Identification of miR-1 and miR-499 in chronic atrial fibrillation by bioinformatics analysis and experimental validation.

Background: Atrial fibrillation (AF) is one of the most prevalent arrhythmias and is characterized by a high risk of heart failure and embolic stroke, yet its underlying mechanism is unclear. The primary goal of this study was to establish a miRNA-mRNA network and identify the miRNAs associated with chronic AF by bioinformatics and experimental validation. Methods: The GSE79768 dataset was collected from the Gene Expression Omnibus(GEO) database to extract data from patients with or without persistent AF. Differentially expressed genes (DEGs) were identified in left atrial appendages (LAAs). The STRING platform was utilized for protein-protein interaction (PPI) network analysis. The target miRNAs for the top 20 hub genes were predicted by using the miRTarBase Web tool. The miRNA-mRNA network was established and visualized using Cytoscape software. The key miRNAs selected for verification in the animal experiment were confirmed by miRwalk Web tool. We used a classic animal model of rapid ventricular pacing for chronic AF. Two groups of animals were included in the experiment, namely, the ventricular pacing group (VP group), where ventricular pacing was maintained at 240-280 bpm for 2 weeks, and the control group was the sham-operated group (SO group). Finally, we performed reverse transcription-quantitative polymerase chain reaction (RT-qPCR) to validate the expression of miR-1 and miR-499 in LAA tissues of the VP group and the SO group. Left atrial fibrosis and apoptosis were evaluated by Masson staining and caspase-3 activity assays, respectively. Results: The networks showed 48 miRNAs in LAA tissues. MiR-1 and miR-499 were validated using an animal model of chronic AF. The expression level of miR-1 was increased, and miR-499 was decreased in VP group tissues compared to SO group tissues in LAAs (P < 0.05), which were correlated with left atrial fibrosis and apoptosis in AF. Conclusion: This study provides a better understanding of the alterations in miRNA-1 and miR-499 in chronic AF from the perspective of the miRNA-mRNA network and corroborates findings through experimental validation. These findings may offer novel potential therapeutic targets for AF in the future.

Targeted Screening of Curcumin Derivatives as Pancreatic Lipase Inhibitors Using Computer-Aided Drug Design.

Curcumin has demonstrated promising preclinical antiobesity effects, but its low bioavailability makes it difficult to exert its full effect at a suitable dose. The objective of this study was to screen curcumin derivatives with enhanced bioavailability and lipid-lowering activity under the guidance of computer-aided drug design (CADD). CAAD was used to perform virtual assays on curcumin derivatives to assess their pharmacokinetic properties and effects on pancreatic lipase activity. Subsequently, 19 curcumin derivatives containing 5 skeletons were synthesized to confirm the above virtual assay. The in vitro pancreatic lipase inhibition assay was employed to determine the half-maximal inhibitory concentration (IC50) of these 19 curcumin derivatives. Based on CADD analysis and in vitro pancreatic lipase inhibition, 2 curcumin derivatives outperformed curcumin in both aspects. Microscale thermophoresis (MST) experiments were employed to assess the binding equilibrium constants (K d) of the aforementioned 2 curcumin derivatives, curcumin, and the positive control drug with pancreatic lipase. Through virtual screening utilizing a chemoinformatics database and molecular docking, 6 derivatives of curcumin demonstrated superior solubility, absorption, and pancreatic lipase inhibitory activity compared to curcumin. The IC50 value for 1,7-bis(4-hydroxyphenyl)heptane-3,5-dione (C4), which displayed the most effective inhibitory effect, was 42.83 µM, while the IC50 value for 1,7-bis(4-hydroxy-3-methoxyphenyl)heptane-3,5-dione (C6) was 98.62 µM. On the other hand, the IC50 value for curcumin was 142.24 µM. The MST experiment results indicated that the K d values of C4, C6, and curcumin were 2.91, 18.20, and 23.53 µM, respectively. The results of the activity assays exhibited a relatively high degree of concordance with the outcomes yielded by CADD screening. Under the guidance of CADD, the targeted screening of curcumin derivatives with excellent properties in this study exhibited high-efficiency and low-cost benefits.

Two-Dimensional Amphibian Diversity along a 3500 m Elevational Gradient at the Eastern Edge of the Qinghai-Xizang Plateau.

