Resveratrol‐induced remodelling of myocellular lipid stores: A study in metabolically compromised humans

When Siberian hamsters are transferred from long summerlike days (LDs) to short winterlike days (SDs) they decrease their body weight, primarily as body fat. These SD-induced decreases in lipid stores are not uniform. Internally located white adipose tissue (WAT) pads are depleted preferentially of lipid, whereas the more externally located subcutaneous WAT pads are relatively spared. These data suggest a possible differential sympathetic neural control over catecholamine-induced lipolysis and that lipolytic rates are greater for internal vs. external WAT pads. Moreover, if these differential rates of lipolysis are due to differential sympathetic nervous system (SNS) drives on the pads, then fat pad-specific catecholaminergic innervation may exist. Therefore, we tested whether inguinal WAT (IWAT; an external pad) and epididymal WAT (EWAT; an internal pad) were innervated differentially. In addition, we tested whether norepinephrine (NE) turnover (TO) reflected the presumed greater SNS drive on EWAT vs. IWAT after SD exposure. Injections of fluorescent tract tracers [Fluoro-Gold or indocarbocyanine perchlorate (DiI)] demonstrated projections from the SNS ganglia T13-L3 to both fat pads. Retrograde labeling revealed a relatively separate pattern of distribution of labeled neurons in the ganglia projecting to each pad. In vivo anterograde transport of DiI resulted in labeling in both IWAT and EWAT that included staining around individual adipocytes and occasionally retrogradely labeled cells. The proportionately greater decrease in EWAT compared with IWAT mass after 5 wk of SD exposure was reflected in greater EWAT NE TO than found in their LD counterparts for this pad.(ABSTRACT TRUNCATED AT 250 WORDS)

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Drosophila PDGF/VEGF signaling from muscles to hepatocyte-like cells protects against obesity

eLife ◽

10.7554/elife.56969 ◽

2020 ◽

Vol 9 ◽

Cited By ~ 1

Author(s):

Arpan C Ghosh ◽

Sudhir Gopal Tattikota ◽

Yifang Liu ◽

Aram Comjean ◽

Yanhui Hu ◽

...

Keyword(s):

Adipose Tissue ◽

Lipid Level ◽

Lipid Synthesis ◽

Tissue Lipid ◽

Tor Signaling ◽

Specific Expression ◽

Signaling Axis ◽

Organ Specific ◽

Lipid Stores ◽

Multicellular Organisms

PDGF/VEGF ligands regulate a plethora of biological processes in multicellular organisms via autocrine, paracrine, and endocrine mechanisms. We investigated organ-specific metabolic roles of Drosophila PDGF/VEGF-like factors (Pvfs). We combine genetic approaches and single-nuclei sequencing to demonstrate that muscle-derived Pvf1 signals to the Drosophila hepatocyte-like cells/oenocytes to suppress lipid synthesis by activating the Pi3K/Akt1/TOR signaling cascade in the oenocytes. Functionally, this signaling axis regulates expansion of adipose tissue lipid stores in newly eclosed flies. Flies emerge after pupation with limited adipose tissue lipid stores and lipid level is progressively accumulated via lipid synthesis. We find that adult muscle-specific expression of pvf1 increases rapidly during this stage and that muscle-to-oenocyte Pvf1 signaling inhibits expansion of adipose tissue lipid stores as the process reaches completion. Our findings provide the first evidence in a metazoan of a PDGF/VEGF ligand acting as a myokine that regulates systemic lipid homeostasis by activating TOR in hepatocyte-like cells.

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Studies on polyenoic acid incorporation into human platelet lipid stores: interactions with linoleic and arachidonic acids

Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism ◽

10.1016/0005-2760(86)90307-3 ◽

1986 ◽

Vol 877 (2) ◽

pp. 299-304 ◽

Cited By ~ 16

Author(s):

Mohamad Hajarine ◽

Michel Lagarde

Keyword(s):

Human Platelet ◽

Polyenoic Acid ◽

Acid Incorporation ◽

Arachidonic Acids ◽

Lipid Stores

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Long-term fasting and realimentation in hypogean and epigean isopods: a proposed adaptive strategy for groundwater organisms

Journal of Experimental Biology ◽

10.1242/jeb.205.14.2079 ◽

2002 ◽

Vol 205 (14) ◽

pp. 2079-2087 ◽

Cited By ~ 2

Author(s):

Frédéric Hervant ◽

David Renault

Keyword(s):

Metabolic Response ◽

Large Body ◽

Adaptive Strategy ◽

Energy System ◽

Adaptive Responses ◽

Rapid Restoration ◽

Surface Dwelling ◽

Unpredictable Environment ◽

Lipid Stores

SUMMARYThe effects of long-term fasting and subsequent refeeding on digestive physiology and energy metabolism were investigated in a subterranean aquatic crustacean, Stenasellus virei, and in a morphologically similar surface-dwelling species, Asellus aquaticus. Metabolic response to food deprivation was monophasic in A. aquaticus, with an immediate,large decrease in all energy reserves. In contrast, S. vireidisplayed three successive periods of phosphageno-glucidic, lipidic and,finally, proteo-lipidic-dominant catabolism over the course of the nutritional stress. To represent the responses of subterranean crustaceans to food stress and renutrition, a sequential energy strategy was hypothesized, suggesting that four successive phases (called stress, transition, adaptation and recovery) can be distinguished. Based on these results, a general adaptive strategy for groundwater organisms was proposed. Their remarkable resistance to long-term fasting may be partly explained by (1) a depressed metabolism,during which they mainly subsist on lipid stores, (2) a prolonged state of glycogen- and protein-sparing, (3) low energetic requirements and (4) large body stores. In addition, these groundwater species displayed high recovery abilities during refeeding, showing an optimal utilization of available food and a rapid restoration of their body reserves. These adaptive responses might be considered for numerous subterranean organisms as an efficient energy-saving strategy in a harsh and unpredictable environment where fasting(and/or hypoxic) periods of variable duration alternate with sporadic feeding events (and/or normoxic periods). Therefore, food-limited and/or hypoxia-tolerant groundwater species appear to be good examples of animals representing a low-energy system.

