The correlation between anti-phospholipase A2 receptor antibodies and hypercoagulability in patients with idiopathic membranous nephropathy.

BACKGROUND: Patients with idiopathic membranous nephropathy (IMN) are more likely to be complicated by venous thromboembolism (VTE). The aim of the study was to investigate the potential association between anti-phospholipase A2 receptor (PLA2R) antibodies and hypercoagulability in patients with IMN. METHODS: A total of 168 patients with biopsy-proven IMN and 36 patients with biopsy-proven minimal change disease (MCD) were enrolled in this study. The clinical data, serum anti-PLA2R antibodies and coagulation-related indices of the patients were retrospectively analyzed. RESULTS: Patients with IMN were categorized into glomerular PLA2R staining-positive (GAg+) IMN group and glomerular PLA2R staining-negative (GAg-) IMN group in the study. Patients with IMN who were GAg + had lower PT, APTT and R time than patients with IMN who were GAg-, while the CI value was higher in patients with IMN who were GAg+. Patients with IMN who were GAg + were divided into the SAb+/GAg + group and the SAb-/GAg + group. Patients with IMN who were SAb+/GAg + had higher Fib and MA values than patients with IMN who were SAb-/GAg+. Correlation analysis showed that serum anti-PLA2R antibodies were positively correlated with fibrinogen, D-dimer, K time, CI value, α-angle, and MA value. Multiple linear regression analysis indicated that anti-PLA2R antibodies were independently correlated with fibrinogen and MA value. CONCLUSION: Our study provides a new perspective on the underlying mechanisms of hypercoagulability in patients with IMN. Anti-PLA2R antibodies are associated with hypercoagulability in patients with IMN and may affect coagulation in patients with IMN by affecting platelet aggregation function and fibrinogen counts.

Conjugation with the Carrier Helped to Reveal acidification-Induced Structural Shift in the Peptide from Phospholipase Domain of Parvovirus B19.

Spectroscopic studies on domains and peptides of large proteins are complicated because of the tendency of short peptides to form oligomers in aquatic buffers, but conjugation of a peptide with a carrier protein may be helpful. In this study we approved that a fragment of SK30 peptide from phospholipase A2 domain of VP1 Parvovirus B19 capsid protein (residues: 144-159; 164; 171-183; sequence: SAVDSAARIHDFRYSQLAKLGINPYTHWTVADEELLKNIK) turns from random coil to alpha helix in the acidic medium only in case if it had been conjugated with BSA (through additional N-terminal Cys residue, turning it into CSK31 peptide, and SMCC linker) according to CD-spectroscopy results. In contrast, unconjugated SK30 peptide does not undergo such shift because it forms stable oligomers connected by intermolecular antiparallel beta sheet, according to IR-spectroscopy, CD-spectroscopy, blue native gel electrophoresis and centrifugal ultrafiltration, as, probably, the whole isolated phospholipase domain of VP1 protein does. However, being a part of the long VP1 capsid protein, phospholipase domain may change its fold during the acidification of the medium in the endolysosome by the way of the formation of contacts between protonated His153 and Asp175, promoting the shift from random coil to alpha helix in its N-terminal part. This study opens up a perspective of vaccine development, since rabbit polyclonal antibodies against the conjugate of CSK31 peptide with BSA, in which the structure of the second alpha helix from the phospholipase A2 domain should be reproduced, can bind epitopes of the complete recombinant unique part of VP1 Parvovirus B19 capsid (residues: 1-227).

The joint association of lipoprotein(a) and Lp-PLA2 with the risk of stroke recurrence.

BACKGROUND AND PURPOSE: Currently little is known about the joint association of lipoprotein (a) [Lp(a)] and Lipoprotein-associated phospholipase A2 (Lp-PLA2) with stroke recurrence. METHODS: In this prospective multicenter cohort study, 10,675 consecutive acute ischemic stroke (IS) and transient ischemic attack patients (TIA) with Lp(a) and Lp-PLA2 were enrolled. The association of stroke recurrence within 1 year with Lp(a) and Lp-PLA2 was assessed using Cox proportional hazards models and Kaplan-Meier curves. The interaction between Lp(a) and Lp-PLA2 with stroke recurrence was evaluated by multiplicative and additive scales. RESULTS: A significant joint association of Lp(a) and Lp-PLA2 with the risk of stroke recurrence was observed. Multivariate cox regression analysis demonstrated that the combination of elevated Lp(a) (≥ 50 mg/dL) and Lp-PLA2 (≥175.1 ng/ml) was independently associated with the risk of stroke recurrence (adjusted hazard ratio: 1.42; 95 % CI: 1.15-1.76). Both significant multiplicative [(exp(ß3):1.63, 95 % CI: 1.17-2.29, P = 0.004] and additive interaction (RERI:0.55, 95 % CI: 0.20-0.90, P = 0.002; AP: 0.39, 95 %CI, 0.24-0.53) were observed between Lp(a) and Lp-PLA2. CONCLUSIONS: Our results indicated that Lp(a) and Lp-PLA2 have a joint association with the risk of stroke recurrence in IS/TIA patients. Patients with concomitant presence of elevated Lp(a) and Lp-PLA2 have greater risk of stroke recurrence.

