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Jiang P, Zhao S, Li X, Hu S, Chen S, Liang Y, Zhang L, Lu L, Fang G, Yang L, Huang Y, Miller H, Guan F, Lei J, Liu C. Dedicator of cytokinesis 8 (DOCK8) mutation impairs the differentiation of helper T cells by regulating the glycolytic pathway of CD4 + T cells. MedComm (Beijing) 2024; 5:e747. [PMID: 39329018 PMCID: PMC11424684 DOI: 10.1002/mco2.747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 08/28/2024] [Accepted: 08/29/2024] [Indexed: 09/28/2024] Open
Abstract
Dedicator of cytokinesis 8 (DOCK8) deficiency is a primary immunodeficiency disease caused by mutations in exon 45 of the DOCK8 gene. The clinical signs primarily consist of increased serum IgE levels, eczema, repeated skin infections, allergies, and upper respiratory tract infections. Using CRISPR/Cas9 technology, we generated a DOCK8 exon 45 mutation in mice, mirroring the mutation found in patients. The results indicated that DOCK8 mutation impairs peripheral T cell homeostasis, disrupts regulatory T cells (Tregs) development, increases ICOS expression in Tregs within peripheral lymph nodes (pLn), and promotes Th17 cell differentiation within the spleen and pLn. Upon virus infection, DOCK8 mutation CD4+ T cells have a Th2 effector fate. RNA-bulk sequencing data revealed alternations in the mTOR pathway of DOCK8 mutant CD4+ T cells. We observed that DOCK8 mutation upregulates the glycolysis levels in CD4+ T cells, which is related to the Akt/mTOR/S6/HIF-1α pathway. In summary, our research elucidates that DOCK8 regulates the differentiation of helper T cells by modulating the glycolytic pathway in CD4+ T cells, thereby advancing the comprehension and offering potential treatment of diseases in DOCK8-deficient patients.
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Affiliation(s)
- Panpan Jiang
- Department of Pathogen Biology School of Basic Medicine Tongji Medical College and State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases Huazhong University of Science and Technology Wuhan China
| | - Siyu Zhao
- Department Immunology School of Medicine Yangtze University Jingzhou China
| | - Xiaoyu Li
- Department of Pathogen Biology School of Basic Medicine Tongji Medical College and State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases Huazhong University of Science and Technology Wuhan China
| | - Shiyan Hu
- Department of Pathogen Biology School of Basic Medicine Tongji Medical College and State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases Huazhong University of Science and Technology Wuhan China
| | - Shuhan Chen
- Department of Pathogen Biology School of Basic Medicine Tongji Medical College and State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases Huazhong University of Science and Technology Wuhan China
| | - Yinming Liang
- Center of Disease Model and Immunology Hunan Academy of Chinese Medicine Changsha China
| | - Lichen Zhang
- Laboratory of Genetic Regulators in the Immune System School of Medical Technology Xinxiang Medical University Xinxiang China
| | - Liaoxun Lu
- Laboratory of Genetic Regulators in the Immune System School of Medical Technology Xinxiang Medical University Xinxiang China
| | - Guofeng Fang
- Department of Pathogen Biology School of Basic Medicine Tongji Medical College and State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases Huazhong University of Science and Technology Wuhan China
| | - Lu Yang
- Department of Pathogen Biology School of Basic Medicine Tongji Medical College and State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases Huazhong University of Science and Technology Wuhan China
| | - Yanmei Huang
- Department of Pathogen Biology School of Basic Medicine Tongji Medical College and State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases Huazhong University of Science and Technology Wuhan China
| | - Heather Miller
- Cytek Biosciences R&D Clinical Reagents Fremont California USA
| | - Fei Guan
- Department of Pathogen Biology School of Basic Medicine Tongji Medical College and State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases Huazhong University of Science and Technology Wuhan China
| | - Jiahui Lei
- Department of Pathogen Biology School of Basic Medicine Tongji Medical College and State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases Huazhong University of Science and Technology Wuhan China
| | - Chaohong Liu
- Department of Pathogen Biology School of Basic Medicine Tongji Medical College and State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases Huazhong University of Science and Technology Wuhan China
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Zhang Q, Zhang C, Kang C, Zhu J, He Q, Li H, Tong Q, Wang M, Zhang L, Xiong X, Wang Y, Qu H, Zheng H, Zheng Y. Liraglutide Promotes Diabetic Wound Healing via Myo1c/Dock5. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024:e2405987. [PMID: 39159301 DOI: 10.1002/advs.202405987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Revised: 07/26/2024] [Indexed: 08/21/2024]
Abstract
Non-healing diabetic wounds and ulcer complications, with persistent cell dysfunction and obstructed cellular processes, are leading causes of disability and death in patients with diabetes. Currently, there is a lack of guideline-recommended hypoglycemic drugs in clinical practice, likely due to limited research and unclear mechanisms. In this study, it is demonstrated that liraglutide significantly accelerates wound closure in diabetic mouse models (db/db mice and streptozotocin-induced mice) by improving re-epithelialization, collagen deposition, and extracellular matrix remodeling, and enhancing the proliferation, migration, and adhesion functions of keratinocytes. However, these effects of improved healing by liraglutide are abrogated in dedicator of cytokinesis 5 (Dock5) keratinocyte-specific knockout mice. Mechanistically, liraglutide induces cellular function through stabilization of unconventional myosin 1c (Myo1c). Liraglutide directly binds to Myo1c at arginine 93, enhancing the Myo1c/Dock5 interaction by targeting Dock5 promoter and thus promoting the proliferation, migration, and adhesion of keratinocytes. Therefore, this study provides insights into liraglutide biology and suggests it may be an effective treatment for diabetic patients with wound-healing pathologies.
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Affiliation(s)
- Qian Zhang
- School of Life Sciences, Chongqing University, Chongqing, 401331, China
- Department of Endocrinology, Translational Research of Diabetes Key Laboratory of Chongqing Education Commission of China, the Second Affiliated Hospital of Army Medical University, Chongqing, 400037, China
- Department of Pharmacy, the Second Affiliated Hospital of Army Medical University, Chongqing, 400037, China
| | - Chunlin Zhang
- School of Life Sciences, Chongqing University, Chongqing, 401331, China
- Department of Endocrinology, Translational Research of Diabetes Key Laboratory of Chongqing Education Commission of China, the Second Affiliated Hospital of Army Medical University, Chongqing, 400037, China
| | - Changjiang Kang
- Department of Endocrinology, Translational Research of Diabetes Key Laboratory of Chongqing Education Commission of China, the Second Affiliated Hospital of Army Medical University, Chongqing, 400037, China
- Department of Laboratory Medicine, Chongqing University Three Gorges Hospital, School of Medicine, Chongqing University, Chongqing, 404000, China
| | - Jiaran Zhu
- Department of Endocrinology, Translational Research of Diabetes Key Laboratory of Chongqing Education Commission of China, the Second Affiliated Hospital of Army Medical University, Chongqing, 400037, China
| | - Qingshan He
- Department of Endocrinology, Translational Research of Diabetes Key Laboratory of Chongqing Education Commission of China, the Second Affiliated Hospital of Army Medical University, Chongqing, 400037, China
| | - Hongwei Li
- Department of Medicinal Chemistry, Army Medical University, Chongqing, 400038, China
| | - Qiang Tong
- Department of Endocrinology, Translational Research of Diabetes Key Laboratory of Chongqing Education Commission of China, the Second Affiliated Hospital of Army Medical University, Chongqing, 400037, China
| | - Min Wang
- Department of Endocrinology, Translational Research of Diabetes Key Laboratory of Chongqing Education Commission of China, the Second Affiliated Hospital of Army Medical University, Chongqing, 400037, China
| | - Linlin Zhang
- Department of Endocrinology, Translational Research of Diabetes Key Laboratory of Chongqing Education Commission of China, the Second Affiliated Hospital of Army Medical University, Chongqing, 400037, China
| | - Xin Xiong
- Department of Endocrinology, Translational Research of Diabetes Key Laboratory of Chongqing Education Commission of China, the Second Affiliated Hospital of Army Medical University, Chongqing, 400037, China
| | - Yuren Wang
- Department of Endocrinology, Translational Research of Diabetes Key Laboratory of Chongqing Education Commission of China, the Second Affiliated Hospital of Army Medical University, Chongqing, 400037, China
| | - Hua Qu
- Department of Endocrinology, Translational Research of Diabetes Key Laboratory of Chongqing Education Commission of China, the Second Affiliated Hospital of Army Medical University, Chongqing, 400037, China
| | - Hongting Zheng
- Department of Endocrinology, Translational Research of Diabetes Key Laboratory of Chongqing Education Commission of China, the Second Affiliated Hospital of Army Medical University, Chongqing, 400037, China
| | - Yi Zheng
- Department of Endocrinology, Translational Research of Diabetes Key Laboratory of Chongqing Education Commission of China, the Second Affiliated Hospital of Army Medical University, Chongqing, 400037, China
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Li YY, Murai K, Lyu J, Honda M. Roles Played by DOCK11, a Guanine Nucleotide Exchange Factor, in HBV Entry and Persistence in Hepatocytes. Viruses 2024; 16:745. [PMID: 38793626 PMCID: PMC11125634 DOI: 10.3390/v16050745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 04/28/2024] [Accepted: 05/05/2024] [Indexed: 05/26/2024] Open
Abstract
HBV infection is challenging to cure due to the persistence of viral covalently closed circular viral DNA (cccDNA). The dedicator of cytokinesis 11 (DOCK11) is recognized as a guanine nucleotide exchange factor (GEF) for CDC42 that has been reported to be required for HBV persistence. DOCK11 is expressed in both the cytoplasm and nucleus of human hepatocytes and is functionally associated with retrograde trafficking proteins Arf-GAP with GTPase domain, ankyrin repeat, and pleckstrin homology domain-containing protein 2 (AGAP2), and ADP-ribosylation factor 1 (ARF1), together with the HBV capsid, in the trans-Golgi network (TGN). This opens an alternative retrograde trafficking route for HBV from early endosomes (EEs) to the TGN and then to the endoplasmic reticulum (ER), thereby avoiding lysosomal degradation. DOCK11 also facilitates the association of cccDNA with H3K4me3 and RNA Pol II for activating cccDNA transcription. In addition, DOCK11 plays a crucial role in the host DNA repair system, being essential for cccDNA synthesis. This function can be inhibited by 10M-D42AN, a novel DOCK11-binding peptide, leading to the suppression of HBV replication both in vitro and in vivo. Treatment with a combination of 10M-D42AN and entecavir may represent a promising therapeutic strategy for patients with chronic hepatitis B (CHB). Consequently, DOCK11 may be seen as a potential candidate molecule in the development of molecularly targeted drugs against CHB.
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Affiliation(s)
- Ying-Yi Li
- Department of Gastroenterology, Kanazawa University Graduate School of Medicine, 13-1, Takaramachi, Kanazawa 920-8640, Japan
| | - Kazuhisa Murai
- Department of Clinical Laboratory Medicine, Kanazawa University Graduate School of Health Medicine, 13-1, Takaramachi, Kanazawa 920-8640, Japan
| | - Junyan Lyu
- Department of Clinical Laboratory Medicine, Kanazawa University Graduate School of Health Medicine, 13-1, Takaramachi, Kanazawa 920-8640, Japan
| | - Masao Honda
- Department of Gastroenterology, Kanazawa University Graduate School of Medicine, 13-1, Takaramachi, Kanazawa 920-8640, Japan
- Department of Clinical Laboratory Medicine, Kanazawa University Graduate School of Health Medicine, 13-1, Takaramachi, Kanazawa 920-8640, Japan
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Sun Y, Chen D, Dai T, Yu Z, Xie H, Wang X, Zhang W. Cell-free fat extract promotes axon regeneration and retinal ganglion cells survival in traumatic optic neuropathy. Front Cell Neurosci 2024; 18:1344853. [PMID: 38515790 PMCID: PMC10954833 DOI: 10.3389/fncel.2024.1344853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Accepted: 02/27/2024] [Indexed: 03/23/2024] Open
Abstract
Injuries to axons within the central nervous system (CNS) pose a substantial clinical challenge due to their limited regenerative capacity. This study investigates the therapeutic potential of Cell-free fat extract (CEFFE) in CNS injury. CEFFE was injected intravitreally after the optic nerve was crushed. Two weeks post-injury, quantification of regenerated axons and survival rates of retinal ganglion cells (RGCs) were performed. Subsequently, comprehensive gene ontology (GO) an-notation elucidated the cellular origins and functional attributes of CEFFE components. Molecular mechanisms underlying CEFFE's therapeutic effects were explored through Western blotting (WB). Additionally, levels of inflammatory factors within CEFFE were determined using enzyme-linked immunosorbent assay (ELISA), and histological staining of microglia was conducted to assess its impact on neuroinflammation. CEFFE demonstrated a significant capacity to promote axon re-generation and enhance RGCs survival. GO annotation revealed the involvement of 146 proteins within CEFFE in axonogenesis and neurogenesis. WB analysis unveiled the multifaceted pathways through which CEFFE exerts its therapeutic effects. Elevated levels of inflammatory factors were detected through ELISA, and CEFFE exhibited a modulatory effect on microglial activation in the retinal tissue following optic nerve crush (ONC). The present study highlights the therapeutic promise of CEFFE in the management of CNS injuries, exemplified by its ability to foster axon regeneration and improve RGCs survival.
