Publications

Background: Acquired resistance to tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer (NSCLC) is a critical clinical barrier. While metabolic reprogramming is implicated in target-independent resistance, the specific role of triglyceride (TG) synthesis remains unclear. Objective: This study aims to systematically elucidate the precise role and underlying mechanisms of LPIN2-mediated lipid metabolic reprogramming in TKI resistance, and to explore potential metabolic-targeted combination therapies for NSCLC. Methods: Osimertinib-resistant (PC-9 OR) and alectinib-resistant (NCI-H3122 ALR) cell lines were established via a dose-escalation strategy. The resistant cells were then compared with their original sensitive cells under both drug-present and drug-withdrawn conditions. Metabolomic liquid chromatography-mass spectrometry (LC-MS) and transcriptomic analyses revealed shared differential features, which were selected as candidate key metabolic enzymes in TKI resistance. From this pathway, LPIN2 was selected as a consistently upregulated key enzyme for validation. The LPIN2 gene was knocked out using CRISPR/Cas9 technology; a series of functional assays (e.g., drug sensitivity, colony formation), complemented by lipid supplementation, pathway inhibition (PI3K/mTOR), and a mouse xenograft model to verify the underlying mechanism. Results: LPIN2 was identified as a key driver of TKI resistance in NSCLC, with its mRNA and protein levels significantly upregulated (~2-fold) in osimertinib-resistant (PC-9 OR) and alectinib-resistant (NCI-H3122 ALR) cells. CRISPR/Cas9-mediated LPIN2 knockout restored TKI sensitivity, displaying oncogene-specific magnitudes of reduction in the half-maximal inhibitory concentration (IC50): decreasing from 3,585 nM to 229-477 nM in EGFR-mutant PC-9 OR cells, and exhibiting a more moderate reduction from 2,264 nM to 325-488 nM in ALK-fusion NCI-H3122 ALR cells, while suppressing tumor growth in vivo (Ki67 downregulation). Mechanistically, LPIN2 promoted TG accumulation and lipid droplet deposition; exogenous TG supplementation (1,2-dioleoyl-3-arachidoyl-sn-glycerol) induced TKI resistance in parental cells and rescued drug tolerance in LPIN2-knockout cells, whereas inhibition of downstream TG synthesis enzymes [diacylglycerol O-acyltransferase1/2 (DGAT1/2)] recapitulated the knockout phenotype. Furthermore, perturbation of the LPIN2-TG axis was associated with modulation of the PI3K-AKT-mTOR survival pathway, regulating apoptosis-related proteins (BCL-XL/BCL2 downregulation, BAX upregulation). Combined treatment with osimertinib and a PI3K inhibitor (Wortmannin) synergistically suppressed tumor growth and prolonged survival in xenograft models. Conclusions: LPIN2 contributes to TKI resistance in NSCLC through a novel LPIN2-TG metabolic node that is functionally associated with PI3K-AKT signaling: it enhances TG biosynthesis and lipid droplet accumulation, thereby indirectly modulating the PI3K-AKT pathway to inhibit apoptosis. Targeting this axis reverses TKI resistance in vitro and in vivo, identifying LPIN2 as a drug stress-independent resistance driver and potential biomarker for metabolic-targeted combination therapy.

JTD Keywords: Acquired-resistance, Cell lung-cancer, Driven, Fatty-acids, Lpin2, Metabolism, Non-small cell lung cancer (nsclc), Triglyceride metabolism (tg metabolism), Tyrosine kinase inhibitor resistance (tki resistance)

Short-chain fatty acids (SCFAs) are bacterial metabolites with crucial roles in host homeostasis and immune system modulation. Given their benefits, they have been proposed as markers of healthy microbiota. However, accurate SCFA quantification typically requires gas chromatography coupled with mass spectrometry (GC-MS), which is time-consuming, expensive, and requires specialized personnel and equipment, limiting its routine use for stool quality assessment in clinical contexts. In this initial feasibility study, we explored the use of Fourier transform infrared (FT-IR) spectroscopy as a rapid metabolic screening approach for stool samples. Analysis of SCFA-associated spectral windows enhanced discrimination between healthy and dysbiotic stool samples with Clostridioides difficile infection using principal component analysis. FT-IR is not intended to replace GC-MS for precise SCFA quantification but rather to provide a rapid screening of metabolically relevant differences. Although additional validation is still needed, the present study provides a robust proof-of-concept demonstrating the feasibility of applying FT-IR spectroscopy to clinical stool samples. Combined with the widespread availability of this technology in most hospitals, these advantages highlight its potential for future development as a tool for routine screening in clinical laboratories.

