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International Journal of Systematic and... Jul 2024Two novel strain pairs (HM61/HM23 and S-34/S-58) were isolated from soil and the faeces of Tibetan antelope () collected at the Qinghai-Tibet Plateau of PR China. All...
Two novel strain pairs (HM61/HM23 and S-34/S-58) were isolated from soil and the faeces of Tibetan antelope () collected at the Qinghai-Tibet Plateau of PR China. All four new isolates were aerobic, non-motile, Gram-stain-positive, catalase-positive, oxidase-negative, and short rod-shaped bacteria. The results of phylogenetic analysis based on the full-length 16S rRNA genes and 283 core genomic genes indicated that the four strains were separated into two independent branches belonging to the genus . Strains HM61 and HM23 were most closely related to THG T63 (98.58 and 98.65 % 16S rRNA gene sequence similarity). Strains S-34 and S-58 were most closely related to MMS20-HV4-12 (98.89 and 98.89 % 16S rRNA gene sequence similarity). The G+C contents of the genomic DNA of strains HM61 and S-34 were 70.6 and 72.5 mol%, respectively. Strains HM61, S-34 and the type strains of closely related species in the analysis had average nucleotide identity values of 75.4-90.5 % as well as digital DNA-DNA hybridization values between 20.1 and 40.8 %, which clearly indicated that the four isolates represent two novel species within the genus . The chemotaxonomic characteristics of strains HM61 and S-34 were consistent with the genus . The major fatty acids of all four strains were -C, C 8 or C 9. For strains HM61 and S-34, MK-8(H) was the predominant respiratory quinone, ll-2,6-diaminopimelic acid was the diagnostic diamino acid in the cell-wall peptidoglycan, and the polar lipids profiles were composed of diphosphatidylglycerol and phosphatidylglycerol. Based on phylogenetic, phenotypic, and chemotaxonomic data, we propose that strains HM61 and S-34 represent two novel species of the genus , respectively, with the names sp. nov. and sp. nov. The type strains are HM61 (=GDMCC 4.343=JCM 36399) and S-34 (=CGMCC 4.7664=JCM 33792).
Topics: Phylogeny; RNA, Ribosomal, 16S; Soil Microbiology; Base Composition; Tibet; Fatty Acids; DNA, Bacterial; Bacterial Typing Techniques; Sequence Analysis, DNA; Feces; Antelopes; Animals; Nucleic Acid Hybridization; China; Actinomycetales; Peptidoglycan; Phospholipids
PubMed: 38953888
DOI: 10.1099/ijsem.0.006437 -
Journal of Bacteriology Jul 2024It is well established that can incorporate exogenous straight-chain unsaturated fatty acids (SCUFAs) into membrane phospho- and glyco-lipids from various sources in...
UNLABELLED
It is well established that can incorporate exogenous straight-chain unsaturated fatty acids (SCUFAs) into membrane phospho- and glyco-lipids from various sources in supplemented culture media and when growing during infection. Given the enhancement of membrane fluidity when oleic acid (C18:1Δ9) is incorporated into lipids, we were prompted to examine the effect of medium supplementation with C18:1Δ9 on growth at low temperatures. C18:1Δ9 supported the growth of a cold-sensitive, branched-chain fatty acid (BCFA)-deficient mutant at 12°C. Interestingly, we found similar results in the BCFA-sufficient parental strain, supported by the fact that the incorporation of C18:1Δ9 into the membrane increased membrane fluidity in both strains. We show that the incorporation of C18:1Δ9 and its elongation product C20:1Δ11 into membrane lipids was required for growth stimulation and relied on a functional FakAB incorporation system. Lipidomics analysis of the phosphatidylglycerol and diglycosyldiacylglycerol lipid classes revealed major impacts of C18:1Δ9 and temperature on lipid species. Growth at 12°C in the presence of C18:1Δ9 also led to increased production of the carotenoid pigment staphyloxanthin. The enhancement of growth by C18:1Δ9 is an example of homeoviscous adaptation to low temperatures utilizing an exogenous fatty acid. This may be significant in the growth of at low temperatures in foods that commonly contain C18:1Δ9 and other SCUFAs in various forms.
