# OM2, a Novel Oligomannuronate-Chromium(III) Complex, Promotes Mitochondrial Biogenesis and Lipid Metabolism in 3T3-L1 Adipocytes via the AMPK-PGC1α Pathway

## TL;DR

OM2, a new compound from marine alginate, boosts mitochondrial function and lipid metabolism in fat cells via the AMPK-PGC1α pathway, potentially aiding in diabetes treatment.

## Contribution

OM2 is a novel oligomannuronate-chromium(III) complex that activates the AMPK-PGC1α pathway to enhance mitochondrial biogenesis and lipid metabolism in adipocytes.

## Key findings

- OM2 activates the AMPK-PGC1α signaling pathway in 3T3-L1 adipocytes.
- OM2 increases mitochondrial biogenesis and improves mitochondrial function.
- OM2 reduces lipid accumulation through enhanced fatty acid β-oxidation and ATGL expression.

## Abstract

In our previous studies, we prepared novel oligomannuronate-chromium(III) complexes (OM2, OM4) from marine alginate, and found that these compounds sensitize insulin action better than oligomannuronate(OM), chromium, and metformin in C2C12 skeletal muscle cells. In the present study, we studied their effects on mitochondrial biogenesis, lipid metabolism, and the underlying molecular mechanisms in differentiated 3T3-L1 adipocytes.

We firstly used the pGL3-PGC1α and pGL3-ATGL promoter plasmids to compare their effects on PGC1α and ATGL transcription activities. Then mitochondrial biogenesis was quantified by transmission electron microscopy and MitoTracker staining. Mitochondrial oxygen consumption and fatty acid oxidation were measured by an oxygen biosensor system and ³H-labelled water scintillation. The mitochondrial DNA and mRNA involved in mitochondrial biogenesis and lipid oxidation were evaluated by real-time PCR. AMPK together with other protein expression levels were measured by western blotting. The inhibitor compound C and siRNA of PGC1α were used to inhibit the OM2-induced AMPK-PGC1α signaling pathway. And we found that OM2 stimulated AMPK-PGC1α pathway in the 3T3-L1 adipocytes, which were correlated with induced mitochondrial biogenesis, improved mitochondrial function, and reduced lipid accumulation by enhanced fatty acid β-oxidation and augmented ATGL protein expression.

Our data indicated that the marine oligosaccharide-derived OM2 might represent a novel class of molecules that could be useful for type 2 diabetes prevention and treatment by up-regulating AMPK-PGC1α signaling pathway.