Spexin Friend or Foe? Novel Role of Spexin During Thermogenesis of White Adipose Tissue

Abstract Spexin (SPX) is a novel adipokine playing an emerging role in metabolic diseases due to its involvement in carbohydrate homeostasis, weight loss, appetite control, gastrointestinal movement, among others. Moreover, plasma levels are reduced in obese and type II diabetic patients. In vitro, SPX favors lipolysis in adipocytes and hepatocytes and inhibits white adipogenesis. Therefore, the aim of this study was to evaluate the role of SPX in white adipose tissue (AT) thermogenesis. C57BL/6J male mice were treated or not with SPX for ten days (ip. 29 µg/kg/day; CTR and SPX). At day 3 mice were randomly divided: a group was kept at room temperature (RT) and the other at 4°C to stimulate thermogenesis (CTR-C and SPX-C). Caloric intake and body weight was daily recorded. At the end of the protocol plasma, Brown AT (BAT), abdominal AT (Epidydimal, EAT) and subcutaneous AT (Inguinal, IAT) depots were collected for several measurements. We found that caloric intake was increased when animals were exposed to cold (P<0.001). Body weight change revealed a differential effect of SPX depending on temperature (interaction SPX x Cold, P<0.05): SPX animals weighted less than CTR at RT, but upon cold stimulation there was no difference. No changes were observed for plasma glucose levels, however plasma triglycerides (Tg) levels decreased after cold exposure regardless SPX treatment (Cold P<0.01). Liver Tg content showed a SPX x Cold interaction effect (P<0.0001), where, upon cold stimulation, CTR-C animals increased their levels, but on the contrary SPX-C mice decreased it. EAT, IAT and BAT relative mass showed an interaction effect of variables (SPX x Cold P<0.05). When compared upon cold, SPX-C mice had less AT mass compared to CTR-C mice. IAT and EAT mRNA expression of UCP1 and Cox8b showed SPX x Cold interaction (P<0.05), with a tendency of reduction or no difference in SPX at RT, but with a significant decrease in SPX-C compared to CTR-C mice upon cold exposure. PGC1a expression was increased in EAT from cold exposed-mice and in IAT only in CTR-C mice. UCP1 protein levels showed different results depending on the AT depot. For IAT SPX x Cold interaction (P<0.05) was observed, where SPX inhibited UCP1 stimulation only upon cold exposure. On the contrary, for EAT UCP1 levels decreased in SPX-treated mice, regardless cold exposure (SPX P<0.05). In conclusion, SPX treatment in vivo reduced the thermogenic process in subcutaneous and abdominal AT, being more evident upon cold stimulation. PICT2017-2038, PICT2017-2314.

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Insulin and metabolic efficiency in rats. II. Effects of NE and cold exposure

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1986.251.6.r1118 ◽

1986 ◽

Vol 251 (6) ◽

pp. R1118-R1125

Author(s):

T. J. Bartness ◽

C. J. Billington ◽

A. S. Levine ◽

J. E. Morley ◽

N. E. Rowland ◽

...

Keyword(s):

Body Weight ◽

Adipose Tissue ◽

Food Intake ◽

Energy Expenditure ◽

Cold Exposure ◽

Diabetic Rats ◽

Metabolic Efficiency ◽

Maximal Energy ◽

Brown Adipose

The role of insulin in metabolic efficiency (ME, i.e., efficiency of body wt gain) was examined under conditions of maximal energy expenditure in control and diabetic rats. Long-lasting insulin was administered using a protocol that did not affect food intake and increased ME in both groups. Half the animals were injected chronically with norepinephrine (NE). NE alone in controls decreased body weight and ME and increased brown adipose tissue (BAT) growth, thermogenic potential [cytochrome c oxidase activity (COA)], and lipoprotein lipases (LPL) activity; however, in diabetics, body weight, ME, and food intake all decreased and only BAT LPL activity and DNA content increased. The combination of NE and insulin increased BAT protein and COA in diabetics; in controls, all BAT measures were further increased and ME was intermediate to that of either treatment alone. Cold exposure decreased body weight and ME, increased food intake and qualitatively produced similar increases in BAT growth, COA, and LPL activity in both controls and diabetics. In diabetics, combined cold exposure and insulin did not affect the increase in BAT growth or LPL activity resulting from either treatment alone, but in controls this combination decreased BAT growth and COA. It is concluded that, even under conditions of maximal energy expenditure, both extremes of basal insulin status result in decreased BAT growth and thermogenic potential, but have opposite effects on ME.