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Affiliation(s)
- Yiyu Sun
- Department of Wound Reconstructive Surgery, Tongji Hospital Affiliated to Tongji University, School of Medicine, Tongji University, Shanghai, China
| | - Di Chen
- Department of Neurosurgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Tao Dai
- Department of Wound Reconstructive Surgery, Tongji Hospital Affiliated to Tongji University, School of Medicine, Tongji University, Shanghai, China
| | - Ziyou Yu
- Shanghai Key Laboratory of Tissue Engineering, Department of Plastic and Reconstructive Surgery, Shanghai 9th People’s Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Hui Xie
- Department of Geriatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Xiangsheng Wang
- Department of Plastic and Reconstructive Surgery, Affiliated Hangzhou First People’s Hospital, School of Medicine, Westlake University, Hangzhou, Zhejiang, China
| | - Wenjie Zhang
- Shanghai Key Laboratory of Tissue Engineering, Department of Plastic and Reconstructive Surgery, Shanghai 9th People’s Hospital, Shanghai Jiao Tong University, Shanghai, China
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Namekata K, Tsuji N, Guo X, Nishijima E, Honda S, Kitamura Y, Yamasaki A, Kishida M, Takeyama J, Ishikawa H, Shinozaki Y, Kimura A, Harada C, Harada T. Neuroprotection and axon regeneration by novel low-molecular-weight compounds through the modification of DOCK3 conformation. Cell Death Discov 2023; 9:166. [PMID: 37188749 PMCID: PMC10184973 DOI: 10.1038/s41420-023-01460-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 04/26/2023] [Accepted: 05/02/2023] [Indexed: 05/17/2023] Open
Abstract
Dedicator of cytokinesis 3 (DOCK3) is an atypical member of the guanine nucleotide exchange factors (GEFs) and plays important roles in neurite outgrowth. DOCK3 forms a complex with Engulfment and cell motility protein 1 (Elmo1) and effectively activates Rac1 and actin dynamics. In this study, we screened 462,169 low-molecular-weight compounds and identified the hit compounds that stimulate the interaction between DOCK3 and Elmo1, and neurite outgrowth in vitro. Some of the derivatives from the hit compound stimulated neuroprotection and axon regeneration in a mouse model of optic nerve injury. Our findings suggest that the low-molecular-weight DOCK3 activators could be a potential therapeutic candidate for treating axonal injury and neurodegenerative diseases including glaucoma.
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Affiliation(s)
- Kazuhiko Namekata
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Naoki Tsuji
- R&D Division, Daiichi Sankyo Co., Ltd, Tokyo, Japan
| | - Xiaoli Guo
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Euido Nishijima
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Sari Honda
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Yuta Kitamura
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | | | | | - Jun Takeyama
- Biological Research Department, Daiichi Sankyo RD Novare Co., Ltd, Tokyo, Japan
| | - Hirokazu Ishikawa
- Biological Research Department, Daiichi Sankyo RD Novare Co., Ltd, Tokyo, Japan
| | - Youichi Shinozaki
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Atsuko Kimura
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Chikako Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Takayuki Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.
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Zhou X, Hu J, Xu D, Zhang S, Wang Q. DOCK8 interference alleviates Aβ‑induced damage of BV2 cells by inhibiting STAT3/NLRP3/NF‑κB signaling. Exp Ther Med 2023; 25:134. [PMID: 36845964 PMCID: PMC9947585 DOI: 10.3892/etm.2023.11833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 01/17/2023] [Indexed: 02/12/2023] Open
Abstract
Dementia is defined as memory loss and other cognitive decline and it severely influences daily life. Alzheimer's disease (AD) is the most common cause of dementia. Dedicator of cytokinesis 8 (DOCK8) is reported to be involved in neurological diseases. The present study focused on investigating the role that DOCK8 serves in AD and addressing its hidden regulatory mechanism. Initially, Aβ1-42 (Aβ) was applied for the administration of BV2 cells. Subsequently, the mRNA and protein expression levels of DOCK8 were evaluated utilizing reverse transcription-quantitative PCR (RT-qPCR) and western blotting. After the DOCK8 silencing, immunofluorescence staining (IF), ELISA, wound healing and Transwell assays were applied to assess ionized calcium binding adapter molecule-1 (IBA-1) expression, release of inflammatory factors, migration and invasion in Aβ-induced BV2 cells. IF was used to evaluate cluster of differentiation (CD)11b expression. RT-qPCR and western blotting were to analyze the levels of M1 cell markers inducible nitric oxide synthase (iNOS) and CD86. The expression of STAT3/NLR family pyrin domain containing 3 (NLRP3)/NF-κB signaling-related proteins were determined by western blotting. Finally, the viability and apoptosis in hippocampal HT22 cells with DOCK8 depletion were estimated. Results revealed that Aβ induction greatly stimulated the expression levels of IBA-1 and DOCK8. DOCK8 silencing suppressed Aβ-induced inflammation, migration and invasion of BV2 cells. Additionally, DOCK8 deficiency conspicuously decreased the expression levels of CD11b, iNOS and CD86. The expression of phosphorylated (p-)STAT3, NLRP3, ASC, caspase1 and p-p65 was downregulated in Aβ-induced BV2 cells after DOCK8 depletion. STAT3 activator Colivelin reversed the effects of DOCK8 knockdown on IBA-1 expression, inflammation, migration, invasion and M1 cell polarization. In addition, the viability and apoptosis in hippocampal HT22 cells stimulated by neuroinflammatory release of BV2 cells were repressed following DOCK8 deletion. Collectively, DOCK8 interference alleviated Aβ-induced damage of BV2 cells by inhibiting STAT3/NLRP3/NF-κB signaling.
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Affiliation(s)
- Xueying Zhou
- Department of Psychiatry, Liyuan Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430077, P.R. China
| | - Ji Hu
- Department of Anesthesiology, Liyuan Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430077, P.R. China
| | - Deyi Xu
- Department of Psychiatry, Liyuan Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430077, P.R. China
| | - Sheng Zhang
- Department of Psychiatry, Liyuan Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430077, P.R. China
| | - Qianyan Wang
- Department of Cardiology, Liyuan Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430077, P.R. China,Correspondence to: Dr Qianyan Wang, Department of Cardiology, Liyuan Hospital of Tongji Medical College, Huazhong University of Science and Technology, 39 Lake Avenue, Wuchang, Wuhan, Hubei 430077, P.R. China
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Lin J, de Rezende VL, de Aguiar da Costa M, de Oliveira J, Gonçalves CL. Cholesterol metabolism pathway in autism spectrum disorder: From animal models to clinical observations. Pharmacol Biochem Behav 2023; 223:173522. [PMID: 36717034 DOI: 10.1016/j.pbb.2023.173522] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 12/18/2022] [Accepted: 01/24/2023] [Indexed: 01/29/2023]
Abstract
Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterized by a persistent impairment of social skills, including aspects of perception, interpretation, and response, combined with restricted and repetitive behavior. ASD is a complex and multifactorial condition, and its etiology could be attributed to genetic and environmental factors. Despite numerous clinical and experimental studies, no etiological factor, biomarker, and specific model of transmission have been consistently associated with ASD. However, an imbalance in cholesterol levels has been observed in many patients, more specifically, a condition of hypocholesterolemia, which seems to be shared between ASD and ASD-related genetic syndromes such as fragile X syndrome (FXS), Rett syndrome (RS), and Smith- Lemli-Opitz (SLO). Furthermore, it is known that alterations in cholesterol levels lead to neuroinflammation, oxidative stress, impaired myelination and synaptogenesis. Thus, the aim of this review is to discuss the cholesterol metabolic pathways in the ASD context, as well as in genetic syndromes related to ASD, through clinical observations and animal models. In fact, SLO, FXS, and RS patients display early behavioral markers of ASD followed by cholesterol disturbances. Several studies have demonstrated the role of cholesterol in psychiatric conditions and how its levels modulate brain neurodevelopment. This review suggests an important relationship between ASD pathology and cholesterol metabolism impairment; thus, some strategies could be raised - at clinical and pre-clinical levels - to explore whether cholesterol metabolism disturbance has a generally adverse effect in exacerbating the symptoms of ASD patients.
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Affiliation(s)
- Jaime Lin
- Laboratory of Experimental Neurology, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, SC, Brazil
| | - Victória Linden de Rezende
- Laboratory of Experimental Neurology, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, SC, Brazil
| | - Maiara de Aguiar da Costa
- Laboratory of Experimental Neurology, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, SC, Brazil
| | - Jade de Oliveira
- Laboratory for Research in Metabolic Disorders and Neurodegenerative Diseases, Graduate Program in Health Sciences, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil
| | - Cinara Ludvig Gonçalves
- Laboratory of Experimental Neurology, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, SC, Brazil.
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Axonal Regeneration: Underlying Molecular Mechanisms and Potential Therapeutic Targets. Biomedicines 2022; 10:biomedicines10123186. [PMID: 36551942 PMCID: PMC9775075 DOI: 10.3390/biomedicines10123186] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 11/21/2022] [Accepted: 12/01/2022] [Indexed: 12/13/2022] Open
Abstract
Axons in the peripheral nervous system have the ability to repair themselves after damage, whereas axons in the central nervous system are unable to do so. A common and important characteristic of damage to the spinal cord, brain, and peripheral nerves is the disruption of axonal regrowth. Interestingly, intrinsic growth factors play a significant role in the axonal regeneration of injured nerves. Various factors such as proteomic profile, microtubule stability, ribosomal location, and signalling pathways mark a line between the central and peripheral axons' capacity for self-renewal. Unfortunately, glial scar development, myelin-associated inhibitor molecules, lack of neurotrophic factors, and inflammatory reactions are among the factors that restrict axonal regeneration. Molecular pathways such as cAMP, MAPK, JAK/STAT, ATF3/CREB, BMP/SMAD, AKT/mTORC1/p70S6K, PI3K/AKT, GSK-3β/CLASP, BDNF/Trk, Ras/ERK, integrin/FAK, RhoA/ROCK/LIMK, and POSTN/integrin are activated after nerve injury and are considered significant players in axonal regeneration. In addition to the aforementioned pathways, growth factors, microRNAs, and astrocytes are also commendable participants in regeneration. In this review, we discuss the detailed mechanism of each pathway along with key players that can be potentially valuable targets to help achieve quick axonal healing. We also identify the prospective targets that could help close knowledge gaps in the molecular pathways underlying regeneration and shed light on the creation of more powerful strategies to encourage axonal regeneration after nervous system injury.
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Lu Y, Yu J, Dong Q, Du Y, Liang Z. DOCK4 as a Potential Biomarker Associated with Immune Infiltration in Stomach Adenocarcinoma: A Database Analysis. Int J Gen Med 2022; 15:6127-6143. [PMID: 35846794 PMCID: PMC9286484 DOI: 10.2147/ijgm.s357096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 06/29/2022] [Indexed: 12/24/2022] Open
Abstract
Purpose The involvement of dedicator for cytokinesis 4 (DOCK4), a guanine nucleotide exchange factor for Rac1, in immune infiltration in stomach adenocarcinoma (STAD) remains unclear. Methods The UALCAN database was used to analyze the expression of the DOCK family. The Kaplan–Meier method and Gene Expression Profiling Interactive Analysis (GEPIA) databases were used to assess the prognostic value of the DOCK family in STAD. Furthermore, the correlation between expression of DOCK4 as well as other immune-related marker genes and tumor immune infiltration in STAD was explored using the TIMER and GEPIA websites. Subsequently, the relationship between DOCK4 expression and clinical characteristics was verified using the UALCAN database. Finally, DOCK4 mutation was analyzed via the TIMER2.0 and cBioPortal databases and the DOCK4 protein-protein interaction networks were constructed using the GeneMANIA and STRING websites. Results DOCK4 was found to be a new prognostic biomarker in STAD. DOCK4 expression in tumors was thoroughly evaluated relative to paracancerous tissues; overexpression of DOCK4 had a negative impact on the prognosis of patients with STAD. DOCK4 was found to be significantly associated with tumor immune infiltration in STAD. Conclusion In summary, DOCK4 is a potential regulator of the recruitment and regulation of immune-infiltrating cells, thus serving as a valuable prognostic biomarker in STAD.
