Molecular and immunological changes in blood of rats exposed to various doses of asbestos dust.

BACKGROUND: Asbestos-related diseases are a group of diseases resulting from the inhalation of asbestos fibres and their subsequent deposition in the lung parenchyma, which causes the development of inflammatory and fibrotic processes in the respiratory system. Cases of the disease often occur in the practice of doctors. AIMS: The purpose of the study was to examine the level of circulating-free mitochondrial DNA (cf mtDNA), pro-inflammatory cytokines, immunological status and structural changes in the lung of rats exposed to various doses of asbestos dust. METHODS: Immune monitoring was performed using the peripheral blood samples of 40 male Wistar rats exposed and unexposed to asbestos dust. cf mtDNA copy numbers were detected using quantitative real-time polymerase chain reaction (qRT-PCR) and cytokines were determined using a rat Enzyme Linked Immuno Sorbent Assay (ELISA) kit. RESULTS: A comprehensive assessment of the histopathological study performed under exposure to asbestos at a dose of 25 mg and 50 mg showed the presence of pronounced structural defects in the lung tissue of laboratory rats. The level of cf mtDNA in plasma of rats exposed to asbestos at a dose of 25 mg was reliably higher than that of control rats, and animals exposed to asbestos at a dose of 50 mg. The highest levels of pro-inflammatory cytokines IL-6 and TNF-a were also observed after asbestos dusting at a dose of 25 mg. CONCLUSIONS: According to the results of the immunological status obtained, the decrease in the levels of pro-inflammatory cytokines in the blood plasma at 50 mg is due to the immunosuppressive effect in the rat immune system at this dose. A positive correlation was found between TNF-a level and copy numbers of cf mtDNA at a dose of 25 mg.

The Plasma Levels of hsa-miR-19b-3p, hsa-miR-125b-5p, and hsamiR- 320c in Patients with Asthma, COPD and Asthma-COPD Overlap Syndrome (ACOS).

BACKGROUND: Bronchial Asthma (BA) and Chronic Obstructive Pulmonary Disease (COPD) are chronic airway inflammation diseases. In recent years, patients with signs of both BA and COPD have been assigned to a separate group as Asthma-COPD Overlap Syndrome (ACOS). Free-circulating plasma microRNAs are considered as potential biomarkers of pulmonology diseases, including BA, COPD, and ACOS. OBJECTIVE: This study aimed to investigate the expression level of free-circulating plasma microRNAs, hsa-miR-19b-3p, hsa-miR-125b-5p, and hsa-miR-320c in patients with BA, COPD and ACOS for the detection and validation of new microRNAs as biomarkers for chronic lung diseases. METHODS: The relative expression levels of 720 microRNAs were evaluated by Real Time-Polymerase Chain Reaction (RT-PCR) in patients with COPD and BA. Three upregulated microRNAs (hsa-miR-19b-3p, hsa-miR-125b-5p and hsa-miR-320c) were selected for further study. The obtained data were analyzed using the microRNA PCR Array Data Analysis tool. The sensitivity and specificity were estimated using the area under the Receiver Operating Characteristics curve (ROC). RESULTS: The expression level of free-circulating hsa-miR-19b-3p was decreased in the blood plasma of patients with BA and ACOS, and increased in patients with COPD. hsa-miR-125b-5p was downregulated in the blood plasma of patients with COPD and upregulated in patients with BA and ACOS. hsa-miR-320c was downregulated in the blood plasma of patients with BA, and upregulated in patients with COPD and ACOS. The ROC curves of patients with BA for hsa-miR-19b-3p, patients with ACOS for hsa-miR-125b-5p, and patients with COPD for hsa-miR-320c revealed the probability of them as valuable biomarkers with AUCs of 0.824, 0.825, and 0.855, respectively. CONCLUSION: Our study revealed three promising biomarkers for the diagnosis of COPD, BA and ACOS.

Role of microRNAs in Lung Carcinogenesis Induced by Asbestos.

MicroRNAs are a class of small noncoding endogenous RNAs 19-25 nucleotides long, which play an important role in the post-transcriptional regulation of gene expression by targeting mRNA targets with subsequent repression of translation. MicroRNAs are involved in the pathogenesis of numerous diseases, including cancer. Lung cancer is the leading cause of cancer death in the world. Lung cancer is usually associated with tobacco smoking. However, about 25% of lung cancer cases occur in people who have never smoked. According to the International Agency for Research on Cancer, asbestos has been classified as one of the cancerogenic factors for lung cancer. The mechanism of malignant transformation under the influence of asbestos is associated with the genotoxic effect of reactive oxygen species, which initiate the processes of DNA damage in the cell. However, epigenetic mechanisms such as changes in the microRNA expression profile may also be implicated in the pathogenesis of asbestos-induced lung cancer. Numerous studies have shown that microRNAs can serve as a biomarker of the effects of various adverse environmental factors on the human body. This review examines the role of microRNAs, the expression profile of which changes upon exposure to asbestos, in key processes of carcinogenesis, such as proliferation, cell survival, metastasis, neo-angiogenesis, and immune response avoidance.