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The involvement of neuroimmune cells in adipose innervation

10.21203/rs.3.rs-66882/v2 ◽

2020 ◽

Author(s):

Magdalena Blaszkiewicz ◽

Elizabeth Wood ◽

Sigi Koizar ◽

Jake Willows ◽

Ryan Anderson ◽

...

Keyword(s):

Adipose Tissue ◽

White Adipose Tissue ◽

Cold Exposure ◽

Immune Cells ◽

Neurotrophic Factors ◽

Neurotrophic Factor ◽

Stromal Vascular Fraction ◽

Proper Function ◽

Cold Stimulation ◽

Myeloid Lineage

Abstract Background: Innervation of adipose tissue is essential for the proper function of this critical metabolic organ. Numerous surgical and chemical denervation studies have demonstrated how maintenance of brain-adipose communication through both sympathetic efferent and sensory afferent nerves help regulate adipocyte size, cell number, lipolysis, and ‘browning’ of white adipose tissue. Neurotrophic factors are growth factors that promote neuron survival, regeneration, and plasticity, including neurite outgrowth and synapse formation. Peripheral immune cells have been shown to be a source of neurotrophic factors in humans and mice. Although a number of immune cells reside in the adipose stromal vascular fraction (SVF), it has remained unclear what roles they play in adipose innervation. We previously demonstrated that adipose SVF secretes brain derived neurotrophic factor (BDNF). Methods: We now show that deletion of this neurotrophic factor from the myeloid lineage of immune cells led to a ‘genetic denervation’ of inguinal subcutaneous white adipose tissue (scWAT), thereby causing decreased energy expenditure, increased adipose mass, and a blunted UCP1 response to cold stimulation. Results: We and others have previously shown that noradrenergic stimulation via cold exposure increases adipose innervation in the inguinal depot. Here we have identified a subset of myeloid cells that home to scWAT upon cold exposure and are Ly6C+ CCR2+ Cx3CR1+ monocytes/macrophages that express noradrenergic receptors and BDNF. This subset of myeloid lineage cells also clearly interacted with peripheral nerves in the scWAT and were therefore considered neuroimmune cells. Conclusions: We propose that these myeloid lineage, cold induced neuroimmune cells (CINCs) are key players in maintaining adipose innervation as well as promoting adipose nerve remodeling under noradrenergic stimulation, such as cold exposure.

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The involvement of neuroimmune cells in adipose innervation

Molecular Medicine ◽

10.1186/s10020-020-00254-3 ◽

2020 ◽

Vol 26 (1) ◽

Author(s):

Magdalena Blaszkiewicz ◽

Elizabeth Wood ◽

Sigi Koizar ◽

Jake Willows ◽

Ryan Anderson ◽

...

Keyword(s):

Adipose Tissue ◽

White Adipose Tissue ◽

Cold Exposure ◽

Immune Cells ◽

Neurotrophic Factors ◽

Neurotrophic Factor ◽

Stromal Vascular Fraction ◽

Proper Function ◽

Cold Stimulation ◽

Myeloid Lineage

Abstract Background Innervation of adipose tissue is essential for the proper function of this critical metabolic organ. Numerous surgical and chemical denervation studies have demonstrated how maintenance of brain-adipose communication through both sympathetic efferent and sensory afferent nerves helps regulate adipocyte size, cell number, lipolysis, and ‘browning’ of white adipose tissue. Neurotrophic factors are growth factors that promote neuron survival, regeneration, and plasticity, including neurite outgrowth and synapse formation. Peripheral immune cells have been shown to be a source of neurotrophic factors in humans and mice. Although a number of immune cells reside in the adipose stromal vascular fraction (SVF), it has remained unclear what roles they play in adipose innervation. We previously demonstrated that adipose SVF secretes brain derived neurotrophic factor (BDNF). Methods We now show that deletion of this neurotrophic factor from the myeloid lineage of immune cells led to a ‘genetic denervation’ of inguinal subcutaneous white adipose tissue (scWAT), thereby causing decreased energy expenditure, increased adipose mass, and a blunted UCP1 response to cold stimulation. Results We and others have previously shown that noradrenergic stimulation via cold exposure increases adipose innervation in the inguinal depot. Here we have identified a subset of myeloid cells that home to scWAT upon cold exposure and are Ly6C+ CCR2+ Cx3CR1+ monocytes/macrophages that express noradrenergic receptors and BDNF. This subset of myeloid lineage cells also clearly interacted with peripheral nerves in the scWAT and were therefore considered neuroimmune cells. Conclusions We propose that these myeloid lineage, cold induced neuroimmune cells (CINCs) are key players in maintaining adipose innervation as well as promoting adipose nerve remodeling under noradrenergic stimulation, such as cold exposure.

