1
|
Zhdanov DD, Gladilina YA, Shisparenok AN. Apoptotic endonuclease EndoG induces alternative splicing of Caspase-2. BIOMEDITSINSKAIA KHIMIIA 2024; 70:218-230. [PMID: 39239896 DOI: 10.18097/pbmc20247004218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/07/2024]
Abstract
Caspase-2 (Casp-2) is an enzyme that regulates the development of apoptosis upon alternative splicing of its mRNA. The long form of Casp-2 (Casp-2L) promotes apoptosis while the short form (Casp-2S) has decreased enzymatic activity and inhibits the development of apoptotic processes. However, very little is known about the mechanism of Casp-2 alternative splicing. Several endonucleases are known to participate in this process. The aim of this study was to determine the role of EndoG in regulation of Casp-2 alternative splicing. Strong correlation between expression levels of EndoG and Casp-2 splice-variants was found in CD4⁺ and CD8⁺ human T lymphocytes. Such correlation increased after incubation of these cells with etoposide. Increased expression of Casp-2S was determined during EndoG over-expression in CD4⁺ T-cells, after EndoG treatment of cell cytoplasm and nuclei and after nuclei incubation with EndoG digested cell RNA. Casp-2 alternative splicing was induced by a 60-mer RNA oligonucleotide in naked nuclei and in cells after transfection. The identified long non-coding RNA of 1016 nucleotides is the precursor of the 60-mer RNA oligonucleotide. Based on the results the following mechanism has been proposed. Casp-2 pre-mRNA is transcribed from the coding DNA strand while long non-coding RNA is transcribed from the template strand of the Casp-2 gene. EndoG digests long non-coding RNA and produces the 60-mer RNA oligonucleotide complementary to the Casp-2 pre-mRNA exon 9 and intron 9 junction place. Interaction of the 60-mer RNA oligonucleotide and Casp-2 pre-mRNA causes alternative splicing.
Collapse
Affiliation(s)
- D D Zhdanov
- Institute of Biomedical Chemistry, Moscow, Russia
| | | | | |
Collapse
|
2
|
Udroiu I, Marinaccio J, Sgura A. Many Functions of Telomerase Components: Certainties, Doubts, and Inconsistencies. Int J Mol Sci 2022; 23:ijms232315189. [PMID: 36499514 PMCID: PMC9736166 DOI: 10.3390/ijms232315189] [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: 10/25/2022] [Revised: 11/23/2022] [Accepted: 11/29/2022] [Indexed: 12/12/2022] Open
Abstract
A growing number of studies have evidenced non-telomeric functions of "telomerase". Almost all of them, however, investigated the non-canonical effects of the catalytic subunit TERT, and not the telomerase ribonucleoprotein holoenzyme. These functions mainly comprise signal transduction, gene regulation and the increase of anti-oxidative systems. Although less studied, TERC (the RNA component of telomerase) has also been shown to be involved in gene regulation, as well as other functions. All this has led to the publication of many reviews on the subject, which, however, are often disseminating personal interpretations of experimental studies of other researchers as original proofs. Indeed, while some functions such as gene regulation seem ascertained, especially because mechanistic findings have been provided, other ones remain dubious and/or are contradicted by other direct or indirect evidence (e.g., telomerase activity at double-strand break site, RNA polymerase activity of TERT, translation of TERC, mitochondrion-processed TERC). In a critical study of the primary evidence so far obtained, we show those functions for which there is consensus, those showing contradictory results and those needing confirmation. The resulting picture, together with some usually neglected aspects, seems to indicate a link between TERT and TERC functions and cellular stemness and gives possible directions for future research.
