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Browsing by Author "Svirskis, Simons"

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Biomarkers in the diagnostic algorithm of myalgic encephalomyelitis/chronic fatigue syndrome
(2022-10-10) Grāvelsiņa, Sabīne; Vilmane, Anda; Svirskis, Simons; Rasa-Dzelzkaleja, Santa; Nora-Krūkle, Zaiga; Vecvagare, Katrine; Krumina, Angelika; Leineman, Iana; Shoenfeld, Yehuda; Murovska, Modra; Institute of Microbiology and Virology; Department of Infectology
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex disease that is mainly diagnosed based on its clinical symptoms. Biomarkers that could facilitate the diagnosis of ME/CFS are not yet available; therefore, reliable and clinically useful disease indicators are of high importance. The aim of this work was to analyze the association between ME/CFS clinical course severity, presence of HHV-6A/B infection markers, and plasma levels of autoantibodies against adrenergic and muscarinic acetylcholine receptors. A total of 134 patients with ME/CFS and 33 healthy controls were analyzed for the presence of HHV-6A/B using PCRs, and antibodies against beta2-adrenergic receptors (β2AdR) and muscarinic acetylcholine receptors (M3 AChR and M4 AChR) using ELISAs. HHV-6A/B U3 genomic sequence in whole-blood DNA was detected in 19/31 patients with severe ME/CFS, in 18/73 moderate ME/CFS cases, and in 7/30 mild ME/CFS cases. Severity-related differences were found among those with a virus load of more than 1,000 copies/106 PBMCs. Although no disease severity-related differences in anti-β2AdR levels were observed in ME/CFS patients, the median concentration of these antibodies in plasma samples of ME/CFS patients was 1.4 ng/ml, while in healthy controls, it was 0.81 ng/ml, with a statistically significant increased level in those with ME/CFS (p = 0.0103). A significant difference of antibodies against M4 AChR median concentration was found between ME/CFS patients (8.15 ng/ml) and healthy controls (6.45 ng/ml) (p = 0.0250). The levels of anti-M4 plotted against disease severity did not show any difference; however, increased viral load correlates with the increase in anti-M4 level. ME/CFS patients with high HHV-6 load have a more severe course of the disease, thus confirming that the severity of the disease depends on the viral load—the course of the disease is more severe with a higher viral load. An increase in anti-M4 AchR and anti-β2AdR levels is detected in all ME/CFS patient groups in comparison to the control group not depending on ME/CFS clinical course severity. However, the increase in HHV-6 load correlates with the increase in anti-M4 level, and the increase in anti-M4 level, in turn, is associated with the increase in anti-β2AdR level. Elevated levels of antibodies against β2AdR and M4 receptors in ME/CFS patients support their usage as clinical biomarkers in the diagnostic algorithm of ME/CFS.
Chemokine Receptors CCR1 and CCR2 on Peripheral Blood Mononuclear Cells of Newly Diagnosed Patients with the CD38-Positive Chronic Lymphocytic Leukemia
(2020-07-21) Kholodnyuk, Irina; Rivkina, Alla; Hippe, Laura; Svirskis, Simons; Kozireva, Svetlana; Ventina, Ildze; Spaka, Irina; Soloveichika, Marina; Pavlova, Jelena; Murovska, Modra; Lejniece, Sandra
Chemokines and their receptors direct migration and infiltration of immune cells. CCR1 and CCR2 maintain sequence similarity and respond to a number of the same chemokines secreted in lymphoid organs. Expression of CD38 on leukemic cells has been associated with poor clinical outcomes in patients with chronic lymphocytic leukemia (CLL) and is considered as the negative predictor of progression. In our study of newly diagnosed CLL patients, which included 39 CD38-positive and 22 CD38-negative patients, CCR1 and/or CCR2 were always detected, using flow cytometry, on the peripheral blood (PB) CD19+CD5+ lymphocytes in patients with >30% of the CD38+ CD19+CD5+ lymphocytes (n = 16). Spearman’s rank correlation analysis determined correlations between the frequency of the CCR1- and CCR2-expressing PB CD19+CD5+ lymphocytes and the frequency of the CD38-positive CD19+CD5+ lymphocytes (rs = 0.50 and rs = 0.38, respectively). No significant correlations were observed between ZAP70 mRNA expression levels in PB mononuclear cells and the frequency of the circulating CCR1+ or CCR2+ CD19+CD5+ lymphocytes. Further association studies are needed to verify prognostic relevance of the CCR1/CCR2 expression on leukemic cells in CLL patients at diagnosis. We suggest that CCR1/CCR2 signaling pathways could represent attractive targets for development of CLL anti-progression therapeutics.
