Tissue-specific alternative splicing and expression of ATP1B2 gene

The Na+-K+-ATPase is an essential transport enzyme expressed in all animal tissues, where it generates ion gradients to maintain membrane potential and drive the transport of other solutes. It also balances metabolism and body temperature. In this study, the characterization of three novel bovine ATP1B2 splice variants, designated as ATP1B2-AS1, ATP1B2-AS2, and ATP1B2-AS3, is discussed. All three novel splice isoforms were derived from a complete transcript (ATP1B2-complete) by alternative splicing. The pattern of splicing to produce the ATP1B2-AS1 and ATP1B2-AS2 isoforms was intron retention; these isoforms were found in liver, kidney, muscle and breast tissues. For the ATP1B2-AS3 isoform, splicing was by exon inclusion and this isoform was only found in muscle tissue. As demonstrated by real-time polymerase chain reaction, the isoforms were all expressed at significantly lower levels than the complete ATP1B2 gene transcript in all the tissues studied. After heat-stress, the expression levels of the different transcripts were lower in different tissues; however, the expression of the ATP1B2-complete transcript increased in heart and lung tissues. The results of this research provide some useful information for further studies into the function of the bovine ATP1B2 gene. Alternative splicing (AS) is recognized as the major contributor to protein diversity from limited gene pool. ATP1B2-AS2 was the splice of intron retention found from ATP1B2 in liver, kidney, muscle and breast tissues. In the study, ATP1B2-AS2 showed that many of the amino acid residues were in an unfavorable energy environment. It is interesting to speculate that this may be the perfect transcript to respond to heat-stress. So, AS may become the appropriate pathway to tackle heat-stress and reduce the economic losses in cows.Key words: ATP1B2 gene, alternative splicing, alternative splicing mechanism

Inhibition of Histone Deacetylases Prevents Cardiac Remodeling After Myocardial Infarction by Restoring Autophagosome Processing in Cardiac Fibroblasts

Background/Aims: Histone deacetylases (HDACs) play a critical role in the regulation of gene transcription, cardiac development, and diseases. The aim of this study was to investigate whether the inhibition of HDACs improves cardiac remodeling and its underlying mechanisms in a mouse myocardial infarction (MI) model. Methods: The HDAC inhibitor trichostatin A (TSA, 0.1 mg/kg/day) was administered via daily intraperitoneal injections for 8 consecutive weeks after MI in C57/BL mice. Echocardiography and tissue histopathology were used to assess cardiac function. Cultured neonatal rat cardiac fibroblasts (NRCFs) were subjected to simulated hypoxia in vitro. Autophagic flux was measured using the tandem fluorescent mCherry-GFP-LC3 assay. Western blot was used to detect autophagic biomarkers. Results: After 8 weeks, the inhibition of HDACs in vivo resulted in improved cardiac remodeling and hence better ventricular function. MI was associated with increased LC3-II expression and the accumulation of autophagy adaptor protein p62, indicating impaired autophagic flux, which was reversed by TSA treatment. Cultured NRCFs exhibited increased cell death after simulated hypoxia in vitro. Increased cell death was associated with markedly increased numbers of autophagosomes but not autolysosomes, as assessed by punctate dual fluorescent mCherry-green fluorescent protein tandem-tagged light chain-3 expression, indicating that hypoxia resulted in impaired autophagic flux. Importantly, TSA treatment reversed hypoxia-induced impaired autophagic flux and led to a 40% decrease in cell death. This was accompanied by improved mitochondrial membrane potential. The beneficial effects of TSA therapy were abolished by RNAi intervention targeting LAMP2; likewise, in vivo delivery of chloroquine abolished the TSA-mediated cardioprotective effects. Conclusion: Our results provide evidence that the HDAC inhibitor TSA prevents cardiac remodeling after MI and is dependent on restoring autophagosome processing of cardiac fibroblasts