Collapse
|
3
|
Xiao J, Joseph S, Xia M, Teng F, Chen X, Huang R, Zhai L, Deng W. Circular RNAs Acting as miRNAs’ Sponges and Their Roles in Stem Cells. J Clin Med 2022; 11:jcm11102909. [PMID: 35629034 PMCID: PMC9145679 DOI: 10.3390/jcm11102909] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 05/10/2022] [Accepted: 05/18/2022] [Indexed: 12/04/2022] Open
Abstract
Circular RNAs (circRNAs), a novel type of endogenous RNAs, have become a subject of intensive research. It has been found that circRNAs are important players in cell differentiation and tissue homeostasis, as well as disease development. Moreover, the expression of circRNAs is usually not correlated with their parental gene expression, indicating that they are not only a steady-state by-product of mRNA splicing but a product of variable splicing under novel regulation. Sequence conservation analysis has also demonstrated that circRNAs have important non-coding functions. CircRNAs exist as a covalently closed loop form in mammalian cells, where they regulate cellular transcription and translation processes. CircRNAs are built from pre-messenger RNAs, and their biogenesis involves back-splicing, which is catalyzed by spliceosomes. The splicing reaction gives rise to three different types of intronic, exotic and exon–intron circular RNAs. Due to higher nuclease stability and longer half lives in cells, circRNAs are more stable than linear RNAs and have enormous clinical advantage for use as diagnostic and therapeutic biomarkers for disease. In recent years, it has been reported that circRNAs in stem cells play a crucial role in stem cell function. In this article, we reviewed the general feature of circRNAs and the distinct roles of circRNAs in stem cell biology, including regulation of stem cell self-renewal and differentiation. CircRNAs have shown unique expression profiles during differentiation of stem cells and could serve as promising biomarkers of these cells. As circRNAs play pivotal roles in stem cell regulation as well as the development and progression of various diseases, we also discuss opportunities and challenges of circRNA-based treatment strategies in future effective therapies for promising clinical applications.
Collapse
Affiliation(s)
- Juan Xiao
- School of Basic Medicine, Hubei University of Arts and Science, Xiangyang 441053, China; (J.X.); (S.J.); (M.X.); (F.T.); (X.C.); (R.H.)
| | - Shija Joseph
- School of Basic Medicine, Hubei University of Arts and Science, Xiangyang 441053, China; (J.X.); (S.J.); (M.X.); (F.T.); (X.C.); (R.H.)
| | - Mengwei Xia
- School of Basic Medicine, Hubei University of Arts and Science, Xiangyang 441053, China; (J.X.); (S.J.); (M.X.); (F.T.); (X.C.); (R.H.)
| | - Feng Teng
- School of Basic Medicine, Hubei University of Arts and Science, Xiangyang 441053, China; (J.X.); (S.J.); (M.X.); (F.T.); (X.C.); (R.H.)
| | - Xuejiao Chen
- School of Basic Medicine, Hubei University of Arts and Science, Xiangyang 441053, China; (J.X.); (S.J.); (M.X.); (F.T.); (X.C.); (R.H.)
| | - Rufeng Huang
- School of Basic Medicine, Hubei University of Arts and Science, Xiangyang 441053, China; (J.X.); (S.J.); (M.X.); (F.T.); (X.C.); (R.H.)
| | - Lihong Zhai
- School of Basic Medicine, Hubei University of Arts and Science, Xiangyang 441053, China; (J.X.); (S.J.); (M.X.); (F.T.); (X.C.); (R.H.)
- Correspondence: (L.Z.); (W.D.)
| | - Wenbin Deng
- School of Pharmaceutical Sciences (Shenzhen), Sun Yat-sen University, Shenzhen 510060, China
- Jiangxi Deshang Pharmaceutical Co., Ltd., Zhangshu 336000, China
- Correspondence: (L.Z.); (W.D.)
