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Xu T, Gao P, Huang Y, Wu M, Yi J, Zhou Z, Zhao X, Jiang T, Liu H, Qin T, Yang Z, Wang X, Bao T, Chen J, Zhao S, Yin G. Git1-PGK1 interaction achieves self-protection against spinal cord ischemia-reperfusion injury by modulating Keap1/Nrf2 signaling. Redox Biol 2023; 62:102682. [PMID: 36963288 PMCID: PMC10053403 DOI: 10.1016/j.redox.2023.102682] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 03/13/2023] [Accepted: 03/17/2023] [Indexed: 03/22/2023] Open
Abstract
Spinal cord ischemia-reperfusion (IR) injury (SCIRI) is a significant secondary injury that causes damage to spinal cord neurons, leading to the impairment of spinal cord sensory and motor functions. Excessive reactive oxygen species (ROS) production is considered one critical mechanism of neuron damage in SCIRI. Nonetheless, the molecular mechanisms underlying the resistance of neurons to ROS remain elusive. Our study revealed that the deletion of Git1 in mice led to poor recovery of spinal cord motor function after SCIRI. Furthermore, we discovered that Git1 has a beneficial effect on neuron resistance to ROS production. Mechanistically, Git1 interacted with PGK1, regulated PGK1 phosphorylation at S203, and affected the intermediate products of glycolysis in neurons. The influence of Git1 on glycolysis regulates the dimerization of Keap1, which leads to changes in Nrf2 ubiquitination and plays a role in resisting ROS. Collectively, we show that Git1 regulates the Keap1/Nrf2 axis to resist ROS in a PGK1-dependent manner and thus is a potential therapeutic target for SCIRI.
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Affiliation(s)
- Tao Xu
- Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, 210029, China; Division of Spine Surgery, Department of Orthopedic Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School Nanjing, 210008, China; Jiangsu Institute of Functional Reconstruction and Rehabilitation, Nanjing, Jiangsu, 210029, China
| | - Peng Gao
- Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, 210029, China; Jiangsu Institute of Functional Reconstruction and Rehabilitation, Nanjing, Jiangsu, 210029, China
| | - Yifan Huang
- Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, 210029, China; Jiangsu Institute of Functional Reconstruction and Rehabilitation, Nanjing, Jiangsu, 210029, China
| | - Mengyuan Wu
- Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, 210029, China; Jiangsu Institute of Functional Reconstruction and Rehabilitation, Nanjing, Jiangsu, 210029, China
| | - Jiang Yi
- Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, 210029, China; Jiangsu Institute of Functional Reconstruction and Rehabilitation, Nanjing, Jiangsu, 210029, China
| | - Zheng Zhou
- Department of Emergency Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, Jiangsu, China; Jiangsu Institute of Functional Reconstruction and Rehabilitation, Nanjing, Jiangsu, 210029, China
| | - Xuan Zhao
- Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, 210029, China; Jiangsu Institute of Functional Reconstruction and Rehabilitation, Nanjing, Jiangsu, 210029, China
| | - Tao Jiang
- Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, 210029, China; Jiangsu Institute of Functional Reconstruction and Rehabilitation, Nanjing, Jiangsu, 210029, China
| | - Hao Liu
- Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, 210029, China; Jiangsu Institute of Functional Reconstruction and Rehabilitation, Nanjing, Jiangsu, 210029, China
| | - Tao Qin
- Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, 210029, China; Jiangsu Institute of Functional Reconstruction and Rehabilitation, Nanjing, Jiangsu, 210029, China
| | - Zhenqi Yang
- Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, 210029, China; Jiangsu Institute of Functional Reconstruction and Rehabilitation, Nanjing, Jiangsu, 210029, China
| | - Xiaowei Wang
- Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, 210029, China; Jiangsu Institute of Functional Reconstruction and Rehabilitation, Nanjing, Jiangsu, 210029, China
| | - Tianyi Bao
- Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, 210029, China; Jiangsu Institute of Functional Reconstruction and Rehabilitation, Nanjing, Jiangsu, 210029, China
| | - Jian Chen
- Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, 210029, China; Jiangsu Institute of Functional Reconstruction and Rehabilitation, Nanjing, Jiangsu, 210029, China.
| | - Shujie Zhao
- Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, 210029, China; Jiangsu Institute of Functional Reconstruction and Rehabilitation, Nanjing, Jiangsu, 210029, China.
| | - Guoyong Yin
- Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, 210029, China; Jiangsu Institute of Functional Reconstruction and Rehabilitation, Nanjing, Jiangsu, 210029, China.
