Targeted lipidomics analysis identified altered serum lipid profiles in patients with polymyositis and dermatomyositis

Effect of atorvastatin on muscle tissues of dermatomyositis and antisynthetase syndrome patients with dyslipidemia

INTRODUCTION

In a recent study, we have shown that atorvastatin is clinically safe for dermatomyositis (DM) and antisynthetase syndrome (ASS) patients with dyslipidemia. Herein, we showed in an unprecedented way, the safety of atorvastatin on the muscular tissues of these patients.

METHODS

Transcriptome analysis was performed on samples of the vastus lateralis muscle obtained at baseline and after 12 weeks of atorvastatin (20 mg/day) intervention in DM or ASS patients with dyslipidemia [6DM and 5ASS received atorvastatin, and 2DM and 3ASS received placebo]. The results were analyzed considering differences in expression fold change before and after treatment. Histological and histochemical analyses were also performed.

RESULTS

In both groups, no significant changes were observed in genes related to the mitochondrial, oxidative, insulin, lipid, and fibrogenic pathways. Histological analysis showed a slight variability in the fiber size that was preserved after the intervention. In addition, the mosaic of muscle fibers was preserved in the internal architecture of the fibers and all histological regions. No fiber necrosis or atrophy, focal failures, subsarcolemmal accumulation, lipids, areas of fibrosis, or alterations in mitochondrial activity were observed. All muscle fibers were labeled for MHC I.

CONCLUSION

Atorvastatin did not promote significant changes in the expression of genes related to mitochondrial, oxidative, insulin, lipid, and fibrogenic pathways in the muscle tissues of DM and ASS patients with dyslipidemia. Atorvastatin did not also promote histological and histochemical changes in muscle tissues. Our results reinforce the safety of the administration of atorvastatin to treat dyslipidemia in patients with DM and ASS.

Metabolic profiling of patients with different idiopathic inflammatory myopathy subtypes reveals potential biomarkers in plasma

Idiopathic inflammatory myopathy (IIM) are heterogeneous autoimmune diseases that primarily affect the proximal muscles. IIM subtypes include dermatomyositis (DM), polymyositis (PM), and anti-synthetase syndrome (ASS). Metabolic disturbances may cause irreversible structural damage to muscle fibers in patients with IIM. However, the metabolite profile of patients with different IIM subtypes remains elusive. To investigate metabolic alterations and identify patients with different IIM subtypes, we comprehensively profiled plasma metabolomics of 46 DM, 13 PM, 12 ASS patients, and 30 healthy controls (HCs) using UHPLC-Q Exactive HF mass spectrometer. Multiple statistical analyses and random forest were used to discover differential metabolites and potential biomarkers. We found that tryptophan metabolism, phenylalanine and tyrosine metabolism, fatty acid biosynthesis, beta-oxidation of very long chain fatty acids, alpha-linolenic acid and linoleic acid metabolism, steroidogenesis, bile acid biosynthesis, purine metabolism, and caffeine metabolism are all enriched in the DM, PM, and ASS groups. We also found that different subtypes of IIM have their unique metabolic pathways. We constructed three models (five metabolites) to identify DM, PM, ASS from HC in the discovery and validation sets. Five to seven metabolites can distinguish DM from PM, DM from ASS, and PM from ASS. A panel of seven metabolites can identify anti-melanoma differentiation-associated gene 5 positive (MDA5 +) DM with high accuracy in the discovery and validation sets. Our results provide potential biomarkers for diagnosing different subtypes of IIM and a better understanding of the underlying mechanisms of IIM.

The Metabolic Footprint of Systemic Effects in the Blood Caused by Radiotherapy and Inflammatory Conditions: A Systematic Review

