Untargeted metabolomics analysis of the plasma metabolic signature of moderate-to-severe acne

Repurposing lipid-lowering drugs as potential treatment for acne vulgaris: a Mendelian randomization study

Background

Acne vulgaris, a chronic inflammatory skin condition predominantly seen in teenagers, impacts more than 640 million people worldwide. The potential use of lipid-lowering medications as a treatment for acne vulgaris remains underexplored. This study seeks to investigate the impact of lipid-lowering therapies on the risk of developing acne vulgaris using two-sample Mendelian randomization (MR) analysis.

Method

The two-sample MR method was employed for analysis, and information on lipid-lowering drugs was obtained from the DrugBank and ChEMBL databases. The summary data for blood low-density lipoprotein (LDL) and triglycerides were sourced from the Global Lipids Genetics Consortium, while genome-wide association studies (GWAS) summary data for acne vulgaris were obtained from the FinnGen database. Heterogeneity was examined using the Q-test, horizontal pleiotropy was assessed using MR-Presso, and the robustness of analysis results was evaluated using leave-one-out analysis.

Results

The MR analysis provided robust evidence for an association between lowering LDL cholesterol through two drug targets and acne vulgaris, with PCSK9 showing an odds ratio (OR) of 1.782 (95%CI: 1.129-2.812, p = 0.013) and LDL receptor (LDLR) with an OR of 1.581 (95%CI: 1.071-2.334, p = 0.021). Similarly, targeting the lowering of triglycerides through lipoprotein lipase (LPL) was significantly associated with an increased risk of acne vulgaris, indicated by an OR of 1.607 (95%CI: 1.124-2.299, p = 0.009).

Conclusion

The current MR study presented suggestive evidence of a positive association between drugs targeting three genes (PCSK9, LDLR, and LPL) to lower lipids and a reduced risk of acne vulgaris.

UHPLC-qTOF-MS-Based Nontargeted Metabolomics to Characterize the Effects of Capsaicin on Plasma and Skin Metabolic Profiles of C57BL/6 Mice-An In vivo Experimental Study

Background

Capsaicin is the main compound found in chili pepper and has complex pharmacologic effects. This study aimed to elucidate the mechanism of the effect of capsaicin on physiological processes by analyzing changes in metabolites and metabolic pathways.

Methods

Female C57BL/6 mice were divided into two groups(n = 10/group) and fed with capsaicin-soybean oil solution(group T) or soybean oil(group C) for 6 weeks. Ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC-qTOF-MS) based metabolomics was undertaken to assess plasma and skin metabolic profile changes and identify differential metabolites through multivariate analysis.

Results

According to the OPLS-DA score plots, the plasma and skin metabolic profiles in the group T and group C were significantly separated. In plasma, 38 significant differential metabolites were identified. KEGG pathway enrichment analysis revealed that the most significant plasma metabolic pathways included pyruvate metabolism and ABC transporters. In skin, seven significant differential metabolites were found. Four metabolic pathways with p values < 0.05 were detected, including sphingolipid metabolism, sphingolipid signaling pathway, apoptosis, and necroptosis.

Conclusion

These findings will provide metabolomic insights to assess the physiological functions of capsaicin and contribute to a better understanding of the potential effects of a capsaicin-rich diet on health.

Targeted metabolomics reveals the association between central carbon metabolism and pulmonary nodules

With the widespread application of low-dose computed tomography (LDCT) technology, pulmonary nodules have aroused more attention. Significant alteration in plasma metabolite levels, mainly amino acid and lipid, have been observed in patients of PNs. However, evidence on the association between central carbon metabolism and PNs are largely unknown. The aim of this study was to investigate the underlying association of PNs and plasma central carbon metabolites. We measured the levels of 16 plasma central carbon metabolites in 1954 participants who gained LDCT screening in MALSC cohort. The inverse probability weighting (IPW) technique was used to control for bias due to self-selection for LDCT in the assessed high-risk population. The least absolute shrinkage and selection operator (LASSO) penalized regression was used to deal with the problem of multicollinearity among metabolites and the combined association of central carbon metabolites with PNs was estimated by using quantile g-computation (QgC) models. A quartile increase in 3-hydroxybutyric acid, gluconic acid, succinic acid and hippuric acid was positively associated with the PNs risk, whereas a quartile increase in 2-oxadipic acid and fumaric acid was negatively associated with the risk of PNs in multiple-metabolite models. A positive but insignificant joint associations of the mixture of 16 metabolites with PNs was observed by using QgC models analyses. Further studies are warranted to clarify the association between circulating metabolites and PNs and the biological mechanisms.

