Ispitivanje genotoksičnosti 8-CI-cAMP u dva in vivo testa na miševima soja BALB/c

The antitumor agent 8-CI-cAMP (8-chloro-cyclic adenosine monophosphate) is the most potent site-selective analogue of cAMP. It acts primarily by selective down-regulation of regulatory sub-units of cAMP-dependent protein kinases. This results in reversion of the neoplastic predominance of PK-I type over PK-II type protein kinase back to the ratio more typical to of the normal phenotype. The differential activity of 8-CI-cAMP towards protein kinase isozymes leads to inhibition of cell growth, differentiation and neoplastic reversion of a wide variety of cancer cell lines. Since 8-CI-cAMP has been investigated as a new potential anticancer drug with no previous studies of its mutagenic and clastogenic effects, we have investigated the genotoxicity of 8-CI-cAMP. Genotoxic effects were estimated by the bone marrow micronucleus assay and the occurrence of morphological chromosome lesions in adult mice (BALB/c strain). 8-CI-cAMP was administered intraperitoneally (i.p) in three doses, 10 mg/kg b.w.; 90 mg/kg b.w. and 160 mg/kg b.w., with saline solution as a negative control and cyclophosphamide, a known mutagen and clastogen as a positive control at twenty four hour intervals during a seven day period. Micronucleus test results showed a consistent dose-dependent pattern. Thus, with increase of the dose (10 mg/kg b.w., 90 mg/kg b. w. and 160 mg/kg b.w.) there was an increase in the frequency of micronuclei in polychromatic erythrocytes (4.88 ± 0.35; 8.32 ± 0.57; 11.75 ± 0.37) compared to the negative control (2.04 ±0.28). Using chromosome aberrations as an indicator of genotoxic potential, 8-CI-cAMP in all three doses (10 mg/kg b.w.; 90 mg/kg b.w. and 160 mg/kg b.w.) produced karyotype transformation of mouse bone marrow cells. 8-CI-cAMP induced structural chromosome aberrations as lesions (2.87 0.14; 4,37 0.14 i 5.25 0.35), interruptions (9±0.1; 12.37±0.26 i 13.37±0,33), ring chromosomes (3.62 0.21; 2.5±0,07 i 2.5±0.07), accentrics (10±0.49; 16.5±0.45 i 18.37±0.54) and Robertsonian translocations (7.12±0.26 ;9 0.1 i 11.24 ±0.18) as well as numerical chromosome aberrations of the aneuploidal type (36 5± 0.74; 60.25±0.24 i 85.62±0.5) and polyploidy (7±0.24; 5.5+0.27 / 5.87±0.14). These results demonstrate the genotoxic potential of the investigated substance.Antitumorski preparat 8-CI-cAMP (8-hloro-ciklični adenozin monofosfat) je najpotentniji analog AMP koji deluje primamo na modulaciju cAMP - zavisne protein kinaze dovodeći do inhibicije regulatornih subjedinica. Rezultat takvog dejstva je smanjenje dominantnog tipa PK-I protein kinaze u kanceroznim ćelijama nad drugim tipom PK-II protein kinaze, u odnosu na međusobni nivo PK-I I PK-II koji se nalaze u normalnim ćelijama. Ciklični 8-CI-AMP je analog koji ima izuzetnu anti-neoplastičnu aktivnost sa efektom restauracije, diferencijacije i reverzne transformacije kanceroznih ćelija miša i čoveka. Sa stanovišta mogućeg mutagenog i genotoksičnog efekta 8-CI-cAMP nije dovoljno istražen. Zato je i cilj ovog rada bio da se primenom citogenetičkog i mikronukleus testa, na ćelijama kostne srži miša BALB/c soja, ispita genotoksični efekat 8-CI-cAMP u tri dozna režima (10 mg/kg t.m; 90 mg/kg t.m. i 160 mg/kg t.m.). Pored eksperimentalnih grupa životinja u eksperimentu su uspostavljene i negativna kontrola koju su činile jedinke tretirane sa fiziološkim rastvorom, kao i pozitivna kontrola životinja koje su tretirane sa poznatim klastogenom i mutagenom-ciklofosfamidom u dozi od 40 mg/kg t.m. Rezultati ispitivanja pokazuju konzistetni dozno-zavisni obrazac primenom mikronukleus testa. Sa rastom doze (10 mg/kg t.m ; 90 mg/kg t.m. i 160 mg/kg t.m.) raste i broj mikronukleusa u polihromatofilnim eritrocitima (4,88 ±0,35; 8,32±0,57; 11,75±0,37) u odnosu na kontrolnu grupu (2,04±0,28). Testirane rastuće doze 8-CI-cAMP u citogenetičkom testu in vivo pokazuju sposobnost transformacije kariotipa ćelija kostne srži BALB/c miševa u vidu struktumih hromozomskih aberacija tipa lezija (2,87±0,14; 4,37±0,14; 5,25±0,35), prekida (90,1; 12,37±0,26; 13,37±0,33), ring hromozoma (3,62+0,21; 2,5±0,07; 2,5±0,07), acentrika (100,49; 16,5±0,45; 18,37±0,54) i Robersonovih translokacija (7,12±0,26; 90,1; 11,24±0,18) i numeričkih hromozomskih aberacija tipa aneuploidija (36,5±0,74; 60,25±0,24; 85,62±0,5) i poliploidija (70,24; 5,5±0,21; 5,87±0,14) što ukazuje na postojanje genotoksičnog potencijala ispitivane supstance

