Phospholipase D regulates ferroptosis signal transduction in mouse spleen hypoxia response

High-altitude hypoxia exposure can lead to phospholipase D-mediated lipid metabolism disorder in spleen tissues and induce ferroptosis. Nonetheless, the key genes underlying hypoxia-induced splenic phospholipase D and the ferroptosis pathway remain unclear. This study aimed to establish a hypoxia animal model. Combined transcriptomic and proteomic analyses showed that 95 predicted target genes (proteins) were significantly differentially expressed under hypoxic conditions. Key genes in phospholipase D and ferroptosis pathways under hypoxic exposure were identified by combining Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis techniques. Gene set enrichment analysis (GSEA) showed that the differential gene sets of the phospholipase D and ferroptosis signaling pathways were upregulated in the high-altitude hypoxia group. The genes in the phospholipase D signalling pathway were verified, and the expression levels of KIT and DGKG were upregulated in spleen tissues under hypoxic exposure. Subsequently, the mRNA and protein expression levels of genes from the exogenous pathway such as TFRC, SLC40A1, SLC7A11, TRP53, and FTH1 and those from the endogenous pathway such as GPX4, HMOX1, and ALOX15 differentials in the ferroptosis signalling pathway were verified, and the results indicated significant differential expression. In summary, exposure to high-altitude hypoxia mediated phospholipid metabolism disturbance through the phospholipase D signalling pathway and further induced ferroptosis, leading to splenic injury.

An overview of some enzymes from buthid scorpion venoms from Colombia: Centruroides margaritatus, Tityus pachyurus, and Tityus n. sp. aff. metuendus

Background: In Colombia, several species of Buthidae scorpions belonging to the genera Centruroides and Tityus coexist, and their stings are considered life-threatening to humans because of their venom neurotoxins. Despite previous studies focusing on neurotoxins from these scorpion genera, little is known about the enzymes present in their venoms and their relationship with whole venom toxicity. Methods: Here, using proteomic and biochemical protocols the enzymatic activities of the venoms of three Colombian scorpion species, C. margaritatus, T. pachyurus, and T. n. sp. aff. metuendus, were compared to establish the presence and absence of enzymes such as phospholipases, hyaluronidases, and proteases that could be related to venom toxicity. Results: C. margaritatus was positive for hyaluronidases, T. n. sp. aff. metuendus for proteases, and T. pachyurus exhibited activity for all three mentioned enzymes. Conclusion: This information provides valuable insights into the specific enzyme diversity of each species' venom and their potential role in venom toxicity, which could contribute to the development of better treatments and prevention strategies for scorpion envenomation.

Understanding the complexity of Tityus serrulatus venom: A focus on high molecular weight components

Tityus serrulatus scorpion is responsible for a significant number of envenomings in Brazil, ranging from mild to severe, and in some cases, leading to fatalities. While supportive care is the primary treatment modality, moderate and severe cases require antivenom administration despite potential limitations and adverse effects. The remarkable proliferation of T. serrulatus scorpions, attributed to their biology and asexual reproduction, contributes to a high incidence of envenomation. T. serrulatus scorpion venom predominantly consists of short proteins acting as neurotoxins (α and ß), that primarily target ion channels. Nevertheless, high molecular weight compounds, including metalloproteases, serine proteases, phospholipases, and hyaluronidases, are also present in the venom. These compounds play a crucial role in envenomation, influencing the severity of symptoms and the spread of venom. This review endeavors to comprehensively understand the T. serrulatus scorpion venom by elucidating the primary high molecular weight compounds and exploring their potential contributions to envenomation. Understanding these compounds' mechanisms of action can aid in developing more effective treatments and prevention strategies, ultimately mitigating the impact of scorpion envenomation on public health in Brazil.

Actividad antiinflamatoria in vitro de Plantago major L. y Piper aduncum L. sobre la fosfolipasa A2 del veneno de la serpiente Lachesis muta muta / In vitro anti-inflammatory activity of Plantago major L. and Piper aduncum L. on phospholipase A2 from the venom of snake Lachesis muta muta

Objetivo. Evaluar la actividad inhibitoria in vitro de los extractos de Plantago major «llantén» y Piper aduncum «matico» sobre Fosfolipasa A2 (PLA2) del veneno de la serpiente Lachesis muta muta. Materiales y métodos. Esta investigación fue de tipo explicativa con diseño experimental. Se recolectaron hojas de P. major y P. aduncum en la provincia de Huarochirí en Lima, Perú. Se prepararon extractos alcohólicos diluidos en agua destilada y se realizaron los ensayos fitoquímicos, la cuantificación de fenoles y flavonoides, la cromatografía de capa fina (CCF) en celulosa y la actividad enzimática con PLA2. Se analizó la capacidad de inhibir la PLA2 con los extractos en estudio y sus fracciones. Para el análisis estadístico se utilizó la prueba de Kruskal Wallis y comparaciones múltiples de Bonferroni. Resultados. Tanto en P. major como en P. aduncum se identificó cualitativamente la presencia de fenoles, flavonoides y taninos; además, P. aduncum presentó saponinas. La inhibición de la actividad de la PLA2 del veneno por el extracto total de P. major fue del 45,3%, y sus fracciones mostraron valores de inhibición: LLF-1 con 31,1%, LLF-2 con 66,3% y LLF-3 con 65,5%. En P. aduncum, los valores de inhibición para el extracto total fueron de 86,9%, y sus fracciones presentaron inhibiciones: MF-1 con 34,3%, MF-2 con 67,1% y MF-3 con 54,9%. El análisis estadístico demostró diferencias significativas en la inhibición de la PLA2 (p=0,009) por los extractos. Conclusión. Los ensayos realizados demostraron una asociación entre el efecto antiinflamatorio de los extractos y la inhibición de la PLA2.

