Lipid Transport Function Research Articles

Adipocytes Size of the Epicardial Adipose Tissue in Patients With Coronary Artery Disease and Coronary Atherosclerosis: Relationship With Parameters of Blood Lipid Transport Function, Carbohydrate Metabolism and Inflammatory Markers

Aim. To assess the potential relationship between morphometric characteristics of adipocytes in epicardial and subcutaneous adipose tissue (EAT, SAT) and the lipid transport function of the blood, glucose e metabolism, and inflammatory biomarkers in patients with ischemic heart disease (IHD) after coronary artery bypass grafting.Material and methods. The study included 47 patients (33 men and 14 women) aged 53-72 years with chronic IHD. The study material was EAT and SAT adipocytes obtained from intraoperative explants. The size of EAT and SAT adipocytes and the proportion of EAT and SAT adipocytes with ≥100 μm and ≤50 μm sizes were determined. Carbohydrate metabolism parameters, blood lipid transport function, and inflammatory biomarkers were assessed. Surrogate indices of insulin resistance (IR) were calculated.Results. The mean size of EAT adipocytes, in contrast to SAT adipocytes, correlated (p<0.05) with serum concentrations of tumor necrosis factor alpha (TNF-α) (rs=0.43), triglycerides (TG) (rs=0.36), interleukin (IL)-1β (rs=0.29), basal C-peptide (rs=0.40) and TyG index (rs=0.32). Male gender and blood concentrations of basal C-peptide and TG in combination were identified as statistically significant determinants of an increase in the mean size of EAT adipocytes. The threshold values of TG and non-high-density lipoprotein cholesterol (nHDL-C) associated with an increase in the mean size of EAT adipocytes ≥87.61 μm were 1.4 and 2.63 mM, respectively. Patients with TG concentrations ≥1.4 mM had a greater size and proportion of hypertrophied EAT adipocytes, IR indices, and higher blood concentrations of basal glucose, high-sensitivity C-reactive protein, TNF-α, and IL-1β. TG concentrations of 1.2-1.4 mM, compared with concentrations <1.2 mM, were associated with a greater mean size of EAT adipocytes and higher serum IL-10 concentrations. Patients with non-HDL-C ≥2.63 mM, compared with its lower concentrations, had more pronounced hypertrophy of EAT adipocytes.Conclusion. Disorders in the morphometric characteristics of EAT adipocytes, in contrast to SAT adipocytes, are associated with increased blood concentrations of TG, non-HDL-C, inflammatory markers, and increased IR indices. It was shown for the first time that a combination of three factors, male gender, blood concentrations of basal C-peptide, and TG, independently of other indicators describe the variability of the mean size of EAT adipocytes. Increases in TG from 1.2 to 1.4 mM are associated with a larger size of EAT adipocytes and cytokine imbalance. Our data confirm the validity of identifying optimal blood concentrations of TG and non-HDL-C in patients with IHD and coronary atherosclerosis.

Pangenome evaluation of gene essentiality in Streptococcus pyogenes.

Bacterial species often consist of strains with variable gene content, collectively referred to as the pangenome. Variations in the genetic makeup of strains can alter bacterial physiology and fitness. To define biologically relevant genes of a genome, genome-wide transposon mutant libraries have been used to identify genes essential for survival or virulence in a given strain. Such phenotypic studies have been conducted in four different genotypes of the human pathogen Streptococcus pyogenes, yet challenges exist in comparing results across studies conducted in different genetic backgrounds and conditions. To advance genotype to phenotype inferences across different S. pyogenes strains, we built a pangenome database of 249 S. pyogenes reference genomes. We systematically re-analyzed publicly available transposon sequencing datasets from S. pyogenes using a transposon sequencing-specific analysis pipeline, Transit. Across four genetic backgrounds and nine phenotypic conditions, 355 genes were essential for survival, corresponding to ~24% of the core genome. Clusters of Orthologous Genes (COG) categories related to coenzyme and lipid transport and growth functions were overrepresented as essential. Finally, essential operons across S. pyogenes genotypes were defined, with an increased number of essential operons detected under in vivo conditions. This study provides an extendible database to which new studies can be added, and a searchable html-based resource to direct future investigations into S. pyogenes biology.IMPORTANCEStreptococcus pyogenes is a human-adapted pathogen occupying restricted ecological niches. Understanding the essentiality of genes across different strains and experimental conditions is important to direct research questions and efforts to prevent the large burden of disease caused by S. pyogenes. To this end we systematically reanalyzed transposon sequencing studies in S. pyogenes using transposon sequencing-specific methods, integrating them into an extendible meta-analysis framework. This provides a repository of gene essentiality in S. pyogenes which was used to highlight specific genes of interest and for the community to guide future phenotypic studies.

