A group 3 medulloblastoma stem cell program is maintained by OTX2-mediated alternative splicing.

OTX2 is a transcription factor and known driver in medulloblastoma (MB), where it is amplified in a subset of tumours and overexpressed in most cases of group 3 and group 4 MB. Here we demonstrate a noncanonical role for OTX2 in group 3 MB alternative splicing. OTX2 associates with the large assembly of splicing regulators complex through protein-protein interactions and regulates a stem cell splicing program.

Defining the mammalian coactivation of hepatic 12-h clock and lipid metabolism.

The 12-h clock coordinates lipid homeostasis, energy metabolism, and stress rhythms via the transcriptional regulator XBP1. However, the biochemical and physiological bases for integrated control of the 12-h clock and diverse metabolic pathways remain unclear. Here, we show that steroid receptor coactivator SRC-3 coactivates XBP1 transcription and regulates hepatic 12-h cistrome and gene rhythmicity.

XBP1 links the 12-hour clock to NAFLD and regulation of membrane fluidity and lipid homeostasis.

A distinct 12-hour clock exists in addition to the 24-hour circadian clock to coordinate metabolic and stress rhythms. Here, we show that liver-specific ablation of X-box binding protein 1 (XBP1) disrupts the hepatic 12-hour clock and promotes spontaneous non-alcoholic fatty liver disease (NAFLD). We show that hepatic XBP1 predominantly regulates the 12-hour rhythmicity of gene transcription in the mouse liver and demonstrate that perturbation of the 12-hour clock, but not the core circadian clock, is associated with the onset and progression of this NAFLD phenotype.

Vitamin D Receptor Activation in Liver Macrophages Ameliorates Hepatic Inflammation, Steatosis, and Insulin Resistance in Mice.

Background And Aims: Obesity-induced chronic inflammation is a key component in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) and insulin resistance. Increased secretion of proinflammatory cytokines by macrophages in metabolic tissues promotes disease progression. In the diet-induced obesity (DIO) mouse model, activation of liver resident macrophages, or Kupffer cells (KCs), drives inflammatory responses, which recruits circulating macrophages and promotes fatty liver development, and ultimately contributes to impaired hepatic insulin sensitivity.

Murine neonatal intravascular injections: modeling newborn disease.

The ability to perform murine neonatal intravascular injections likely will prove useful in studying many newborn-specific disease states that are modeled in mice. Unfortunately, effective intravascular injection in the neonatal mouse has been limited by developmental immaturity and small size. To establish a mouse model of neonatal intravascular injection, C57Bl/6 pups between birth and 6 d of age were injected with a buffered solution containing cells or vehicle alone.