| |
Collapse
|
4
|
Blinova VG, Gladilina YA, Eliseeva DD, Lobaeva TA, Zhdanov DD. [Increased suppressor activity of transformed ex vivo regulatory T-cells in comparison with unstimulated cells of the same donor]. BIOMEDITSINSKAIA KHIMIIA 2022; 68:55-67. [PMID: 35221297 DOI: 10.18097/pbmc20226801055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Regulatory T-cells CD4⁺CD25⁺FoxP3⁺CD127low (Tregs) play a key role in the maintenance of tolerance to auto antigens, inhibit function of effector T and B lymphocytes, and provide a balance between effector and regulatory arms of immunity. Patients with autoimmune diseases have decreased Treg numbers and impaired suppressive activity. Transformed ex vivo autologous Tregs could restore destroyed balance of the immune system. We developed a method for Treg precursor cell cultivation. Following the method, we were able to grown up 300-400 million of Tregs cells from 50 ml of peripheral blood during a week. Transformed ex vivo Tregs are 90-95% CD4⁺CD25⁺FoxP3⁺CD127low and have increased expression of transcription genes FoxP3 and Helios. Transformed ex vivo Tregs have increased demethylation of FoxP3 promoter and activated genes of proliferation markers Cycline B1, Ki67 and LGALS 1. Transformed ex vivo Tregs have increased suppressive activity and up to 80-90% these cells secrete cytokines TNFα и IFNγ. Our data suggest transformed ex vivo autologous Tregs have genetic, immunophenotypic and functional characteristics for regulatory T-cells and further can be used for adoptive immunotherapy autoimmune diseases and inhibition of transplantation immunity.
Collapse
Affiliation(s)
- V G Blinova
- Institute of Biomedical Chemistry, Moscow, Russia
| | | | | | - T A Lobaeva
- Department of Biochemistry, Peoples Friendship University of Russia (RUDN University), Moscow, Russia
| | - D D Zhdanov
- Institute of Biomedical Chemistry, Moscow, Russia; Department of Biochemistry, Peoples Friendship University of Russia (RUDN University), Moscow, Russia
| |
Collapse
|
5
|
Plyasova AA, Berrino E, Khan II, Veselovsky AV, Pokrovsky VS, Angeli A, Ferraroni M, Supuran CT, Pokrovskaya MV, Alexandrova SS, Gladilina YA, Sokolov NN, Hilal A, Carta F, Zhdanov DD. Mechanisms of the Antiproliferative and Antitumor Activity of Novel Telomerase-Carbonic Anhydrase Dual-Hybrid Inhibitors. J Med Chem 2021; 64:11432-11444. [PMID: 34283610 DOI: 10.1021/acs.jmedchem.1c00756] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Human (h) telomerase (TL; EC 2.7.7.49) plays a key role in sustaining cancer cells by means of elongating telomeric repeats at the 3' ends of chromosomes. Since TL-inhibitor (TI) stand-alone cancer therapy has been proven to be remarkably challenging, a polypharmacological approach represents a valid alternative. Here we consider a series of compounds able to inhibit both hTL and the tumor-associated carbonic anhydrases (CAs; EC 4.2.1.1) IX and XII. Compounds 7 and 9 suppressed hTL activity in both cell lysates and human colon cancer cell lines, and prolonged incubation with either 7 or 9 resulted in telomere shortening, cell cycle arrest, replicative senescence, and apoptosis. Enzyme kinetics showed that 7 and 9 are mixed-type inhibitors of the binding of DNA primers and deoxynucleoside triphosphate (dNTP) to the TL catalytic subunit hTERT, which is in agreement with docking experiments. Compound 9 showed antitumor activity in Colo-205 mouse xenografts and suppressed telomerase activity by telomere reduction.
