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Yang J, Feng J, Lv J, Chu X, Wei Y, Zhang Y, Li J, Sun Y, Li G, Jiang T, Huang J, Fan X. PTBP1-mediated repression of neuron-specific CDC42 splicing constitutes a genomic alteration-independent, developmentally conserved vulnerability in IDH-wildtype glioblastoma. Funct Integr Genomics 2024; 24:135. [PMID: 39117866 DOI: 10.1007/s10142-024-01412-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2024] [Revised: 07/22/2024] [Accepted: 07/25/2024] [Indexed: 08/10/2024]
Abstract
Gene co-expression networks may encode hitherto inadequately recognized vulnerabilities for adult gliomas. By identifying evolutionally conserved gene co-expression modules around EGFR (EM) or PDGFRA (PM), we recently proposed an EM/PM classification scheme, which assigns IDH-wildtype glioblastomas (GBM) into the EM subtype committed in neural stem cell compartment, IDH-mutant astrocytomas and oligodendrogliomas into the PM subtype committed in early oligodendrocyte lineage. Here, we report the identification of EM/PM subtype-specific gene co-expression networks and the characterization of hub gene polypyrimidine tract-binding protein 1 (PTBP1) as a genomic alteration-independent vulnerability in IDH-wildtype GBM. Supervised by the EM/PM classification scheme, we applied weighted gene co-expression network analysis to identify subtype-specific global gene co-expression modules. These gene co-expression modules were characterized for their clinical relevance, cellular origin and conserved expression pattern during brain development. Using lentiviral vector-mediated constitutive or inducible knockdown, we characterized the effects of PTBP1 on the survival of IDH-wildtype GBM cells, which was complemented with the analysis of PTBP1-depedent splicing pattern and overexpression of splicing target neuron-specific CDC42 (CDC42-N) isoform. Transcriptomes of adult gliomas can be robustly assigned into 4 large gene co-expression modules that are prognostically relevant and are derived from either malignant cells of the EM/PM subtypes or tumor microenvironment. The EM subtype is associated with a malignant cell-intrinsic gene module involved in pre-mRNA splicing, DNA replication and damage response, and chromosome segregation, and a microenvironment-derived gene module predominantly involved in extracellular matrix organization and infiltrating immune cells. The PM subtype is associated with two malignant cell-intrinsic gene modules predominantly involved in transcriptional regulation and mRNA translation, respectively. Expression levels of these gene modules are independent prognostic factors and malignant cell-intrinsic gene modules are conserved during brain development. Focusing on the EM subtype, we identified PTBP1 as the most significant hub for the malignant cell-intrinsic gene module. PTBP1 is not altered in most glioma genomes. PTBP1 represses the conserved splicing of CDC42-N. PTBP1 knockdown or CDC42-N overexpression disrupts actin cytoskeleton dynamics, causing accumulation of reactive oxygen species and cell apoptosis. PTBP1-mediated repression of CDC42-N splicing represents a potential genomic alteration-independent, developmentally conserved vulnerability in IDH-wildtype GBM.
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Affiliation(s)
- Junjie Yang
- Department of Biology, Beijing Key Laboratory of Gene Resource and Molecular Development, and Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, School of Life Sciences , Beijing Normal University, Beijing, China
| | - Jing Feng
- Department of Pathology, Sanbo Brain Hospital, Capital Medical University, Beijing, 100093, China
| | - Jing Lv
- Department of Biology, Beijing Key Laboratory of Gene Resource and Molecular Development, and Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, School of Life Sciences , Beijing Normal University, Beijing, China
| | - Xiaojing Chu
- Department of Biology, Beijing Key Laboratory of Gene Resource and Molecular Development, and Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, School of Life Sciences , Beijing Normal University, Beijing, China
| | - Yanfei Wei
- Department of Biology, Beijing Key Laboratory of Gene Resource and Molecular Development, and Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, School of Life Sciences , Beijing Normal University, Beijing, China
| | - Yunqiu Zhang
- Center of Growth Metabolism & Aging, Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Jiuyi Li
- College of Life Sciences, Sichuan Normal University, Chengdu, 610101, China
| | - Yingyu Sun
- Department of Biology, Beijing Key Laboratory of Gene Resource and Molecular Development, and Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, School of Life Sciences , Beijing Normal University, Beijing, China
| | - Guanzhang Li
- Beijing Neurosurgical Institute, Beijing, 100070, China
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, 100070, China
| | - Tao Jiang
- Beijing Neurosurgical Institute, Beijing, 100070, China
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, 100070, China
| | - Jinyan Huang
- Biomedical Big Data Center, the First Affiliated Hospital, Zhejiang University School of Medicine, 79 Qingchun Road, Hangzhou, 310003, Zhejiang, China
| | - Xiaolong Fan
- Department of Biology, Beijing Key Laboratory of Gene Resource and Molecular Development, and Key Laboratory of Cell Proliferation and Regulation Biology, Ministry of Education, School of Life Sciences , Beijing Normal University, Beijing, China.