Lipopolysaccharide (LPS)-induced inflammation in RAW264.7 cells is inhibited by microRNA-494-3p via targeting lipoprotein-associated phospholipase A2.

BACKGROUND: Gram-negative bacterial lipopolysaccharide (LPS) is a major component of inflammation and plays a key role in the pathogenesis of sepsis. According to our previous study, the expression of lipoprotein-associated phospholipase A2 (Lp-PLA2) is significantly upregulated in septic patients and is positively correlated with the severity of this disease. Herein, we investigated the potential roles of Lp-PLA2-targeting microRNAs (miRNAs) in LPS-induced inflammation in murine mononuclear macrophages (RAW264.7 cells). METHODS: In LPS-stimulated RAW264.7 cells, Lp-PLA2 was confirmed to be expressed during the inflammatory response. The function of microRNA-494-3p (miR-494-3p) in the LPS-induced inflammatory response of RAW264.7 cells was determined by the transfection of a miR-494-3p mimic or inhibitor in vitro. RESULTS: Compared to the control, LPS induced a significant increase in the Lp-PLA2 level, which was accompanied by the release of inflammatory mediators. The bioinformatics and qRT‒PCR results indicated that the miR-494-3p level was associated with Lp-PLA2 expression in the LPS-induced inflammatory response of RAW264.7 cells. Dual-luciferase reporter assay results confirmed that the 3'-UTR of Lp-PLA2 was a functional target of microRNA-494-3p. During the LPS-induced inflammatory response of RAW264.7 cells, targeting Lp-PLA2 and transfecting miR-494-3p mimics significantly upregulated the expression of miR-494-3p, leading to a reduction in the release of inflammatory factors and conferring a protective effect on LPS-stimulated RAW264.7 cells. CONCLUSION: By targeting Lp-PLA2, miR-494-3p suppresses Lp-PLA2 secretion, thereby alleviating LPS-induced inflammation, which indicates that miR-494-3p may be a potential target for sepsis treatment.

Correlation between lipoprotein-associated phospholipase A2 and poststroke mild cognitive impairment.

OBJECTIVES: This study aimed to investigate the correlation between serum lipoprotein-associated phospholipase A2 (Lp-PLA2) and poststroke mild cognitive impairment (PSMCI). METHODS: The patients included in the study were divided into PSMCI (68 cases) and cognitively normal (CN) (218 cases) groups and followed up for six months. Demographic and clinical data were collected. A logistic regression analysis was performed to determine whether Lp-PLA2 is an independent risk factor for PSMCI. Spearman's correlation analysis was used to examine the correlation between Lp-PLA2 levels and Montreal Cognitive Assessment (MoCA) scores. A receiver operating characteristic (ROC) curve analysis was performed to determine the diagnostic threshold value of Lp-PLA2 for PSMCI. RESULTS: Serum Lp-PLA2 levels were significantly higher in the PSMCI group than in the CN group. The logistic regression analysis showed that Lp-PLA2 was an independent risk factor for PSMCI (OR = 1.05, 95% CI = 1.03-1.07). Spearman's correlation analysis revealed a significant correlation between the Lp-PLA2 levels and MoCA scores (R = -0.49). The area under the ROC curve for Lp-PLA2 was 0.849, and the threshold value for PSMCI occurrence was 236.8 ng/ml. CONCLUSIONS: Elevated serum Lp-PLA2 is an independent risk factor for PSMCI and may serve as a potential biomarker for PSMCI.

Secretory Phospholipase A2 Levels Are High in Women with Sickle Cell Disease and Menstruation-Induced Vaso-Occlusive Crises.