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Zhang Z, Hu P, Wang Z, Qiu X, Chen Y. BDNF promoted osteoblast migration and fracture healing by up-regulating integrin β1 via TrkB-mediated ERK1/2 and AKT signalling. J Cell Mol Med 2020; 24:10792-10802. [PMID: 32803867 PMCID: PMC7521296 DOI: 10.1111/jcmm.15704] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 07/12/2020] [Accepted: 07/14/2020] [Indexed: 12/17/2022] Open
Abstract
Brain‐derived neurotrophic factor (BDNF) has been reported to participate in fracture healing, whereas the mechanism is still unclear. Since osteoblast migration is important for fracture healing, investigating effects of BDNF on osteoblasts migration may help to reveal its mechanism. Here, MC3T3‐E1 cells were used in vitro while closed femur fracture mice were applied in vivo. Cells migration was assessed with Transwell assay. The protein expression was analysed by immunoblotting. X‐ray and Micro‐CT were performed at different time after fracture. Our results showed that BDNF promoted MC3T3‐E1 cells migration, integrin β1 expression and ERK1/2 and AKT phosphorylation. K252a, a specific inhibitor for TrkB, suppressed BDNF‐induced migration, integrin β1 expression and activation of ERK1/2 and AKT. PD98059 (an ERK1/2 inhibitor) and LY294002 (an AKT inhibitor) both inhibited BDNF‐induced migration and integrin β1 expression while integrin β1 blocking antibody only suppressed cell migration. X‐ray and Micro‐CT analyses showed that the adenoviral carried integrin β1 shRNA group had slower fracture healing at 7 and 21 days, but not 35 days compared to the control group. Thus, we proposed that BDNF stimulated MC3T3‐E1 cells migration by up‐regulating integrin β1 via TrkB mediated ERK1/2 and AKT signalling, and this may help to enhance the fracture healing.
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Affiliation(s)
- Zitao Zhang
- Department of Orthopedics, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Polu Hu
- Nanjing Red Cross Blood Center, Nanjing, China
| | - Zhen Wang
- Department of Orthopedics, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Xusheng Qiu
- Department of Orthopedics, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Yixin Chen
- Department of Orthopedics, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
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3
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Shao X, Liu L, Wei F, Liu Y, Wang F, Yi J, Sun L, Huang Y, Song Z, Yin W, Zhao H, Li Y. Fas and GIT1 signalling in the prefrontal cortex mediate behavioural sensitization to methamphetamine in mice. Brain Res Bull 2020; 164:361-371. [PMID: 32777257 DOI: 10.1016/j.brainresbull.2020.07.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 06/28/2020] [Accepted: 07/03/2020] [Indexed: 12/24/2022]
Abstract
PURPOSE Repeated methamphetamine (METH) administration in mice readily produces behavioural sensitization, but the underlying mechanisms remain elusive. The present research aimed to identify new targets affecting METH-induced behavioural sensitization. METHODS We first established a mouse model of METH-induced behavioural sensitization. To characterize the animal model, we performed behavioural tests at different stages of behavioural sensitization and simultaneously detected changes in several neurotransmitters in the prefrontal cortex (PFC). Next, we perfromed RNA sequencing (RNA-seq) to screen new targets, which were subsequently and verified by RT-PCR and western blot. Finally, we confirmed the roles of the new targets in METH-induced behavioural sensitization by injection of overexpressed lentiviruses and further detected related protein levels by western blot and histological changes by haematoxylin and eosin (HE) staining. RESULTS We successfully established a mouse model of METH-induced behavioural sensitization. The locomotor activities of the mice changed at different stages of sensitization, accompanied by changes in the levels of DA, 5-HT, GABA and glutamate. For RNA-seq analysis, we chose Fas as target, meanwhile, we chose GIT1 as target through literature. The detection of gene expression by RT-PCR indicated that METH-sensitized mice exhibited decreased levels of Fas, MEK1 and CREB and increased levels of Erk1/2 in the PFC. Western blot analysis revealed decreased Fas, GIT1, MEK1 and phosphorylated CREB levels and increased phosphorylated Erk1/2 levels in METH-sensitized mice. Injection of Fas and GIT1 injection showed that overexpression of Fas and GIT1 inhibited the induction of METH sensitization and reversed the changes in neurotransmitter levels and related protein levels, including MEK1, phosphorylated CREB and phosphorylated Erk1/2, in METH-sensitized mice. Overexpression of Fas and GIT1 also reduced histological lesions induced by METH. CONCLUSION The findings indicated that the development of behavioural sensitization to METH may be mediated by Fas and GIT1 through the MEK1-Erk1/2-CREB pathway.
