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Liang Y, Zhou Y, Xie D, Yin F, Luo X. Hypermethylation and low expression of FANCC involved in multi-walled carbon nanotube-induced toxicity on ARPE-19 cells. ENVIRONMENTAL RESEARCH 2024; 241:117619. [PMID: 37952855 DOI: 10.1016/j.envres.2023.117619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 11/07/2023] [Accepted: 11/07/2023] [Indexed: 11/14/2023]
Abstract
Multi-walled carbon nanotube (MWCNT) exposure was observed to cause damages on the viability of ocular cells, however, the underlying mechanisms remain not well understood. Epigenetic alterations that regulate gene expression have been identified as a major responsiveness to environmental challenge. Thus, the aim of this study was to screen methylation-regulated genes involved in MWCNT exposure. The Illumina Human Methylation 850 K array was employed to determine the genome-wide DNA methylation profile of human retinal pigment epithelial cell line (ARPE-19) exposed to 50% inhibition concentration of MWCNTs (100 μg/ml) for 24 h or without (n = 3 for each group). Then, the transcriptome data obtained by high-throughput RNA sequencing previously were integrated with DNA methylome to identify the overlapped genes. As a result, the integrative bioinformatics analysis identified that compared with controls, FA complementation group C (FANCC) was hypermethylated and downregulated in MWCNT-exposed ARPE-19 cells. Quantitative real-time polymerase chain reaction analysis confirmed the mRNA expression level of FANCC was significantly decreased following MWCNT treatment and the addition of DNA methylation inhibitor 5-Aza-deoxycytidine (10 μM) reversed this decrease. Pyrosequencing analysis further validated the hypermethylation status at the 5'-untranslated promoter region of FANCC (cg14583550) in MWCNT-exposed ARPE-19 cells. Protein-protein interaction network and function analyses predicted that FANCC may contribute to MWCNT-induced cytotoxicity by interacting with heat shock protein 90 beta family member 1 and then upregulating cytokine interleukin-6 and apoptosis biomarker caspase 3. In conclusion, the present study links the epigenetic modification of FANCC with the pathogenesis of MWCNT-induced retinal toxicity.
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Affiliation(s)
- Yunxia Liang
- College of Textile and Clothing Engineering, Soochow University, 199 Ren-Ai Road, Suzhou, 215123, China
| | - Yang Zhou
- School of Textile Science and Engineering/State Key Laboratory of New Textile Materials and Advanced Processing Technology, Wuhan Textile University, Wuhan, 430200, China.
| | - Dongli Xie
- College of Textile and Clothing Engineering, Soochow University, 199 Ren-Ai Road, Suzhou, 215123, China
| | - Fei Yin
- College of Textile and Clothing Engineering, Soochow University, 199 Ren-Ai Road, Suzhou, 215123, China
| | - Xiaogang Luo
- College of Textile and Clothing Engineering, Soochow University, 199 Ren-Ai Road, Suzhou, 215123, China.
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Zhuang J, Chen P, Wu Y, Luo Q, Wang Q, Chen S, Chen X, Jiang Z, Qiu J, Li Y, Yuan Z, Zhuang J. Brca1 Is Regulated by the Transcription Factor Gata3, and Its Silencing Promotes Neural Differentiation in Retinal Neurons. Int J Mol Sci 2022; 23:ijms232213860. [PMID: 36430332 PMCID: PMC9694312 DOI: 10.3390/ijms232213860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 10/29/2022] [Accepted: 11/03/2022] [Indexed: 11/12/2022] Open
Abstract
Previous studies have indicated that Brca1 (Breast cancer suppressor gene 1) plays an important role in neural development and degenerative diseases. However, the bioactivity and regulatory mechanism of Brca1 expression in retinal neurocytes remain unclear. In the present study, our data indicated that Brca1 maintains the state of neuronal precursor cells. Brca1 silencing induces differentiation in 661W cells. Nestin, a marker of precursor cells, was significantly decreased in parallel with Brca1 silencing in 661W cells, whereas Map2 (Microtubule associated protein 2), a marker of differentiated neurons, was significantly increased. Neurite outgrowth was increased by ~4.0-fold in Brca1-silenced cells. Moreover, DNA affinity purification assays and ChIP assays demonstrated that Gata3 (GATA binding protein 3) regulates Brca1 transcription in 661W cells. Silencing or overexpressing Gata3 could significantly regulate the expression of Brca1 and affect its promoter inducibility. Furthermore, the expression of Gata3 generally occurred in parallel with that of Brca1 in developing mouse retinas. Both Gata3 and Brca1 are expressed in the neonatal mouse retina but are developmentally silenced with age. Exogenous Gata3 significantly inhibited neural activity by decreasing synaptophysin and neurite outgrowth. Thus, this study demonstrated that Brca1 is transcriptionally regulated by Gata3. Brca1/Gata3 silencing is involved in neuronal differentiation and maturation.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Zhaohui Yuan
- Correspondence: (Z.Y.); (J.Z.); Tel.: +86-20-6667-8735 (J.Z.); Fax: +86-20-8733-3271 (J.Z.)