Menstruation-induced vaso-occlusive crisis (MIVOC) is a significant cause of morbidity in women with sickle cell disease (SCD). Secretory phospholipase A2 (sPLA2) is an inflammatory biomarker that is elevated in vaso-occlusive events such as acute chest syndrome (ACS), but its role in MIVOC is not previously studied. This study compared the serum level of sPLA2 among women with MIVOC and those without MIVOC. This is a comparative cross-sectional study. 354 women with SCD were screened for MIVOC using a structured questionnaire. sPLA2 levels were assayed using a standard ELISA while full blood counts were performed on an automated hematology analyzer. Data were analyzed using the SPSS software v26.0. Results were summarized as frequencies, percentages, and mean ± standard deviation. Variables were compared using the Student's t-test and Pearson's correlation. A p-value of <.05 was considered significant. The prevalence of MIVOC was 26.8%. Participants with MIVOC (n = 95) had significantly lower mean hemoglobin concentration (8.00 ± 2.03g/dL vs. 9.95 ± 4.15g/dL, p < .000), significantly higher mean platelets count (518.71 ± 84.58 × 109/L vs 322.21 ± 63.80 × 109/L, p < .000) and higher sPLA2 level (6.58 ± 1.94 IU vs 6.03 ± 0.42 IU, p = .008) compared to those without MIVOC (n = 95). Among participants with MIVOC, sPLA2 levels positively correlated with total white blood cell, absolute neutrophil, and lymphocyte counts. This study demonstrates that MIVOC is common among women with SCD and that the pathophysiology of MIVOC may have an inflammatory basis similar to that of ACS. The potential role of anti-inflammatory and antiplatelet agents in preventing and treating MIVOC may be explored.

Contribution of transient receptor potential vanilloid 1 (TRPV1) channel to cholinergic contraction of rat bladder smooth muscle.

Transient receptor potential vanilloid 1 (TRPV1) is a calcium-permeable ion channel that is gated by the pungent constituent of red chili pepper, capsaicin, and by related chemicals from the group of vanilloids, in addition to noxious heat. It is expressed mostly in sensory neurons to act as a detector of painful stimuli produced by pungent chemicals and high temperatures. Although TRPV1 is also found outside the sensory nervous system, its expression and function in the bladder detrusor smooth muscle (DSM) remain controversial. Here, by using Ca2+ imaging and patch clamp on isolated rat DSM cells, in addition to tensiometry on multicellular DSM strips, we show that TRPV1 is expressed functionally in only a fraction of DSM cells, in which it acts as an endoplasmic reticulum Ca2+-release channel responsible for the capsaicin-activated [Ca2+]i rise. Carbachol-stimulated contractions of multicellular DSM strips contain a TRPV1-dependent component, which is negligible in the circular DSM but reaches ≤50% in the longitudinal DSM. Activation of TRPV1 in rat DSM during muscarinic cholinergic stimulation is ensured by phospholipase A2-catalysed derivation of arachidonic acid and its conversion by lipoxygenases to eicosanoids, which act as endogenous TRPV1 agonists. Immunofluorescence detection of TRPV1 protein in bladder sections and isolated DSM cells confirmed both its preferential expression in the longitudinal DSM sublayer and its targeting to the endoplasmic reticulum. We conclude that TRPV1 is an essential contributor to the cholinergic contraction of bladder longitudinal DSM, which might be important for producing spatial and/or temporal anisotropy of bladder wall deformation in different regions during parasympathetic stimulation. KEY POINTS: The transient receptor potential vanilloid 1 (TRPV1) heat/capsaicin receptor/channel is localized in the endoplasmic reticulum membrane of detrusor smooth muscle (DSM) cells of the rat bladder, operating as a calcium-release channel. Isolated DSM cells are separated into two nearly equal groups, within which the cells either show or do not show TRPV1-dependent [Ca2+]i rise. Carbachol-stimulated, muscarinic ACh receptor-mediated contractions of multicellular DSM strips contain a TRPV1-dependent component. This component is negligible in the circular DSM but reaches ≤50% in longitudinal DSM. Activation of TRPV1 in rat DSM during cholinergic stimulation involves phospholipase A2-catalysed derivation of arachidonic acid and its conversion by lipoxygenases to eicosanoids, which act as endogenous TRPV1 agonists.

Differentiating human phospholipase A2's activity toward phosphatidylinositol, phosphatidylinositol phosphate and phosphatidylinositol bisphosphate.