Response to radiotherapy (RT) includes tissue toxicity, which may involve inflammatory reactions. We aimed to compare changes in metabolic patterns induced at the systemic level by radiation and inflammation itself. Patients treated with RT due to head and neck cancer and patients with inflammation-related diseases located in the corresponding anatomical regions were selected. PubMed and Web of Science databases were searched from 1 January 2000 to 10 August 2023. Twenty-five relevant studies where serum/plasma metabolic profiles were analyzed using different metabolomics approaches were identified. The studies showed different metabolic patterns of acute and chronic inflammatory diseases, yet changes in metabolites linked to the urea cycle and metabolism of arginine and proline were common features of both conditions. Although the reviewed reports showed only a few specific metabolites common for early RT response and inflammatory diseases, partly due to differences in metabolomics approaches, several common metabolic pathways linked to metabolites affected by radiation and inflammation were revealed. They included pathways involved in energy metabolism (e.g., metabolism of ketone bodies, mitochondrial electron transport chain, Warburg effect, citric acid cycle, urea cycle) and metabolism of certain amino acids (Arg, Pro, Gly, Ser, Met, Ala, Glu) and lipids (glycerolipids, branched-chain fatty acids). However, metabolites common for RT and inflammation-related diseases could show opposite patterns of changes. This could be exemplified by the lysophosphatidylcholine to phosphatidylcholine ratio (LPC/PC) that increased during chronic inflammation and decreased during the early phase of response to RT. One should be aware of dynamic metabolic changes during different phases of response to radiation, which involve increased levels of LPC in later phases. Hence, metabolomics studies that would address molecular features of both types of biological responses using comparable analytical and clinical approaches are needed to unravel the complexities of these phenomena, ultimately contributing to a deeper understanding of their impact on biological systems.

Identification of Metabolic Signature Associated with Idiopathic Inflammatory Myopathy Reveals Polyamine Pathway Alteration in Muscle Tissue

Idiopathic inflammatory myopathy (IIM) is hard to diagnose without a muscle biopsy. We aimed to identify a metabolite panel for IIM detection by metabolomics approach in serum samples and to explore the metabolomic signature in tissue samples from a mouse model. We obtained serum samples from IIM patients, ankylosing spondylitis (AS) patients, healthy volunteers and muscle tissue samples from IIM murine model. All samples were subjected to a targeted metabolomic approach with various statistical analyses on serum and tissue samples to identify metabolic alterations. Three machine learning methods, such as logistic regression (LR), support vector machine (SVM), and random forest (RF), were applied to build prediction models. A set of 7 predictive metabolites was calculated using backward stepwise selection, and the model was evaluated within 5-fold cross-validation by using three machine algorithms. The model produced an area under the receiver operating characteristic curve values of 0.955 (LR), 0.908 (RF) and 0.918 (SVM). A total of 68 metabolites were significantly changed in mouse tissue. Notably, the most influential pathways contributing to the inflammation of muscle were the polyamine pathway and the beta-alanine pathway. Our metabolomic approach offers the potential biomarkers of IIM and reveals pathologically relevant metabolic pathways that are associated with IIM.

Integrated analysis of plasma and urine reveals unique metabolomic profiles in idiopathic inflammatory myopathies subtypes

OBJECTIVES

Idiopathic inflammatory myopathies (IIM) are a class of autoimmune diseases with high heterogeneity that can be divided into different subtypes based on clinical manifestations and myositis-specific autoantibodies (MSAs). However, even in each IIM subtype, the clinical symptoms and prognoses of patients are very different. Thus, the identification of more potential biomarkers associated with IIM classification, clinical symptoms, and prognosis is urgently needed.

METHODS

Plasma and urine samples from 79 newly diagnosed IIM patients (mean disease duration 4 months) and 52 normal control (NC) samples were analysed by high-performance liquid chromatography of quadrupole time-of-flight mass spectrometry (HPLC-Q-TOF-MS)/MS-based untargeted metabolomics. Orthogonal partial least-squares discriminate analysis (OPLS-DA) were performed to measure the significance of metabolites. Pathway enrichment analysis was conducted based on the KEGG human metabolic pathways. Ten machine learning (ML) algorithms [linear support vector machine (SVM), radial basis function SVM, random forest, nearest neighbour, Gaussian processes, decision trees, neural networks, adaptive boosting (AdaBoost), Gaussian naive Bayes and quadratic discriminant analysis] were used to classify each IIM subtype and select the most important metabolites as potential biomarkers.

RESULTS

OPLS-DA showed a clear separation between NC and IIM subtypes in plasma and urine metabolic profiles. KEGG pathway enrichment analysis revealed multiple unique and shared disturbed metabolic pathways in IIM main [dermatomyositis (DM), anti-synthetase syndrome (ASS), and immune-mediated necrotizing myopathy (IMNM)] and MSA-defined subtypes (anti-Mi2+, anti-MDA5+, anti-TIF1γ+, anti-Jo1+, anti-PL7+, anti-PL12+, anti-EJ+, and anti-SRP+), such that fatty acid biosynthesis was significantly altered in both plasma and urine in all main IIM subtypes (enrichment ratio > 1). Random forest and AdaBoost performed best in classifying each IIM subtype among the 10 ML models. Using the feature selection methods in ML models, we identified 9 plasma and 10 urine metabolites that contributed most to separate IIM main subtypes and MSA-defined subtypes, such as plasma creatine (fold change = 3.344, P = 0.024) in IMNM subtype and urine tiglylcarnitine (fold change = 0.351, P = 0.037) in anti-EJ+ ASS subtype. Sixteen common metabolites were found in both the plasma and urine samples of IIM subtypes. Among them, some were correlated with clinical features, such as plasma hypogeic acid (r = -0.416, P = 0.005) and urine malonyl carnitine (r = -0.374, P = 0.042), which were negatively correlated with the prevalence of interstitial lung disease.

