0000000000122548
AUTHOR
Tatjana Sjakste
showing 29 related works from this author
Identification of a novel candidate locus for juvenile idiopathic arthritis at 14q13.2 in the Latvian population by association analysis with microsa…
2010
To identify novel juvenile idiopathic arthritis (JIA) susceptibility loci, a 270 kb genomic region encompassing FAM177A1, KIAA0391, and PSMA6 genes was genotyped in 97 oligoarthritis (JIoA) and 50 polyarthritis (JIpA) patients and 230 individuals without autoimmune disorders by five microsatellites (MS) previously described as HSMS markers of the 14q13.2 region. Direct sequencing revealed two variable components of the (CAA)(n)(A)(m) motif in HSMS602 marker (FAM177A1 gene). Repeat (AC)(5)AT(AC)(n) of the HSMS701 (KIAA0391 gene) was variable in the Latvian population only in its downstream part. Allele (AC)(5)AT(AC)(15) of HSMS701 was found to be strongly associated with JIA (p = 4.91 x 10(-…
Putative role of nitric oxide synthase isoforms in the changes of nitric oxide concentration in rat brain cortex and cerebellum following sevoflurane…
2005
We have previously observed an increase in nitric oxide (NO) content in rat brain cortex following halothane, sevoflurane or isoflurane anaesthesia. This study was undertaken in order to determine whether isoform-specific nitric oxide synthase (NOS) inhibitors and inducers could modify these increases in NO contents. Rats were subjected to isoflurane and sevoflurane anaesthesia with concomitant administration of neuronal nitric oxide synthase (nNOS) inhibitor 7-Nitro-indazole (7-NI), inducible nitric oxide synthase (iNOS) inhibitor 2-amino-5,6-dihydro-6-methyl-4H-1,3-thiazine (AMT) or lipopolysaccharide. NO concentration in different organs was measured by electron paramagnetic resonance (E…
Tight DNA-protein complexes isolated from barley seedlings are rich in potential guanine quadruplex sequences
2020
Background The concept of chromatin domains attached to the nuclear matrix is being revisited, with nucleus described as a set of topologically associating domains. The significance of the tightly bound to DNA proteins (TBP), a protein group that remains attached to DNA after its deproteinization should be also revisited, as the existence of these interactions is in good agreement with the concept of the topologically associating domain. The work aimed to characterize the DNA component of TBP isolated from barley seedlings. Methods The tight DNA-protein complexes from the first leaves, coleoptiles, and roots of barley seedlings were isolated by purification with chromatography on nitrocell…
Evaluation of the RYR1 gene genetic diversity in the Latvian White pig breed
2016
The ryanodine receptor 1 (RYR1) is a calcium ion channel in the sarcoplasmic reticulum of skeletal muscle. Multiple polymorphic loci have been identified in the RYR1 gene in human and animals and some of them are associated with certain phenotypes. However, there are still few data on the RYR1 genetic variability in pig and only the missense mutation Arg615Cys, associated with the malignant hyperthermia, porcine stress syndrome and meat quality, has been studied in several commercial and local breeds. Aim. To genotype the rs344435545 (C1972T, Arg615Cys), rs196953058 (T8434C, Phe2769Leu) and rs323041392 (G12484A, Asp4119Asn) in the Latvian local pig breed Latvian White and to evaluate the ev…
Development-dependent changes in the tight DNA-protein complexes of barley on chromosome and gene level
2008
Abstract Background The tightly bound to DNA proteins (TBPs) is a protein group that remains attached to DNA with covalent or non-covalent bonds after its deproteinisation. The functional role of this group is as yet not completely understood. The main goal of this study was to evaluate tissue specific changes in the TBP distribution in barley genes and chromosomes in different phases of shoot and seed development. We have: 1. investigated the TBP distribution along Amy32b and Bmy1 genes encoding low pI α-amylase A and endosperm specific β-amylase correspondingly using oligonucleotide DNA arrays; 2. characterized the polypeptide spectrum of TBP and proteins with affinity to TBP-associated D…
An Intergenic rs9275596 Polymorphism on Chr. 6p21 Is Associated with Multiple Sclerosis in Latvians
2020
Background and objectives: Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system, leading to demyelination of neurons and potentially debilitating physical and mental symptoms. The disease is more prevalent in women than in men. The major histocompatibility complex (MHC) region has been identified as a major genetic determinant for autoimmune diseases, and its role in some neurological disorders including MS was evaluated. An intergenic single-nucleotide polymorphism (SNP), rs9275596, located between the HLA-DQB1 and HLA-DQA2 genes, is in significant association with various autoimmune diseases according to genome-wide association studies (GWASs). A cumulat…
Effects of an Antimutagenic 1,4-Dihydropyridine AV-153 on Expression of Nitric Oxide Synthases and DNA Repair-related Enzymes and Genes in Kidneys of…
2016
Development of complications of diabetes mellitus (DM), including diabetic nephropathy, is a complex multi-stage process, dependent on many factors including the modification of nitric oxide (NO) production and an impaired DNA repair. The goal of this work was to study in vivo effects of 1,4-dihydropyridine AV-153, known as antimutagen and DNA binder, on the expression of several genes and proteins involved in NO metabolism and DNA repair in the kidneys of rats with a streptozotocin (STZ)-induced model of DM. Transcription intensity was monitored by means of real-time RT-PCR and the expression of proteins by immunohistochemistry. Development of DM significantly induced PARP1 protein express…
Juvenile idiopathic arthritis subtype- and sex-specific associations with genetic variants in the PSMA6/PSMC6/PSMA3 gene cluster.