IMPORTANCE
We show that can use its known ability to incorporate exogenous fatty acids to enhance its growth at low temperatures. Individual species of phosphatidylglycerols and diglycosyldiacylglycerols bearing one or two degrees of unsaturation derived from the incorporation of C18:1Δ9 at 12°C are described for the first time. In addition, enhanced production of the carotenoid staphyloxanthin occurs at low temperatures. The studies describe a biochemical reality underlying membrane biophysics. This is an example of homeoviscous adaptation to low temperatures utilizing exogenous fatty acids over the regulation of the biosynthesis of endogenous fatty acids. The studies have likely relevance to food safety in that unsaturated fatty acids may enhance the growth of in the food environment.
PubMed: 38953643
DOI: 10.1128/jb.00187-24 -
Chemistry, An Asian Journal Jul 2024Dicarboxylate metallosurfactants (AASM), synthesized by mixing N-dodecyl aminomalonate, -aspartate and -glutamate with CaCl2, MnCl2 and CdCl2, were characterized by XRD,...
Dicarboxylate metallosurfactants (AASM), synthesized by mixing N-dodecyl aminomalonate, -aspartate and -glutamate with CaCl2, MnCl2 and CdCl2, were characterized by XRD, FTIR, and NMR spectroscopy. Layered structures, formed by metallosurfactants, were evidenced from differential scanning calorimetry and thermogravimetric analyses. Solvent-spread monolayer of AASM in combination with soyphosphatidylcholine (SPC) and cholesterol (CHOL) were studied using Langmuir surface balance. With increasing mole fraction of AASM mean molecular area increased and passed through maxima at ~60 mol% of AASMs, indicating molecular packing reorganization. Systems with 20 and 60 mol% AASM exhibited positive deviations from ideal behavior signifying repulsive interaction between the AASM and SPC, while synergistic interactions were established from the negative deviation at other combinations. Dynamic surface elasticity increased with increasing surface pressure signifying formation of rigid monolayer. Transition of monolayer from gaseous to liquid expanded to liquid condensed state was established by Brewster angle microscopic studies. Stability of the hybrid vesicles, formed by AASM+SPC+CHOL, was established by monitoring their size, zeta potential and polydispersity index values over 100 days. Size and spherical morphology of hybrid vesicles were confirmed by transmission electron microscopic studies. Biocompatibility of the hybrid vesicles were established by cytotoxicity studies revealing their possible applications in drug delivery and imaging.
PubMed: 38953124
DOI: 10.1002/asia.202400284 -
Frontiers in Pharmacology 2024Ezetimibe, which lowers cholesterol by blocking the intestinal cholesterol transporter Niemann-Pick C1 like 1, is reported to reduce hepatic steatosis in humans and...
BACKGROUND
Ezetimibe, which lowers cholesterol by blocking the intestinal cholesterol transporter Niemann-Pick C1 like 1, is reported to reduce hepatic steatosis in humans and animals. Here, we demonstrate the changes in hepatic metabolites and lipids and explain the underlying mechanism of ezetimibe in hepatic steatosis.
METHODS
We fed Otsuka Long-Evans Tokushima Fatty (OLETF) rats a high-fat diet (60 kcal % fat) with or vehicle (control) or ezetimibe (10 mg kg) via stomach gavage for 12 weeks and performed comprehensive metabolomic and lipidomic profiling of liver tissue. We used rat liver tissues, HepG2 hepatoma cell lines, and siRNA to explore the underlying mechanism.