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Affiliation(s)
- Yi Lu
- Department of Otorhinolaryngology, Tianjin Medical University General Hospital, Tianjin, People's Republic of China
| | - Jiaxi Yu
- Department of Otorhinolaryngology, Tianjin Medical University General Hospital, Tianjin, People's Republic of China
| | - Qiuping Dong
- Department of Cancer Cell Biology, Tianjin's Key Laboratory of Cancer Prevention and Therapy, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, People's Republic of China
| | - Yan Du
- Department of Operating Theatre, Tianjin Medical University General Hospital, Tianjin, People's Republic of China
| | - Zheng Liang
- Department of Otorhinolaryngology, Tianjin Medical University General Hospital, Tianjin, People's Republic of China
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Peck AB, Nguyen CQ, Ambrus JL. A MZB Cell Activation Profile Present in the Lacrimal Glands of Sjögren's Syndrome-Susceptible C57BL/6.NOD- Aec1Aec2 Mice Defined by Global RNA Transcriptomic Analyses. Int J Mol Sci 2022; 23:6106. [PMID: 35682784 PMCID: PMC9181468 DOI: 10.3390/ijms23116106] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 05/25/2022] [Accepted: 05/26/2022] [Indexed: 02/01/2023] Open
Abstract
The C57BL/6.NOD-Aec1Aec2 mouse has been extensively studied to define the underlying cellular and molecular basis for the onset and development of Sjögren's syndrome (SS), a human systemic autoimmune disease characterized clinically as the loss of normal lacrimal and salivary gland functions leading respectively to dry eye and dry mouth pathologies. While an overwhelming majority of SS studies in both humans and rodent models have long focused primarily on pathophysiological events and the potential role of T lymphocytes in these events, recent studies in our murine models have indicated that marginal zone B (MZB) lymphocytes are critical for both development and onset of SS disease. Although migration and function of MZB cells are difficult to study in vivo and in vitro, we have carried out ex vivo investigations that use temporal global RNA transcriptomic analyses to track early cellular and molecular events in these exocrine glands of C57BL/6.NOD-Aec1Aec2 mice. In the present report, genome-wide transcriptome analyses of lacrimal glands indicate that genes and gene-sets temporally upregulated during early onset of disease define the Notch2/NF-kβ14 and Type1 interferon signal transduction pathways, as well as identify chemokines, especially Cxcl13, and Rho-GTPases, including DOCK molecules, in the cellular migration of immune cells to the lacrimal glands. We discuss how the current results compare with our recently published salivary gland data obtained from similar studies carried out in our C57BL/6.NOD-Aec1Aec2 mice, pointing out both similarities and differences in the etiopathogeneses underlying the autoimmune response within the two glands. Overall, this study uses the power of transcriptomic analyses to identify temporal molecular bioprocesses activated during the preclinical covert pathogenic stage(s) of SS disease and how these findings may impact future intervention therapies as the disease within the two exocrine glands may not be identical.
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Affiliation(s)
- Ammon B. Peck
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, P.O. Box 100125, Gainesville, FL 32610, USA; (C.Q.N.); (J.L.A.J.)
| | - Cuong Q. Nguyen
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, P.O. Box 100125, Gainesville, FL 32610, USA; (C.Q.N.); (J.L.A.J.)
| | - Julian L. Ambrus
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, P.O. Box 100125, Gainesville, FL 32610, USA; (C.Q.N.); (J.L.A.J.)
- Division of Allergy, Immunology and Rheumatology, SUNY Buffalo School of Medicine, 875 Ellicott Street, Buffalo, NY 14203, USA
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11
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Ravendran S, Hernández SS, König S, Bak RO. CRISPR/Cas-Based Gene Editing Strategies for DOCK8 Immunodeficiency Syndrome. Front Genome Ed 2022; 4:793010. [PMID: 35373187 PMCID: PMC8969908 DOI: 10.3389/fgeed.2022.793010] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 02/14/2022] [Indexed: 12/17/2022] Open
Abstract
Defects in the DOCK8 gene causes combined immunodeficiency termed DOCK8 immunodeficiency syndrome (DIDS). DIDS previously belonged to the disease category of autosomal recessive hyper IgE syndrome (AR-HIES) but is now classified as a combined immunodeficiency (CID). This genetic disorder induces early onset of susceptibility to severe recurrent viral and bacterial infections, atopic diseases and malignancy resulting in high morbidity and mortality. This pathological state arises from impairment of actin polymerization and cytoskeletal rearrangement, which induces improper immune cell migration-, survival-, and effector functions. Owing to the severity of the disease, early allogenic hematopoietic stem cell transplantation is recommended even though it is associated with risk of unintended adverse effects, the need for compatible donors, and high expenses. So far, no alternative therapies have been developed, but the monogenic recessive nature of the disease suggests that gene therapy may be applied. The advent of the CRISPR/Cas gene editing system heralds a new era of possibilities in precision gene therapy, and positive results from clinical trials have already suggested that the tool may provide definitive cures for several genetic disorders. Here, we discuss the potential application of different CRISPR/Cas-mediated genetic therapies to correct the DOCK8 gene. Our findings encourage the pursuit of CRISPR/Cas-based gene editing approaches, which may constitute more precise, affordable, and low-risk definitive treatment options for DOCK8 deficiency.
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Affiliation(s)
| | | | | | - Rasmus O. Bak
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
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12
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Qin T, Yang J, Huang D, Zhang Z, Huang Y, Chen H, Xu G. DOCK4 stimulates MUC2 production through its effect on goblet cell differentiation. J Cell Physiol 2021; 236:6507-6519. [PMID: 33559155 DOI: 10.1002/jcp.30325] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 01/28/2021] [Accepted: 02/01/2021] [Indexed: 01/13/2023]
Abstract
The intestinal mucosa is in continuous contact with milliard of microorganisms, thus intestinal epithelial barrier is a critical component in the arsenal of defense mechanisms required to prevent infection and inflammation. Mucin 2 (MUC2), which is produced by the goblet cells, forms the skeleton of the intestinal mucus and protects the intestinal tract from self-digestion and numerous microorganisms. Dedicator of cytokinesis 4 (DOCK4) is a member of the DOCK-B subfamily of the DOCK family of guanine nucleotide exchange factors. It is reported that DOCK4 plays a critical role in the repair of the barrier function of the intestinal epithelium after chemical damage. In this study, the role of DOCK4 in the goblet cell differentiation and MUC2 production is explored. Disordered intestinal epithelium and shortage of goblet cells were observed in DOCK4 gene knockout mice. Furthermore, DOCK4 deletion contributed to the low expression of MUC2 and the goblet cell differentiation/maturation factors including growth factor independent 1 (Gfi1) and SAM pointed domain epithelial-specific transcription factor (Spdef) in mouse ileums and colons. Overexpression of DOCK4 caused a marked increase in Gfi1, Spdef, and MUC2, while siRNA knockdown of endogenous DOCK4 significantly decreased Gfi1, Spdef, and MUC2 in HT-29 cells. In addition, MUC2, DOCK4, and the goblet cell differentiation/maturation factors mRNA levels were decreased in colorectal cancer samples compared with normal colons. A significant positive correlation was found between MUC2 and DOCK4. In conclusion, DOCK4 may serve as a critical regulator of goblet cell differentiation and MUC2 production in the intestine.
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Affiliation(s)
- Tingfeng Qin
- Department of Physiology, School of Medicine, Jinan University, Tianhe, Guangzhou, Guangdong, China
| | - Jie Yang
- Department of Physiology, School of Medicine, Jinan University, Tianhe, Guangzhou, Guangdong, China
| | - Dayin Huang
- Department of Physiology, School of Medicine, Jinan University, Tianhe, Guangzhou, Guangdong, China
| | - Zhijun Zhang
- Department of Physiology, School of Medicine, Jinan University, Tianhe, Guangzhou, Guangdong, China
| | - Yanling Huang
- Department of Physiology, School of Medicine, Jinan University, Tianhe, Guangzhou, Guangdong, China
| | - Hui Chen
- Cell-Gene Therapy Translational Medicine Research Center, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Geyang Xu
- Department of Physiology, School of Medicine, Jinan University, Tianhe, Guangzhou, Guangdong, China
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13
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Xie Y, Chen J, Wu B, He T, Xie L, Liu Z. Dock2 affects the host susceptibility to Citrobacter rodentium infection through regulating gut microbiota. Gut Pathog 2021; 13:52. [PMID: 34391464 PMCID: PMC8364044 DOI: 10.1186/s13099-021-00449-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 08/04/2021] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Dysregulated gut microbiota is one of major pathogenic factors in the development of colitis. Dock2 acts as a guanine nucleotide exchange factor (GEF) and activates small G protein RAC1. Our previous study showed that, compared to wild type (WT) mice, Dock2-/- mice were more susceptible to colitis induced by Citrobacter rodentium infection. However, it is not clear whether gut microbiota affects the host susceptibility to enteric bacterial infection in Dock2-/- mice. RESULTS In this study, we demonstrated that Dock2 regulated the gut microbiota and affected the host susceptibility to C. rodentium infection by co-housing, fecal microbiota transfer and antibiotic treatment methods. Microbiota analysis by 16 S rRNA gene sequencing showed that Dock2 increased the abundance of prevotellaceae-NK3B31-group and Lactobacillus but decreased that of Helicobacter. CONCLUSIONS These results suggest that Dock2 regulates the composition of gut microbiota and affects the host susceptibility to C. rodentium infection.
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Affiliation(s)
- Yuan Xie
- Department of Nephrology, The First People's Hospital of Nankang District, Ganzhou, Jiangxi, China.,Gannan Medical University, Ganzhou, Jiangxi, China
| | - Jun Chen
- Gannan Medical University, Ganzhou, Jiangxi, China
| | - Bing Wu
- School of Basic Medicine, Gannan Medical University, Jiangxi, Ganzhou, China
| | - Tiansheng He
- School of Basic Medicine, Gannan Medical University, Jiangxi, Ganzhou, China
| | - Lu Xie
- School of Basic Medicine, Gannan Medical University, Jiangxi, Ganzhou, China
| | - Zhiping Liu
- School of Basic Medicine, Gannan Medical University, Jiangxi, Ganzhou, China. .,Center for Immunology, Key Laboratory of Prevention and Treatment of Cardiovascular and Cerebrovascular Diseases, Ministry of Education, Gannan Medical University, Jiangxi, Ganzhou, China.
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14
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Peck AB, Nguyen CQ, Ambrus JL. Upregulated Chemokine and Rho-GTPase Genes Define Immune Cell Emigration into Salivary Glands of Sjögren's Syndrome-Susceptible C57BL/6.NOD- Aec1Aec2 Mice. Int J Mol Sci 2021; 22:7176. [PMID: 34281229 PMCID: PMC8267620 DOI: 10.3390/ijms22137176] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Revised: 06/16/2021] [Accepted: 06/17/2021] [Indexed: 02/06/2023] Open
Abstract
The C57BL/6.NOD-Aec1Aec2 mouse is considered a highly appropriate model of Sjögren's Syndrome (SS), a human systemic autoimmune disease characterized primarily as the loss of lacrimal and salivary gland functions. This mouse model, as well as other mouse models of SS, have shown that B lymphocytes are essential for the development and onset of observed clinical manifestations. More recently, studies carried out in the C57BL/6.IL14α transgenic mouse have indicated that the marginal zone B (MZB) cell population is responsible for development of SS disease, reflecting recent observations that MZB cells are present in the salivary glands of SS patients and most likely initiate the subsequent loss of exocrine functions. Although MZB cells are difficult to study in vivo and in vitro, we have carried out an ex vivo investigation that uses temporal global RNA transcriptomic analyses to profile differentially expressed genes known to be associated with cell migration. Results indicate a temporal upregulation of specific chemokine, chemokine receptor, and Rho-GTPase genes in the salivary glands of C57BL/6.NOD-Aec1Aec2 mice that correlate with the early appearance of periductal lymphocyte infiltrations. Using the power of transcriptomic analyses to better define the genetic profile of lymphocytic emigration into the salivary glands of SS mice, new insights into the underlying mechanisms of SS disease development and onset begin to come into focus, thereby establishing a foundation for further in-depth and novel investigations of the covert and early overt phases of SS disease at the cellular level.
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Affiliation(s)
- Ammon B. Peck
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, P.O. Box 100125, Gainesville, FL 32610, USA;
| | - Cuong Q. Nguyen
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, P.O. Box 100125, Gainesville, FL 32610, USA;
| | - Julian L. Ambrus
- Division of Allergy, Immunology and Rheumatology, SUNY Buffalo School of Medicine, 875 Ellicott Street, Buffalo, NY 14203, USA;
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15
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Thompson AP, Bitsina C, Gray JL, von Delft F, Brennan PE. RHO to the DOCK for GDP disembarking: Structural insights into the DOCK GTPase nucleotide exchange factors. J Biol Chem 2021; 296:100521. [PMID: 33684443 PMCID: PMC8063744 DOI: 10.1016/j.jbc.2021.100521] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 03/04/2021] [Accepted: 03/04/2021] [Indexed: 01/16/2023] Open
Abstract
The human dedicator of cytokinesis (DOCK) family consists of 11 structurally conserved proteins that serve as atypical RHO guanine nucleotide exchange factors (RHO GEFs). These regulatory proteins act as mediators in numerous cellular cascades that promote cytoskeletal remodeling, playing roles in various crucial processes such as differentiation, migration, polarization, and axon growth in neurons. At the molecular level, DOCK DHR2 domains facilitate nucleotide dissociation from small GTPases, a process that is otherwise too slow for rapid spatiotemporal control of cellular signaling. Here, we provide an overview of the biological and structural characteristics for the various DOCK proteins and describe how they differ from other RHO GEFs and between DOCK subfamilies. The expression of the family varies depending on cell or tissue type, and they are consequently implicated in a broad range of disease phenotypes, particularly in the brain. A growing body of available structural information reveals the mechanism by which the catalytic DHR2 domain elicits nucleotide dissociation and also indicates strategies for the discovery and design of high-affinity small-molecule inhibitors. Such compounds could serve as chemical probes to interrogate the cellular function and provide starting points for drug discovery of this important class of enzymes.