Phospholipase A2's (PLA2's) constitute a superfamily of enzymes that hydrolyze the sn-2 fatty acyl chain on glycerophospholipids. We have previously reported that each PLA2 Type shows a unique substrate specificity for the molecular species it hydrolyzes, especially the acyl chain that is cleaved from the sn-2 position and to some extent the polar group. However, phosphatidylinositol (PI) and PI phosphates (PIPs) have not been as well studied as substrates as other phospholipids because the PIPs require adaptation of the standard analysis methods, but they are important in vivo. We determined the in vitro activity of the three major types of human PLA2's, namely the cytosolic (c), calcium-independent (i), and secreted (s) PLA2's toward PI, PI-4-phosphate (PI(4)P), and PI-4,5-bisphosphate (PI(4,5)P2). The in vitro assay revealed that Group IVA cPLA2 (GIVA cPLA2) showed relatively high activity toward PI and PI(4)P among the tested PLA2's; nevertheless, the highly hydrophilic headgroup disrupted the interaction between the lipid surface and the enzyme. GIVA cPLA2 and GVIA iPLA2 showed detectable activity toward PI(4,5)P2, but it appeared to be a poorer substrate for all of the PLA2's tested. Furthermore, molecular dynamics (MD) simulations demonstrated that Thr416 and Glu418 of GIVA cPLA2 contribute significantly to accommodating the hydrophilic head groups of PI and PI(4)P, which could explain some selectivity for PI and PI(4)P. These results indicated that GIVA cPLA2 can accommodate PI and PI(4)P in its active site and hydrolyze them, suggesting that the GIVA cPLA2 may best account for the PI and PIP hydrolysis in living cells.

Specific Amino Acid Residues in the Three Loops of Snake Cytotoxins Determine Their Membrane Activity and Provide a Rationale for a New Classification of These Toxins.

Cytotoxins (CTs) are three-finger membrane-active toxins present mainly in cobra venom. Our analysis of the available CT amino acid sequences, literature data on their membrane activity, and conformational equilibria in aqueous solution and detergent micelles allowed us to identify specific amino acid residues which interfere with CT incorporation into membranes. They include Pro9, Ser28, and Asn/Asp45 within the N-terminal, central, and C-terminal loops, respectively. There is a hierarchy in the effect of these residues on membrane activity: Pro9 > Ser28 > Asn/Asp45. Taking into account all the possible combinations of special residues, we propose to divide CTs into eight groups. Group 1 includes toxins containing all of the above residues. Their representatives demonstrated the lowest membrane activity. Group 8 combines CTs that lack these residues. For the toxins from this group, the greatest membrane activity was observed. We predict that when solely membrane activity determines the cytotoxic effects, the activity of CTs from a group with a higher number should exceed that of CTs from a group with a lower number. This classification is supported by the available data on the cytotoxicity and membranotropic properties of CTs. We hypothesize that the special amino acid residues within the loops of the CT molecule may indicate their involvement in the interaction with non-lipid targets.

Rapid Movement of Palmitoleic Acid from Phosphatidylcholine to Phosphatidylinositol in Activated Human Monocytes.

This work describes a novel route for phospholipid fatty acid remodeling involving the monounsaturated fatty acid palmitoleic acid. When administered to human monocytes, palmitoleic acid rapidly incorporates into membrane phospholipids, notably into phosphatidylcholine (PC). In resting cells, palmitoleic acid remains within the phospholipid pools where it was initially incorporated, showing no further movement. However, stimulation of the human monocytes with either receptor-directed (opsonized zymosan) or soluble (calcium ionophore A23187) agonists results in the rapid transfer of palmitoleic acid moieties from PC to phosphatidylinositol (PI). This is due to the activation of a coenzyme A-dependent remodeling route involving two different phospholipase A2 enzymes that act on different substrates to generate free palmitoleic acid and lysoPI acceptors. The stimulated enrichment of specific PI molecular species with palmitoleic acid unveils a hitherto-unrecognized pathway for lipid turnover in human monocytes which may play a role in regulating lipid signaling during innate immune activation.

Association of 10 Polymorphisms in PLA2R1 and HLA DQA1 Genes with Primary Membranous Nephropathy Risk: A Meta-Analysis and a Meta-Regression.

