation can further enhance MSC therapeutic potential. This review focuses on the mechanism of MSCs in cardiac repair, with emphasis on ex vivo manipulation.
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Affiliation(s)
| | - Nan Ma
- Department of Cardiac Surgery, University of RostockGermany
| | - Karen Bieback
- Institute for Transfusion Medicine and Immunology, Medical Faculty Mannheim, University of Heidelberg, German Red Cross Blood Donor Service Baden-Württemberg – HessenGermany
| | | | - Anthony Ho
- Medizinische Klinik V, Heidelberg UniversityGermany
| | | | - Hao Zhang
- Cardiovascular Institute & Fuwai Hospital, Chinese Academy of Medical Sciences, P.R.China
| | - Mihail E Hinescu
- Department of Cellular and Molecular Medicine, ‘Carol Davila’ University of Medicine and PharmacyBucharest, Romania
- Victor Babes National Institute of PathologyBucharest, Romania
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Hahn JY, Cho HJ, Kang HJ, Kim TS, Kim MH, Chung JH, Bae JW, Oh BH, Park YB, Kim HS. Pre-treatment of mesenchymal stem cells with a combination of growth factors enhances gap junction formation, cytoprotective effect on cardiomyocytes, and therapeutic efficacy for myocardial infarction. J Am Coll Cardiol 2008; 51:933-43. [PMID: 18308163 DOI: 10.1016/j.jacc.2007.11.040] [Citation(s) in RCA: 246] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2007] [Revised: 10/26/2007] [Accepted: 11/27/2007] [Indexed: 11/25/2022]
Abstract
OBJECTIVES The goal of this study was to investigate the effect of pre-treatment of mesenchymal stem cells (MSCs) with growth factors (GFs) on cardiomyogenic differentiation, cytoprotective action on cardiomyocytes (CMCs), and their therapeutic efficacy in myocardial infarction. BACKGROUND Mechanisms of myocardial repair with MSC transplantation have not been fully elucidated, and therapeutic efficacy needs to be enhanced. METHODS The MSCs obtained from the bone marrow of Fisher344 rats were treated with fibroblast growth factor-2, insulin-like growth factor-1, and bone morphogenetic protein-2. The expression of cardiac specific markers and the cytoprotective effect of MSCs with its mechanism were evaluated. Efficacy of MSCs transplantation was studied in rat myocardial infarction model. RESULTS Treatment of MSCs with cocktails of GFs enhanced expression of cardiac transcription factors and survival. Induction of cardiac specific markers by coculture with CMCs and gap junctional communication with CMCs was more active in GF-treated MSCs than untreated MSCs. The GF-treated MSCs reduced apoptosis of neighboring CMCs in a hypoxic condition and enhanced the phosphorylated Akt and phosphorylated c-AMP response element binding protein expression of CMCs, which was markedly reduced by gap junction blockade. In a rat myocardial infarction model, transplantation of GF-treated MSCs resulted in smaller infarct size and better cardiac function than transplantation of untreated MSCs. Additionally, GF treatment enhanced gap junction formation of transplanted MSCs, which did not aggravate arrhythmia. CONCLUSIONS Pre-treatment of MSCs with GFs enhanced cytoprotective effects on neighboring CMCs through gap junction and improved the therapeutic efficacy of MSC transplantation for myocardial repair. "Priming of MSCs with GFs" before transplantation might improve the therapeutic efficacy of cell therapy.
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Affiliation(s)
- Joo-Yong Hahn
- National Research Laboratory for Cardiovascular Stem Cells, Seoul National University College of Medicine, Seoul, Republic of Korea
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Abstract
Bone morphogenetic protein (BMP) signals play key roles throughout embryology, from the earliest patterning events, via tissue specification, through organ development and again in germ cell differentiation. While both input and the transducer molecules are rather well studied, the final outcome of a BMP signal is basically unpredictable and differs enormously between previously studied cell types. As already suggested by their name, BMPs exhibit most of their (known) functions on stem cells and precursor cells, usually driving them into various types of differentiation or death. In this minireview, some prime examples of BMP effects on several very different stem-cell types are discussed.
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Affiliation(s)
- Toni U Wagner
- Physiological Chemistry I, University of Wuerzburg, Germany.