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Coordinate mobilization and burning of lipid stores. Focus on “Protein kinase A induces UCP1 expression in specific adipose depots to increase energy expenditure and improve metabolic health”

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00209.2016 ◽

2016 ◽

Vol 311 (1) ◽

pp. R10-R11

Author(s):

Matthew J. Brady

Keyword(s):

Protein Kinase ◽

Energy Expenditure ◽

Protein Kinase A ◽

Metabolic Health ◽

Increase Energy Expenditure ◽

Ucp1 Expression ◽

Lipid Stores ◽

Kinase A

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Redirection of SKN-1 abates the negative metabolic outcomes of a perceived pathogen infection

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1909666116 ◽

2019 ◽

Vol 116 (44) ◽

pp. 22322-22330 ◽

Cited By ~ 11

Author(s):

James D. Nhan ◽

Christian D. Turner ◽

Sarah M. Anderson ◽

Chia-An Yen ◽

Hans M. Dalton ◽

...

Keyword(s):

Transcriptional Activity ◽

Mapk Signaling ◽

Host Responses ◽

Lipid Homeostasis ◽

Epigenetic Landscape ◽

C Elegans ◽

Metabolic Outcomes ◽

Cellular Defenses ◽

Pathogen Response ◽

Lipid Stores

Early host responses toward pathogens are essential for defense against infection. In Caenorhabditis elegans, the transcription factor, SKN-1, regulates cellular defenses during xenobiotic intoxication and bacterial infection. However, constitutive activation of SKN-1 results in pleiotropic outcomes, including a redistribution of somatic lipids to the germline, which impairs health and shortens lifespan. Here, we show that exposing C. elegans to Pseudomonas aeruginosa similarly drives the rapid depletion of somatic, but not germline, lipid stores. Modulating the epigenetic landscape refines SKN-1 activity away from innate immunity targets, which alleviates negative metabolic outcomes. Similarly, exposure to oxidative stress redirects SKN-1 activity away from pathogen response genes while restoring somatic lipid distribution. In addition, activating p38/MAPK signaling in the absence of pathogens, is sufficient to drive SKN-1–dependent loss of somatic fat. These data define a SKN-1– and p38-dependent axis for coordinating pathogen responses, lipid homeostasis, and survival and identify transcriptional redirection, rather than inactivation, as a mechanism for counteracting the pleiotropic consequences of aberrant transcriptional activity.

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White adipose tissue sensory nerve denervation mimics lipectomy-induced compensatory increases in adiposity

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00036.2005 ◽

2005 ◽

Vol 289 (2) ◽

pp. R514-R520 ◽

Cited By ~ 40

Author(s):

Haifei Shi ◽

Timothy J. Bartness

Keyword(s):

Adipose Tissue ◽

Body Fat ◽

White Adipose Tissue ◽

Sensory Nerve ◽

Sensory Innervation ◽

Siberian Hamsters ◽

Total Body Fat ◽

Total Body ◽

Lipid Stores ◽

The Brain

The sensory innervation of white adipose tissue (WAT) is indicated by the labeling of sensory bipolar neurons in the dorsal root ganglion after retrograde dye placement into WAT. In addition, immunoreactivity (ir) for sensory-associated neuropeptides such as calcitonin gene-related peptide (CGRP) and substance P in WAT pads also supports the notion of WAT sensory innervation. The function of this sensory innervation is unknown but could involve conveying the degree of adiposity to the brain. In tests of total body fat regulation, partial surgical lipectomy triggers compensatory increases in the mass of nonexcised WAT, ultimately resulting in restoration of total body fat levels in Siberian hamsters and other animals. The signal that triggers this compensation is unknown but could involve disruption of WAT sensory innervation that accompanies lipectomy. Therefore, a local and selective sensory denervation was accomplished by microinjecting the sensory nerve neurotoxin capsaicin bilaterally into epididymal WAT (EWAT) of Siberian hamsters, whereas controls received vehicle injections. Additional hamsters had bilateral EWAT lipectomy (EWATx) or sham lipectomy. As seen previously, EWATx resulted in significantly increased retroperitoneal WAT (RWAT) and inguinal WAT (IWAT) masses. Capsaicin treatment significantly decreased CGRP- but not tyrosine hydroxylase-ir, attesting to the diminished and selective sensory innervation. Capsaicin-treated hamsters also had increased RWAT and, to a lesser degree, IWAT mass largely mimicking the WAT mass increases seen after lipectomy. Collectively, these data suggest the possibility that information related to peripheral lipid stores may be conveyed to the brain via the sensory innervation of WAT.

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