Amphibians serve as reliable indicators of ecosystem health and are the most threatened group of vertebrates. Studies on their spatial distribution pattern and threats are crucial to formulate conservation strategies. Gongga Mountains, with a peak at 7509 m a.s.l. and running latitudinally, are in the center of the Hengduan Mountains Range and at the eastern steep edge of the Qinghai-Xizang Plateau, providing heterogeneous habitats and varied niches for amphibians. In this study, we combined 83 days of field work with information from 3894 museum specimens that were collected over the past 80 years, and identified twenty amphibian species belonging to seven families and twelve genera by morphology. Of these species, seven were listed in the threatened categories of the Red List of China's Biodiversity and thirteen were endemic to China. Ten species were found on the plateau side (western slope) and eleven species were found on the other side close to the Sichuan Basin (eastern slope). Only one species was found on both sides, indicating different community structures horizontally. The species richness was unimodal vertically and peaking at mid elevation on both sides, with the maximum number (ten vs. nine) of species occurring at 3300-3700 vs. 1700-1900 m a.s.l. and in different types of vegetation. The elevation span and body length of species distributed on both slopes did not show significant differences. These findings help to understand the horizontal and vertical distribution pattern of amphibian diversity, laying a foundation for future biogeographical and conservation research in this area.

Human beta defensin 3 knockdown inhibits the proliferation and migration of airway smooth muscle cells through regulating the PI3K/AKT signaling pathway.

Asthma, a common pediatric pulmonary disease, significantly affects children's healthy development. This study aimed to investigate the functions of human ß defensin-3 (HBD-3) in asthma progression. For this purpose, blood samples from asthmatic and healthy children were collected. Moreover, the airway smooth muscle cells (ASMCs) were treated with platelet-derived growth factor BB (PDGF-BB) to develop an in vitro asthma model, then evaluated cell viability and migration via CCK-8 and transwell assays. The mRNA levels of interferon γ (INF-γ), interleukin 4 (IL-4), interleukin 10 (IL-10), alpha-smooth muscle actin (α-SMA), HBD-3, and the protein levels of phosphatidylinositol 3-kinase (PI3K) along with protein kinase B (AKT) were detected. Similarly, the N6-methyladenosine (m6A) content in the ASMCs and m6A levels of HBD-3 were also measured. Results indicated an upregulated HBD-3 in the asthmatic children. The ASMCs were found to be stimulated by PDGF-BB, in addition to the promotion of cell viability and migration. The INF-γ, IL-4, and α-SMA levels were reduced, while IL-10 was elevated in PDGF-BB-stimulated ASMCs. Silencing HBD-3 in PDGF-BB stimulated ASMCs was found to exert the opposite effect by inhibiting cell viability and migration, enhancing the levels of INF-γ, IL-4, and α-SMA, while the IL-10 levels were found to decline. PDGF-BB stimulation of ASMCs resulted in activation of the PI3K/AKT signaling pathway, which was blocked post HBD-3 silencing, while the role of si-hBD in PDGF-BB stimulated ASMCs was neutralized post-treatment with IGF-1. Finally, it was found that METTL3 overexpression prominently upregulated the m6A levels of HBD-3 and decreased the mRNA expression and stability of HBD-3 in the PDGF-BB-stimulated ASMCs. The study concluded that METTL3-mediated HBD-3 participates in the progression of asthma through the PI3K/AKT signaling pathway.

Vitamin D receptor (VDR) variants are risk factors for ovarian cancer: a meta-analysis and trial sequential analysis.

The importance of Vitamin D in ovarian cancer (OC) has been well documented, and lower levels have been associated with susceptibility to OC. Vitamin D exerts its effect through the vitamin D receptor (VDR). Common genetic variants in the VDR gene (Fok I, TaqI, BamI and ApaI) have been linked with the susceptibility to the development of OC; however, the reports remain contradictory. To draw a valid conclusion, we performed a meta-analysis of the earlier published reports in the present study. The literature search was performed in PubMed, Google Scholar, and Scopus databases. All relevant articles were screened, and eligible reports were identified based on prefixed inclusion and exclusion criteria. Data such as author's details, year of publication, ethnicity, genotype and allele prevalence in cases and controls were extracted from the eligible reports. The meta-analysis was performed using Comprehensive Meta-analysis Software (CMA) V3. Eight articles, including data from fourteen independent cohorts, comprised 4276 cases and 6739 healthy controls considered for the analysis. VDR FokI and BamI variants revealed a significant association with an increased risk of OC. Other VDR polymorphisms (TaqI and ApaI) failed to demonstrate such an association with OC. Interestingly, the sensitivity analysis revealed minimal deviation from the parent meta-analysis, supporting the robustness of the present analysis. The trial sequential analysis revealed the inclusion of a sufficient number of studies for FokI polymorphism. It highlighted the requirement for additional case-control studies in VDR (ApaI, BamI and TaqI) to draw a definitive conclusion. FokI and BamI polymorphisms are associated with susceptibility to OC.