Objective. To evaluate the in vitro inhibitory activity of Plantago major "llantén" and Piper aduncum "matico" extracts on phospholipase A2 (PLA2) from the venom of the snake Lachesis muta muta. Materials and methods. We carried out an explanatory study with experimental design. Leaves of P. major and P. aduncum were collected in the province of Huarochirí in Lima, Peru. Then, we prepared alcoholic extracts diluted in distilled water and conducted phytochemical assays, quantification of phenols and flavonoids, thin layer chromatography (TLC) on cellulose and enzymatic activity with PLA2. The ability to inhibit PLA2 with the extracts under study and their fractions was analyzed. The Kruskal Wallis test and Bonferroni multiple comparisons were used during statistical analysis. Results. Phenols, flavonoids and tannins were qualitatively identified in both P. major and P. aduncum; in addition, P. aduncum presented saponins. The inhibition of PLA2 activity of the venom by the total extract of P. major was 45.3%, and its fractions showed the following inhibition values: 31.1% for LLF-1, 66.3% for LLF-2 and 65.5% for LLF-3. The inhibition values for the total extract of P. aduncum were 86.9%, and its fractions showed the following inhibition rates: 34.3% for MF-1, 67.1% for MF-2 and 54.9% for MF-3. Statistical analysis showed significant differences in the inhibition of PLA2 (p=0.009) by the extracts. Conclusion. The tests demonstrated an association between the anti-inflammatory effect of the extracts and PLA2 inhibition.

Utility of serum anti-phospholipase A2 receptor antibody as a biomarker in membranous nephropathy: An experience from a tertiary care center of Eastern India

Background: Membranous nephropathy (MN) is a pattern of glomerular injury. Exact categorization into primary membranous nephropathy (PMN) or secondary membranous nephropathy (SMN) is essential for treatment. An endogenous podocyte antigen, M-type phospholipase A2 receptor (PLA2R) has been discovered to be involved in the pathogenesis of PMN. Aims and Objectives: In this article, we aimed to analyze renal tissue PLA2R and serum anti-PLA2R antibodies in MN cases and determined the diagnostic utility. Materials and Methods: The study was of prospective type carried out from March 2019 to August 2020. Analysis of cases of MN was performed with PLA2R paraffin immunoflourescence and serum anti-PLA2R antibody ELISA. Results: Overall sensitivity, specificity, PPV, and NPV of serum anti-PLA2R ELISA for PMN was 91.3%, 80%, 75%, and 93.3%, respectively, and of tissue PLA2R staining for PMN was 91.67%, 81.08%, 75.86%, and 93.75%, respectively. There was strong concordance between two methods. In the patients that were followed up, we found baseline serum anti-PLA2R antibody was less in complete remission group than that in non-remission group and the reduction in serum anti-PLA2R antibody was more in complete remission group than that in non-remission group. Conclusion: Routine light and immunofluorescence examination are incapable of giving exact categorical opinion regarding PMN and SMN. Serum anti-PLA2R antibody detection and renal tissue PLA2R analysis are sensitive and specific in detecting PMN. Baseline serum anti-PLA2R antibody and anti-PLA2R antibody quantification trends are related to prognosis of PMN. So they can be incorporated as additional biomarker.

Inhibición de enzimas fosfolipasas A2 de venenos totales de serpientes como estrategia en la búsqueda de nuevos fármacos / Enzyme phospholipase A2 inhibition from snake venoms as strategy to search for new drug

Introducción: Los fármacos antiinflamatorios no esteroideos (AINEs) son ampliamente utilizados para la terapia del dolor, a pesar de sus efectos secundarios que ocurren a nivel renal, estomacal y coagulatorio. Las fosfolipasas A2 (PLA2) presentes en los venenos de serpientes, abejas e incluso en el organismo humano, son responsables de varios procesos fisiológicos y patológicos. Las enzimas hidrolizan fosfolípidos de membrana liberando ácido araquidónico, un precursor de los eicosanoides pro-inflamatorios, los cuales originan mediadores de la inflamación. Objetivo: El propósito de este trabajo es revisar nuevas moléculas capaces de bloquear la escisión de los fosfolípidos de membrana por acción de las PLA2, evitando la formación de mediadores de inflamación. Metodología: Se realizó una revisión bibliográfica de estudios publicados desde 2011 a 2021, que reportan compuestos con actividad inhibitoria frente a PLA2. El potencial de los estudios de relación estructura actividad se discute como estrategia para encontrar compuestos activos ante PLA2. Resultados: Se revisaron 26 estudios que incluyen compuestos naturales y sintéticos y se recopilaron 93 moléculas con actividad inhibitoria, destacando su potencial como inhibidores de PLA2. Conclusiones: La actividad inhibitoria de los compuestos revisados podría estar asociada a los patrones de sustitución en el anillo bencénico de las moléculas. La evaluación de características moleculares relevantes en la inhibición de PLA2 puede guiar a la identificación de candidatos para síntesis de nuevos inhibidores enzimáticos.

