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Cheong HC, Sulaiman S, Looi CY, Chang LY, Wong WF. Chlamydia Infection Remodels Host Cell Mitochondria to Alter Energy Metabolism and Subvert Apoptosis. Microorganisms 2023; 11:1382. [PMID: 37374883 DOI: 10.3390/microorganisms11061382] [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: 04/07/2023] [Revised: 05/18/2023] [Accepted: 05/19/2023] [Indexed: 06/29/2023] Open
Abstract
Chlamydia infection represents an important cause for concern for public health worldwide. Chlamydial infection of the genital tract in females is mostly asymptomatic at the early stage, often manifesting as mucopurulent cervicitis, urethritis, and salpingitis at the later stage; it has been associated with female infertility, spontaneous abortion, ectopic pregnancy, and cervical cancer. As an obligate intracellular bacterium, Chlamydia depends heavily on host cells for nutrient acquisition, energy production, and cell propagation. The current review discusses various strategies utilized by Chlamydia in manipulating the cell metabolism to benefit bacterial propagation and survival through close interaction with the host cell mitochondrial and apoptotic pathway molecules.
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Affiliation(s)
- Heng Choon Cheong
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Sofiah Sulaiman
- Department of Obstetrics and Gynaecology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Chung Yeng Looi
- School of Biosciences, Faculty of Health and Medical Sciences, Taylor's University, Subang Jaya 47500, Selangor, Malaysia
| | - Li-Yen Chang
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Won Fen Wong
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
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Teulière J, Bernard C, Bapteste E. Interspecific interactions that affect ageing: Age-distorters manipulate host ageing to their own evolutionary benefits. Ageing Res Rev 2021; 70:101375. [PMID: 34082078 DOI: 10.1016/j.arr.2021.101375] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 05/22/2021] [Accepted: 05/26/2021] [Indexed: 02/07/2023]
Abstract
Genetic causes for ageing are traditionally investigated within a species. Yet, the lifecycles of many organisms intersect. Additional evolutionary and genetic causes of ageing, external to a focal species/organism, may thus be overlooked. Here, we introduce the phrase and concept of age-distorters and its evidence. Age-distorters carry ageing interfering genes, used to manipulate the biological age of other entities upon which the reproduction of age-distorters relies, e.g. age-distorters bias the reproduction/maintenance trade-offs of cells/organisms for their own evolutionary interests. Candidate age-distorters include viruses, parasites and symbionts, operating through specific, genetically encoded interferences resulting from co-evolution and arms race between manipulative non-kins and manipulable species. This interference results in organismal ageing when age-distorters prompt manipulated organisms to favor their reproduction at the expense of their maintenance, turning these hosts into expanded disposable soma. By relying on reproduction/maintenance trade-offs affecting disposable entities, which are left ageing to the reproductive benefit of other physically connected lineages with conflicting evolutionary interests, the concept of age-distorters expands the logic of the Disposable Soma theory beyond species with fixed germen/soma distinctions. Moreover, acknowledging age-distorters as external sources of mutation accumulation and antagonistic pleiotropic genes expands the scope of the mutation accumulation and of the antagonistic pleiotropy theories.
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Affiliation(s)
- Jérôme Teulière
- Institut de Systématique, Evolution, Biodiversité (ISYEB), Sorbonne Université, CNRS, Museum National d'Histoire Naturelle, EPHE, Université des Antilles, Paris, France
| | - Charles Bernard
- Institut de Systématique, Evolution, Biodiversité (ISYEB), Sorbonne Université, CNRS, Museum National d'Histoire Naturelle, EPHE, Université des Antilles, Paris, France
| | - Eric Bapteste
- Institut de Systématique, Evolution, Biodiversité (ISYEB), Sorbonne Université, CNRS, Museum National d'Histoire Naturelle, EPHE, Université des Antilles, Paris, France.