Effect of food and polymorphisms in SLCO2B1, CYP3A4 and UGT1A4 on pharmacokinetics of abiraterone and its metabolites in Chinese volunteers.

AIMS: Abiraterone acetate, a prodrug of abiraterone (ABI), provides an efficient therapeutic option for metastatic castration-resistant prostate cancer patients. ABI undergoes extensive metabolism in vivo and is transformed into active metabolites Δ4 -abiraterone and 3-keto-5α-abiraterone as well as inactive metabolites abiraterone sulfate and abiraterone N-oxide sulfate. We aimed to examine the effect of polymorphisms in SLCO2B1, CYP3A4 and UGT1A4 on the pharmacokinetics of ABI and its metabolites. METHODS: In this study, 81 healthy Chinese subjects were enrolled and divided into 2 groups for fasted (n = 45) and fed (n = 36) studies. Plasma samples were collected after administering a 250 mg abiraterone acetate tablet followed by liquid chromatography-tandem mass spectrometry analysis. Genotyping was performed on a MassARRAY system. The association between SLCO2B1, CYP3A4, UGT1A4 genotype and pharmacokinetic parameters of ABI and its metabolites was assessed. RESULTS: Food effect study demonstrated high fat meal remarkedly increased systemic exposure of ABI and its metabolites. The geometric mean ratio and 90% confidence interval of area under the plasma concentration-time curve from time 0 to the time of the last quantifiable concentration (AUC0-t ) and maximum plasma concentration (Cmax ) of ABI in fed state vs. fasted state were 351.64% (286.86%-431.04%) and 478.45% (390.01%-586.94%), respectively, while the corresponding results were ranging from 145.11% to 269.42% and 150.10% to 478.45% for AUC0-t and Cmax of ABI metabolites in fed state vs. fasted state, respectively. The SLCO2B1 rs1077858 had a significant influence on AUC0-t and Cmax , while 7 other SLCO2B1 variants prolonged half-life of ABI under both fasted and fed conditions. As for ABI metabolites, the systemic exposure of Δ4 -abiraterone, abiraterone sulfate and abiraterone N-oxide sulfate as well as the elimination of 3-keto-5α-abiraterone were significantly affected by SLCO2B1 polymorphisms. Polymorphisms in CYP3A4 and UGT1A4 did not significantly affect pharmacokinetics of ABI and its metabolites. CONCLUSION: Polymorphisms in SLCO2B1 were significantly related to the pharmacokinetic variability of ABI and its metabolites under both fasted and fed conditions.

Transcriptome profile of subsynaptic myonuclei at the neuromuscular junction in embryogenesis.

Skeletal muscle fiber is a large syncytium with multiple and evenly distributed nuclei. Adult subsynaptic myonuclei beneath the neuromuscular junction (NMJ) express specific genes, the products of which coordinately function in the maintenance of the pre- and post-synaptic regions. However, the gene expression profiles that promote the NMJ formation during embryogenesis remain largely unexplored. We performed single-nucleus RNA sequencing (snRNA-seq) analysis of embryonic and neonatal mouse diaphragms, and found that each myonucleus had a distinct transcriptome pattern during the NMJ formation. Among the previously reported NMJ-constituting genes, Dok7, Chrna1, and Chrnd are specifically expressed in subsynaptic myonuclei at E18.5. In the E18.5 diaphragm, ca. 10.7% of the myonuclei express genes for the NMJ formation (Dok7, Chrna1, and Chrnd) together with four representative ß-catenin regulators (Amotl2, Ptprk, Fam53b, and Tcf7l2). Additionally, the temporal gene expression patterns of these seven genes are synchronized in differentiating C2C12 myoblasts. Amotl2 and Ptprk are expressed in the sarcoplasm, where ß-catenin serves as a structural protein to organize the membrane-anchored NMJ structure. In contrast, Fam53b and Tcf7l2 are expressed in the myonucleus, where ß-catenin serves as a transcriptional coactivator in Wnt/ß-catenin signaling at the NMJ. In C2C12 myotubes, knockdown of Amotl2 or Ptprk markedly, and that of Fam53b and Tcf7l2 less efficiently, impair the clustering of acetylcholine receptors. In contrast, knockdown of Fam53b and Tcf7l2, but not of Amotl2 or Ptprk, impairs the gene expression of Slit2 encoding an axonal attractant for motor neurons, which is required for the maturation of motor nerve terminal. Thus, Amotl2 and Ptprk exert different roles at the NM compared to Fam53b and Tcf7l2. Additionally, Wnt ligands originating from the spinal motor neurons and the perichondrium/chondrocyte are likely to work remotely on the subsynaptic nuclei and the myotendinous junctional nuclei, respectively. We conclude that snRNA-seq analysis of embryonic/neonatal diaphragms reveal a novel coordinated expression profile especially in the Wnt/ß-catenin signaling that regulate the formation of the embryonic NMJ.