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Affiliation(s)
- Andrew P Thompson
- Nuffield Department of Medicine, Alzheimer's Research UK Oxford Drug Discovery Institute, University of Oxford, Oxford, United Kingdom; Nuffield Department of Medicine, Target Discovery Institute, University of Oxford, Oxford, United Kingdom; Nuffield Department of Medicine, Centre for Medicines Discovery, University of Oxford, Oxford, United Kingdom
| | - Christina Bitsina
- Nuffield Department of Medicine, Alzheimer's Research UK Oxford Drug Discovery Institute, University of Oxford, Oxford, United Kingdom; Nuffield Department of Medicine, Target Discovery Institute, University of Oxford, Oxford, United Kingdom; Nuffield Department of Medicine, Centre for Medicines Discovery, University of Oxford, Oxford, United Kingdom
| | - Janine L Gray
- Nuffield Department of Medicine, Alzheimer's Research UK Oxford Drug Discovery Institute, University of Oxford, Oxford, United Kingdom; Nuffield Department of Medicine, Target Discovery Institute, University of Oxford, Oxford, United Kingdom; Nuffield Department of Medicine, Centre for Medicines Discovery, University of Oxford, Oxford, United Kingdom
| | - Frank von Delft
- Nuffield Department of Medicine, Alzheimer's Research UK Oxford Drug Discovery Institute, University of Oxford, Oxford, United Kingdom; Nuffield Department of Medicine, Centre for Medicines Discovery, University of Oxford, Oxford, United Kingdom; Diamond Light Source, Harwell Science and Innovation Campus, Didcot, United Kingdom; Department of Biochemistry, University of Johannesburg, Auckland Park, South Africa
| | - Paul E Brennan
- Nuffield Department of Medicine, Alzheimer's Research UK Oxford Drug Discovery Institute, University of Oxford, Oxford, United Kingdom; Nuffield Department of Medicine, Target Discovery Institute, University of Oxford, Oxford, United Kingdom; Nuffield Department of Medicine, Centre for Medicines Discovery, University of Oxford, Oxford, United Kingdom.
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16
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Topical ripasudil stimulates neuroprotection and axon regeneration in adult mice following optic nerve injury. Sci Rep 2020; 10:15709. [PMID: 32973242 PMCID: PMC7515881 DOI: 10.1038/s41598-020-72748-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 09/04/2020] [Indexed: 11/24/2022] Open
Abstract
Optic nerve injury induces optic nerve degeneration and retinal ganglion cell (RGC) death that lead to visual disturbance. In this study, we examined if topical ripasudil has therapeutic potential in adult mice after optic nerve crush (ONC). Topical ripasudil suppressed ONC-induced phosphorylation of p38 mitogen-activated protein kinase and ameliorated RGC death. In addition, topical ripasudil significantly suppressed the phosphorylation of collapsin response mediator protein 2 and cofilin, and promoted optic nerve regeneration. These results suggest that topical ripasudil promotes RGC protection and optic nerve regeneration by modulating multiple signaling pathways associated with neural cell death, microtubule assembly and actin polymerization.
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17
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Zhang W, Zheng X, Xie S, Zhang S, Mao J, Cai Y, Lu X, Chen W, Ni H, Xie L. TBOPP enhances the anticancer effect of cisplatin by inhibiting DOCK1 in renal cell carcinoma. Mol Med Rep 2020; 22:1187-1194. [PMID: 32626999 PMCID: PMC7339706 DOI: 10.3892/mmr.2020.11243] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 04/15/2020] [Indexed: 02/06/2023] Open
Abstract
The treatment of renal cell carcinoma (RCC) with chemotherapy remains a challenge; therefore, improving the knowledge of the molecular mechanisms underlying RCC chemoresistance and developing novel therapeutic strategies is important. Dedicator of cytokinesis 1 (DOCK1), the first member of the DOCK family to be discovered, displays various roles during tumorigenesis; however, its role during RCC progression is not completely understood. Therefore, the present study aimed to clarify the function of DOCK1 and 1-[2-(3′-(trifluoromethyl)-(1,1′-biphenyl)-4-yl)-2-oxoethyl]-5-pyrrolidinylsulfonyl-2 (1H)-pyridone (TBOPP), a DOCK1-sensitive inhibitor, during RCC development and chemoresistance. The results of CCK-8 and EdU assay indicated that TBOPP decreased RCC cell viability and proliferation compared with the control group, and sensitized RCC cells to cisplatin. Moreover, RCC cells with high DOCK1 expression levels displayed increased resistance to cisplatin, whereas DOCK1 knockdown enhanced the lethal effects of cisplatin on RCC cells. Furthermore, the results determined by western blotting, CCK-8 and cell apoptosis assay indicated that TBOPP effectively reduced DOCK1 expression levels compared with the control group, and the TBOPP-mediated cisplatin sensitizing effect was mediated by DOCK1 inhibition. The present study suggests that DOCK1 plays a vital role in RCC cell chemoresistance to cisplatin; therefore, TBOPP may serve as a novel therapeutic agent for RCC chemoresistance.
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Affiliation(s)
- Wei Zhang
- Department of Urology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310009, P.R. China
| | - Xiaoxiao Zheng
- Department of Medical Oncology, Tongde Hospital of Zhejiang Province, Hangzhou, Zhejiang 310012, P.R. China
| | - Shangzhi Xie
- Department of Medical Oncology, Tongde Hospital of Zhejiang Province, Hangzhou, Zhejiang 310012, P.R. China
| | - Shufen Zhang
- Department of Medical Oncology, Tongde Hospital of Zhejiang Province, Hangzhou, Zhejiang 310012, P.R. China
| | - Jiayan Mao
- Department of Medical Oncology, Tongde Hospital of Zhejiang Province, Hangzhou, Zhejiang 310012, P.R. China
| | - Ying Cai
- Department of Medical Oncology, Tongde Hospital of Zhejiang Province, Hangzhou, Zhejiang 310012, P.R. China
| | - Xuemei Lu
- Department of Medical Oncology, Tongde Hospital of Zhejiang Province, Hangzhou, Zhejiang 310012, P.R. China
| | - Wei Chen
- Department of Medical Oncology, Tongde Hospital of Zhejiang Province, Hangzhou, Zhejiang 310012, P.R. China
| | - Haibin Ni
- Department of General Surgery, Tongde Hospital of Zhejiang Province, Hangzhou, Zhejiang 310012, P.R. China
| | - Liping Xie
- Department of Urology, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310009, P.R. China
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18
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Namekata K, Guo X, Kimura A, Azuchi Y, Kitamura Y, Harada C, Harada T. Roles of the DOCK-D family proteins in a mouse model of neuroinflammation. J Biol Chem 2020; 295:6710-6720. [PMID: 32241915 DOI: 10.1074/jbc.ra119.010438] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 03/16/2020] [Indexed: 02/01/2023] Open
Abstract
The DOCK-D (dedicator of cytokinesis D) family proteins are atypical guanine nucleotide exchange factors that regulate Rho GTPase activity. The family consists of Zizimin1 (DOCK9), Zizimin2 (DOCK11), and Zizimin3 (DOCK10). Functions of the DOCK-D family proteins are presently not well-explored, and the role of the DOCK-D family in neuroinflammation is unknown. In this study, we generated three mouse lines in which DOCK9 (DOCK9 -/-), DOCK10 (DOCK10 -/-), or DOCK11 (DOCK11 -/-) had been deleted and examined the phenotypic effects of these gene deletions in MOG35-55 peptide-induced experimental autoimmune encephalomyelitis, an animal model of the neuroinflammatory disorder multiple sclerosis. We found that all the gene knockout lines were healthy and viable. The only phenotype observed under normal conditions was a slightly smaller proportion of B cells in splenocytes in DOCK10 -/- mice than in the other mouse lines. We also found that the migration ability of macrophages is impaired in DOCK10 -/- and DOCK11 -/- mice and that the severity of experimental autoimmune encephalomyelitis was ameliorated only in DOCK10 -/- mice. No apparent phenotype was observed for DOCK9 -/- mice. Further investigations indicated that lipopolysaccharide stimulation up-regulates DOCK10 expression in microglia and that microglial migration is decreased in DOCK10 -/- mice. Up-regulation of C-C motif chemokine ligand 2 (CCL2) expression induced by activation of Toll-like receptor 4 or 9 signaling was reduced in DOCK10 -/- astrocytes compared with WT astrocytes. Taken together, our findings suggest that DOCK10 plays a role in innate immunity and neuroinflammation and might represent a potential therapeutic target for managing multiple sclerosis.
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Affiliation(s)
- Kazuhiko Namekata
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Xiaoli Guo
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Atsuko Kimura
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Yuriko Azuchi
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Yuta Kitamura
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Chikako Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Takayuki Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
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19
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Rho GTPase Regulators and Effectors in Autism Spectrum Disorders: Animal Models and Insights for Therapeutics. Cells 2020; 9:cells9040835. [PMID: 32244264 PMCID: PMC7226772 DOI: 10.3390/cells9040835] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 03/22/2020] [Accepted: 03/26/2020] [Indexed: 12/18/2022] Open
Abstract
The Rho family GTPases are small G proteins that act as molecular switches shuttling between active and inactive forms. Rho GTPases are regulated by two classes of regulatory proteins, guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs). Rho GTPases transduce the upstream signals to downstream effectors, thus regulating diverse cellular processes, such as growth, migration, adhesion, and differentiation. In particular, Rho GTPases play essential roles in regulating neuronal morphology and function. Recent evidence suggests that dysfunction of Rho GTPase signaling contributes substantially to the pathogenesis of autism spectrum disorder (ASD). It has been found that 20 genes encoding Rho GTPase regulators and effectors are listed as ASD risk genes by Simons foundation autism research initiative (SFARI). This review summarizes the clinical evidence, protein structure, and protein expression pattern of these 20 genes. Moreover, ASD-related behavioral phenotypes in animal models of these genes are reviewed, and the therapeutic approaches that show successful treatment effects in these animal models are discussed.
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20
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Namekata K, Guo X, Kimura A, Arai N, Harada C, Harada T. DOCK8 is expressed in microglia, and it regulates microglial activity during neurodegeneration in murine disease models. J Biol Chem 2019; 294:13421-13433. [PMID: 31337702 DOI: 10.1074/jbc.ra119.007645] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 06/25/2019] [Indexed: 12/15/2022] Open
Abstract
Dedicator of cytokinesis 8 (DOCK8) is a guanine nucleotide exchange factor whose loss of function results in immunodeficiency, but its role in the central nervous system (CNS) has been unclear. Microglia are the resident immune cells of the CNS and are implicated in the pathogenesis of various neurodegenerative diseases, including multiple sclerosis (MS) and glaucoma, which affects the visual system. However, the exact roles of microglia in these diseases remain unknown. Herein, we report that DOCK8 is expressed in microglia but not in neurons or astrocytes and that its expression is increased during neuroinflammation. To define the role of DOCK8 in microglial activity, we focused on the retina, a tissue devoid of infiltrating T cells. The retina is divided into distinct layers, and in a disease model of MS/optic neuritis, DOCK8-deficient mice exhibited a clear reduction in microglial migration through these layers. Moreover, neuroinflammation severity, indicated by clinical scores, visual function, and retinal ganglion cell (RGC) death, was reduced in the DOCK8-deficient mice. Furthermore, using a glaucoma disease model, we observed impaired microglial phagocytosis of RGCs in DOCK8-deficient mice. Our data demonstrate that DOCK8 is expressed in microglia and regulates microglial activity in disease states. These findings contribute to a better understanding of the molecular pathways involved in microglial activation and implicate a role of DOCK8 in several neurological diseases.
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Affiliation(s)
- Kazuhiko Namekata
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Xiaoli Guo
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Atsuko Kimura
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Nobutaka Arai
- Brain Pathology Research Center, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Chikako Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Takayuki Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan.
