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Ng RR, Lin Z, Zhang Y, Ti SC, Javed A, Wong JWH, Fang Q, Leung JWC, Tang AHN, Huen MSY. R-loop resolution by ARIP4 helicase promotes androgen-mediated transcription induction. SCIENCE ADVANCES 2024; 10:eadm9577. [PMID: 39028815 PMCID: PMC11259169 DOI: 10.1126/sciadv.adm9577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 06/14/2024] [Indexed: 07/21/2024]
Abstract
Pausing of RNA polymerase II (Pol II) at transcription start sites (TSSs) primes target genes for productive elongation. Coincidentally, DNA double-strand breaks (DSBs) enrich at highly transcribed and Pol II-paused genes, although their interplay remains undefined. Using androgen receptor (AR) signaling as a model, we have uncovered AR-interacting protein 4 (ARIP4) helicase as a driver of androgen-dependent transcription induction. Chromatin immunoprecipitation sequencing analysis revealed that ARIP4 preferentially co-occupies TSSs with paused Pol II. Moreover, we found that ARIP4 complexes with topoisomerase II beta and mediates transient DSB formation upon hormone stimulation. Accordingly, ARIP4 deficiency compromised release of paused Pol II and resulted in R-loop accumulation at a panel of highly transcribed AR target genes. Last, we showed that ARIP4 binds and unwinds R-loops in vitro and that its expression positively correlates with prostate cancer progression. We propose that androgen stimulation triggers ARIP4-mediated unwinding of R-loops at TSSs, enforcing Pol II pause release to effectively drive an androgen-dependent expression program.
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Affiliation(s)
- Raissa Regina Ng
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong S.A.R
| | - Zhongyang Lin
- Department of Biology, Shantou University, Shantou, Guangdong, China
| | - Yanmin Zhang
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong S.A.R
| | - Shih Chieh Ti
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong S.A.R
| | - Asif Javed
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong S.A.R
| | - Jason Wing Hon Wong
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong S.A.R
| | - Qingming Fang
- Department of Biochemistry and Structural Biology and Greehey Children’s Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Justin Wai Chung Leung
- Department of Radiation Oncology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Alex Hin Ning Tang
- Department of Pathology, School of Clinical Medicine LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong S.A.R
| | - Michael Shing Yan Huen
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong S.A.R
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Pokfulam, Hong Kong S.A.R
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Guo W, Qu Y, Yu Y, Li X, Liang Z, Wang Z, Hu T, Zhou S. DKK2 promotes the progression of oral squamous cell carcinoma through the PI3K/AKT signaling pathway. Aging (Albany NY) 2024; 16:9204-9215. [PMID: 38795388 PMCID: PMC11164507 DOI: 10.18632/aging.205864] [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: 11/29/2023] [Accepted: 03/29/2024] [Indexed: 05/27/2024]
Abstract
OBJECTIVE This study aimed to investigate the impact of Dickkopf 2 (DKK2) on the progression of oral squamous cell carcinoma (OSCC) and explore its role in the PI3K/AKT signaling transduction pathway. MATERIALS AND METHODS The study initially examined the expression of the DKK2 gene in OSCC tissues and normal tissues. Simultaneously, the expression of DKK2 in HOK cells and OSCC cells was verified, and changes in DKK2 expression under hypoxic conditions were detected. DKK2 overexpression and knockdown were performed in SCC-15 and CAL-27 cells. Subsequently, the effects of DKK2 on the proliferation, migration and invasion of OSCC were detected. Western blotting was employed to detect the expression of key proteins in the DKK2/PI3K/AKT signaling axis before and after transfection, and further explore the relevant molecular mechanisms. RESULTS Compared to normal tissues, DKK2 expression was elevated in OSCC tissues. The expression of DKK2 in the SCC-15 and CAL-27 cell lines was higher than that in HOK cells, and hypoxic conditions could promote DKK2 expression. DKK2 overexpression promoted cell proliferation, migration, and invasion, while DKK2 knockdown inhibited these processes. DKK2 overexpression activated the PI3K/AKT pathway, while DKK2 knockdown suppressed this pathway. CONCLUSION This study suggests that hypoxic conditions enhance the expression of DKK2 in OSCC. DKK2 regulates the proliferation, migration, and invasion of OSCC through the PI3K/AKT signaling pathway.