First-in-human trial of SAR107375E, a novel small molecule anticoagulant with dual inhibition of factor Xa and factor IIa.

BACKGROUND: SAR107375E is a direct dual inhibitor of both Factor Xa and Factor IIa and has shown potent anticoagulation activity in vitro and animals. This study evaluated the safety, tolerability, pharmacokinetics, and pharmacodynamics of single ascending intravenous doses of SAR107375E in healthy Chinese adult subjects. METHODS: In this randomized, double-blind, placebo-controlled trial, 60 healthy Chinese adult subjects were administered intravenously single ascending doses (0.5, 1.5, 3.0, 5.0, 7.5, 10.0, 15.0, or 20.0 mg) of SAR107375E (N = 44) or placebo (N = 16). Plasma and urine concentrations of SAR107375E were measured and used to calculate pharmacokinetic parameters. Coagulation functions were measured and compared with baseline values. Treatment-emergent adverse events were recorded to evaluate safety. RESULTS: In plasma, from the 0.5 to 20.0 mg dose group, t1/2 is 1.51-4.00 h, Cmax is 59.05-1360 ug/L, and AUC0-t is 25.01-528.45 h*ug/L. And it shows dose proportionality in the 5.0-20.0 mg range. Activated partial thromboplastin time and Ecarin clotting time correlated linearly with drug plasma concentration. No serious adverse events were reported during the study. CONCLUSION: SAR107375E exhibits good safety and tolerability, predictable pharmacokinetics and pharmacodynamics. CLINICAL TRIAL REGISTRATION: www.chinadrugtrials.org.cn, identifier is CTR20211082.

MiR-26a-5p Heightens Breast Cancer Cell Sensitivity to Paclitaxel via Targeting Flap Endonuclease 1.

OBJECTIVE: Flap endonuclease 1 (FEN1) has been confirmed to involve the drug resistance of multiple cancers including breast cancer. However, the effect of miRNA-mediated FEN1 on breast cancer cell resistance is still ambiguous and needs further research. METHODS: Firstly, we used GEPIA2 to predict the FEN1 expression in breast cancer. Next, we used quantitative real-time polymerase chain reaction (qRT-PCR) and western blot to evaluate the FEN1 level of cells. After parental cells or MDA-MB-231-paclitaxel (PTX) cells being transfected with or without siFEN1, the apoptosis, migration, and protein levels of FEN1, Bcl-2, and resistance-related genes were examined by flow cytometry, wound healing assay, and western blot, respectively. Then, the putative miRNA targeting FEN1 was predicted using StarBase V3.0, and further confirmed by qRT-PCR. The targeted binding of FEN1 to miR-26a-5p was detected by dual-luciferase reporter assay. After parental cells or MDA-MB-231-PTX cells being transfected with or without miR-26a-5p mimic, the apoptosis, migration, and protein levels of FEN1, Bcl-2, and resistance-related genes were tested again. RESULTS: FEN1 expression was enhanced in breast cancer and MDA-MB-231-PTX cells. The combined application of FEN1 knockdown and PTX enhanced apoptosis in MDA-MB-231-PTX cells but suppressed cell migration and expressions of FEN1, Bcl-2, and resistance-related genes. Then, we confirmed that FEN1 was targeted by miR-26a-5p. The combined application of miR-26a-5p mimic and PTX largely facilitated apoptosis in MDA-MB-231-PTX cells but restrained cell migration and expressions of FEN1, Bcl-2, and resistance-related genes. CONCLUSION: MiR-26a-5p contributes to the sensitivity of breast cancer cells to paclitaxel via restraining FEN1.