Introduction: Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used for pain therapy, despite its side effects in renal, stomach and coagulant systems. Phospholipases A2 (PLA2) enzymes, present in snakes and bees' venoms, and even in the human organism, are responsible for several physiological and pathological processes. These enzymes hydrolyze membrane phospholipids, releasing arachidonic acid, a precursor of pro-inflammatory eicosanoids, which give rise to inflammatory mediators. Objective: The aim of the present work is to review new molecules able to block the cleavage of membrane phospholipids by the action of phospholipases A2, preventing the formation of inflammatory mediators. Methodology: A bibliographic revision from literature published from 2011 to 2021 focused on PLA2 inhibitors was carried out. The potential of structure-activity relationship studies is discussed as a strategy to find active compounds against PLA2. Results: 26 studies including natural and synthetic compounds were reviewed and data from 93 molecules with inhibitory activity were collected, highlighting its potential as PLA2 inhibitors. Conclusion: The inhibitory activity of the reviewed compounds could be associated with the substitution patterns in the benzene ring of the molecules. The evaluation of molecular moieties with relevant capacity to inhibit PLA2 will lead to the identification of candidates for synthesis of new enzymes inhibitors.

Polimorfismo no gene PNPLA3 e o consumo de carne vermelha aumentam o risco de fibrose em pacientes com DHGNA comprovado por biópsia em acompanhamento médico em um centro terciário no Sudoeste do Brasil / Pnpla3 gene polymorphism and red meat consumption increased fibrosis risk in nash biopsy-proven patients under medical follow-up in a tertiary center in southwest brazil

ABSTRACT Background: Recent studies show an increase in nonalcoholic fatty liver disease (NAFLD) in populations with higher consumption of red meat, processed and cooked at high temperatures. On the other hand, the single nucleotide polymorphism rs738409 in the Patatin-like phospholipase domain containing 3 (PNPLA3) gene has been implicated in susceptibility to NAFLD and liver fibrosis. However, the synergistic effect between red meat consumption and the PNPLA3 gene polymorphism in NAFLD has not yet been evaluated. Objective: To evaluate the association between the presence of the polymorphism in the PNPLA3 gene and the consumption of macronutrients, including meat consumption and its cooking method among NAFLD patients. Methods: This was a cross-sectional study with 91 patients diagnosed with NAFLD by liver biopsy with genotyping for the polymorphism in the PNPLA3 gene were included. The consumption of calories and macronutrients was verified using the semi-quantitative food frequency questionnaire and the specific questionnaire on meat consumption. PNPLA3 gene polymorphism was analyzed by real-time polymerase chain reaction (RT-PCR) and anthropometric evaluation was realized. Results: The mean BMI was 32.38±4.58 kg/m² and the waist circumference was 107±10 cm. On liver biopsy, 42% of patients had significant fibrosis (F≥2). The odds ratio of F≥2 was 2.12 for the GG group and 1.54 for the CG group, compared to the CC group. The mean caloric intake was 1170±463.20 kcal/d. The odds ratio in the CC group concerning high red meat consumption in comparison to low consumption was 1.33. For white meat, the odds ratio was 0.8 when comparing high and low intake, also in the CC group. Conclusion: High red meat intake and PNPLA3 gene polymorphism seem to synergistically affect NAFLD and liver fibrosis, requiring confirmation in a larger number of patients and in different populations.

RESUMO Contexto: Estudos recentes mostram um aumento da doença hepática gordurosa não alcoólica (DHGNA) em populações com maior consumo de carne vermelha, processada e cozida em altas temperaturas. Por outro lado, o polimorfismo rs738409 no gene Patatin-like fosfolipase contendo 3 (PNPLA3) tem sido implicado na suscetibilidade à DHGNA e fibrose hepática. No entanto, o efeito sinérgico entre o consumo de carne vermelha e o polimorfismo no gene PNPLA3 na DHGNA ainda não foi avaliado. Objetivo: Avaliar a associação entre a presença do polimorfismo no gene PNPLA3 e o consumo de macronutrientes, incluindo o consumo de carne e seu modo de cozimento em pacientes com DHGNA. Métodos: Realizamos um estudo transversal com 91 pacientes diagnosticados com DHGNA por biópsia hepática e genotipados para o polimorfismo no gene PNPLA3. O consumo de calorias e macronutrientes foi verificado por meio do questionário de frequência alimentar semi-quantitativo (QFA) e do questionário específico sobre consumo de carnes. O polimorfismo no gene PNPLA3 foi analisado por reação em cadeia da polimerase em tempo real (RT-PCR) e a avaliação antropométrica foi realizada. Resultados: O índice de massa corporal médio foi de 32,38±4,58 kg/m² e a circunferência da cintura foi de 107±10 cm. Na biópsia hepática, 42% dos pacientes apresentavam fibrose significativa (F≥2). O odds ratio de F≥2 foi de 2,12 para o grupo GG e 1,54 para o grupo GC, comparado ao grupo CC. A ingestão calórica média foi de 1.170±463,20 kcal/d. O odds ratio para alto consumo de carne vermelha no grupo CC em comparação ao baixo consumo foi de 1,33. Para a carne branca, este valor foi de 0,8 ao comparar o alto e o baixo consumo, também no grupo CC. Conclusão: A alta ingestão de carne vermelha e o polimorfismo no gene PNPLA3 parecem afetar sinergicamente a DHGNA e a fibrose hepática, necessitando de confirmação em maior número de pacientes e em diferentes populações.