Background: Although, several studies have assessed the association of the phospholipase A2 receptor (PLA2R) and HLA-DQA1 SNPs with primary membranous nephropathy (PMN), results were inconsistent and between-studies heterogeneity needs to be investigated. Objectives: The aim of this review was to summarize existing data on the contribution of 10 SNPs in the PLA2R and HLA-DQA1 genes to PMN susceptibility and to investigate the between-studies heterogeneity by subgroup analyses and meta-regressions. Design: This study was performed according to the PRISMA guidelines for systematic reviews and meta-analyses. Data sources and methods: An electronic literature search for eligible studies among all papers published prior to January 10, 2024, was conducted through PubMed, EMBASE, Web of science and Scopus databases. Meta-analyses together with subgroup analyses and meta-regressions were performed for the 10 following SNPs: rs4664308, rs3749117, rs3749119, rs35771982, rs3828323, rs16844715, rs1511223, rs6757188, rs2715918, and rs2187668. Results: Combined analyses revealed a significant increase in PMN risk conferred by the following alleles: rs4664308*A, rs3749117*T, rs3749119*C, rs35771982*G, rs3828323*C, rs16844715*C, rs1511223*A, rs2715918*A, and rs2187668*A, all P-values < .001. Moreover, the PLA2R-rs4664308/HLA-DQA1-rs2187668 interaction was significantly associated with an increased PMN risk, P < .001. However, there was a substantial between-studies heterogeneity for some SNPs. Subgroup analyses by ethnicity for the 9 PLA2R SNPs did not show any cross-ethnic disparity. Inversely, the risk conferred by the HLA-DQA1 rs2187668*A allele was significantly higher in Caucasians (OR [95% CI] = 3.929 [3.251-4.748]) than in Asians (OR [95% CI] = 2.537 [1.94-3.318], P = .007. Besides, meta-regressions revealed for the majority of investigated SNPs significant correlations of the effect size with albumin, 24-hours proteinuria, serum creatinine, and eGFR levels. Hence, the influence on PMN risk conferred by the PLA2R and HLA-DQA1 SNPs was rather noted in patients with a severe disease. Conclusion: This meta-analysis showed that 9 out of the 10 investigated SNPs in PLA2R and HLA-DQA1 genes were associated with increased PMN risk. Heterogeneity could be due to disparate patient groups in terms of disease presentation for almost all SNPs, and ethnicity for the HLA-DQA1 rs2187668 SNP. Registration: This review has been registered on PROSPERO: CRD42024506729. Available from: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024506729.

Genetic factors in primary membranous nephritis Why was the study done? Primary membranous nephritis (PMN) is the most common etiology of adult-onset nephrotic syndrome. Understanding risk factors, particularly genetic ones, would provide a better understanding of its pathophysiological mechanisms in order to prevent and treat patients more effectively. What did the researchers do? The research team summarized published data on genetic factors associated with PMN including phospholipase A2 receptor (PLA2R) and HLA-DQA1 genes. What did the researchers find? The total number of included studies was 27. Nine out of ten genetic factors were found to be associated with PMN risk. Moreover, we noted significant interaction between PLA2R and HLA-DQA1 in potentializing PMN risk. Nevertheless, there was a significant between-studies heterogeneity which was found to be explained in part by disease severity. What do the findings mean? This study has identified some important some genetic factors associated with PMN together with confounding factors that could influence the aforementioned association.

Trypanosoma cruzi infection modulates secreted phospholipase A2 expression in the salivary glands of Rhodnius prolixus.

Phospholipases A2 (PLA2) comprise a superfamily of enzymes that specifically catalyze hydrolysis of the ester bond at the sn-2 position of glycerophospholipids, generating lysophospholipids and fatty acids. In Rhodnius prolixus, one of the main vectors of the Chagas's disease etiologic agent Trypanosoma cruzi, it was previously shown that lysophosphatidylcholine, a bioactive lipid, found in the insect's saliva, contributes to the inhibition of platelet aggregation, and increases the production of nitric oxide, an important vasodilator. Due to its role in potentially generating LPC, here we studied the PLA2 present in the salivary glands of R. prolixus. PLA2 activity is approximately 100 times greater in the epithelium than in the contents of salivary glands. Our study reveals the role of the RpPLA2XIIA gene in the insect feeding performance and in the fatty acids composition of phospholipids extracted from the salivary glands. Knockdown of RpPLA2XIIA significantly altered the relative amounts of palmitic, palmitoleic, oleic and linoleic acids. A short-term decrease in the expression of RpPLA2III and RpPLA2XIIA in the salivary glands of R. prolixus was evident on the third day after infection by T. cruzi. Taken together, our results contribute to the understanding of the role of PLA2 in the salivary glands of hematophagous insects and show that the parasite is capable of modulating even tissues that are not colonized by it.