CONCLUSIONS

In both plasma and urine samples, IIM main and MSA-defined subtypes have specific metabolic signatures and pathways. This study provides useful clues for understanding the molecular mechanisms, searching potential diagnosis biomarkers and therapeutic targets for IIM.

UCP1 Knockin Induces Lipid Dynamics and Transcriptional Programs in the Skeletal Muscles of Pigs

Uncoupling protein 1 (UCP1), the hallmark protein responsible for nonshivering thermogenesis in adipose tissue (especially brown adipose tissue) has regained researchers' attention in the context of metabolic disorders following the realization that UCP1 can be activated in adult humans and reconstituted in pigs. Both skeletal muscle and adipose tissue are highly dynamic tissues that interact at the metabolic and hormonal level in response to internal and external stress, and they coordinate in maintaining whole-body metabolic homeostasis. Here, we utilized lipidomics and transcriptomics to identify the altered lipid profiles and regulatory pathways in skeletal muscles from adipocyte-specific UCP1 knock-in (KI) pigs. UCP1 KI changed the contents of glycerophospholipids and acyl carnitines of skeletal muscles. Several metabolic regulatory pathways were more enriched in the UCP1 KI skeletal muscle. Comparison of the transcriptomes of adipose and skeletal muscle suggested that nervous system or chemokine signaling might account for the crosstalk between these two tissues in UCP1 KI pigs. Comparison of the lipid biomarkers from UCP1 KI pigs and other mammals suggested associations between UCP1 KI-induced metabolic alternations and metabolic and muscle dysfunction. Our study reveals the lipid dynamics and transcriptional programs in the skeletal muscle of UCP1 KI pigs and suggests that a network regulates metabolic homeostasis between skeletal muscle and adipose tissue.

Assessment and management of the heightened risk for atherosclerotic cardiovascular events in patients with lupus erythematosus or dermatomyositis

For patients with lupus erythematosus (LE) or dermatomyositis (DM), there is an urgent need to address a heightened risk of clinical events, chiefly heart attacks and strokes, caused by atherosclerotic cardiovascular disease (ASCVD). Patients with LE or DM frequently exhibit high levels of conventional risk factors for ASCVD events, particularly dyslipoproteinemia and hypertension; an amplified burden of atherosclerotic plaques; and increased age- and sex-adjusted rates of ASCVD events compared with the general population. The rate of ASCVD events exceeds what would be expected from conventional risk factors, suggesting that disease-specific autoimmune processes exacerbate specific, known pathogenic steps in atherosclerosis. Importantly, despite their heightened risk, patients with LE or DM are often undertreated for known causative agents and exacerbators of ASCVD. Herein, we propose an approach to assess and manage the heightened risk of ASCVD events in patients with LE or DM. Our approach is modeled in large part on established approaches to patients with diabetes mellitus or stage 3 or 4 chronic kidney disease, which are well-studied conditions that also show heightened risk for ASCVD events and have been explicitly incorporated into standard clinical guidelines for ASCVD. Based on the available evidence, we conclude that patients with LE or DM require earlier and more aggressive screening and management of ASCVD. We suggest that physicians consider implementing multipliers of conventional risk calculators to trigger earlier initiation of lifestyle modifications and medical therapies in primary prevention of ASCVD events, employ vascular imaging to quantify the burden of subclinical plaques, and treat to lower lipid targets using statins and newer therapies, such as PCSK9 inhibitors, that decrease ASCVD events in nonautoimmune cohorts. More clinical vigilance is needed regarding surveillance, prevention, risk modification, and treatment of dyslipidemias, hypertension, and smoking in patients with LE or DM. All of these goals are achievable.

