Biology subjects

Gavrilova, O.

Publications and source records attributed to Gavrilova, O..

3 recordsLinked to original sources

bioRxiv2021

Preoptic BRS3 neurons increase body temperature and heart rate via multiple pathways

The preoptic area (POA) is a key region controlling body temperature (Tb), dictating thermogenic, cardiovascular, and behavioral responses to regulate Tb. Known POA neuronal populations reduce Tb when activated; a population that increases Tb upon activation has not yet been reported. We now identify bombesin-like receptor 3 (BRS3)-expressing POA (POABRS3) neurons as having this missing functionality. BRS3 is an orphan receptor that regulates energy and cardiovascular homeostasis, but the relevant neural circuits are incompletely understood. In mice, we demonstrate that POABRS3 neuronal activation increases Tb, heart rate, and blood pressure sympathetically, via projections to the paraventricular nucleus of the hypothalamus and dorsomedial hypothalamus. Acute POABRS3 inhibition reduces Tb. Long-term inactivation of POABRS3 neurons increased Tb variability with exaggerated Tb changes, overshooting both increases and decreases in Tb set point. BRS3 marks preoptic populations that regulate Tb and heart rate, contribute to cold-defense and fine-tune feedback control of Tb. These findings advance understanding of homeothermy, a defining feature of mammalian biology. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/433948v1_ufig1.gif" ALT="Figure 1"> View larger version (52K): org.highwire.dtl.DTLVardef@121b5a8org.highwire.dtl.DTLVardef@1d67bforg.highwire.dtl.DTLVardef@865eeborg.highwire.dtl.DTLVardef@1c1d41e_HPS_FORMAT_FIGEXP M_FIG Graphical abstract C_FIG

neuroscience↗

bioRxiv2020

MED1 is a lipogenesis coactivator required for postnatal adipose expansion

MED1 often serves as a surrogate of the general transcription coactivator complex Mediator for identifying active enhancers. MED1 is required for phenotypic conversion of fibroblasts to adipocytes in vitro but its role in adipose development and expansion in vivo has not been reported. Here we report that MED1 is dispensable for adipose development in mice. Instead, MED1 is required for postnatal adipose expansion and the induction of de novo lipogenesis (DNL) genes after pups switch diet from high-fat maternal milk to carbohydrate-based chow. During adipogenesis, MED1 is dispensable for induction of lineage-determining transcription factors (TFs) PPAR{gamma} and C/EBP but is required for lipid accumulation in the late phase of differentiation. Mechanistically, MED1 controls the induction of DNL genes by facilitating lipogenic TF ChREBP-dependent recruitment of Mediator to active enhancers. Together, our findings identify a cell- and gene-specific regulatory role of MED1 as a lipogenesis coactivator required for postnatal adipose expansion. O_LIMED1 is largely dispensable for adipogenesis and embryonic development of adipose tissue C_LIO_LIMED1 is required for postnatal adipose expansion C_LIO_LIMED1 is required for DNL gene expression in adipocytes C_LIO_LIMED1 controls DNL gene transcription by facilitating ChREBP-dependent Mediator binding to active enhancers C_LI

developmental biology↗

bioRxiv2020

Lack of Adipocyte Purinergic P2Y6 Receptor Greatly Improves Whole Body Glucose Homeostasis

Uridine diphosphate (UDP)-activated purinergic receptor P2Y6 (P2Y6R) plays a crucial role in controlling energy balance through central mechanisms. However, P2Y6Rs roles in peripheral tissues regulating energy and glucose homeostasis remain unexplored. Here, we report the surprising novel finding that adipocyte-specific deletion of P2Y6R protects mice from diet-induced obesity, improving glucose tolerance and insulin sensitivity with reduced systemic inflammation. These changes were associated with reduced JNK signaling, and enhanced expression and activity of PPAR affecting downstream PGC1 levels leading to beiging of white fat. In contrast, P2Y6R deletion in skeletal muscle reduced glucose uptake resulting in impaired glucose homeostasis. Interestingly, whole body P2Y6R KO mice showed metabolic improvements similar to those observed with mice lacking P2Y6R only in adipocytes. Our findings provide compelling evidence that P2Y6R antagonists may prove useful for the treatment of obesity and type 2 diabetes.

physiology↗