Backbone NMR resonance assignments for the VP1u N-terminal receptor-binding domain of the human parvovirus pathogen B19.

Parvovirus B19 (B19V) is a human pathogen that is the causative agent of several diseases in infants and adults. Due to a lack of antivirals against this virus, treatment options are limited. The minor capsid protein of B19V has a unique N terminus, named VP1u, which is essential for infection. The VP1u encodes a receptor binding domain (RBD), necessary for host cell entry, and a phospholipase A2 (PLA2) domain, crucial for endosomal escape during cellular trafficking. Both domains are indispensable for infection, making the RBD a plausible drug target for inhibitors against B19V, as it is located on the exterior surface of the virus. To date, no experimental structural information has been available for the VP1u component for any Parvovirus. Here we report the backbone NMR resonance assignments for the RBD of B19V and demonstrate it forms a stable structure. The backbone chemical shifts are in good agreement with a structure predicted by AlphaFold, validating that the RBD contains three helices connected by tight turns. This RBD construct can now be used for further NMR studies, including assignment of full-length VP1u, determination of protein-protein interaction interfaces, and development of B19 antivirals specific to the RBD domain. Database: BMRB submission code: 52440.

Backbone NMR resonance assignments for the VP1u N-terminal receptor-binding domain of the human parvovirus pathogen B19.

Parvovirus B19 (B19V) is a human pathogen that is the causative agent of several diseases in infants and adults. Due to a lack of antivirals against this virus, treatment options are limited. The minor capsid protein of B19V has a unique N terminus, named VP1u, which is essential for infection. The VP1u encodes a receptor binding domain (RBD), necessary for host cell entry, and a phospholipase A2 (PLA2) domain, crucial for endosomal escape during cellular trafficking. Both domains are indispensable for infection, making the RBD a plausible drug target for inhibitors against B19V, as it is located on the exterior surface of the virus. To date, no experimental structural information has been available for the VP1u component for any Parvovirus. Here we report the backbone NMR resonance assignments for the RBD of B19V and demonstrate it forms a stable structure. The backbone chemical shifts are in good agreement with a structure predicted by AlphaFold, validating that the RBD contains three helices connected by tight turns. This RBD construct can now be used for further NMR studies, including assignment of full-length VP1u, determination of protein-protein interaction interfaces, and development of B19 antivirals specific to the RBD domain.

Combining Anti-Mitochondrial Antibodies, Anti-Histone, and PLA2/COX Biomarkers to Increase Their Diagnostic Accuracy for Autism Spectrum Disorders.

BACKGROUND: Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impairments in social interaction and restricted and repetitive behaviors. Oxidative stress may be a critical link between mitochondrial dysfunction and ASD as reactive oxygen species (ROS) generated from pro-oxidant environmental toxicants and activated immune cells can result in mitochondrial failure. Recently, mitochondrial dysfunction, autoimmunity, and abnormal lipid mediators have been identified in multiple investigations as an acknowledged etiological mechanism of ASD that can be targeted for therapeutic intervention. METHODS: The relationship between lipid mediator markers linked to inflammation induction, such as phospholipase A2/cyclooxygenase-2 (PLA2/Cox-2), and the mitochondrial dysfunction marker anti-mitochondrial antibodies (AMA-M2), and anti-histone autoantibodies in the etiology of ASD was investigated in this study using combined receiver operating characteristic (ROC) curve analyses. This study also sought to identify the linear combination for a given set of markers that optimizes the partial area under ROC curves. This study included 40 age- and sex-matched controls and 40 ASD youngsters. The plasma of both groups was tested for PLA2/COX-2, AMA-M2, and anti-histone autoantibodies' levels using ELISA kits. ROC curves and logistic regression models were used in the statistical analysis. RESULTS: Using the integrated ROC curve analysis, a notable rise in the area under the curve was noticed. Additionally, the combined markers had markedly improved specificity and sensitivity. CONCLUSIONS: The current study suggested that measuring the predictive value of selected biomarkers related to mitochondrial dysfunction, autoimmunity, and lipid metabolism in children with ASD using a ROC curve analysis could lead to a better understanding of the etiological mechanism of ASD as well as its relationship with metabolism.

The relationships between biological novel biomarkers Lp-PLA2 and CTRP-3 and CVD in patients with type 2 diabetes mellitus.