Cardiovascular Health in Pediatric Rheumatologic Diseases

Cardiovascular disease risk is evident during childhood for patients with juvenile systemic lupus erythematosus, juvenile dermatomyositis, and juvenile idiopathic arthritis. The American Heart Association defines cardiovascular health as a positive health construct reflecting the sum of protective factors against cardiovascular disease. Disease-related factors such as chronic inflammation and endothelial dysfunction increase cardiovascular disease risk directly and through bidirectional relationships with poor cardiovascular health factors. Pharmacologic and nonpharmacologic interventions to improve cardiovascular health and long-term cardiovascular outcomes in children with rheumatic disease are needed.

Changes in Plasma Phospholipid Metabolism Are Associated with Clinical Manifestations of Systemic Sclerosis

Systemic sclerosis (SSc) is an autoimmune disease with fibrosis of the skin and/or internal organs, causing a decrease in quality of life and survival. There is no causative therapy, and the pathophysiology of the SSc remains unclear. Studies showed that lipid metabolism was relevant for autoimmune diseases, but little is known about the role of lipids in SSc. In the present study, we sought to explore the phospholipid profile of SSc by using the lipidomics approach. We also aimed to analyze lipidomics results for different clinical manifestations of SSc. Experiments were performed using high-performance liquid chromatography coupled to mass spectrometry for the lipidomic profiling of plasma samples from patients with SSc. Our study showed, for the first time, significant changes in the level of phospholipids such as plasmalogens and sphingomyelins from the plasma of SSc patients as compared to controls. Phosphatidylcholine plasmalogens species and sphingomyelins were significantly increased in SSc patients as compared to controls. Our results also demonstrated a significant association of changes in the metabolism of phospholipids (phosphatidylcholine and phosphatidylethanolamine plasmalogens species and sphingomyelins) with different clinical manifestations of SSc. Further lipidomic studies might lead to the detection of lipids as new biomarkers or therapeutic targets of SSc.

Metabolomics Analysis Identifies a Lipidomic Profile in Treatment Naïve Juvenile Dermatomyositis Patients versus Healthy Control Subjects

Objectives

To perform an exploratory study to identify a JDM serum metabolic profile that differs from healthy controls (HCs) and responds to immunosuppressive treatment.

Methods

Blood was collected from 9 HCs and 10 patients diagnosed with probable (n = 4) or definite (n = 6) JDM based on the criteria of Bohan and Peter for myositis, with 7 of the 10 providing longitudinal samples following initiation of treatment; these patients comprised the treatment-naïve cohort. Sera underwent mass spectroscopy–based measurements of targeted metabolic intermediates, including 15 amino acids, 45 acylcarnitines (ACs), 15 ceramides and 29 sphingomyelins. Principal components analysis reduced metabolites into smaller sets of factors each comprised of correlated metabolic intermediates. Factor scores and metabolite concentrations were compared with HCs using two-sample t-tests while treatment effects were evaluated using paired t-tests.

Results

Of eight principal components analysis–derived metabolite factors (one AC, two amino acids, three sphingosine and two ceramide), two were significantly associated with JDM: one AC factor containing mostly long-chain ACs (P = 0.049) and one ceramide factor (P < 0.01). For 12 individual ACs, mostly long chain, and three ceramides, concentrations were significantly greater for JDM than HCs. Factors based on these individual metabolites showed decreasing scores with treatment (P = 0.03 and P < 0.01, respectively).

Conclusion

While additional validation is needed, these lipids have potential as JDM serum diagnostic and/or treatment biomarkers. Additionally, the significant association of long-chain ACs and ceramides with JDM offers insights regarding pathogenesis, implicating dysregulation of mitochondrial fatty acid β-oxidation.

Clinical Characteristics of Lipid Metabolism in Untreated Patients with Anti-MDA5 Antibody-Positive

Objective

Clinical characterization of lipid metabolism in untreated patients with anti-melanoma differentiation-associated gene 5 antibodies-positive (anti-MDA5⁺).

Methods

Body-mass index (BMI), autoantibodies, lipid levels, and serum ferritin levels in 57 anti-MDA5⁺ patients were determined in the Department of Rheumatology and Immunology of the Second Affiliated Hospital of Chongqing Medical University.

Results

Plasma high-density lipoprotein (HDL) and apolipoprotein A1 (ApoA1) levels were significantly lower in deceased group than in the survival group (P < 0.05). Plasma levels of HDL and ApoA1 were significantly lower in patients who were simultaneously anti-MDA5⁺ and anti-Ro-52⁺ than in patients who were anti-MDA5⁺ alone (P < 0.05). Plasma levels of total cholesterol, low-density lipoprotein, HDL, and ApoA1 were significantly decreased in patients with high levels of serum ferritin compared with patients with low levels (P < 0.05). There were no significant differences in blood lipid levels between patients grouped according to BMI.