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Coliță CI, Olaru DG, Coliță D, Hermann DM, Coliță E, Glavan D, Popa-Wagner A. Induced Coma, Death, and Organ Transplantation: A Physiologic, Genetic, and Theological Perspective. Int J Mol Sci 2023; 24:ijms24065744. [PMID: 36982814 PMCID: PMC10059721 DOI: 10.3390/ijms24065744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 03/13/2023] [Accepted: 03/15/2023] [Indexed: 03/19/2023] Open
Abstract
In the clinic, the death certificate is issued if brain electrical activity is no longer detectable. However, recent research has shown that in model organisms and humans, gene activity continues for at least 96 h postmortem. The discovery that many genes are still working up to 48 h after death questions our definition of death and has implications for organ transplants and forensics. If genes can be active up to 48 h after death, is the person technically still alive at that point? We discovered a very interesting parallel between genes that were upregulated in the brain after death and genes upregulated in the brains that were subjected to medically-induced coma, including transcripts involved in neurotransmission, proteasomal degradation, apoptosis, inflammation, and most interestingly, cancer. Since these genes are involved in cellular proliferation, their activation after death could represent the cellular reaction to escape mortality and raises the question of organ viability and genetics used for transplantation after death. One factor limiting the organ availability for transplantation is religious belief. However, more recently, organ donation for the benefit of humans in need has been seen as “posthumous giving of organs and tissues can be a manifestation of love spreading also to the other side of death”.
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Affiliation(s)
- Cezar-Ivan Coliță
- Doctoral School, University of Medicine and Pharmacy Carol Davila, 020276 Bucharest, Romania; (C.-I.C.)
| | - Denissa-Greta Olaru
- Department of Psychiatry, University for Medicine and Pharmacy Craiova, 200349 Craiova, Romania;
| | - Daniela Coliță
- Doctoral School, University of Medicine and Pharmacy Carol Davila, 020276 Bucharest, Romania; (C.-I.C.)
| | - Dirk M. Hermann
- Chair of Vascular Neurology, Dementia and Ageing, Department of Neurology, University Hospital Essen, 45147 Essen, Germany
| | - Eugen Coliță
- Doctoral School, University of Medicine and Pharmacy Carol Davila, 020276 Bucharest, Romania; (C.-I.C.)
| | - Daniela Glavan
- Department of Psychiatry, University for Medicine and Pharmacy Craiova, 200349 Craiova, Romania;
- Correspondence: (D.G.); (A.P.-W.)
| | - Aurel Popa-Wagner
- Department of Psychiatry, University for Medicine and Pharmacy Craiova, 200349 Craiova, Romania;
- Chair of Vascular Neurology, Dementia and Ageing, Department of Neurology, University Hospital Essen, 45147 Essen, Germany
- Correspondence: (D.G.); (A.P.-W.)
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Gharbi T, Liu C, Khan H, Zhang Z, Yang GY, Tang Y. Hypoxic Preconditioned Neural Stem Cell-Derived Extracellular Vesicles Contain Distinct Protein Cargo from Their Normal Counterparts. Curr Issues Mol Biol 2023; 45:1982-1997. [PMID: 36975497 PMCID: PMC10047917 DOI: 10.3390/cimb45030127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 02/21/2023] [Accepted: 02/27/2023] [Indexed: 03/05/2023] Open
Abstract
Hypoxic preconditioning has been demonstrated to increase the resistance of neural stem cells (NSCs) to hypoxic conditions, as well as to improve their capacity for differentiation and neurogenesis. Extracellular vesicles (EVs) have recently emerged as critical mediators of cell–cell communication, but their role in this hypoxic conditioning is presently unknown. Here, we demonstrated that three hours of hypoxic preconditioning triggers significant neural stem cell EV release. Proteomic profiling of EVs from normal and hypoxic preconditioned neural stem cells identified 20 proteins that were upregulated and 22 proteins that were downregulated after hypoxic preconditioning. We also found an upregulation of some of these proteins by qPCR, thus indicating differences also at the transcript level within the EVs. Among the upregulated proteins are CNP, Cyfip1, CASK, and TUBB5, which are well known to exhibit significant beneficial effects on neural stem cells. Thus, our results not only show a significant difference of protein cargo in EVs consequent to hypoxic exposure, but identify several candidate proteins that might play a pivotal role in the cell-to-cell mediated communication underlying neuronal differentiation, protection, maturation, and survival following exposure to hypoxic conditions.
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Wirth A, Ponimaskin E. Lipidation of small GTPase Cdc42 as regulator of its physiological and pathophysiological functions. Front Physiol 2023; 13:1088840. [PMID: 36699687 PMCID: PMC9868626 DOI: 10.3389/fphys.2022.1088840] [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: 11/03/2022] [Accepted: 12/26/2022] [Indexed: 01/11/2023] Open
Abstract
The protein cell division cycle 42 (Cdc42) is a small GTPase of the Rho family regulating a plethora of physiological functions in a tissue, cell and subcellular-specific manner via participating in multiple signaling pathways. Since the corresponding signaling hubs are mainly organized along the cellular membranes, cytosolic proteins like Cdc42 need to be properly targeted and held at the membrane. Here, lipid modifications come into play: Cdc42 can be associated with membranes by different lipid anchors including prenylation (Cdc42-prenyl) and palmitoylation (Cdc42-palm). While Cdc42-prenyl is ubiquitously expressed, Cdc42-palm splicing variant in mainly expressed in the brain. Mechanisms underlying Cdc42 lipidation as well as its regulation are the main topic of this review. Furthermore, we will discuss the functional importance of Cdc42 lipid modifications with the focus on the role of different lipids in regulating defined Cdc42 functions. Finally, we will provide an overview of the possible implementation of Cdc42 lipidation in pathological conditions and different diseases.
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