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Affiliation(s)
- Xiaotong Shao
- National Engineering Laboratory for Druggable Gene and Protein Screening, Northeast Normal University, Changchun, 130024, China
| | - Lei Liu
- National Engineering Laboratory for Druggable Gene and Protein Screening, Northeast Normal University, Changchun, 130024, China
| | - Fuyao Wei
- National Engineering Laboratory for Druggable Gene and Protein Screening, Northeast Normal University, Changchun, 130024, China
| | - Yucui Liu
- Research Center of Agriculture and Medicine Gene Engineering of Ministry of Education, Northeast Normal University, Changchun, 130024, China
| | - Fei Wang
- Research Center of Agriculture and Medicine Gene Engineering of Ministry of Education, Northeast Normal University, Changchun, 130024, China
| | - Jingwen Yi
- National Engineering Laboratory for Druggable Gene and Protein Screening, Northeast Normal University, Changchun, 130024, China
| | - Luguo Sun
- Research Center of Agriculture and Medicine Gene Engineering of Ministry of Education, Northeast Normal University, Changchun, 130024, China
| | - Yanxin Huang
- National Engineering Laboratory for Druggable Gene and Protein Screening, Northeast Normal University, Changchun, 130024, China
| | - Zhenbo Song
- Research Center of Agriculture and Medicine Gene Engineering of Ministry of Education, Northeast Normal University, Changchun, 130024, China
| | - Wu Yin
- Research Center of Agriculture and Medicine Gene Engineering of Ministry of Education, Northeast Normal University, Changchun, 130024, China.
| | - Huiying Zhao
- Department of Geriatrics, The First Hospital of Jilin University, Changchun, 130021, China
| | - Yunxin Li
- National Engineering Laboratory for Druggable Gene and Protein Screening, Northeast Normal University, Changchun, 130024, China
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Fan X, Yan C, Ma Y, Li L, Zhang M, Zhan J. Effect and mechanism of ginsenoside Rg1 on synaptic plasticity of oxygen-glucose deprivation/reoxygenation-induced neuronal injury. Pharmacogn Mag 2020. [DOI: 10.4103/pm.pm_541_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Zhang Z, Hu P, Xiong J, Wang S. Inhibiting GIT1 reduces the growth, invasion, and angiogenesis of osteosarcoma. Cancer Manag Res 2018; 10:6445-6455. [PMID: 30555255 PMCID: PMC6278701 DOI: 10.2147/cmar.s181066] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Background GIT1, a scaffold protein with ubiquitous multi-domain, is involved in many cellular processes. In recent years, it was proved that GIT1 participated in various tumors’ growth or metastasis. However, the biological function of GIT1 in osteosarcoma is still unclear. In this study, we aimed to investigate the role and mechanism of GIT1 in osteosarcoma. Materials and methods Human osteosarcoma tissues were obtained to investigate the distribution of GIT1. Adequate osteosarcoma cells were stably infected with lentivirus to knockdown GIT1 level and then was used to carry out cell invasion and vascular endothelial growth factor (VEGF) assay in vitro. Orthotopic femoral osteosarcoma model was constructed to investigate the growth, invasion, and angiogenesis in vivo. Western blot was used to detect extracellular signal-regulated kinase (ERK1/2) activation and hypoxia-inducible factor-1 (HIF-1α) expression. Results In this study, we found that GIT1 was distributed in human osteosarcoma tissues and highly expressed in osteosarcoma (OS) cells. Knockdown of GIT1 inhibited cell invasion and VEGF release in vitro and suppressed tumor growth, invasion, and angiogenesis in vivo. Furthermore, knockdown of GIT1 substantially downregulated the protein levels of p-ERK and HIF-1α in OST cells and inhibition of p-ERK by PD98059 could significantly decrease the expression of HIF-1α and concentration of VEGF in GIT1-shRNA-treated cells. Conclusion GIT1 knockdown can effectively inhibit the growth, invasion, and angiogenesis of osteosarcoma. Thus, GIT1 might act as an oncogenic factor in osteosarcoma and could be a potential molecular target for osteosarcoma gene therapy.
