Molecular Biology最新文献

Abstract—Spore-forming bacteria have a unique resistance to negative environmental conditions, including aggressive space factors, and are an excellent model for studying adaptation mechanisms and survival strategies at the molecular level. The study analyzed the genome of Bacillus velezensis, which remained viable after a 2-year exposure in outer space on the outer surface of the ISS as part of the Test space experiment. A comparative analysis of the draft genomes of the exhibit strain and the ground control did not reveal significant changes; the average nucleotide identity was 99.98%, which indicates the ability of microorganisms to maintain genome stability in space conditions, due to both increased stress resistance of bacterial spores and efficient operation of the system of repair of accumulated changes. The study of a single nucleotide polymorphism in the genome of B. velezensis revealed nine point substitutions, three of which are in intergenic regions, six in protein-coding genes, three of them are missense mutations, two nucleotide deletions leading to a shift in the reading frame, and one synonymous substitution. The profiles of the housekeeping genes were determined during MLST typing and it was found that the allelic profiles obtained for B. velezensis T15.2 and 924 strains do not correspond to any of the previously described sequence types.The presented results indicate the ability of B. velezensis bacteria to maintain the viability of spores and the integrity of the genome for a long time under extreme conditions of outer space, which is important for the problem of planetary protection, as well as the potential possibility of performing biotechnological processes based on B. velezensis during space exploration.

Abstract—CRISPR/Cas systems are perspective molecular tools for targeted manipulation with genetic materials, such as gene editing, regulation of gene transcription, modification of epigenome etc. While CRISPR/Cas systems proved to be highly effective for correcting genetic disorders and treating infectious diseases and cancers in experimental settings, clinical translation of these results is hampered by the lack of efficient CRISPR/Cas delivery vehicles. Modern synthetic nanovehicles based on organic and inorganic polymers have many disadvantages, including toxicity issues, the lack of targeted delivery, and complex and expensive production pipelines. In turn, exosomes are secreted biological nanoparticles that exhibit high biocompatibility, physico-chemical stability, and the ability to cross biological barriers. Early clinical trials found no toxicity associated with exosome injections. In the recent years, exosomes have been considered as perspective delivery vehicles for CRISPR/Cas systems in vivo. The aim of this study was to analyze the efficacy of CRISPR/Cas stochastic packaging into exosomes for several human cell lines. Here, we show that Cas9 protein is effectively localized into the compartment of intracellular exosome biogenesis, but stochastic packaging of Cas9 into exosomes turns to be very low (~1%). As such, stochastic packaging of Cas9 protein is very ineffective and cannot be used for gene editing purposes. Developing novel tools and technologies for loading CRISPR/Cas systems into exosomes is needed.

Abstract

KNOTTED-LIKE HOMEOBOX (KNOX) proteins are homeodomain containing transcription factors, and regulate many aspects of plant development through homo or heterodimerization with another group of TALE transcription factors known as BELL. In Medicago truncatula the MtKNOX3 gene is involved in nodule development. In this work, we hypothesized that MtKNOX3 involvement in the activation of cytokinin signaling during nodule development could be through heterodimerization with BELL proteins. Thereby, the expression of different BELL genes in Medicago was analyzed, and it was shown that the expression of Medtr8g078480 and Medtr8g098815 genes increases during nodule development. Besides, the Medtr8g078480 shows a co-expression pattern with MtKNOX3 at different developmental stages of nodule development. Afterward, the interaction of MtKNOX3 with the MtBELL1-2 (Medtr8g078480) protein was shown using docking, and their stability was analyzed by molecular dynamic simulation and mmpbsa methods. Moreover, the stability of MtKNOX3- Medtr8g078480 heterodimers was compared with the MtKNOX3 homodimer.

Abstract—Ischemia–reperfusion is a cascade of complex and interrelated pathological processes underlying many human diseases, including such socially significant diseases as stroke, myocardial infarction, acute renal failure, etc. The present review considers modern ideas about the main biochemical and signal-regulatory processes in the cell under conditions of ischemia–reperfusion. Both generally accepted and newly developed ways of ischemia–reperfusion lesion correction aimed at different chains of this pathological process are considered.