| | - Jing Zhuang
- Correspondence: (Z.Y.); (J.Z.); Tel.: +86-20-6667-8735 (J.Z.); Fax: +86-20-8733-3271 (J.Z.)
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3
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Yu N, Qiu J, Li K, Luo Q, Liu X, Yang Y, Jiang Z, He S, He A, Chen S, Chen X, Li Y, Ge J, Zhuang J, Yu K. Comparison of DNA stability and its related genes of neurons derived from induced pluripotent stem cells and primary retinal neurons. Cell Biol Int 2022; 46:1625-1636. [PMID: 35771585 DOI: 10.1002/cbin.11837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 04/05/2022] [Accepted: 05/28/2022] [Indexed: 11/12/2022]
Abstract
Maintaining DNA stability in induced pluripotent stem cells (iPSCs) and iPSCs-derived neurons is a challenge in their clinical application. In the present study, we compared DNA stability between primary retinal neurons and differentiated neurons. We found that the basal level of γ-H2AX phosphorylation, a specific marker of DNA breaks, was notably higher (~26-folds) in human iPSCs compared to iPSCs-derived neurons. However, iPSCs-derived neurons are more sensitive to UV treatment compared to primary rat retinal neurons (postnatal Day 1). UV treatment induced a significantly decreasing in the cell viability of iPSCs-derived neurons by ~76.1%, whereas ~20.8% in primary retinal neurons. After analyzing the expression levels of genes involved in DNA stability, such as Brca1, Ligase IV, Ku80, and Mre11, we found that Ku80 and its heterodimeric partner, Ku70 were positive in iPSCs-derived neurons. However, both Ku80 and Ku70 are not expressed in primary retinal neurons and cerebellar neurons. Similarly, both Ku80 and Ku70 are also expressed in 3D retinal organoids from human embryonic stem cells (ESCs), except for a few Map2-negative cells and the hyaloid vessels of mice E12.5 retinas. Hence, Ku80, and Ku70 are specifically expressed in stem cell-derived neurons. Moreover, using the Ku80 inhibitor Compound L, our data showed that Ku80 promotes the DNA stability and cell viability of iPSCs-derived neurons. Thus, our results demonstrated that iPSCs-, ESCs-derived neurons have specific characteristics of DNA stability. This study provides new insights into the neural differentiation of stem cells but might also warrant the future clinical application of stem cells in neurodegenerative diseases.
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Affiliation(s)
- Na Yu
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jin Qiu
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Kaijing Li
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Qian Luo
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xuan Liu
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Ying Yang
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Zihua Jiang
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Shengyu He
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Anqi He
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Shuilian Chen
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xi Chen
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Yan Li
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jian Ge
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jing Zhuang
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Keming Yu
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
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Lyons EL, Leone-Kabler S, Kovach AL, Thomas BF, Howlett AC. Cannabinoid receptor subtype influence on neuritogenesis in human SH-SY5Y cells. Mol Cell Neurosci 2020; 109:103566. [PMID: 33049367 DOI: 10.1016/j.mcn.2020.103566] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 10/01/2020] [Accepted: 10/06/2020] [Indexed: 10/23/2022] Open
Abstract
