Refining taxonomic identification of microalgae through molecular and genetic evolution: a case study of Prorocentrum lima and Prorocentrum arenarium.

Species delimitation based on lineage definition has become increasingly popular. However, these methods have been limited, especially for species that lack genomic data and are morphologically similar. The trickiest part for the species identification is that the interspecific and intraspecific boundaries are vague. Taking Prorocentrum (Dinophyta) as an example, analysis of cell morphology, growth, and toxin synthesis in both species of P. lima and P. arenarium does not provide a reliable basis for species delineation. However, through phylogenetic and genetic distance analyses of their ITS and LSU sequences, establishment of evolutionary tree based on orthologous gene sequences, and combining the results of automatic barcode gap discovery and Poisson tree processes models, it was sustained that P. arenarium does not belong to the P. lima complex and should be considered as an independent species. Interspecies genetic evolution analysis revealed that P. lima and P. arenarium may contribute to evolutionary direction that favors combating reverse environmental factors. In P. lima, viral invasion may be one of the reasons for its large genome size. In the study, P. lima complex has been selected as an example to enhance the taxonomic identification of microalgae through molecular and genetic evolution, offering valuable insights into refining taxonomic identification and promoting microbial biodiversity research in other species.IMPORTANCEMicroalgae, especially the species known as Prorocentrum, have received significant attention due to their ability to trigger harmful algal blooms and produce toxins. However, the boundaries between species and within species are ambiguous. Clear and comprehensive species delineation indicates that Prorocentrum arenarium should be considered as an independent species, separate from the Prorocentrum lima complex. Improving the classification and identification of microalgae through molecular and genetic evolution will provide reference points for other cryptic species. Prorocentrum occupy multiple ecological niches in marine environments, and studying their evolutionary direction contributes to understanding their ecological adaptations and community succession.

Advanced glycation end products induce senescence of atrial myocytes and increase susceptibility of atrial fibrillation in diabetic mice.

Diabetes mellitus (DM) is a common chronic metabolic disease caused by significant accumulation of advanced glycation end products (AGEs). Atrial fibrillation (AF) is a common cardiovascular complication of DM. Here, we aim to clarify the role and mechanism of atrial myocyte senescence in the susceptibility of AF in diabetes. Rapid transesophageal atrial pacing was used to monitor the susceptibility of mice to AF. Whole-cell patch-clamp was employed to record the action potential (AP) and ion channels in single HL-1 cell and mouse atrial myocytes. More importantly, anti-RAGE antibody and RAGE-siRNA AAV9 were used to investigate the relationship among diabetes, aging, and AF. The results showed that elevated levels of p16 and retinoblastoma (Rb) protein in the atrium were associated with increased susceptibility to AF in diabetic mice. Mechanistically, AGEs increased p16/Rb protein expression and the number of SA-ß-gal-positive cells, prolonged the action potential duration (APD), reduced protein levels of Cav1.2, Kv1.5, and current density of ICa,L , IKur in HL-1 cells. Anti-RAGE antibody or RAGE-siRNA AAV9 reversed these effects in vitro and in vivo, respectively. Furthermore, downregulating p16 or Rb by siRNA prevented AGEs-mediated reduction of Cav1.2 and Kv1.5 proteins expression. In conclusion, AGEs accelerated atrial electrical remodeling and cellular senescence, contributing to increased AF susceptibility by activating the p16/Rb pathway. Inhibition of RAGE or the p16/Rb pathway may be a potential therapeutic target for AF in diabetes.

Effect of BTP2 on agonist-induced vasoconstriction in the mouse aorta in vitro.

BTP2 is a potent inhibitor of store-operated Ca2+ entry (SOCE), which plays a vital role in vasoconstriction. However, the direct effect of BTP2 on the contractile response remains unclear. Here, we investigated the effects and mechanisms of action of BTP2 in the mouse aorta. Isometric tension was measured using a Multi Myograph System with two stainless steel wires. Ca2+ transient was recorded by confocal laser scanning microscope. The results showed that BTP2 markedly suppressed vasoconstriction mediated by SOCE and Ca2+ influx mediated by SOCE. The cumulative concentration of BTP2 had no effect on the baseline of mouse aortic rings, whereas it increased vasoconstriction stimulated by 3 µmol/L Phenylephrine. BTP2 (1 µmol/L) significantly increased vasoconstriction induced by 3 µmol/L Phe or cumulative concentration. BTP2 also promoted noradrenaline-induced aortic contraction. However, Phe- and noradrenaline-induced contraction was not affected by 0.3 or 3 µmol/L BTP2, and BTP2 at 10 µmol/L significantly suppressed aortic contraction. BTP2 inhibited 5-HT-evoked contraction in a concentration-dependent manner. BTP2 at higher concentrations (>3 µmol/L) inhibited CaCl2 -induced and 60 mmol/L K+ -induced contraction with progressive reduction of maximal contraction in a concentration-dependent manner. These results suggest that 1 µmol/L BTP2 increases contraction evoked by α1 adrenoreceptor activation. BTP2 at higher concentrations may inhibit Cav1.2 channels.