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The Role of Autophagy in White Adipose Tissue Function: Implications for Metabolic Health

Metabolites ◽

10.3390/metabo10050179 ◽

2020 ◽

Vol 10 (5) ◽

pp. 179 ◽

Cited By ~ 2

Author(s):

Mercedes Clemente-Postigo ◽

Alberto Tinahones ◽

Rajaa El Bekay ◽

María M. Malagón ◽

Francisco J. Tinahones

Keyword(s):

Adipose Tissue ◽

White Adipose Tissue ◽

Current Data ◽

Metabolic Health ◽

Diabetic Patients ◽

Low Grade ◽

Obesity And Diabetes ◽

Cell Remodeling ◽

Low Grade Inflammation

White adipose tissue (WAT) is a highly adaptive endocrine organ that continuously remodels in response to nutritional cues. WAT expands to store excess energy by increasing adipocyte number and/or size. Failure in WAT expansion has serious consequences on metabolic health resulting in altered lipid, glucose, and inflammatory profiles. Besides an impaired adipogenesis, fibrosis and low-grade inflammation also characterize dysfunctional WAT. Nevertheless, the precise mechanisms leading to impaired WAT expansibility are yet unresolved. Autophagy is a conserved and essential process for cellular homeostasis, which constitutively allows the recycling of damaged or long-lived proteins and organelles, but is also highly induced under stress conditions to provide nutrients and remove pathogens. By modulating protein and organelle content, autophagy is also essential for cell remodeling, maintenance, and survival. In this line, autophagy has been involved in many processes affected during WAT maladaptation, including adipogenesis, adipocyte, and macrophage function, inflammatory response, and fibrosis. WAT autophagy dysregulation is related to obesity and diabetes. However, it remains unclear whether WAT autophagy alteration in obese and diabetic patients are the cause or the consequence of WAT malfunction. In this review, current data regarding these issues are discussed, focusing on evidence from human studies.

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The Involvement of Neuroimmune Cells in Adipose Innervation

10.21203/rs.3.rs-66882/v1 ◽

2020 ◽

Author(s):

Magdalena Blaszkiewicz ◽

Elizabeth Wood ◽

Sigi Koizar ◽

Jake Willows ◽

Ryan Anderson ◽

...

Keyword(s):

Adipose Tissue ◽

White Adipose Tissue ◽

Cold Exposure ◽

Immune Cells ◽

Neurotrophic Factors ◽

Neurotrophic Factor ◽

Stromal Vascular Fraction ◽

Cell Number ◽

Proper Function ◽

Cold Stimulation

Abstract Background: Innervation of adipose tissue is essential for the proper function of this critical metabolic organ. Numerous surgical and chemical denervation studies have demonstrated how maintenance of brain-adipose communication through both sympathetic efferent and sensory afferent nerves helps regulate adipocyte size, cell number, lipolysis, and ‘browning’ of white adipose tissue. Neurotrophic factors are growth factors that promote neuron survival, regeneration and plasticity, including neurite outgrowth and synapse formation. Peripheral blood immune cells have been shown to be a source of neurotrophic factors in humans and mice. Although a number of immune cells reside in the adipose stromal vascular fraction (SVF), it has remained unclear what roles they play in adipose innervation. We previously demonstrated that adipose immune cells secrete brain derived neurotrophic factor (BDNF). Methods: We now show that deletion of this neurotrophic factor from the myeloid lineage led to a ‘genetic denervation’ of inguinal subcutaneous white adipose tissue (scWAT), thereby causing decreased energy expenditure, increased adipose mass, and a blunted UCP1 response to cold stimulation. Results: We and others have previously shown that noradrenergic stimulation via cold exposure increases adipose innervation in the inguinal depot. Here we have identified a subset of myeloid cells that home to scWAT upon cold exposure and are Ly6C + CCR2 + Cx3CR1 + monocytes/macrophages that express noradrenergic receptors and BDNF. Conclusions: We propose that these cold induced neuroimmune cells (CINCs) are key players in maintaining adipose innervation as well as promoting adipose nerve remodeling under noradrenergic stimulation, such as cold exposure.