2014
BackgroundThe ubiquitin proteasome system plays an exceptional biological role in the antigen processing and immune response and it could potentially be involved in pathogenesis of many immunity-related diseases, including juvenile idiopathic arthritis (JIA).MethodsThe PSMB5 (rs11543947), PSMA6 (rs2277460, rs1048990), PSMC6 (rs2295826, rs2295827), and PSMA3 (rs2348071) proteasomal genes were genotyped on JIA subtype- and sex-specific association; plasma proteasome levels was measured in patients having risk and protective four-locus genotypes and eventual functional significance of allele substitutions was evaluated in silico.ResultsLoci rs11543947 and rs1048990 were identified as disease n…
Association of microsatellite polymorphisms of the human 14q13.2 region with type 2 diabetes mellitus in Latvian and Finnish populations.
2007
A polymorphic microsatellite in intron 6 of the human proteasome core particle PSMA6 gene (HSMS006), and four other microsatellites localized upstream on human chromosome 14q13.2 (HSMS801, HSMS702, HSMS701, HSMS602), were genotyped in 104 type 2 diabetic patients and 129 age-matched control subjects from Latvia and replicated in 91 type 2 diabetic patients and 88 age-matched healthy control subjects from the Botnia Study in Finland. In type 2 diabetic patients from both populations the HSMS006 (TG)22 allele was two times more frequent compared to the control group. In the Latvian population the (CAA)8 allele of the HSMS602 marker was less frequent in the diabetic group, as was the (AC)24 al…
New 1,4-Dihydropyridines Down-regulate Nitric Oxide in Animals with Streptozotocin-induced Diabetes Mellitus and Protect Deoxyribonucleic Acid agains…
2015
Diabetes mellitus (DM) and its complications cause numerous health and social problems throughout the world. Pathogenic actions of nitric oxide (NO) are responsible to a large extent for development of complications of DM. Search for compounds regulating NO production in patients with DM is thus important for the development of pharmacological drugs. Dihydropyridines (1,4-DHPs) are prospective compounds from this point of view. The goals of this study were to study the in vivo effects of new DHPs on NO and reactive nitrogen and oxygen species production in a streptozotocin (STZ)-induced model of DM in rats and to study their ability to protect DNA against nocive action of peroxynitrite. STZ…
1,4-Dihydropyridine derivatives without Ca2+-antagonist activity up-regulatePsma6mRNA expression in kidneys of intact and diabetic rats
2015
Impaired degradation of proteins by the ubiquitin-proteasome system (UPS) is observed in numerous pathologies including diabetes mellitus (DM) and its complications. Dysregulation of proteasomal degradation might be because of altered expression of genes and proteins involved in the UPS. The search for novel compounds able to normalize expression of the UPS appears to be a topical problem. A novel group of 1,4-dihydropyridine (1,4-DHP) derivatives lacking Ca2+-antagonists activities, but capable to produce antidiabetic, antioxidant and DNA repair enhancing effects, were tested for ability to modify Psma6 mRNA expression levels in rat kidneys and blood in healthy animals and in rats with str…
Influence of metformin on GLUT1 gene and protein expression in rat streptozotocindiabetes mellitusmodel
2010
Metformin improves hyperglycaemia via mechanisms which include activation of AMP-activated protein kinase (AMPK). Recent findings indicate that some metabolic actions of metformin occur also by AMPK-independent mechanisms.To study the action of metformin on expression of GLUT1 glucose transporter in rat streptozotocin model of diabetes mellitus.Streptozotocin-induced rats were treated with metformin while monitoring parameters of carbohydrate and lipid metabolism. GLUT1 mRNA and protein expression in kidneys, heart, liver and muscles were studied by means of real time quantitative RT-PCR and immunohistochemistry correspondingly.Metformin treatment decreased glucose concentration, glycated h…
Association of obesity with proteasomal gene polymorphisms in children.
