5 results on '"Ovsepian SV"'
Search Results
2. Exosomes in the Diagnosis and Treatment of Renal Cell Cancer.
- Author
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Boussios S, Devo P, Goodall ICA, Sirlantzis K, Ghose A, Shinde SD, Papadopoulos V, Sanchez E, Rassy E, and Ovsepian SV
- Abstract
Renal cell carcinoma (RCC) is the most prevalent type of kidney cancer originating from renal tubular epithelial cells, with clear cell RCC comprising approximately 80% of cases. The primary treatment modalities for RCC are surgery and targeted therapy, albeit with suboptimal efficacies. Despite progress in RCC research, significant challenges persist, including advanced distant metastasis, delayed diagnosis, and drug resistance. Growing evidence suggests that extracellular vesicles (EVs) play a pivotal role in multiple aspects of RCC, including tumorigenesis, metastasis, immune evasion, and drug response. These membrane-bound vesicles are released into the extracellular environment by nearly all cell types and are capable of transferring various bioactive molecules, including RNA, DNA, proteins, and lipids, aiding intercellular communication. The molecular cargo carried by EVs renders them an attractive resource for biomarker identification, while their multifarious role in the RCC offers opportunities for diagnosis and targeted interventions, including EV-based therapies. As the most versatile type of EVs, exosomes have attracted much attention as nanocarriers of biologicals, with multi-range signaling effects. Despite the growing interest in exosomes, there is currently no widely accepted consensus on their subtypes and properties. The emerging heterogeneity of exosomes presents both methodological challenges and exciting opportunities for diagnostic and clinical interventions. This article reviews the characteristics and functions of exosomes, with a particular reference to the recent advances in their application to the diagnosis and treatment of RCC.
- Published
- 2023
- Full Text
- View/download PDF
3. Enhanced Extracellular Transfer of HLA-DQ Activates CD3 + Lymphocytes towards Compromised Treg Induction in Celiac Disease.
- Author
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Hudec M, Juříčková I, Riegerová K, Ovsepian SV, Černá M, and O'Leary VB
- Subjects
- Alleles, Glutens genetics, HLA-DQ Antigens genetics, Humans, T-Lymphocytes, Regulatory, Celiac Disease
- Abstract
Celiac disease (CeD) manifests with autoimmune intestinal inflammation from gluten and genetic predisposition linked to human leukocyte antigen class-II (HLA-II) gene variants. Antigen-presenting cells facilitate gluten exposition through the interaction of their surface major histocompatibility complex (MHC) with the T cell receptor (TCR) on T lymphocytes. This fundamental mechanism of adaptive immunity has broadened upon recognition of extracellular exosomal MHC, raising awareness of an alternative means for antigen presentation. This study demonstrates that conditioned growth media (CGM) previously exposed to monocyte-derived dendritic cells from CeD significantly downregulates the CD3
+ lineage marker of control T cells. Such increased activation was reflected in their elevated IL-2 secretion. Exosome localization motif identification and quantification within HLA-DQA1 and HLA-DQB1 transcripts highlighted their significant prevalence within HLA-DQB1 alleles associated with CeD susceptibility. Flow cytometry revealed the strong correlation between HLA-DQ and the CD63 exosomal marker in T cells exposed to CGM from MoDCs sourced from CeD patients. This resulted in lower concentrations of CD25+ CD127- T cells, suggestive of their compromised induction to T-regulatory cells associated with CeD homeostasis. This foremost comparative study deciphered the genomic basis and extracellular exosomal effects of HLA transfer on T lymphocytes in the context of CeD, offering greater insight into this auto-immune disease.- Published
- 2022
- Full Text
- View/download PDF
4. Unpacking Pandora From Its Box: Deciphering the Molecular Basis of the SARS-CoV-2 Coronavirus.
- Author
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O'Leary VB, Dolly OJ, Höschl C, Černa M, and Ovsepian SV
- Subjects
- COVID-19 genetics, COVID-19 metabolism, Humans, Open Reading Frames, Pandemics, Phylogeny, RNA, Viral genetics, COVID-19 virology, SARS-CoV-2 genetics, SARS-CoV-2 metabolism, Viral Proteins metabolism
- Abstract
An enigmatic localized pneumonia escalated into a worldwide COVID-19 pandemic from Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). This review aims to consolidate the extensive biological minutiae of SARS-CoV-2 which requires decipherment. Having one of the largest RNA viral genomes, the single strand contains the genes ORF1ab, S, E, M, N and ten open reading frames. Highlighting unique features such as stem-loop formation, slippery frameshifting sequences and ribosomal mimicry, SARS-CoV-2 represents a formidable cellular invader. Hijacking the hosts translational engine, it produces two polyprotein repositories (pp1a and pp1ab), armed with self-cleavage capacity for production of sixteen non-structural proteins. Novel glycosylation sites on the spike trimer reveal unique SARS-CoV-2 features for shielding and cellular internalization. Affording complexity for superior fitness and camouflage, SARS-CoV-2 challenges diagnosis and vaccine vigilance. This review serves the scientific community seeking in-depth molecular details when designing drugs to curb transmission of this biological armament., Competing Interests: All authors declare no conflict of interest.
- Published
- 2020
- Full Text
- View/download PDF
5. Acute and Chronic Sleep Deprivation-Related Changes in N-methyl-D-aspartate Receptor-Nitric Oxide Signalling in the Rat Cerebral Cortex with Reference to Aging and Brain Lateralization.
- Author
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Kristofikova Z, Sirova J, Klaschka J, and Ovsepian SV
- Subjects
- Age Factors, Alzheimer Disease epidemiology, Alzheimer Disease etiology, Animals, Gene Expression Regulation, Male, Membrane Glycoproteins genetics, Membrane Glycoproteins metabolism, Nitric Oxide metabolism, Nitric Oxide Synthase metabolism, Rats, Rats, Wistar, Receptors, N-Methyl-D-Aspartate metabolism, Risk Factors, Sleep Deprivation physiopathology, Aging metabolism, Cerebral Cortex metabolism, Receptors, N-Methyl-D-Aspartate genetics, Signal Transduction, Sleep Deprivation metabolism
- Abstract
Aging and chronic sleep deprivation (SD) are well-recognized risk factors for Alzheimer's disease (AD), with N-methyl-D-aspartate receptor (NMDA) and downstream nitric oxide (NO) signalling implicated in the process. Herein, we investigate the impact of the age- and acute or chronic SD-dependent changes on the expression of NMDA receptor subunits (NR1, NR2A, and NR2B) and on the activities of NO synthase (NOS) isoforms in the cortex of Wistar rats, with reference to cerebral lateralization. In young adult controls, somewhat lateralized seasonal variations in neuronal and endothelial NOS have been observed. In aged rats, overall decreases in NR1, NR2A, and NR2B expression and reduction in neuronal and endothelial NOS activities were found. The age-dependent changes in NR1 and NR2B significantly correlated with neuronal NOS in both hemispheres. Changes evoked by chronic SD (dysfunction of endothelial NOS and the increasing role of NR2A) differed from those evoked by acute SD (increase in inducible NOS in the right side). Collectively, these results demonstrate age-dependent regulation of the level of NMDA receptor subunits and downstream NOS isoforms throughout the rat brain, which could be partly mimicked by SD. As described herein, age and SD alterations in the prevalence of NMDA receptors and NOS could contribute towards cognitive decline in the elderly, as well as in the pathobiology of AD and the neurodegenerative process.
- Published
- 2019
- Full Text
- View/download PDF
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