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Affiliation(s)
- Zitao Zhang
- Department of Orthopedics, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008, China,
| | - Polu Hu
- Nanjing Red Cross Blood Center, Nanjing 210003, China
| | - Jin Xiong
- Department of Orthopedics, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008, China,
| | - Shoufeng Wang
- Department of Orthopedics, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008, China,
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Chen J, Wang Q, Zhou W, Zhou Z, Tang PY, Xu T, Liu W, Li LW, Cheng L, Zhou ZM, Fan J, Yin GY. GPCR kinase 2-interacting protein-1 protects against ischemia-reperfusion injury of the spinal cord by modulating ASK1/JNK/p38 signaling. FASEB J 2018; 32:fj201800548. [PMID: 29912587 DOI: 10.1096/fj.201800548] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
GPCR kinase 2-interacting protein-1 (GIT1) is a scaffold protein that plays an important role in cell adaptation, proliferation, migration, and differentiation; however, the role of GIT1 in the regulation of neuronal death after spinal cord injury remains obscure. Here, we demonstrate that GIT1 deficiency remarkably increased neuronal apoptosis and enhanced JNK/p38 signaling, which resulted in stronger motor deficits by ischemia-reperfusion in vivo, consistent with the finding of oxygen-glucose deprivation/reoxygenation-induced neuronal injury in vitro. After treatment with JNK and p38 inhibitors, abnormally necroptotic cell death caused by GIT1 knockdown could be partially rescued, with the recovery of neuronal viability, which was still poorer than that in control neurons. Meanwhile, overactivation of JNK/p38 after GIT1 depletion was concomitant with excessive activity of apoptosis signal-regulating kinase-1 (ASK1) that could be abolished by ASK1 silencing in HEK293T cells. Finally, GIT1 could disrupt the oligomerization of ASK1 via interaction between the synaptic localization domain that contains the coiled-coil (CC)-2 domain of GIT1 and the C-terminal CC domain of ASK1. It suppressed the autophosphorylation of ASK1 and led to decreasing activity of the ASK1/JNK/p38 pathway. These data reveal a protective role for GIT1 in neuronal damage by modulating ASK1/JNK/p38 signaling.-Chen, J., Wang, Q., Zhou, W., Zhou, Z., Tang, P.-Y., Xu, T., Liu, W., Li, L.-W., Cheng, L., Zhou, Z.-M., Fan, J., Yin, G.-Y. GPCR kinase 2-interacting protein-1 protects against ischemia-reperfusion injury of the spinal cord by modulating ASK1/JNK/p38 signaling.