Transposable element and host silencing activity in gigantic genomes.

Transposable elements (TEs) and the silencing machinery of their hosts are engaged in a germline arms-race dynamic that shapes TE accumulation and, therefore, genome size. In animal species with extremely large genomes (>10 Gb), TE accumulation has been pushed to the extreme, prompting the question of whether TE silencing also deviates from typical conditions. To address this question, we characterize TE silencing via two pathways-the piRNA pathway and KRAB-ZFP transcriptional repression-in the male and female gonads of Ranodon sibiricus, a salamander species with a ∼21 Gb genome. We quantify 1) genomic TE diversity, 2) TE expression, and 3) small RNA expression and find a significant relationship between the expression of piRNAs and TEs they target for silencing in both ovaries and testes. We also quantified TE silencing pathway gene expression in R. sibiricus and 14 other vertebrates with genome sizes ranging from 1 to 130 Gb and find no association between pathway expression and genome size. Taken together, our results reveal that the gigantic R. sibiricus genome includes at least 19 putatively active TE superfamilies, all of which are targeted by the piRNA pathway in proportion to their expression levels, suggesting comprehensive piRNA-mediated silencing. Testes have higher TE expression than ovaries, suggesting that they may contribute more to the species' high genomic TE load. We posit that apparently conflicting interpretations of TE silencing and genomic gigantism in the literature, as well as the absence of a correlation between TE silencing pathway gene expression and genome size, can be reconciled by considering whether the TE community or the host is currently "on the attack" in the arms race dynamic.

High-Throughput Metabolic Soft-Spot Identification in Liver Microsomes by LC/UV/MS: Application of a Single Variable Incubation Time Approach.

CYP-mediated fast metabolism may lead to poor bioavailability, fast drug clearance and significant drug interaction. Thus, metabolic stability screening in human liver microsomes (HLM) followed by metabolic soft-spot identification (MSSID) is routinely conducted in drug discovery. Liver microsomal incubations of testing compounds with fixed single or multiple incubation time(s) and quantitative and qualitative analysis of metabolites using high-resolution mass spectrometry are routinely employed in MSSID assays. The major objective of this study was to develop and validate a simple, effective, and high-throughput assay for determining metabolic soft-spots of testing compounds in liver microsomes using a single variable incubation time and LC/UV/MS. Model compounds (verapamil, dextromethorphan, buspirone, mirtazapine, saquinavir, midazolam, amodiaquine) were incubated at 3 or 5 µM with HLM for a single variable incubation time between 1 and 60 min based on predetermined metabolic stability data. As a result, disappearances of the parents were around 20-40%, and only one or a few primary metabolites were generated as major metabolite(s) without notable formation of secondary metabolites. The unique metabolite profiles generated from the optimal incubation conditions enabled LC/UV to perform direct quantitative estimation for identifying major metabolites. Consequently, structural characterization by LC/MS focused on one or a few major primary metabolite(s) rather than many metabolites including secondary metabolites. Furthermore, generic data-dependent acquisition methods were utilized to enable Q-TOF and Qtrap to continuously record full MS and MS/MS spectral data of major metabolites for post-acquisition data-mining and interpretation. Results from analyzing metabolic soft-spots of the seven model compounds demonstrated that the novel MSSID assay can substantially simplify metabolic soft-spot identification and is well suited for high-throughput analysis in lead optimization.

Binaprofen induces zebrafish liver injury via the mitochondrial pathway.