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Fernandes SG, Dsouza R, Khattar E. External environmental agents influence telomere length and telomerase activity by modulating internal cellular processes: Implications in human aging. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2021; 85:103633. [PMID: 33711516 DOI: 10.1016/j.etap.2021.103633] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 01/30/2021] [Accepted: 03/05/2021] [Indexed: 06/12/2023]
Abstract
External environment affects cellular physiological processes and impact the stability of our genome. The most important structural components of our linear chromosomes which endure the impact by these agents, are the chromosomal ends called telomeres. Telomeres preserve the integrity of our genome by preventing end to end fusions and telomeric loss through by inhibiting DNA damage response (DDR) activation. This is accomplished by the presence of a six membered shelterin complex at telomeres. Further, telomeres cannot be replicated by normal DNA polymerase and require a special enzyme called telomerase which is expressed only in stem cells, few immune cells and germ cells. Telomeres are rich in guanine content and thus become extremely prone to damage arising due to physiological processes like oxidative stress and inflammation. External environmental factors which includes various physical, biological and chemical agents also affect telomere homeostasis by increasing oxidative stress and inflammation. In the present review, we highlight the effect of these external factors on telomerase activity and telomere length. We also discuss how the external agents affect the physiological processes, thus modulating telomere stability. Further, we describe its implication in the development of aging and its related pathologies.
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Affiliation(s)
- Stina George Fernandes
- Sunandan Divatia School of Science, SVKM's NMIMS (Deemed to be University), Vile Parle West, Mumbai, 400056, India
| | - Rebecca Dsouza
- Sunandan Divatia School of Science, SVKM's NMIMS (Deemed to be University), Vile Parle West, Mumbai, 400056, India
| | - Ekta Khattar
- Sunandan Divatia School of Science, SVKM's NMIMS (Deemed to be University), Vile Parle West, Mumbai, 400056, India.
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Yang X, Siddique A, Khan AA, Wang Q, Malik A, Jan AT, Rudayni HA, Chaudhary AA, Khan S. Chlamydia Trachomatis Infection: Their potential implication in the Etiology of Cervical Cancer. J Cancer 2021; 12:4891-4900. [PMID: 34234859 PMCID: PMC8247366 DOI: 10.7150/jca.58582] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Accepted: 05/13/2021] [Indexed: 12/12/2022] Open
Abstract
Pathogenic bacterial strains can alter the normal function of cells and induce different levels of inflammatory responses that are connected to the development of different diseases, such as tuberculosis, diarrhea, cancer etc. Chlamydia trachomatis (C. trachomatis) is an intracellular obligate gram-negative bacterium which has been connected with the cervical cancer etiology. Nevertheless, establishment of causality and the underlying mechanisms of carcinogenesis of cervical cancer associated with C. trachomatis remain unclear. Studies reveal the existence of C. trachomatis in cervical cancer patients. The DNA repair pathways including mismatch repair, nucleotide excision, and base excision are vital in the abatement of accumulated mutations that can direct to the process of carcinogenesis. C. trachomatis recruits DDR proteins away from sites of DNA damage and, in this way, impedes the DDR. Therefore, by disturbing host cell-cycle control, chromatin and DDR repair, C. trachomatis makes a situation favorable for malignant transformation. Inflammation originated due to infection directs over production of reactive oxygen species (ROS) and consequent oxidative DNA damage. This review may aid our current understanding of the etiology of cervical cancer in C. trachomatis-infected patients.
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Affiliation(s)
- Xingju Yang
- Department of Nursing, Jinan People's Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 271199, China
| | - Anam Siddique
- Department of Biosciences, Shri Ram Group of College (SRGC), Muzaffarnagar 251001, India
| | - Abdul Arif Khan
- Division of Microbiology, Indian Council of Medical Research-National AIDS Research Institute, Pune, Maharashtra, India
| | - Qian Wang
- Department of Obstetrics and Gynecology, Jinan Fifth People's Hospital, Jinan, Shandong, 250022, China
| | - Abdul Malik
- Department of Pharmaceutics, College of Pharmacy, P.O. Box 2457, King Saud University, Riyadh 11451, Saudi Arabia
| | - Arif Tasleem Jan
- School of Biosciences and Biotechnology, Baba Ghulam Shah Badshah University, Rajouri 185236, India
| | - Hassan Ahmed Rudayni
- Department of Biology, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh 11623, Saudi Arabia
| | - Anis Ahmad Chaudhary
- Department of Biology, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh 11623, Saudi Arabia
| | - Shahanavaj Khan
- Department of Biosciences, Shri Ram Group of College (SRGC), Muzaffarnagar 251001, India