MiRNA-Directed Regulation of VEGF and Other Angiogenic Factors under Hypoxia

MicroRNAs (miRNAs) are a class of 20–24 nt non-coding RNAs that regulate gene expression primarily through post-transcriptional repression or mRNA degradation in a sequence-specific manner. The roles of miRNAs are just beginning to be understood, but the study of miRNA function has been limited by poor understanding of the general principles of gene regulation by miRNAs. Here we used CNE cells from a human nasopharyngeal carcinoma cell line as a cellular system to investigate miRNA-directed regulation of VEGF and other angiogenic factors under hypoxia, and to explore the principles of gene regulation by miRNAs. Through computational analysis, 96 miRNAs were predicted as putative regulators of VEGF. But when we analyzed the miRNA expression profile of CNE and four other VEGF-expressing cell lines, we found that only some of these miRNAs could be involved in VEGF regulation, and that VEGF may be regulated by different miRNAs that were differentially chosen from 96 putative regulatory miRNAs of VEGF in different cells. Some of these miRNAs also co-regulate other angiogenic factors (differential regulation and co-regulation principle). We also found that VEGF was regulated by multiple miRNAs using different combinations, including both coordinate and competitive interactions. The coordinate principle states that miRNAs with independent binding sites in a gene can produce coordinate action to increase the repressive effect of miRNAs on this gene. By contrast, the competitive principle states when multiple miRNAs compete with each other for a common binding site, or when a functional miRNA competes with a false positive miRNA for the same binding site, the repressive effects of miRNAs may be decreased. Through the competitive principle, false positive miRNAs, which cannot directly repress gene expression, can sometimes play a role in miRNA-mediated gene regulation. The competitive principle, differential regulation, multi-miRNA binding sites, and false positive miRNAs might be useful strategies in the avoidance of unwanted cross-action among genes targeted by miRNAs with multiple targets

Metabolic syndrome and risk of subclinical hypothyroidism: a systematic review and meta-analysis

BackgroundSubclinical hypothyroidism (SCH) is a common endocrine subclinical disorder, the main adverse consequences of which are the development of clinical hypothyroidism and the promotion of ischemic heart disease. Metabolic syndrome (MetS) is a collection of metabolic problems. The goal of this meta-analysis was to evaluate the relationship between MetS and SCH.MethodsSuitable publications were identified using PubMed, Embase, and the Cochrane Library. The meta-analysis included only studies in English that reported odds ratio (OR) data for MetS and SCH. Two researchers combined data using a random-effects model. OR and 95% confidence intervals (CIs) were used to present the results.ResultsMetS was associated with an elevated risk of developing SCH (OR 2.56, 95% CI 1.44–4.55). However, the individual components of MetS were not associated with the risk of SCH. Subgroup analysis revealed that different definitions of MetS had varying effects on SCH. Sensitivity analysis confirmed that our results were robust.ConclusionsThis meta-analysis indicates that patients with MetS have an increased risk of SCH, while there is no significant association between the five individual components of MetS and the risk of SCH.Systematic review registrationhttps://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023454415

Identification of forensically important sarcophagid flies (Diptera: Sarcophagidae) based on COI gene in China

Abstract: Identifing an insect specimen is a crucial step in forensic entomology. As the stages and species of insect discovered on a corpse, such as Calliphoridae and Sarcophagidae, provides evidence for estimation of postmortem interval (PMI). However, morphologically distinguish may on occasion be impossible to the adult flies and nymphs of the same genus. A molecular method used the cytochrome oxidase subunits one (COI) sequence on mitochondrial DNA was established for sarcophagid species identification. In this study, a 272 base pair region of mitochondrial DNA (mtDNA) coding for COI was investigated for identification of the following forensically important sarcophagid flies. The specimens were from four families, including 8 Boerttcherisca Peregrina (Robineau -Desvoidy,1830) specimens of Boettcherisca, 2 Parasarcophaga similis (Meade, 1876) specimens, 4 Parasarcophaga albiceps (Meigen, 1826) and 8 Parasarcophaga dux (Thompson, 1869) specimens from Parasarcophaga. Phylogenetic analysis indicates that this partial COI region successfully identified all samples species to species group. Low levels of variation between some species indicate that sarcophagid flies from more locations should be studied in the future and local database set up are strongly recommended in China

Searching for Black Hole Candidates by LAMOST and ASAS-SN

Most dynamically confirmed stellar-mass black holes (BHs) and their candidates were originally selected from X-ray outbursts. In the present work, we search for BH candidates in the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) survey using the spectra along with photometry from the All Sky Automated Survey for SuperNovae (ASAS-SN), where the orbital period of the binary may be revealed by the periodic light curve, such as the ellipsoidal modulation type. Our sample consists of nine binaries, where each source contains a giant star with large radial velocity variation (ΔV_R ≳ 70 km s^(-1)) and periods known from light curves. We focus on the nine sources with long periods (T_(ph) > 5 days) and evaluate the mass M_2 of the optically invisible companion. Since the observed ΔV_R from only a few repeating spectroscopic observations is a lower limit of the real amplitude, the real mass M_2 can be significantly higher than the current evaluation. It is likely an efficient method to place constraints on M 2 by combining ΔV_R from LAMOST and T_(ph) from ASAS-SN, particularly by the ongoing LAMOST Medium Resolution Survey