RESULTS
In OLETF rats on a high-fat diet, ezetimibe showed improvements in metabolic parameters and reduction in hepatic fat accumulation. The comprehensive metabolomic and lipidomic profiling revealed significant changes in phospholipids, particularly phosphatidylcholines (PC), and alterations in the fatty acyl-chain composition in hepatic PCs. Further analyses involving gene expression and triglyceride assessments in rat liver tissues, HepG2 hepatoma cell lines, and siRNA experiments unveiled that ezetimibe's mechanism involves the upregulation of key phospholipid biosynthesis genes, CTP:phosphocholine cytidylyltransferase alpha and phosphatidylethanolamine N-methyl-transferase, and the phospholipid remodeling gene lysophosphatidylcholine acyltransferase 3.
CONCLUSION
This study demonstrate that ezetimibe improves metabolic parameters and reduces hepatic fat accumulation by influencing the composition and levels of phospholipids, specifically phosphatidylcholines, and by upregulating genes related to phospholipid biosynthesis and remodeling. These findings provide valuable insights into the molecular pathways through which ezetimibe mitigates hepatic fat accumulation, emphasizing the role of phospholipid metabolism.
PubMed: 38953111
DOI: 10.3389/fphar.2024.1406493 -
Frontiers in Pharmacology 2024Polygonum multiflorum Thunb. (PM), a kind of perennial plant, belongs to the genus of the family polygonaceae.The dry root of PM (also called Heshouwu), is a... (Review)
Review
BACKGROUND
Polygonum multiflorum Thunb. (PM), a kind of perennial plant, belongs to the genus of the family polygonaceae.The dry root of PM (also called Heshouwu), is a traditional Chinese medicine, which has a series of functions and is widely used in clinic for hair lossing, aging, and insomnia. While, PM also has some toxicity, its clinical drug safety has been concerned. In this paper, the chemical components, toxic mechanisms and detoxification strategies of PM were reviewed in order to provide evidence for its clinical application.
MATERIALS AND METHODS
We conducted a systematic review of published literature of PM, including English and Chinese databases, such as PubMed, Web of Science, CNKI, and Wanfang.
RESULTS
PM contains a variety of chemical compounds, including stilbenes, quinones, flavonoids, phospholipids, and has many pharmacological activities such as anti-aging, wound healing, antioxidant, and anti-inflammatory properties. The PE has certain therapeutic effect, and it has certain toxicity like hepatotoxicity, nephrotoxicity, and embryotoxicity at the same time, but.these toxic effects could be effectively reduced by processing and compatibility.
CONCLUSION
It is necessary to further explore the pharmacological and toxicological mechanisms of the main active compounds of PE.This article provides scientific basis for the safe clinical application of PM.
PubMed: 38953108
DOI: 10.3389/fphar.2024.1427019 -
RSC Advances Jun 2024Nanoscale covalent organic frameworks (NCOFs) as emerging drug-delivery nanocarriers have received much attention in biomedicine in recent years. However, there are few...
Nanoscale covalent organic frameworks (NCOFs) as emerging drug-delivery nanocarriers have received much attention in biomedicine in recent years. However, there are few reports on the application of pH-responsive NCOFs for drug delivery nanosystems. In this work, hydrazone-decorated NCOFs as pH-triggered molecular switches are designed for efficient cancer therapy. These functionalized NCOFs with hydrazone groups on the channel walls (named NCOFs-NHNH) are obtained a post-synthetic modification strategy. Subsequently, the anticancer drug doxorubicin (DOX) as the model molecule is loaded through covalent linkage to yield NCOFs-NN-DOX. Finally, soybean phospholipid (SP) is coated on the surface of HNTs-NN-DOX, named NCOFs-NN-DOX@SP, to further enhance the dispersibility, stability and biocompatibility of HNTs in physiological solution. NCOFs-NN-DOX@SP showed an excellent and intelligent sustained-release effect with an almost sixfold increase at pH = 5.2 than at pH = 7.4. cell toxicity and imaging assays of NCOFs-NN-DOX@SP exhibited an enhanced therapeutic effect on Lewis lung carcinoma (LLC) cells, demonstrating that the fabricated NCOFs have a great potential in cancer therapy. Thus, this work provides a new way toward designing stimulus-responsive functionalized NCOFs and promotes their potential application as an on-demand drug delivery system in the field of cancer treatment.