Binaprofen (C18H23NO5) is a drug not commercially available that causes liver injury; however, the underlying mechanism is unknown. The aim of the present study was to determine the mechanism underlying binaprofen­induced liver injury at the genetic level. Zebrafish were treated with binaprofen. Serum biomarkers [alanine transaminase (ALT), aspartate transaminase (AST) and lactate dehydrogenase (LDH)], malondialdehyde (MDA) and glutathione (GSH) content analysis, liver cell morphology examination, DAPI staining, electron microscopy, microarray analysis and reverse transcription­quantitative (RT­q)PCR were performed 12, 24 and 48 h post­treatment to analyze the mechanism underlying binaprofen­induced liver injury. Following exposure to binaprofen, zebrafish serum levels of ALT, AST and LDH increased; MDA content of liver tissue increased and GSH content decreased. Liver cells exhibited mild to moderate vacuolization and mitochondria exhibited vacuolization and disrupted cristae. Liver cell apoptosis rate increased. There were 190 common differentially expressed genes at 12, 24 and 48 h. Gene Ontology analysis showed that the function of downregulated genes was primarily associated with 'DNA replication', 'DNA metabolic process', 'cell cycle', 'cell redox homeostasis', 'mitochondrion' and 'lipid transport'. The function of upregulated genes was primarily associated with 'peroxisome proliferator', 'oxidation activity', 'peroxisome' and 'apoptosis'. Pathway analysis showed that downregulated genes were those pertaining to 'cell cycle', 'DNA replication', 'ribosome', 'spliceosome', 'pyrimidine metabolism', 'purine metabolism', upregulated genes were those pertaining to 'PPAR signaling pathway', 'p53 signaling pathway'; RT­qPCR assay supported the microarray results. The mechanism underlying binaprofen­induced liver injury was associated with lipid peroxidation and apoptosis. Binaprofen downregulated genes associated with lipid transport and anti­apoptosis genes, upregulated pro­apoptosis genes and induces liver cell injury via the mitochondrial signaling pathway.

Simultaneous determination of abiraterone and its five metabolites in human plasma by LC-MS/MS: Application to pharmacokinetic study in healthy Chinese subjects.

In this study, a rapid, simple and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated to simultaneously quantify abiraterone (ABI), a widely used anti-metastatic castration-resistant prostate cancer drug, and its metabolites comprising Δ4-abiraterone (D4A), 3-keto-5α-abiraterone (5αA), abiraterone N-oxide (A-NO), abiraterone sulfate (A-Sul) and abiraterone N-oxide sulfate (A-NO-Sul) in human plasma. The analytes were extracted by protein precipitation with acetonitrile and ideal chromatographic separation was achieved on ACE-C18 column (2.1 × 50 mm, 5 µm) using a gradient elution. Triple Quad™ 6500+ mass spectrometer equipped with an electrospray ionization (ESI) source was used and the multiple reaction mode (MRM) was performed. In terms of method validation, good linearity was observed in preassigned validated concentration range for each analyte of interest. Both intra- and inter-batch accuracy was within the range of 87.6-113.8% for all analytes, while intra- and inter-batch precision was below 14.0%. Additionally, both low matrix effects and high recovery were obtained. All analytes remained stable in human plasma at room temperature for 4 h, on wet ice for 8 h, at - 80 °C for 42 d, over three freeze-thaw cycles and under auto-sampler temperature (4 °C) for 48 h post sample preparation. Subsequently, the validated LC-MS/MS method was applied for pharmacokinetic study in healthy Chinese volunteers following an oral dose of 250 mg abiraterone acetate tablet under fasted conditions. Our study for the first time reported the pharmacokinetic parameters of the ABI metabolites in Chinese subjects.

Characterization and mutagenesis of a novel Mycobacterium smegmatis-derived glutamate decarboxylase active at neutral pH.

γ-aminobutyric acid (GABA) has various physiological functions and is widely used in medicine, food, and other fields. Glutamate decarboxylase (GAD) is a key enzyme that catalyzes the decarboxylation of L-glutamate to synthesize GABA. However, the industrial application of microorganism-derived GAD is limited by its rapid loss of enzymatic activity with pH approaching neutrality. In this study, a novel glutamate decarboxylase, GADMSM, from Mycobacterium smegmatis was overexpressed and purified. On the basis of homologous modeling and substrate molecular docking, several GADMSM mutants were constructed, and their enzymatic properties were analyzed. The results showed that the optimal pH of wild-type GADMSM is 5.4; at pH 6.2, 22.8% enzymatic activity was retained. The T211I replacement in GAD and C-terminal deletion mutant GADMSMΔC showed relatively high catalytic activity in a pH range of 5.0-7.0. The Vmax and Km values of GADMSMΔC were 14.69 and 5.70, respectively, at pH 5.5, and 9.87 and 6.17, respectively, at pH 7.0. Compared with the wild-type GAD, GADMSMΔC maintained higher affinity and enzymatic activity of the substrate, maintaining 78.5% of the highest enzymatic activity even at pH 7.0, which is the highest reported activity retention for GAD under neutral pH condition. Therefore, GADMSMΔC can be used for the transformation of high-yielding strains and industrial production of GABA.

Aliidiomarina halalkaliphila sp. nov., a haloalkaliphilic bacterium isolated from a soda lake in Inner Mongolia Autonomous Region, China.