2013
The aim of this study was to ascertain possible associations between childhood obesity, its anthropometric and clinical parameters, and three loci of proteasomal genes rs2277460 (PSMA6c.-110C>A), rs1048990 (PSMA6c.-8C>G), and rs2348071 (PSMA3c. 543+138G>A) implicated in obesity-related diseases. Obese subjects included 94 otherwise healthy children in Latvia. Loci were genotyped and then analyzed using polymerase chain reactions, with results compared to those of 191 nonobese controls.PSMA3SNP frequency differences between obese children and controls, while not reaching significance, suggested a trend. These differences, however, proved highly significant (P<0.002) in the subset…
Analysis of the Single-Nucleotide Polymorphism in the 5′UTR and Part of Intron I of the Sheep MSTN Gene
2011
The myostatin (MSTN) gene region encompassing the 5′UTR and part of intron I was sequenced in animals of two herds of Latvian Darkhead sheep to extend data on the ovine MSTN gene polymorphism and to provide information useful for local breed conservation. Two and four polymorphic loci were revealed in the 5′UTR and intron I. Four and five local haplotypes were constructed, respectively. The genotyping data obtained and that previously reported for the same genomic region were combined in one dataset for the haplotype analysis. Recombination events were detected between loci (c.−40, c.−37) in the 5′UTR and (c.373+18, c.373+101) and (c.373+101, c.373+241) in intron I. Single-nucleotide polymo…
Modifications of expression of genes and proteins involved in DNA repair and nitric oxide metabolism by carbatonides [disodium-2,6-dimethyl-1,4-dihyd…
2017
Abstract Studies on the pathogenesis of diabetes mellitus complications indicate that the compounds reducing free radicals and enhancing DNA repair could be prospective as possible remedies. Carbatonides, the disodium-2,6-dimethyl-1,4- dihydropyridine-3,5-bis(carbonyloxyacetate) derivatives, were tested for these properties. EPR spectroscopy showed that metcarbatone was an effective scavenger of hydroxyl radicals produced in the Fenton reaction, etcarbatone, and propcarbatone were less effective, styrylcarbatone was ineffective. UV/VIS spectroscopy revealed that styrylcarbatone manifested a hyperchromic effect when interacting with DNA, while all other carbatonides showeda hypochromic effec…
Changes in glucose transporter expression and nitric oxide production are associated with liver injury in diabetes
2015
In diabetes mellitus (DM), both hyperglycaemia and hyperlipidaemia can initiate accumulation of fat in the liver, which might be further mediated by inducible nitric oxide synthase. We have studied changes in GLUT1, nitric oxide (NO(·)) concentration and liver damage in two rat DM models. STZ model was induced by strepozotocin 50 mg/kg. HS model was induced by high-fat diet and 30 mg/kg streptozotocin. GLUT1 expression was studied by means of real-time RT-PCR and immunohistochemistry. Production of NO(·) was monitored by means of erythrocyte sedimentation rate spectroscopy of Fe-DETC-NO complex. Liver damage was assessed using histological activity index (HAI). NO(·) concentration was incre…
Disease-Specific and Common HLA and Non-HLA Genetic Markers in Susceptibility to Rheumatoid Arthritis, Type 1 Diabetes Mellitus and Multiple Sclerosis
2016
Autoimmune diseases cause numerous health and social problems throughout the world. The common spectrum of autoimmune diseases affect the majority of tissues within the body, including pancreatic beta cells in type 1 diabetes (T1DM), myelin surrounding nerve axons in Multiple sclerosis (MS) and synovial joint antigens in Rheumatoid Arthritis (RA). The diseases are likely caused by a complex interaction between multiple HLA- and non- HLA related genes and environmental factors. The well documented co-clustering of autoimmune diseases within families and individuals, together with apparent sharing of number risk genes between the diseases suggests at least some common mechanisms of autoimmune…
Association Study of Genetic Variants in the 14q11 - 14q13 Proteasomal Genes Cluster with Juvenile Idiopathic Arthritis (JIA) in Latvian Population
2009
Association Study of Genetic Variants in the 14q11 - 14q13 Proteasomal Genes Cluster with Juvenile Idiopathic Arthritis (JIA) in Latvian Population The possible role of proteasomes in the development of autoimmune diseases was hypothesised after discovery of the involvement of proteasomal LMP2 and LMP7 subunits in antigene processing. The objective of this study was to determine the association between allelic variants of the genes encoding proteasomal proteins PSME1, PSME2 and PSMA6 and juvenile idiopathic arthritis (JIA) in the Latvian population. One Indel G-4543 CA-4544 →GA and four SNPs related to the PSMA6 gene (A-2486 →G and C-1910 →T, upstream promoter, C-110 →A of promoter, and C-8…
Tightly bound to DNA proteins: possible universal substrates for intranuclear processes.