Collapse
Affiliation(s)
- Anna A Plyasova
- Institute of Biomedical Chemistry, Pogodinskaya Street 10/8, Moscow 119121, Russia
| | - Emanuela Berrino
- Dipartimento di Neurofarba, Sezione di Scienze Farmaceutiche e Nutraceutiche, Università degli Studi di Firenze, Via Ugo Schiff 6, 50019 Florence, Italy
| | - Irina I Khan
- Peoples' Friendship University of Russia (RUDN University), Miklukho-Maklaya Street 6, Moscow 117198, Russia.,N.N. Blokhin Cancer Research Center, Kashirskoe Shosse 24, Moscow 115478, Russia
| | | | - Vadim S Pokrovsky
- Peoples' Friendship University of Russia (RUDN University), Miklukho-Maklaya Street 6, Moscow 117198, Russia.,N.N. Blokhin Cancer Research Center, Kashirskoe Shosse 24, Moscow 115478, Russia
| | - Andrea Angeli
- Dipartimento di Neurofarba, Sezione di Scienze Farmaceutiche e Nutraceutiche, Università degli Studi di Firenze, Via Ugo Schiff 6, 50019 Florence, Italy
| | - Marta Ferraroni
- Dipartimento di Chimica "Ugo Schiff", Università degli Studi di Firenze, Via della Lastruccia 3-13, 50019 Florence, Italy
| | - Claudiu T Supuran
- Dipartimento di Neurofarba, Sezione di Scienze Farmaceutiche e Nutraceutiche, Università degli Studi di Firenze, Via Ugo Schiff 6, 50019 Florence, Italy
| | - Marina V Pokrovskaya
- Institute of Biomedical Chemistry, Pogodinskaya Street 10/8, Moscow 119121, Russia
| | | | - Yulia A Gladilina
- Institute of Biomedical Chemistry, Pogodinskaya Street 10/8, Moscow 119121, Russia
| | - Nikolay N Sokolov
- Institute of Biomedical Chemistry, Pogodinskaya Street 10/8, Moscow 119121, Russia
| | - Abdullah Hilal
- Institute of Biomedical Chemistry, Pogodinskaya Street 10/8, Moscow 119121, Russia
| | - Fabrizio Carta
- Dipartimento di Neurofarba, Sezione di Scienze Farmaceutiche e Nutraceutiche, Università degli Studi di Firenze, Via Ugo Schiff 6, 50019 Florence, Italy
| | - Dmitry D Zhdanov
- Institute of Biomedical Chemistry, Pogodinskaya Street 10/8, Moscow 119121, Russia
| |
Collapse
|
6
|
Plyasova AA, Zhdanov DD. Alternative Splicing of Human Telomerase Reverse Transcriptase (hTERT) and Its Implications in Physiological and Pathological Processes. Biomedicines 2021; 9:526. [PMID: 34065134 PMCID: PMC8150890 DOI: 10.3390/biomedicines9050526] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 05/03/2021] [Accepted: 05/05/2021] [Indexed: 12/24/2022] Open
Abstract
Alternative splicing (AS) of human telomerase catalytic subunit (hTERT, human telomerase reverse transcriptase) pre-mRNA strongly regulates telomerase activity. Several proteins can regulate AS in a cell type-specific manner and determine the functions of cells. In addition to being involved in telomerase activity regulation, AS provides cells with different splice variants that may have alternative biological activities. The modulation of telomerase activity through the induction of hTERT AS is involved in the development of different cancer types and embryos, and the differentiation of stem cells. Regulatory T cells may suppress the proliferation of target human and murine T and B lymphocytes and NK cells in a contact-independent manner involving activation of TERT AS. This review focuses on the mechanism of regulation of hTERT pre-mRNA AS and the involvement of splice variants in physiological and pathological processes.