A haloalkaliphilic strain (IM 1326T) was isolated from brine sampled at a soda lake in the Inner Mongolia Autonomous Region, China. Cells of the strain were rod-shaped and motile. Strain IM 1326T was able to grow at 4-42 °C (optimum, 37 °C) with 0-13.0 % (w/v) NaCl concentrations (optimum at 4.0-6.0 %) and at pH 7.5-11.0 (optimum at 9.0-10.0). The 16S rRNA gene phylogenetic analysis revealed that the isolate belongs to the genus Aliidiomarina and is closely related to the type strains of Aliidiomarina sanyensis (95.8 % sequence similarity), Aliidiomarina shirensis (95.7 %), Aliidiomarina iranensis (95.4 %) and Aliidiomarina haloalkalitolerans (95.3 %). The whole genome of strain IM 1326T was sequenced, and the genomic DNA G+C content was 49.7 mol%. Average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization values between the isolate and the related Aliidiomarina species were 68.1-84.9 %, 76-78 % and 18.4-20.4 %, respectively. The respiratory quinone was ubiquinone-8. The polar lipid profile included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and one unidentified aminophospholipid. The predominant cellular fatty acids were summed feature 9 (10-methyl-C16 : 0/iso-C17 : 1 ω9c, 22.2 %), iso-C15 : 0 (16.1 %) and iso-C17 : 0 (13.1 %). Based on the results of phylogenetic analysis, genome relatedness, and the physiological and chemotaxonomic properties of the isolate, strain IM 1326T is considered to represent a novel species of the genus Aliidiomarina, for which the name Aliidiomarina halalkaliphila sp. nov. is proposed (type strain IM 1326T=CGMCC 1.17056T=JCM 34227T).

Complete mitochondrial genome of the spectacled parrotbill Sinosuthora conspicillata David, 1871 (Aves: Passeriformes: Sylviidae).

The mitochondrial genome of the spectacled parrotbill Sinosuthora conspicillata is sequenced by the Sanger method. The genome is 16,982 bp in length, comprising of 13 protein-coding genes (PCGs), 2 rRNA genes, 22 tRNA genes, 1 control region (D-loop), and 1 pseudo-control region. The PCGs of COX1 and ND3 use GTG and ATA as their starting codon, respectively, while all other PCGs start with ATG codons. Four PCGs (COX3, ND4, ND5, and ND6) are terminated with CCT, TAT, AGA, and TAG, respectively, and all other PCGs end with TAA. The 22 tRNAs range from 66 bp (tRNA-Ser) to 75 bp (tRNA-Leu) in length. The two rRNAs are 984 bp (12S) and 1600 bp (16S) in length. Phylogenetic analysis indicated that S. conspicillata is closely related to the congeneric vinous-throated parrotbill S. webbiana. This mitochondrial genome sequence offers a valuable resource for future conservation genetic and phylogenetic studies of birds in the family Sylviidae (Passeriformes).

Self-management behavior and fasting plasma glucose control in patients with type 2 diabetes mellitus over 60 years old: multiple effects of social support on quality of life.

OBJECTIVE: Elderly patients with type 2 diabetes mellitus are highly vulnerable due to severe complications. However, there is a contradiction in the relationship between social support and quality of life, which warrants further exploration of the internal mechanism. This study assessed the quality of life and its interfering factors in this patient population. METHODS: In total, 571 patients with type 2 diabetes mellitus over 60 years old were recruited from two community clinics in Heilongjiang Province, China. We collected data on health status, quality of life, self-management behavior, fasting plasma glucose (FPG) level, and social support. Structural equation modeling and the bootstrap method were used to analyze the data. RESULTS: The average quality of life score was - 29.25 ± 24.41. Poorly scored domains of quality of life were "Psychological feeling" (- 8.67), "Activity" (- 6.36), and "Emotion" (- 6.12). Of the 571 patients, 65.32% had normal FPG, 9.8% had high-risk FPG, 15.94% had good self-management behavior, and 22.07% had poor social support. Significant correlations among social support, self-management behavior, FPG level, and quality of life were noted. A multiple mediator model revealed that social support influenced quality of life in three ways: (1) directly (c' = 0.6831); (2) indirectly through self-management behavior (a1*b1 = 0.1773); and (3) indirectly through FPG control (a2*b2 = 0.1929). Self-management behavior influenced the quality of life directly and indirectly through FPG control. CONCLUSION: Improving self-management behavior and monitoring hypoglycemia should become priority targets for future intervention. Scheduled social support to self-management projects should be put into the standardized management procedure. Physicians should provide substantial and individualized support to the elderly patients with type 2 diabetes mellitus regarding medication, blood glucose monitoring, and physical exercise.