Abstract

Peripheral blood biomarkers are of particular importance to diagnose certain diseases including coronary artery disease (CAD) due to their non-invasiveness. Investigating the expression of noncoding RNAs (ncRNAs) paves the way to early disease diagnosis, prognosis, and treatment. Consequently, in this research, we aimed to investigate a panel of ncRNAs as potential biomarkers in patients with coronary artery disease. Two different groups have been designed (control and CAD). All participants were subjected to interviews and clinical examinations. Peripheral blood samples were collected, and plasma was extracted. At the same time, target ncRNAs have been selected based on literature review and bioinformatic analysis, and later they underwent investigation using quantitative real-time PCR. The selected panel encompassed the long non-coding RNAs (lncRNAs) MEG3, TUG1, and SRA1, and one related microRNA (miRNA): hsa-miR-21-3p. We observed statistically significant upregulation in MEG3, TUG1, and hsa-miR21-3p in CAD patients compared to control participants (p-value < 0.01). Nevertheless, SRA1 exhibited downregulation with no statistical significance (p-value > 0.05). All ncRNAs under study displayed a significantly strong correlation with disease incidence, age, and smoking. Network construction revealed a strong relationship between MEG3 and TUG1. ROC analysis indicated high potentiality for hsa-miR-21-3p to be a promising biomarker for CAD. Moreover, MEG3 and TUG1 displayed distinguished diagnostic discrimination but less than hsa-miR-21-3p, all of them exhibited strong statistical significance differences between CAD and control groups. Conclusively, this research pinpointed that MEG3, TUG1, and hsa-miR-21-3p are potential biomarkers of CAD incidence and diagnosis.

Abstract

Protein repeats are a source of rapid evolutionary and functional novelty. Repeats are crucial in development, neurogenesis, immunity, and disease. Repeat length variability and purity can alter the outcome of a pathway by altering the protein structure and affecting the protein−protein interaction affinity. Such rampant alterations can facilitate species to rapidly adapt to new environments or acquire various morphological/physiological features. With more than 11000 species, the avian clade is one of the most speciose vertebrate clades, with near-ubiquitous distribution globally. Explosive adaptive radiation and functional diversification facilitated the birds to occupy various habitats. High diversity in morphology, physiology, flight pattern, behavior, coloration, and life histories make birds ideal for studying protein repeats’ role in evolutionary novelty. Our results demonstrate a similar repeat diversity and proportion of repeats across all the avian orders considered, implying an essential role of repeats in necessary pathways. We detected positively selected sites (PSS) in the polyQ repeat of RUNX2 in the avian clade; and considerable repeat length contraction in the Psittacopasserae. The repeats show a species-wide bias towards a contraction in Galloanseriformes. Interestingly, we detected the length contrast of polyS repeat in PCDH20 between Galliformes and Anseriformes. We speculate the length variability of serine repeat and its interaction with β-catenin in the Wnt/β-catenin signaling pathway could have facilitated fowls to adapt to their respective environmental conditions. We believe our study emphasizes the role of protein repeats in functional/morphological diversification in birds. We also provide an extensive list of genes with considerable repeat length contrast to further explore the role of length volatility in evolutionary novelty and rapid functional diversification.

Abstract

Temozolomide resistance is a major cause of recurrence and poor prognosis in neuroglioma. Recently, growing evidence has suggested that mitophagy is involved in drug resistance in various tumor types. However, the role and molecular mechanisms of mitophagy in temozolomide resistance in glioma remain unclear. In this study, mitophagy levels in temozolomide-resistant and -sensitive cell lines were evaluated. The mechanisms underlying the regulation of mitophagy were explored through RNA sequencing, and the roles of differentially expressed genes in mitophagy and temozolomide resistance were investigated. We found that mitophagy promotes temozolomide resistance in glioma. Specifically, small ubiquitin-like modifier specific protease 6 (SENP6) promoted temozolomide resistance in glioma by inducing mitophagy. Protein-protein interactions between SENP6 and the mitophagy executive protein PTEN-induced kinase 1 (PINK1) resulted in a reduction in small ubiquitin-like modifier 2 (SUMO2)ylation of PINK1, thereby enhancing mitophagy. Our study demonstrates that by inducing mitophagy, the interaction of SENP6 with PINK1 promotes temozolomide resistance in glioblastoma. Therefore, targeting SENP6 or directly regulating mitophagy could be a potential and novel therapeutic target for reversing temozolomide resistance in glioma.

Abstract—Hsp70 and hydrogen sulfide donors reduce inflammatory processes in human and animal cells. The biological action mediated by Hsp70 and H₂S donors (GYY4137 and sodium thiosulfate) depends on their protection kinetics from cell activation by lipopolysaccharides. However, the molecular mechanisms of action of Hsp70 and H₂S are not well understood. We studied the effect of human recombinant Hsp70 and H₂S donors on the formation of reactive oxygen species and tumor necrosis factor-alpha induced in human cells (THP-1) by lipopolysaccharides. Transcriptomic changes occurring in these cells after LPS administration in combination with GYY4137 pretreatment were investigated. The results we obtained showed that Hsp70 and hydrogen sulfide donors reduce inflammatory processes in cells activated by the action of LPS. Hsp70 and H₂S donors differed in the kinetics of the protective action, while hydrogen sulfide donors turned out to be more effective. The role of endocytosis in the mechanisms of protection of cells by H₂S and Hsp70 donors from the action of LPS was studied. It has been found that GYY4137 pretreatment of LPS-exposed cells reduces the LPS-induced induction of various pro-inflammatory genes and affects the expression of genes of various intracellular signaling pathways.