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21
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Vroemen PAMM, Gorgels TGMF, Webers CAB, de Boer J. Modeling the Mechanical Parameters of Glaucoma. TISSUE ENGINEERING PART B-REVIEWS 2019; 25:412-428. [PMID: 31088331 DOI: 10.1089/ten.teb.2019.0044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Glaucoma is a major eye disease characterized by a progressive loss of retinal ganglion cells (RGCs). Biomechanical forces as a result of hydrostatic pressure and strain play a role in this disease. Decreasing intraocular pressure is the only available therapy so far, but is not always effective and does not prevent blindness in many cases. There is a need for drugs that protect RGCs from dying in glaucoma; to develop these, we need valid glaucoma and drug screening models. Since in vivo models are unsuitable for screening purposes, we focus on in vitro and ex vivo models in this review. Many groups have studied pressure and strain model systems to mimic glaucoma, to investigate the molecular and cellular events leading to mechanically induced RGC death. Therefore, the focus of this review is on the different mechanical model systems used to mimic the biomechanical forces in glaucoma. Most models use either cell or tissue strain, or fluid- or gas-controlled hydrostatic pressure application and apply it to the relevant cell types such as trabecular meshwork cells, optic nerve head astrocytes, and RGCs, but also to entire eyes. New model systems are warranted to study concepts and test experimental compounds for the development of new drugs to protect vision in glaucoma patients. Impact Statement The outcome of currently developed models to investigate mechanically induced retinal ganglion cell death by applying different mechanical strains varies widely. This suggests that a robust glaucoma model has not been developed yet. However, a comprehensive overview of current developments is not available. In this review, we have therefore assessed what has been done before and summarized the available knowledge in the field, which can be used to develop improved models for glaucoma research.
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Affiliation(s)
- Pascal A M M Vroemen
- University Eye Clinic Maastricht UMC+, Maastricht University Medical Centre+, Maastricht, The Netherlands.,Department of Complex Tissue Regeneration (CTR), MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Maastricht, The Netherlands.,Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Theo G M F Gorgels
- University Eye Clinic Maastricht UMC+, Maastricht University Medical Centre+, Maastricht, The Netherlands.,Netherlands Institute for Neuroscience, Amsterdam, The Netherlands
| | - Carroll A B Webers
- University Eye Clinic Maastricht UMC+, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Jan de Boer
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.,Institute for Complex Molecular Structures, Eindhoven University of Technology, Eindhoven, The Netherlands
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22
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Wiltrout K, Ferrer A, van de Laar I, Namekata K, Harada T, Klee EW, Zimmerman MT, Cousin MA, Kempainen JL, Babovic-Vuksanovic D, van Slegtenhorst MA, Aarts-Tesselaar CD, Schnur RE, Andrews M, Shinawi M. Variants in DOCK3 cause developmental delay and hypotonia. Eur J Hum Genet 2019; 27:1225-1234. [PMID: 30976111 DOI: 10.1038/s41431-019-0397-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 03/13/2019] [Accepted: 03/26/2019] [Indexed: 01/05/2023] Open
Abstract
The DOCK3 gene encodes the Dedicator of cytokinesis 3 (DOCK3) protein, which belongs to the family of guanine nucleotide exchange factors and is expressed almost exclusively in the brain and spinal cord. We used whole exome sequencing (WES) to investigate the molecular cause of developmental delay and hypotonia in three unrelated probands. WES identified truncating and splice site variants in Patient 1 and compound heterozygous and homozygous missense variants in Patients 2 and 3, respectively. We studied the effect of the three missense variants in vitro by using site-directed mutagenesis and pull-down assay and show that the induction of Rac1 activation was significantly lower in DOCK3 mutant cells compared with wild type human DOCK3 (P < 0.05). We generated a protein model to further examine the effect of the two missense variants within or adjacent to the DHR-2 domain in DOCK3 and this model supports pathogenicity. Our results support a loss of function mechanism but the data on the patients with missense variants should be cautiously interpreted because of the variability of the phenotypes and limited number of cases. Prior studies have described DOCK3 bi-allelic loss of function variants in two families with ataxia, hypotonia, and developmental delay. Here, we report on three patients with DOCK3-related developmental delay, wide-based or uncoordinated gait, and hypotonia, further supporting DOCK3's role in a neurodevelopmental syndrome and expanding the spectrum of phenotypic and genotypic variability.
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Affiliation(s)
- Kimberly Wiltrout
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA
| | - Alejandro Ferrer
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA
| | - Ingrid van de Laar
- Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Kazuhiko Namekata
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Takayuki Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Eric W Klee
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA
| | - Michael T Zimmerman
- Genomics Sciences & Precision Medicine Center, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Margot A Cousin
- Center for Individualized Medicine, Mayo Clinic, Rochester, MN, USA
| | | | | | | | | | | | - Marisa Andrews
- Division of Genetics and Genomic Medicine, Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, USA
| | - Marwan Shinawi
- Division of Genetics and Genomic Medicine, Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, USA.
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23
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Niftullayev S, Lamarche-Vane N. Regulators of Rho GTPases in the Nervous System: Molecular Implication in Axon Guidance and Neurological Disorders. Int J Mol Sci 2019; 20:E1497. [PMID: 30934641 PMCID: PMC6471118 DOI: 10.3390/ijms20061497] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 03/18/2019] [Indexed: 12/11/2022] Open
Abstract
One of the fundamental steps during development of the nervous system is the formation of proper connections between neurons and their target cells-a process called neural wiring, failure of which causes neurological disorders ranging from autism to Down's syndrome. Axons navigate through the complex environment of a developing embryo toward their targets, which can be far away from their cell bodies. Successful implementation of neuronal wiring, which is crucial for fulfillment of all behavioral functions, is achieved through an intimate interplay between axon guidance and neural activity. In this review, our focus will be on axon pathfinding and the implication of some of its downstream molecular components in neurological disorders. More precisely, we will talk about axon guidance and the molecules implicated in this process. After, we will briefly review the Rho family of small GTPases, their regulators, and their involvement in downstream signaling pathways of the axon guidance cues/receptor complexes. We will then proceed to the final and main part of this review, where we will thoroughly comment on the implication of the regulators for Rho GTPases-GEFs (Guanine nucleotide Exchange Factors) and GAPs (GTPase-activating Proteins)-in neurological diseases and disorders.
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Affiliation(s)
- Sadig Niftullayev
- Cancer Research Program, Research Institute of the MUHC, Montreal, QC H4A 3J1, Canada.
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC H3A 2B2, Canada.
| | - Nathalie Lamarche-Vane
- Cancer Research Program, Research Institute of the MUHC, Montreal, QC H4A 3J1, Canada.
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC H3A 2B2, Canada.
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24
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Kang N, Liu J, Zhao Y. Dissociation mechanism of GDP from Cdc42 via DOCK9 revealed by molecular dynamics simulations. Proteins 2019; 87:433-442. [PMID: 30714195 DOI: 10.1002/prot.25665] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 01/28/2019] [Accepted: 01/31/2019] [Indexed: 12/18/2022]
Abstract
Cell division control protein 42 homolog (Cdc42) influences a variety of cellular responses such as cell migration and polarity. Deregulation of Cdc42 has been associated with several human diseases and developmental disorders. Over-activation of Cdc42 through guanine nucleotide exchange factor (GEF) is a critical event for Cdc42 involved cancer metastasis. Members of DOCK family of GEF are important activators of Cdc42. However, this activation mechanism is still unknown. Molecular dynamics (MD) simulations and molecular mechanics-Poisson-Boltzmann surface area (MM-PBSA) calculations were employed to investigate the central step of the activation of Cdc42: the dissociation mechanism of GDP from Cdc42 via DOCK9. Simulation results show that Mg2+ ion has a remarkable influence on the conformational change of switch I of Cdc42 through residue Pro34 which functions as a "clasp" to control the flexibility of switch I. In the GDP dissociation process, the Mg2+ ion leave first to result in a suitable conformation of Cdc42 for following DOCK9 binding to. When DOCK9 binds to Cdc42, it changes the orientations of residues Lys16, Thr17, Cys18 and Phe28 of Cdc42 to weaken the interactions between Cdc42 and GDP to release GDP. This study first elucidates the dissociation mechanism of GDP from Cdc42 via DOCK9 and identifies the essential residues of Cdc42 in this process. These simulation results are consistent with the recent findings of biochemical and amino acid mutational studies, and the observations are beneficial to understand the activation mechanism of Cdc42 and to provide insights for designing compounds targeting on Cdc42 related cancer metastasis.
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Affiliation(s)
- Ning Kang
- School of Pharmacy, Shanghai Jiao Tong University, Shanghai, China
| | - Jiansheng Liu
- Department of Neurology, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yaxue Zhao
- School of Pharmacy, Shanghai Jiao Tong University, Shanghai, China
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25
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Harada C, Kimura A, Guo X, Namekata K, Harada T. Recent advances in genetically modified animal models of glaucoma and their roles in drug repositioning. Br J Ophthalmol 2018; 103:161-166. [PMID: 30366949 PMCID: PMC6362806 DOI: 10.1136/bjophthalmol-2018-312724] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 08/21/2018] [Accepted: 08/25/2018] [Indexed: 12/18/2022]
Abstract
Glaucoma is one of the leading causes of vision loss in the world. Currently, pharmacological intervention for glaucoma therapy is limited to eye drops that reduce intraocular pressure (IOP). Recent studies have shown that various factors as well as IOP are involved in the pathogenesis of glaucoma, especially in the subtype of normal tension glaucoma. To date, various animal models of glaucoma have been established, including glutamate/aspartate transporter knockout (KO) mice, excitatory amino acid carrier 1 KO mice, optineurin E50K knock-in mice, DBA/2J mice and experimentally induced models. These animal models are very useful for elucidating the pathogenesis of glaucoma and for identifying potential therapeutic targets. However, each model represents only some aspects of glaucoma, never the whole disease. This review will summarise the benefits and limitations of using disease models of glaucoma and recent basic research in retinal protection using existing drugs.
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Affiliation(s)
- Chikako Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Atsuko Kimura
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Xiaoli Guo
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Kazuhiko Namekata
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Takayuki Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
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26
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Liu C, Guo T, Xu G, Sakai A, Ren S, Fukusumi T, Ando M, Sadat S, Saito Y, Khan Z, Fisch KM, Califano J. Characterization of Alternative Splicing Events in HPV-Negative Head and Neck Squamous Cell Carcinoma Identifies an Oncogenic DOCK5 Variant. Clin Cancer Res 2018; 24:5123-5132. [PMID: 29945995 DOI: 10.1158/1078-0432.ccr-18-0752] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 05/29/2018] [Accepted: 06/22/2018] [Indexed: 01/26/2023]
Abstract
Purpose: Head and neck squamous cell carcinoma (HNSCC) is one of the most common cancers worldwide, and alternative splicing is considered to play important roles in tumor progression. Our study is designed to identify alternative splicing events (ASEs) in human papillomavirus (HPV)-negative HNSCC.Experimental Design: RNA sequencing data of 407 HPV-negative HNSCC and 38 normal samples were obtained from The Cancer Genome Atlas (TCGA), and splice junctions were discovered using MapSplice. Outlier analysis was used to identify significant splicing junctions between HPV-negative HNSCC and normal samples. To explore the functional role of the identified DOCK5 variant, we checked its expression with qRT-PCR in a separate primary tumor validation set and performed proliferation, migration, and invasion assays.Results: A total of 580 significant splicing events were identified in HPV-negative HNSCC, and the most common type of splicing events was an alternative start site (33.3%). The prevalence of a given individual ASE among the tumor cohort ranged from 9.8% and 64.4%. Within the 407 HPV-negative HNSCC samples in TCGA, the number of significant ASEs differentially expressed in each tumor ranged from 17 to 290. We identified a novel candidate oncogenic DOCK5 variant confirmed using qRT-PCR in a separate primary tumor validation set. Loss- and gain-of-function experiments indicated that DOCK5 variant promoted proliferation, migration, and invasion of HPV-negative HNSCC cells, and patients with higher expression of DOCK5 variant showed decreased overall survival.Conclusions: Analysis of ASEs in HPV-negative HNSCC identifies multiple alterations likely related to carcinogenesis, including an oncogenic DOCK5 variant. Clin Cancer Res; 24(20); 5123-32. ©2018 AACR.