Myrtenol alleviates oxidative stress and inflammation in diabetic pregnant rats via TLR4/MyD88/NF-κB signaling pathway.

Gestational diabetes mellitus (GDM) is a special kind of diabetes that arises only during pregnancy. A woman with GDM has a higher risk of developing type-2 diabetes and other metabolic diseases. In this exploration, we intended to scrutinize the therapeutic actions of Myrtenol against the streptozotocin (STZ)-provoked GDM in rats. GDM was provoked in the pregnant rats via injecting the 1% of STZ (25 mg/kg) and then treated with the 50 mg/kg of myrtenol. The glucose level and bodyweight of animals were noted. The lipid profile, that is, total cholesterol, triglycerides, low-density lipoprotein, and high-density lipoprotein (HDL) was determined by respective kits. The lipid peroxidation and antioxidants status were examined using assay kits. The status of proinflammatory markers was investigated by assay kits. The messenger RNA (mRNA) expressions of TLR4/MyD88/NF-κB signaling proteins were studied by reverse transcription polymerase chain reaction analysis. The hepatic and pancreatic tissues were examined microscopically. Myrtenol treatment notably decreased the status of blood glucose and lipid profile and improved the HDL in the GDM rats. The status of lipid peroxidation and inflammatory markers were substantially reduced by the myrtenol and it enhanced the antioxidants status of GDM animals. Myrtenol treatment remarkably downregulated the mRNA expressions of TLR4/MyD88/NF-κB signaling proteins. The histological findings also proved the therapeutic actions of myrtenol. Altogether, the findings of this investigation unveiled the therapeutic actions of the myrtenol against the STZ-provoked GDM in rats. Myrtenol could be a promising therapeutic agent to treat GDM in the future.

Downregulating of hemB via synthetic antisense RNAs for improving 5-aminolevulinic acid production in Escherichia coli.

Aminolevulinic acid (ALA), a type of natural non-protein amino acid, is a key precursor for the biosynthesis of heme, and it has been broadly applied in medicine, agriculture. Several strategies have been applied to enhance ALA synthesis in bacteria. In the present study, we employed synthetic antisense RNAs (asRNAs) of hemB (encodes ALA dehydratase) to weaken metabolic flux of ALA to porphobilinogen (PBG), and investigated their effect on ALA accumulation. For this purpose, we designed and constructed vectors pET28a-hemA-asRNA and pRSFDuet-hemA-asRNA to simultaneously express 5-ALA synthase (ALAS, encoded by hemA) and PTasRNAs (2 inverted repeat DNA sequences sandwiched with the antisense sequence of hemB), selecting the region ranging from - 57 nt upstream to + 139 nt downstream of the start codon of hemB as a target. The qRT-PCR analysis showed that the mRNA levels of hemB were decreased above 50% of the control levels, suggesting that the anti-hemB asRNA was functioning appropriately. ALA accumulation in the hemB weakened strains were 17.6% higher than that obtained using the control strains while accumulating less PBG. These results indicated that asRNAs can be used as a tool for regulating ALA accumulation in E. coli. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-021-02733-8.

A simple transmission dynamics model for predicting the evolution of COVID-19 under control measures in China.

Epidemic forecasting provides an opportunity to predict geographic disease spread and counts when an outbreak occurs and plays a key role in preventing or controlling their adverse impact. However, conventional prediction models based on complex mathematical modelling rely on the estimation of model parameters, which yields unreliable and unsustainable results. Herein, we proposed a simple model for predicting the epidemic transmission dynamics based on nonlinear regression of the epidemic growth rate and iterative methods, which is applicable to the progression of the COVID-19 outbreak under the strict control measures of the Chinese government. Our model yields reliable and accurate results as confirmed by the available data: we predicted that the total number of infections in mainland China would be 91 253, and the maximum number of beds required for hospitalised patients would be 62 794. We inferred that the inflection point (when the growth rate turns from positive to negative) of the epidemic across China would be mid-February, and the end of the epidemic would be in late March. This model is expected to contribute to resource allocation and planning in the health sector while providing a theoretical basis for governments to respond to future global health crises or epidemics.