Novel insights regarding the role of noncoding RNAs in diabetes

Diabetes mellitus (DM) is a group of metabolic disorders defined by hyperglycemia induced by insulin resistance, inadequate insulin secretion, or excessive glucagon secretion. In 2021, the global prevalence of diabetes is anticipated to be 10.7% (537 million people). Noncoding RNAs (ncRNAs) appear to have an important role in the initiation and progression of DM, according to a growing body of research. The two major groups of ncRNAs implicated in diabetic disorders are miRNAs and long noncoding RNAs. miRNAs are singlestranded, short (17–25 nucleotides), ncRNAs that influence gene expression at the post-transcriptional level. Because DM has reached epidemic proportions worldwide, it appears that novel diagnostic and therapeutic strategies are required to identify and treat complications associated with these diseases efficiently. miRNAs are gaining attention as biomarkers for DM diagnosis and potential treatment due to their function in maintaining physiological homeostasis via gene expression regulation. In this review, we address the issue of the gradually expanding global prevalence of DM by presenting a complete and upto-date synopsis of various regulatory miRNAs involved in these disorders. We hope this review will spark discussion about ncRNAs as prognostic biomarkers and therapeutic tools for DM. We examine and synthesize recent research that used novel, high-throughput technologies to uncover ncRNAs involved in DM, necessitating a systematic approach to examining and summarizing their roles and possible diagnostic and therapeutic uses

Analiza DNK oštećenja izazvanog tiazofurinom u humanim ćelijama pune krvi primenom in vitro komet testa

Objective. Inosine 5’-monophosphate dehydrogenase (IMPDH) activity in cancer cells is increased. Tiazofurin selectively inhibits the activity of IMPDH, and it has been granted for the treatment of different cancers and new viral diseases. Its widespread use was limited because exposure to tiazofurin under certain circumstances was found to have a higher frequency of severe non-hematologic toxicity. Therefore, the objective of this study was to examine genotoxic action and inducement of DNA damage of tiazofurin using the comet assay. Methods. The ability of tiazofurin to induce DNA damage was evaluated using single-cell gel electrophoresis (SCGE) technique/comet assay. Human whole blood cells were exposed to three final concentrations of tiazofurin (1 µM/mL, 2 µM/mL, and 5 µM/mL) for 30 min in vitro. Results. Our results indicate that tiazofurin produced a significant level of DNA damage on whole blood cells after 30 min of exposure vs. control. All tested concentrations were significantly comet-forming, in a concentration-dependent manner. Conclusion. Our investigation on the tiazofurin-treated cells and their relationship to the formation of DNA damage demonstrated that the genotoxic effect was induced after exposure to tiazofurin under described conditions.Cilj. Aktivnost inozin 5'-monofosfat dehidrogenaze (IMPDH) povec'ana je u c'elijama karcinoma. Tiazofurin selektivno inhibira aktivnost IMPDH i odobren je za lečenje različitih karcinoma i novih virusnih bolesti. Njegova široko rasprostranjena upotreba bila je ograničena jer je utvrđeno da je izloženost tiazofurinu pod određenim okolnostima imala vec'u incidencu ozbiljne nehematološke toksičnosti. Stoga je cilj ove studije bio da se pomoc'u komet testa ispita genotoksično delovanje i izazivanje DNK oštec'enja tiazofurinom. Metode. Sposobnost tiazofurina da izazove DNK oštec'enje procenjena je primenom elektroforeze DNK pojedinačnih ćelija (SCGE) / komet testa. Ćelije pune krvi su bile izložene trima konačnim koncentracijama tiazofurina (1 µM/mL, 2 µM/mL, and 5 µM/mL) tokom 30 minuta in vitro. Rezultati. Naši rezultati ukazuju na to da je tiazofurin proizveo značajan nivo DNK oštec'enja na c'elijama pune krvi nakon 30 minuta izlaganja u odnosu na kontrolu. Sve ispitivane koncentracije su dovele do značajnog nastanka kometa, pri čemu je nivo oštećenja rastao s koncentracijom. Zaključak. Naše istraživanje c'elija tretiranih tiazofurinom i njihova reakcija na izazivanje DNK oštec'enja pokazalo je da je tiazofurin ispoljio genotoksični efekat pod opisanim uslovima