Collapse
Affiliation(s)
| | - Dmitry D. Zhdanov
- Institute of Biomedical Chemistry, Pogodinskaya st 10/8, 119121 Moscow, Russia;
| |
Collapse
|
7
|
Cai L, Sun Y, Wang K, Guan W, Yue J, Li J, Wang R, Wang L. The Better Survival of MSI Subtype Is Associated With the Oxidative Stress Related Pathways in Gastric Cancer. Front Oncol 2020; 10:1269. [PMID: 32850385 PMCID: PMC7399340 DOI: 10.3389/fonc.2020.01269] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 06/18/2020] [Indexed: 12/29/2022] Open
Abstract
Background: Gastric cancer (GC) is the third leading fatal cancer in the world and its incidence ranked second among all malignant tumors in China. The molecular classification of GC, proposed by the The Cancer Genome Atlas (TCGA), was added to the updated edition (2019) of WHO classification for digestive system tumor. Although MSI and EBV subtypes appeared as ever-increasingly significant roles in immune checkpoint inhibitor therapy, the underlying mechanisms are still unclear. Methods: We systematically summarized the relationship between EBV, d-MMR/MSI-H subtypes and clinicopathological parameters in 271 GC cases. Furthermore, GSE62254/ACRG and TCGA-STAD datasets, originated from Gene Expression Omnibus (GEO) and TCGA respectively, were analyzed to figure out the prognosis related molecular characteristics by bioinformatics methods. Results: Patients with MSI subtype had better prognosis than the MSS subtype (P = 0.013) and considered as an independent biomarker by the univariate analysis (P = 0.017) and multivariate analysis (P = 0.050). While there was no significant difference between EBV positive and negative tissues (P = 0.533). The positive prognostic value conferred by MSI in different cohorts was revalidated via the clinical analysis of GSE62254/ACRG and TCGA-STAD datasets regardless of race. Then key gene module that tightly associated with better status and longer OS time for MSI cases was obtained from weighted gene co-expression network analysis(WGCNA). NUBP2 and ENDOG were screened from the gene cluster and oxidative phosphorylation, reactive oxygen species(ROS) and glutathione metabolism were analyzed to be the differential pathways in their highly expressed groups. Conclusions: Our results manifested the significant prognostic value of MSI in Chinese GC cohort and comparisons with other populations. More opportunities to induce apoptosis of cancer cells, led by the unbalance between antioxidant system and ROS accumulation, lay foundations for unveiling the better prognosis in MSI phenotype through the bioinformatics analysis.
Collapse
Affiliation(s)
- Lei Cai
- Department of Pathology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yeqi Sun
- Department of Pathology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Kezhou Wang
- Department of Pathology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Wenbin Guan
- Department of Pathology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Juanqing Yue
- Department of Pathology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Junlei Li
- Department of Pathology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Ruifen Wang
- Department of Pathology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Lifeng Wang
- Department of Pathology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| |
Collapse
|
8
|
Zhdanov DD, Plyasova AA, Gladilina YA, Pokrovsky VS, Grishin DV, Grachev VA, Orlova VS, Pokrovskaya MV, Alexandrova SS, Lobaeva TA, Sokolov NN. Inhibition of telomerase activity by splice-switching oligonucleotides targeting the mRNA of the telomerase catalytic subunit affects proliferation of human CD4 + T lymphocytes. Biochem Biophys Res Commun 2019; 509:790-796. [PMID: 30612734 DOI: 10.1016/j.bbrc.2018.12.186] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Accepted: 12/31/2018] [Indexed: 02/08/2023]
Abstract
Telomerase activity is regulated at the mRNA level by alternative splicing (AS) of its catalytic subunit hTERT. The aim of this study was to define the ability of splice-switching oligonucleotides (SSOs) that pair with hTERT pre-mRNA to induce AS and inhibit telomerase activity in human CD4+ T lymphocytes. SSOs that blocked the binding of a single splicing regulatory protein, SRp20 or SRp40, to its site within intron 8 of hTERT pre-mRNA demonstrated rather moderate capacities to induce AS and inhibit telomerase. However, a SSO that blocked the interaction of both SRp20 and SRp40 proteins with pre-mRNA was the most active. Cultivation of lymphocytes with spliced hTERT and inhibited telomerase resulted in the reduction of proliferative activity without significant induction of cell death. These results should facilitate further investigation of telomerase activity regulation, and antitelomerase SSOs could become promising agents for antiproliferative cell therapy.
