Regulation of Intestinal Stem Cell Proliferation by Enterocyte Mitochondrial Pyruvate Metabolism.

Multiple signaling pathways in the adult enterocyte sense cellular damage or stress and signal to intestinal stem cells (ISCs) to undergo proliferation and differentiation, thereby maintaining intestinal homeostasis. Here we show that misregulation of mitochondrial pyruvate metabolism in enterocytes can stimulate ISC proliferation and differentiation. Our studies focus on the Mitochondrial Pyruvate Carrier (MPC), which is an evolutionarily-conserved protein complex that resides in the inner mitochondrial membrane and transports cytoplasmic pyruvate into the mitochondrial matrix.

Functional analysis of Aarf domain-containing kinase 1 in Drosophila melanogaster.

Background: The ADCK proteins are predicted mitochondrial kinases. Most studies of these proteins have focused on the Abc1/Coq8 subfamily, which contributes to Coenzyme Q biosynthesis. In contrast, little is known about ADCK1 despite its evolutionary conservation in yeast, Drosophila, Caenorhabditis elegans and mammals.

Control of intestinal stem cell function and proliferation by mitochondrial pyruvate metabolism.

Most differentiated cells convert glucose to pyruvate in the cytosol through glycolysis, followed by pyruvate oxidation in the mitochondria. These processes are linked by the mitochondrial pyruvate carrier (MPC), which is required for efficient mitochondrial pyruvate uptake. In contrast, proliferative cells, including many cancer and stem cells, perform glycolysis robustly but limit fractional mitochondrial pyruvate oxidation.

An ancestral role for the mitochondrial pyruvate carrier in glucose-stimulated insulin secretion.

Objective: Transport of pyruvate into the mitochondrial matrix by the Mitochondrial Pyruvate Carrier (MPC) is an important and rate-limiting step in its metabolism. In pancreatic β-cells, mitochondrial pyruvate metabolism is thought to be important for glucose sensing and glucose-stimulated insulin secretion.

Methods: To evaluate the role that the MPC plays in maintaining systemic glucose homeostasis, we used genetically-engineered Drosophila and mice with loss of MPC activity in insulin-producing cells.

Defining the role of oxygen tension in human neural progenitor fate.

Hypoxia augments human embryonic stem cell (hESC) self-renewal via hypoxia-inducible factor 2α-activated OCT4 transcription. Hypoxia also increases the efficiency of reprogramming differentiated cells to a pluripotent-like state. Combined, these findings suggest that low O2 tension would impair the purposeful differentiation of pluripotent stem cells.

A host beetle pheromone regulates development and behavior in the nematode Pristionchus pacificus.

Nematodes and insects are the two most speciose animal phyla and nematode-insect associations encompass widespread biological interactions. To dissect the chemical signals and the genes mediating this association, we investigated the effect of an oriental beetle sex pheromone on the development and behavior of the nematode Pristionchus pacificus. We found that while the beetle pheromone is attractive to P.

Measuring energy metabolism in cultured cells, including human pluripotent stem cells and differentiated cells.

Measurements of glycolysis and mitochondrial function are required to quantify energy metabolism in a wide variety of cellular contexts. In human pluripotent stem cells (hPSCs) and their differentiated progeny, this analysis can be challenging because of the unique cell properties, growth conditions and expense required to maintain these cell types. Here we provide protocols for analyzing energy metabolism in hPSCs and their early differentiated progenies that are generally applicable to mature cell types as well.