Comparative study of taurine and tauropyrone : GABA receptor binding, mitochondrial processes and behaviour
(2011-02) Dzirkale, Zane; Pupure, Jolanta; Rumaks, Juris; Svirskis, Simons; Vanina, Marija; Mezhapuke, Rudolfs; Sile, Velga; Fernandes, Maria Augusta; Duburs, Gunars; Klusa, Vija
Objectives Taurine, a sulfur-containing amino acid, has high hydrophilicity and is poorly absorbed. Tauropyrone, a taurine-containing 1,4-dihydropyridine derivative, is suggested to have greater activity than taurine owing to improved physicochemical properties that facilitate delivery of the compound to target cells. The aim of this study was to determine whether the 1,4-dihydropyridine moiety in tauropyrone improves the pharmacological efficacy of taurine in vitro and in vivo. Methods The effects of taurine and tauropyrone, as well as of the 1,4-dihydropyridine moiety were compared in in-vitro experiments to determine the binding to GABA receptors and influence on mitochondrial processes (isolated rat liver mitochondria), and in in-vivo tests to assess the influence on behavioural effects caused by the GABA-A receptor ligands, bicuculline, diazepam and ethanol. Key findings Unlike taurine, tauropyrone did not display binding activity for the GABA-A receptor, and only taurine (but not tauropyrone) at low doses (0.1, 1.0 and 10 mg/kg) antagonised the bicuculline-induced convulsion effect. Taurine and tauropyrone had no effect on diazepam myorelaxing action, and they both exerted a comparable 'anti-ethanol' effect (shortening of the ethanol-sleeping time). Taurine and tauropyrone did not influence processes of mitochondrial bioenergetics. Conclusions The action of tauropyrone at the level of the GABA-A receptor differs qualitatively from that of taurine, probably because of its 1,4-dihydropyridine moiety, which may hinder access to the GABA-A receptor GABA site. Tauropyrone does not show improved pharmacological efficacy in in-vitro and in-vivo studies in comparison with taurine.
Curcumin effect on copper transport in HepG2 cells
(2018-05) Berzina, Anita; Martinsone, Inese; Svirskis, Simons; Murovska, Modra; Kalis, Martins; Institute of Occupational Safety and Environmental Health; Institute of Microbiology and Virology
Background and Objective: In Wilson’s disease, copper metabolism is impaired due to defective copper transporting protein ATP7B, resulting in copper accumulation in liver and brain and causing damage to liver and brain tissues. Published data suggest that one of the possible treatments for Wilson’s disease is curcumin—a compound found in the root of Curcuma longa. In this study, we tested whether curcumin affects copper transport and excretion in HepG2 hepatocytes carrying wildtype ATP7B. Materials and Methods: We examined the impact of 5 µM and 25 µM curcumin on the transport of copper in HepG2 cells incubated with 20 µM and 100 µM CuCl2, as well as copper excretion from cells. First, immunofluorescent staining and co-localization analysis were carried out in HepG2 cells using confocal laser scanning microscope and Nikon NIS Elements software. Second, a concentration of copper extracted into cell culture medium was determined using atomic absorption spectrometry. Results: The analysis of the co-localization between Golgi complex and ATP7B revealed that both 5 µM and 25 µM doses of curcumin improve the ability of liver cells to transport copper to plasma membrane at 20 µM CuCl2, but not at 100 µM CuCl2 concentration. However, atomic absorption spectrometry showed that curcumin rather promotes copper absorption into liver cell line HepG2 than excretion of it. Conclusions: Curcumin accelerates the transport of copper within liver cells, but does not promote copper excretion from HepG2 cells.