Collapse
Affiliation(s)
- Dmitry D Zhdanov
- Institute of Biomedical Chemistry, 10/8 Pogodinskaya st, 119121, Moscow, Russia; Рeoples' Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya Street, 117198, Moscow, Russia.
| | - Anna A Plyasova
- Institute of Biomedical Chemistry, 10/8 Pogodinskaya st, 119121, Moscow, Russia
| | - Yulia A Gladilina
- Institute of Biomedical Chemistry, 10/8 Pogodinskaya st, 119121, Moscow, Russia
| | - Vadim S Pokrovsky
- Institute of Biomedical Chemistry, 10/8 Pogodinskaya st, 119121, Moscow, Russia; Рeoples' Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya Street, 117198, Moscow, Russia; N.N. Blokhin Cancer Research Center, 24 Kashirskoe Shosse, 115478, Moscow, Russia
| | - Dmitry V Grishin
- Institute of Biomedical Chemistry, 10/8 Pogodinskaya st, 119121, Moscow, Russia
| | - Vladimir A Grachev
- Рeoples' Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya Street, 117198, Moscow, Russia
| | - Valentina S Orlova
- Рeoples' Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya Street, 117198, Moscow, Russia
| | | | | | - Tatiana A Lobaeva
- Рeoples' Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya Street, 117198, Moscow, Russia
| | - Nikolay N Sokolov
- Institute of Biomedical Chemistry, 10/8 Pogodinskaya st, 119121, Moscow, Russia
| |
Collapse
|
9
|
Zhdanov DD, Gladilina YA, Pokrovsky VS, Grishin DV, Grachev VA, Orlova VS, Pokrovskaya MV, Alexandrova SS, Plyasova AA, Sokolov NN. Endonuclease G modulates the alternative splicing of deoxyribonuclease 1 mRNA in human CD4 + T lymphocytes and prevents the progression of apoptosis. Biochimie 2018; 157:158-176. [PMID: 30521874 DOI: 10.1016/j.biochi.2018.11.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 11/30/2018] [Indexed: 02/08/2023]
Abstract
Apoptotic endonucleases act cooperatively to fragment DNA and ensure the irreversibility of apoptosis. However, very little is known regarding the potential regulatory links between endonucleases. Deoxyribonuclease 1 (DNase I) inactivation is caused by alternative splicing (AS) of DNase I pre-mRNA skipping exon 4, which occurs in response to EndoG overexpression in cells. The current study aimed to determine the role of EndoG in the regulation of DNase I mRNA AS and the modulation of its enzymatic activity. A strong correlation was identified between the EndoG expression levels and DNase I splice variants in human lymphocytes. EndoG overexpression in CD4+ T cells down-regulated the mRNA levels of the active full-length DNase I variant and up-regulated the levels of the non-active spliced variant, which acts in a dominant-negative fashion. DNase I AS was induced by the translocation of EndoG from mitochondria into nuclei during the development of apoptosis. The DNase I spliced variant was induced by recombinant EndoG or by incubation with EndoG-digested cellular RNA in an in vitro system with isolated cell nuclei. Using antisense DNA oligonucleotides, we identified a 72-base segment that spans the adjacent segments of exon 4 and intron 4 and appears to be responsible for the AS. DNase I-positive CD4+ T cells overexpressing EndoG demonstrated decreased progression towards bleomycin-induced apoptosis. Therefore, EndoG is an endonuclease with the unique ability to inactivate another endonuclease, DNase I, and to modulate the development of apoptosis.
Collapse
Affiliation(s)
- Dmitry D Zhdanov
- Institute of Biomedical Chemistry, Pogodinskaya St 10/8, 119121, Moscow, Russia; Peoples Friendship University of Russia (RUDN University), Miklukho-Maklaya 6, 117198, Moscow, Russia.