High glucose induces Drp1-mediated mitochondrial fission via the Orai1 calcium channel to participate in diabetic cardiomyocyte hypertrophy.

Mitochondrial dysfunction and impaired Ca2+ handling are involved in the development of diabetic cardiomyopathy (DCM). Dynamic relative protein 1 (Drp1) regulates mitochondrial fission by changing its level of phosphorylation, and the Orai1 (Ca2+ release-activated calcium channel protein 1) calcium channel is important for the increase in Ca2+ entry into cardiomyocytes. We aimed to explore the mechanism of Drp1 and Orai1 in cardiomyocyte hypertrophy caused by high glucose (HG). We found that Zucker diabetic fat rats induced by administration of a high-fat diet develop cardiac hypertrophy and impaired cardiac function, accompanied by the activation of mitochondrial dynamics and calcium handling pathway-related proteins. Moreover, HG induces cardiomyocyte hypertrophy, accompanied by abnormal mitochondrial morphology and function, and increased Orai1-mediated Ca2+ influx. Mechanistically, the Drp1 inhibitor mitochondrial division inhibitor 1 (Mdivi-1) prevents cardiomyocyte hypertrophy induced by HG by reducing phosphorylation of Drp1 at serine 616 (S616) and increasing phosphorylation at S637. Inhibition of Orai1 with single guide RNA (sgOrai1) or an inhibitor (BTP2) not only suppressed Drp1 activity and calmodulin-binding catalytic subunit A (CnA) and phosphorylated-extracellular signal-regulated kinase (p-ERK1/2) expression but also alleviated mitochondrial dysfunction and cardiomyocyte hypertrophy caused by HG. In addition, the CnA inhibitor cyclosporin A and p-ERK1/2 inhibitor U0126 improved HG-induced cardiomyocyte hypertrophy by promoting and inhibiting phosphorylation of Drp1 at S637 and S616, respectively. In summary, we identified Drp1 as a downstream target of Orai1-mediated Ca2+ entry, via activation by p-ERK1/2-mediated phosphorylation at S616 or CnA-mediated dephosphorylation at S637 in DCM. Thus, the Orai1-Drp1 axis is a novel target for treating DCM.

The decreased expression of IKBKE in systemic lupus erythematosus.

OBJECTIVE: The IKBKE has been proven to be associated with systemic lupus erythematosus (SLE) in a genome-wide association study (GWAS) conducted by our group. The objective of the recent study is to investigate the contribution of IKBKE functional variants (rs2297550) to SLE. METHODS: We detected the regulatory effect of rs2297550 on IKBKE expression by expression quantitative trait loci (eQTL) study. Then, we investigated the differences of IKBKE mRNA expression levels in peripheral blood mononuclear cells (PBMCs) between 135 SLE patients and 130 healthy controls using quantitative real-time PCR (qRT-PCR). We further analyzed the association of SLE clinical characteristics with IKBKE mRNA expression and rs2297550 polymorphisms. RESULTS: The results of eQTL indicated the genotype "GG" of single-nucleotide polymorphism (SNP) rs2297550 was associated with lower expression levels of IKBKE (P = 0.022) in normal controls. Compared with the healthy control group, the expression levels of IKBKE mRNA in patients with SLE were significantly decreased (P = 2.32 × 10-12). In clinical characteristics, we found that IKBKE mRNA expression levels were associated with vasculitis (P = 0.015) and increased C-reactive protein (CRP) (P = 0.021) in SLE patients. CONCLUSION: In this study, we not only detected that the variant rs2297550 of IKBKE may be closely related to SLE, but also proposed functional hypotheses for the association signals. Key Points • The rs2297550 is located in a region with transcriptional regulatory function and may regulate the expression of IKBKE via these regulatory elements. • The genotype "GG" of SNP rs2297550 was associated with lower expression levels of IKBKE. • The expression of IKBKE mRNA was decreased in SLE patients compared with healthy controls. • IKBKE contributes to the clinical characteristics of SLE.

Bayesian Network Modelling of ATC Complexity Metrics for Future SESAR Demand and Capacity Balance Solutions.

