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Torpor is an energy-conserving state in which animals dramatically decrease their metabolic rate and body temperature to survive harsh environmental conditions. Here, we report the noninvasive, precise and safe induction of a torpor-like hypothermic and hypometabolic state in rodents by remote transcranial ultrasound stimulation at the hypothalamus preoptic area (POA). We achieve a long-lasting (>24 h) torpor-like state in mice via closed-loop feedback control of ultrasound stimulation with automated detection of body temperature. Ultrasound-induced hypothermia and hypometabolism (UIH) is triggered by activation of POA neurons, involves the dorsomedial hypothalamus as a downstream brain region and subsequent inhibition of thermogenic brown adipose tissue. Single-nucleus RNA-sequencing of POA neurons reveals TRPM2 as an ultrasound-sensitive ion channel, the knockdown of which suppresses UIH. We also demonstrate that UIH is feasible in a non-torpid animal, the rat. Our findings establish UIH as a promising technology for the noninvasive and safe induction of a torpor-like state.

Dysfunctional adipose tissue is believed to promote the development of hepatic steatosis and systemic insulin resistance, but many of the mechanisms involved are still unclear. Lipin 1 catalyzes the conversion of phosphatidic acid to diacylglycerol (DAG), the penultimate step of triglyceride synthesis, which is essential for lipid storage. Herein we found that adipose tissue LPIN1 expression is decreased in people with obesity compared to lean subjects and low LPIN1 expression correlated with multi-tissue insulin resistance and increased rates of hepatic de novo lipogenesis. Comprehensive metabolic and multi-omic phenotyping demonstrated that adipocyte-specific Lpin1-/- mice had a metabolically-unhealthy phenotype, including liver and skeletal muscle insulin resistance, hepatic steatosis, increased hepatic de novo lipogenesis, and transcriptomic signatures of nonalcoholic steatohepatitis that was exacerbated by high-fat diets. We conclude that adipocyte lipin 1-mediated lipid storage is vital for preserving adipose tissue and systemic metabolic health and its loss predisposes mice to nonalcoholic steatohepatitis.

Crohn’s disease [CD] is one of the two most common forms of inflammatory bowel disease, affecting over half a million Americans. Like many other diseases with chronic inflammation, some patients with CD develop tertiary lymphoid organs [TLO] in areas of the gastrointestinal tract with active disease. TLOs are organized clusters of lymphocytes, similar in structure to secondary lymphoid organs, though they develop after birth and their contribution to pathogenesis in CD, or other diseases, is unclear. We, and others, have also found B cell rich lymphoid aggregates in the mesenteric fat of CD patients along dramatically remodeled lymphatic vessels. TNFΔARE/+ is a murine model of ileal inflammation that recapitulates several key features of ileal CD, including development of mesenteric tertiary lymphoid organs. Use of this model revealed that mesenteric TLOs block cellular and molecular export from the gut, leading us to wonder if mechanisms that interfere with their development might reduce ileitis. TNFΔARE/+ mice that lack B cells revealed that B cells are required for tertiary lymphoid organ formation in this model. Without these TLOs, lymphatic outflow from the intestine was restored. Nonetheless, histological and flow cytometric approaches reveal no difference in local inflammation in the ileum. However, systemic inflammation, as assessed by metabolic cages and changes in body weight over time, increased. This suggests that TLOs may act to trap inflammatory signals locally, preventing systemic dissemination of inflammatory cells or mediators. Work supported by NIH grants DP1-DK109668-04 and T32-DK077653-27 and the Kenneth Rainin Foundation