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26
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Ghosh-Choudhury N, Mandal CC, Choudhury GG. Statin-induced Ras activation integrates the phosphatidylinositol 3-kinase signal to Akt and MAPK for bone morphogenetic protein-2 expression in osteoblast differentiation. J Biol Chem 2006; 282:4983-4993. [PMID: 17179158 DOI: 10.1074/jbc.m606706200] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Lovastatin promotes osteoblast differentiation by increasing bone morphogenetic protein-2 (BMP-2) expression. We demonstrate that lovastatin stimulates tyrosine phosphorylation of the p85 regulatory subunit of phosphatidylinositol 3-kinase (PI3K), leading to an increase in its kinase activity in osteoblast cells. Inhibition of PI3K ameliorated expression of the osteogenic markers alkaline phosphatase, type I collagen, osteopontin, and BMP-2. Expression of dominant-negative PI3K and PTEN, an inhibitor of PI3K signaling, significantly attenuated lovastatin-induced transcription of BMP-2. Akt kinase was also activated in a PI3K-dependent manner. However, our data suggest involvement of an additional signaling pathway. Lovastatin-induced Erk1/2 activity contributed to BMP-2 transcription. Inhibition of PI3K abrogated Erk1/2 activity in response to lovastatin, indicating the presence of a signal relay between them. We provide, as a mechanism of this cross-talk, the first evidence that lovastatin stimulates rapid activation of Ras, which associates with and activates PI3K in the plasma membrane, which in turn regulates Akt and Erk1/2 to induce BMP-2 expression for osteoblast differentiation.
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Affiliation(s)
- Nandini Ghosh-Choudhury
- Departments of South Texas Veterans Health Care System, San Antonio, Texas 78229; Geriatric Research, Education, and Clinical Center, and the South Texas Veterans Health Care System, San Antonio, Texas 78229.
| | - Chandi Charan Mandal
- Departments of South Texas Veterans Health Care System, San Antonio, Texas 78229; Pathology and South Texas Veterans Health Care System, San Antonio, Texas 78229
| | - Goutam Ghosh Choudhury
- Geriatric Research, Education, and Clinical Center, and the South Texas Veterans Health Care System, San Antonio, Texas 78229; Medicine, The University of Texas Health Science Center at San Antonio, the South Texas Veterans Health Care System, San Antonio, Texas 78229; South Texas Veterans Health Care System, San Antonio, Texas 78229
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Kousteni S, Almeida M, Han L, Bellido T, Jilka RL, Manolagas SC. Induction of osteoblast differentiation by selective activation of kinase-mediated actions of the estrogen receptor. Mol Cell Biol 2006; 27:1516-30. [PMID: 17158928 PMCID: PMC1800724 DOI: 10.1128/mcb.01550-06] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Estrogens control gene transcription by cis or trans interactions of the estrogen receptor (ER) with target DNA or via the activation of cytoplasmic kinases. We report that selective activation of kinase-mediated actions of the ER with 4-estren-3alpha,17beta-diol (estren) or an estradiol-dendrimer conjugate, each a synthetic compound that stimulates kinase-mediated ER actions 1,000 to 10,000 times more potently than direct DNA interactions, induced osteoblastic differentiation in established cell lines of uncommitted osteoblast precursors and primary cultures of osteoblast progenitors by stimulating Wnt and BMP-2 signaling in a kinase-dependent manner. In sharp contrast, 17beta-estradiol (E(2)) suppressed BMP-2-induced osteoblast progenitor commitment and differentiation. Consistent with the in vitro findings, estren, but not E(2), stimulated Wnt/beta-catenin-mediated transcription in T-cell factor-lacZ transgenic mice. Moreover, E(2) stimulated BMP signaling in mice in which ERalpha lacks DNA binding activity and classical estrogen response element-mediated transcription (ERalpha(NERKI/-)) but not in wild-type controls. This evidence reveals for the first time the existence of a large signalosome in which inputs from the ER, kinases, bone morphogenetic proteins, and Wnt signaling converge to induce differentiation of osteoblast precursors. ER can either induce it or repress it, depending on whether the activating ligand (and presumably the resulting conformation of the receptor protein) precludes or accommodates ERE-mediated transcription.