2011
Tightly bound to DNA proteins (TBPs) are a protein group that remains attached to DNA after its deproteinization by phenol, chloroform or salting-out. TBP are bound to DNA with covalent phosphotriester or non-covalent ion and hydrogen bonds. They appear to be a vast protein group involved in numerous intranuclear processes. The TBPs fraction co-purified with DNA deproteinized by mild procedures is extremely heterogeneous, tissue and species-specific. The protein fraction co-purified with DNA after harsh deproteinization procedures appears to be formed from few polypeptides common to different species and tissues. Interaction sites between DNA and TBPs depend on the physiological status of t…
Correction of glycaemia and GLUT1 level by mildronate in rat streptozotocin diabetes mellitus model
2011
Anti-ischaemic drug mildronate suppresses fatty acid metabolism and increases glucose utilization in myocardium. It was proposed that it could produce a favourable effect on metabolic parameters and glucose transport in diabetic animals. Rats with streptozotocin diabetes mellitus were treated with mildronate (100 mg/kg daily, per os, 6 weeks). Therapeutic effect of mildronate was monitored by measuring animal weight, concentrations of blood glucose, insulin, blood triglycerides, free fatty acids, blood ketone bodies and cholesterol, glycated haemoglobin per cent (HbA1c%) and glucose tolerance. GLUT1 mRNA and protein expression in kidneys, heart, liver and muscles were studied by means of re…
PSMA6 (rs2277460, rs1048990), PSMC6 (rs2295826, rs2295827) and PSMA3 (rs2348071) genetic diversity in Latvians, Lithuanians and Taiwanese
2014
PSMA6 (rs2277460, rs1048990), PSMC6 (rs2295826, rs2295827) and PSMA3 (rs2348071) genetic diversity was investigated in 1438 unrelated subjects from Latvia, Lithuania and Taiwan. In general, polymorphism of each individual locus showed tendencies similar to determined previously in HapMap populations. Main differences concern Taiwanese and include presence of rs2277460 rare allele A not found before in Asians and absence of rs2295827 rare alleles homozygotes TT observed in all other human populations. Observed patterns of SNPs and haplotype diversity were compatible with expectation of neutral model of evolution. Linkage disequilibrium between the rs2295826 and rs2295827 was detected to be c…
Genetic variations in the PSMA6 and PSMC6 proteasome genes are associated with multiple sclerosis and response to interferon‑β therapy in Latvians
2021
Several polymorphisms in genes related to the ubiquitin-proteasome system exhibit an association with pathogenesis and prognosis of various human autoimmune diseases. Our previous study reported the association between multiple sclerosis (MS) and the PSMA3-rs2348071 polymorphism in the Latvian population. The current study aimed to evaluate the PSMA6 and PSMC6 genetic variations, their interaction between each other and with the rs2348071, on the susceptibility to MS risk and response to therapy in the Latvian population. PSMA6-rs2277460, -rs1048990 and PSMC6-rs2295826, -rs2295827 were genotyped in the MS case/control study and analysed in terms of genotype-protein correlation network. The …
Spectrophotometric study of DNA interactions with ftorafur and its elementoorganic derivatives
2017
ABSTRACTFtorafur is an antimetabolite antitumour drug successfully used for treatment of various tumours. It is generally accepted that ftorafur is converted to 5-fluoruracil. However, some data indicate direct interactions of the compound with DNA. To test this hypothesis we have performed spectrophotometric study of DNA interactions of ftorafur and some of its elementoorganic derivatives with DNA. UV-VIS spectra of the tested compounds were recorded in absence and presence of increasing amounts of DNA. DNA caused a hypochromic effect in spectra of ftorafur, similar, but weaker effect was observed in 5-fluoruracil spectra. Trimethylgermyl derivative of ftorafur manifested a higher DNA-bind…
Evaluation of proteasomal gene polymorphisms in Lithuanian patients with asthma.