PubMed: 38952941
DOI: 10.1039/d4ra01955e -
Physical Chemistry Chemical Physics :... Jul 2024The hallmark of amyloidosis, such as Alzheimer's disease and Parkinson's disease, is the deposition of amyloid fibrils in various internal organs. The onset of the...
The hallmark of amyloidosis, such as Alzheimer's disease and Parkinson's disease, is the deposition of amyloid fibrils in various internal organs. The onset of the disease is related to the strength of cytotoxicity caused by toxic amyloid species. Furthermore, amyloid fibrils show polymorphism, where some types of fibrils are cytotoxic while others are not. It is thus essential to understand the molecular mechanism of cytotoxicity, part of which is caused by the interaction between amyloid polymorphic fibrils and cell membranes. Here, using amyloid polymorphs of hen egg white lysozyme, which is associated with hereditary systemic amyloidosis, showing different levels of cytotoxicity and liposomes of DMPC and DMPG, changes in the secondary structure of the polymorphs and the structural state of phospholipid membranes caused by the interaction were investigated using vacuum-ultraviolet circular dichroism (VUVCD) and Laurdan fluorescence measurements, respectively. Analysis has shown that the more cytotoxic polymorph increases the antiparallel β-sheet content and causes more disorder in the membrane structure while the other less cytotoxic polymorph shows the opposite structural changes and causes less structural disorder in the membrane. These results suggest a close correlation between the structural properties of amyloid fibrils and the degree of structural disorder of phospholipid membranes, both of which are involved in the fundamental process leading to amyloid cytotoxicity.
PubMed: 38952218
DOI: 10.1039/d4cp00965g -
The New Phytologist Jul 2024Plant homeodomain leucine zipper IV (HD-Zip IV) transcription factors (TFs) contain an evolutionarily conserved steroidogenic acute regulatory protein (StAR)-related...
Plant homeodomain leucine zipper IV (HD-Zip IV) transcription factors (TFs) contain an evolutionarily conserved steroidogenic acute regulatory protein (StAR)-related lipid transfer (START) domain. While the START domain is required for TF activity, its presumed role as a lipid sensor is not clear. Here we used tandem affinity purification from Arabidopsis cell cultures to demonstrate that PROTODERMAL FACTOR2 (PDF2), a representative member that controls epidermal differentiation, recruits lysophosphatidylcholines (LysoPCs) in a START-dependent manner. Microscale thermophoresis assays confirmed that a missense mutation in a predicted ligand contact site reduces lysophospholipid binding. We additionally found that PDF2 acts as a transcriptional regulator of phospholipid- and phosphate (Pi) starvation-related genes and binds to a palindromic octamer with consensus to a Pi response element. Phospholipid homeostasis and elongation growth were altered in pdf2 mutants according to Pi availability. Cycloheximide chase experiments revealed a role for START in maintaining protein levels, and Pi starvation resulted in enhanced protein destabilization, suggesting a mechanism by which lipid binding controls TF activity. We propose that the START domain serves as a molecular sensor for membrane phospholipid status in the epidermis. Our data provide insights toward understanding how the lipid metabolome integrates Pi availability with gene expression.
PubMed: 38952028
DOI: 10.1111/nph.19917 -
Lipids in Health and Disease Jun 2024Glycerophospholipids (GPLs) are essential for cell membrane structure and function. Sphingomyelin and its metabolites regulate cell growth, apoptosis, and stress...
BACKGROUND
Glycerophospholipids (GPLs) are essential for cell membrane structure and function. Sphingomyelin and its metabolites regulate cell growth, apoptosis, and stress responses. This study aimed to investigate lipid metabolism in patients experiencing sudden sensorineural hearing loss across all frequencies (AF-SSNHL).