- Department of Pharmaceutics, College of Pharmacy, P.O. Box 2457, King Saud University, Riyadh 11451, Saudi Arabia
- Department of Health Sciences, Novel Global Community Educational Foundation, Australia
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Poli-Neto OB, Carlos D, Favaretto A, Rosa-E-Silva JC, Meola J, Tiezzi D. Eutopic endometrium from women with endometriosis and chlamydial endometritis share immunological cell types and DNA repair imbalance: A transcriptome meta-analytical perspective. J Reprod Immunol 2021; 145:103307. [PMID: 33725527 DOI: 10.1016/j.jri.2021.103307] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 02/03/2021] [Accepted: 03/01/2021] [Indexed: 12/21/2022]
Abstract
The aim of this study was to identify the key similarities between the eutopic endometrium of women with endometriosis and chlamydia-induced endometritis taking into account tissue microenvironment heterogeneity, transcript gene profile, and enriched pathways. A meta-analysis of whole transcriptome microarrays was performed using publicly available data, including samples containing both glandular and stromal endometrial components. Control samples were obtained from women without any reported pathological condition. Only samples obtained during the proliferative menstrual phase were included. Cellular tissue heterogeneity was predicted using a method that integrates gene set enrichment and deconvolution approaches. The batch effect was estimated by principal variant component analysis and removed using an empirical Bayes method. Differentially expressed genes were identified using an adjusted p-value < 0.05 and fold change = 1.5. The protein-protein interaction network was built using the STRING database and interaction score over 400. The Molecular Signatures Database was used to analyse the functional enrichment analysis. Both conditions showed similarities in cell types in the microenvironment, particularly CD4+ and CD8+ Tem cells, NKT cells, Th2 cells, basophils, and eosinophils. With regards to the regulation of cellular senescence and DNA integrity/damage checkpoint, which are commonly enriched pathways, 21 genes were down-regulated and directly related to DNA repair. Compared to the endometriosis samples, some chlamydial endometritis samples presented a lack of enriched immune pathways. Our results suggest that both conditions show similar distributions of microenvironment cell types, the downregulation of genes involved in DNA repair and cell cycle control, and pathways involved in immune response evasion.
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Affiliation(s)
- Omero Benedicto Poli-Neto
- Gynecological and Obstetrics Department, Ribeirão Preto Medical School of the University of São Paulo, Ribeirão Preto, 14049-900, SP, Brazil.
| | - Daniela Carlos
- Biochemistry and Immunology Department, Ribeirão Preto Medical School of the University of São Paulo, Ribeirão Preto, SP, 14049-900, Brazil
| | - Aureo Favaretto
- Gynecological and Obstetrics Department, Ribeirão Preto Medical School of the University of São Paulo, Ribeirão Preto, 14049-900, SP, Brazil
| | - Julio Cesar Rosa-E-Silva
- Gynecological and Obstetrics Department, Ribeirão Preto Medical School of the University of São Paulo, Ribeirão Preto, 14049-900, SP, Brazil
| | - Juliana Meola
- Gynecological and Obstetrics Department, Ribeirão Preto Medical School of the University of São Paulo, Ribeirão Preto, 14049-900, SP, Brazil
| | - Daniel Tiezzi
- Gynecological and Obstetrics Department, Ribeirão Preto Medical School of the University of São Paulo, Ribeirão Preto, 14049-900, SP, Brazil
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Humphreys D, ElGhazaly M, Frisan T. Senescence and Host-Pathogen Interactions. Cells 2020; 9:cells9071747. [PMID: 32708331 PMCID: PMC7409240 DOI: 10.3390/cells9071747] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 07/20/2020] [Accepted: 07/20/2020] [Indexed: 12/14/2022] Open
Abstract
Damage to our genomes triggers cellular senescence characterised by stable cell cycle arrest and a pro-inflammatory secretome that prevents the unrestricted growth of cells with pathological potential. In this way, senescence can be considered a powerful innate defence against cancer and viral infection. However, damage accumulated during ageing increases the number of senescent cells and this contributes to the chronic inflammation and deregulation of the immune function, which increases susceptibility to infectious disease in ageing organisms. Bacterial and viral pathogens are masters of exploiting weak points to establish infection and cause devastating diseases. This review considers the emerging importance of senescence in the host-pathogen interaction: we discuss the pathogen exploitation of ageing cells and senescence as a novel hijack target of bacterial pathogens that deploys senescence-inducing toxins to promote infection. The persistent induction of senescence by pathogens, mediated directly through virulence determinants or indirectly through inflammation and chronic infection, also contributes to age-related pathologies such as cancer. This review highlights the dichotomous role of senescence in infection: an innate defence that is exploited by pathogens to cause disease.