DNA immunization site determines the level of gene expression and the magnitude, but not the type of the induced immune response
(2018-06-04) Petkov, Stefan; Starodubova, Elizaveta; Latanova, Anastasia; Kilpelainen, Athina; Latyshev, Oleg; Svirskis, Simons; Wahren, Britta; Chiodi, Francesca; Gordeychuk, Ilya; Isaguliants, Maria; Rīga Stradiņš University
Effect of Human Herpesviruses 6 and 7 Infection on the Clinical Course of Rheumatoid Arthritis
(2016-08-01) Kadiša, Anda; Nora-Krūkle, Zaiga; Kozireva, Svetlana; Svirskis, Simons; Studers, Peteris; Groma, Valerija; Lejnieks, Aivars; Murovska, Modra; Department of Internal Diseases; Institute of Microbiology and Virology; Joint Laboratory of Traumatology and Orthopaedics; Institute of Anatomy and Anthropology
Rheumatoid arthritis (RA) is a chronic systemic autoimmune inflammatory disease affecting joints and causing symmetrical chronic progressive aseptic synovitis and erosive-destructive changes. Viruses and viral infections are considered to be the main risk factors for autoimmune disease development (especially for individuals with genetic predisposition). The goal of this study was to evaluate the frequency of HHV-6 and HHV-7 persistent infection and its activity phase in RA and osteoarthritis (OA) patients, and healthy persons. We examined also the influence of HHV-6 and-7 infections on RA activity, aggressiveness, radiographical stage, and frequency of complications as well as the presence of HHV-6 infection markers in synovial fluid and synovial tissues of RA joints of affected patients. Despite the lack of significant correlation between frequency of persistent single HHV-6, single HHV-7, and concurrent HHV-6 and HHV-7 infection and RA clinical course, we found that both active and latent HHV-6 and/or HHV-7 infection increased RA activity and progression in several clinical and laboratory parameters. Regarding the severity of the course of RA, we observed also a high prevalence of RA complications in the patient group with active single HHV-6 infection and also a more severe radiographical stage in RA patients with active concurrent HHV-6 and HHV-7 infection. Moreover, viral infection markers were found in synovial fluid and synovial tissues of affected joints of RA patients. This suggests that HHV-6 and/or HHV-7 infection has effect on the disease clinical course, but virus reactivation may be a consequence of immunosuppressive treatment.
Evidence of human parvovirus B19 infection in the post-mortem brain tissue of the elderly
(2018-11) Skuja, Sandra; Vilmane, Anda; Svirskis, Simons; Groma, Valerija; Murovska, Modra; Institute of Anatomy and Anthropology; Institute of Microbiology and Virology
After primary exposure, the human parvovirus B19 (B19V) genome may remain in the central nervous system (CNS), establishing a lifelong latency. The structural characteristics and functions of the infected cells are essential for the virus to complete its life cycle. Although B19V has been detected in the brain tissue by sequencing PCR products, little is known about its in vivo cell tropism and pathogenic potential in the CNS. To detect B19V and investigate the distribution of its target cells in the CNS, we studied brain autopsies of elderly subjects using molecular virology, and optical and electron microscopy methods. Our study detected B19V in brain tissue samples from both encephalopathy and control groups, suggesting virus persistence within the CNS throughout the host’s lifetime. It appears that within the CNS, the main target of B19V is oligodendrocytes. The greatest number of B19V-positive oligodendrocytes was found in the white matter of the frontal lobe. The number was significantly lower in the gray matter of the frontal lobe (p = 0.008) and the gray and white matter of the temporal lobes (p < 0.0001). The morphological changes observed in the encephalopathy group, propose a possible B19V involvement in the demyelination process.
HDL-C role in acquired aortic valve stenosis patients and its relationship with oxidative stress
(2019-08) Hofmanis, Juris; Hofmane, Dace; Svirskis, Simons; Mackevics, Vitolds; Tretjakovs, Peteris; Lejnieks, Aivars; Signorelli, Salvatore Santo; Department of Internal Diseases; Institute of Microbiology and Virology; Department of Human Physiology and Biochemistry
Background and objectives: Mechanical stress is currently considered as the main factor promoting calcific aortic valve stenosis (AS) onset. It causes endothelial damage and dysfunction. The chronic inflammatory process causes oxidative stress. Oxidative stress-induced high-density lipoprotein cholesterol (HDL-C) dysfunction is an important component of the development of AS. The aim of the study was to evaluate the role of HDL-C in AS patients in three severity grades and in relation to the biomarkers of oxidative stress, thioredoxin reductase 1 (TrxR1) and myeloperoxidase (MPO). Materials and Methods: 18 patients with mild, 19 with moderate. and 15 with severe AS were included in the study, and 50 individuals were enrolled in the control group. Stenosis severity was determined by echocardiography. The TrxR1 and MPO were analyzed by ELISA, and HDL-C by commercially available tests. Data were analyzed using GraphPad Prism 8. Results: HDL-C in AS patients vs. control substantially decreases and this decline was observed in all three AS severity groups: mild (p = 0.018), moderate (p = 0.0002), and severe (p = 0.004). In both the control and the stenosis group, the HDL-C was higher in women than in men. In comparison to control, the HDL-C level was lower in the AS group, and more pronounced in women (p = 0.0001) than in men (p = 0.049). A higher TrxR1 level was observed in patients with mild (p = 0.0001) and severe AS (p = 0.047). However, a clear correlation between TrxR1 and HDL-C was not obtained. Analysis of MPO showed differences in all severity grades vs. control (p = 0.024 mild stenosis; p = 0.002 moderate stenosis; p = 0.0015 severe stenosis). A negative correlation (p = 0.047; rp = −0.28) was found between MPO and HDL-C, which confirms the adverse effects of MPO resulting in HDL-C dysfunction. Conclusions: In this study, we justified HDL-C level association with AS development process. The results unequivocally substantiated the association between HDL-C and AS in all severity grades in women, but only in moderate AS for men, which we explained by the small number of men in the groups. The obtained correlation between the HDL-C and MPO levels, as well as the concurrent decrease in the HDL-C level and increase in the TrxR1 level, indicate in general an HDL-C association with oxidative stress in AS patients.