2014
To investigate polymorphisms of proteasomal genes PSMA6 (rs1048990 and rs2277460), PSMC6 (rs2295826 and rs2295827) and PSMA3 (rs2348071) in Lithuanian patients with asthma.One-hundred forty-six asthma patients and 150 control subjects were studied. DNA was extracted from peripheral blood samples. Five single nucleotide polymorphisms (SNP's) of the three proteasomal genes were analyzed using allele-specific amplification or the cleaved amplified polymorphic sequence method.While certain alleles and genotypes of PSMA6 rs2277460 and rs1048990 and PSMA3 rs2348071 SNP's occurred more frequently in asthma patients than in controls, no statistically significant differences in alleles or genotypes …
The Burden of Allergic Asthma in Children: A Landscape Comparison Based on Data from Lithuanian, Latvian, and Taiwanese Populations
2012
Asthma is one of the most common chronic respiratory diseases with an increasing prevalence and financial burden worldwide. This disease affects individuals in all countries and all ethnic groups; however, prevalence rates of asthma have been reported to vary significantly between different regions. To understand the origin of asthma and to manage it effectively, it is necessary to analyze the genetic and environmental factors that cause these geographic differences. Therefore, we aimed to review published data from the investigations of asthma patients in Eastern Europe, represented by Latvia and Lithuania, and of patients from Eastern Asia represented by Taiwan. We hope that some of the c…
Analysis of plant diversity with retrotransposon-based molecular markers
2010
Retrotransposons are both major generators of genetic diversity and tools for detecting the genomic changes associated with their activity because they create large and stable insertions in the genome. After the demonstration that retrotransposons are ubiquitous, active and abundant in plant genomes, various marker systems were developed to exploit polymorphisms in retrotransposon insertion patterns. These have found applications ranging from the mapping of genes responsible for particular traits and the management of backcrossing programs to analysis of population structure and diversity of wild species. This review provides an insight into the spectrum of retrotransposon-based marker syst…
Transcription- and apoptosis-dependent long-range distribution of tight DNA-protein complexes in the chicken alpha-globin gene.
2008
The proteins tightly bound to DNA (TBP) are a group of proteins that remain attached to DNA with covalent or noncovalent bonds after its deproteinization, and have been hypothesized to be involved in regulation of gene expression. To investigate this question further, oligonucleotide DNA arrays were used to determine the distribution of tightly bound proteins along a 100-kb DNA fragment surrounding the chicken alpha-globin gene domain in DNA from chicken erythrocytes, liver, and AEV-transformed HD3 (erythroblast) cells in different physiological conditions. DNA was fractionated into TBP-free (F) and TBP-enriched (R) fractions by separation on nitrocellulose, and these fractions were used as…
Functional Significance of Microsatellite Markers
2014
The review summarizes literature data on the positive results of association studies between the length of microsatellite repeats and predisposition to pathologies. Actually, the data can be classified according to the localization of the microsatellite: in the gene promoter, in the part of exon 1 coding the signal sequence, in gene introns, in the coding areas of genes, and in 3'-untranslated regions. The functional significance of microsatellite length changes can be evaluated in many cases. The authors came up to the conclusion that further studies on microsatellite associations with diseases remain prospective as they reflect changes in the gene functional activity.
Comparison of the Effects of Glibenclamide on Metabolic Parameters, GLUT1 Expression, and Liver Injury in Rats With Severe and Mild Streptozotocin-In…
2012
Background and Objective. Glucose transport via GLUT1 protein could be one of additional mechanisms of the antidiabetic action of sulfonylureas. Here, the GLUT1 gene and the protein expression was studied in rats in the course of severe and mild streptozotocin-induced diabetes mellitus and under glibenclamide treatment. Material and Methods. Severe and mild diabetes mellitus was induced using different streptozotocin doses and standard or high fat chow. Rats were treated with glibenclamide (2 mg/kg daily, per os for 6 weeks). The therapeutic effect of glibenclamide was monitored by measuring several metabolic parameters. The GLUT1 mRNA and the protein expression in the kidneys, heart, and l…