Uncovering mechanisms of interorganelle lipid transport by enzymatic mass tagging.

Lipid trafficking is critical for the biogenesis and expansion of organelle membranes. Lipid transport proteins (LTPs) have been proposed to facilitate lipid transport at contact sites between organelles. Despite the fundamental importance of LTPs in cell physiology, our knowledge on the mechanisms of interorganelle lipid distribution remains poor due to the scarcity of assays to monitor lipid flux in vivo. In this review, we highlight the recent development of a versatile method named METALIC (Mass tagging-Enabled Tracking of Lipids in Cells), which uses a combination of enzymatic mass tagging and mass spectrometry to track lipid flux between organelles inside living cells. We discuss the methodology, its distinct advantages, limitations as well as its potential to unearth the pipelines of lipid transport and LTP function in vivo.

A Loss of Function in LprG-Rv1410c Homologues Attenuates Growth during Biofilm Formation in Mycobacterium smegmatis.

MmpL (mycobacterial membrane protein large) proteins are integral membrane proteins that have been implicated in the biosynthesis and/or transport of mycobacterial cell wall lipids. Given the cellular location of these proteins, however, it is unclear how cell wall lipids are transported beyond the inner membrane. Moreover, given that mycobacteria grow at the poles, we also do not understand how new cell wall is added in a highly localized and presumably coordinated manner. Here, we examine the relationship between two lipid transport pathways associated with the proteins MmpL11 and LprG-Rv1410c. The lipoprotein LprG has been shown to interact with proteins involved in cell wall processes including MmpL11, which is required in biofilms for the surface localization of certain lipids. Here we report that deletion of mmpL11 (MSMEG_0241) or the lprG-rv1410c operon homologues MSMEG_3070-3069 in Mycobacterium smegmatis produced similar biofilm defects that were distinct from that of the previously reported mmpL11 transposon insertion mutant. Analysis of pellicle biofilms, bacterial growth, lipid profiles, and gene expression revealed that the biofilm phenotypes could not be directly explained by changes in the synthesis or localization of biofilm-related lipids or the expression of biofilm-related genes. Instead, the shared biofilm phenotype between ΔMSMEG_3070-3069 and ΔmmpL11 may be related to their modest growth defect, while the origins of the distinct mmpL11::Tn biofilm defect remain unclear. Our findings suggest that the mechanisms that drive pellicle biofilm formation in M. smegmatis are not connected to crosstalk between the LprG-Rv1410c and MmpL11 pathways and that any functional interaction between these proteins does not relate directly to their lipid transport function.

Radix Saposhnikoviae enhancing Huangqi Chifeng Decoction improves lipid metabolism in AS mice

