During development, a group of cells called organizers plays critical roles by sending signals to adjacent cells and controlling embryonic and tissue patterning. Recent studies suggest that these inductive cells facilitate the downstream signaling pathways conserved across organisms. However, what makes these cells fundamentally inductive is little understood. In this study, we demonstrate that the micromeres of the sea urchin, one of the known organizers, have distinct metabolic properties compared to the rest of the embryo. The specific metabolic inhibitors for sugar metabolism (2-DG), fatty acid synthesis (cerulenin), and N-linked glycosylation (tunicamycin) compromise micromeres' regulatory capacity, altering the downstream germ layer patterning in the resultant embryos. Notably, the endoplasmic reticulum (ER) asymmetrically localizes during asymmetric cell division, resulting in the enrichment of ER and Wnt protein at the vegetal cortex of micromeres. Metabolic inhibition appears to compromise ER activity in Wnt particle distribution. We propose that the micromere ER is sensitive to specific metabolic regulation, contributing to the inductive signaling activity. This study provides a paradigm of how ER and metabolic regulation contribute to the inductive capability of the cells.
© 2025. The Author(s).

Dietary fat composition has changed substantially during the obesity epidemic. As adipocyte hyperplasia is a major mechanism of adipose expansion, we aim to ascertain how dietary fats affect adipogenesis during obesity. We employ an unbiased dietary screen to identify oleic acid (OA) as the only dietary fatty acid that induces obesogenic hyperplasia at physiologic levels and show that plasma monounsaturated fatty acids (MUFAs), which are mostly OA, are associated with human obesity. OA stimulates adipogenesis in mouse and human adipocyte precursor cells (APCs) by increasing AKT2 signaling, a hallmark of obesogenic hyperplasia, and reducing LXR activity. High OA consumption decreases LXRα Ser196 phosphorylation in APCs, while blocking LXRα phosphorylation results in APC hyperproliferation. As OA is increasingly being incorporated into dietary fats due to purported health benefits, our finding that OA is a unique physiologic regulator of adipose biology underscores the importance of understanding how high OA consumption affects metabolic health.
Copyright © 2025 The Author(s). Published by Elsevier Inc. All rights reserved.

Twice-daily intake of purified eicosapentaenoic acid (EPA) reduces atherosclerotic cardiovascular disease risk in patients with high triglycerides, but its exact mechanism remains unclear. We exposed non-activated CD4+ T cells to 100μM EPA, oleic acid, palmitic acid, or control, and conducted RNA and ATAC-sequencing after 48 hours. EPA exposure downregulated immune response-related genes like HLA-DRA, CD69, and IL2RA, and upregulated oxidative stress prevention genes like NQO1. Transcription factor footprinting showed decreased GATA3 and PU.1, and increased REV-ERB. These effects were specific to EPA, suggesting it induces an anti-inflammatory transcriptomic landscape in CD4+ T cells, contributing to its observed cardiovascular benefits.
Copyright © 2025 The Authors. Published by Elsevier Inc. All rights reserved.

Patients with metastatic breast cancer face reduced quality of life and increased mortality rates, necessitating more effective anti-cancer strategies. Building on previous research that identified metastatic-niche-specific metabolic vulnerabilities, we investigated how a ketogenic diet enhances estrogen receptor (ER)-positive liver metastatic breast cancer's response to Fulvestrant (Fulv) treatment. Using in vitro cell lines and in vivo xenograft metastasis mouse models, we examined the molecular mechanisms of combining ER targeting with a ketogenic diet. We found that Fulv treatment downregulates the ketogenesis pathway enzyme OXCT1, leading to β-hydroxybutyrate accumulation and decreased tumor cell viability. We also explored interactions between glucose, palmitic acid, and β-hydroxybutyric acid. These findings establish the molecular basis and clinical potential of a ketogenic diet to enhance Fulv efficacy in patients with ER+ liver metastatic breast cancer, potentially improving survival outcomes and quality of life in this population.
© 2025. The Author(s).

Cyclooxygenase-2 (COX-2) catalyzes the oxidation of arachidonic acid (AA) into a single product that is the source of all prostaglandins (PGs), ligands of multiple pro-inflammatory pathways. AA catalysis results in suicide inactivation, rendering the enzyme catalytically inactive. Here, we report that catalytic activity also leads to controlled cleavage of COX-2, an event that is differentially regulated by fatty acids, and blocked by COX inhibitors. We also find COX-2 fragments in human colon tumors. Using mass spectrometry, we identified two adjacent cleavage points within the catalytic domain, which give rise to COX-2 fragments that are catalytically inactive and localize to different cellular compartments. Expression of one of these fragments in cells significantly reduced mitochondrial function, increased lactate production, and enhanced proliferation. We propose that in addition to its role in generating PGs, COX-2 has PG-independent cellular functions that may account for its complex role in proliferative diseases and chronic inflammation.
© 2024 The Authors.