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Affiliation(s)
- Chao Liu
- Moores Cancer Center, University of California San Diego, San Diego, California.,Department of Otolaryngology - Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Theresa Guo
- Department of Otolaryngology - Head and Neck Surgery, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Guorong Xu
- Center for Computational Biology and Bioinformatics, Department of Medicine, University of California San Diego, San Diego, California
| | - Akihiro Sakai
- Moores Cancer Center, University of California San Diego, San Diego, California
| | - Shuling Ren
- Moores Cancer Center, University of California San Diego, San Diego, California.,Department of Otolaryngology - Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Takahito Fukusumi
- Moores Cancer Center, University of California San Diego, San Diego, California
| | - Mizuo Ando
- Moores Cancer Center, University of California San Diego, San Diego, California
| | - Sayed Sadat
- Moores Cancer Center, University of California San Diego, San Diego, California
| | - Yuki Saito
- Moores Cancer Center, University of California San Diego, San Diego, California
| | - Zubair Khan
- Department of Otolaryngology - Head and Neck Surgery, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Kathleen M Fisch
- Center for Computational Biology and Bioinformatics, Department of Medicine, University of California San Diego, San Diego, California
| | - Joseph Califano
- Moores Cancer Center, University of California San Diego, San Diego, California. .,Division of Otolaryngology - Head and Neck Surgery, University of California San Diego, San Diego, California
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27
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Li X, Jiang M, Chen D, Xu B, Wang R, Chu Y, Wang W, Zhou L, Lei Z, Nie Y, Fan D, Shang Y, Wu K, Liang J. miR-148b-3p inhibits gastric cancer metastasis by inhibiting the Dock6/Rac1/Cdc42 axis. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2018; 37:71. [PMID: 29587866 PMCID: PMC5872400 DOI: 10.1186/s13046-018-0729-z] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 03/08/2018] [Indexed: 12/19/2022]
Abstract
Background Our previous work showed that some Rho GTPases, including Rho, Rac1 and Cdc42, play critical roles in gastric cancer (GC); however, how they are regulated in GC remains largely unknown. In this study, we aimed to investigate the roles and molecular mechanisms of Dock6, an atypical Rho guanine nucleotide exchange factor (GEF), in GC metastasis. Methods The expression levels of Dock6 and miR-148b-3p in GC tissues and paired nontumor tissues were determined by immunohistochemistry (IHC) and in situ hybridization (ISH), respectively. The correlation between Dock6/miR-148b-3p expression and the overall survival of GC patients was calculated by the Kaplan-Meier method and log-rank test. The roles of Dock6 and miR-148b-3p in GC were investigated by in vitro and in vivo functional studies. Rac1 and Cdc42 activation was investigated by GST pull-down assays. The inhibition of Dock6 transcription by miR-148b-3p was determined by luciferase reporter assays. Results A significant increase in Dock6 expression was found in GC tissues compared with nontumor tissues, and its positive expression was associated with lymph node metastasis and a higher TNM stage. Patients with positive Dock6 expression exhibited shorter overall survival periods than patients with negative Dock6 expression. Dock6 promoted GC migration and invasion by increasing the activation of Rac1 and Cdc42. miR-148b-3p expression was negatively correlated with Dock6 expression in GC, and it decreased the motility of GC cells by inhibiting the Dock6/Rac1/Cdc42 axis. Conclusions Dock6 was over-expressed in GC tissues, and its positive expression was associated with GC metastasis and indicated poor prognosis of GC patients. Targeting of Dock6 by miR-148b-3p could activate Rac1 and Cdc42, directly affecting the motility of GC cells. Targeting the Dock6-Rac1/Cdc42 axis could serve as a new therapeutic strategy for GC treatment. Electronic supplementary material The online version of this article (10.1186/s13046-018-0729-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xiaowei Li
- State Key Laboratory of Cancer Biology & National Clinical Research Center for Digestive Diseases and Xijing Hospital of Digestive Diseases, Fourth Military Medical University, 127 West Changle Road, Xi'an, Shaanxi, 710032, China
| | - Mingzuo Jiang
- State Key Laboratory of Cancer Biology & National Clinical Research Center for Digestive Diseases and Xijing Hospital of Digestive Diseases, Fourth Military Medical University, 127 West Changle Road, Xi'an, Shaanxi, 710032, China
| | - Di Chen
- State Key Laboratory of Cancer Biology & National Clinical Research Center for Digestive Diseases and Xijing Hospital of Digestive Diseases, Fourth Military Medical University, 127 West Changle Road, Xi'an, Shaanxi, 710032, China
| | - Bing Xu
- State Key Laboratory of Cancer Biology & National Clinical Research Center for Digestive Diseases and Xijing Hospital of Digestive Diseases, Fourth Military Medical University, 127 West Changle Road, Xi'an, Shaanxi, 710032, China.,Department of Gastroenterology, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi Province, 710004, China
| | - Rui Wang
- National-Local Joint Engineering Research Center of Biodiagnostics & Biotheraphy, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, 710032, China
| | - Yi Chu
- State Key Laboratory of Cancer Biology & National Clinical Research Center for Digestive Diseases and Xijing Hospital of Digestive Diseases, Fourth Military Medical University, 127 West Changle Road, Xi'an, Shaanxi, 710032, China
| | - Weijie Wang
- State Key Laboratory of Cancer Biology & National Clinical Research Center for Digestive Diseases and Xijing Hospital of Digestive Diseases, Fourth Military Medical University, 127 West Changle Road, Xi'an, Shaanxi, 710032, China
| | - Lin Zhou
- Department of Gastroenterology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, 210008, China
| | - Zhijie Lei
- State Key Laboratory of Cancer Biology & National Clinical Research Center for Digestive Diseases and Xijing Hospital of Digestive Diseases, Fourth Military Medical University, 127 West Changle Road, Xi'an, Shaanxi, 710032, China
| | - Yongzhan Nie
- State Key Laboratory of Cancer Biology & National Clinical Research Center for Digestive Diseases and Xijing Hospital of Digestive Diseases, Fourth Military Medical University, 127 West Changle Road, Xi'an, Shaanxi, 710032, China
| | - Daiming Fan
- State Key Laboratory of Cancer Biology & National Clinical Research Center for Digestive Diseases and Xijing Hospital of Digestive Diseases, Fourth Military Medical University, 127 West Changle Road, Xi'an, Shaanxi, 710032, China
| | - Yulong Shang
- State Key Laboratory of Cancer Biology & National Clinical Research Center for Digestive Diseases and Xijing Hospital of Digestive Diseases, Fourth Military Medical University, 127 West Changle Road, Xi'an, Shaanxi, 710032, China.
| | - Kaichun Wu
- State Key Laboratory of Cancer Biology & National Clinical Research Center for Digestive Diseases and Xijing Hospital of Digestive Diseases, Fourth Military Medical University, 127 West Changle Road, Xi'an, Shaanxi, 710032, China.
| | - Jie Liang
- State Key Laboratory of Cancer Biology & National Clinical Research Center for Digestive Diseases and Xijing Hospital of Digestive Diseases, Fourth Military Medical University, 127 West Changle Road, Xi'an, Shaanxi, 710032, China.
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28
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Rastogi D, Nico J, Johnston AD, Tobias TAM, Jorge Y, Macian F, Greally JM. CDC42-related genes are upregulated in helper T cells from obese asthmatic children. J Allergy Clin Immunol 2018; 141:539-548.e7. [PMID: 28479334 PMCID: PMC5671374 DOI: 10.1016/j.jaci.2017.04.016] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 04/04/2017] [Accepted: 04/18/2017] [Indexed: 01/21/2023]
Abstract
BACKGROUND Pediatric obesity-related asthma is more severe and less responsive to medications than asthma in normal-weight children. Obese asthmatic children have nonatopic TH1-polarized systemic inflammation that correlates with pulmonary function deficits, but the pathways underlying TH1-polarized inflammation are not well understood. OBJECTIVE We compared the CD4+ T-cell transcriptome in obese children with asthma with that in normal-weight children with asthma to identify key differentially expressed genes associated with TH1-polarized inflammation. METHODS CD4+ T-cell transcriptome-wide differential gene expression was compared between 21 obese and 21 normal-weight children by using directional RNA sequencing. High-confidence differentially expressed genes were verified in the first cohort and validated in a second cohort of 20 children (10 obese and 10 normal-weight children) by using quantitative RT-PCR. RESULTS Transcriptome-wide differential gene expression among obese asthmatic children was enriched for genes, including VAV2, DOCK5, PAK3, PLD1, CDC42EP4, and CDC42PBB, which are associated with CDC42, a small guanosine triphosphate protein linked to T-cell activation. Upregulation of MLK3 and PLD1, genes downstream of CDC42 in the mitogen-activated protein kinase and mammalian target of rapamycin pathways and the inverse correlation of CDC42EP4 and DOCK5 transcript counts with FEV1/FVC ratio together support a role of CDC42 in the TH1 polarization and pulmonary function deficits found in patients with obesity-related asthma. CONCLUSIONS Our study identifies the CDC42 pathway as a novel target that is upregulated in TH cells of obese asthmatic children, suggesting its role in nonatopic TH1-polarized systemic inflammation and pulmonary function deficits found in patients with pediatric obesity-related asthma.
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Affiliation(s)
- Deepa Rastogi
- Department of Pediatrics, Albert Einstein College of Medicine, Bronx, NY.
| | - John Nico
- Department of Pediatrics, Albert Einstein College of Medicine, Bronx, NY
| | - Andrew D Johnston
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY
| | | | - Yurydia Jorge
- Department of Pediatrics, Albert Einstein College of Medicine, Bronx, NY
| | - Fernando Macian
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY
| | - John M Greally
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY
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29
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Akaiwa K, Namekata K, Azuchi Y, Guo X, Kimura A, Harada C, Mitamura Y, Harada T. Edaravone suppresses retinal ganglion cell death in a mouse model of normal tension glaucoma. Cell Death Dis 2017; 8:e2934. [PMID: 28703795 PMCID: PMC5550882 DOI: 10.1038/cddis.2017.341] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 06/06/2017] [Accepted: 06/19/2017] [Indexed: 01/16/2023]
Abstract
Glaucoma, one of the leading causes of irreversible blindness, is characterized by progressive degeneration of optic nerves and retinal ganglion cells (RGCs). In the mammalian retina, excitatory amino-acid carrier 1 (EAAC1) is expressed in neural cells, including RGCs. Loss of EAAC1 leads to RGC degeneration without elevated intraocular pressure (IOP) and exhibits glaucomatous pathology including glutamate neurotoxicity and oxidative stress. In the present study, we found that edaravone, a free radical scavenger that is used for treatment of acute brain infarction and amyotrophic lateral sclerosis (ALS), reduces oxidative stress and prevents RGC death and thinning of the inner retinal layer in EAAC1-deficient (KO) mice. In addition, in vivo electrophysiological analyses demonstrated that visual impairment in EAAC1 KO mice was ameliorated with edaravone treatment, clearly establishing that edaravone beneficially affects both histological and functional aspects of the glaucomatous retina. Our findings raise intriguing possibilities for the management of glaucoma by utilizing a widely prescribed drug for the treatment of acute brain infarction and ALS, edaravone, in combination with conventional treatments to lower IOP.
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Affiliation(s)
- Kei Akaiwa
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.,Department of Ophthalmology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan
| | - Kazuhiko Namekata
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Yuriko Azuchi
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Xiaoli Guo
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Atsuko Kimura
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Chikako Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Yoshinori Mitamura
- Department of Ophthalmology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan
| | - Takayuki Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.,Department of Ophthalmology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan
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30
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Targeting Oxidative Stress for Treatment of Glaucoma and Optic Neuritis. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:2817252. [PMID: 28270908 PMCID: PMC5320364 DOI: 10.1155/2017/2817252] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 01/09/2017] [Indexed: 12/31/2022]
Abstract
Glaucoma is a neurodegenerative disease of the eye and it is one of the leading causes of blindness. Glaucoma is characterized by progressive degeneration of retinal ganglion cells (RGCs) and their axons, namely, the optic nerve, usually associated with elevated intraocular pressure (IOP). Current glaucoma therapies target reduction of IOP, but since RGC death is the cause of irreversible vision loss, neuroprotection may be an effective strategy for glaucoma treatment. One of the risk factors for glaucoma is increased oxidative stress, and drugs with antioxidative properties including valproic acid and spermidine, as well as inhibition of apoptosis signal-regulating kinase 1, an enzyme that is involved in oxidative stress, have been reported to prevent glaucomatous retinal degeneration in mouse models of glaucoma. Optic neuritis is a demyelinating inflammation of the optic nerve that presents with visual impairment and it is commonly associated with multiple sclerosis, a chronic demyelinating disease of the central nervous system. Although steroids are commonly used for treatment of optic neuritis, reduction of oxidative stress by approaches such as gene therapy is effective in ameliorating optic nerve demyelination in preclinical studies. In this review, we discuss oxidative stress as a therapeutic target for glaucoma and optic neuritis.
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31
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Kimura A, Namekata K, Guo X, Harada C, Harada T. Neuroprotection, Growth Factors and BDNF-TrkB Signalling in Retinal Degeneration. Int J Mol Sci 2016; 17:ijms17091584. [PMID: 27657046 PMCID: PMC5037849 DOI: 10.3390/ijms17091584] [Citation(s) in RCA: 120] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 09/01/2016] [Accepted: 09/14/2016] [Indexed: 12/18/2022] Open
Abstract
Neurotrophic factors play key roles in the development and survival of neurons. The potent neuroprotective effects of neurotrophic factors, including brain-derived neurotrophic factor (BDNF), ciliary neurotrophic factor (CNTF), glial cell-line derived neurotrophic factor (GDNF) and nerve growth factor (NGF), suggest that they are good therapeutic candidates for neurodegenerative diseases. Glaucoma is a neurodegenerative disease of the eye that causes irreversible blindness. It is characterized by damage to the optic nerve, usually due to high intraocular pressure (IOP), and progressive degeneration of retinal neurons called retinal ganglion cells (RGCs). Current therapy for glaucoma focuses on reduction of IOP, but neuroprotection may also be beneficial. BDNF is a powerful neuroprotective agent especially for RGCs. Exogenous application of BDNF to the retina and increased BDNF expression in retinal neurons using viral vector systems are both effective in protecting RGCs from damage. Furthermore, induction of BDNF expression by agents such as valproic acid has also been beneficial in promoting RGC survival. In this review, we discuss the therapeutic potential of neurotrophic factors in retinal diseases and focus on the differential roles of glial and neuronal TrkB in neuroprotection. We also discuss the role of neurotrophic factors in neuroregeneration.
