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Communications Biology Jul 2024The peroxisome is a versatile organelle that performs diverse metabolic functions. PEX3, a critical regulator of the peroxisome, participates in various biological...
The peroxisome is a versatile organelle that performs diverse metabolic functions. PEX3, a critical regulator of the peroxisome, participates in various biological processes associated with the peroxisome. Whether PEX3 is involved in peroxisome-related redox homeostasis and myocardial regenerative repair remains elusive. We investigate that cardiomyocyte-specific PEX3 knockout (Pex3-KO) results in an imbalance of redox homeostasis and disrupts the endogenous proliferation/development at different times and spatial locations. Using Pex3-KO mice and myocardium-targeted intervention approaches, the effects of PEX3 on myocardial regenerative repair during both physiological and pathological stages are explored. Mechanistically, lipid metabolomics reveals that PEX3 promotes myocardial regenerative repair by affecting plasmalogen metabolism. Further, we find that PEX3-regulated plasmalogen activates the AKT/GSK3β signaling pathway via the plasma membrane localization of ITGB3. Our study indicates that PEX3 may represent a novel therapeutic target for myocardial regenerative repair following injury.
Topics: Animals; Mice; Mice, Knockout; Integrin beta3; Cell Membrane; Regeneration; Myocytes, Cardiac; Male; Plasmalogens; Signal Transduction; Myocardium; Mice, Inbred C57BL; Heart Injuries; Cell Proliferation; Membrane Proteins
PubMed: 38951640
DOI: 10.1038/s42003-024-06483-0 -
Archives of Microbiology Jun 2024A Gram-stain-negative, aerobic, rod-shaped and motile strain HL-JVS1, was isolated from the gastric tract of a juvenile Pacific white shrimp. Molecular phylogenetic...
A Gram-stain-negative, aerobic, rod-shaped and motile strain HL-JVS1, was isolated from the gastric tract of a juvenile Pacific white shrimp. Molecular phylogenetic analysis based on 16S rRNA gene sequences of strain HL-JVS1 revealed its affiliation with the genus Pleionea, with close relatives including Pleionea mediterranea MOLA115 (97.5%) and Pleionea sediminis S1-5-21 (96.2%). The complete genome of strain HL-JVS1 consisted of a circular 4.4 Mb chromosome and two circular plasmids (6.6 and 35.0 kb) with a G + C content of 43.1%. The average nucleotide identity and digital DNA-DNA hybridization values between strain HL-JVS1 and the type strains of described Pleionea species were 69.7-70.4% and 18.3-18.6%, respectively. Strain HL-JVS1 grew at 10-40 °C (optimum, 30 °C) in the presence of 0.5 - 9.0% (w/v) sea salts (optimum, 2.0 - 2.5%), and at pH range of 5.5 - 10.0 (optimum, pH 6.5). The major fatty acids (> 10%) were summed feature 9 (iso-C ω9c and/or C 10-methyl) (23.3%), iso-C (14.5%), iso-C 3-OH (13.8%) and iso-C (11.0%). The polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an unidentified aminophospholipid, two unidentified aminolipids, and two unidentified lipids. The respiratory quinone was ubiquinone-8. The comprehensive phylogenetic, phylogenomic, phenotypic and chemotaxonomic results showed that strain HL-JVS1 is distinct from other Pleionea species. Hence, we propose strain HL-JVS1 as a novel species belonging to the genus Pleionea, for which the name Pleionea litopenaei sp. nov. is proposed with HL-JVS1 (= KCCM 90514 = JCM 36490) as the type strain.
Topics: Animals; Penaeidae; Phylogeny; Base Composition; RNA, Ribosomal, 16S; Fatty Acids; DNA, Bacterial; Bacterial Typing Techniques; Nucleic Acid Hybridization; Sequence Analysis, DNA; Genome, Bacterial; Planococcaceae; Gastrointestinal Tract; Phospholipids
PubMed: 38951206
DOI: 10.1007/s00203-024-04064-7 -
Archives of Microbiology Jun 2024A Gram-negative, aerobic, rod-shaped, non-motile bacterium, designated as FTW29, was isolated from surface seawater sampled in Futian district, Shenzhen, China. Growth...