Human herpesvirus-6 and-7 in the brain microenvironment of persons with neurological pathology and healthy people
(2021-02-27) Skuja, Sandra; Svirskis, Simons; Murovska, Modra; Institute of Anatomy and Anthropology; Institute of Microbiology and Virology
During persistent human beta-herpesvirus (HHV) infection, clinical manifestations may not appear. However, the lifelong influence of HHV is often associated with pathological changes in the central nervous system. Herein, we evaluated possible associations between immunoex-pression of HHV-6,-7, and cellular immune response across different brain regions. The study aimed to explore HHV-6,-7 infection within the cortical lobes in cases of unspecified encephalo-pathy (UEP) and nonpathological conditions. We confirmed the presence of viral DNA by nPCR and viral antigens by immunohistochemistry. Overall, we have shown a significant increase (p < 0.001) of HHV antigen expression, especially HHV-7 in the temporal gray matter. Although HHV-infected neurons were found notably in the case of HHV-7, our observations suggest that higher (p < 0.001) cell tropism is associated with glial and endothelial cells in both UEP group and controls. HHV-6, predominantly detected in oligodendrocytes (p < 0.001), and HHV-7, predominantly detected in both astrocytes and oligodendrocytes (p < 0.001), exhibit varying effects on neural homeostasis. This indicates a high number (p < 0.001) of activated microglia observed in the temporal lobe in the UEP group. The question remains of whether human HHV contributes to neurological diseases or are markers for some aspect of the disease process.
Inflammatory Cytokine-Producing Cells and Inflammation Markers in the Synovium of Osteoarthritis Patients Evidenced in Human Herpesvirus 7 Infection
(2020) Groma, Valerija; Tarasovs, Mihails; Skuja, Sandra; Semenistaja, Sofija; Nora-Krukle, Zaiga; Svirskis, Simons; Murovska, Modra
A direct association between joint inflammation and the progression of osteoarthritis (OA) has been proposed, and synovitis is considered a powerful driver of the disease. Among infections implicated in the development of joint disease, human herpesvirus 7 (HHV-7) infection remains poorly characterized. Therefore, we assessed synovitis in OA patients; determined the occurrence and distribution of the HHV-7 antigen within the synovial membrane of OA-affected subjects; and correlated plasma levels of the pro-inflammatory cytokines tumor necrosis factor (TNF), interleukin-6 (IL-6), and TNF expressed locally within lesioned synovial tissues with HHV-7 observations, suggesting differences in persistent latent and active infection. Synovial HHV-7, CD4, CD68, and TNF antigens were detected immunohistochemically. The plasma levels of TNF and IL-6 were measured by an enzyme-linked immunosorbent assay. Our findings confirm the presence of persistent HHV-7 infection in 81.5% and reactivation in 20.5% of patients. In 35.2% of patients, virus-specific DNA was extracted from synovial membrane tissue samples. We evidenced the absence of histopathologically detectable synovitis and low-grade changes in the majority of OA patients enrolled in the study, in both HHV-7 PCR+ and HHV-7 PCR‒ groups. The number of synovial CD4-positive cells in the HHV-7 polymerase chain reaction (PCR)+ group was significantly higher than that in the HHV-7 PCR‒ group. CD4- and CD68-positive cells were differently distributed in both HHV-7 PCR+ and HHV-7 PCR‒ groups, as well as in latent and active HHV-7 infection. The number of TNF+ and HHV-7+ lymphocytes, as well as HHV-7+ vascular endothelial cells, was strongly correlated. Vascular endothelial cells, especially in the case of infection reactivation, appeared vulnerable. The balance between virus latency and reactivation is a long-term relationship between the host and infectious agent, and the immune system appears to be involved in displaying overreaction when a shift in the established equilibrium develops.
