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Burnett SB, Culver AM, Simon TA, Rowson T, Frederick K, Palmer K, Murray SA, Davis SW, Patel RC. A frameshift mutation in the murine Prkra gene causes dystonia and exhibits abnormal cerebellar development and reduced eIF2α phosphorylation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.04.597421. [PMID: 38895245 PMCID: PMC11185611 DOI: 10.1101/2024.06.04.597421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Mutations in Prkra gene, which encodes PACT/RAX cause early onset primary dystonia DYT-PRKRA, a movement disorder that disrupts coordinated muscle movements. PACT/RAX activates protein kinase R (PKR, aka EIF2AK2) by a direct interaction in response to cellular stressors to mediate phosphorylation of the α subunit of the eukaryotic translation initiation factor 2 (eIF2α). Mice homozygous for a naturally arisen, recessively inherited frameshift mutation, Prkra lear-5J exhibit progressive dystonia. In the present study, we investigate the biochemical and developmental consequences of the Prkra lear-5J mutation. Our results indicate that the truncated PACT/RAX protein retains its ability to interact with PKR, however, it inhibits PKR activation. Furthermore, mice homozygous for the mutation have abnormalities in the cerebellar development as well as a severe lack of dendritic arborization of Purkinje neurons. Additionally, reduced eIF2α phosphorylation is noted in the cerebellums and Purkinje neurons of the homozygous Prkra lear-5J mice. These results indicate that PACT/RAX mediated regulation of PKR activity and eIF2α phosphorylation plays a role in cerebellar development and contributes to the dystonia phenotype resulting from this mutation.
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Affiliation(s)
| | | | | | | | | | - Kristina Palmer
- The Jackson Laboratory, 600 Main St., Bar Harbor, ME 04609, USA
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Wei L, Wang W, Yao J, Cui Z, Xu Z, Ding H, Wu X, Wang D, Luo J, Ke ZJ. PACT promotes the metastasis of basal-like breast cancer through Rac1 SUMOylation and activation. Oncogene 2022; 41:4282-4294. [PMID: 35974143 DOI: 10.1038/s41388-022-02431-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 07/27/2022] [Accepted: 07/29/2022] [Indexed: 12/13/2022]
Abstract
Most basal-like breast cancers (BLBCs) are triple-negative breast cancers (TNBCs), which is associated with high malignancy, high rate of recurrence and distant metastasis, and poor prognosis among all types of breast cancer. However, there are currently no effective therapies for BLBC. Furthermore, chemoresistance limits the therapeutic options for BLBC treatment. In this study, we screen out protein activator of the interferon-induced protein kinase (PACT) as an essential gene in BLBC metastasis. We find that high PACT expression level was associated with poor prognosis among BLBC patients. In vivo and in vitro investigations indicated that PACT could regulate BLBC metastasis by interacting with SUMO-conjugating enzyme Ubc9 to stimulate the SUMOylation and thus consequently the activation of Rac1. BLBC patients receiving chemotherapy presents poorer prognosis with PACT high expression, and PACT disruption sensitizes experimental mammary tumor metastases to chemotherapy, thus providing insights to consider PACT as a potential therapeutic target to overcome acquired chemoresistance in BLBC.
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Affiliation(s)
- Luyao Wei
- The Academy of Integrative Medicine, Shanghai Key Laboratory of Health Identification and Assessment, Department of Biochemistry, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, 201203, PR China
| | - Wantao Wang
- The Academy of Integrative Medicine, Shanghai Key Laboratory of Health Identification and Assessment, Department of Biochemistry, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, 201203, PR China
| | - Junxia Yao
- Department of Pathology, Qingpu Branch of Zhongshan Hospital Affiliated to Fudan University, 1158 Gongyuan Road, Shanghai, 201700, PR China
| | - Zhengyu Cui
- Department of Internal Medicine of Traditional Chinese Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, 200120, PR China
| | - Zihang Xu
- Department of Internal Classic of Medicine, School of Basic Medicine Sciences, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, 201203, PR China
| | - Hanqing Ding
- The Academy of Integrative Medicine, Shanghai Key Laboratory of Health Identification and Assessment, Department of Biochemistry, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, 201203, PR China
| | - Xiaojun Wu
- Shanghai Key Laboratory of Compound Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, 201203, PR China
| | - Deheng Wang
- The Academy of Integrative Medicine, Shanghai Key Laboratory of Health Identification and Assessment, Department of Biochemistry, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, 201203, PR China
| | - Jia Luo
- Department of Pathology, University of Iowa Carver College of Medicine, 51 Newton Road, Iowa City, IA, 52242, USA
| | - Zun-Ji Ke
- The Academy of Integrative Medicine, Shanghai Key Laboratory of Health Identification and Assessment, Department of Biochemistry, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai, 201203, PR China.