Ethnopharmacological relevanceHuangqi Chifeng decoction (HQCF) combined with parsnips is a classic Chinese traditional medicine formula that has certain advantages in the clinical treatment of cardiovascular and cerebrovascular diseases. At present, there is an absence of research on the regulatory effect and mechanism of this formula on atherosclerosis (AS). The synergistic effect of Radix Saposhnikoviae (RS) in HQCF is also unclear. Aim of the studyThis study was designed to investigate the role of RS, which is designed as a guide drug for HQCF, in improving the lipid metabolism of AS. Materials and methodsIn this study, we studied the effect of HQCF on ApoE−/− mice before and after RS compatibility. Hematoxylin and eosin (HE) staining and oil red staining were used to evaluate atherosclerotic lesions and lipid accumulation in the aorta and liver, respectively. The expression of adenosine monophosphate-activated protein kinase (AMPK) and pAMPK in the aorta was measured by immunofluorescence, and AMPK and sterol regulatory element binding protein-1 (SREBP-1),fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC) in liver tissue were measured by Western blot analysis. Metabolomics was used to compare the changes in serum and liver metabolites of ApoE−/− mice before and after RS combination. ResultsCompared with the control group, the serum lipid levels of ApoE−/− mice increased, the aortic intima thickened with plaque formation, and liver tissue pathological changes and lipid deposition occurred. Both (HQCFT without RS)HQCS and HQCF can improve the pathological condition of tissue and regulate the blood lipid level. It was noted that HQCF could promote the phosphorylation of AMPK to activate it, inhibit the expression of SREBP-1c and FAS, reduce lipid synthesis, and inhibit ACC to promote the oxidative decomposition of fatty acids. Serum and liver metabolome results showed that HQCS and HQCF treated AS mainly by regulating glycerophospholipid metabolism, sphingolipid metabolism and the arachidonic acid metabolism pathway. Importantly, HQCF showed better efficacy in regulating lipid metabolism than the HQCS group. ConclusionHQCF decoction reduces atherosclerotic lesions in the aorta and lipid accumulation in the liver, which may regulate lipid transport and metabolic function by activating the AMPK pathway. These effects can be attributed to the guidance and synergism of RS.

Biological roles of plant synaptotagmins

Plant synaptotagmins (SYTs) are resident proteins of the endoplasmic reticulum (ER). They are characterized by an N-terminal transmembrane region and C2 domains at the C-terminus, which tether the ER to the plasma membrane (PM). In addition to their tethering role, SYTs contain a lipid-harboring SMP domain, essential for shuttling lipids between the ER and the PM. There is now abundant literature on Arabidopsis SYT1, the best-characterized family member, which link it to biotic and abiotic responses as well as to ER morphology. Here, we review the current knowledge of SYT members, focusing on their role in stress, and discuss how these roles can be related to their tethering and lipid transport functions. Finally, we contextualize this information about SYTs with their homologs, the yeast tricalbins and the mammalian extended synaptotagmins.

Quantifying Functional Impairment of ABCA3 Variants Associated with Interstitial Lung Disease.

ATP-binding cassette subfamily A member 3 (ABCA3) is a lipid transporter within alveolar type II cells. Patients with bi-allelic variants in ABCA3 may suffer from a variable severity of interstitial lung disease. We characterized and quantified ABCA3 variants' overall lipid transport function by assessing the in vitro impairment of its intracellular trafficking and pumping activity. We expressed the results relative to the wild type, integrated the quantitative readouts from eight different assays and used newly generated data combined with previous results to correlate the variants' function and clinical phenotype. We differentiated normal (within 1 normalized standard deviation (nSD) of the wild-type mean), impaired (within 1 to 3 nSD) and defective (beyond 3 nSD) variants. The transport of phosphatidylcholine from the recycling pathway into ABCA3+ vesicles proved sensitive to the variants' dysfunction. The sum of the quantitated trafficking and pumping predicted a clinical outcome. More than an approximately 50% loss of function was associated with considerable morbidity and mortality. The in vitro quantification of ABCA3 function enables detailed variant characterization, substantially improves the phenotype prediction of genetic variants and possibly supports future treatment decisions.

Correlation of epicardial adipocytes hypertrophy with adipokines, inflammation and glucose and lipid metabolism