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Affiliation(s)
- Jian Chen
- Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Qian Wang
- Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Wei Zhou
- Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Zheng Zhou
- Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Peng-Yu Tang
- Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Tao Xu
- Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Wei Liu
- Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Lin-Wei Li
- Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Lin Cheng
- Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Zhi-Min Zhou
- Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Jin Fan
- Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Guo-Yong Yin
- Department of Orthopedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
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Edogawa S, Peters SA, Jenkins GD, Gurunathan SV, Sundt WJ, Johnson S, Lennon RJ, Dyer RB, Camilleri M, Kashyap PC, Farrugia G, Chen J, Singh RJ, Grover M. Sex differences in NSAID-induced perturbation of human intestinal barrier function and microbiota. FASEB J 2018; 32:fj201800560R. [PMID: 29897814 PMCID: PMC6219825 DOI: 10.1096/fj.201800560r] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 05/21/2018] [Indexed: 12/12/2022]
Abstract
Intestinal barrier function and microbiota are integrally related and play critical roles in maintenance of host physiology. Sex is a key biologic variable for several disorders. Our aim was to determine sex-based differences in response to perturbation and subsequent recovery of intestinal barrier function and microbiota in healthy humans. Twenty-three volunteers underwent duodenal biopsies, mucosal impedance, and in vivo permeability measurement. Permeability testing was repeated after administration of indomethacin, then 4 to 6 wk after its discontinuation. Duodenal and fecal microbiota composition was determined using 16S rRNA amplicon sequencing. Healthy women had lower intestinal permeability and higher duodenal and fecal microbial diversity than healthy men. Intestinal permeability increases after indomethacin administration in both sexes. However, only women demonstrated decreased fecal microbial diversity, including an increase in Prevotella abundance, after indomethacin administration. Duodenal microbiota composition did not show sex-specific changes. The increase in permeability and microbiota changes normalized after discontinuation of indomethacin. In summary, women have lower intestinal permeability and higher microbial diversity. Intestinal permeability is sensitive to perturbation but recovers to baseline. Gut microbiota in women is sensitive to perturbation but appears to be more stable in men. Sex-based differences in intestinal barrier function and microbiome should be considered in future studies.-Edogawa, S., Peters, S. A., Jenkins, G. D., Gurunathan, S. V., Sundt, W. J., Johnson, S., Lennon, R. J., Dyer, R. B., Camilleri, M., Kashyap, P. C., Farrugia, G., Chen, J., Singh, R. J., Grover, M. Sex differences in NSAID-induced perturbation of human intestinal barrier function and microbiota.
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Affiliation(s)
- Shoko Edogawa
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA
| | - Stephanie A. Peters
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA
| | - Gregory D. Jenkins
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, USA
- Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Wendy J. Sundt
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA
| | - Stephen Johnson
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, USA
- Center for Individualized Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Ryan J. Lennon
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, USA
| | - Roy B. Dyer
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - Michael Camilleri
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA
| | - Purna C. Kashyap
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA
| | - Gianrico Farrugia
- Division of Gastroenterology and Hepatology, Mayo Clinic, Jacksonville, Florida, USA
| | - Jun Chen
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, USA
| | - Ravinder J. Singh
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - Madhusudan Grover
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA
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Zhang Z, Zhang Y, Zhou Z, Shi H, Qiu X, Xiong J, Chen Y. BDNF regulates the expression and secretion of VEGF from osteoblasts via the TrkB/ERK1/2 signaling pathway during fracture healing. Mol Med Rep 2017; 15:1362-1367. [PMID: 28098876 DOI: 10.3892/mmr.2017.6110] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 08/09/2016] [Indexed: 11/05/2022] Open
Abstract
Brain‑derived neurotrophic factor (BDNF), a member of the neurotropic family, is expressed in osteoblast‑like cells of a fracture callus, however, its role in fracture healing remains to be fully elucidated. Osteoblasts isolated from Sprague Dawley rats were stimulated by BDNF in a dose‑ and time‑dependent manner. Immunoblotting and immunofluorescence was used to detect the expression and distribution of targeted proteins. The concentration of vascular endothelial growth factor (VEGF) released in medium was determined using an ELISA. PD98059 and K252a were used to investigate the signaling pathways that may be involved. The present study demonstrated that BDNF was involved in fracture repair by controlling the expression and secretion of VEGF from osteoblasts, which predominantly drives angiogenesis during fracture healing. Tropomyosin‑related kinase B (TrkB), the specific receptor of BDNF, was shown to be expressed at high levels in the osteoblasts. Following BDNF stimulation, TrkB and extracellular signal‑regulated kinase 1/2 (ERK1/2) were rapidly activated. The inhibition of TrkB by K252a decreased the expression and secretion of VEGF, and suppressed the phosphorylation level of ERK1/2. PD98059, an antagonist of ERK1/2, elicited the same effects on VEGF from the BDNF‑stimulated osteoblasts, however, it did not affect the phosphorylation of TrkB. In conclusion, during fracture healing, BDNF was found to stimulate the expression and secretion of VEGF from osteoblasts via the TrkB/ERK1/2 signaling pathway.