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Iskusnykh IY, Buddington RK, Chizhikov VV. Preterm birth disrupts cerebellar development by affecting granule cell proliferation program and Bergmann glia. Exp Neurol 2018; 306:209-221. [PMID: 29772246 PMCID: PMC6291230 DOI: 10.1016/j.expneurol.2018.05.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 05/09/2018] [Accepted: 05/12/2018] [Indexed: 01/17/2023]
Abstract
Preterm birth is a leading cause of long-term motor and cognitive deficits. Clinical studies suggest that some of these deficits result from disruption of cerebellar development, but the mechanisms that mediate cerebellar abnormalities in preterm infants are largely unknown. Furthermore, it remains unclear whether preterm birth and precocious exposure to the ex-utero environment directly disrupt cerebellar development or indirectly by increasing the probability of cerebellar injury, including that resulting from clinical interventions and protocols associated with the care of preterm infants. In this study, we analyzed the cerebellum of preterm pigs delivered via c-section at 91% term and raised for 10 days, until term-equivalent age. The pigs did not receive any treatments known or suspected to affect cerebellar development and had no evidence of brain damage. Term pigs sacrificed at birth were used as controls. Immunohistochemical analysis revealed that preterm birth did not affect either size or numbers of Purkinje cells or molecular layer interneurons at term-equivalent age. The number of granule cell precursors and Bergmann glial fibers, however, were reduced in preterm pigs. Preterm pigs had reduced proliferation but not differentiation of granule cells. qRT-PCR analysis of laser capture microdissected external granule cell layer showed that preterm pigs had a reduced expression of Ccnd1 (Cyclin D1), Ccnb1 (Cyclin B1), granule cell master regulatory transcription factor Atoh1, and signaling molecule Jag1. In vitro rescue experiments identified Jag1 as a central granule cell gene affected by preterm birth. Thus, preterm birth and precocious exposure to the ex-utero environment disrupt cerebellum by modulating expression of key cerebellar developmental genes, predominantly affecting development of granule precursors and Bergmann glia.
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Affiliation(s)
- Igor Y Iskusnykh
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | | | - Victor V Chizhikov
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA.
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4
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Abundant Focal Adhesion Kinase Causes Aberrant Neuronal Migration Via Its Phosphorylation at Tyr925. J Mol Neurosci 2017; 64:102-110. [DOI: 10.1007/s12031-017-1010-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 11/28/2017] [Indexed: 01/10/2023]
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Rittiner JE, Caffall ZF, Hernández-Martinez R, Sanderson SM, Pearson JL, Tsukayama KK, Liu AY, Xiao C, Tracy S, Shipman MK, Hickey P, Johnson J, Scott B, Stacy M, Saunders-Pullman R, Bressman S, Simonyan K, Sharma N, Ozelius LJ, Cirulli ET, Calakos N. Functional Genomic Analyses of Mendelian and Sporadic Disease Identify Impaired eIF2α Signaling as a Generalizable Mechanism for Dystonia. Neuron 2016; 92:1238-1251. [PMID: 27939583 DOI: 10.1016/j.neuron.2016.11.012] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 09/27/2016] [Accepted: 11/04/2016] [Indexed: 01/09/2023]
Abstract
Dystonia is a brain disorder causing involuntary, often painful movements. Apart from a role for dopamine deficiency in some forms, the cellular mechanisms underlying most dystonias are currently unknown. Here, we discover a role for deficient eIF2α signaling in DYT1 dystonia, a rare inherited generalized form, through a genome-wide RNAi screen. Subsequent experiments including patient-derived cells and a mouse model support both a pathogenic role and therapeutic potential for eIF2α pathway perturbations. We further find genetic and functional evidence supporting similar pathway impairment in patients with sporadic cervical dystonia, due to rare coding variation in the eIF2α effector ATF4. Considering also that another dystonia, DYT16, involves a gene upstream of the eIF2α pathway, these results mechanistically link multiple forms of dystonia and put forth a new overall cellular mechanism for dystonia pathogenesis, impairment of eIF2α signaling, a pathway known for its roles in cellular stress responses and synaptic plasticity.