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Affiliation(s)
- Stavroula Kousteni
- Division of Endocrinology and Metabolism, University of Arkansas for Medical Sciences, 4301 West Markham, Little Rock, AR 72205, USA
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28
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Ghosh-Choudhury N, Singha PK, Woodruff K, St Clair P, Bsoul S, Werner SL, Choudhury GG. Concerted action of Smad and CREB-binding protein regulates bone morphogenetic protein-2-stimulated osteoblastic colony-stimulating factor-1 expression. J Biol Chem 2006; 281:20160-70. [PMID: 16707491 DOI: 10.1074/jbc.m511071200] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Bone remodeling depends upon proper osteoblast and osteoclast function. Bone morphogenetic protein-2 (BMP-2) stimulates differentiation of osteoblasts from pluripotent precursors. Osteoclast formation depends on the concerted action of osteoblast-derived receptor activator of NF-kappaB ligand and colony-stimulating factor-1 (CSF-1). BMP-2 stimulates receptor activator of NF-kappaB ligand expression. However, the effect of BMP-2 on CSF-1 expression has not been studied. We investigated the role of BMP-2 in CSF-1 expression in osteogenic C2C12 cells. Incubation of C2C12 cells with BMP-2 supported osteoclastogenesis of spleen cells with a concomitant increase in expression of CSF-1 mRNA and protein. To determine the mechanism, we identified a BMP-responsive element between -627 bp and -509 bp in the CSF-1 promoter. DNase I footprint analysis revealed the presence of consensus Smad binding motif in this region. Electrophoretic mobility shift assay showed BMP-2-stimulated binding of proteins to this motif. Mutation of core sequence as well as its 5'- and 3'-flanking sequences abolished the DNA-protein interaction resulting in inhibition of CSF-1 transcription. Supershift analysis detects the presence of Smads 1, 5, and 4 and the transcriptional coactivator CREB-binding protein in the BMP-responsive element-protein complex. In addition, Smads 1 and 5 alone or in combination with Smad 4 increased CSF-1 transcription. Furthermore, CREB-binding protein markedly increased transcription of CSF-1. These data represent the first evidence that BMP-2 increases the osteoclastogenic CSF-1 expression by a transcriptional mechanism using the canonical Smad pathway and provide a mechanism for BMP-2-induced osteoclast differentiation.
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Affiliation(s)
- Nandini Ghosh-Choudhury
- Department of Pathology, University of Texas Health Science Center, San Antonio, TX 78229, USA.
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Fritz DT, Jiang S, Xu J, Rogers MB. A polymorphism in a conserved posttranscriptional regulatory motif alters bone morphogenetic protein 2 (BMP2) RNA:protein interactions. Mol Endocrinol 2006; 20:1574-86. [PMID: 16497730 DOI: 10.1210/me.2005-0469] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The bone morphogenetic protein (BMP)2 gene has been genetically linked to osteoporosis and osteoarthritis. We have shown that the 3'-untranslated regions (UTR) of BMP2 genes from mammals to fishes are extraordinarily conserved. This indicates that the BMP2 3'-UTR is under stringent selective pressure. We present evidence that the conserved region is a strong posttranscriptional regulator of BMP2 expression. Polymorphisms in cis-regulatory elements have been proven to influence susceptibility to a growing number of diseases. A common single nucleotide polymorphism (SNP) disrupts a putative posttranscriptional regulatory motif, an AU-rich element, within the BMP2 3'-UTR. The affinity of specific proteins for the rs15705 SNP sequence differs from their affinity for the normal human sequence. More importantly, the in vitro decay rate of RNAs with the SNP is higher than that of RNAs with the normal sequence. Such changes in mRNA:protein interactions may influence the posttranscriptional mechanisms that control BMP2 gene expression. The consequent alterations in BMP2 protein levels may influence the development or physiology of bone or other BMP2-influenced tissues.