The changes of epicardial adipose tissue’s (EAT) morphofunctional characteristics represent an important factor of cardiometabolic impairments development. However, factor data determining the severity of EAT adipocytes’ hypertrophy in patients with coronary atherosclerosis are absent in literature.Aim: To compare the size of the EAT adipocyte and the percentage of hypertrophied adipocytes with the parameters of glucose/insulin metabolism, blood lipid transport function, adipokines’ profile and serum levels of high sensitive C-reactive protein (hsCRP) in patients with chronic coronary artery disease (CAD) undergoing coronary artery bypass grafting (CABG); to establish statistically significant determinants of a pronou ced degree of EAT adipocytes’ hypertrophy.Material and Methods. The study included 42 patients (m/f 28/14) aged 53–72 y.o. with CAD, who underwent CABG. The material for the study was EAT adipocytes obtained by the enzymatic method from intraoperative explants. The basal blood levels of glycemia, insulinemia, C-peptide, blood lipid transport function, adipokines and hsCRP were determined. The median indicators of the size of EAT adipocytes and the proportion of EAT adipocytes over 100 μm were 87.32 μm and 14.64%, respectively. The total sample of patients was divided into two groups: gr. 1 with an average size of EAT adipocytes less than or equal to 87.32 μm and gr. 2 with an average size of EAT adipocytes more than 87.32 μm. Gr. 2 had higher body mass index, waist and hip circumferences, triglycerides, hsCRP, and lower adiponectin levels, while the median proportion of hypertrophied adipocytes was three times higher than in group 1. A model of multiple logistic regression was constructed, according to which statistically significant determinants of the pronounced EAT adipocytes’ hypertrophy are represented by the decreased level of adiponectin, and increased concentrations of hsCRP and C-peptide, which reflects the biosynthesis and secretion of insulin. The predictive accuracy of the model was 82%, sensitivity 85%, specificity 79%, AUC = 0.89.Conclusion. Our results indicate a close correlation between the development of EAT adipocytes hypertrophy, impaired production of adiponectin, insulin, and inflammation processes. Concentrations of adiponectin, hsCRP, and basal C-peptide in the blood are biomarkers that accurately determine the presence of EAT adipocyte hypertrophy.

Proteomics of high-density lipoprotein subfractions and subclinical atherosclerosis in type 1 diabetes mellitus: a case–control study

BackgroundSubclinical atherosclerosis is frequently observed in type 1 diabetes (T1D) although the mechanisms and markers involved in the evolution to established cardiovascular disease are not well known. High-density lipoprotein cholesterol in T1D is normal or even high, and changes in its functionality and proteomics are considered. Our aim was to evaluate the proteomics of HDL subfractions in T1D and control subjects and its association with clinical variables, subclinical atherosclerosis markers and HDL functionality.MethodsA total of 50 individuals with T1D and 30 matched controls were included. Carotid-femoral pulse wave velocity (PWV), flow-mediated vasodilation (FMD), cardiovascular autonomic neuropathy (CAN), and ten-year cardiovascular risk (ASCVDR) were determined. Proteomics (parallel reaction monitoring) was determined in isolated HDL2 and HDL3 that were also utilized to measure cholesterol efflux from macrophages.ResultsAmong 45 quantified proteins, 13 in HDL2 and 33 in HDL3 were differentially expressed in T1D and control subjects. Six proteins related to lipid metabolism, one to inflammatory acute phase, one to complement system and one to antioxidant response were more abundant in HDL2, while 14 lipid metabolism, three acute-phase, three antioxidants and one transport in HDL3 of T1D subjects. Three proteins (lipid metabolism, transport, and unknown function) were more abundant in HDL2; and ten (lipid metabolism, transport, protease inhibition), more abundant in HDL3 of controls. Individuals with T1D had higher PWV and ten-year ASCVDR, and lower FMD, Cholesterol efflux from macrophages was similar between T1D and controls. Proteins in HDL2 and HDL3, especially related to lipid metabolism, correlated with PWV, CAN, cholesterol efflux, HDLc, hypertension, glycemic control, ten-year ASCVDR, and statins use.ConclusionHDL proteomics can be predictive of subclinical atherosclerosis in type 1 diabetes. Proteins that are not involved in reverse cholesterol transport may be associated with the protective role of HDL.

Human ApoE2 Endows Stronger Contractility in Rat Cardiomyocytes Enhancing Heart Function