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The involvement of neuroimmune cells in adipose innervation

10.1101/787234 ◽

2019 ◽

Cited By ~ 1

Author(s):

Magdalena Blaszkiewicz ◽

Elizabeth Wood ◽

Sigi Koizar ◽

Jake Willows ◽

Ryan Anderson ◽

...

Keyword(s):

Adipose Tissue ◽

White Adipose Tissue ◽

Cold Exposure ◽

Immune Cells ◽

Neurotrophic Factors ◽

Neurotrophic Factor ◽

Stromal Vascular Fraction ◽

Cell Number ◽

Proper Function ◽

Cold Stimulation

AbstractBackgroundInnervation of adipose tissue is essential for the proper function of this critical metabolic organ. Numerous surgical and chemical denervation studies have demonstrated how maintenance of brain-adipose communication through both sympathetic efferent and sensory afferent nerves helps regulate adipocyte size, cell number, lipolysis, and ‘browning’ of white adipose tissue. Neurotrophic factors are growth factors that promote neuron survival, regeneration and plasticity, including neurite outgrowth and synapse formation. Peripheral blood immune cells have been shown to be a source of neurotrophic factors in humans and mice. Although a number of immune cells reside in the adipose stromal vascular fraction (SVF), it has remained unclear what roles they play in adipose innervation. We previously demonstrated that adipose immune cells secrete brain derived neurotrophic factor (BDNF).MethodsWe now show that deletion of this neurotrophic factor from the myeloid lineage led to a ‘genetic denervation’ of inguinal subcutaneous white adipose tissue (scWAT), thereby causing decreased energy expenditure, increased adipose mass, and a blunted UCP1 response to cold stimulation.ResultsWe and others have previously shown that noradrenergic stimulation via cold exposure increases adipose innervation in the inguinal depot. Here we have identified a subset of myeloid cells that home to scWAT upon cold exposure and are Ly6C + CCR2 + Cx3CR1 + monocytes/macrophages that express noradrenergic receptors and BDNF.ConclusionsWe propose that these cold induced neuroimmune cells (CINCs) are key players in maintaining adipose innervation as well as promoting adipose nerve remodeling under noradrenergic stimulation, such as cold exposure.

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Emerging Roles for Browning of White Adipose Tissue in Prostate Cancer Malignant Behaviour

International Journal of Molecular Sciences ◽

10.3390/ijms22115560 ◽

2021 ◽

Vol 22 (11) ◽

pp. 5560

Author(s):

Alejandro Álvarez-Artime ◽

Belén García-Soler ◽

Rosa María Sainz ◽

Juan Carlos Mayo

Keyword(s):

Prostate Cancer ◽

Adipose Tissue ◽

White Adipose Tissue ◽

Tumor Development ◽

Cell Types ◽

Protective Role ◽

Bioactive Molecules ◽

Brown Adipose ◽

Endocrine Organs

In addition to its well-known role as an energy repository, adipose tissue is one of the largest endocrine organs in the organism due to its ability to synthesize and release different bioactive molecules. Two main types of adipose tissue have been described, namely white adipose tissue (WAT) with a classical energy storage function, and brown adipose tissue (BAT) with thermogenic activity. The prostate, an exocrine gland present in the reproductive system of most mammals, is surrounded by periprostatic adipose tissue (PPAT) that contributes to maintaining glandular homeostasis in conjunction with other cell types of the microenvironment. In pathological conditions such as the development and progression of prostate cancer, adipose tissue plays a key role through paracrine and endocrine signaling. In this context, the role of WAT has been thoroughly studied. However, the influence of BAT on prostate tumor development and progression is unclear and has received much less attention. This review tries to bring an update on the role of different factors released by WAT which may participate in the initiation, progression and metastasis, as well as to compile the available information on BAT to discuss and open a new field of knowledge about the possible protective role of BAT in prostate cancer.

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Interactive effects of aging and aerobic capacity on energy metabolism–related metabolites of serum, skeletal muscle, and white adipose tissue

GeroScience ◽

10.1007/s11357-021-00387-1 ◽

2021 ◽

Author(s):

Haihui Zhuang ◽

Sira Karvinen ◽

Timo Törmäkangas ◽

Xiaobo Zhang ◽

Xiaowei Ojanen ◽

...

