Adipose Inositol Monophosphate Metabolism Is Associated with Fasting Regimen-Elicited Metabolic Benefits

TL;DR

Intermittent fasting increases inositol monophosphates in fat tissue, which may help explain its metabolic benefits like weight loss and better insulin sensitivity.

Contribution

The study identifies inositol monophosphate metabolism as a novel mechanism linking intermittent fasting to metabolic improvements.

Findings

Intermittent fasting elevates myo-inositol-1-phosphate and myo-inositol-3-phosphate in obese adipose tissue.

IF upregulates ITPK1 and IMPA1, enzymes involved in inositol monophosphate metabolism.

Increased inositol monophosphates correlate with reduced body weight and improved insulin sensitivity.

Abstract

Intermittent fasting (IF) has emerged as a promising strategy for managing obesity and related metabolic disorders. Although metabolic adaptations in adipose tissue during IF are well documented, the specific reprogramming of white adipose tissue (WAT) under prolonged cycles of fasting and refeeding remains incompletely understood. Using mass spectrometry-based approaches, including liquid chromatography (LC) and capillary electrophoresis (CE), we identified a marked increase in inositol monophosphates (InsP1s) in obese adipose tissue following extended IF. Specifically, myo-inositol-1-phosphate and myo-inositol-3-phosphate, which are typically present at low levels in gonadal WAT (gWAT) of diet-induced obese mice, were significantly elevated after 15 cycles of IF. Additionally, extended IF upregulated the expression levels of inositol tetrakisphosphate 1-kinase (ITPK1) and inositol monophosphatase 1 (IMPA1), two key enzymes involved in InsP1 metabolism. These increases coincide with reductions in body weight and fat mass, as well as improved insulin sensitivity. This reprogramming was further supported by enhanced tricarboxylic acid (TCA) cycle activity. Collectively, these findings suggest the inositol monophosphate pathway as a novel mechanism underlying fasting-induced metabolic adaptation in adipose tissue and highlight the potential of these metabolites as biomarkers for obesity and related metabolic conditions.

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