Energy Regulation

One man’s trash is another man’s treasure. In this study we identify a recycling mechanism by which muscle helps the body to get rid of a neurotoxic molecule (kynurenine) while using it to support energy production. This mechanism is induced by endurance exercise training and allows muscle cells to extract more energy from sugar, which enhances endurance exercise performance.

Exercise training is well known for increasing the energy our muscles use, reducing how much our adipose tissues stores, but also for changing our immune system. In this paper we found that during exercise, muscle secretes into circulation a small molecule (kynurenic acid) that activates a cell surface receptor (GPR35) in both fat cells and certain immune cells that reside in the adipose tissue. The result of this inter-organ communication is higher energy expenditure, and an anti-inflammatory state of the adipose tissue

Alternative splicing is a common process by which the same genetic information can be read (transcribed) in different ways, and produce different proteins, with potentially different activities. The bile acid receptor FXR is no exception, although it wasn’t known why cells are able to produce 4 different receptors from the same gene. We found that alternative splicing of the FXR gene can result in changes in liver metabolism that protect from hepatic fat accumulation

In this article we review the current understanding of how exercise and trained muscles can change the levels of compounds that result from the degradation of the amino acid tryptophan (they’re called kynurenines or kynurenine metabolites). There are several of these molecules and they can have diverse effects on the body. We also speculate on what directions this field might take in the future

We always think of neurons as the only important cells in our brain. But brain is a complex organ, with its own metabolic needs that are catered to by different cell types. Among them, astrocytes are the new hype.

The benefits of exercise are many. In these projects we try to uncover mediators of the positive adaptations to exercise to combat obesity.

Communication amongst organ systems is vital to keep everything in balance—sensory neurons and adipose tissue (fat) are no different. We think that the communication between sensory neurons and adipose tissue in obesity and diabetes is not working properly, and thus contributing to the metabolic dysfunction seen in these patients.