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Affiliation(s)
- Daniel Humphreys
- Department of Biomedical Science, University of Sheffield, Sheffield S10 2TN, UK;
- Correspondence: (D.H.); (T.F.)
| | - Mohamed ElGhazaly
- Department of Biomedical Science, University of Sheffield, Sheffield S10 2TN, UK;
| | - Teresa Frisan
- Department of Molecular Biology, Umeå University, 901 87 Umeå, Sweden
- Umeå Centre for Microbial Research (UCMR), Umeå University, 901 87 Umeå, Sweden
- Correspondence: (D.H.); (T.F.)
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Fuchs G, Dianova E, Patel S, Kamanda S, Verma RP. Sirenomelia and maternal chlamydia trachomatis infection: a case report and review. Fetal Pediatr Pathol 2019; 38:524-533. [PMID: 31213098 DOI: 10.1080/15513815.2019.1627623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Background: Sirenomelia is a lethal congenital anomaly, presenting with fusion of lower extremities and malformed perineum. The pathogenesis is unclear, and "defective blastogenesis" is the proposed mechanism. Chlamydia trachomatis (CT) is an obligate intracellular pathogen which reportedly invades placenta and may result in fetal demise. It has documented cytopathogenic effects, specifically, cellular disruption, tissue dysgenesis, and genomic instability.Case report: An infant with sirenomelia was born as a product of 30 weeks of pregnancy, which was normal except for a persistent maternal CT infection. The infant expired shortly after birth.Conclusion: Fetal invasion by CT, conceivably, may induce structural anomalies, such as sirenomelia by virtue of its cytopathic effects. We intend to draw attention to such a possibility by reporting this case. This association, however, is speculative and more cases of sirenomelia with CT positive mothers need to be described in order to make definite conclusions about such a relationship.
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Affiliation(s)
| | | | - Sunny Patel
- Nassau University Medical Center, East Meadow, NY, USA
| | - Sonia Kamanda
- Cohen Children Medical Center, New Hyde Park, NY, USA
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Gulve N, Rudel T. Chlamydia trachomatis and human herpesvirus 6 infections in ovarian cancer-Casual or causal? PLoS Pathog 2019; 15:e1008055. [PMID: 31697787 PMCID: PMC6837282 DOI: 10.1371/journal.ppat.1008055] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Affiliation(s)
- Nitish Gulve
- Department of Microbiology, Biocenter, University of Wuerzburg, Wuerzburg, Germany
| | - Thomas Rudel
- Department of Microbiology, Biocenter, University of Wuerzburg, Wuerzburg, Germany
- * E-mail:
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Affiliation(s)
- Sidhant Jain
- Department of Zoology, University of Delhi, North Campus, New Delhi, India
| | - Madhumita Sengupta
- Department of Zoology, University of Delhi, North Campus, New Delhi, India
| | - Pooja Jain
- Department of Obstetrics and Gynaecology, Bhagwati Hospital, New Delhi, India
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Mi Y, Gurumurthy RK, Zadora PK, Meyer TF, Chumduri C. Chlamydia trachomatis Inhibits Homologous Recombination Repair of DNA Breaks by Interfering with PP2A Signaling. mBio 2018; 9:e01465-18. [PMID: 30401777 PMCID: PMC6222135 DOI: 10.1128/mbio.01465-18] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 10/01/2018] [Indexed: 12/05/2022] Open
Abstract
Cervical and ovarian cancers exhibit characteristic mutational signatures that are reminiscent of mutational processes, including defective homologous recombination (HR) repair. How these mutational processes are initiated during carcinogenesis is largely unclear. Chlamydia trachomatis infections are epidemiologically associated with cervical and ovarian cancers. Previously, we showed that C. trachomatis induces DNA double-strand breaks (DSBs) but suppresses Ataxia-telangiectasia mutated (ATM) activation and cell cycle checkpoints. The mechanisms by which ATM regulation is modulated and its consequences for the repair pathway in C. trachomatis-infected cells remain unknown. Here, we found that Chlamydia bacteria interfere with the usual response of PP2A to DSBs. As a result, PP2A activity remains high, as the level of inhibitory phosphorylation at Y307 remains unchanged following C. trachomatis-induced DSBs. Protein-protein interaction analysis revealed that C. trachomatis facilitates persistent interactions of PP2A with ATM, thus suppressing ATM activation. This correlated with a remarkable lack of homologous recombination (HR) repair in C. trachomatis-infected cells. Chemical inhibition of PP2A activity in infected cells released ATM from PP2A, resulting in ATM phosphorylation. Activated ATM was then recruited to DSBs and initiated downstream signaling, including phosphorylation of MRE11 and NBS1 and checkpoint kinase 2 (Chk2)-mediated activation of the G2/M cell cycle checkpoint in C. trachomatis-infected cells. Further, PP2A inhibition led to the restoration of C. trachomatis-suppressed HR DNA repair function. Taking the data together, this study revealed that C. trachomatis modulates PP2A signaling to suppress ATM activation to prevent cell cycle arrest, thus contributing to a deficient high-fidelity HR pathway and a conducive environment for mutagenesis.IMPORTANCEChlamydia trachomatis induces DNA double-strand breaks in host cells but simultaneously inhibits proper DNA damage response and repair mechanisms. This may render host cells prone to loss of genetic integrity and transformation. Here we show that C. trachomatis prevents activation of the key DNA damage response mediator ATM by preventing the release from PP2A, leading to a complete absence of homologous recombination repair in host cells.