(1) Background: Apolipoprotein E (ApoE) is a critical plasma apolipoprotein for lipid transport and nonlipid-related functions. Humans possess three isoforms of ApoE (2, 3, and 4). ApoE2, which exhibits beneficial effects on cardiac health, has not been adequately studied. (2) Methods: We investigated the cardiac phenotypes of the humanized ApoE knock-in (hApoE KI) rats and compared to wild-type (WT) and ApoE knock-out (ApoE KO) rats using echocardiography, ultrasound, blood pressure measurements, histology strategies, cell culture, Seahorse XF, cardiomyocyte contractility and intracellular Ca2+ tests, and Western blotting; (3) Results: hApoE2 rats exhibited enhanced heart contractile function without signs of detrimental remodeling. Isolated adult hApoE2 cardiomyocytes had faster and stronger sarcomere contractility because of more mitochondrial energy generation and stimulation-induced fast and elevated intracellular Ca2+ transient. The abundant energy is a result of elevated mitochondrial function via fatty acid β-oxidation. The fast and elevated Ca2+ transient is associated with decreased sarcoplasmic reticulum (SR) Ca2+ ATPase (SERCA2) and increased expression of cardiac ryanodine receptor 2 (RyR2) conducting a potent Ca2+ release from SR.; (4) Conclusions: Our studies validated the association of polymorphic ApoEs with cardiac health in the rat model, and revealed the possible mechanisms of the protective effect of ApoE2 against heart diseases.

Clinical Significance of Lipid Transport Function of ABC Transporters in the Innate Immune System.

ABC transporters are a large family of proteins that transport a variety of substrates across cell plasma membranes. Because of this, they are involved in many physiological processes. It is of interest to note that many ABC transporters are involved in the transport of various lipids. In addition, this function may be related to the innate immune system. The evidence that ABC transporters are involved in the regulation of the innate immune system through the transport of various substances greatly enhances the understanding of their clinical significance. ABC transporters are involved in the cellular homeostasis of cholesterol as well as in the regulation of its content in lipid rafts. Through these mechanisms, they can regulate the function of membrane proteins, including receptors of the innate immune system. By regulating lipid transport, some members of ABC transporters are involved in phagocytosis. In addition, ABC transporters are involved in the transport of lipopolysaccharide, lipid mediators of inflammation, and perform other functions in the innate immune system.

Potential Tear Biomarkers for the Diagnosis of Parkinson's Disease-A Pilot Study.

Parkinson’s disease (PD) is the second most common neurodegenerative disease after Alzheimer’s disease. In this study, the tear proteome profile of patients with idiopathic PD (iPD, n = 24), carriers of the E46K-SNCA mutation (n = 3) and healthy control (CT, n = 27) subjects was analyzed to identify candidate biomarkers for the diagnosis of PD. An observational, prospective and case-control pilot study was carried out, analyzing the participants tear samples by nano-liquid chromatography–mass spectrometry (nLC–MS/MS) and assessing their neurological impairment. The proteomic data obtained are available at ProteomeXchange with identifier 10.6019/PXD028811. These analyses led to the identification of 560 tear proteins, some of which were deregulated in PD patients and that have been implicated in immune responses, inflammation, apoptosis, collagen degradation, protein synthesis, defense, lipid transport and altered lysosomal function. Of these proteins, six were related to neurodegenerative processes and showed a good capacity to classify patients and controls. These findings revealed that certain proteins were upregulated in the tears of PD patients, mainly proteins involved in lysosomal function. Thus, in this study, tear proteins were identified that are implicated in neurodegeneration and that may be related to an aggressive disease phenotype in PD patients.

A New lncRNA, lnc-LLMA, Regulates Lipid Metabolism in Pig Hepatocytes.

A large variety of long noncoding RNAs (lncRNAs) have been discovered through high-throughput sequencing technology and some have been demonstrated to play important roles in lipid metabolism regulation. In our study, we found a highly expressed lncRNA (lnc-LLMA, liver lipid metabolism-associated lncRNA) in the liver of Duroc pigs, which was enriched in the nucleus. It displays potent tissue specificity among different pig breeds. Overexpression of lnc-LLMA can cause a decline in intracellular triglyceride (TG) levels and increases in ATP and mitochondrial DNA levels in pig primary hepatocytes and HepG2 cells. In addition, the expression levels of MTTP, APOB, CPT1α, and other genes were increased by overexpression of lnc-LLMA. It downregulated expression of G6Pase and SREBP1 genes. Chromatin isolation by RNA purification (ChRIP) experiments demonstrated that microsomal triglyceride transfer protein (MTTP) and glycogen synthase 2 (GYS2) were the potential interacting proteins of lnc-LLMA. The overexpression of the GYS2 gene rescued the decreasing intracellular TG levels caused by the increase of lnc-LLMA. Similarly, overexpression of MTTP was also able to save the lnc-LLMA-induced decrease in intracellular TG. Our study demonstrated that this novel lncRNA was closely related to lipid metabolism and affected lipid transport and mitochondrial function through MTTP and GYS2. Our results provided a new direction for further studying the effect of lncRNA on lipid metabolism regulation.