Inflammatory cytokine-producing cells and inflammation markers in the synovium of osteoarthritis patients evidenced in human herpesvirus 7 infection
(2020-09-01) Groma, Valerija; Tarasovs, Mihails; Skuja, Sandra; Semenistaja, Sofija; Nora-Krukle, Zaiga; Svirskis, Simons; Murovska, Modra; Joint Laboratory of Electron Microscopy; Institute of Anatomy and Anthropology; Department of Internal Diseases; Institute of Microbiology and Virology
A direct association between joint inflammation and the progression of osteoarthritis (OA) has been proposed, and synovitis is considered a powerful driver of the disease. Among infections implicated in the development of joint disease, human herpesvirus 7 (HHV-7) infection remains poorly characterized. Therefore, we assessed synovitis in OA patients; determined the occurrence and distribution of the HHV-7 antigen within the synovial membrane of OA-affected subjects; and correlated plasma levels of the pro-inflammatory cytokines tumor necrosis factor (TNF), interleukin-6 (IL-6), and TNF expressed locally within lesioned synovial tissues with HHV-7 observations, suggesting differences in persistent latent and active infection. Synovial HHV-7, CD4, CD68, and TNF antigens were detected immunohistochemically. The plasma levels of TNF and IL6 were measured by an enzyme-linked immunosorbent assay. Our findings confirm the presence of persistent HHV-7 infection in 81.5% and reactivation in 20.5% of patients. In 35.2% of patients, virusspecific DNA was extracted from synovial membrane tissue samples. We evidenced the absence of histopathologically detectable synovitis and low-grade changes in the majority of OA patients enrolled in the study, in both HHV-7 PCR+ and HHV-7 PCR‒ groups. The number of synovial CD4positive cells in the HHV-7 polymerase chain reaction (PCR)+ group was significantly higher than that in the HHV-7 PCR‒ group. CD4-and CD68-positive cells were differently distributed in both HHV-7 PCR+ and HHV-7 PCR‒ groups, as well as in latent and active HHV-7 infection. The number of TNF+ and HHV-7+ lymphocytes, as well as HHV-7+ vascular endothelial cells, was strongly correlated. Vascular endothelial cells, especially in the case of infection reactivation, appeared vulnerable. The balance between virus latency and reactivation is a long-term relationship between the host and infectious agent, and the immune system appears to be involved in displaying overreaction when a shift in the established equilibrium develops.
Interconnected Pathways : Exploring Inflammation, Pain, and Cognitive Decline in Osteoarthritis
(2024-11-06) Tarasovs, Mihails; Skuja, Sandra; Svirskis, Simons; Sokolovska, Lība; Vikmanis, Andris; Lejnieks, Aivars; Shoenfeld, Yehuda; Groma, Valērija; Department of Internal Diseases; Joint Laboratory of Electron Microscopy; Institute of Microbiology and Virology; Department of Orthopaedics
The relationship among inflammation, pain, and cognitive decline in osteoarthritis (OA) patients is complex and has not been sufficiently explored; therefore, we undertook this research to evaluate how OA-related inflammation and pain affect cognitive functions, as well as to examine the potential of urinary markers as indicators of these conditions. This study examined fifty OA patients through clinical and cognitive assessments, morphological analyses, urinary biomarkers, and bioinformatics. Morphologically, 24% of patients had moderate to high synovial inflammation, which was significantly correlated with depressive symptoms, pain intensity, and self-reported anxiety. The Montreal Cognitive Assessment indicated minimal decline in most patients but showed negative correlations with age and inflammation severity. Urinary TNF-α and TGF-β1 levels positively correlated with body mass index and pain and synovitis score and immune cell infiltration, respectively. In contrast, cartilage oligomeric matrix protein and C-telopeptides of type II collagen showed inverse correlations with pain duration and cognitive function, respectively. Distinct patient clusters with higher inflammation were identified and were associated with reported pain and depressive symptoms. Urinary TNF-α and TGF-β1 can serve as biomarkers reflecting inflammation and disease severity in OA. This study suggests that synovial inflammation may be linked to mental and cognitive health in some patient cohorts.