Human SH-SY5Y neuroblastoma cells stably expressing exogenous CB1 (CB1XS) or CB2 (CB2XS) receptors were developed to investigate endocannabinoid signaling in the extension of neuronal projections. Expression of cannabinoid receptors did not alter proliferation rate, viability, or apoptosis relative to parental SH-SY5Y. Transcripts for endogenous cannabinoid system enzymes (diacylglycerol lipase, monoacylglycerol lipase, α/β-hydrolase domain containing proteins 6 and 12, N-acyl phosphatidylethanolamine-phospholipase D, and fatty acid amide hydrolase) were not altered by CB1 or CB2 expression. Endocannabinoid ligands 2-arachidonoylglycerol (2-AG) and anandamide were quantitated in SH-SY5Y cells, and diacylglycerol lipase inhibitor tetrahydrolipstatin decreased 2-AG abundance by 90% but did not alter anandamide abundance. M3 muscarinic agonist oxotremorine M, and inhibitors of monoacylglycerol lipase and α/β hydrolase domain containing proteins 6 &12 increased 2-AG abundance. CB1 receptor expression increased lengths of short (<30 μm) and long (>30 μm) projections, and this effect was significantly reduced by tetrahydrolipstatin, indicative of stimulation by endogenously produced 2-AG. Pertussis toxin, Gβγ inhibitor gallein, and β-arrestin inhibitor barbadin did not significantly alter long projection length in CB1XS, but significantly reduced short projections, with gallein having the greatest inhibition. The rho kinase inhibitor Y27632 increased CB1 receptor-mediated long projection extension, indicative of actin cytoskeleton involvement. CB1 receptor expression increased GAP43 and ST8SIA2 mRNA and decreased ITGA1 mRNA, whereas CB2 receptor expression increased NCAM and SYT mRNA. We propose that basal endogenous production of 2-AG provides autocrine stimulation of CB1 receptor signaling through Gi/o, Gβγ, and β-arrestin mechanisms to promote neuritogenesis, and rho kinase influences process extension.
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Affiliation(s)
- Erica L Lyons
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, One Medical Center Blvd., Winston-Salem, NC 27157, USA.
| | - Sandra Leone-Kabler
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, One Medical Center Blvd., Winston-Salem, NC 27157, USA.
| | - Alexander L Kovach
- Discovery Sciences, RTI International, PO Box 12194, Research Triangle Park, NC 27709, USA.
| | - Brian F Thomas
- Discovery Sciences, RTI International, PO Box 12194, Research Triangle Park, NC 27709, USA.
| | - Allyn C Howlett
- Department of Physiology and Pharmacology, Wake Forest School of Medicine, One Medical Center Blvd., Winston-Salem, NC 27157, USA.
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Wu Y, Qiu J, Chen S, Chen X, Zhang J, Zhuang J, Liu S, Yang M, Zhou P, Chen H, Ge J, Yu K, Zhuang J. Crx Is Posttranscriptionally Regulated by Light Stimulation in Postnatal Rat Retina. Front Cell Dev Biol 2020; 8:174. [PMID: 32318566 PMCID: PMC7154164 DOI: 10.3389/fcell.2020.00174] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 03/02/2020] [Indexed: 11/13/2022] Open
Abstract
Cone rod homeobox (Crx) plays a key role at the center of a regulatory network that coordinates many pathways in the retina. Its abnormal expression induces retinal disorders. However, the underlying regulatory mechanism of Crx expression is not well defined. Here, we present data that show that the levels of Crx mRNA were inconsistent with that of Crx protein in primary retinal neurocytes cultured in light conditions. Crx protein levels were significantly higher (2.56-fold) in cells cultured in the dark than in cells cultured in light, whereas Crx mRNA was not changed in either type of cell. Moreover, the expression of Crx protein showed a significant light intensity-dependent decrease. Consistently, Crx downstream genes rhodopsin and arrestin also decreased in retinal neurocytes upon light exposure. Furthermore, Crx promoter activity assay performed in primary retinal neurocytes further indicated that light exposure and darkness did not affect its inducibility. In addition, the inconsistency between Crx mRNA and protein expression after light exposure was not observed in 661w cells transfected with plasmid pcDNA3.1-Crx, suggesting that the inconsistency between Crx mRNA and protein induced by light was specific to the endogenous Crx. More importantly, this observation was confirmed in vivo in postnatal day 15 (P15) retinas but not in adult retinas, further implicating that the posttranscriptional regulation mechanism may be involved in Crx expression in the developing retina. Therefore, our study sheds light on the mechanism of Crx expression in postnatal rat retina.