Keyword(s):

Adipose Tissue ◽

Amino Acid ◽

White Adipose Tissue ◽

Aerobic Capacity ◽

Amino Acid Metabolism ◽

Acid Metabolism ◽

Disease Risk ◽

Whole Body ◽

Whole Body Metabolism

AbstractAerobic capacity is a strong predictor of longevity. With aging, aerobic capacity decreases concomitantly with changes in whole body metabolism leading to increased disease risk. To address the role of aerobic capacity, aging, and their interaction on metabolism, we utilized rat models selectively bred for low and high intrinsic aerobic capacity (LCRs/HCRs) and compared the metabolomics of serum, muscle, and white adipose tissue (WAT) at two time points: Young rats were sacrificed at 9 months of age, and old rats were sacrificed at 21 months of age. Targeted and semi-quantitative metabolomics analysis was performed on the ultra-pressure liquid chromatography tandem mass spectrometry (UPLC-MS) platform. The effects of aerobic capacity, aging, and their interaction were studied via regression analysis. Our results showed that high aerobic capacity is associated with an accumulation of isovalerylcarnitine in muscle and serum at rest, which is likely due to more efficient leucine catabolism in muscle. With aging, several amino acids were downregulated in muscle, indicating more efficient amino acid metabolism, whereas in WAT less efficient amino acid metabolism and decreased mitochondrial β-oxidation were observed. Our results further revealed that high aerobic capacity and aging interactively affect lipid metabolism in muscle and WAT, possibly combating unfavorable aging-related changes in whole body metabolism. Our results highlight the significant role of WAT metabolism for healthy aging.

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Front Cover: Nicotinamide Protects Against Diet‐Induced Body Weight Gain, Increases Energy Expenditure, and Induces White Adipose Tissue Beiging

Molecular Nutrition & Food Research ◽

10.1002/mnfr.202170027 ◽

2021 ◽

Vol 65 (11) ◽

pp. 2170027

Author(s):

Karen Alejandra Méndez‐Lara ◽

Elisabeth Rodríguez‐Millán ◽

David Sebastián ◽

Rosi Blanco‐Soto ◽

Mercedes Camacho ◽

...

Keyword(s):

Body Weight ◽

Adipose Tissue ◽

Weight Gain ◽

Energy Expenditure ◽

White Adipose Tissue ◽

Body Weight Gain ◽

Front Cover

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Neonatal nutritional programming impairs adiponectin effects on energy homeostasis in adult life of male rats

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00358.2017 ◽

2018 ◽

Vol 315 (1) ◽

pp. E29-E37 ◽

Cited By ~ 3

Author(s):

Mariana Peduti Halah ◽

Paula Beatriz Marangon ◽

Jose Antunes-Rodrigues ◽

Lucila L. K. Elias

Keyword(s):

Body Weight ◽

Adipose Tissue ◽

Weight Gain ◽

Food Intake ◽

White Adipose Tissue ◽

Energy Homeostasis ◽

Body Weight Gain ◽

Adult Life ◽

Male Rats ◽

Nutritional Programming

Neonatal nutritional changes induce long-lasting effects on energy homeostasis. Adiponectin influences food intake and body weight. The aim of this study was to investigate the effects of neonatal nutritional programming on the central stimulation of adiponectin. Male Wistar rats were divided on postnatal (PN) day 3 in litters of 3 (small litter, SL), 10 (normal litter, NL), or 16 pups/dam (large litter, LL). We assessed body weight gain for 60 days, adiponectin concentration, and white adipose tissue weight. We examined the response of SL, NL, and LL rats on body weight gain, food intake, oxygen consumption (V̇o2), respiratory exchange ratio (RER), calorimetry, locomotor activity, phosphorylated-AMP-activated protein kinase (AMPK) expression in the hypothalamus, and uncoupling protein (UCP)-1 in the brown adipose tissue after central stimulus with adiponectin. After weaning, SL rats maintained higher body weight gain despite similar food intake compared with NL rats. LL rats showed lower body weight at weaning, with a catch up afterward and higher food intake. Both LL and SL groups had decreased plasma concentrations of adiponectin at PN60. SL rats had increased white adipose tissue. Central injection of adiponectin decreased body weight and food intake and increased V̇o2, RER, calorimetry, p-AMPK and UCP- 1 expression in NL rats, but it had no effect on SL and LL rats, compared with the respective vehicle groups. In conclusion, neonatal under- and overfeeding induced an increase in body weight gain in juvenile and early adult life. Unresponsiveness to central effects of adiponectin contributes to the imbalance of the energy homeostasis in adult life induced by neonatal nutritional programming.

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