The Transcriptome-Wide N6-Methyladenosine (m6A) Map Profiling Reveals the Regulatory Role of m6A in the Yak Ovary

Background and aim: Yak estrus is a seasonal phenomenon, probably involving epigenetic regulation of synthesis and secretion of sex hormones as well as growth and development of follicles. N6-methyladenosine (m6A) is the most common internal modification of the eukaryotic mRNA. However, there are no detailed reports on the m6A transcriptome map of yak ovary. Therefore, this study aimed to collected the yak ovarian tissues at three different states of anestrus (YO-A), estrus (YO-F), and pregnancy (YO-P), and obtained the full transcriptome m6A map in yak by MeRIP-seq. Results: The HE staining revealed that the number of growing follicles and mature follicles in the ovary during the estrus period was relatively higher than those in the estrus period and the pregnancy period. The RT-qPCR showed that the expression of METTL3, METTL14, FTO, YTHDC1 were significantly different across different periods in the ovaries, which suggests that m6A may play a regulatory role in ovarian activity. Next, we identified 20174, 19747 and 13523 m6A peaks in the three ovarian samples of YO-A, YO-F and YO-P using the methylated RNA immunoprecipitation sequencing (MeRIP-seq). The m6A peaks are highly enriched in the coding sequence (CDS) region and 3′untranslated region (3′UTR) as well as the conserved sequence of “RRACH.” Functional analysis revealed the involvement of m6A in many physiological activities of the yak’s ovary during reproductive cycle. The association analysis found that some genes such as BNC1, HOMER1, BMP15, BMP6, GPX3, and WNT11 were related to ovarian functions. Conclusions: The comparison of the distribution patterns of methylation peaks in the ovarian tissues across different periods further explored the m6A markers related to the regulation of ovarian ovulation and follicular development in the yak ovary. This comprehensive map provides a solid foundation for revealing the potential function of the mRNA m6A modification in the yak ovary.

Hereditary antithrombin deficiency in pregnancy – severe thrombophilic disorder as a danger for mother and foetus

Summary Setting: In the article, we remember the role of antithrombin (AT) in hemostasis, escalation of AT-potential with heparin and difficulties with monitoring the effectiveness of LMWH therapy (low molecular weight heparin) in patients with AT deficiency. We pay most of our attention to hereditary AT deficiency and its thromboembolic risk in pregnancy. Methods: In the introduction, the principle of AT function, its two main domains and the regulation of synthesis are cleared. We describe the causal mutations of hereditary AT deficiency in SERPINC1 gen and the relation to a thromboembolic risk. The general recommendations for patients with hereditary AT deficiency and pregnant women are mentioned. As the risk of thromboembolic disease is escalated in pregnancy, the LMWH should always be considered. There has been frequently observed that patients with AT deficiency do not elevate anti-Xa-levels when standard prophylactic LMWH doses are used. This fact well illustrates that heparin without AT may not inhibit the active coagulant factors efficiently enough. Therefore, if a high thromboembolic risk in the patient’s anamnesis is present, the LMWH dosing should be escalated. In individual cases, concomitant administration of an antithrombin concentrate to the heparin treatment is recommended at the time of delivery or in the case of deep venous thrombosis. In this article, three cases of unusual pregnancy in patients with different types of AT deficiency are reported. The case reports are summarized from the Department of Hematology at Hospital Kolín, the Centre of Hemostasis and Thrombosis at Institute of Hematology and Blood Transfusion in Prague and from cooperating obstetrical departments in the Czech Republic. Results: We demonstrated the threat of hereditary AT deficiency in three case reports. In one case, the estimated risk of thromboembolism – type I of AT-deficiency (quantitative) – was in a good correlation with real peripartal complications. In the next two cases with different types of AT deficiency, we showed surprising courses of complicated pregnancies. Conclusion: As it has been shown, it is not safe to estimate the risk of thromboembolism on the base of causal mutation for AT deficiency. For present clinical practice, we should still remember AT deficiency as a potentially very dangerous thromboembolic disorder for mother and fetus; thus, excellent cooperation of an obstetrician and a hematologist is necessary.

