Targeted lipidomics reveals phospholipids and lysophospholipids as biomarkers for evaluating community-acquired pneumonia

Abstract

Background: Community-acquired pneumonia (CAP) is often accompanied by changes in lipid metabolism. This study aimed to examine the changes in serum phospholipids (PLs) that may be useful for early disease stratification and as potential therapeutic targets in patients with CAP.Methods: Serum samples from 58 patients hospitalized with CAP and 11 control samples were collected during admission between January 2017 and October 2018. Targeted lipidomic analysis was used to determine the concentrations of phosphatidylcholine (PC), lysophosphatidylcholine (LPC), phosphatidylethanolamine (PE), and lysophosphatidylethanolamine (LPE). The Gene Expression Omnibus (GEO) database was used to evaluate the gene expression levels of key enzymes in the Lands cycle, and quantitative real-time polymerase chain reaction (qRT-PCR) was used for further verification.Results: A significant decrease in LPC levels and an increase in PE levels, PC/LPC and PE/LPE ratios were observed in patients with CAP (P<0.05). The area under the curve (AUC) of PE serum concentrations combined with CURB-65 scores (confusion, uremia, respiratory rate, blood pressure, and age ≥65 years) was 0.848 for discriminating disease severity, which was significantly higher than the discriminating disease severity of CURB-65 (P<0.05). The efficiency of predicting 30-day mortality using PC, LPC, or PC/LPC ratio combined with CURB-65 scores (AUC =0.811, AUC =0.854, AUC =0.838, respectively) was better than CURB-65 alone (P<0.05). Gene expression analysis revealed the upregulation of LPC acyltransferase 2.Conclusions: LPC or PE serum levels as well as PC/LPC ratios combined with CURB-65 are effective biomarkers for predicting the disease severity and 30-day mortality of patients with CAP. Further investigations of phospholipid metabolism will improve our understanding and treatment of CAP.

Lysophosphatidylcholine Acetyltransferase 2 (LPCAT2) Influences the Gene Expression of the Lipopolysaccharide Receptor Complex in Infected RAW264.7 Macrophages, Depending on the E. coli Lipopolysaccharide Serotype

“…Moreover, LPCAT2 has been implicated as a biomarker for inflammatory disorders such as cedar pollen allergenic rhinitis [31], pneumonia [32], and pulmonary tuberculosis [33]. All these publications support evidence that LPCAT2 is pro-inflammatory; however, data on the effect of LPCAT2 on various pro-inflammatory molecules are unavailable.…”

Predictive Value of Lysophosphatidylcholine for Determining the Disease Severity and Prognosis of Elderly Patients with Community-Acquired Pneumonia

“… 39 Based on numerous studies, serum LPC levels show significant association with disease severity and show great promise for clinical application as a prognostic prediction biomarker. Ma et al 21 reported that the serum LPC levels were significantly lower in patients with SCAP than in patients with non-SCAP. Furthermore, the AUC value for LPC was 0.708 ( P = 0.0044) for predicting SCAP and 0.789 for predicting 30-day death in CAP patients ( P < 0.0001).…”

“…Metabolomics and lipidomics data demonstrated that low serum LPC levels were associated with increased disease severity in patients with COVID-19. 21,22 However, Barberis et al and Song et al reported that serum LPC levels were elevated in patients with COVID-19. 23,24 The reasons for these contradictory findings are not clear.…”

Plasma metabolomic signatures from patients following high-dose total body irradiation

“…10,42,43 PC and PE are the most mammalian phospholipids, which act as the main structural components of cellular membranes and play important roles in lipid regulation, lipoproteins and energy metabolism. 44 LPC and LPE are both generated from membrane phospholipid hydrolysis by phospholipase A2 (PLA2). PC can be synthesised in the body via two different routes: the CDP-choline pathway, which is found in all nucleated cells, as well as in the phosphatidylethanolamine N-methyltransferase (PEMT) pathway, which is primarily found in the liver.…”