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Kidney & Blood Pressure Research Jun 2024Patients with idiopathic membranous nephropathy (IMN) are particularly susceptible to thromboembolism (TE). The phospholipase A2 receptor (PLA2R) antibody (Ab) has been...
INTRODUCTION
Patients with idiopathic membranous nephropathy (IMN) are particularly susceptible to thromboembolism (TE). The phospholipase A2 receptor (PLA2R) antibody (Ab) has been indicated to work as an independent risk predictor for venous TE in IMN. This study aims to further explore the predictive value of PLA2R Ab for both venous and arterial TE in IMN patients.
METHODS
A total of 91 IMN patients were retrospectively selected and divided into anti-PLA2R-positive or -negative groups according to the anti-PLA2R Ab titer (cutoff: 20 RU/mL). Serum PLA2R Abs were estimated using ELISA. Anti-PLA2R-positive IMN patients were further assigned into two groups based on the presence or absence of TE.
RESULTS
Twelve (18.18%) IMN patients with anti-PLA2R positivity had TE, including both venous and arterial TE. No TE occurred in the anti-PLA2R-negative group. IMN patients in the anti-PLA2R-positive group had significantly higher levels of total cholesterol and low-density lipoprotein than those in the anti-PLA2R-negative group. No significant difference was observed in the anti-PLA2R Ab titer between patients with and without TE. Patients with TE were significantly older than those without TE.
CONCLUSION
This study demonstrates that the positive status of anti-PLA2R Abs contributes to thrombosis formation in IMN.
PubMed: 38865986
DOI: 10.1159/000539437 -
Biomarker Insights 2024Although, several studies have assessed the association of the phospholipase A2 receptor (PLA2R) and HLA-DQA1 SNPs with primary membranous nephropathy (PMN), results...
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 -values < .001. Moreover, the PLA2R-rs4664308/HLA-DQA1-rs2187668 interaction was significantly associated with an increased PMN risk, < .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], = .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.
PubMed: 38863528
DOI: 10.1177/11772719241259602 -
BMC Genomics Jun 2024Phospholipases constitute a diverse category of enzymes responsible for the breakdown of phospholipids. Their involvement in signal transduction with a pivotal role in...
BACKGROUND
Phospholipases constitute a diverse category of enzymes responsible for the breakdown of phospholipids. Their involvement in signal transduction with a pivotal role in plant development and stress responses is well documented.
RESULTS
In the present investigation, a thorough genome-wide analysis revealed that the pearl millet genome contains at least 44 phospholipase genes distributed across its 7 chromosomes, with chromosome one harbouring the highest number of these genes. The synteny analysis suggested a close genetic relationship of pearl millet phospholipases with that of foxtail millet and sorghum. All identified genes were examined to unravel their gene structures, protein attributes, cis-regulatory elements, and expression patterns in two pearl millet genotypes contrasting for rancidity. All the phospholipases have a high alpha-helix content and distorted regions within the predicted secondary structures. Moreover, many of these enzymes possess binding sites for both metal and non-metal ligands. Additionally, the putative promoter regions associated with these genes exhibit multiple copies of cis-elements specifically responsive to biotic and abiotic stress factors and signaling molecules. The transcriptional profiling of 44 phospholipase genes in two genotypes contrasting for rancidity across six key tissues during pearl millet growth revealed a predominant expression in grains, followed by seed coat and endosperm. Specifically, the genes PgPLD-alpha1-1, PgPLD-alpha1-5, PgPLD-delta1-7a, PgPLA1-II-1a, and PgPLD-delta1-2a exhibited notable expression in grains of both the genotypes while showing negligible expression in the other five tissues. The sequence alignment of putative promoters revealed several variations including SNPs and InDels. These variations resulted in modifications to the corresponding cis-acting elements, forming distinct transcription factor binding sites suggesting the transcriptional-level regulation for these five genes in pearl millet.
CONCLUSIONS
The current study utilized a genome-wide computational analysis to characterize the phospholipase gene family in pearl millet. A comprehensive expression profile of 44 phospholipases led to the identification of five grain-specific candidates. This underscores a potential role for at least these five genes in grain quality traits including the regulation of rancidity in pearl millet. Therefore, this study marks the first exploration highlighting the possible impact of phospholipases towards enhancing agronomic traits in pearl millet.