The PH-like Domain of VPS13 Proteins - a Determinant of Localization to the Golgi Apparatus or to the Plasma Membrane.

Mutations in the four human genes VPS13A-D, encoding vacuolar protein sorting 13 (VPS13A-D) proteins, result in developmental or neurodegenerative diseases. Understanding the functioning of VPS13 proteins in physiology and pathology is a hot topic of research. Especially interesting is how VPS13 proteins are localized to specific membrane contact sites and function in lipid transport. Recently, the C-terminal Pleckstrin Homology (PH)-like domains of yeast Vps13 and human VPS13A were found to bind Arf1 GTPase and to phosphoinositol 4,5-bisphosphate. Here, hypotheses on the importance of the dual binding ability of the PH-like domain of VPS13A protein for cell physiology are presented. While yeast Vps13, together with Arf1 GTPase, is important for protein sorting in the Trans Golgi Network (TGN), the localization of VPS13A in TGN is speculated to restrict the binding of VPS13A to the plasma membrane.

Resolvin E1-ChemR23 Axis Regulates the Hepatic Metabolic and Inflammatory Transcriptional Landscape in Obesity at the Whole Genome and Exon Level.

Resolvin E1 (RvE1) is an immunoresolvent that is synthesized from eicosapentaenoic acid and can bind the receptor ERV1/ChemR23. We previously showed activation of the RvE1-ChemR23 axis improves hyperglycemia and hyperinsulinemia of obese mice; however, it remains unclear how RvE1 controls glucose homeostasis. Here we investigated hepatic metabolic and inflammatory transcriptional targets of the RvE1-ChemR23 axis using lean and obese wild type (WT) and ChemR23 knockout (KO) mice. We conducted an in-depth transcriptional study by preforming whole gene-level and exon-level analyses, which provide insight into alternative splicing variants and miRNA regulation. Compared to controls, WT and KO obese mice in the absence of RvE1 displayed similar gene-level profiles, which entailed dysregulated pathways related to glucose homeostasis. Notably, obese WT mice relative to lean controls showed a robust decrease in pathways related to the biosynthesis of unsaturated fatty acids. At the exon-level, obese ChemR23 KOs compared to obese WT mice displayed changes in pathways related to hepatic lipid transport, cholesterol metabolism, and immunological functions such as complement cascades and platelet activation. Importantly, upon RvE1 administration to WT obese mice, we discovered upregulated genes in pathways relating to insulin sensitivity and downregulated genes related to regulators of TGF-β signaling. This transcriptional profile was generally not recapitulated with obese ChemR23 KO mice administered RvE1. Collectively, gene and exon-level analyses suggest RvE1 controls the hepatic transcriptional profile related to glucose homeostasis, insulin sensitivity, and inflammation in a manner that is largely dependent on ChemR23. These studies will drive future mechanistic experiments on the RvE1-ChemR23 axis.

ABCA7 gene as a potential therapeutic target in the management of Alzheimer's disease

ABCA7 is a gene that belong to the family of ATP-binding cassette (ABC) transporter gene superfamily. Based on their structure and sequence homology, ABC transporters are divided into seven sub families. Asides from its function in lipid transport, high levels of ABCA7 is expressed in the hippocampus and has been identified with Alzheimer's disease (AD) risk. Over time, research has been done to identify therapeutic targets in the management of Alzheimer's disease.A literature search on ABCA7 and therapeutic targets was carried out through the PubMed database. The exclusion and inclusion criteria were used to achieve reliable and accurate results.Using the string "ABCA7 AND Alzheimer's", 197 results were obtained from the search as at January 24th , 2021. The search was narrowed down by using the string "ABCA7 AND Therapeutic targets". The 2nd search yielded 17 results after which some papers were excluded. Findings revealed that 10 (59%) out of 17 papers obtained from the search associated ABCA7 with late-onset AD risk. This indicate the relevance of ABCA7 in the pathogenesis of Alzheimer's disease. Out of the 10 papers studied, 5 (50%) included ABCA7 gene in studies pertaining to therapeutic targets in Alzheimer's disease. This shows that ABCA7 is considered a therapeutic target for Alzheimer's disease.Despite the progress made so far, more work still needs to be done to validate ABCA7 gene as a therapeutic tool in AD management. It is hoped that this review will encourage more research in this aspect of Alzheimer's disease management.