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Affiliation(s)
| | | | | | | | - James L Pearson
- Department of Molecular Genetics and Microbiology, Duke University, Durham, NC 27708, USA; Department of RNAi Screening Facility, Duke University, Durham, NC 27708, USA
| | | | - Anna Y Liu
- Department of Neurology, Duke University, Durham, NC 27708, USA
| | - Changrui Xiao
- Department of Neurology, Duke University, Durham, NC 27708, USA
| | - Samantha Tracy
- Department of Neurology, Duke University, Durham, NC 27708, USA
| | | | - Patrick Hickey
- Department of Neurology, Duke University, Durham, NC 27708, USA
| | - Julia Johnson
- Department of Neurology, Duke University, Durham, NC 27708, USA
| | - Burton Scott
- Department of Neurology, Duke University, Durham, NC 27708, USA
| | - Mark Stacy
- Department of Neurology, Duke University, Durham, NC 27708, USA
| | - Rachel Saunders-Pullman
- Department of Neurology, Mount Sinai Beth Israel Medical Center, New York, NY 10003, USA; Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Susan Bressman
- Department of Neurology, Mount Sinai Beth Israel Medical Center, New York, NY 10003, USA; Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Kristina Simonyan
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Otolaryngology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Nutan Sharma
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Laurie J Ozelius
- Department of Neurology, Massachusetts General Hospital, Charlestown, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Elizabeth T Cirulli
- Department of Molecular Genetics and Microbiology, Duke University, Durham, NC 27708, USA; Center for Applied Genomics and Precision Medicine, Duke University, Durham, NC 27708, USA
| | - Nicole Calakos
- Department of Neurology, Duke University, Durham, NC 27708, USA; Department of Neurobiology, Duke University, Durham, NC 27708, USA.
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Hami J, Vafaei-Nezhad S, Ghaemi K, Sadeghi A, Ivar G, Shojae F, Hosseini M. Stereological study of the effects of maternal diabetes on cerebellar cortex development in rat. Metab Brain Dis 2016; 31:643-52. [PMID: 26842601 DOI: 10.1007/s11011-016-9802-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 01/27/2016] [Indexed: 10/22/2022]
Abstract
Diabetes during pregnancy is associated with the deficits in balance and motor coordination and altered social behaviors in offspring. In the present study, we have investigated the effect of maternal diabetes and insulin treatment on the cerebellar volume and morphogenesis of the cerebellar cortex of rat neonates during the first two postnatal weeks. Sprague Dawley female rats were maintained diabetic from a week before pregnancy through parturition. At the end of pregnancy, the male offspring euthanized on postnatal days (P) 0, 7, and 14. Cavalieri's principle and fractionator methods were used to estimate the cerebellar volume, the thickness and the number of cells in the different layers of the cerebellar cortex. In spite of P0, there was a significant reduction in the cerebellar volume and the thickness of the external granule, molecular, and internal granule layers between the diabetic and the control animals. In diabetic group, the granular and purkinje cell densities were increased at P0. Moreover, the number of granular and purkinje cells in the cerebellum of diabetic neonates was reduced in comparison with the control group at P7 and P14. There were no significant differences in either the volume and thickness or the number of cells in the different layers of the cerebellar cortex between the insulin-treated diabetic group and controls. Our data indicate that diabetes in pregnancy disrupts the morphogenesis of cerebellar cortex. This dysmorphogenesis may be part of the cascade of events through which diabetes during pregnancy affects motor coordination and social behaviors in offspring.
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Affiliation(s)
- Javad Hami
- Department of Anatomy, School of Medicine, Birjand University of Medical Sciences, Birjand, Iran
- Cellular & Molecular Research Center, Birjand University of Medical Sciences, Birjand, Iran
| | - Saeed Vafaei-Nezhad
- Department of Anatomy, School of Medicine, Birjand University of Medical Sciences, Birjand, Iran
| | - Kazem Ghaemi
- Department of Neurosurgery, School of Medicine, Birjand University of Medical Sciences, Birjand, Iran
| | - Akram Sadeghi
- Department of Anatomy and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Ghasem Ivar
- Department of Anatomy, School of Medicine, Birjand University of Medical Sciences, Birjand, Iran
| | - Fatemeh Shojae
- Department of Anatomy, School of Medicine, Birjand University of Medical Sciences, Birjand, Iran
| | - Mehran Hosseini
- Department of Public Health, Research Centre of Experimental Medicine, Deputy of Research and Technology, Birjand University of Medical Sciences, Birjand, Iran.
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Loss of the neuron-specific F-box protein FBXO41 models an ataxia-like phenotype in mice with neuronal migration defects and degeneration in the cerebellum. J Neurosci 2015; 35:8701-17. [PMID: 26063905 DOI: 10.1523/jneurosci.2133-14.2015] [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] [Indexed: 11/21/2022] Open
Abstract
The cerebellum is crucial for sensorimotor coordination. The cerebellar architecture not only requires proper development but also long-term integrity to ensure accurate functioning. Developmental defects such as impaired neuronal migration or neurodegeneration are thus detrimental to the cerebellum and can result in movement disorders including ataxias. In this study, we identify FBXO41 as a novel CNS-specific F-box protein that localizes to the centrosome and the cytoplasm of neurons and demonstrate that cytoplasmic FBXO41 promotes neuronal migration. Interestingly, deletion of the FBXO41 gene results in a severely ataxic gait in mice, which show delayed neuronal migration of granule neurons in the developing cerebellum in addition to deformities and degeneration of the mature cerebellum. We show that FBXO41 is a critical factor, not only for neuronal migration in the cerebellum, but also for its long-term integrity.
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