Untargeted metabolomics analysis of plasma metabolic characteristics in patients with acne and insulin resistance

Acne vulgaris is a chronic inflammatory disease with high incidence, diverse clinical manifestations, poor clinical efficacy, and easy recurrence. Recent studies have found that the occurrence of acne is related to metabolic factors such as insulin resistance; however, the specific mechanism of action remains unclear. This study aimed to identify significantly different metabolites and related metabolic pathways in the serum of acne vulgaris patients with or without insulin resistance. LC-MS/MS was used to analyze serum samples from patients about acne with insulin resistance (n = 51) and acne without insulin resistance (n = 69) to identify significant metabolites and metabolic pathways. In this study, 18 significant differential metabolites were screened for the first time. In the positive-ion mode, the upregulated substances were creatine, sarcosine, D-proline, uracil, Phe-Phe, L-pipecolic acid, and DL-phenylalanine; the downregulated substances were tridecanoic acid (tridecylic acid), L-lysine, cyclohexylamine, sphingomyelin (d18:1/18:0), gamma-L-Glu-epsilon-L-Lys, and 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine. In the negative-ion mode, the upregulated substance was cholesterol sulfate, and the downregulated substances were D(-)-beta-hydroxybutyric acid, myristic acid, D-galacturonic acid, and dihydrothymine. Cholesterol sulfate showed the most significant expression among all differential metabolites (VIP = 7.3411). Based on the KEGG database, necroptosis and ABC transporters were the most significantly enriched metabolic pathways in this experiment. The differential metabolites and pathways identified in this study may provide new possibilities for the clinical diagnosis and development of targeted drugs for acne patients with insulin resistance.

Untargeted Plasma Lipidomics Reveal Perturbed Metabolites of Glycerophospholipids, and Sphingolipids in Moderate-to-Severe Acne

Background

Acne vulgaris (AV) is a common inflammatory disorder involving the pilosebaceous unit. The study aimed to explore the plasma lipidome signatures and identify specific lipid biomarkers in moderate-to-severe acne patients.

Patients and Methods

Untargeted plasma lipidomic analysis using ultra-high performance liquid chromatography system (UHPLC) coupled to q-extraction plus was employed on 30 moderate-to-severe acne patients aged between 16-25 years and 30 healthy controls. Multivariate data analyses were used to identify the distinguishing lipid metabolites.

Results

All 1449 species of 37 lipid subclasses were identified from the MS data. There were apparent differences in plasma lipid profiles between acne groups and control groups. With variable influence on projection (VIP) > 1.0 and P-value < 0.05, 26 significantly different lipid metabolites were identified. These metabolites consisted mainly of glycerophospholipids (GPs), sphingolipids (SPs), and glycerolipids (GLs). Combining with AUC≥0.800 as the elected criteria, we obtained five differential lipids with good diagnostic performance for acne severity, including 2 sphingomyelins (SM), 1 phosphatidylglycerol (PG), 1 trihexosylceramide (Hex3Cer), and 1 Phosphatidylcholine (PC). Among them, PG (44:0) had the highest AUC values.

Conclusion

Our study revealed the plasma lipidome signature of patients with moderate-to-severe acne. The results will provide a novel light into the perturbed lipid metabolism leading to the development of acne.

Lipid Alterations and Metabolism Disturbances in Selected Inflammatory Skin Diseases

Lipidomics is a term used to define the field that analyzes the structure, functions, and interactions of lipids. Inflammatory dermatoses and lipid disturbances are interrelated, especially due to chronic inflammatory conditions. This review discusses lipidomics in selected inflammatory skin diseases: psoriasis, lichen planus, and atopic dermatitis, as well as the less commonly mentioned hidradenitis suppurativa, rosacea, and acne vulgaris. Lipid homeostasis disorders are common; they are especially well-documented in psoriasis, lichen planus, and atopic dermatitis. Future studies are required for better insight into this issue, particularly on the skin lipidome. Understanding lipidomics, in particular skin diseases, increases our knowledge about their pathogenesis, and may become useful in adjusting tailored management for each patient as well establishing prognosis. Noteworthily, it seems advisable to alert doctors to the need to analyze lipid parameters and the complications of abnormal lipid metabolism in dermatological patients, which could decrease their comorbidities and improve the life quality and health condition of dermatological patients.

Nontargeted metabolomics to characterize the effects of isotretinoin on skin metabolism in rabbit with acne

Background: Acne vulgaris is a chronic inflammatory disease of the pilosebaceous unit. This study aimed to explore the pathogenesis of acne and the therapeutic mechanism of isotretinoin from the metabolic perspective in coal tar-induced acne in rabbits.

Methods: Ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC-qTOF-MS) based metabolomics was used to identify skin metabolites in groups C (blank control), M (model group) and T (isotretinoin group). Multivariate statistical analysis was used to process the metabolomics data.

Results: 98 differential metabolites in group C and group M were identified. The highest proportion of differential metabolites were organic acids and derivatives, lipid metabolites, organic heterocyclic compounds, and nucleoside metabolites. The most significant metabolic pathways included protein digestion and absorption, central carbon metabolism in cancer, ABC transporters, aminoacyl-tRNA biosynthesis, biosynthesis of amino acids, and sphingolipid signaling pathway. Isotretinoin treatment normalized eight of these metabolites.

Conclusions: Our study will help to further elucidate the pathogenesis of acne, the mechanism of isotretinoin at the metabolite level, and identify new therapeutic targets for treating acne.