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Affiliation(s)
- Atsuko Kimura
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan.
| | - Kazuhiko Namekata
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan.
| | - Xiaoli Guo
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan.
| | - Chikako Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan.
| | - Takayuki Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan.
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Central visual pathways in glaucoma: evidence for distal mechanisms of neuronal self-repair. J Neuroophthalmol 2016; 35 Suppl 1:S29-37. [PMID: 26274834 DOI: 10.1097/wno.0000000000000291] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
As in other age-related neurodegenerative diseases, progression of neurodegeneration in glaucoma involves early axonopathy. In glaucoma, this is marked by degradation of active transport along retinal ganglion cell (RGC) axons projecting from the retina to the brain. In experimental systems, transport degradation occurs first in the most distal site in the RGC projection, the superior colliculus (SC) of the midbrain. Even as degradation progresses from one retinotopic sector to the next, important structures in the affected sectors persist, including synapses from RGC axon terminals onto SC neurons. This structural persistence is accompanied by focally increased brain-derived neurotrophic factor in hypertrophic SC astrocyte glia and defines a therapeutic window of opportunity. Thus, central brain structures in glaucoma may respond to disease-relevant stress by induction of mechanisms useful for maintaining retinal signals.
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Abstract
Rho GTPases are crucial signaling molecules that regulate a plethora of biological functions. Traditional biochemical, cell biological, and genetic approaches have founded the basis of Rho GTPase biology. The development of biosensors then allowed measuring Rho GTPase activity with unprecedented spatio-temporal resolution. This revealed that Rho GTPase activity fluctuates on time and length scales of tens of seconds and micrometers, respectively. In this review, we describe Rho GTPase activity patterns observed in different cell systems. We then discuss the growing body of evidence that upstream regulators such as guanine nucleotide exchange factors and GTPase-activating proteins shape these patterns by precisely controlling the spatio-temporal flux of Rho GTPase activity. Finally, we comment on additional mechanisms that might feed into the regulation of these signaling patterns and on novel technologies required to dissect this spatio-temporal complexity.
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Affiliation(s)
| | - Olivier Pertz
- Department of Biomedicine, University of Basel, Basel, Switzerland; Institute of Cell Biology, University of Bern, Bern, Switzerland
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Singman EL, Daphalapurkar N, White H, Nguyen TD, Panghat L, Chang J, McCulley T. Indirect traumatic optic neuropathy. Mil Med Res 2016; 3:2. [PMID: 26759722 PMCID: PMC4709956 DOI: 10.1186/s40779-016-0069-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 01/04/2016] [Indexed: 01/12/2023] Open
Abstract
Indirect traumatic optic neuropathy (ITON) refers to optic nerve injury resulting from impact remote to the optic nerve. The mechanism of injury is not understood, and there are no confirmed protocols for prevention, mitigation or treatment. Most data concerning this condition comes from case series of civilian patients suffering blunt injury, such as from sports- or motor vehicle-related concussion, rather than military-related ballistic or blast damage. Research in this field will likely require the development of robust databases to identify patients with ITON and follow related outcomes, in addition to both in-vivo animal and virtual human models to study the mechanisms of damage and potential therapies.
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Affiliation(s)
- Eric L Singman
- Wilmer Eye Institute at Johns Hopkins Hospital, Baltimore, Maryland USA
| | | | - Helen White
- Director of Informatics and Information Management, Vision Center of Excellence [VCE], Office of the Assistant Secretary of Defense for Health Affairs [ASD-HA], United States Department of Defense [DOD], Walter Reed National Military Medical Center, Bethesda, MD USA
| | - Thao D Nguyen
- Whiting School of Engineering, Johns Hopkins University, Baltimore, MD USA
| | - Lijo Panghat
- Whiting School of Engineering, Johns Hopkins University, Baltimore, MD USA
| | - Jessica Chang
- Wilmer Eye Institute at Johns Hopkins Hospital, Baltimore, Maryland USA
| | - Timothy McCulley
- Wilmer Eye Institute at Johns Hopkins Hospital, Baltimore, Maryland USA
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35
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Alvarez-Miranda EA, Sinnl M, Farhan H. Alteration of Golgi Structure by Stress: A Link to Neurodegeneration? Front Neurosci 2015; 9:435. [PMID: 26617486 PMCID: PMC4641911 DOI: 10.3389/fnins.2015.00435] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 10/29/2015] [Indexed: 12/14/2022] Open
Abstract
The Golgi apparatus is well-known for its role as a sorting station in the secretory pathway as well as for its role in regulating post-translational protein modification. Another role for the Golgi is the regulation of cellular signaling by spatially regulating kinases, phosphatases, and GTPases. All these roles make it clear that the Golgi is a central regulator of cellular homeostasis. The response to stress and the initiation of adaptive responses to cope with it are fundamental abilities of all living cells. It was shown previously that the Golgi undergoes structural rearrangements under various stress conditions such as oxidative or osmotic stress. Neurodegenerative diseases are also frequently associated with alterations of Golgi morphology and many stress factors have been described to play an etiopathological role in neurodegeneration. It is however unclear whether the stress-Golgi connection plays a role in neurodegenerative diseases. Using a combination of bioinformatics modeling and literature mining, we will investigate evidence for such a tripartite link and we ask whether stress-induced Golgi arrangements are cause or consequence in neurodegeneration.
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Affiliation(s)
| | - Markus Sinnl
- Department of Statistics and Operations Research, University of Vienna Vienna, Austria
| | - Hesso Farhan
- Biotechnology Institute Thurgau Kreuzlingen, Switzerland ; Department of Biology, University of Konstanz Konstanz, Germany
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36
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Harada C, Azuchi Y, Noro T, Guo X, Kimura A, Namekata K, Harada T. TrkB Signaling in Retinal Glia Stimulates Neuroprotection after Optic Nerve Injury. THE AMERICAN JOURNAL OF PATHOLOGY 2015; 185:3238-47. [PMID: 26476348 DOI: 10.1016/j.ajpath.2015.08.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 08/13/2015] [Accepted: 08/20/2015] [Indexed: 12/13/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) regulates neural cell survival mainly by activating TrkB receptors. Several lines of evidence support a key role for BDNF-TrkB signaling in survival of adult retinal ganglion cells in animal models of optic nerve injury (ONI), but the neuroprotective effect of exogenous BDNF is transient. Glial cells have recently attracted considerable attention as mediators of neural cell survival, and TrkB expression in retinal glia suggests its role in neuroprotection. To elucidate this point directly, we examined the effect of ONI on TrkB(flox/flox):glial fibrillary acidic protein (GFAP)-Cre+ (TrkB(GFAP)) knockout (KO) mice, in which TrkB is deleted in retinal glial cells. ONI markedly increased mRNA expression levels of basic fibroblast growth factor (bFGF) in wild-type (WT) mice but not in TrkB(GFAP) KO mice. Immunohistochemical analysis at 7 days after ONI (d7) revealed bFGF up-regulation mainly occurred in Müller glia. ONI-induced retinal ganglion cell loss in WT mice was consistently mild compared with TrkB(GFAP) KO mice at d7. On the other hand, ONI severely decreased TrkB expression in both WT and TrkB(GFAP) KO mice after d7, and the severity of retinal degeneration was comparable with TrkB(GFAP) KO mice at d14. Our data provide direct evidence that glial TrkB signaling plays an important role in the early stage of neural protection after traumatic injury.
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Affiliation(s)
- Chikako Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Yuriko Azuchi
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Takahiko Noro
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan; Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan
| | - Xiaoli Guo
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Atsuko Kimura
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Kazuhiko Namekata
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.
| | - Takayuki Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
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37
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Demonbreun AR, Biersmith BH, McNally EM. Membrane fusion in muscle development and repair. Semin Cell Dev Biol 2015; 45:48-56. [PMID: 26537430 PMCID: PMC4679555 DOI: 10.1016/j.semcdb.2015.10.026] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 10/15/2015] [Indexed: 12/16/2022]
Abstract
Mature skeletal muscle forms from the fusion of skeletal muscle precursor cells, myoblasts. Myoblasts fuse to other myoblasts to generate multinucleate myotubes during myogenesis, and myoblasts also fuse to other myotubes during muscle growth and repair. Proteins within myoblasts and myotubes regulate complex processes such as elongation, migration, cell adherence, cytoskeletal reorganization, membrane coalescence, and ultimately fusion. Recent studies have identified cell surface proteins, intracellular proteins, and extracellular signaling molecules required for the proper fusion of muscle. Many proteins that actively participate in myoblast fusion also coordinate membrane repair. Here we will review mammalian membrane fusion with specific attention to proteins that mediate myoblast fusion and muscle repair.
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Fine-Tuning of the Actin Cytoskeleton and Cell Adhesion During Drosophila Development by the Unconventional Guanine Nucleotide Exchange Factors Myoblast City and Sponge. Genetics 2015; 200:551-67. [PMID: 25908317 DOI: 10.1534/genetics.115.177063] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 04/18/2015] [Indexed: 01/03/2023] Open
Abstract
The evolutionarily conserved Dock proteins function as unconventional guanine nucleotide exchange factors (GEFs). Upon binding to engulfment and cell motility (ELMO) proteins, Dock-ELMO complexes activate the Rho family of small GTPases to mediate a diverse array of biological processes, including cell motility, apoptotic cell clearance, and axon guidance. Overlapping expression patterns and functional redundancy among the 11 vertebrate Dock family members, which are subdivided into four families (Dock A, B, C, and D), complicate genetic analysis. In both vertebrate and invertebrate systems, the actin dynamics regulator, Rac, is the target GTPase of the Dock-A subfamily. However, it remains unclear whether Rac or Rap1 are the in vivo downstream GTPases of the Dock-B subfamily. Drosophila melanogaster is an excellent genetic model organism for understanding Dock protein function as its genome encodes one ortholog per subfamily: Myoblast city (Mbc; Dock A) and Sponge (Spg; Dock B). Here we show that the roles of Spg and Mbc are not redundant in the Drosophila somatic muscle or the dorsal vessel. Moreover, we confirm the in vivo role of Mbc upstream of Rac and provide evidence that Spg functions in concert with Rap1, possibly to regulate aspects of cell adhesion. Together these data show that Mbc and Spg can have different downstream GTPase targets. Our findings predict that the ability to regulate downstream GTPases is dependent on cellular context and allows for the fine-tuning of actin cytoskeletal or cell adhesion events in biological processes that undergo cell morphogenesis.
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Noro T, Namekata K, Kimura A, Guo X, Azuchi Y, Harada C, Nakano T, Tsuneoka H, Harada T. Spermidine promotes retinal ganglion cell survival and optic nerve regeneration in adult mice following optic nerve injury. Cell Death Dis 2015; 6:e1720. [PMID: 25880087 PMCID: PMC4650557 DOI: 10.1038/cddis.2015.93] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 02/13/2015] [Accepted: 03/02/2015] [Indexed: 12/19/2022]
Abstract
Spermidine acts as an endogenous free radical scavenger and inhibits the action of reactive oxygen species. In this study, we examined the effects of spermidine on retinal ganglion cell (RGC) death in a mouse model of optic nerve injury (ONI). Daily ingestion of spermidine reduced RGC death following ONI and sequential in vivo retinal imaging revealed that spermidine effectively prevented retinal degeneration. Apoptosis signal-regulating kinase-1 (ASK1) is an evolutionarily conserved mitogen-activated protein kinase kinase kinase and has an important role in ONI-induced RGC apoptosis. We demonstrated that spermidine suppresses ONI-induced activation of the ASK1-p38 mitogen-activated protein kinase pathway. Moreover, production of chemokines important for microglia recruitment was decreased with spermidine treatment and, consequently, accumulation of retinal microglia is reduced. In addition, the ONI-induced expression of inducible nitric oxide synthase in the retina was inhibited with spermidine treatment, particularly in microglia. Furthermore, daily spermidine intake enhanced optic nerve regeneration in vivo. Our findings indicate that spermidine stimulates neuroprotection as well as neuroregeneration, and may be useful for treatment of various neurodegenerative diseases including glaucoma.