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Affiliation(s)
- Yihui Wu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jin Qiu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Shuilian Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xi Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jing Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jiejie Zhuang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Sian Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Meng Yang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Pan Zhou
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Haoting Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jian Ge
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Keming Yu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jing Zhuang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
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Chen D, Chao DL, Rocha L, Kolar M, Nguyen Huu VA, Krawczyk M, Dasyani M, Wang T, Jafari M, Jabari M, Ross KD, Saghatelian A, Hamilton BA, Zhang K, Skowronska‐Krawczyk D. The lipid elongation enzyme ELOVL2 is a molecular regulator of aging in the retina. Aging Cell 2020; 19:e13100. [PMID: 31943697 PMCID: PMC6996962 DOI: 10.1111/acel.13100] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 11/22/2019] [Accepted: 12/12/2019] [Indexed: 12/31/2022] Open
Abstract
Methylation of the regulatory region of the elongation of very‐long‐chain fatty acids‐like 2 (ELOVL2) gene, an enzyme involved in elongation of long‐chain polyunsaturated fatty acids, is one of the most robust biomarkers of human age, but the critical question of whether ELOVL2 plays a functional role in molecular aging has not been resolved. Here, we report that Elovl2 regulates age‐associated functional and anatomical aging in vivo, focusing on mouse retina, with direct relevance to age‐related eye diseases. We show that an age‐related decrease in Elovl2 expression is associated with increased DNA methylation of its promoter. Reversal of Elovl2 promoter hypermethylation in vivo through intravitreal injection of 5‐Aza‐2’‐deoxycytidine (5‐Aza‐dc) leads to increased Elovl2 expression and rescue of age‐related decline in visual function. Mice carrying a point mutation C234W that disrupts Elovl2‐specific enzymatic activity show electrophysiological characteristics of premature visual decline, as well as early appearance of autofluorescent deposits, well‐established markers of aging in the mouse retina. Finally, we find deposits underneath the retinal pigment epithelium in Elovl2 mutant mice, containing components found in human drusen, a pathologic hallmark of age related macular degeneration. These findings indicate that ELOVL2 activity regulates aging in mouse retina, provide a molecular link between polyunsaturated fatty acids elongation and visual function, and suggest novel therapeutic strategies for the treatment of age‐related eye diseases.
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Affiliation(s)
- Daniel Chen
- Shiley Eye Institute Viterbi Family Department of Ophthalmology University of California San Diego La Jolla CA USA
| | - Daniel L. Chao
- Shiley Eye Institute Viterbi Family Department of Ophthalmology University of California San Diego La Jolla CA USA
| | - Lorena Rocha
- Shiley Eye Institute Viterbi Family Department of Ophthalmology University of California San Diego La Jolla CA USA
| | - Matthew Kolar
- The Salk Institute for Biological StudiesClayton Foundation Laboratories for Peptide BiologyLa Jolla CA USA
| | - Viet Anh Nguyen Huu
- Shiley Eye Institute Viterbi Family Department of Ophthalmology University of California San Diego La Jolla CA USA
| | - Michal Krawczyk
- Shiley Eye Institute Viterbi Family Department of Ophthalmology University of California San Diego La Jolla CA USA
| | - Manish Dasyani
- Shiley Eye Institute Viterbi Family Department of Ophthalmology University of California San Diego La Jolla CA USA
| | - Tina Wang
- Department of Medicine University of California San Diego La Jolla CA USA
| | - Maryam Jafari
- Shiley Eye Institute Viterbi Family Department of Ophthalmology University of California San Diego La Jolla CA USA
| | - Mary Jabari
- Shiley Eye Institute Viterbi Family Department of Ophthalmology University of California San Diego La Jolla CA USA
| | - Kevin D. Ross
- Department of Cellular and Molecular Medicine University of California San Diego La Jolla CA USA
| | - Alan Saghatelian
- The Salk Institute for Biological StudiesClayton Foundation Laboratories for Peptide BiologyLa Jolla CA USA
| | - Bruce A. Hamilton
- Department of Cellular and Molecular Medicine University of California San Diego La Jolla CA USA
- Institute for Genomic Medicine University of California San Diego La Jolla CA USA
| | - Kang Zhang
- Shiley Eye Institute Viterbi Family Department of Ophthalmology University of California San Diego La Jolla CA USA
| | - Dorota Skowronska‐Krawczyk
- Shiley Eye Institute Viterbi Family Department of Ophthalmology University of California San Diego La Jolla CA USA
- Atkinson Laboratory for Regenerative Medicine University of California San Diego La Jolla CA USA
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Duraikannu A, Krishnan A, Chandrasekhar A, Zochodne DW. Beyond Trophic Factors: Exploiting the Intrinsic Regenerative Properties of Adult Neurons. Front Cell Neurosci 2019; 13:128. [PMID: 31024258 PMCID: PMC6460947 DOI: 10.3389/fncel.2019.00128] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 03/14/2019] [Indexed: 01/19/2023] Open