| | - Yulia A Gladilina
- Institute of Biomedical Chemistry, Pogodinskaya St 10/8, 119121, Moscow, Russia
| | - Vadim S Pokrovsky
- Institute of Biomedical Chemistry, Pogodinskaya St 10/8, 119121, Moscow, Russia; Peoples Friendship University of Russia (RUDN University), Miklukho-Maklaya 6, 117198, Moscow, Russia; N.N. Blokhin Cancer Research Center, Kashirskoe Shosse 24, 115478, Moscow, Russia
| | - Dmitry V Grishin
- Institute of Biomedical Chemistry, Pogodinskaya St 10/8, 119121, Moscow, Russia
| | - Vladimir A Grachev
- Peoples Friendship University of Russia (RUDN University), Miklukho-Maklaya 6, 117198, Moscow, Russia
| | - Valentina S Orlova
- Peoples Friendship University of Russia (RUDN University), Miklukho-Maklaya 6, 117198, Moscow, Russia
| | | | | | - Anna A Plyasova
- Institute of Biomedical Chemistry, Pogodinskaya St 10/8, 119121, Moscow, Russia
| | - Nikolay N Sokolov
- Institute of Biomedical Chemistry, Pogodinskaya St 10/8, 119121, Moscow, Russia
| |
Collapse
|
10
|
Contact-independent suppressive activity of regulatory T cells is associated with telomerase inhibition, telomere shortening and target lymphocyte apoptosis. Mol Immunol 2018; 101:229-244. [PMID: 30025223 DOI: 10.1016/j.molimm.2018.07.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 07/02/2018] [Accepted: 07/11/2018] [Indexed: 02/08/2023]
Abstract
Regulatory T cells (Tregs) play a fundamental role in the maintenance of immunological tolerance by suppressing effector target T, B and NK lymphocytes. Contact-dependent suppression mechanisms have been well-studied, though contact-independent Treg activity is not fully understood. In the present study, we showed that human native Tregs, as well as induced ex vivo Tregs, can cause in vitro telomere-dependent senescence in target T, B and NK cells in a contact-independent manner. The co-cultivation of target cells with Tregs separated through porous membranes induced alternative splicing of the telomerase catalytic subunit hTERT (human Telomerase Reverse Transcriptase), which suppressed telomerase activity. Induction of the hTERT splicing variant was associated with increased expression of the apoptotic endonuclease EndoG, a splicing regulator. Inhibited telomerase in target cells co-cultivated with Tregs for a long period of time led to a decrease in their telomere lengths, cell cycle arrest, conversion of the target cells to replicative senescence and apoptotic death. Induced Tregs showed the ability to up-regulate EndoG expression, TERT alternative splicing and telomerase inhibition in mouse T, B and NK cells after in vivo administration. The results of the present study describe a novel mechanism of contact-independent Treg cell suppression that induces telomerase inhibition through the EndoG-provoked alternative splicing of hTERT and converts cells to senescence and apoptosis phenotypes.
Collapse
|
11
|
Zhdanov DD, Gladilina YA, Pokrovsky VS, Grishin DV, Grachev VA, Orlova VS, Pokrovskaya MV, Alexandrova SS, Sokolov NN. Murine regulatory T cells induce death of effector T, B, and NK lymphocytes through a contact-independent mechanism involving telomerase suppression and telomere-associated senescence. Cell Immunol 2018; 331:146-160. [PMID: 29935763 DOI: 10.1016/j.cellimm.2018.06.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 05/22/2018] [Accepted: 06/18/2018] [Indexed: 12/30/2022]
Abstract
Regulatory T cells (Tregs) suppress the activity of effector T, B and NK lymphocytes and sustain immunological tolerance, but the proliferative activity of suppressed cells remains unexplored. In the present study, we report that mouse Tregs can induce replicative senescence and the death of responder mouse CD4+CD25- T cells, CD8+ T cells, B cells and NK cells in vitro and in vivo. Contact-independent in vitro co-cultivation with Tregs up-regulated endonuclease G (EndoG) expression and its translocation to the nucleus in responder cells. EndoG localization in the nucleus induced alternative mRNA splicing of the telomerase catalytic subunit Tert and telomerase inhibition. The lack of telomerase activity in proliferating cells led to telomere loss followed by the development of senescence and cell death. Injection of Tregs into mice resulted in EndoG-associated alternative splicing of Tert, telomerase inhibition, telomere loss, senescence development and increased cell death in vivo. The present study describes a novel contact-independent mechanism by which Tregs specify effector cell fate and provides new insights into cellular crosstalk related to immune suppression.