Mildronate and its Neuroregulatory Mechanisms : Targeting the Mitochondria, Neuroinflammation, and Protein Expression
(2013-08-04) Beitnere, Ulrika; Pupure, Jolanta; Isajevs, Sergejs; Rumaks, Juris; Svirskis, Simons; Dzirkale, Zane; Kalvinsh, Ivars
This review for the first time summarizes the data obtained in the neuropharmacological studies of mildronate, a drug previously known as a cardioprotective agent. In different animal models of neurotoxicity and neurodegenerative diseases, we demonstrated its neuroprotecting activity. By the use of immunohistochemical methods and Western blot analysis, as well as some selected behavioral tests, the new mechanisms of mildronate have been demonstrated: a regulatory effect on mitochondrial processes and on the expression of nerve cell proteins, which are involved in cell survival, functioning, and inflammation processes. Particular attention is paid to the capability of mildronate to stimulate learning and memory and to the expression of neuronal proteins involved in synaptic plasticity and adult neurogenesis. These properties can be useful in neurological practice to protect and treat neurological disorders, particularly those associated with neurodegeneration and a decline in cognitive functions.
Mildronate's protective effects in the peripheral nervous system : Stavudine-induced neuropathy and formalin-induced inflammation
(2010-01-01) Pupure, Jolanta; Rumaks, Juris; Isajevs, Sergejs; Korzakova, Olga; Puncule, Jelena; Svirskis, Simons; Kalviņš, Ivars; Kluša, Vija
Mildronate, previously known as a cardioprotective drug, recently was found to normalise mitochondrial processes by preventing the dysfunction of complex I in rat liver mitochondria. Previously we have shown also the ability of mildronate to prevent pathologies in the central nervous system by normalizing the expression of different signalling molecules in brain tissue. This allowed us to suggest that mildronate may possess a beneficial role also in peripheral nervous system pathologies. The present study was designed to assess the peripheral tissue damage caused by anti-HIV drug stavudine, as well as pain and inflammation caused by formalin. For this demonstration, we investigated the influence of mildronate: (1) on decreased myelin expression and increased neuron degeneration in rat sciatic nerve tissue caused by stavudine; and (2) on formalin-induced inflammation in mice. We found that mildronate protected the stavudine-induced degeneration of neurons in rat peripheral sciatic nerve without a significant influence on demyelination. In a formalin test, mildronate showed anti-inflammatory action comparable to that of indomethacin, a reference drug. The present results show that mildronate is capable of regulating peripheral nerve damage and peripheral inflammatory responses. We suggest that the multifunctional effects of mildronate can be attributed to its ability to regulate mitochondrial processes. The obtained data indicate protective effects of mildronate in different peripheral neurological pathologies.
Neuroprotective properties of mildronate, a small molecule, in a rat model of parkinson's disease
(2010-11) Klusa, Vija Z.; Isajevs, Sergejs; Svirina, Darja; Pupure, Jolanta; Beitnere, Ulrika; Rumaks, Juris; Svirskis, Simons; Jansone, Baiba; Dzirkale, Zane; Muceniece, Ruta; Kalvinsh, Ivars; Vinters, Harry V.
Previously, we have found that mildronate [3-(2,2,2-trimethylhydrazinium) propionate dihydrate], a small molecule with charged nitrogen and oxygen atoms, protects mitochondrial metabolism that is altered by inhibitors of complex I and has neuroprotective effects in an azidothymidine-neurotoxicity mouse model. In the present study, we investigated the effects of mildronate in a rat model of Parkinson's disease (PD) that was generated via a unilateral intrastriatal injection of the neurotoxin 6-hydroxydopamine (6-OHDA). We assessed the expression of cell biomarkers that are involved in signaling cascades and provide neural and glial integration: the neuronal marker TH (tyrosine hydroxylase); ubiquitin (a regulatory peptide involved in the ubiquitin-proteasome degradation system); Notch-3 (a marker of progenitor cells); IBA-1 (a marker of microglial cells); glial fibrillary acidic protein, GFAP (a marker of astrocytes); and inducible nitric oxide synthase, iNOS (a marker of inflammation). The data show that in the 6-OHDA-lesioned striatum, mildronate completely prevented the loss of TH, stimulated Notch-3 expression and decreased the expression of ubiquitin, GFAP and iNOS. These results provide evidence for the ability of mildronate to control the expression of an array of cellular proteins and, thus, impart multi-faceted homeostaticmechanisms in neurons and glial cells in a rat model of PD. We suggest that the use of mildronate provides a protective effect during the early stages of PD that can delay or halt the progression of this neurodegenerative disease.