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Affiliation(s)
- Zitao Zhang
- Department of Orthopedics, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu 210008, P.R. China
| | - Yan Zhang
- Department of Orthopedics, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu 210008, P.R. China
| | - Zhengnan Zhou
- Department of Orthopedics, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu 210008, P.R. China
| | - Hongfei Shi
- Department of Orthopedics, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu 210008, P.R. China
| | - Xusheng Qiu
- Department of Orthopedics, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu 210008, P.R. China
| | - Jin Xiong
- Department of Orthopedics, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu 210008, P.R. China
| | - Yixin Chen
- Department of Orthopedics, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu 210008, P.R. China
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Li YS, Qin LX, Liu J, Xia WL, Li JP, Shen HL, Gao WQ. GIT1 enhances neurite outgrowth by stimulating microtubule assembly. Neural Regen Res 2016; 11:427-34. [PMID: 27127481 PMCID: PMC4829007 DOI: 10.4103/1673-5374.179054] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
GIT1, a G-protein-coupled receptor kinase interacting protein, has been reported to be involved in neurite outgrowth. However, the neurobiological functions of the protein remain unclear. In this study, we found that GIT1 was highly expressed in the nervous system, and its expression was maintained throughout all stages of neuritogenesis in the brain. In primary cultured mouse hippocampal neurons from GIT1 knockout mice, there was a significant reduction in total neurite length per neuron, as well as in the average length of axon-like structures, which could not be prevented by nerve growth factor treatment. Overexpression of GIT1 significantly promoted axon growth and fully rescued the axon outgrowth defect in the primary hippocampal neuron cultures from GIT1 knockout mice. The GIT1 N terminal region, including the ADP ribosylation factor-GTPase activating protein domain, the ankyrin domains and the Spa2 homology domain, were sufficient to enhance axonal extension. Importantly, GIT1 bound to many tubulin proteins and microtubule-associated proteins, and it accelerated microtubule assembly in vitro. Collectively, our findings suggest that GIT1 promotes neurite outgrowth, at least partially by stimulating microtubule assembly. This study provides new insight into the cellular and molecular pathogenesis of GIT1-associated neurological diseases.
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Affiliation(s)
- Yi-Sheng Li
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Stem Cell Research Center, Ren Ji Hospital, School of Biomedical Engineering & Med-X Research Institute, Shanghai Jiao Tong University, Shanghai, China
| | - Li-Xia Qin
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Stem Cell Research Center, Ren Ji Hospital, School of Biomedical Engineering & Med-X Research Institute, Shanghai Jiao Tong University, Shanghai, China
| | - Jie Liu
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Stem Cell Research Center, Ren Ji Hospital, School of Biomedical Engineering & Med-X Research Institute, Shanghai Jiao Tong University, Shanghai, China
| | - Wei-Liang Xia
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Stem Cell Research Center, Ren Ji Hospital, School of Biomedical Engineering & Med-X Research Institute, Shanghai Jiao Tong University, Shanghai, China
| | - Jian-Ping Li
- Department of Neurology, Shanghai Renji Hospital, Shanghai, China
| | - Hai-Lian Shen
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Stem Cell Research Center, Ren Ji Hospital, School of Biomedical Engineering & Med-X Research Institute, Shanghai Jiao Tong University, Shanghai, China
| | - Wei-Qiang Gao
- State Key Laboratory of Oncogenes and Related Genes, Renji-Med X Stem Cell Research Center, Ren Ji Hospital, School of Biomedical Engineering & Med-X Research Institute, Shanghai Jiao Tong University, Shanghai, China; Collarative Innovation Center of Systems Biomedicine, Shanghai Jiao Tong University, Shanghai, China
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Kurko D, Kapui Z, Nagy J, Lendvai B, Kolok S. Analysis of functional selectivity through G protein-dependent and -independent signaling pathways at the adrenergic α(2C) receptor. Brain Res Bull 2014; 107:89-101. [PMID: 25080296 DOI: 10.1016/j.brainresbull.2014.07.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 07/15/2014] [Accepted: 07/17/2014] [Indexed: 01/01/2023]