The Potential Role of miRNA-19b-3p and miRNA-320c in Patients with Moderate Bronchial Asthma.

BACKGROUND: Bronchial Asthma (BA) is a complex heterogeneous disease with a number of molecular immunopathological mechanisms underlying airway inflammation, hyperreactivity, and bronchial remodeling. MicroRNAs are important regulators in the pathogenesis and progression of chronic respiratory diseases, including BA. OBJECTIVE: The aim of the study is to investigate the level of expression of cell-free circulating miR-19b-3p and miR-320c in the blood plasma by comparing their plasma levels with IL-4 in the moderate BA patients and control group. METHODS: The level of expression miR-19b-3p and miR-320c were evaluated by qRT-PCR using the comparative threshold cycle (Ct) method. U6 small nuclear RNA was taken as an endogenous control. The content of IL - 4 in blood plasma was determined by using ELISA. RESULTS: miR-19b-3p and miR-320c were significantly dysregulated in moderate asthmatic patients in comparison with control group. The area under the ROC curve of miR-19b-3p and miR-320c showed 0.8088 (95% CI 0.6925 to 0.9251, P value =0.0001) and 0,9048 (95% CI 0,7792 to 1,000, P value <0,0001), respectively. BA patients showed a considerably positive correlation between the expression level of microRNA-320c and IL-4 levels. CONCLUSION: These cell-free circulating microRNAs are probably deregulated in other inflammatory/ pathological diseases, so they could be useful to understand the molecular pathogenesis of BA or to investigate the "inflammatory reaction" in this disease.

Formation of mammalian preribosomes proceeds from intermediate to composed state during ribosome maturation.

In eukaryotes, ribosome assembly is a rate-limiting step in ribosomal biogenesis that takes place in a distinctive subnuclear organelle, the nucleolus. How ribosomes get assembled at the nucleolar site by forming initial preribosomal complexes remains poorly characterized. In this study, using several human and murine cell lines, we developed a method for isolation of native mammalian preribosomal complexes by lysing cell nuclei through mild sonication. A sucrose gradient fractionation of the nuclear lysate resolved several ribonucleoprotein (RNP) complexes containing rRNAs and ribosomal proteins. Characterization of the RNP complexes with MS-based protein identification and Northern blotting-based rRNA detection approaches identified two types of preribosomes we named here as intermediate preribosomes (IPRibs) and composed preribosome (CPRib). IPRib complexes comprised large preribosomes (105S to 125S in size) containing the rRNA modification factors and premature rRNAs. We further observed that a distinctive CPRib complex consists of an 85S preribosome assembled with mature rRNAs and a ribosomal biogenesis factor, Ly1 antibody-reactive (LYAR), that does not associate with premature rRNAs and rRNA modification factors. rRNA-labeling experiments uncovered that IPRib assembly precedes CPRib complex formation. We also found that formation of the preribosomal complexes is nutrient-dependent because the abundances of IPRib and CPRib decreased substantially when cells were either deprived of amino acids or exposed to an mTOR kinase inhibitor. These findings indicate that preribosomes form via dynamic and nutrient-dependent processing events and progress from an intermediate to a composed state during ribosome maturation.

EPHX1 Y113H polymorphism is associated with increased risk of chronic obstructive pulmonary disease in Kazakhstan population.

Chronic obstructive pulmonary disease (COPD) is a type of obstructive lung disease characterized by long term poor airflow which worsens over time. It is considered to be one of the top five chronic diseases of the world in terms of morbidity and mortality. Genetic variability has been found to contribute to the development of COPD. Although association between gene polymorphisms in EPHX1 and TNF-a genes and chronic obstructive pulmonary disease (COPD) have been found but till date no genetic association studies have been done in the COPD affected Kazakhstan population. The aim of the present work was to investigate the association between the Y113H polymorphism (rs1051740) in EPHX1 gene and -308G/A polymorphism (rs1800629) in TNF-a gene and COPD in Kazakhstan population. A case-control study was conducted in Astana and Akmola regions of Kazakhstan, involving 55 cases with COPD and 52 healthy individuals who served as the controls. The polymorphisms were determined using conventional PCR and Sanger sequencing method. Results show that for the EPHX1 gene Y113H polymorphism, the presence of an "C" allele (TC/CC genotype) was significantly overrepresented in the COPD patients compared to the controls. For the TNF-a gene -308G/A polymorphism, no significant difference was found between the two groups. Thus we found that, Y113H polymorphism in EPHX1 gene contributed to increased susceptibility to COPD in the Kazakhstan population.