Peripheral Blood Mononuclear Cells' Proliferative Response to Human Parvovirus B19 Antigens in Patients with Rheumatoid Arthritis
(2016-08-01) Bratslavska, Olga; Kozireva, Svetlana; Kadisa, Anda; Svirskis, Simons; Pavlova, Jeļena; Lejnieks, Aivars; Murovska, Modra; Institute of Microbiology and Virology; Department of Internal Diseases
This study aimed to determine peripheral blood mononuclear cells' (PBMC) proliferative response to parvovirus B19 (B19) antigens in rheumatoid arthritis (RA) patients and possible changes in proliferative response due to chemotherapy. Serum and blood samples of 52 RA patients and 25 sex and age matched healthy individuals were examined for the presence of anti-B19 IgG and IgM class antibodies and virus specific DNA sequence by the recomLine B19 test and nested polymerase chain reaction, respectively. The PBMC proliferative activity was estimated on the 3rd and 6th day of PBMC cultivation in the presence of virus and B19 VP1/VP2 peptide, using thymidine incorporation assay. On the 3rd day, PBMC response to B19 antigens was detected in 74.1% RA patients with active, in 44.8%-with remote and in 40%-with latent stage of persistent B19 infection, while in the control group the response was observed only in two individuals with active viral infection. On the 6th day, the response was found in 50% RA patients with active, 68.9%-with remote and in 80%-with latent stage of latent persistent infection as well as in 41.1% remotely infected control individuals. The highest PBMC mean stimulation indices were detected in the RA patients and control persons with active infection as well as in RA patients with latent stage of persistent viral infection. On the 3rd and 6th day, strong proliferative response was significantly more frequently observed in RA patients not receiving methotrexate treatment, compared to the patients receiving methotrexate treatment in different combinations with other drugs. RA patients had more frequent and faster response to B19 antigens than apparently healthy persons.
Persistent Roseoloviruses Infection in Adult Patients with Epilepsy
(2020-05-11) Rasa-Dzelzkaleja, Santa; Gravelsina, Sabine; Chapenko, Svetlana; Nora-Krukle, Zaiga; Svirskis, Simons; Suna, Normunds; Kashuba, Elena; Karelis, Guntis; Murovska, Modra
Background: Human herpesviruses (HHV)-6A, HHV-6B and HHV-7 are considered to be involved in the pathogenesis of epilepsy, a common neurological disorder. The objective of this study was to determine the association of roseoloviruses infection with epilepsy. Methods: 53 epilepsy patients and 104 ordinary blood donors were analyzed to determine presence of virus-specific antibodies by enzyme-linked immunosorbent assay (ELISA) and immunofluorescence assay (IFA), genomic sequences, viral load and gene expression by polymerase chain reactions (PCRs) and restriction analysis, HHV-6 protein expression by IFA and level of cytokines by ELISA. Results: Roseoloviruses genomic sequences in DNA samples from whole blood were found in 86.8% of patients versus 54.8% of controls and active infection was revealed only in patients with epilepsy (19.6% of roseolovirus-positive patients). Significantly higher viral load and more frequent gene expression was detected in patients compared to the controls. HHV-6-encoded protein expression was demonstrated in 53.3% of patients with previously detected HHV-6 DNA. Changes in level of cytokines were determined in patients with elevated viral load compared to the patients without elevated viral loads and to the controls. Conclusions: Results on frequent active HHV-6 and HHV-7 infection in epilepsy patient’ peripheral blood indicate on possible involvement of these viruses in the disease development.