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Affiliation(s)
- Wenbo Guo
- Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Harbin Medical University, School of Stomatology, Harbin 150001, Heilongjiang, China
- Key Laboratory of Hepatosplenic Surgery, Ministry of Education, Harbin 150001, Heilongjiang, China
| | - Yun Qu
- Department of Orthodontics, The Second Affiliated Hospital of Harbin Medical University, Harbin 150001, Heilongjiang, China
| | - Yang Yu
- Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Harbin Medical University, School of Stomatology, Harbin 150001, Heilongjiang, China
| | - Xueming Li
- Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Harbin Medical University, School of Stomatology, Harbin 150001, Heilongjiang, China
| | - Zhuang Liang
- Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Harbin Medical University, School of Stomatology, Harbin 150001, Heilongjiang, China
| | - Zhaoqi Wang
- Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Harbin Medical University, School of Stomatology, Harbin 150001, Heilongjiang, China
| | - Tenglong Hu
- Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Harbin Medical University, School of Stomatology, Harbin 150001, Heilongjiang, China
| | - Shan Zhou
- Department of Orthodontics, The Second Affiliated Hospital of Harbin Medical University, Harbin 150001, Heilongjiang, China
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Duxbury EML, Carlsson H, Kimberley A, Ridge Y, Johnson K, Maklakov AA. Reduced insulin/IGF-1 signalling upregulates two anti-viral immune pathways, decreases viral load and increases survival under viral infection in C. elegans. GeroScience 2024:10.1007/s11357-024-01147-7. [PMID: 38589671 DOI: 10.1007/s11357-024-01147-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 03/25/2024] [Indexed: 04/10/2024] Open
Abstract
Reduced insulin/IGF-1 signalling (rIIS) improves survival across diverse taxa and there is a growing interest in its role in regulating immune function. Whilst rIIS can improve anti-bacterial resistance, the consequences for anti-viral immunity are yet to be systematically examined. Here, we show that rIIS in adult Caenorhabditis elegans increases the expression of key genes in two different anti-viral immunity pathways, whilst reducing viral load in old age, increasing survival and reducing rate-of-senescence under infection by naturally occurring positive-sense single-stranded RNA Orsay virus. We found that both drh-1 in the anti-viral RNA interference (RNAi) pathway and cde-1 in the terminal uridylation-based degradation of viral RNA pathway were upregulated in early adulthood under rIIS and increased anti-viral resistance was not associated with reproductive costs. Remarkably, rIIS increased anti-viral gene expression only in infected worms, potentially to curb the costs of constitutively upregulated immunity. RNA viruses are found across taxa from plants to mammals and we demonstrate a novel role for rIIS in regulating resistance to viral infection. We therefore highlight this evolutionarily conserved signalling pathway as a promising therapeutic target to improve anti-viral immunity.
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Affiliation(s)
| | - Hanne Carlsson
- School of Biological Sciences, University of East Anglia, Norwich, UK
| | - Annabel Kimberley
- School of Biological Sciences, University of East Anglia, Norwich, UK
| | - Yvonne Ridge
- School of Biological Sciences, University of East Anglia, Norwich, UK
| | - Katie Johnson
- School of Biological Sciences, University of East Anglia, Norwich, UK
| | - Alexei A Maklakov
- School of Biological Sciences, University of East Anglia, Norwich, UK
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Tse-Kang S, Wani KA, Peterson ND, Page A, Pukkila-Worley R. Activation of intestinal immunity by pathogen effector-triggered aggregation of lysosomal TIR-1/SARM1. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.04.569946. [PMID: 38106043 PMCID: PMC10723332 DOI: 10.1101/2023.12.04.569946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
TIR-domain proteins with enzymatic activity are essential for immunity in plants, animals, and bacteria. However, it is not known how these proteins function in pathogen sensing in animals. We discovered that a TIR-domain protein (TIR-1/SARM1) is strategically expressed on the membranes of a lysosomal sub-compartment, which enables intestinal epithelial cells in the nematode C. elegans to survey for pathogen effector-triggered host damage. We showed that a redox active virulence effector secreted by the bacterial pathogen Pseudomonas aeruginosa alkalinized and condensed a specific subset of lysosomes by inducing intracellular oxidative stress. Concentration of TIR-1/SARM1 on the surface of these organelles triggered its multimerization, which engages its intrinsic NADase activity, to activate the p38 innate immune pathway and protect the host against microbial intoxication. Thus, lysosomal TIR-1/SARM1 is a sensor for oxidative stress induced by pathogenic bacteria to activate metazoan intestinal immunity.
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Tran TD, Luallen RJ. An organismal understanding of C. elegans innate immune responses, from pathogen recognition to multigenerational resistance. Semin Cell Dev Biol 2024; 154:77-84. [PMID: 36966075 PMCID: PMC10517082 DOI: 10.1016/j.semcdb.2023.03.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 03/05/2023] [Accepted: 03/14/2023] [Indexed: 03/27/2023]
Abstract
The nematode Caenorhabditis elegans has been a model for studying infection since the early 2000s and many major discoveries have been made regarding its innate immune responses. C. elegans has been found to utilize some key conserved aspects of immune responses and signaling, but new interesting features of innate immunity have also been discovered in the organism that might have broader implications in higher eukaryotes such as mammals. Some of the distinctive features of C. elegans innate immunity involve the mechanisms this bacterivore uses to detect infection and mount specific immune responses to different pathogens, despite lacking putative orthologs of many important innate immune components, including cellular immunity, the inflammasome, complement, or melanization. Even when orthologs of known immune factors exist, there appears to be an absence of canonical functions, most notably the lack of pattern recognition by its sole Toll-like receptor. Instead, recent research suggests that C. elegans senses infection by specific pathogens through contextual information, including unique products produced by the pathogen or infection-induced disruption of host physiology, similar to the proposed detection of patterns of pathogenesis in mammalian systems. Interestingly, C. elegans can also transfer information of past infection to their progeny, providing robust protection for their offspring in face of persisting pathogens, in part through the RNAi pathway as well as potential new mechanisms that remain to be elucidated. Altogether, some of these strategies employed by C. elegans share key conceptual features with vertebrate adaptive immunity, as the animal can differentiate specific microbial features, as well as propagate a form of immune memory to their offspring.
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Affiliation(s)
- Tuan D Tran
- Department of Biology San Diego State University, 5500 Campanile Dr., San Diego, CA 92182, USA
| | - Robert J Luallen
- Department of Biology San Diego State University, 5500 Campanile Dr., San Diego, CA 92182, USA.
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