Association of decreased glomerular filtration rate with renal hemodynamic disorders and inflammatory biomarkers in patients with medically-controlled hypertension of high cardiovascular risk

Aim. To assess markers of chronic kidney disease (CKD) in patients with medically-controlled hypertension (HTN) (<140/90 mm Hg), as well as to analyze potential association of decreased glomerular filtration rate (GFR) <60 ml/min/1,73 m2 with clinical data and therapy; to establish significant determinants of GFR decrease in this category of patients.Material and methods. The study included 70 patients with HTN and office blood pressure (BP) <140/90 mm Hg aged 64 (57; 68) years (men, 48,6%), of whom 40 patients were examined within the Russian multicenter CHRONOGRAPH program. Office BP was 130 (120; 140)/80 (72; 82) mm Hg. GFR and albuminuria were assessed. Twenty-four-hour BP monitoring and Doppler ultrasound of renal blood flow with estimation of resistance indices (RI) were performed. The content of highsensitivity C-reactive protein (hsCRP), interleukins (IL) 1β, 6, 10 and lipid transport function parameters was determined.Results. CKD markers were detected in 31,4% of patients (in 27,1% — a decrease in GFR <60 ml/min/1,73 m2; in 12,9% — pathological albuminuria). Patients with CKD markers were older, had higher office systolic BP and nocturnal pulse pressure, higher blood hsCRP and RI levels throughout the renal flow, and lower high-density lipoprotein cholesterol levels. In the presence of CKD markers, calcium channel blockers, aldosterone receptor antagonists and statins were used more often. The results of correlation analysis were used to determine the determinants of GFR decline. In the general group, GFR values had inverse correlations with age (Rs=-0,58, p<0,0001), segmental intrarenal artery RI (Rs= -0,4232, p=0,0005), blood hsCRP (Rs=-0,3998, p=0,0007), IL-1β (Rs=-0,3139, p=0,0086), office BP and some 24-hour BP parameters. In the presence of CKD markers, a direct association of GFR and IL-10 was determined (Rs=0,4293, p=0,046). In the absence of such markers, GFR had an inverse correlation with IL-1β content (Rs=-0,3110, p=0,0333). A multiple linear regression model included following independent determinants of GFR: age, blood hsCRP and RI in the segmental intrarenal arteries.Conclusion. Among patients with medically-controlled HTN of high cardiovascular risk, a high prevalence of CKD markers was revealed (31,4%). Compared with patients with preserved renal function, in the presence of CKD markers, there were higher levels of office systolic BP, nocturnal pulse pressure, blood hsCRP, and intrarenal artery RI. Associations were established between GFR and the levels of hsCRP, IL-1β and IL-10, which confirms the pathological role of inflammatory biomarkers in developing renal dysfunction in high-risk HTN. Age, elevated blood hsCRP levels, and intrarenal artery RI are independent determinants of decreased GFR in patients with medically-controlled HTN of high and very high cardiovascular risk. The data obtained shows the need for early prescription of combination antihypertensive therapy with nephro- and vasoprotective effects in this category of patients, as well as with an ability to depress the chronic subclinical inflammation.