A Gram-negative, aerobic, rod-shaped, non-motile bacterium, designated as FTW29, was isolated from surface seawater sampled in Futian district, Shenzhen, China. Growth of strain FTW29 was observed at 15-42 ℃ (optimum, 28-30 ℃), pH 4.0-9.0 (optimum, pH 5.5-7.5) and in the presence of 0.5-10% NaCl (optimum, 3.0% NaCl). Strain FTW29 showed 95.0-96.8% 16 S rRNA gene sequence similarity to various type strains of the genera Thioclava, Sinirhodobacter, Rhodobacter, Haematobacter and Frigidibacter of the family Paracoccaceae, and its most closely related strains were Thioclava pacifica DSM 10,166 (96.8%) and Thioclava marina 11.10-0-13 (96.7%). The phylogenomic tree constructed on the bac120 gene set showed that strain FTW29 formed a clade with the genus Thioclava, with a bootstrap value of 100%. The evolutionary distance values between FTW29 and type strains of the genus Thioclava were 0.17-0.19, which are below the recommended standard (0.21-0.23) for defining a novel genus in the family Paracoccaceae. In strain FTW29, the major fatty acids identified were summed feature 8 (Cω7c) and C and the predominant respiratory quinones were ubiquinone-10 and ubiquinone-9. The composition of polar lipids in strain FTW29 included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, an unidentified phospholipid, an unidentified aminolipid, two unidentified glycolipids and an unidentified lipid. The genome of strain FTW29 comprised one circle chromosome and six plasmids, with a G + C content of 61.4%. The average nucleotide identity, average amino acid identity, and digital DNA-DNA hybridization values between strain FTW29 and seven type strains of the genus Thioclava were 76.6-78.4%, 53.2-56.4% and 19.3-20.4%, respectively. Altogether, the phenotypic, phylogenetic and chemotaxonomic evidence illustrated in this study suggested that strain FTW29 represents a novel species of the genus Thioclava, with the proposed name Thioclava litoralis sp. nov. The type strain is FTW29 (= KCTC 82,841 = MCCC 1K08523).
Topics: Seawater; Phylogeny; RNA, Ribosomal, 16S; Fatty Acids; DNA, Bacterial; Base Composition; China; Bacterial Typing Techniques; Phospholipids; Alphaproteobacteria; Sequence Analysis, DNA; Ubiquinone; Nucleic Acid Hybridization
PubMed: 38951168
DOI: 10.1007/s00203-024-04057-6 -
Communications Biology Jun 2024Acute immune responses with excess production of cytokines, lipid/chemical mediators, or coagulation factors, often result in lethal damage. In addition, the innate...
Acute immune responses with excess production of cytokines, lipid/chemical mediators, or coagulation factors, often result in lethal damage. In addition, the innate immune system utilizes multiple types of receptors that recognize neurotransmitters as well as pathogen-associated molecular patterns, making immune responses complex and clinically unpredictable. We here report an innate immune and adrenergic link inducing lethal levels of platelet-activating factor. Injecting mice with toll-like receptor (TLR) 4 ligand lipopolysaccharide (LPS), cell wall N-glycans of Candida albicans, and the α-adrenergic receptor (α-AR) agonist medetomidine induces lethal damage. Knocking out the C-type lectin Dectin-2 prevents the lethal damage. In spleen, large amounts of platelet-activating factor (PAF) are detected, and knocking out lysophospholipid acyltransferase 9 (LPLAT9/LPCAT2), which encodes an enzyme that converts inactive lyso-PAF to active PAF, protects mice from the lethal damage. These results reveal a linkage/crosstalk between the nervous and the immune system, possibly inducing lethal levels of PAF.