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Affiliation(s)
- Yang Mi
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
- Key Laboratory of H. pylori and Gastrointestinal Microecology of Henan Province, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | | | - Piotr K Zadora
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Thomas F Meyer
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Cindrilla Chumduri
- Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany
- Department of Hepatology and Gastroenterology, Charité University Medicine, Berlin, Germany
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12
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Abstract
Chlamydia spp. are important causes of human disease for which no effective vaccine exists. These obligate intracellular pathogens replicate in a specialized membrane compartment and use a large arsenal of secreted effectors to survive in the hostile intracellular environment of the host. In this Review, we summarize the progress in decoding the interactions between Chlamydia spp. and their hosts that has been made possible by recent technological advances in chlamydial proteomics and genetics. The field is now poised to decipher the molecular mechanisms that underlie the intimate interactions between Chlamydia spp. and their hosts, which will open up many exciting avenues of research for these medically important pathogens.
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Fischer A, Rudel T. Subversion of Cell-Autonomous Host Defense by Chlamydia Infection. Curr Top Microbiol Immunol 2016; 412:81-106. [PMID: 27169422 DOI: 10.1007/82_2016_13] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Obligate intracellular bacteria entirely depend on the metabolites of their host cell for survival and generation of progeny. Due to their lifestyle inside a eukaryotic cell and the lack of any extracellular niche, they have to perfectly adapt to compartmentalized intracellular environment of the host cell and counteract the numerous defense strategies intrinsically present in all eukaryotic cells. This so-called cell-autonomous defense is present in all cell types encountering Chlamydia infection and is in addition closely linked to the cellular innate immune defense of the mammalian host. Cell type and chlamydial species-restricted mechanisms point a long-term evolutionary adaptation that builds the basis of the currently observed host and cell-type tropism among different Chlamydia species. This review will summarize the current knowledge on the strategies pathogenic Chlamydia species have developed to subvert and overcome the multiple mechanisms by which eukaryotic cells defend themselves against intracellular pathogens.
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Affiliation(s)
- Annette Fischer
- Department of Microbiology and Biocenter, University of Würzburg, Am Hubland, 97074, Wuerzburg, Germany
| | - Thomas Rudel
- Department of Microbiology and Biocenter, University of Würzburg, Am Hubland, 97074, Wuerzburg, Germany.
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Dutow P, Wask L, Bothe M, Fehlhaber B, Laudeley R, Rheinheimer C, Yang Z, Zhong G, Glage S, Klos A. An optimized, fast-to-perform mouse lung infection model with the human pathogenChlamydia trachomatisforin vivoscreening of antibiotics, vaccine candidates and modified host–pathogen interactions. Pathog Dis 2015; 74:ftv120. [DOI: 10.1093/femspd/ftv120] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/08/2015] [Indexed: 11/13/2022] Open
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15
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Lü MH, Tang B, Zeng S, Hu CJ, Xie R, Wu YY, Wang SM, He FT, Yang SM. Long noncoding RNA BC032469, a novel competing endogenous RNA, upregulates hTERT expression by sponging miR-1207-5p and promotes proliferation in gastric cancer. Oncogene 2015; 35:3524-34. [PMID: 26549025 DOI: 10.1038/onc.2015.413] [Citation(s) in RCA: 151] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2015] [Revised: 08/18/2015] [Accepted: 09/28/2015] [Indexed: 12/14/2022]
Abstract
Long noncoding RNAs (lncRNAs) are emerging as new players in gene regulation and are associated with the development of cancers. To investigate the important role and mechanism of lncRNAs in the progression of gastric cancer, we screened lncRNAs in gastric cancer tissues and corresponding adjacent tissues, and assessed the effects on gastric cancer. Here, we report that BC032469, a novel lncRNA, expressed highly in gastric cancer tissues, and the upregulation was clinically associated with larger tumor size, poor differentiation and shorter survival of gastric cancer patients. Downregulation of BC032469 resulted in a significant inhibition of proliferation in vitro and in vivo. Mechanistically, BC032469 could directly bind to miR-1207-5p and effectively functioned as a sponge for miR-1207-5p to modulate the derepression of hTERT. Thus, BC032469 may function as a ceRNA to impair miR-1207-5p-dependent hTERT downregulation, suggesting that it may be clinically valuable as a poor prognostic biomarker of gastric cancer.