Collapse
Affiliation(s)
- Dmitry D Zhdanov
- Institute of Biomedical Chemistry, Pogodinskaya st 10/8, 119121 Moscow, Russia; Peoples Friendship University of Russia (RUDN University), Miklukho-Maklaya 6, 117198 Moscow, Russia.
| | - Yulia A Gladilina
- Institute of Biomedical Chemistry, Pogodinskaya st 10/8, 119121 Moscow, Russia
| | - Vadim S Pokrovsky
- Institute of Biomedical Chemistry, Pogodinskaya st 10/8, 119121 Moscow, Russia; Peoples Friendship University of Russia (RUDN University), Miklukho-Maklaya 6, 117198 Moscow, Russia; N.N. Blokhin Cancer Research Center, Kashirskoe Shosse 24, 115478 Moscow, Russia
| | - Dmitry V Grishin
- Institute of Biomedical Chemistry, Pogodinskaya st 10/8, 119121 Moscow, Russia
| | - Vladimir A Grachev
- Peoples Friendship University of Russia (RUDN University), Miklukho-Maklaya 6, 117198 Moscow, Russia
| | - Valentina S Orlova
- Peoples Friendship University of Russia (RUDN University), Miklukho-Maklaya 6, 117198 Moscow, Russia
| | | | | | - Nikolay N Sokolov
- Institute of Biomedical Chemistry, Pogodinskaya st 10/8, 119121 Moscow, Russia
| |
Collapse
|
12
|
Serakinci N, Mega Tiber P, Orun O. Chromatin modifications of hTERT gene in hTERT-immortalized human mesenchymal stem cells upon exposure to radiation. Eur J Med Genet 2018; 61:288-293. [DOI: 10.1016/j.ejmg.2017.12.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 12/14/2017] [Accepted: 12/23/2017] [Indexed: 01/24/2023]
|
13
|
Zhdanov DD, Vasina DA, Grachev VA, Orlova EV, Orlova VS, Pokrovskaya MV, Alexandrova SS, Sokolov NN. Alternative splicing of telomerase catalytic subunit hTERT generated by apoptotic endonuclease EndoG induces human CD4 + T cell death. Eur J Cell Biol 2017; 96:653-664. [PMID: 28886883 DOI: 10.1016/j.ejcb.2017.08.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 08/24/2017] [Accepted: 08/30/2017] [Indexed: 02/08/2023] Open
Abstract
Telomerase activity is regulated by alternative splicing of its catalytic subunit human Telomerase Reverse Transcriptase (hTERT) mRNA. Induction of a non-active spliced hTERT leads to inhibition of telomerase activity. However, very little is known about the mechanism of hTERT mRNA alternative splicing. The aim of this study was to determine the role of the apoptotic endonuclease EndoG in alternative splicing of hTERT and telomerase activity. A strong correlation was identified between EndoG expression levels and hTERT splice variants in human CD4+ and CD8+ T lymphocytes. Overexpression of EndoG in CD4+ T cells down-regulated the expression of the active full-length hTERT variant and up-regulated expression of the non-active spliced variant. A reduction in full-length hTERT transcripts down-regulated telomerase activity. Long-term in vitro cultivation of EndoG-overexpressing CD4+ T cells led to dramatically shortened telomeres, conversion of cells into a replicative senescence state, and activation of the BCL2/BAX-associated apoptotic pathway finally leading to cell death. These data indicated the participation of EndoG in alternative mRNA splicing of the telomerase catalytic subunit hTERT, regulation of telomerase activity and determination of cell fate.
Collapse
Affiliation(s)
- Dmitry D Zhdanov
- Laboratory of Medical Biotechnology, Institute of Biomedical Chemistry, Moscow, Russia; Peoples Friendship University of Russia, Moscow, Russia.
| | | | | | - Elena V Orlova
- Institute of Theoretical and Experimental Biophysics, Puschino, Moscow region, Russia
| | | | - Marina V Pokrovskaya
- Laboratory of Medical Biotechnology, Institute of Biomedical Chemistry, Moscow, Russia
| | | | - Nikolai N Sokolov
- Laboratory of Medical Biotechnology, Institute of Biomedical Chemistry, Moscow, Russia
| |
Collapse
|