METHODS
The study included 60 patients diagnosed with unilateral AF-SSNHL, among whom 30 patients had a level of hearing improvement ≥ 15 dB after 6 months of follow-up. A propensity score-matched (2:1) control group was used. Liquid chromatography‒mass spectrometry based untargeted lipidomics analysis combined with multivariate statistics was performed to investigate the lipids change. The "lipidome" R package and weighted gene co-expression network analysis (WGCNA) were utilised to assess the lipids' structural features and the association between lipids and hearing.
RESULTS
Lipidomics successfully differentiated the AF-SSNHL group from the control group, identifying 17 risk factors, mainly including phosphatidylcholine (PC), phosphatidylethanolamine (PE), and related metabolites. The ratios of lysophosphatidylcholine/PC, lysophosphatidylethanolamine/PE, and lysodimethylphosphatidylethanolamine/PE were upregulated, while some glycerophospholipid (GPL)-plasmalogens were downregulated in the AF-SSNHL group, indicating abnormal metabolism of GPLs. Trihexosylceramide (d34:1), PE (18:1e_22:5), and sphingomyelin (d40:3) were significantly different between responders and nonresponders, and positively correlated with hearing improvement. Additionally, the results of the WGCNA also suggested that partial GPL-plasmalogens were positively associated with hearing improvement.
CONCLUSION
AF-SSNHL patients exhibited abnormally high blood lipids and pronounced GPLs metabolic abnormalities. Sphingolipids and GPL-plasmalogens had an association with the level of hearing improvement. By understanding the lipid changes, clinicians may be able to predict the prognosis of hearing recovery and personalize treatment approaches.
Topics: Humans; Female; Male; Middle Aged; Biomarkers; Hearing Loss, Sensorineural; Lipid Metabolism; Lipidomics; Adult; Hearing Loss, Sudden; Glycerophospholipids; Aged; Phosphatidylethanolamines; Phosphatidylcholines; Lysophosphatidylcholines; Sphingomyelins; Lysophospholipids
PubMed: 38951804
DOI: 10.1186/s12944-024-02189-8 -
Hypertension Research : Official... Jul 2024Pregnancy-induced hypertension (PIH), a prominent determinant of maternal mortality and morbidity worldwide, is hindered by the absence of efficacious biomarkers for...
Pregnancy-induced hypertension (PIH), a prominent determinant of maternal mortality and morbidity worldwide, is hindered by the absence of efficacious biomarkers for early diagnosis, contributing to suboptimal outcomes. Here, we explored potential causal relationships between blood metabolites and the risk of PIH using Mendelian randomization (MR). We employed a two-sample univariable MR approach to empirically estimate the causal relationships between 249 circulating metabolites and PIH. Inverse variance weighted, MR-egger, weight median, simple mode, and weighted mode methods were used for causal estimates. The exposure-to-outcome directionality was confirmed with the MR Steiger test. The Bayesian model averaging MR (MR-BMA) method was applied to detect the predominant causal metabolic traits with alignment for pleiotropy effects. In the primary analysis, analyzing 249 metabolites, we identified 25 causally linked to PIH, including 11 lipid-related traits and 6 associated with fatty acid (un)saturation. Importantly, MR-BMA analyses corroborated the total concentration of branched-chain amino acids(total-BCAA) to be the highest rank causal metabolite, followed by leucine (Leu), phospholipids to total lipids ratio in medium LDL (M-LDL-PL-pct), and Val (all P < 0.05). The directionality of causality predicted by univariable MR and MR-BMA for these metabolites remained consistent. This study highlights the causal connection between metabolites and PIH risk. It highlighted BCAAs as the strongest causal candidates warranting further investigation. Since PIH typically occurs in the second and third trimesters, extending these findings could inform earlier strategies to reduce its risk. Directed acyclic graph of the MR framework investigating the causal relationship between metabolites and PIH. MR: Mendelian randomization; GIVs: genetic instrument variables; SNPs: single-nucleotide polymorphism; IVW: inverse variance weighted; WM: weighted median; PIH: pregnancy-induced hypertension; SM: significant metabolite; MR-BMA: Bayesian model averaging MR.
PubMed: 38951678
DOI: 10.1038/s41440-024-01787-4