Topics: Pennisetum; Phospholipases; Multigene Family; Edible Grain; Gene Expression Regulation, Plant; Promoter Regions, Genetic; Phylogeny; Plant Proteins; Synteny; Gene Expression Profiling; Genotype; Chromosome Mapping
PubMed: 38858648
DOI: 10.1186/s12864-024-10504-x -
Journal of Lipid Research Jun 2024Bis(monoacylglycerol)phosphate (BMP) is an acidic glycerophospholipid localized to late endosomes and lysosomes. However, the metabolism of BMP is poorly understood....
Bis(monoacylglycerol)phosphate (BMP) is an acidic glycerophospholipid localized to late endosomes and lysosomes. However, the metabolism of BMP is poorly understood. Because many drugs that cause phospholipidosis inhibit lysosomal phospholipase A2 (LPLA2, PLA2G15, LYPLA3) activity, we investigated whether this enzyme has a role in BMP catabolism. The incubation of recombinant human LPLA2 (hLPLA2) and liposomes containing the naturally occurring BMP (sn-(2-oleoyl-3-hydroxy)-glycerol-1-phospho-sn-1'-(2'-oleoyl-3'-hydroxy)-glycerol (S,S-(2,2',C)-BMP) resulted in the deacylation of this BMP isomer. The deacylation rate was 70 times lower than that of dioleoyl phosphatidylglycerol (DOPG), an isomer and precursor of BMP. The release rates of oleic acid from DOPG and four BMP stereoisomers by LPLA2 differed. The rank order of the rates of hydrolysis were DOPG>S,S-(3,3',C)-BMP>R,S-(3,1',C)-BMP>R,R-(1,1',C)>S,S-(2,2')-BMP. The cationic amphiphilic drug amiodarone (AMD) inhibited the deacylation of DOPG and BMP isomers by hLPLA2 in a concentration dependent manner. Under these experimental conditions, the ICs of amiodarone-induced inhibition of the four BMP isomers and DOPG were less than 20 μM and approximately 30 μM, respectively. BMP accumulation was observed in AMD-treated RAW 264.7 cells. The accumulated BMP was significantly reduced by exogenous treatment of cells with active recombinant hLPLA2 but not with diisopropylfluorophosphate-inactivated recombinant hLPLA2. Finally, a series of cationic amphiphilic drugs known to cause phospholipidosis were screened for inhibition of LPLA2 activity as measured by either the transacylation or fatty acid hydrolysis of BMP or phosphatidylcholine as substrates. Fifteen compounds demonstrated significant inhibition with ICs ranging from 6.8 to 63.3 μM. These results indicate that LPLA2 degrades BMP isomers with different substrate specificities under acidic conditions and may be the key enzyme associated with BMP accumulation in drug-induced phospholipidosis.
PubMed: 38857781
DOI: 10.1016/j.jlr.2024.100574 -
The Journal of Cell Biology Sep 2024Sonic Hedgehog (SHH) is a driver of embryonic patterning that, when corrupted, triggers developmental disorders and cancers. SHH effector responses are organized through...
Sonic Hedgehog (SHH) is a driver of embryonic patterning that, when corrupted, triggers developmental disorders and cancers. SHH effector responses are organized through primary cilia (PC) that grow and retract with the cell cycle and in response to extracellular cues. Disruption of PC homeostasis corrupts SHH regulation, placing significant pressure on the pathway to maintain ciliary fitness. Mechanisms by which ciliary robustness is ensured in SHH-stimulated cells are not yet known. Herein, we reveal a crosstalk circuit induced by SHH activation of Phospholipase A2α that drives ciliary E-type prostanoid receptor 4 (EP4) signaling to ensure PC function and stabilize ciliary length. We demonstrate that blockade of SHH-EP4 crosstalk destabilizes PC cyclic AMP (cAMP) equilibrium, slows ciliary transport, reduces ciliary length, and attenuates SHH pathway induction. Accordingly, Ep4-/- mice display shortened neuroepithelial PC and altered SHH-dependent neuronal cell fate specification. Thus, SHH initiates coordination between distinct ciliary receptors to maintain PC function and length homeostasis for robust downstream signaling.
Topics: Animals; Mice; Cilia; Cyclic AMP; Hedgehog Proteins; Mice, Knockout; Prostaglandins; Receptors, Prostaglandin E, EP4 Subtype; Signal Transduction
PubMed: 38856684
DOI: 10.1083/jcb.202306002 -
Clinical Kidney Journal Jun 2024Phospholipase A2 receptor (PLA2R) is a major target antigen in idiopathic membranous nephropathy (MN). Anti-PLA2R antibodies are mainly of the immunoglobulin G (IgG)...