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Affiliation(s)
- M-H Lü
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, China.,Department of Gastroenterology, The Affiliated Hospital of Luzhou Medical College, Luzhou, China
| | - B Tang
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - S Zeng
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - C-J Hu
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - R Xie
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Y-Y Wu
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - S-M Wang
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - F-T He
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Third Military Medical University, Chongqing, China
| | - S-M Yang
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, China
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Lemercier C. When our genome is targeted by pathogenic bacteria. Cell Mol Life Sci 2015; 72:2665-76. [PMID: 25877988 PMCID: PMC11114081 DOI: 10.1007/s00018-015-1900-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 03/20/2015] [Accepted: 04/02/2015] [Indexed: 01/19/2023]
Abstract
Eukaryotic cells repair thousands of lesions arising in the genome at each cell cycle. The most hazardous damage is likely DNA double-strand breaks (DSB) that cleave the double helix backbone. DSBs occur naturally during T cell receptor and immunoglobulin gene recombination in lymphocytes. DSBs can also arise as a consequence of exogenous stresses (e.g., ionizing irradiation, chemotherapeutic drugs, viruses) or oxidative processes. An increasing number of studies have reported that infection with pathogenic bacteria also alters the host genome, producing DSB and other modifications on DNA. This review focuses on recent data on bacteria-induced DNA damage and the known strategies used by these pathogens to maintain a physiological niche in the host. Even after DNA repair in infected cells, "scars" often remain on chromosomes and might generate genomic instability at the next cell division. Chronic inflammation in tissue, combined with infection and DNA damage, can give rise to genomic instability and eventually cancer. A functional link between the DNA damage response and the innate immune response has been recently established. Pathogenic bacteria also highjack the host cell cycle, often acting on the stability of the master regulator p53, or dampen the DNA damage response to support bacterial replication in an appropriate reservoir. Except in a few cases, the molecular mechanisms responsible for DNA lesions are poorly understood, although ROS release during infection is a serious candidate for generating DNA breaks. Thus, chronic or repetitive infections with genotoxic bacteria represent a common source of DNA lesions that compromise host genome integrity.
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Affiliation(s)
- Claudie Lemercier
- INSERM, UMR_S 1038, BGE (Large Scale Biology), 38054, Grenoble, France,
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Chlamydia infection depends on a functional MDM2-p53 axis. Nat Commun 2014; 5:5201. [PMID: 25392082 PMCID: PMC4243245 DOI: 10.1038/ncomms6201] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Accepted: 09/09/2014] [Indexed: 12/31/2022] Open
Abstract
Chlamydia, a major human bacterial pathogen, assumes effective strategies to protect infected cells against death-inducing stimuli, thereby ensuring completion of its developmental cycle. Paired with its capacity to cause extensive host DNA damage, this poses a potential risk of malignant transformation, consistent with circumstantial epidemiological evidence. Here we reveal a dramatic depletion of p53, a tumor suppressor deregulated in many cancers, during Chlamydia infection. Using biochemical approaches and live imaging of individual cells, we demonstrate that p53 diminution requires phosphorylation of Murine Double Minute 2 (MDM2; a ubiquitin ligase) and subsequent interaction of phospho-MDM2 with p53 before induced proteasomal degradation. Strikingly, inhibition of the p53-MDM2 interaction is sufficient to disrupt intracellular development of Chlamydia and interferes with the pathogen's anti-apoptotic effect on host cells. This highlights the dependency of the pathogen on a functional MDM2-p53 axis and lends support to a potentially pro-carcinogenic effect of chlamydial infection.
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