Serum lipoprotein-associated phospholipase A2 level is positively correlated with the recurrence risk of acute ischemic cerebral infarction in hypertensive patients / 南方医科大学学报

OBJECTIVE@#To explore the relationship between serum lipoprotein-associated phospholipase A2 (Lp-PLA2) level and the risk of acute ischemic stroke (AIS) recurrence in hypertensive patients.@*METHODS@#This retrospective case-control study was conducted among 211 hypertensive patients with AIS treated in Foshan First People's Hospital, including 35 patients with recurrence of AIS during the 1-year follow-up as confirmed by head CT/MR. In the overall patients, 60 had grade 1 hypertension (including 5 recurrent cases), 76 had grade 2 hypertension (with 11 recurrent cases), and 75 had grade 3 hypertension (with 19 recurrent cases). Univariate analysis, multivariate logistic regression analysis, trend analysis, and smooth curve fitting analysis were performed to explore the correlation between serum Lp-PLA2 level within 24 h after admission and the risk of AIS recurrence. The predictive efficacy of serum Lp-PLA2 level for AIS recurrence in different hypertension grades was evaluated using ROC curve analysis.@*RESULTS@#Serum Lp-PLA2 level, age, NIHSS score at admission, mRS scores at 7 days, homocysteine level and smoking status differed significantly between patients with and without AIS recurrence (P < 0.05). After adjustment for confounding factors, multivariate regression analysis showed that the highest tertile of Lp-PLA2 level was associated with a 4.13-fold increase of AIS recurrence risk compared with the lowest tertile (OR=5.13, 95% CI: 1.35-19.40), and each 1 ng/mL increase of Lp-PLA2 level was associated with a 1% increase of AIS recurrence risk (OR= 1.01, 95% CI: 1.01-1.02). Serum Lp-PLA2 level was shown to positively correlate with AIS recurrence risk, and in patients with grade 3 hypertension, its areas under the ROC curve for predicting AIS recurrence was 0.869 with a specificity of 0.893 and a sensitivity of 0.737.@*CONCLUSION@#Serum Lp-PLA2 concentration is an independent risk factor and potentially an effective predictor for AIS recurrence in patients with grade 3 hypertension.

Correlation between smoking and serum lipoprotein-associated phospholipase A2 level in overweight and obese men / 中南大学学报(医学版)

OBJECTIVES@#Lipoprotein-associated phospholipase A2 (Lp-PLA2) is a vaso-specific inflammatory marker that exacerbates atherosclerotic through inflammatory responses. It can be used to predict the occurrence of adverse cardiovascular events and to assess the residual risk of cardiovascular diseases. This study aims to investigate the correlation between smoking and serum Lp-PLA2 levels in overweight and obese men, and to provide evidence for preventing the cardiovascular diseases.@*METHODS@#Male subjects, who participated in health examination at the Health Management Center, Third Xiangya Hospital, Central South University from May 1, 2020 to April 30, 2021, were selected. The smoking status and other information were collected by the Self-test Scale of Physical Examination. According to the smoking status, they were divided into a never-smoking group, a current smoking group, a quit smoking group and a passive smoking group. According to the daily smoking amount, the current smoking subjects were divided into a <10 cigarettes group, a 10 to 20 cigarettes group, a 21 to 30 cigarettes group, and a >30 cigarettes group. According to the smoking years, the current smoking subjects were divided into a <5 years group, a 5 to 10 years group, a 11 to 20 years group, and a >20 years group.Serum Lp-PLA2 levels and other clinical indexes in different smoking groups were measured and compared, the correlation between smoking and serum Lp-PLA2 levels in overweight and obese men was analyzed by logistic regression analysis.@*RESULTS@#Serum Lp-PLA2 levels were significantly different between the never-smoking group and the current smoking group (P<0.05). Logistic regression analysis showed that, before adjusting other influencing factors and in terms of smoking status, the current smoking group (OR=1.81, 95% CI 1.27 to 2.58, P<0.01) and the quit smoking group (OR=2.09, 95% CI 1.12 to 3.90, P<0.05) were positively correlated with serum Lp-PLA2 levels compared with the never-smoking group, while the passive smoking group had no correlation with serum Lp-PLA2 levels (OR=1.27, 95% CI 0.59 to 2.73, P>0.05). In terms of daily smoking amount, the 10 to 20 cigarettes group (OR=2.09, 95% CI 1.40 to 3.12, P<0.001) and the 21 to 30 cigarettes group (OR=1.98, 95% CI 1.22 to 3.20, P<0.01) were positively correlated with serum Lp-PLA2 levels compared with the never-smoking group, while the <10 cigarettes group (OR=1.45, 95% CI 0.81 to 2.60, P>0.05) and the >30 cigarettes group (OR=1.17, 95% CI 0.60 to 2.28, P>0.05) had no correlation with serum Lp-PLA2 levels. In terms of smoking years, the 5 to 10 years group (OR=1.94, 95% CI 1.07 to 3.53, P<0.05), the 11 to 20 years group (OR=2.06, 95% CI 1.33 to 3.18, P<0.01), and the >20 years group (OR=1.66, 95% CI 1.11 to 2.47, P<0.05) were positively correlated with serum Lp-PLA2 levels compared with the never-smoking group, while the <5 years group had no correlation with serum Lp-PLA2 levels (OR=1.12, 95% CI 0.38 to 3.33, P>0.05). After adjusting for age and other indicators, the correlation between smoking years and serum Lp-PLA2 levels was the same as before adjustment among the above smoking groups, except that the correlation between the smoking 5 to 10 years group and serum Lp-PLA2 levels was not significant (OR=1.77, 95% CI 0.95 to 3.29, P>0.05).@*CONCLUSIONS@#Smoking is correlated with serum Lp-PLA2 levels in overweight and obese men.