Demand & Capacity Management solutions are key SESAR (Single European Sky ATM Research) research projects to adapt future airspace to the expected high air traffic growth in a Trajectory Based Operations (TBO) environment. These solutions rely on processes, methods and metrics regarding the complexity assessment of traffic flows. However, current complexity methodologies and metrics do not properly take into account the impact of trajectories' uncertainty to the quality of complexity predictions of air traffic demand. This paper proposes the development of several Bayesian network (BN) models to identify the impacts of TBO uncertainties to the quality of the predictions of complexity of air traffic demand for two particular Demand Capacity Balance (DCB) solutions developed by SESAR 2020, i.e., Dynamic Airspace Configuration (DAC) and Flight Centric Air Traffic Control (FCA). In total, seven BN models are elicited covering each concept at different time horizons. The models allow evaluating the influence of the "complexity generators" in the "complexity metrics". Moreover, when the required level for the uncertainty of complexity is set, the networks allow identifying by how much uncertainty of the input variables should improve.

Hsp90 inhibitor AT-533 blocks HSV-1 nuclear egress and assembly.

Heat shock protein 90 (Hsp90) has been identified as an essential host factor for the infection and replication of several viruses, including HSV-1. Recent works have clearly shown that Hsp90 plays a role in the early stages of HSV-1 infection, including nuclear import and DNA replication. However, the role of Hsp90 in the late stages of HSV-1 infection remains unclear. In this study, we found that Hsp90 was up-regulated during late viral infection. Treatment with the Hsp90 inhibitor AT-533 significantly decreased the intracellular and extracellular virus titers, and strongly inhibited nucleocapsid egress from the nucleus. More detailed studies revealed that AT-533 inhibited the nuclear egress of the viral nucleocapsid by suppressing the expression and translocation of nuclear-associated proteins pUL31 and pUL34. In addition, we found that AT-533 hindered the assembly of virus particles possibly though affecting the localization of glycoproteins in the endoplasmic reticulum and Golgi apparatus. These results thus invoke a new role for Hsp90 in the nucleocapsid egress and viral maturation of HSV-1, and further promote the development of Hsp90 inhibitors as potential anti-HSV-1 drugs.

High-efficiency promoter-driven coordinated regulation of multiple metabolic nodes elevates lipid accumulation in the model microalga Phaeodactylum tricornutum.

BACKGROUND: Microalgal metabolic engineering holds great promise for the overproduction of a wide range of commercial bioproducts. It demands simultaneous manipulation of multiple metabolic nodes. However, high-efficiency promoters have been lacking. RESULTS: Here we report a strong constitutive promoter Pt211 in expressing multiple target genes in oleaginous microalga Phaeodactylum tricornutum. Pt211 was revealed to contain significant cis-acting elements. GUS reporter and principal genes glycerol-3-phosphate acyltransferase (GPAT) and diacylglycerol acyltransferase 2 (DGAT2) involved in triacylglycerol biosynthesis were tested under driven of Pt211 in P. tricornutum. GUS staining and qPCR analysis showed strong GUS expression. DGAT2 and GPAT linked with a designed 2A sequence exhibited higher transcript abundances than WT, while algal growth and photosynthesis were not impaired. CONCLUSION: The total lipid content increased notably by 2.6-fold compared to WT and reached up to 57.5% (dry cell weight). Overall, our findings report a strong promoter and a strategy for coordinated manipulation of complex metabolic pathways.

Description of Pella sichuanensis sp. n. (Coleoptera: Staphylinidae: Aleocharinae) from Micang Mountain, Sichuan, China.

Pella sichuanensis Zheng & Zhao, sp. n. of the P. cognata group is described, illustrated, and distinguished from similar congeners.

Review of nitidotachinus campbell (staphylinidae, tachyporinae) from mainland china.

The genus Nitidotachinus Campbell of Mainland China is reviewed with descriptions of five new species: Nitidotachinusanhuiensis sp. n. (Anhui), Nitidotachinusbini sp. n. (Zhejiang), Nitidotachinusbrunneus sp. n. (Zhejiang), Nitidotachinuscapillosus sp. n. (Zhejiang), and Nitidotachinusxiangi sp. n. (Hubei). Nitidotachinusexcellensconcolor Schülke is synonymized with Nitidotachinusexcellens syn. n. All treated species are described with their major diagnostic characters illustrated. An identification key to the species is given.

A new species of genus Tetrasticta Kraatz (Coleoptera, Staphylinidae, Aleocharinae) from Xishuangbanna, Southwest China.

Tetrasticta bobbii Zheng & Zhao, sp. n., collected in Nangongshan, Xishuangbanna, Yunnan, is described and illustrated.