Topics: Animals; Platelet Activating Factor; Mice; Mice, Knockout; Mice, Inbred C57BL; Lipopolysaccharides; Candida albicans; Immunity, Innate; Male; 1-Acylglycerophosphocholine O-Acyltransferase; Toll-Like Receptor 4; Adrenergic alpha-2 Receptor Agonists
PubMed: 38951147
DOI: 10.1038/s42003-024-06498-7 -
Journal of Thrombosis and Haemostasis :... Jun 2024; Factor (F)V is pivotal in both procoagulant and anticoagulant mechanisms. The present report describes a novel F5 mutation in a FV-deficient patient (FV:C 6 IU/dL,...
BACKGROUND
; Factor (F)V is pivotal in both procoagulant and anticoagulant mechanisms. The present report describes a novel F5 mutation in a FV-deficient patient (FV:C 6 IU/dL, FV:Ag 32 IU/dL), complicated with recurrent deep vein thrombosis. The patient demonstrated activated protein C resistance (APCR) with compound heterozygous mutations consisting of FV-Y1961C (FV) and FV-1982_1983del. AIM;: To clarify thrombotic mechanisms associated with this FV abnormality.
METHODS AND RESULTS
Levels of FV-1982_1983del were below the detection sensitivity in our expression experiments using HEK293T cells, and analyses were targeted, therefore on the FV-Y1961C mutation. APTT-based clotting assays demonstrated that FV-Y1961C exhibited APCR, and that the reduced APC susceptibility in FVa-Y1961C resulted in a marked depression of APC-catalyzed inactivation with delayed cleavage at Arg and little cleavage at Arg with or without protein (P)S. The APC cofactor activity of FV-Y1961C in APC-catalyzed FVIIIa inactivation promoted by Arg cleavage in FVIII was impaired. The binding affinity of FVa-Y1961C to phospholipid membranes was reduced in reactions involving APC/PS-catalyzed inactivation and in prothrombinase activity. Furthermore, the addition of FVa-Y1961C to plasma failed to inhibit tissue factor (TF)-induced procoagulant function. These characteristics were similar to those of FV-W1920R (FV) and FV-A2086D (FV).
CONCLUSIONS
; We identified a compound heterozygous. FV-Y1961C mutation in the C1 domain representing a novel FV mutation (FV) resulting in not only APCR due to impaired FVa susceptibility and FV cofactor activity for APC function, but impaired inhibition of TF-induced procoagulant function. These defects in anticoagulant function associated with FV in FV-Y1961C contributed to a prothrombotic state.
PubMed: 38950780
DOI: 10.1016/j.jtha.2024.06.014 -
Microbes and Infection Jun 2024Trypanosoma cruzi, the etiological agent of Chagas' disease, can infect both phagocytic and non-phagocytic cells. T. cruzi gp82 and gp90 are cell surface proteins...
Trypanosoma cruzi, the etiological agent of Chagas' disease, can infect both phagocytic and non-phagocytic cells. T. cruzi gp82 and gp90 are cell surface proteins belonging to Group II trans-sialidases known to be involved in host cell binding and invasion. Phosphatidylinositol kinases (PIK) are lipid kinases that phosphorylate phospholipids in their substrates or in themselves, regulating important cellular functions such as metabolism, cell cycle and survival. Vps34, a class III PIK, regulates autophagy, trimeric G-protein signaling, and the mTOR (mammalian Target of Rapamycin) nutrient-sensing pathway. The mammalian autophagy gene Beclin1 interacts to Vps34 forming Beclin 1-Vps34 complexes involved in autophagy and protein sorting. In T. cruzi epimastigotes, (a non-infective replicative form), TcVps34 has been related to morphological and functional changes associated to vesicular trafficking, osmoregulation and receptor-mediated endocytosis. We aimed to characterize the role of TcVps34 during invasion of HeLa cells by metacyclic (MT) forms. MTs overexpressing TcVps34 showed lower invasion rates compared to controls, whilst exhibiting a significant decrease in gp82 expression in the parasite surface. In addition, we showed that T. cruzi Beclin (TcBeclin1) colocalizes with TcVps34 in epimastigotes, thus suggesting the formation of complexes that may play conserved cellular roles already described for other eukaryotes.