BACKGROUND
Phospholipase A2 receptor (PLA2R) is a major target antigen in idiopathic membranous nephropathy (MN). Anti-PLA2R antibodies are mainly of the immunoglobulin G (IgG) subclass IgG4, although other IgG subclass depositions in glomeruli may also be detected. However, the importance of the subclass of the IgG deposit has not been proven. Thus we investigated clinical findings from patients with idiopathic MN in relation to glomerular PLA2R deposition and IgG subclass.
METHODS
We enrolled 132 Japanese patients with biopsy-proven idiopathic MN in a multicentre retrospective observational study. We investigated the complete remission rate as the primary outcome and the development of end-stage kidney disease (ESKD) as the secondary outcome in relation to glomerular PLA2R deposition. Moreover, we evaluated prognostic factors, including glomerular IgG subclass, in the PLA2R-positive group.
RESULTS
The percentage of cases with glomerular PLA2R deposition was 76.5% ( = 101). The first complete remission rate of the PLA2R-positive group was worse than that of the PLA2R-negative group (logrank test < .001). ESKD incidence did not significantly differ between the glomerular PLA2R-negative and PLA2R-positive MN groups (logrank test = .608). In the PLA2R-positive group, higher PLA2R intensities and IgG2 staining were associated with a poorer first complete remission rate (logrank test < .001 and = .032, respectively). Cox proportional hazards analysis also showed that strong PLA2R deposition and positive IgG2 staining were significantly associated with a failure to reach complete remission [hazard ratio 2.09 ( = .004) and 1.78 ( = .030), respectively].
CONCLUSIONS
Our results suggest that intense glomerular PLA2R and IgG2 positivity predict a poor proteinuria remission rate in idiopathic MN.
PubMed: 38854426
DOI: 10.1093/ckj/sfae104 -
Journal of Extracellular Vesicles Jun 2024Migrasomes represent a recently uncovered category of extracellular microvesicles, spanning a diameter range of 500 to 3000 nm. They are emitted by migrating cells and...
Migrasomes represent a recently uncovered category of extracellular microvesicles, spanning a diameter range of 500 to 3000 nm. They are emitted by migrating cells and harbour a diverse array of RNAs and proteins. Migrasomes can be readily identified in bodily fluids like serum and urine, rendering them a valuable non-invasive source for disease diagnosis through liquid biopsy. In this investigation, we introduce a streamlined and effective approach for the capture and quantitative assessment of migrasomes, employing wheat germ agglutinin (WGA)-coated magnetic beads and flow cytometry (referred to as WBFC). Subsequently, we examined the levels of migrasomes in the urine of kidney disease (KD) patients with podocyte injury and healthy volunteers using WBFC. The outcomes unveiled a substantial increase in urinary podocyte-derived migrasome concentrations among individuals with KD with podocyte injury compared to the healthy counterparts. Notably, the urinary podocyte-derived migrasomes were found to express an abundant quantity of phospholipase A2 receptor (PLA2R) proteins. The presence of PLA2R proteins in these migrasomes holds promise for serving as a natural antigen for the quantification of autoantibodies against PLA2R in the serum of patients afflicted by membranous nephropathy. Consequently, our study not only pioneers a novel technique for the isolation and quantification of migrasomes but also underscores the potential of urinary migrasomes as a promising biomarker for the early diagnosis of KD with podocyte injury.
Topics: Podocytes; Humans; Cell-Derived Microparticles; Male; Female; Kidney Diseases; Flow Cytometry; Middle Aged; Adult; Biomarkers; Receptors, Phospholipase A2
PubMed: 38853287
DOI: 10.1002/jev2.12460 -
The Journal of Reproduction and... Jun 2024For the intracytoplasmic sperm injection (ICSI) procedure in pigs, an electrical pulse (EP) has been used as an effective method for oocyte stimulation, but unlike...