Conclusion

1) HDL and ApoA1 levels are important indicators of poor prognosis in anti-MDA5⁺ patients; 2) Dysregulated lipid metabolism in anti-MDA5⁺ patients is closely associated with anti-Ro-52 antibody and ferritin levels but independent of BMI; 3) HDL involvement in inflammation and immune regulation merits close attention by rheumatologists.

Altered dynamics of lipid metabolism in muscle cells from patients with idiopathic inflammatory myopathy is ameliorated by 6 months of training

KEY POINTS

Regular exercise improves muscle functional capacity and clinical state of patients with idiopathic inflammatory myopathy (IIM). In our study, we used an in vitro model of human primary muscle cell cultures, derived from IIM patients before and after a 6-month intensive supervised training intervention to assess the impact of disease and exercise on lipid metabolism dynamics. We provide evidence that muscle cells from IIM patients display altered dynamics of lipid metabolism and impaired adaptive response to saturated fatty acid load compared to healthy controls. A 6-month intensive supervised exercise training intervention in patients with IIM mitigated disease effects in their cultured muscle cells, improving or normalizing their capacity to handle lipids. These findings highlight the putative role of intrinsic metabolic defects of skeletal muscle in the pathogenesis of IIM and the positive impact of exercise, maintained in vitro by yet unknown epigenetic mechanisms.

ABSTRACT

Exercise improves skeletal muscle function, clinical state and quality of life in patients with idiopathic inflammatory myopathy (IIM). Our aim was to identify disease-related metabolic perturbations and the impact of exercise in skeletal muscle cells of IIM patients. Patients underwent a 6-month intensive supervised training intervention. Muscle function, anthropometric and metabolic parameters were examined and muscle cell cultures were established (m. vastus lateralis; Bergström needle biopsy) before and after training from patients and sedentary age/sex/body mass index-matched controls. [¹⁴ C]Palmitate was used to determine fat oxidation and lipid synthesis (thin layer chromatography). Cells were exposed to a chronic (3 days) and acute (3 h) metabolic challenge (the saturated fatty acid palmitate, 100 μm). Reduced oxidative (intermediate metabolites, -49%, P = 0.034) and non-oxidative (diglycerides, -38%, P = 0.013) lipid metabolism was identified in palmitate-treated muscle cells from IIM patients compared to controls. Three days of palmitate exposure elicited distinct regulation of oxidative phosphorylation (OxPHOS) complex IV and complex V/ATP synthase (P = 0.012/0.005) and adipose triglyceride lipase in patients compared to controls (P = 0.045) (immunoblotting). Importantly, 6 months of training in IIM patients improved lipid metabolism (CO₂ , P = 0.010; intermediate metabolites, P = 0.041) and activation of AMP kinase (P = 0.007), and nearly normalized palmitate-induced changes in OxPHOS proteins in myotubes from IIM patients, in parallel with improvements of patients' clinical state. Myotubes from IIM patients displayed altered dynamics of lipid metabolism and impaired response to metabolic challenge with saturated fatty acid. Our observations suggest that metabolic defects intrinsic to skeletal muscle could represent non-immune pathomechanisms, which can contribute to muscle weakness in IIM. A 6-month training intervention mitigated disease effects in muscle cells in vitro, indicating the existence of epigenetic regulatory mechanisms.

The altered metabolism profile in pathogenesis of idiopathic inflammatory myopathies

Idiopathic inflammatory myopathies (IIMs) are a group of heterogeneous autoimmune diseases characterized by muscle weakness, muscle inflammation and extramuscular manifestations. Despite extensive efforts, the mechanisms of IIMs remain largely unknown, and treatment is still a challenge for physicians. Metabolism changes have emerged as a crucial player in autoimmune diseases, such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). However, little is known about metabolism changes in IIMs. In this review, we focus on the alteration of metabolism profile in IIMs, and the relationships with clinical information. We highlight the potential roles of metabolism in the pathogenesis of IIMs and discuss future perspectives for metabolic checkpoint-based therapeutic interventions.

