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Ramirez P, Sun W, Kazempour Dehkordi S, Zare H, Fongang B, Bieniek KF, Frost B. Nanopore-based DNA long-read sequencing analysis of the aged human brain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.01.578450. [PMID: 38370753 PMCID: PMC10871260 DOI: 10.1101/2024.02.01.578450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Aging disrupts cellular processes such as DNA repair and epigenetic control, leading to a gradual buildup of genomic alterations that can have detrimental effects in post-mitotic cells. Genomic alterations in regions of the genome that are rich in repetitive sequences, often termed "dark loci," are difficult to resolve using traditional sequencing approaches. New long-read technologies offer promising avenues for exploration of previously inaccessible regions of the genome. Using nanopore-based long-read whole-genome sequencing of DNA extracted from aged 18 human brains, we identify previously unreported structural variants and methylation patterns within repetitive DNA, focusing on transposable elements ("jumping genes") as crucial sources of variation, particularly in dark loci. Our analyses reveal potential somatic insertion variants and provides DNA methylation frequencies for many retrotransposon families. We further demonstrate the utility of this technology for the study of these challenging genomic regions in brains affected by Alzheimer's disease and identify significant differences in DNA methylation in pathologically normal brains versus those affected by Alzheimer's disease. Highlighting the power of this approach, we discover specific polymorphic retrotransposons with altered DNA methylation patterns. These retrotransposon loci have the potential to contribute to pathology, warranting further investigation in Alzheimer's disease research. Taken together, our study provides the first long-read DNA sequencing-based analysis of retrotransposon sequences, structural variants, and DNA methylation in the aging brain affected with Alzheimer's disease neuropathology.
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Affiliation(s)
- Paulino Ramirez
- Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio, San Antonio, Texas
- Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases, University of Texas Health San Antonio, San Antonio, Texas
- Department of Cell Systems and Anatomy, University of Texas Health San Antonio, San Antonio, Texas
| | - Wenyan Sun
- Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio, San Antonio, Texas
- Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases, University of Texas Health San Antonio, San Antonio, Texas
- Department of Cell Systems and Anatomy, University of Texas Health San Antonio, San Antonio, Texas
- School of Pharmacy, University of Missouri-Kansas City, Kansas City, Missouri
| | - Shiva Kazempour Dehkordi
- Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases, University of Texas Health San Antonio, San Antonio, Texas
- Department of Cell Systems and Anatomy, University of Texas Health San Antonio, San Antonio, Texas
| | - Habil Zare
- Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases, University of Texas Health San Antonio, San Antonio, Texas
- Department of Cell Systems and Anatomy, University of Texas Health San Antonio, San Antonio, Texas
| | - Bernard Fongang
- Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases, University of Texas Health San Antonio, San Antonio, Texas
- Department of Biochemistry & Structural Biology, University of Texas Health San Antonio, San Antonio, Texas
| | - Kevin F. Bieniek
- Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases, University of Texas Health San Antonio, San Antonio, Texas
- Department of Pathology, University of Texas Health San Antonio, San Antonio, Texas
| | - Bess Frost
- Barshop Institute for Longevity and Aging Studies, University of Texas Health San Antonio, San Antonio, Texas
- Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases, University of Texas Health San Antonio, San Antonio, Texas
- Department of Cell Systems and Anatomy, University of Texas Health San Antonio, San Antonio, Texas
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Shin W, Mun S, Han K. Human Endogenous Retrovirus-K (HML-2)-Related Genetic Variation: Human Genome Diversity and Disease. Genes (Basel) 2023; 14:2150. [PMID: 38136972 PMCID: PMC10742618 DOI: 10.3390/genes14122150] [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: 10/25/2023] [Revised: 11/23/2023] [Accepted: 11/26/2023] [Indexed: 12/24/2023] Open
Abstract
Human endogenous retroviruses (HERVs) comprise a significant portion of the human genome, making up roughly 8%, a notable comparison to the 2-3% represented by coding sequences. Numerous studies have underscored the critical role and importance of HERVs, highlighting their diverse and extensive influence on the evolution of the human genome and establishing their complex correlation with various diseases. Among HERVs, the HERV-K (HML-2) subfamily has recently attracted significant attention, integrating into the human genome after the divergence between humans and chimpanzees. Its insertion in the human genome has received considerable attention due to its structural and functional characteristics and the time of insertion. Originating from ancient exogenous retroviruses, these elements succeeded in infecting germ cells, enabling vertical transmission and existing as proviruses within the genome. Remarkably, these sequences have retained the capacity to form complete viral sequences, exhibiting activity in transcription and translation. The HERV-K (HML-2) subfamily is the subject of active debate about its potential positive or negative effects on human genome evolution and various pathologies. This review summarizes the variation, regulation, and diseases in human genome evolution arising from the influence of HERV-K (HML-2).
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Affiliation(s)
- Wonseok Shin
- NGS Clinical Laboratory, Division of Cancer Research, Dankook University Hospital, Cheonan 31116, Republic of Korea;
- Smart Animal Bio Institute, Dankook University, Cheonan 31116, Republic of Korea;
| | - Seyoung Mun
- Smart Animal Bio Institute, Dankook University, Cheonan 31116, Republic of Korea;
- College of Science & Technology, Dankook University, Cheonan 31116, Republic of Korea
- Center for Bio-Medical Engineering Core Facility, Dankook University, Cheonan 31116, Republic of Korea
| | - Kyudong Han
- Smart Animal Bio Institute, Dankook University, Cheonan 31116, Republic of Korea;
- Center for Bio-Medical Engineering Core Facility, Dankook University, Cheonan 31116, Republic of Korea
- Department of Microbiology, College of Science & Technology, Dankook University, Cheonan 31116, Republic of Korea
- Department of Bioconvergence Engineering, Dankook University, Yongin 16890, Republic of Korea
- R&D Center, HuNBiome Co., Ltd., Seoul 08507, Republic of Korea
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Hosseiniporgham S, Sechi LA. Anti-HERV-K Drugs and Vaccines, Possible Therapies against Tumors. Vaccines (Basel) 2023; 11:vaccines11040751. [PMID: 37112663 PMCID: PMC10144246 DOI: 10.3390/vaccines11040751] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 03/20/2023] [Accepted: 03/21/2023] [Indexed: 03/31/2023] Open
Abstract
The footprint of human endogenous retroviruses (HERV), specifically HERV-K, has been found in malignancies, such as melanoma, teratocarcinoma, osteosarcoma, breast cancer, lymphoma, and ovary and prostate cancers. HERV-K is characterized as the most biologically active HERV due to possession of open reading frames (ORF) for all Gag, Pol, and Env genes, which enables it to be more infective and obstructive towards specific cell lines and other exogenous viruses, respectively. Some factors might contribute to carcinogenicity and at least one of them has been recognized in various tumors, including overexpression/methylation of long interspersed nuclear element 1 (LINE-1), HERV-K Gag, and Env genes themselves plus their transcripts and protein products, and HERV-K reverse transcriptase (RT). Therapies effective for HERV-K-associated tumors mostly target invasive autoimmune responses or growth of tumors through suppression of HERV-K Gag or Env protein and RT. To design new therapeutic options, more studies are needed to better understand whether HERV-K and its products (Gag/Env transcripts and HERV-K proteins/RT) are the initiators of tumor formation or just the disorder’s developers. Accordingly, this review aims to present evidence that highlights the association between HERV-K and tumorigenicity and introduces some of the available or potential therapies against HERV-K-induced tumors.
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