Lipoprotein-associated phospholipase A2 combined with D-dimer to fibrinogen ratio to construct a prognostic nomogram model for patients with acute myocardial infarction after percutaneous coronary intervention / 中国医师进修杂志

Objective:To construct acute ST-segment elevation myocardial infarction (STEMI) percutaneous coronary intervention (PCI) by using lipoprotein-associated phospholipase A2 (Lp-PLA2) and D-dimer to fibrinogen ratio (D/F) and other indicators postoperative patient prognosis nomogram model and evaluation of its predictive value.Methods:A total of 291 acute STEMI patients admitted to the BenQ Hospital Affiliated to Nanjing Medical University from January 2017 to January 2020 were retrospectively selected, including but not limited to Lp-PLA2 and D/F, were collected. Receiver operating characteristic (ROC) curve and multivariate Logistic regression were used to analyze the risk factors of death within 90 d after PCI in STEMI patients, and Kaplan-Meier survival curves were drawn to compare the survival of patients in different Lp-PLA2 and D/F groups. The R language software was used to build nomogram model and decision curve.Results:The AUCs of LpPLA2 and D/F for predicting the risk of death from cardiac causes at 90 s after PCI in patients with acute STEMI were 0.896 (95% CI 0.850 to 0.932) and 0.884 (95% CI 0.837 to 0.922), respectively. The values were 59.50 μg/L and 0.46 respectively ( P<0.05); the mortality rates of acute STEMI patients in LpPLA2>59.50 μg/L and D/F>0.46 groups after PCI were higher than those in LpPLA2≤59.50 μg/L group and D/F≤0.46 group ( P<0.05); age (>66 years), left ventricular ejection fraction (LVEF) (≤45%), LpPLA2 (>59.50 μg/L), D/F (>0.46), N-terminal brain natriuretic peptide precursor (>1.55 μg/L) and fasting blood glucose (>7.00 mmol/L) were the risk of death from cardiac causes at 90 d after PCI in patients with acute STEMI ( P<0.05); when the risk thresholds were >0.24, the nomogram model could provide significant additional net clinical benefit. Conclusions:Lp-PLA2 and D/F are closely related to the prognosis of patients with acute STEMI after PCI, and the nomogram model constructed in combination with other clinical indicators can effectively predict the risk of death within 90 d after PCI.

Clinical Significance of Thrombospondin Type 1 Domain-Containing 7A and Neural Epidermal Growth Factor-Like 1 Protein in M-Type Phospholipase A2 Receptor-Negative Membranous Nephropathy / 中国医学科学院学报

Objective To investigate the clinical significance of thrombospondin type 1 domain-containing 7A (THSD7A) and neural epidermal growth factor-like 1 protein (NELL1) in phospholipase A2 receptor (PLA2R)-negative membranous nephropathy (MN). Methods A total of 116 PLA2R-negative MN patients treated in Hangzhou TCM Hospital Affiliated to Zhejiang Chinese Medical University from 2014 to 2021 were enrolled in this study.Immunohistochemistry was employed to detect THSD7A and NELL1 in the renal tissue.The pathological characteristics,treatment,and prognosis were compared between positive and negative groups. Results The 116 PLA2R-negative MN patients included 23 THSD7A-positive patients and 9 NELL1-positive patients.One patient was tested positive for both proteins.The THSD7A-positive group showed higher positive rate of IgG4 (P=0.010),more obvious glomerular basement membrane (GBM) thickening (P=0.034),and higher proportion of stage Ⅱ MN and lower proportion of stage I MN (P=0.002) than the THSD7A-negative group.The NELL1-positive group had lower positive rates of C1q and IgG2 (P=0.029,P=0.001),less obvious GBM thickening (P<0.001),more extensive inflammatory cell infiltration (P=0.033),lower proportion of deposits on multi-locations (P=0.001),and lower proportion of atypical MN (P=0.010) than the NELL1-negative group.One patient with THSD7A-positive MN was diagnosed with colon cancer,while none of the NELL1-positive patients had malignancy.Survival analysis suggested that THSD7A-positive MN had worse composite remission (either complete remission or partial remission) of nephrotic syndrome than the negative group (P=0.016),whereas NELL1-positive MN exhibited better composite remission of nephrotic syndrome than the negative group (P=0.015).The MN patients only positive for NELL1 showed better composite remission of nephrotic syndrome than the MN patients only positive for THSD7A (P<0.001). Conclusions THSD7A- and NELL1-positive MN is more likely to be primary MN,and there is no significant malignancy indication.However,it might have a predictive value for the prognosis of MN.

Antileishmanial effects of γCdcPLI, a phospholipase A2 inhibitor from Crotalus durissus collilineatus snake serum, on Leishmania (Leishmania) amazonensis

BACKGROUND Leishmaniasis, a neglected disease caused by the parasite Leishmania, is treated with drugs associated with high toxicity and limited efficacy, in addition to constant reports of the emergence of resistant parasites. In this context, snake serums emerge as good candidates since they are natural sources with the potential to yield novel drugs. OBJECTIVES We aimed to show the antileishmanial effects of γCdcPLI, a phospholipase A2 inhibitor from Crotalus durissus collilineatus snake serum, against Leishmania (Leishmania) amazonensis. METHODS Promastigotes forms were exposed to γCdcPLI, and we assessed the parasite viability and cell cycle, as well as invasion and proliferation assays. FINDINGS Despite the low cytotoxicity effect on macrophages, our data indicate that γCdcPLI has a direct effect on parasites promoting an arrest in the G1 phase and reduction in the G2/M phase at the highest dose tested. Moreover, this PLA2 inhibitor reduced the parasite infectivity when promastigotes were pre-treated. Also, we demonstrated that the γCdcPLI treatment modulated the host cell environment impairing early and late steps of the parasitism. MAIN CONCLUSIONS γCdcPLI is an interesting tool for the discovery of new essential targets on the parasite, as well as an alternative compound to improve the effectiveness of the leishmaniasis treatment.