For the intracytoplasmic sperm injection (ICSI) procedure in pigs, an electrical pulse (EP) has been used as an effective method for oocyte stimulation, but unlike sperm, EP is unable to induce Ca oscillations. In this study, we investigated the effects of generating artificial Ca oscillations with phospholipase Cζ (PLCζ) mRNA, a candidate sperm factor, on fertilization, embryonic development, and gene expression after ICSI. Firstly, the concentration of PLCζ mRNA of a fixed volume (1.0 pl) that would induce a pattern of Ca rise similar to that of in vitro fertilized (IVF) sperm was examined and determined to be 300 ng/μl. Secondly, the effects of oocyte stimulation methods on fertilization and embryonic development were investigated. ICSI-oocytes were activated by EP (EP group) or by PLCζ mRNA (PLCζ group). Furthermore, IVF-oocytes (IVF group) and ICSI-oocytes with and without an injection of buffer (buffer and untreated groups, respectively) were used as controls. It was found that the rates of normal fertilization in the PLCζ and EP groups were significantly higher than those in the buffer and untreated groups. The blastocyst formation rates did not differ among the groups. The embryo quality in the EP group was inferior to those in the PLCζ and IVF groups. Additionally, the expression level of a proapoptosis-related gene (Caspase-3) in the EP group was significantly higher than those in the PLCζ and IVF groups. Our data suggest that oocyte activation by PLCζ mRNA has the effect of improving embryo quality.
PubMed: 38853022
DOI: 10.1262/jrd.2023-105 -
Nature Communications Jun 2024The I148M variant of PNPLA3 is closely associated with hepatic steatosis. Recent evidence indicates that the I148M mutant functions as an inhibitor of...
The I148M variant of PNPLA3 is closely associated with hepatic steatosis. Recent evidence indicates that the I148M mutant functions as an inhibitor of PNPLA2/ATGL-mediated lipolysis, leaving the role of wild-type PNPLA3 undefined. Despite showing a triglyceride hydrolase activity in vitro, PNPLA3 has yet to be established as a lipase in vivo. Here, we show that PNPLA3 preferentially hydrolyzes polyunsaturated triglycerides, mobilizing polyunsaturated fatty acids for phospholipid desaturation and enhancing hepatic secretion of triglyceride-rich lipoproteins. Under lipogenic conditions, mice with liver-specific knockout or acute knockdown of PNPLA3 exhibit aggravated liver steatosis and reduced plasma VLDL-triglyceride levels. Similarly, I148M-knockin mice show decreased hepatic triglyceride secretion during lipogenic stimulation. Our results highlight a specific context whereby the wild-type PNPLA3 facilitates the balance between hepatic triglyceride storage and secretion, and suggest the potential contribution of a loss-of-function by the I148M variant to the development of fatty liver disease in humans.
Topics: Animals; Lipase; Liver; Triglycerides; Mice; Lipoproteins, VLDL; Humans; Mice, Knockout; Fatty Acids, Unsaturated; Male; Fatty Liver; Mice, Inbred C57BL; Lipolysis; Membrane Proteins; Acyltransferases; Phospholipases A2, Calcium-Independent
PubMed: 38844467
DOI: 10.1038/s41467-024-49224-x -
Frontiers in Pharmacology 2024Treatment of glomerulonephritis presents several challenges, including limited therapeutic options, high costs, and potential adverse reactions. As a recognized Chinese... (Review)
Review
Treatment of glomerulonephritis presents several challenges, including limited therapeutic options, high costs, and potential adverse reactions. As a recognized Chinese patent medicine, poly-glycosides (TWP) have shown promising benefits in managing autoimmune diseases. To evaluate clinical effectiveness and safety of TWP in treating glomerulonephritis, we systematically searched PubMed, Cochrane Library, Web of Science, and Embase databases for controlled studies published up to 12 July 2023. We employed weighted mean difference and relative risk to analyze continuous and dichotomous outcomes. This meta-analysis included 16 studies that included primary membranous nephropathy (PMN), type 2 diabetic kidney disease (DKD), and Henoch-Schönlein purpura nephritis (HSPN). Analysis revealed that additional TWP administration improved patients' outcomes and total remission rates, reduced 24-h urine protein (24hUP) and decreased relapse events. The pooled results demonstrated the non-inferiority of TWP to glucocorticoids in achieving total remission, reducing 24hUP, and converting the phospholipase A2 receptor (PLA2R) status to negative. For DKD patients, TWP effectively reduced 24hUP levels, although it did not significantly improve the estimated glomerular filtration rate (eGFR). Compared to valsartan, TWP showed comparable improvements in 24hUP and eGFR levels. In severe cases of HSPN in children, significant clinical remission and a reduction in 24hUP levels were observed with the addition of TWP treatment. TWP did not significantly increase the incidence of adverse reactions. Therefore, TWP could offer therapeutic benefits to patients with PMN, DKD, and severe HSPN, with a minimal increase in the risk of side effects.
PubMed: 38841368
DOI: 10.3389/fphar.2024.1339153