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Affiliation(s)
- David T Fritz
- Biochemistry and Molecular Biology, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, Newark, New Jersey 07101-1709, USA
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Bettiol E, Clement S, Krause KH, Jaconi ME. Embryonic and adult stem cell-derived cardiomyocytes: lessons from in vitro models. Rev Physiol Biochem Pharmacol 2006; 157:1-30. [PMID: 17236648 DOI: 10.1007/112_0508] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
For years, research has focused on how to treat heart failure by sustaining the overloaded remaining cardiomyocytes. Recently, the concept of cell replacement therapy as a treatment of heart diseases has opened a new area of investigation. In vitro-generated cardiomyocytes could be injected into the heart to rescue the function of a damaged myocardium. Embryonic and/or adult stem cells could provide cardiac cells for this purpose. Knowledge of fundamental cardiac differentiation mechanisms unraveled by studies on animal models has been improved using in vitro models of cardiogenesis such as mouse embryonal carcinoma cells, mouse embryonic stem cells and, recently, human embryonic stem cells. On the other hand, studies suggesting the existence of cardiac stem cells and the potential of adult stem cells from bone marrow or skeletal muscle to differentiate toward unexpected phenotypes raise hope and questions about their potential use for cardiac cell therapy. In this review, we compare the specificities of embryonic vs adult stem cell populations regarding their cardiac differentiation potential, and we give an overview of what in vitro models have taught us about cardiogenesis.
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Affiliation(s)
- E Bettiol
- University of Geneva, Department of Pathology and Immunology, Faculty of Medicine, Switzerland
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Abstract
Bone morphogenetic proteins (BMPs) play important roles in cardiovascular development. However, how BMP-signaling pathways regulate cardiac gene expression is less clear. We have previously identified myocardin as a cardiac and smooth muscle-specific transcriptional cofactor for serum response factor (SRF). Myocardin potently activates target gene expression by tethering with SRF bound to SRF-responsive elements, the CArG box. Here, we show that Smad1, an effector of the BMP-signaling pathway, synergistically activates myocardin-dependent cardiac gene expression. Interestingly, the CArG box is necessary and sufficient to mediate such synergy, whereas no obvious Smad-binding element appears to be involved. Consistent with their functional interaction, we find that myocardin and Smad1 proteins interact directly. Furthermore, myocardin protein levels were dramatically increased by BMP-2 treatment in cardiomyocytes. These findings suggest myocardin participates in a BMP signaling-dependent cardiac gene transcriptional program.
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Affiliation(s)
- Thomas E Callis
- Department of Cell and Developmental Biology, Carolina Cardiovascular Biology Center, University of North Carolina, Chapel Hill, NC, USA
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Dore JJ, Crotty KL, Birren SJ. Inhibition of glial maturation by bone morphogenetic protein 2 in a neural crest-derived cell line. Dev Neurosci 2005; 27:37-48. [PMID: 15886483 DOI: 10.1159/000084531] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2004] [Accepted: 11/05/2004] [Indexed: 12/23/2022] Open
Abstract
Bone morphogenetic proteins (BMPs) regulate developmental decisions in many neural and nonneural lineages. BMPs influence both CNS neuronal and glial development and promote neuronal differentiation in neural crest derivatives. We investigated the actions of BMP2 on glial differentiation in the peripheral nervous system using NCM1 cells, a neural crest-derived cell line with the properties of peripheral glial precursor cells. BMP2 prevented the acquisition of a mature Schwann cell-like morphology, blocking the expression of mature genes and maintaining expression of several early glial markers. We provide evidence that BMP2 activates the GFAP promoter and define signaling pathways underlying this regulation. Our results demonstrate a novel role for BMPs as inhibitors of glial differentiation in the peripheral nervous system and suggest that BMPs may regulate the developmental timing of glial maturation.