PubMed: 38950642
DOI: 10.1016/j.micinf.2024.105385 -
Small (Weinheim An Der Bergstrasse,... Jul 2024Intracellular reactive oxygen species (ROS) in steatotic cells pose a problem due to their potential to cause oxidative stress and cellular damage. Delivering engineered...
Intracellular reactive oxygen species (ROS) in steatotic cells pose a problem due to their potential to cause oxidative stress and cellular damage. Delivering engineered phospholipids to intracellular lipid droplets in steatotic hepatic cells, using the cell's inherent intracellular lipid transport mechanisms are investigated. Initially, it is shown that tail-labeled fluorescent lipids assembled into liposomes are able to be transported to intracellular lipid droplets in steatotic HepG2 cells and HHL-5 cells. Further, an antioxidant, an EUK salen-manganese derivative, which has superoxide dismutase-like and catalase-like activity, is covalently conjugated to the tail of a phospholipid and formulated as liposomes for administration. Steatotic HepG2 cells and HHL-5 cells incubated with these antioxidant liposomes have lower intracellular ROS levels compared to untreated controls and non-covalently formulated antioxidants. This first proof-of-concept study illustrates an alternative strategy to equip native organelles in mammalian cells with engineered enzyme activity.
PubMed: 38949047
DOI: 10.1002/smll.202400816 -
Several common methods of making vesicles (except an emulsion method) capture intended lipid ratios.BioRxiv : the Preprint Server For... Jun 2024Researchers choose different methods of making giant unilamellar vesicles in order to satisfy different constraints of their experimental designs. A challenge of using a...
UNLABELLED
Researchers choose different methods of making giant unilamellar vesicles in order to satisfy different constraints of their experimental designs. A challenge of using a variety of methods is that each may produce vesicles of different lipid compositions, even if all vesicles are made from a common stock mixture. Here, we use mass spectrometry to investigate ratios of lipids in vesicles made by five common methods: electroformation on indium tin oxide slides, electroformation on platinum wires, gentle hydration, emulsion transfer, and extrusion. We made vesicles from either 5-component or binary mixtures of lipids chosen to span a wide range of physical properties: di(18:1)PC, di(16:0)PC, di(18:1)PG, di(12:0)PE, and cholesterol. For a mixture of all five of these lipids, ITO electroformation, Pt electroformation, gentle hydration, and extrusion methods result in only minor shifts (≤ 5 mol%) in lipid ratios of vesicles relative to a common stock solution. In contrast, emulsion transfer results in ∼80% less cholesterol than expected from the stock solution, which is counterbalanced by a surprising overabundance of saturated PC-lipid relative to all other phospholipids. Experiments using binary mixtures of some of the lipids largely support results from the 5-component mixture. Exact values of lipid ratios variations likely depend on the details of each method, so a broader conclusion is that experiments that increment lipid ratios in small steps will be highly sensitive to the method of lipid formation and to sample-to-sample variations, which are low (roughly ±2 mol% in the 5-component mixture and either scale proportionally with increasing mole fraction or remain low). Experiments that increment lipid ratios in larger steps or that seek to explain general trends or new phenomena will be less sensitive to the method used.
SIGNIFICANCE STATEMENT
Small changes to the amounts and types of lipids in membranes can drastically affect the membrane's behavior. Unfortunately, it is unknown whether (or to what extent) different methods of making vesicles alter the ratios of lipids in membranes, even when identical stock solutions are used. This presents challenges for researchers when comparing data with colleagues who use different methods. Here, we measure ratios of lipid types in vesicle membranes produced by five methods. We assess each method's reproducibility and compare resulting vesicle compositions across methods. In doing so, we provide a quantitative basis that the scientific community can use to estimate whether differences between their results can be simply attributed to differences between methods or to sample-to-sample variations.