BACKGROUND: Cardiovascular disease (CVD) is recognized as a primary and severe comorbidity in patients with type 2 diabetes mellitus (T2DM) and is also identified as a leading cause of mortality within this population. Consequently, the identification of novel biomarkers for the risk stratification and progression of CVD in individuals with T2DM is of critical importance. METHODS: This retrospective cohort study encompassed 979 patients diagnosed with T2DM, of whom 116 experienced CVD events during the follow-up period. Clinical assessments and comprehensive blood laboratory analyses were conducted. Age- and sex-adjusted Cox proportional hazard regression analysis was utilized to evaluate the association between lipoprotein-associated phospholipase A2 (Lp-PLA2), C1q/tumor necrosis factor-related protein 3 (CTRP-3), and the incidence of CVD in T2DM. The diagnostic performance of these biomarkers was assessed through receiver operating characteristic (ROC) curve analysis and the computation of the area under the curve (AUC). RESULTS: Over a median follow-up of 84 months (interquartile range: 42 [32-54] months), both novel inflammatory markers, Lp-PLA2 and CTRP-3, and traditional lipid indices, such as low-density lipoprotein cholesterol and apolipoprotein B, exhibited aberrant expression in the CVD-afflicted subset of the T2DM cohort. Age- and sex-adjusted Cox regression analysis delineated that Lp-PLA2 (hazard ratio [HR] = 1.007 [95% confidence interval {CI}: 1.005-1.009], p < 0.001) and CTRP-3 (HR = 0.943 [95% CI: 0.935-0.954], p < 0.001) were independently associated with the manifestation of CVD in T2DM. ROC curve analysis indicated a substantial predictive capacity for Lp-PLA2 (AUC = 0.81 [95% CI: 0.77-0.85], p < 0.001) and CTRP-3 (AUC = 0.91 [95% CI: 0.89-0.93], p < 0.001) in forecasting CVD occurrence in T2DM. The combined biomarker approach yielded an AUC of 0.94 (95% CI: 0.93-0.96), p < 0.001, indicating enhanced diagnostic accuracy. CONCLUSIONS: The findings suggest that the biomarkers Lp-PLA2 and CTRP-3 are dysregulated in patients with T2DM who develop CVD and that each biomarker is independently associated with the occurrence of CVD. The combined assessment of Lp-PLA2 and CTRP-3 may significantly augment the diagnostic precision for CVD in the T2DM demographic.

Fibrinogen-albumin ratio predicts treatment response in phospholipase A2 receptor-associated membranous nephropathy with nephrotic syndrome.

BACKGROUND: The M-type phospholipase A2 receptor (PLA2R)-associated primary membranous nephropathy (PMN) is an immune-related disease in adults with increasing morbidity and variable treatment response, in which inflammation may contribute to the multifactorial immunopathogenesis. The relationship between fibrinogen-albumin ratio (FAR), serving as a novel inflammatory biomarker, and PMN is still unclear. Therefore, this study aims to clarify the association between FAR and disease activity and therapy response of PMN. METHODS: 110 biopsy-proven phospholipase A2 receptor (PLA2R) -associated PMN participants with nephrotic syndrome from January 2017 to December 2021 were recruited in the First Affiliated Hospital of Nanjing Medical University. The independent risk factors of non-remission (NR) and the predictive ability of FAR were explored by Cox regression and receiver-operating characteristic (ROC) curve analysis. According to the optimal cutoff value, study patients were categorized into the low-FAR group (≤the cutoff value) and the high-FAR group (>the cutoff value). Spearman's correlations were used to examine the associations between FAR and baseline clinicopathological characteristics. Kaplan-Meier method was used to assess the effects of FAR on remission. RESULTS: In the entire study cohort, 78 (70.9%) patients reached complete or partial remission (CR or PR). The optimal cutoff value of FAR for predicting the remission outcome (CR + PR) was 0.233. The Kaplan-Meier survival analysis demonstrated that the high-FAR group (>0.233) had a significantly lower probability to achieve CR or PR compared to the low-FAR group (≤0.233) (Log Rank test, p = 0.021). Higher levels of FAR were identified as an independent risk factor for NR, and the high-FAR group was associated with a 2.27 times higher likelihood of NR than the low-FAR group (HR 2.27, 95% CI 1.01, 5.13, p = 0.048). These relationships remained robust with further analysis among calcineurin inhibitors (CNIs)-receivers. In the multivariate Cox regression model, the incidence of NR was 4.00 times higher in the high-FAR group than in the low-FAR group (HR 4.00, 95% CI 1.41, 11.31, p = 0.009). Moreover, ROC analysis revealed the predictive value of FAR for CR or PR with a 0.738 area under curve (AUC), and the AUC of anti-PLA2R Ab was 0.675. When combining FAR and anti-PLA2R Ab, the AUC was boosted to 0.766. CONCLUSIONS: FAR was significantly correlated with proteinuria and anti-PLA2R Ab in PMN. As an independent risk factor for NR, FAR might serve as a potential inflammation-based prognostic tool for identifying cases with poor treatment response, and the best predictive cutoff value for outcomes was 0.233.