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Affiliation(s)
- T Noro
- 1] Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan [2] Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan
| | - K Namekata
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - A Kimura
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - X Guo
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Y Azuchi
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - C Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - T Nakano
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan
| | - H Tsuneoka
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan
| | - T Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
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40
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Regulating Rac in the nervous system: molecular function and disease implication of Rac GEFs and GAPs. BIOMED RESEARCH INTERNATIONAL 2015; 2015:632450. [PMID: 25879033 PMCID: PMC4388020 DOI: 10.1155/2015/632450] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 03/06/2015] [Indexed: 12/11/2022]
Abstract
Rho family GTPases, including RhoA, Rac1, and Cdc42 as the most studied members, are master regulators of actin cytoskeletal organization. Rho GTPases control various aspects of the nervous system and are associated with a number of neuropsychiatric and neurodegenerative diseases. The activity of Rho GTPases is controlled by two families of regulators, guanine nucleotide exchange factors (GEFs) as the activators and GTPase-activating proteins (GAPs) as the inhibitors. Through coordinated regulation by GEFs and GAPs, Rho GTPases act as converging signaling molecules that convey different upstream signals in the nervous system. So far, more than 70 members of either GEFs or GAPs of Rho GTPases have been identified in mammals, but only a small subset of them have well-known functions. Thus, characterization of important GEFs and GAPs in the nervous system is crucial for the understanding of spatiotemporal dynamics of Rho GTPase activity in different neuronal functions. In this review, we summarize the current understanding of GEFs and GAPs for Rac1, with emphasis on the molecular function and disease implication of these regulators in the nervous system.
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41
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Awad R, Sévajol M, Ayala I, Chouquet A, Frachet P, Gans P, Reiser JB, Kleman JP. The SH3 regulatory domain of the hematopoietic cell kinase Hck binds ELMO via its polyproline motif. FEBS Open Bio 2015; 5:99-106. [PMID: 25737835 PMCID: PMC4338372 DOI: 10.1016/j.fob.2015.01.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 01/23/2015] [Accepted: 01/30/2015] [Indexed: 12/27/2022] Open
Abstract
Eukaryotic EnguLfment and cell MOtility (ELMO) proteins form an evolutionary conserved family of regulators involved in small GTPase dependent actin remodeling processes that regulates the guanine exchange factor activity of some of the Downstream Of CrK (DOCK) family members. Gathered data strongly suggest that DOCK activation by ELMO and the subsequent signaling result from a subtle balance in the binding of partners to ELMO. Among its putative upward modulators, the Hematopoietic cell kinase (Hck), a member of the Src kinase superfamily, has been identified as a binding partner and a specific tyrosine kinase for ELMO1. Indeed, Hck is implicated in distinct molecular signaling pathways governing phagocytosis, cell adhesion, and migration of hematopoietic cells. Although ELMO1 has been shown to interact with the regulatory Src Homology 3 (SH3) domain of Hck, no direct evidence indicating the mode of interaction between Hck and ELMO1 have been provided in the literature. In the present study, we report convergent pieces of evidence that demonstrate the specific interaction between the SH3 domain of Hck and the polyproline motif of ELMO1. Our results also suggest that the tyrosine-phosphorylation state of ELMO1 tail might act as a putative modulator of Hck kinase activity towards ELMO1 that in turn participates in DOCK180 activation and further triggers subsequent signaling towards actin remodeling.
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Key Words
- DOCK, Downstream Of CrK protein family
- EAD, ELMO Autoregulatory Domain
- EID, ELMO Inhibitory Domain
- ELMO
- ELMO, EnguLfment and cell MOtility protein family
- ERM, Ezrin–Radixin–Moesin protein family
- FRET, Förster (Fluorescence) resonance energy transfer
- GEF, Guanine nucleotide Exchange Factor
- GSH, Glutathione (reduced)
- GST, Glutathione S-Transferase
- Hck
- Hck, Hematopoietic cell kinase
- PH, Pleckstrin Homology domain
- Phagocytosis
- Phosphorylation
- Polyproline
- PxP, Polyproline motif
- RBD, Rho-Binding Domain
- SH3
- SH3, Src Homology 3 domain
- TAMs, Tyro3, Axl and Mer receptor tyrosine kinase family
- TEV, Tobacco Etch Virus
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Affiliation(s)
- Rida Awad
- Univ. Grenoble Alpes, IBS, F-38044 Grenoble, France
| | | | - Isabel Ayala
- Univ. Grenoble Alpes, IBS, F-38044 Grenoble, France
| | | | | | - Pierre Gans
- Univ. Grenoble Alpes, IBS, F-38044 Grenoble, France
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42
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Kimura A, Guo X, Noro T, Harada C, Tanaka K, Namekata K, Harada T. Valproic acid prevents retinal degeneration in a murine model of normal tension glaucoma. Neurosci Lett 2015; 588:108-13. [DOI: 10.1016/j.neulet.2014.12.054] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Revised: 12/22/2014] [Accepted: 12/25/2014] [Indexed: 12/28/2022]
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43
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Lefort R. Reversing synapse loss in Alzheimer's disease: Rho-guanosine triphosphatases and insights from other brain disorders. Neurotherapeutics 2015; 12:19-28. [PMID: 25588580 PMCID: PMC4322073 DOI: 10.1007/s13311-014-0328-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
Alzheimer's disease (AD) is a monumental public health crisis with no effective cure or treatment. To date, therapeutic strategies have focused almost exclusively on upstream signaling events in the disease, namely on β-amyloid and amyloid precursor protein processing, and have, unfortunately, yielded few, if any, promising results. An alternative approach may be to target signaling events downstream of β-amyloid and even tau. However, with so many pathways already linked to the disease, understanding which ones are "drivers" versus "passengers" in the pathogenesis of the disease remains a tremendous challenge. Given the critical roles of Rho-guanosine triphosphatases (GTPases) in regulating the actin cytoskeleton and spine dynamics, and the strong association between spine abnormalities and cognition, it is not surprising that mutations in a number of genes involved in Rho-GTPase signaling have been implicated in several brain disorders, including schizophrenia and autism. And now, there is mounting literature implicating Rho-GTPase signaling in AD pathogenesis as well. Here, I review this evidence, with a particular emphasis on the regulators of Rho-GTPase signaling, namely guanine nucleotide exchange factors and GTPase-activating proteins. Several of these have been linked to various aspects of AD, and each offers a novel potential therapeutic target for AD.
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Affiliation(s)
- Roger Lefort
- The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, and Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY, 10032, USA,
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44
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Droppelmann CA, Campos-Melo D, Volkening K, Strong MJ. The emerging role of guanine nucleotide exchange factors in ALS and other neurodegenerative diseases. Front Cell Neurosci 2014; 8:282. [PMID: 25309324 PMCID: PMC4159981 DOI: 10.3389/fncel.2014.00282] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 08/25/2014] [Indexed: 12/11/2022] Open
Abstract
Small GTPases participate in a broad range of cellular processes such as proliferation, differentiation, and migration. The exchange of GDP for GTP resulting in the activation of these GTPases is catalyzed by a group of enzymes called guanine nucleotide exchange factors (GEFs), of which two classes: Dbl-related exchange factors and the more recently described dedicator of cytokinesis proteins family exchange factors. Increasingly, deregulation of normal GEF activity or function has been associated with a broad range of disease states, including neurodegeneration and neurodevelopmental disorders. In this review, we examine this evidence with special emphasis on the novel role of Rho guanine nucleotide exchange factor (RGNEF/p190RhoGEF) in the pathogenesis of amyotrophic lateral sclerosis. RGNEF is the first neurodegeneration-linked GEF that regulates not only RhoA GTPase activation but also functions as an RNA binding protein that directly acts with low molecular weight neurofilament mRNA 3' untranslated region to regulate its stability. This dual role for RGNEF, coupled with the increasing understanding of the key role for GEFs in modulating the GTPase function in cell survival suggests a prominent role for GEFs in mediating a critical balance between cytotoxicity and neuroprotection which, when disturbed, contributes to neuronal loss.
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Affiliation(s)
- Cristian A Droppelmann
- Molecular Medicine Group, Robarts Research Institute, Western University London, ON, Canada
| | - Danae Campos-Melo
- Molecular Medicine Group, Robarts Research Institute, Western University London, ON, Canada
| | - Kathryn Volkening
- Molecular Medicine Group, Robarts Research Institute, Western University London, ON, Canada ; Department of Clinical Neurological Sciences, Schulich School of Medicine & Dentistry, Western University London, ON, Canada
| | - Michael J Strong
- Molecular Medicine Group, Robarts Research Institute, Western University London, ON, Canada ; Department of Clinical Neurological Sciences, Schulich School of Medicine & Dentistry, Western University London, ON, Canada
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45
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Namekata K, Kimura A, Harada C, Yoshida H, Matsumoto Y, Harada T. Dock3 protects myelin in the cuprizone model for demyelination. Cell Death Dis 2014; 5:e1395. [PMID: 25165881 PMCID: PMC4454328 DOI: 10.1038/cddis.2014.357] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 07/11/2014] [Accepted: 07/21/2014] [Indexed: 12/18/2022]
Abstract
Dedicator of cytokinesis 3 (Dock3) belongs to an atypical family of the guanine nucleotide exchange factors. It is predominantly expressed in the neural tissues and causes cellular morphological changes by activating the small GTPase Rac1. We previously reported that Dock3 overexpression protects retinal ganglion cells from excitotoxic cell death. Oligodendrocytes are the myelinating cells of axons in the central nervous system and these cells are damaged in demyelinating disorders including multiple sclerosis (MS) and optic neuritis. In this study, we examined if Dock3 is expressed in oligodendrocytes and if increasing Dock3 signals can suppress demyelination in a cuprizone-induced demyelination model, an animal model of MS. We demonstrate that Dock3 is expressed in oligodendrocytes and Dock3 overexpression protects myelin in the corpus callosum following cuprizone treatment. Furthermore, we show that cuprizone demyelinates optic nerves and the extent of demyelination is ameliorated in mice overexpressing Dock3. Cuprizone treatment impairs visual function, which was demonstrated by multifocal electroretinograms, an established non-invasive method, and Dock3 overexpression prevented this effect. In mice overexpressing Dock3, Erk activation is increased, suggesting this may at least partly explain the observed protective effects. Our findings suggest that Dock3 may be a therapeutic target for demyelinating disorders including optic neuritis.
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Affiliation(s)
- K Namekata
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - A Kimura
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - C Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - H Yoshida
- Department of Neuro-ophthalmology, Tokyo Metropolitan Neurological Hospital, Tokyo, Japan
| | - Y Matsumoto
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - T Harada
- 1] Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan [2] Department of Neuro-ophthalmology, Tokyo Metropolitan Neurological Hospital, Tokyo, Japan
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46
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Semba K, Namekata K, Kimura A, Harada C, Katome T, Yoshida H, Mitamura Y, Harada T. Dock3 overexpression and p38 MAPK inhibition synergistically stimulate neuroprotection and axon regeneration after optic nerve injury. Neurosci Lett 2014; 581:89-93. [PMID: 25172145 DOI: 10.1016/j.neulet.2014.08.034] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 08/19/2014] [Accepted: 08/19/2014] [Indexed: 10/24/2022]
Abstract
The dedicator of cytokinesis 3 (Dock3) is an atypical guanine nucleotide exchange factor that is predominantly expressed in the CNS. Dock3 exerts neuroprotective effects and stimulates optic nerve regeneration. The p38 mitogen-activated protein kinase acts downstream of apoptosis signal-regulating kinase 1 (ASK1) signaling and plays an important role in neural cell death. We assessed a therapeutic efficacy of Dock3 stimulation and p38 inhibition in retinal degeneration induced by optic nerve injury (ONI). In vivo retinal imaging using optical coherence tomography revealed that ONI-induced retinal degeneration was ameliorated in SB203580 (a p38 inhibitor)-treated WT mice and PBS-treated Dock3 overexpressing (Dock3 Tg) mice, and SB203580 further stimulated retinal protection in Dock3 Tg mice. In addition, SB203580 increased the number of regenerating axons after ONI in both WT and Dock3 Tg mice. ONI-induced phosphorylation of ASK1, p38 and the N-methyl-d-aspartate receptor 2B subunit were suppressed in the retina of Dock3 Tg mice. Inhibition of the ASK1 pathway in Dock3 Tg mice suggests that Dock3 may have an antioxidant-like property. These results indicate that overexpression of Dock3 and pharmacological interruption of p38 have synergistic effects for both neuroprotection and axon regeneration, thus combined application may be beneficial for the treatment of ONI.
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Affiliation(s)
- Kentaro Semba
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan; Department of Ophthalmology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan
| | - Kazuhiko Namekata
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Atsuko Kimura
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Chikako Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Takashi Katome
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan; Department of Ophthalmology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan
| | - Hiroshi Yoshida
- Department of Neuro-ophthalmology, Tokyo Metropolitan Neurological Hospital, Fuchu, Tokyo, Japan
| | - Yoshinori Mitamura
- Department of Ophthalmology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan
| | - Takayuki Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan; Department of Ophthalmology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan; Department of Neuro-ophthalmology, Tokyo Metropolitan Neurological Hospital, Fuchu, Tokyo, Japan.
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