Abstract
Although G protein-coupled receptors (GPCRs) are traditionally categorized as Gs-, Gq-, or Gi/o-coupled, their signaling is regulated by multiple mechanisms. GPCRs can couple to several effector pathways, having the capacity to interact not only with more than one G protein subtype but also with alternative signaling or effector proteins such as arrestins. Moreover, GPCR ligands can have different efficacies for activating these signaling pathways, a characteristic referred to as biased agonism or functional selectivity. In this work our aim was to detect differences in the ability of various agonists acting at the α2C type of adrenergic receptors (α2C-ARs) to modulate cAMP accumulation, cytoplasmic Ca(2+) release, β-arrestin recruitment and receptor internalization. A detailed comparative pharmacological characterization of G protein-dependent and -independent signaling pathways was carried out using adrenergic agonists (norepinephrine, phenylephrine, brimonidine, BHT-920, oxymetazoline, clonidine, moxonidine, guanabenz) and antagonists (MK912, yohimbine). As initial analysis of agonist Emax and EC50 values suggested possible functional selectivity, ligand bias was quantified by applying the relative activity scale and was compared to that of the endogenous agonist norepinephrine. Values significantly different from 0 between pathways indicated an agonist that promoted different level of activation of diverse effector pathways most likely due to the stabilization of a subtly different receptor conformation from that induced by norepinephrine. Our results showed that a series of agonists acting at the α2C-AR displayed different degree of functional selectivity (bias factors ranging from 1.6 to 36.7) through four signaling pathways. As signaling via these pathways seems to have distinct functional and physiological outcomes, studying all these stages of receptor activation could have further implications for the development of more selective therapeutics with improved efficacy and/or fewer side effects.
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Affiliation(s)
- Dalma Kurko
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary.
| | - Zoltán Kapui
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - József Nagy
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Balázs Lendvai
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Sándor Kolok
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
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GluN3A expression restricts spine maturation via inhibition of GIT1/Rac1 signaling. Proc Natl Acad Sci U S A 2013; 110:20807-12. [PMID: 24297929 DOI: 10.1073/pnas.1312211110] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
NMDA-type glutamate receptors (NMDARs) guide the activity-dependent remodeling of excitatory synapses and associated dendritic spines during critical periods of postnatal brain development. Whereas mature NMDARs composed of GluN1 and GluN2 subunits mediate synapse plasticity and promote spine growth and stabilization, juvenile NMDARs containing GluN3A subunits are thought to inhibit these processes via yet unknown mechanisms. Here, we report that GluN3A binds G protein-coupled receptor kinase-interacting protein (GIT1), a postsynaptic scaffold that assembles actin regulatory complexes, including the Rac1 guanine nucleotide exchange factor βPIX, to promote Rac1 activation in spines. Binding to GluN3A limits the synaptic localization of GIT1 and its ability to complex βPIX, leading to decreased Rac1 activation and reduced spine density and size in primary cultured neurons. Conversely, knocking out GluN3A favors the formation of GIT1/βPIX complexes and increases the activation of Rac1 and its main effector p21-activated kinase. We further show that binding of GluN3A to GIT1 is regulated by synaptic activity, a response that might restrict the negative regulatory effects of GluN3A on actin signaling to inactive synapses. Our results identify inhibition of Rac1/p21-activated kinase actin signaling pathways as an activity-dependent mechanism mediating the inhibitory effects of GluN3A on spine morphogenesis.
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