JTD Keywords: Bacteria, Chain fatty-acids, Dysbiosis, Fourier-transforminfrared spectroscopy, Microbiome, Short-chain fatty acids

Several pathogenic Escherichia coli strains cause diarrhea. Enteroaggregative E. coli (EAEC) strains are one of the diarrheagenic pathotypes. EAEC cells form a "stacked-brick" arrangement over the intestinal epithelial cells. EAEC isolates express, among other virulence determinants, the AggR transcriptional activator and the aggregative adherence fimbriae (AAF). Overexpression of the aggR gene results in increased expression of virulence factors such as the aff genes, as well as several genes involved in specific metabolic pathways such as fatty acid degradation (fad) and arginine degradation (ast). To support the hypothesis that induction of the expression of some of these pathways may play a role in EAEC virulence, in this study we used a murine infection model to evaluate the impact of the expression of these pathways on infection parameters. Mice infected with a mutant derivative of the EAEC strain 042, characterized by overexpression of the aggR gene, showed increased disease symptoms compared to those exhibited by mice infected with the wild type (wt) strain 042. Several of these symptoms were not increased when the infecting mutant, which overexpressed aggR, lacked the fad and ast pathways. Therefore, our results support the hypothesis that different metabolic pathways contribute to EAEC virulence.

JTD Keywords: Adherence, Aggr, Burde, Chain fatty-acids, Children, Enteroaggregative e. coli, Escherichia-coli, Etiology, Infection, Mice, Microbiota, Persistent diarrhea, Protein, Scfa, Sex-differences

A deficiency in omega-3 fatty acids ( to 3 FAs) in the brain has been correlated with cognitive impairment, learning deficiencies, and behavioral changes. In this study, we provided to 3 FAs as a supplement to spontaneously hypertensive rats (SHR+ to 3). Our focus was on examining the impact of dietary supplementation on the physicochemical properties of the brain-cell membranes. Significant increases in to 3 levels in the cerebral cortex of SHR+ to 3 were observed, leading to alterations in brain lipid membranes molecular packing, elasticity, and lipid miscibility, resulting in an augmented phase disparity. Results from synthetic lipid mixtures confirmed the disordering effect introduced by to 3 lipids, showing its consequences on the hydration levels of the monolayers and the organization of the membrane domains. These findings suggest that dietary to 3 FAs influence the organization of brain membranes, providing insight into a potential mechanism for the broad effects of dietary fat on brain health and disease.

JTD Keywords: Behavio, Bilayers, Docosahexaenoic acid, Metabolism, Molecular packing, Phosphatidylcholine, Phosphatidylethanolamine, Polyunsaturated fatty-acids, Raft, Spectroscopy, Sphingomyelin

Primary ventricular fibrillation (PVF) is a major driver of cardiac arrest in the acute phase of ST-segment elevation myocardial infarction (STEMI). Enrichment of cardiomyocyte plasma membranes with dietary polyunsaturated fatty acids (PUFA) reduces vulnerability to PVF experimentally, but clinical data are scarce. PUFA status in serum phospholipids is a valid surrogate biomarker of PUFA status in cardiomyocytes within a wide range of dietary PUFA. In this nested case-control study (n = 58 cases of STEMI-driven PVF, n = 116 control non-PVF STEMI patients matched for age, sex, smoking status, dyslipidemia, diabetes mellitus and hypertension) we determined fatty acids in serum phospholipids by gas-chromatography, and assessed differences between cases and controls, applying the Benjamini-Hochberg procedure on nominal P-values to control the false discovery rate (FDR). Significant differences between cases and controls were restricted to linoleic acid (LA), with PVF patients showing a lower level (nominal P = 0.002; FDR-corrected P = 0.027). In a conditional logistic regression model, each one standard deviation increase in the proportion of LA was related to a 42% lower prevalence of PVF (odds ratio = 0.58; 95% confidence interval, 0.37, 0.90; P = 0.02). The association lasted after the inclusion of confounders. Thus, regular consumption of LA-rich foods (nuts, oils from seeds) may protect against ischemia-driven malignant arrhythmias.

JTD Keywords: Arrhythmias, Fish-oil, Omega-3-fatty-acids, Sudden cardiac death