The level of reactive oxygen species production by adipocytes of epicardial adipose tissue is associated with an increase in postprandial glycemia in patients with severe coronary atherosclerosis

The mechanisms of oxidative stress in adipocytes of local fat depots in patients with cardiometabolic diseases have been studied insufficiently.Purpose. To study the levels of reactive oxygen species (ROS) production in adipocytes of epicardial (EAT) and subcutaneous adipose tissue (SAT) in patients with stable coronary artery disease (CAD) and severe coronary atherosclerosis who underwent coronary artery bypass grafting; to investigate the potential relationships between the levels of ROS production by EAT and SAT adipocytes and obesity parameters, EAT accumulation, basal and postprandial glycemia, and blood lipid transport function.Material and Methods. The study included 19 patients (12 men and 7 women including 6 patients (31.5%) with type 2 diabetes mellitus) aged 53–72 years with stable CAD and severe coronary atherosclerosis. The material for the study was EAT and SAT adipocytes obtained by the enzymatic method from intraoperative explants. The ROS level in adipocytes was determined using the fluorimetry with 2,3-dihydrodichlorofluorescein diacetate. Anthropometric parameters of obesity and EAT thickness were studied using echocardiography. The blood lipid transport function and the levels of basal and postprandial glucose were assessed.Results. The levels of ROS production by EAT and SAT adipocytes in the overall group of patients did not differ significantly and amounted to 1710 (1608; 2079) and 1876 (1374; 2215) arbitrary units, respectively. The level of ROS production by SAT adipocytes did not correlate with the parameters of obesity, EAT thickness, or biomarker levels. The level of ROS production by EAT adipocytes directly correlated with the level of postprandial glycemia (rs = 0.62, p < 0.05), but did not correlate with measures of general and abdominal obesity, EAT thickness, and dyslipidemia. The level of ROS production by EAT adipocytes in patients with postprandial glycemia ≥ 7.7 mmol/L (n = 9) exceeded the corresponding value in patients with lower level of postprandial glycemia (n = 10): 2079 (1710; 2458) against 1625.5 (1332; 1699) arbitrary units (p = 0.015), respectively.Conclusion. We showed for the first time that the level of ROS production by EAT adipocytes in CAD patients with severe coronary atherosclerosis was directly associated with the level of postprandial glycemia. The highest level of ROS production in EAT adipocytes occurred in these patients when the level of postprandial glycemia exceeds 7.7 mmol/L.

Structure and mechanism of blood-brain-barrier lipid transporter MFSD2A.

MFSD2A is a sodium-dependent lysophosphatidylcholine symporter that is responsible for the uptake of docosahexaenoic acid into the brain1,2, which is crucial for the development and performance of the brain3. Mutations that affect MFSD2A cause microcephaly syndromes4,5. The ability of MFSD2A to transport lipid is also a key mechanism that underlies its function as an inhibitor of transcytosis to regulate the blood-brain barrier6,7. Thus, MFSD2A represents an attractive target for modulating the permeability of the blood-brain barrier for drug delivery. Here we report the cryo-electron microscopy structure of mouse MFSD2A. Our structure defines the architecture of this important transporter, reveals its unique extracellular domain and uncovers its substrate-binding cavity. The structure-together with our functional studies and molecular dynamics simulations-identifies a conserved sodium-binding site, reveals a potential lipid entry pathway and helps to rationalize MFSD2A mutations that underlie microcephaly syndromes. These results shed light on the critical lipid transport function of MFSD2A and provide a framework to aid in the design of specific modulators for therapeutic purposes.

Identification and functional analysis of the MdLTPG gene family in apple

Cuticular wax is synthesized from intracellular lipids that are exported by epidermal cells, and plant lipid transfer proteins (LTPs) play an important role in this process. The glycosylphosphatidylinositol (GPI)-anchored LTPs (LTPGs) are a large subgroup within the LTP family and function in lipid transport and wax formation. Although LTPG family members have been identified in several plant species, the LTPG gene family of apple (Malus domestica) remains uncharacterized. In this paper, we identified 26 potential LTPG genes by searching apple whole-genome annotation files using “GPI-anchored” and “lipid transferase” as keywords. Twenty of the 26 putative LTPG genes were confirmed as MdLTPG family members based on their subcellular localization predictions. The MdLTPGs were divided into four classes based on phylogenetic analysis and functional domain prediction. One member of each class was analyzed for subcellular localization, and all identified members were located on the plasma membrane. Most MdLTPG genes were induced by abiotic stress treatments such as low temperature, NaCl, and ABA. Finally, the MdLTPG17 protein was shown to interact with the lysine-rich arabinogalactan protein MdAGP18 to perform its function in wax transport during plant growth and development.