Three cases of obinutuzumab treatment for rituximab-resistant phospholipase A 2 receptor- associated membranous nephropathy / 中华肾脏病杂志

Rituximab is currently used as a first-line therapy for phospholipase A 2 receptor-associated membranous nephropathy due to its good efficacy and safety. Although the remission rate after rituximab treatment is more than 60%, nearly 40% patients still do not respond to treatment. We used obinutuzumab to treat 3 cases of rituximab resistant PLA 2R-associated membranous nephropathy. After the first dose of 1 000 mg with or without additional dose, the amount of anti-PLA 2R antibody and urinary protein decreased significantly and the adverse reactions were mild. The results show that obinutuzumab has a certain therapeutic effect on rituximab resistant PLA 2R-associated membranous nephropathy, but the time of follow-up observation is short and can only be used as individual cases, which needs to be confirmed by a large sample and high-quality prospective cohort study.

Analysis of treatment responses and kidney prognosis of atypical membranous nephropathy / 中华肾脏病杂志

Objective:To analyze the clinicopathological characteristics, treatment responses and kidney outcomes of patients with atypical membranous nephropathy (MN), and to provide information for the clinical practice.Methods:The clinical data of patients with atypical MN and synchronous primary MN who were diagnosed, treated and followed up in Peking University First Hospital from January 2008 to June 2020 were retrospectively collected and analyzed. Clinicopathological features, treatment responses and kidney prognosis were compared between the two groups. The expression of phospholipase A2 receptor (PLA2R) in kidney tissues was detected by immunofluorescence. Serum anti-PLA2R antibody was detected by enzyme-linked immunosorbent assay. Clinicopathological indexes were compared between PLA2R-related MN group and non-PLA2R-related MN group. Kaplan-Meier (Log-rank test) survival curve and multivariate Cox regression analysis methods were used to analyze the influencing factors of kidney prognosis in patients with atypical MN. The primary endpoint of renal adverse outcome was renal insufficiency, defined as end-stage renal disease or estimated glomerular filtration rate (eGFR) decline>30% baseline and<60 ml·min -1·(1.73 m 2) -1. Results:A total of 65 atypical MN patients were enrolled in this study. Compared with primary MN ( n=324), patients with atypical MN had younger age ( Z=-4.229, P<0.001), higher proportion of hematuria ( χ2=5.555, P=0.018), higher level of urinary protein ( Z=2.228, P=0.026) and lower level of eGFR ( t=-5.108, P<0.001); the proportion of IgG4 deposition in kidneys was lower ( χ2=8.081, P=0.004), and the proportions of IgA ( χ2=16.969, P<0.001) and IgM ( χ2=9.281, P=0.002) deposition were higher. There was no significant difference on gender, serum albumin, positive proportion of anti-PLA2R antibody, anti-PLA2R antibody level and kidney C3/C1q deposition between the two groups (all P>0.05). The proportions of atypical MN patients receiving renin-angiotensin aldosterone system inhibitors (49.3% vs 57.1%), calcineurin inhibitors (27.7% vs 19.1%) and cyclophosphamide (21.5% vs 23.8%) were comparable to those of primary MN patients (all P>0.05). The rates of clinical remission (80.0% vs 77.2%), partial remission (44.6% vs 44.1%), complete remission (35.4% vs 33.1%), spontaneous remission (36.9% vs 42.6%), response to cyclophosphamide (85.7% vs 81.8%), response to calcineurin inhibitor (88.9% vs 79.0%), and relapse (30.8% vs 26.8%) in atypical MN patients were comparable to those in primary MN patients (all P>0.05). During the follow-up 30.0(21.5, 61.5) months, 15 atypical MN patients (23.1%) had eGFR reduction>30%, among whom 7 patients (10.8%) had eGFR reduction>50% and 3 patients (4.6%) had end-stage kidney disease. There was no significant difference on poor kidney prognosis between the two groups (all P>0.05). Kaplan-Meier survival curve showed that patients with age>39 years old ( χ2=10.092, P=0.001), eGFR≤100 ml·min -1·(1.73 m 2) -1( χ2=5.491, P=0.019), tubular interstitial lesion ( χ2=6.999, P=0.008) and no nephropathy remission ( χ2=22.952, P<0.001) had earlier poor renal prognosis. Multivariate Cox regression analysis showed that no nephropathy remission ( HR=12.604, 95% CI 2.691-59.037, P=0.001) was an independent influencing factor for poor renal prognosis in atypical MN patients. Conclusion:No significant difference is found between atypical MN and primary MN on treatment responses and kidney prognosis, which implies that clinical practice of atypical MN can be performed by referring to the guidelines and experience of primary MN.