Antigenotoxic Effects of Biochaga and Dihydroquercetin (Taxifolin) on H2O2-Induced DNA Damage in Human Whole Blood Cells

The health benefits of natural products have long been recognized. Consumption of dietary compounds such as supplements provides an alternative source of natural products to those obtained from the diet. There is a growing concern regarding the possible side effects of using different food supplements simultaneously, since their possible interactions are less known. For the first time, we have tested genotoxic and antigenotoxic effects of Biochaga, in combination with dihydroquercetin. No genotoxic effect on whole blood cells was observed within individual treatment of Biochaga (250 μg/mL, 500 μg/mL and 1000 μg/mL) and dihydroquercetin (100 μg/mL, 250 μg/mL and 500 μg/mL), nor in combination. Afterwards, antigenotoxic potency of both supplements against hydrogen peroxide- (H2O2-) induced DNA damage to whole blood cells (WBC) was assessed, using the comet assay. Biochaga and dihydroquercetin displayed a strong potential to attenuate H2O2-induced damage on DNA in cells at all tested concentrations, with a statistical significance (p < 0:05), whereas Biochaga at the dose of 500 μg/mL in combination with dihydroquercetin 500 μg/mL was most prominent. Biochaga in combination with dihydroquercetin is able to protect genomic material from oxidative damage induced by hydrogen peroxide in vitro

Cytogenetic alterations in peripheral cells of Alzheimer’s disease patients

Alzheimer’s disease (AD) is the most frequent progressive neurodegenerative disorder in elderly associated with irreversible cognitive impairment and dementia. The vast majority of AD patients are sporadic (SAD) in which the disease develops after age of 65. Despite of century of research, we lack understanding of the SAD etiology and pathogenesis. Several hypotheses try to explain the main causes of brain degeneration in SAD, one of them assuming that genomic instability and the reentry of certain neurons into the incomplete cell cycle may be the pathogenic basis of the disease. Although the brain is the most affected organ in AD, numerous studies showed structural and functional alterations in peripheral tissues, suggesting that AD is a generalized systemic disorder. Diverse changes in peripheral cells from AD patients are described in literature including cell cycle aberration and chromosome instability, alterations in cell viability, proliferation and apoptosis, oxidative metabolism, amyloid precursor protein and amyloid β protein metabolism, and other cellular processes. The aim of this paper was to summarize and review the results of our investigations and the growing literature data concerning the multiple chromosomal alterations in peripheral cells of AD patients and to consider their possible role in the disease pathogenesis as well as the importance of such investigations. [Projekat Ministarstva nauke Republike Srbije, br. 173034

Examination of the effects of X-ray phase contrast imaging dose on DNA in mesenchymal stem cells by comet assay

INTRODUCTION: Imaging techniques based on X-ray phase-contrast (XPC) have shown tremendous promise for applications involving biomaterials and soft tissue formation [1,2].XPC imaging can be applied at higher energy offering the potential for lower dose imaging. Essential to the development of this technique and its routine use is an understanding of the potential damage of X-ray dose on cells and tissues. EXPERIMENTAL: In this study the comet assay, a sensitive assay for DNA damage, was used to evaluate DNA damage on mesenchymal stem cells (MSCs) exposedto X-ray irradiation. We examined the effects of early (immediately following irradiation) and delayed (24h post-irradiation) X-ray effects caused by low (15mGy) and intermediate (150mGy and 1.5 Gy) exposure on MSCs during a monitoring period of 4 weeks (five irradiations, one weekly). Cells were submitted to apolychromatic X-ray source (Thermo Fisher PXS10 conditions: voltage 45 kV, source current 160A, source power 7.2 W, source spot size 9 um, photon flux on the sample 7.66106photonss-1mm-2irradiation).Statistical analysis was performedby using Two-way analysis of variance (ANOVA) with Tukey’s multiple comparisons posttest in GraphPad Prism 5.0.A difference at p< 0.05 was considered statistically significant.RESULTS AND DISCUSSION: Resultsof the DNA comet assay indicated that early effects of low-and intermediate-dose of XPC induced an increase in the number of cells with DNA damage after each irradiation, where intermediate-dose (150 mGy and 1.5 Gy) produced significantly higher damage relative to controls. DNA damage induced by low and intermediate doses returned to the control value 24h after the irradiation exposure, suggesting a strong protection of MSCs at the tested doses of XPC irradiation. CONCLUSIONS: The data presented in this studyshows that 24 h after the last of five weekly low and intermediate doses XPC irradiation, the harmful effects on DNA in MSCs were notdetected. The current study reinforces the need of investigating consequences of low and intermediate doses of X-ray PC irradiation in the field of tissue engineering and provide new basis for MSCs using in the clinics.ExcellMater Conference 2024: Innovative Biomaterials for Novel Medical Devices, Belgrade, Serbia, April 10-12, 2024