The Prevalence, Characteristics, and Putative Mechanisms of Dual Antigen-Positive Membranous Nephropathy: The Underestimated Condition.

Following the discovery of podocyte phospholipase A2 receptor and thrombospondin type-1 domain-containing 7A, various potential target antigens for membranous nephropathy (MN) have been reported one after another. MN target antigens have now been identified in a significant proportion of patients, and a new classification framework classifies patients with MN based on the detected antigen and associated disease phenotype. A serology-based approach that does not require a histological diagnosis for patients suspected of having MN has also been proposed. However, there have been cases in which dual positivity for MN antigens and/or corresponding antibodies has been shown. Importantly, some of them showed a transition of the affected patient's immune responses to MN antigens, suggesting that serological diagnosis changes depending on the timing of the analysis. In this review, we provide detailed information on these cases and present an overview of our recent understanding of their putative mechanisms involved in these cases. Greater awareness is required to adequately recognize and develop appropriate therapeutic strategies for this condition.

Bee venom as a promising therapeutic strategy in central nervous system diseases.

Central nervous system (CNS) disorders are one of the leading health problems today, accounting for a large proportion of global morbidity and mortality. Most these disorders are characterized by high levels of oxidative stress and intense inflammatory responses in degenerated neuronal tissues. While extensive research has been conducted on CNS diseases, but few breakthroughs have been made in treatment methods. To date, there are no disease-modifying drugs available for CNS treatment, underscoring the urgent need for finding effective medications. Bee venom (BV), which is produced by honeybee workers' stingers, has been a subject of interest and study across various cultures. Over the past few decades, extensive research has focused on BV and its therapeutic potentials. BV consists a variety of substances, mainly proteins and peptides like melittin and phospholipase A2 (PLA2). Research has proven that BV is effective in various medical conditions, including pain, arthritis and inflammation and CNS disorders such as Multiple sclerosis, Alzheimer's disease and Parkinson's disease. This review provides a comprehensive overview of the existing knowledge concerning the therapeutic effects of BV and its primary compounds on various CNS diseases. Additionally, we aim to shed light on the potential cellular and molecular mechanisms underlying these effects.

Comparative electrophysiological characterization of ammodytoxin A, a ß-neurotoxin from the nose-horned viper venom, and its enzymatically inactive mutant.

Presynaptic- or ß-neurotoxicity of secreted phospholipases A2 (sPLA2) is a complex process. For full expression of ß-neurotoxicity, the enzymatic activity of the toxin is essential. However, it has been shown that not all toxic effects of a ß-neurotoxin depend on its enzymatic activity, for example, the inhibition of mitochondrial cytochrome c oxidase. The main objective of this study was to verify whether it is possible to observe and study the phospholipase-independent actions of ß-neurotoxins by a standard ex vivo twitch-tension experimental approach. To this end, we compared the effects of a potent snake venom ß-neurotoxin, ammodytoxin A (AtxA), and its enzymatically inactive mutant AtxA(D49S) on muscle contraction of the mouse phrenic nerve-hemidiaphragm preparation. While AtxA significantly affected the amplitude of the indirectly evoked isometric muscle contraction, the resting tension of the neuromuscular (NM) preparation, the amplitude of the end-plate potential (EPP), the EPP half decay time and the resting membrane potential, AtxA(D49S) without enzymatic activity did not. From this, we can conclude that the effects of AtxA independent of enzymatic activity cannot be studied with classical electrophysiological measurements on the isolated NM preparation. Our results also suggest that the inhibition of cytochrome c oxidase activity by AtxA is not involved in the rapid NM blockade by this ß-neurotoxin, but that its pathological consequences are rather long-term. Interestingly, in our experimental setup, AtxA upon direct stimulation reduced the amplitude of muscle contraction and induced contracture of the hemidiaphragm, effects that could be interpreted as myotoxic.