The 493th case: recurrent edema of bilateral lower extremeties / 中华内科杂志

A 43-year-old male patient with onset of edema caused by nephrotic proteinuria and low titer of anti-M type phospholipase-A 2-receptor (PLA 2R) antibody was diagnosed as idiopathic membranous nephropathy by renal biopsy. Administrated with prednisone 40 mg once a day and cyclosporine 100 mg twice a day as front-line regimen, the patient relapsed after transient partial remission. When treatment was combined with cyclophosphamide 100 mg once a day, the 24-hour total urine protein and titer of anti-PLA 2R antibody were even elevated. Therefore, the patient received rituximab 1 g intravenously in April 2019, October 2019 and October 2020 respectively. CD19 positive B lymphocytes in peripheral blood were eliminated from 71/μl to zero. Immunosuppressants and corticosteroids were withdrawn successively. On the last follow-up in November 2020, the anti-PLA 2R antibody was negative, and the 24-hour total urine protein and serum albumin was 4.4 g and 34 g/L, respectively. This case suggested the potential efficacy of rituximab for refractory membranous nephropathy. Further studies should explore whether the titer of anti-PLA 2R antibody indicates the dose of rituximab.

The correlation of serum lipoprotein-associated phospholipase A2 with intra-stent restenosis after drug-eluting stent implantation / 中国医师杂志

Objectives:To investigate the correlation of serum lipoprotein-associated phospholipase A2 (Lp-PLA2) with intra-stent restenosis (ISR) after drug-eluting stent (DES) implantation.Methods:A total of 227 patients with coronary artery disease, who were diagnosed with severe epicardial coronary stenosis by coronary angiography (CAG) and treated by percutaneous coronary intervention (PCI) and DES implantation were enrolled in our study. After follow-up for 1-1.5 years, the CAG was performed and the patients were divided into ISR group and non-ISR (nISR) group according to the consequence of CAG. Biochemical data and multiple serum inflammatory factors such as Lp-PLA2, hypersensitive C-reactive protein (hs-CRP), interleukin 2 (IL-2), interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α) were analyzed before the CAG. Multivariate logistic regression and multiple linear regression were used to analyze the influencing factors of stent restenosis after DES implantation.Results:The level of serum Lp-PLA2 and the proportion of hypertension in ISR group were significantly higher than those in nISR group, and the level of high density lipoprotein cholesterol (HDL-C) was significantly lower than that in nISR group (all P<0.05), but there was no significant difference in other biochemical indexes and inflammatory factors between the two groups (all P>0.05). The minimum lumen diameter of stent segment in ISR group was significantly lower than that in nISR group ( t=14.975, P<0.01), and the stenosis degree of stent segment diameter was significantly higher than that in nISR group ( P<0.01). Multivariate logistic regression analysis showed that Lp-PLA2 remained an independent predictor for ISR (1.011, 95% CI: 1.005-1.017). Only the serum levels of Lp-PLA2 had linear relationship with the degree of ISR by multivariate linear regression analysis ( β=0.790, P<0.01). Conclusions:Serum Lp-PLA2 level is independently associated with an increased risk of ISR in patients with coronary heart disease.

The correlation between the level of PLA 2R and the condition and prognosis of patients with primary membranous nephropathy / 中国医师杂志

Objective:To investigate the correlation between serum anti phospholipase A2 receptor (PLA 2R) antibody level and the condition and prognosis of patients with primary membranous nephropathy (PMN).Methods:61 patients who were diagnosed as PMN in the laboratory department of Jiangsu Province Hospital of Chinese Medicine from January 2017 to August 2019 were selected and divided into PLA 2R positive group (41 cases) and PLA 2R negative group (20 cases) according to the level of PLA 2R antibody. The gender, age and other general data of the two groups were collected, and the clinical pathological characteristics and prognosis of the two groups were analyzed. Spearman correlation was used to analyze the correlation between the level of PLA 2R antibody and the disease condition and treatment prognosis.Results:The levels of estimate glomerular filtration rate (eGFR), total protein (TP) and albumin (ALB) in PLA 2R positive group were lower than those in PLA 2R negative group, while the levels of 24-h urinary protein and IgG4 were higher in PLA 2R positive group than that in PLA 2R negative group ( P<0.05); Multivariate logistic regression analysis showed that 24-hour urinary protein was an independent risk factor for PLA 2R antibody level ( OR=2.242, P<0.05), while TP and ALB levels were protective factors ( OR=0.840, 0.674, P<0.05); The patients in both groups were followed up for one year by rechecking serological indexes. The complete remission rate and total remission rate of PLA 2R positive group were lower than those of PLA 2R negative group ( P<0.05); Spearman correlation analysis showed that the level of PLA 2R antibody was negatively correlated with the levels of TP, ALB, and prognosis of patients ( r=-0.642, -0.547, -0.357, P<0.05), and positively correlated with the level of 24-hour urinary protein ( r=0.347, P<0.05). PLA 2R in renal tissue of 61 patients was found to be positive in 63.93% (39/61). Conclusions:The level of PLA 2R antibody is closely related to serum albumin, TP, 24 h urinary protein and prognosis of patients with PMN.