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Affiliation(s)
- Justin J Dore
- Department of Biology, Volen Center for Complex Systems, Brandeis University Waltham, Waltham, MA 02454, USA
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Mechanical stretch is a highly selective regulator of gene expression in human bladder smooth muscle cells. Physiol Genomics 2004; 20:36-44. [PMID: 15467014 DOI: 10.1152/physiolgenomics.00181.2004] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Application of mechanical stimuli has been shown to alter gene expression in bladder smooth muscle cells (SMC). To date, only a limited number of "stretch-responsive" genes in this cell type have been reported. We employed oligonucleotide arrays to identify stretch-sensitive genes in primary culture human bladder SMC subjected to repetitive mechanical stimulation for 4 h. Differential gene expression between stretched and nonstretched cells was assessed using Significance Analysis of Microarrays (SAM). Expression of 20 out of 11,731 expressed genes ( approximately 0.17%) was altered >2-fold following stretch, with 19 genes induced and one gene (FGF-9) repressed. Using real-time RT-PCR, we tested independently the responsiveness of 15 genes to stretch and to platelet-derived growth factor-BB (PDGF-BB), another hypertrophic stimulus for bladder SMC. In response to both stimuli, expression of 13 genes increased, 1 gene (FGF-9) decreased, and 1 gene was unchanged. Six transcripts (HB-EGF, BMP-2, COX-2, LIF, PAR-2, and FGF-9) were evaluated using an ex vivo rat model of bladder distension. HB-EGF, BMP-2, COX-2, LIF, and PAR-2 increased with bladder stretch ex vivo, whereas FGF-9 decreased, consistent with expression changes observed in vitro. In silico analysis of microarray data using the FIRED algorithm identified c-jun, AP-1, ATF-2, and neurofibromin-1 (NF-1) as potential transcriptional mediators of stretch signals. Furthermore, the promoters of 9 of 13 stretch-responsive genes contained AP-1 binding sites. These observations identify stretch as a highly selective regulator of gene expression in bladder SMC. Moreover, they suggest that mechanical and growth factor signals converge on common transcriptional regulators that include members of the AP-1 family.
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Choudhury GG. A linear signal transduction pathway involving phosphatidylinositol 3-kinase, protein kinase Cepsilon, and MAPK in mesangial cells regulates interferon-gamma-induced STAT1alpha transcriptional activation. J Biol Chem 2004; 279:27399-409. [PMID: 15082710 DOI: 10.1074/jbc.m403530200] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Interferon-gamma (IFN-gamma) exerts an pleiotropic effect in mesangial cells in inflammatory glomerular diseases. The biologic effect of IFN-gamma is mediated by STAT1alpha. The precise mechanism by which IFN-gamma stimulates the transcriptional activity of STAT1alpha is poorly understood. I investigated the role of protein kinase C (PKC) epsilon in regulating the transcriptional activation of STAT1alpha in mesangial cells. IFN-gamma increased PKCepsilon activity in a time-dependent manner with a concomitant increase in STAT1alpha transcriptional activity. Expression of constitutively active PKCepsilon mimicked the effect of IFN-gamma on STAT1alpha-dependent transcription. Expression of dominant negative PKCepsilon inhibited IFN-gamma-induced STAT1alpha-dependent transcription. Ly294002, a pharmacological inhibitor of phosphatidylinositol (PI) 3-kinase, blocked IFN-gamma-induced PKCepsilon activity and resulted in inhibition of STAT1alpha transcriptional activity but had no effect on STAT1alpha tyrosine phosphorylation and STAT1alpha-DNA complex formation. A PKC inhibitor, H7, also had no effect on STAT1alpha tyrosine phosphorylation and DNA binding. However, Ly294002 and H7 blocked IFN-gamma-induced serine phosphorylation of STAT1alpha. These data indicate that PI 3 kinase-dependent PKCepsilon regulates STAT1alpha transcriptional activity in the absence of any effect on its DNA binding capability. In addition to activating PKCepsilon, IFN-gamma increased MAPK activity, resulting in transcriptional activation of Elk-1, a nuclear target of MAPK. Ly294002 or a dominant negative PI 3-kinase significantly blocked IFN-gamma-induced MAPK activity. On the other hand, ectopic expression of constitutively active PKCepsilon significantly increased MAPK activity. IFN-gamma-stimulated MAPK phosphorylated STAT1alpha in vitro. Inhibition of MAPK activity blocked IFN-gamma-induced serine phosphorylation of STAT1alpha; but its tyrosine phosphorylation and DNA binding were partially inhibited. Finally, expression of dominant negative MAPK significantly inhibited IFN-gamma-induced STAT1alpha-dependent transcription. These data provide the first evidence that IFN-gamma stimulates PKCepsilon in a PI 3-kinase-sensitive manner to activate MAPK, which regulates STAT1alpha transcriptional activity.
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Affiliation(s)
- Goutam Ghosh Choudhury
- Department of Medicine, University of Texas Health Science Center at San Antonio, 78229-3900, USA
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