In-silico analysis of mutations in ANK1, SPTB, SPTA1, SLC4A1, and EPB4.2 genes responsible for Hereditary Spherocytosis

Hereditary spherocytosis (HS) is a rare inherited disorder of red blood cells which are characterized by spherical, doughnut-shaped with increase deformability that lead to the gallstones and splenomegaly. The role of mutation in the genes responsible for the regulation of synthesis of proteins and stucture of RBC is well know studied. It was found that there are five genes whose mutation result in hereditary spherocytosis.Therefore, we aimed to study the consequences of ANK1, EPB4.2, SPTA1, SPTB, and SLC4A1 non-synonymous mutaion by using advanced inslico methods. Studied for nsSNPs using insilico techniques including OMIN, clinVar, SIFT, Polyphen, homology modelling. Misssence nsSNP were identified in all the gene selected and their effect on the protein structure, stability and functioning was studies. The result showed that 52 nsSNPs are responsible for the changes in the shape of RBCs. After identifying the nsSNPs the structure of proteins were modelled and their RMSD, relative solvent accessibility, and protein stability were studied. Protein stability analysis revealed significant change in free energy (ΔΔG) of the most identified nsSNPs variants. These finding may be helpful for genotype-phenotype research as well as development in pharmacogenetic studies. Finally, this study unveil a significance of inslico methods to figure out highly pathogenic genomic variants affected the structure and functional of HS causing protein

Mucus barrier, mucins and gut microbiota: the expected slimy partners?

The gastrointestinal tract is often considered as a key organ involved in the digestion of food and providing nutrients to the body for proper maintenance. However, this system is composed of organs that are extremely complex. Among the different parts, the intestine is viewed as an incredible surface of contact with the environment and is colonised by hundreds of trillions of gut microbes. The role of the gut barrier has been studied for decades, but the exact mechanisms involved in the protection of the gut barrier are various and complementary. Among them, the integrity of the mucus barrier is one of the first lines of protection of the gastrointestinal tract. In the past, this ‘slimy’ partner was mostly considered a simple lubricant for facilitating the progression of the food bolus and the stools in the gut. Since then, different researchers have made important progress, and currently, the regulation of this mucus barrier is gaining increasing attention from the scientific community. Among the factors influencing the mucus barrier, the microbiome plays a major role in driving mucus changes. Additionally, our dietary habits (ie, high-fat diet, low-fibre/high-fibre diet, food additives, pre- probiotics) influence the mucus at different levels. Given that the mucus layer has been linked with the appearance of diseases, proper knowledge is highly warranted. Here, we debate different aspects of the mucus layer by focusing on its chemical composition, regulation of synthesis and degradation by the microbiota as well as some characteristics of the mucus layer in both physiological and pathological situations.

iscovery of Nuclear DNA-like RNA (dRNA, hnRNA) and Ribonucleoproteins Particles Containing hnRNA

On August 9-11, 2014, Cold Spring Harbor (USA) hosted a special symposium dedicated to the discovery of messenger or informational RNA and the main events in the subsequent studies of its synthesis, regulation of synthesis, maturation, and transport. The existence of mRNA in bacteria was first suggested in 1961 by Jacob and Monod, based on genetic studies [1]. The same year, Brenner et al. confirmed the hypothesis [2]. Our laboratory played a key role in the discovery of messenger RNA in eukaryotes, as well as in the discovery of the nuclear ribonucleoproteins that contain it and in the elucidation of their structural organization. Therefore, I was invited to represent Russia at the Symposium and deliver a speech on these topics. However, my visa had only been issued after the end of the Symposium, and, therefore, the presentation was delivered by my former colleague G.N. Yenikolopov, who works at Cold Spring Harbor Laboratory. The transcript of the lecture is presented below.

Regulation of Synthesis and Roles of Hyaluronan in Peritoneal Dialysis

Hyaluronan (HA) is a ubiquitous extracellular matrix glycosaminoglycan composed of repeated disaccharide units of alternating D-glucuronic acid and D-N-acetylglucosamine residues linked via alternatingβ-1,4 andβ-1,3 glycosidic bonds. HA is synthesized in humans by HA synthase (HAS) enzymes 1, 2, and 3, which are encoded by the correspondingHASgenes. Previous in vitro studies have shown characteristic changes in HAS expression and increased HA synthesis in response to wounding and proinflammatory cytokines in human peritoneal mesothelial cells. In addition, in vivo models and human peritoneal biopsy samples have provided evidence of changes in HA metabolism in the fibrosis that at present accompanies peritoneal dialysis treatment. This review discusses these published observations and how they might contribute to improvement in peritoneal dialysis.