Clinical features and prognostic analysis of primary membranous nephropathy in children with positive glomerular M-type phospholipase A2 receptor / 中华实用儿科临床杂志

Objective:To analyze the clinical and prognosis of primary membranous nephropathy (PMN) in children with positive glomerular M-type phospholipase A2 receptor (PLA2R).Methods:A total of 69 children diagnosed with PMN by renal biopsy admitted to the Department of Pediatrics of Eastern Theater Command General Hospital from January 2006 to December 2018 were retrospectively analyzed, including 40 males and 29 females, with an average age of 14.86 years.According to the immunofluorescence of renal pathology, they were divided into PLA2R positive group and PLA2R negative group.Pathological features between 2 groups were compared by the t test, Mann- Whitney U test and Chi- square test.Kaplan-Meier method was used to compare the long-term renal survival rate and cumulative remission rate between 2 groups. Results:A total of 69 pediatric PMN patients were included.The po-sitive rates of serum anti-PLA2R antibody and positive expression of PLA2R in renal tissues were 53.6% (37 cases) and 82.6% (57 cases), respectively.The proportion of children with clinical manifestations of large proteinuria [55 cases(96.5% ) vs.9 cases(75.0%), P=0.034] was significantly higher in the PLA2R positive group than that of the PLA2R negative group.Blood urea nitrogen level was significantly higher in the PLA2R positive group than that of PLA2R negative group[1.14(0.93, 1.54) mg/L vs.0.80 (0.44, 1.18) mg/L, P=0.049], while estimate glomerular filtration rate(eGFR) [162.26 (139.81, 185.53) mL/(min·1.73 m 2) vs.199.52 (157.58, 212.01) mL/(min·1.73 m 2), P=0.034] and serum IgG [3.58 (2.50, 5.43) g/L vs.5.14 (4.35, 6.03) g/L, P=0.016] were significantly lower.The cumulative remission rate was significantly higher in the PLA2R negative group than that of PLA2R positive group ( P<0.001). The 24 h urinary protein ≥50 mg/kg ( HR=0.119, 95% CI: 0.021-0.595, P=0.010)was an independent risk factor for renal prognosis, and PLA2R( HR=0.263, 95% CI: 0.125-0.551, P<0.001) and 24 h urinary protein ≥50 mg/kg ( HR=0.568, 95% CI: 0.125-0.551, P=0.041)were independent predictors of urinary protein remission.PLA2R ( HR=1.020, 95% CI: 0.698-1.682, P=0.656)was not associated with renal prognosis. Conclusions:The severity of PMN in children with positive PLA2R was higher than that in those with negative PLA2R.The long-term cumulative remission rate of PLA2R negative children with PMN was higher than that of PLA2R positive children.

Phospholipid remodeling and Parkinson's disease / 药学学报

The remodeling of phospholipid includes two processes: deacylation and reacylation. It realizes the conversion of nascent phospholipids to mature phospholipids by changing the length and types of fatty acids at specific sites of phospholipids, which is a key step in phospholipid metabolism. Phospholipids are not only the basic components of biological membranes, but also participate in the transduction of many molecular signals in cells. Therefore, phospholipid remodeling disorders can affect the structure and function of cell membranes, as well as the activity of membrane proteins, causing a series of intricate signaling cascades, and finally lead to many pathological changes including neurodegeneration. This paper reviews the basic process of phospholipid remodeling and the involvement of its key enzymes, calcium independent group VIA phospholipase A2 (iPLA2β), peroxiredoxin 6 (PRDX6), calcium independent group VIB phospholipase A2 (iPLA2γ) as well as acyl-CoA lysocardiolipin acyltransferase 1 (ALCAT1) in the pathology of Parkinson's disease. The mutations in the gene encoding iPLA2β, PLA2G6, have been widely reported to be directly related to hereditary Parkinson disease-14 (PARK14). Here we focus on the molecular mechanism of iPLA2β in the development of Parkinson's disease, mainly involving phospholipid fatty acid metabolism disorders, mitochondrial physiology abnormalities and α-synuclein aggregate formation and other aspects, which will help to understand the role of phospholipid remodeling in Parkinson's disease, and provide new clues for the development of new Parkinson's disease diagnosis and treatment strategies.

Clinicopathological characteristics of idiopathic membranous nephropathy in elderly patients / 中华老年医学杂志

Objective:To compare the clinicopathological differences between elderly and non-elderly patients with idiopathic membranous nephropathy(IMN).Methods:Patients diagnosed with IMN via renal biopsy at Beijing Huairou Hospital, Beijing Changping Hospital of Traditional Chinese Medicine, and Beijing Hospital of Traditional Chinese Medicine from January 2017 to August 2021 were retrospectively enrolled.They were classified into the elderly group(≥65 years)and the non-elderly group(<65 years), and the clinicopathological differences between the two groups were compared.Results:A total of 207 IMN patients were included in the study, with a male to female ratio of 1.7∶1.0.There were 56 patients in the elderly group, aged(68.2±3.1)years, and 151 patients in the non-elderly group, aged(48.2±6.2)years.Compared with the non-elderly group, the elderly group had a longer time from onset to renal biopsy and a higher proportion of patients with renal insufficiency and hypertension( P<0.05). The elderly group had a lower eGFR, lower serum albumin, higher serum cholesterol, and higher low-density lipoprotein than the non-elderly group( P<0.05). The proportions of patients with glomerulosclerosis, renal tubular atrophy, and interstitial fibrosis in the elderly group were higher than in the non-elderly group( P<0.05). The positive rates of glomerular PLA2R antigen staining in the two groups were 90.6%(29/32)and 91.0%(111/122), respectively, and there was no statistically significant difference between the two groups.IgG4 deposition represented the most common IgG subtype, with 93.8%(30/32)in the elderly group and 94.3%(115/122)in the non-elderly group.There was no statistical significance between the two groups( P>0.05). Conclusions:Compared with non-elderly IMN patients, a higher proportion of elderly IMN patients has renal insufficiency, hypertension and chronic renal pathology.The glomerular deposition of pathogenic antigens in elderly IMN patients was similar to that in non-elderly IMN patients, suggesting no difference in pathogenesis between the two groups.The clinicopathological differences between the two groups may be related to age and complications.