PubMed: 38948736
DOI: 10.1101/2024.02.21.581444 -
BioRxiv : the Preprint Server For... Jun 2024Mitochondria are central to cellular metabolism; hence, their dysfunction contributes to a wide array of human diseases including cancer, cardiopathy, neurodegeneration,...
Mitochondria are central to cellular metabolism; hence, their dysfunction contributes to a wide array of human diseases including cancer, cardiopathy, neurodegeneration, and heritable pathologies such as Barth syndrome. Cardiolipin, the signature phospholipid of the mitochondrion promotes proper cristae morphology, bioenergetic functions, and directly affects metabolic reactions carried out in mitochondrial membranes. To match tissue-specific metabolic demands, cardiolipin typically undergoes an acyl tail remodeling process with the final step carried out by the phospholipid-lysophospholipid transacylase tafazzin. Mutations in the gene are the primary cause of Barth syndrome. Here, we investigated how defects in cardiolipin biosynthesis and remodeling impact metabolic flux through the tricarboxylic acid cycle and associated pathways in yeast. Nuclear magnetic resonance was used to monitor in real-time the metabolic fate of C -pyruvate in isolated mitochondria from three isogenic yeast strains. We compared mitochondria from a wild-type strain to mitochondria from a Δ strain that lacks tafazzin and contains lower amounts of unremodeled cardiolipin, and mitochondria from a Δ strain that lacks cardiolipin synthase and cannot synthesize cardiolipin. We found that the C-label from the pyruvate substrate was distributed through about twelve metabolites. Several of the identified metabolites were specific to yeast pathways, including branched chain amino acids and fusel alcohol synthesis. Most metabolites showed similar kinetics amongst the different strains but mevalonate and α-ketoglutarate, as well as the NAD+/NADH couple measured in separate nuclear magnetic resonance experiments, showed pronounced differences. Taken together, the results show that cardiolipin remodeling influences pyruvate metabolism, tricarboxylic acid cycle flux, and the levels of mitochondrial nucleotides.
PubMed: 38948727
DOI: 10.1101/2024.06.18.599628 -
Journal of Family Medicine and Primary... May 2024Corona virus disease (COVID-19) initially appeared to be an exclusively respiratory ailment. While that is true in a vast majority of the cases, its evolution and later...
Corona virus disease (COVID-19) initially appeared to be an exclusively respiratory ailment. While that is true in a vast majority of the cases, its evolution and later evidence have shown that it can afflict virtually any organ system in the human body after first gaining entry through the respiratory tract. The COVID-19 vaccines were one of the turning points in the campaign to control the COVID-19 pandemic. However, after their extensive use all over the world, it has emerged that they can cause some dangerous collateral damage. We, herein, report the case of a 58-year-old woman who presented to us with signs and symptoms of acute intestinal obstruction 4 months after receiving her first dose of Covishield vaccination for COVID-19. Her blood tests showed a high D-dimer and normal platelet count. She was previously admitted to the hospital with an acute abdomen 3 months back. A contrast-enhanced computed tomography (CECT) scan of the abdomen done then had revealed thrombi in the aorta and inferior mesenteric and splenic arteries. She was started on low-molecular-weight heparin and discharged on tablet Warfarin after clinical improvement. CECT abdomen done during her present admission revealed a proximal small bowel stricture with dilated proximal and collapsed distal loops. She underwent a laparoscopic jejuno-ileal resection anastomosis. During the post-operative period, a repeat CECT abdomen done to evaluate multiple episodes of vomiting revealed pulmonary embolism in the lower chest cuts. A venous Doppler revealed extensive deep venous thrombosis of the left lower limb. A thrombophilia profile diagnosed anti-phospholipid antibody syndrome, an exacerbation of which was likely precipitated by the COVID-19 vaccine.
PubMed: 38948557
DOI: 10.4103/jfmpc.jfmpc_1006_23