Plasma levels of Th17-associated cytokines and selenium status in autoimmune thyroid diseases
(2021-09) Zaķe, Tatjana; Kalere, Ieva; Upmale-Engela, Sabīne; Svirskis, Simons; Gersone, Gita; Skesters, Andrejs; Groma, Valērija; Konrāde, Ilze; Department of Internal Diseases; Institute of Microbiology and Virology; Department of Human Physiology and Biochemistry; Bioķīmijas zinātniskā laboratorija; Institute of Anatomy and Anthropology
INTRODUCTION: The contribution of Th17 cytokines to autoimmune thyroid disease (AITD) is generally accepted. However, the roles of Th17 cells in the initiation and progression of Hashimoto's thyroiditis (HT) and Graves' disease (GD) remain unclear. Selenium deficiency, along with genetic predisposition and environmental factors, may have a role in thyroid autoimmunity. AIM: We aimed to assess (1) the Th17 immune response by measuring plasma levels of Th17- and Treg-associated cytokines and (2) the selenium status in treatment-naïve Latvian patients with newly diagnosed GD or HT. METHODS: Eleven GD patients, 41 HT patients, and 26 healthy subjects were recruited for this study. Plasma levels of IL-17a, IL-22, IL-23, IL-6, and IL-10 were detected by xMAP technology, while selenium was detected fluorometrically. RESULTS AND CONCLUSIONS: No significant differences in IL-17a, IL-22, IL-23, IL-6, or IL-10 levels were found among the HT patients, GD patients, and controls. In the HT patients, IL-17a levels were positively correlated with IL-22, IL-23, IL-6, and IL-10, while IL-22 was correlated with IL-6, IL-23, and IL-10. In the GD patients, IL-17a levels were positively correlated with IL-22, IL-23, and IL-10; IL-22 was positively correlated with IL-23, IL-6, and IL-10; FT3 was positively correlated with IL-17a, IL-23, and IL-10; and FT4 was positively correlated with IL-17a and IL-10 levels. Plasma selenium levels were negatively correlated with antithyroid peroxidase antibody titers in the HT patients. Although no difference in selenium levels was observed between the AITD patients and controls, the selenium status of the Latvian patients with GD or HT was at a suboptimal level.
Potential of activin b as a clinical biomarker in myalgic encephalomyelitis/chronic fatigue syndrome (Me/cfs)
(2021-08-11) Gravelsina, Sabine; Nora‐krukle, Zaiga; Vilmane, Anda; Svirskis, Simons; Vecvagare, Katrine; Krūmiņa, Angelika; Murovska, Modra; Institute of Microbiology and Virology; Department of Infectology
Reliable serum biomarkers are of immense need for diagnostic purposes of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)—a disabling and complex disease for which diagnosis is mainly based on clinical symptoms. The aim of this study was to evaluate a possible diagnostic potential of activin B by directly comparing 134 cases of ME/CFS with 54 healthy controls. Analyses of human activin B level in plasma samples were performed using a validated human activin B ELISA assay. The results of the study show that activin B levels did not differ statistically significantly between ME/CFS patients and healthy controls (p = 0.6511). No gender or age‐related differences in activin B levels were observed in the ME/CFS group and healthy controls. The level of activin B tended to decrease with increasing visual analogue scale score (r = −0.2004; p = 0.5085) nevertheless the results obtained so far does not support the clinical utility of activin B as a bi-omarker for ME/CFS.
Presence of B19V in Patients with Thyroid Gland Disorders
(2019) Gravelsina, Sabine; Nora-Krukle, Zaiga; Svirskis, Simons; Cunskis, Egils; Murovska, Modra
Background and Objectives: Viral infections are frequently cited as a major environmental factor implicated in thyroid gland diseases. This work aimed to estimate the presence of B19V infection in patients with thyroid gland disorders. Materials and Methods: Thyroid gland tissue and blood samples of 50 patients with autoimmune thyroid gland diseases (AITDs), 76 patients with non-autoimmune thyroid gland diseases (non-AITDs), and 35 deceased subjects whose histories did not show any autoimmune or thyroid diseases (control group) were enrolled in the study. Virus-specific IgM and IgG were detected using ELISA, and the presence and viral load of B19V in the tissue and blood were detected using PCRs. Results: B19V IgG antibodies were detected in 35/50 AITDs patients and in 51/76 non-AITDs patients, and B19V IgM antibodies were detected in 1/50 patients with AITDs and in none of the 76 patients with non-AITDs. The B19V NS sequence was found in the tissue DNA of 10/50 patients with AITDs, in 30/76 with non-AITDs, and in 1/35 control group individuals. The median B19V load in the tissue of patients with AITDs and non-AITDs was 423.00 copies/µg DNA (IQR: 22.50–756.8) and 43.00 copies/µg DNA (IQR: 11.50–826.5), respectively. The viral load in one of the 35 nPCR B19V-positive thyroid tissue samples from the deceased subjects was 13.82 copies/µg DNA. The viral load in the tissue of patients with AITDs was higher than in whole blood, which possibly indicates B19V persistency in thyrocytes (p = 0.0076). Conclusion: The fact that the genoprevalence of B19V NS was significantly higher in patients with non-AITDs compared to the control group and in the thyroid gland tissue of patients with AITDs, and that the non-AITDs viral load was higher than in tissue derived from the control group individuals, suggest the possibility that B19V infection could be involved in the development of thyroid gland diseases.

Browsing by Author "Svirskis, Simons"

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