Assessment of adrenaline-induced DNA damage in whole blood cells with the comet assay

Harmful effects of elevated levels of catecholamines are mediated by various mechanisms, including gene transcription and formation of oxidation products. The aim of this study was to see whether the molecular mechanisms underlying the damaging action of adrenaline on DNA are mediated by reactive oxygen species (ROS). To do that, we exposed human whole blood cells to 10 mu mol L-1 adrenaline or 50 mu mol L-1 H2O2 (used as positive control) that were separately pre-treated or post-treated with 500 mu mol L-1 of quercetin, a scavenger of free radicals. Quercetin significantly reduced DNA damage in both pre- and post-treatment protocols, which suggests that adrenaline mainly acts via the production of ROS. This mechanism is also supported by gradual lowering of adrenaline and H2O2-induced DNA damage 15, 30, 45, and 60 min after treatment. Our results clearly show that DNA repair mechanisms are rather effective against ROS-mediated DNA damage induced by adrenaline

The X Files: “The Mystery of X Chromosome Instability in Alzheimer’s Disease”

Alzheimer’s disease (AD) is a neurodegenerative disease that affects millions of individuals worldwide and can occur relatively early or later in life. It is well known that genetic components, such as the amyloid precursor protein gene on chromosome 21, are fundamental in early-onset AD (EOAD). To date, however, only the apolipoprotein E4 (ApoE4) gene has been proved to be a genetic risk factor for late-onset AD (LOAD). In recent years, despite the hypothesis that many additional unidentified genes are likely to play a role in AD development, it is surprising that additional gene polymorphisms associated with LOAD have failed to come to light. In this review, we examine the role of X chromosome epigenetics and, based upon GWAS studies, the PCDHX11 gene. Furthermore, we explore other genetic risk factors of AD that involve X-chromosome epigenetics

Chromosome instability in Alzheimer's disease

Alzheimer's disease (AD), as the most common form of dementia, has for many years attracted the attention of researchers around the world, primarily because of the problems of reliable diagnostic methods that could help in the early detection of this devastating disease. One of the important aspects of genetic research related to AD is the analysis of chromosome instability which includes: aneuploidies of different chromosomes, telomere shortening and the phenomenon of premature centromere division (PCD). The aim of this study was to describe specific biomarkers in different types of cells as potential parameters for the diagnosis of AD in order to promptly recognize pre-symptomatic stages and prevent the development of disease and/or slow down its progression

Evaluation of the antioxidant potential of Biochaga in vitro

Background: Antioxidants and prooxidants have an impact on the intracellular oxidative equilibrium. Overproduction of prooxidants leads to oxidative stress caused by imbalances in oxidative reduction pathways. The body can be supplied with non-enzymatic, low molecular weight antioxidants through diet.The edible medicinal mushroom Chaga, Inonotus obliquus (Ach. ex Pers.) Pilat, has long been long used to treat or prevent various health conditions and disorders. The bioactive compounds of Chaga exhibit antitumor, anti-inflammatory, hypoglycemic, immunomodulatory, antioxidant, and antigenotoxic effects. Material and Methods: DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging activity, FRAP (ferric reducing antioxidant power) total antioxidant activity, and hydroxyl radical scavenging capacity were measured. Results: Commercial Biochaga (B), a water extract of Biochaga mushroom, was obtained from Sibpribor Ooo, Irkutsk, Russia. B (IC =5.9 mg/ mL) showed moderate reducing power compared in comparison to vitamin C and strong compared to BTH. B (IC =1.78 mg/mL) showed remarkable free radical scavenging and moderate hydroxyl scavenging activity (IC =8.473 mg/mL). Conclusion: We can place Biochaga in the radical scavenging category because it efficiently eliminates hydroxyl radicals against which the body has insufficient antioxidant defenses.14th Balkan Congress of Human Genetics and 9 th Rare Disease SEE Meeting “Genetic Diseases from Diagnostics to Prevention and Therapy”(ABSTRACT BOOK), October 05-07, 2023, Hotel “DoubleTree by Hilton” Skopje, North Macedoni