Profiling analysis of phospholipid fatty acids in serum as a complement to the comprehensive fatty acids method

Fatty acids (FAs) are mostly found in blood as triglycerides, phospholipids (PLs) and cholesteryl esters. Determination of FAs is typically carried out in serum or plasma by a comprehensive method (known as the classical FAMEs method since FAs are determined as Fatty Acids Methyl Esters), which is based on liquid-liquid extraction, derivatization by transesterification, and determination by gas chromatography (GC) coupled to a suited detection technique. However, this method does not favor the determination of FAs that are chemically conjugated in PLs due to kinetics impediment. For this reason, we have developed a selective method to determine the FAs profile of PLs in serum based on solid-phase extraction (SPE) for isolation of PLs and determination of the FAME derivatives by GC-mass spectrometry (GC-MS). The method was applied to serum samples collected from twenty-five individuals to compare the FAs profile versus that provided by the non-selective protocol based on liquid-liquid extraction of lipid families. Statistical analysis revealed compositional changes in the FAs profile with special emphasis on the content of saturated (SFAs) and monounsaturated FAs (MUFAs). Thus, SFAs passed from 34.0% with the classical method to 49.3% in PLs while MUFAs went from 24.4% to 11.4%. This study proves that the proposed method provides complementary results to the comprehensive method and, therefore, both methods can be combined to evaluate the effect of intervention diets and their connection to metabolic diseases.

The Influence of Dietary Fatty Acids on Immune Responses

Diet-derived fatty acids (FAs) are essential sources of energy and fundamental structural components of cells. They also play important roles in the modulation of immune responses in health and disease. Saturated and unsaturated FAs influence the effector and regulatory functions of innate and adaptive immune cells by changing membrane composition and fluidity and by acting through specific receptors. Impaired balance of saturated/unsaturated FAs, as well as n-6/n-3 polyunsaturated FAs has significant consequences on immune system homeostasis, contributing to the development of many allergic, autoimmune, and metabolic diseases. In this paper, we discuss up-to-date knowledge and the clinical relevance of the influence of dietary FAs on the biology, homeostasis, and functions of epithelial cells, macrophages, dendritic cells, neutrophils, innate lymphoid cells, T cells and B cells. Additionally, we review the effects of dietary FAs on the pathogenesis of many diseases, including asthma, allergic rhinitis, food allergy, atopic dermatitis, rheumatoid arthritis, multiple sclerosis as well as type 1 and 2 diabetes.

Inhibition of mPGES-1 or COX-2 Results in Different Proteomic and Lipidomic Profiles in A549 Lung Cancer Cells

Pharmacological inhibition of microsomal prostaglandin E synthase (mPGES)-1 for selective reduction in prostaglandin E₂ (PGE₂) biosynthesis is protective in experimental models of cancer and inflammation. Targeting mPGES-1 is envisioned as a safer alternative to traditional non-steroidal anti-inflammatory drugs (NSAIDs). Herein, we compared the effects of mPGES-1 inhibitor Compound III (CIII) with the cyclooxygenase (COX)-2 inhibitor NS-398 on protein and lipid profiles in interleukin (IL)-1β-induced A549 lung cancer cells using mass spectrometry. Inhibition of mPGES-1 decreased PGE₂ production and increased PGF_2α and thromboxane B₂ (TXB₂) formation, while inhibition of COX-2 decreased the production of all three prostanoids. Our proteomics results revealed that CIII downregulated multiple canonical pathways including eIF2, eIF4/P70S6K, and mTOR signaling, compared to NS-398 that activated these pathways. Moreover, pathway analysis predicted that CIII increased cell death of cancer cells (Z = 3.8, p = 5.1E-41) while NS-398 decreased the same function (Z = -5.0, p = 6.5E-35). In our lipidomics analyses, we found alterations in nine phospholipids between the two inhibitors, with a stronger alteration in the lysophospholipid (LPC) profile with NS-398 compared to CIII. Inhibition of mPGES-1 increased the concentration of sphinganine and dihydroceramide (C_16:0DhCer), while inhibition of COX-2 caused a general decrease in most ceramides, again suggesting different effects on cell death between the two inhibitors. We showed that CIII decreased proliferation and potentiated the cytotoxic effect of the cytostatic drugs cisplatin, etoposide, and vincristine when investigated in a live cell imaging system. Our results demonstrate differences in protein and lipid profiles after inhibition of mPGES-1 or COX-2 with important implications on the therapeutic potential of mPGES-1 inhibitors as adjuvant treatment in cancer. We encourage further investigations to illuminate the clinical benefit of mPGES-1 inhibitors in cancer.