Abstract
Injuries and diseases of the peripheral nervous system (PNS) are common but frequently irreversible. It is often but mistakenly assumed that peripheral neuron regeneration is robust without a need to be improved or supported. However, axonal lesions, especially those involving proximal nerves rarely recover fully and injuries generally are complicated by slow and incomplete regeneration. Strategies to enhance the intrinsic growth properties of reluctant adult neurons offer an alternative approach to consider during regeneration. Since axons rarely regrow without an intimately partnered Schwann cell (SC), approaches to enhance SC plasticity carry along benefits to their axon partners. Direct targeting of molecules that inhibit growth cone plasticity can inform important regenerative strategies. A newer approach, a focus of our laboratory, exploits tumor suppressor molecules that normally dampen unconstrained growth. However several are also prominently expressed in stable adult neurons. During regeneration their ongoing expression “brakes” growth, whereas their inhibition and knockdown may enhance regrowth. Examples have included phosphatase and tensin homolog deleted on chromosome ten (PTEN), a tumor suppressor that inhibits PI3K/pAkt signaling, Rb1, the protein involved in retinoblastoma development, and adenomatous polyposis coli (APC), a tumor suppressor that inhibits β-Catenin transcriptional signaling and its translocation to the nucleus. The identification of several new targets to manipulate the plasticity of regenerating adult peripheral neurons is exciting. How they fit with canonical regeneration strategies and their feasibility require additional work. Newer forms of nonviral siRNA delivery may be approaches for molecular manipulation to improve regeneration.
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Affiliation(s)
- Arul Duraikannu
- Division of Neurology, Department of Medicine, and Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Anand Krishnan
- Division of Neurology, Department of Medicine, and Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Ambika Chandrasekhar
- Division of Neurology, Department of Medicine, and Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Douglas W Zochodne
- Division of Neurology, Department of Medicine, and Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
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Pietrzak J, Płoszaj T, Pułaski Ł, Robaszkiewicz A. EP300-HDAC1-SWI/SNF functional unit defines transcription of some DNA repair enzymes during differentiation of human macrophages. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2018; 1862:198-208. [PMID: 30414852 DOI: 10.1016/j.bbagrm.2018.10.019] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 10/17/2018] [Accepted: 10/31/2018] [Indexed: 01/31/2023]
Abstract
Differentiation of human macrophages predisposes these cells to numerous tasks, i.e. killing invading pathogens, and this entails the need for enhanced intracellular defences against stress, including conditions that may increase DNA damage. Our study shows that expression of DNA repair enzymes, such as PARP1, BRCA1 and XRCC1, are activated during macrophage development by the SWI/SNF chromatin remodelling complex, which serves as a histone acetylation sensor. It recognises and displaces epigenetically marked nucleosomes, thereby enabling transcription. Acetylation is controlled both in monocytes and macrophages by the co-operation of EP300 and HDAC1 activities. Differentiation modulates the activities of individual components of EP300-HDAC1-SWI/SNF functional unit and entails recruitment of PBAF to gene promoters. In monocytes, histone-deacetylated promoters of repressed PARP1, BRCA1 and XRCC1 respond only to HDAC inhibition, with an opening of the chromatin structure by BRM, whereas in macrophages both EP300 and HDAC1 contribute to the fine-tuning of nucleosomal acetylation, with HDAC1 remaining active and the balance of EP300 and HDAC1 activities controlling nucleosome eviction by BRG1-containing SWI/SNF. Since EP300-HDAC1-SWI/SNF operates at the level of gene promoters characterized simultaneously by the presence of E2F binding site(s) and CpG island(s), this allows cells to adjust PARP1, BRCA1 and XRCC1 transcription to the differentiation mode and to restart cell cycle progression. Thus, mutual interdependence between acetylase and deacetylase activities defines the acetylation-dependent code for regulation of histone density and gene transcription by SWI/SNF, notably on gene promoters of DNA repair enzymes.
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Affiliation(s)
- Julita Pietrzak
- Department of General Biophysics, Institute of Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland
| | - Tomasz Płoszaj
- Department of Clinical and Laboratory Genetics, Medical University of Lodz, Pomorska 251, 92-213 Lodz, Poland
| | - Łukasz Pułaski
- Laboratory of Transcriptional Regulation, Institute of Medical Biology PAS, Lodowa 106, 93-232 Lodz, Poland; Department of Molecular Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland
| | - Agnieszka Robaszkiewicz
- Department of General Biophysics, Institute of Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland.
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