Perirenal White Adipose Tissue Research Articles

Interactions between glucagon like peptide 1 (GLP-1) and estrogens regulates lipid metabolism

Obesity, characterized by excessive fat accumulation in white adipose tissue (WAT), is linked to numerous health issues, including insulin resistance (IR), and type 2 diabetes mellitus (DM2). The distribution of adipose tissue differs by sex, with men typically exhibiting android adiposity and pre-menopausal women displaying gynecoid adiposity. After menopause, women have an increased risk of developing android-type obesity, IR, and DM2. Glucagon-like peptide 1 (GLP-1) receptor agonists (GLP-1RAs) are important in treating obesity and DM2 by regulating insulin secretion, impacting glucose and lipid metabolism. GLP-1Rs are found in various tissues including the pancreas, brain, and adipose tissue. Studies suggest GLP-1RAs and estrogen replacement therapies have similar effects on tissues like the liver, central nervous system, and WAT, probably by converging pathways involving protein kinasesTo investigate these interactions, female rats underwent ovariectomy (OVR) to promote a state of estrogen deficiency. After 20 days, the rats were euthanized and the tissues were incubated with 10 μM of liraglutide, a GLP-1RA. Results showed significant changes in metabolic parameters: OVR increased lipid catabolism in perirenal WAT and basal lipolysis in subcutaneous WAT, while liraglutide treatment enhanced stimulated lipolysis in subcutaneous WAT. Liver responses included increased stimulated lipolysis with liraglutide. Transcriptome analysis revealed distinct gene expression patterns in WAT of OVR rats and those treated with GLP-1RA, highlighting pathways related to lipid and glucose metabolism. Functional enrichment analysis showed estrogen’s pivotal role in these pathways, influencing genes involved in lipid metabolism regulation.Overall, the study underscores GLP-1RA acting directly on adipose tissues and highlights the complex interactions between GLP-1 and estrogen in regulating metabolism, suggesting potential synergistic therapeutic effects in treating metabolic disorders like obesity and DM2.

The futile creatine cycle and the synthesis of fatty acids in inguinal white adipose tissue from growing rats, submitted to a hypoprotein-hyperglycidic diet for 15 days.

The low-protein, high-carbohydrate (LPHC) diet administered to growing rats soon after weaning, for 15 days, promoted an increase in energy expenditure by uncoupling protein 1 (UCP1) in interscapular brown adipose tissue, and also due to the occurrence of the browning process in the perirenal white adipose tissue (periWAT). However, we believe that inguinal white adipose tissue (ingWAT) may also contribute to energy expenditure through other mechanisms. Therefore, the aim of this work is to investigate the presence of the futile creatine cycle, and the origin of lipids in ingWAT, since that tissue showed an increase in the lipids content in rats submitted to the LPHC diet for 15 days. We observed increases in creatine kinase and alkaline phosphatase activity in ingWAT, of the LPHC animals. The mitochondrial Nicotinamide adenine dinucleotide reduced/nicotinamide adenine dinucleotide oxidized ratio is lower in ingWAT of LPHC animals. In the LPHC animals treated with β-guanidinopropionic acid, the extracellular uptake of creatine in ingWAT was lower, as was the rectal temperature. Regarding lipid metabolism, we observed that in ingWAT, lipolysis in vitro when stimulated with noradrenaline is lower, and there were no changes in baseline levels. In addition, increases in the activity of enzymes were also observed: malic, glucose-6-phosphate dehydrogenase, and ATP-citrate lyase, in addition to an increase in the PPARγ content. The results show the occurrence of the futile creatine cycle in ingWAT, and that the increase in the relative mass may be due to an increase in de novo fatty acid synthesis.

Cellular Evidence for Telocytes Mediating Electroacupuncture to Ameliorate Obesity in Mice.

Electroacupuncture has been generally applied to target obesity, the principle of which is based on the meridian in traditional Chinese medicine. Although Telocytes (TCs) have been reported as the potential essence of meridians, their specific role in the electroacupuncture treatment of obesity remains unclear. Thus, we investigated the cellular evidence for TC-mediated electroacupuncture to alleviate obesity. Mice were divided into three groups as follows: electroacupuncture group (EA), control group (CG), and normal group (NG). The present study showed that the weight of perirenal white adipose tissue (rWAT), the serum level of total cholesterol, and the low-density lipoprotein cholesterol were all significantly decreased after electroacupuncture. Ultrastructurally, the prolongations (telopodes, Tps) of TCs were in direct contact with adipocytes, and lipid droplets were distributed on the surface of Tps. The proportions of double-positive fluorescent areas of TCs (CD34 and PDGFRα) were significantly elevated with concomitant elongated Tps in EA mice, as compared to those in CG mice. The expression of Cx43 and CD63 (gap junction and exosome markers) was significantly enhanced. These characteristics facilitated the transmission of electroacupuncture stimulation from skin to rWAT. We conclude that electroacupuncture relieved obesity by activating TCs morphologically, upregulating the gap junctions between TCs, and increasing the exosomes around TCs.

Electroacupuncture improves obesity and promotes white adipose tissue browning by regulating central glucagon-like peptide-1

To observe the effect of electroacupuncture （EA） on white adipose tissue （WAT） browning by regulating central glucagon-like peptide-1 （GLP-1）, so as to explore the possible central mechanisms of EA in improving obesity. Thirty male Wistar rats were randomly divided into normal group, model group, EA group, HM3D group, and EA+HM4D group, with 6 rats in each group. The obesity rat model was obtained by feeding with high-fat diet for 8 weeks. Adeno-associated virus combined with DREADDs was injected into bilateral nucleus of solitary tract （NTS）, with rAAV-GLP-1+rAAV-4D applied to the EA+HM4D group, rAAV-GLP-1+rAAV-3D applied to the HM3D group, and rAAV-GLP-1+rAAV-GFP applied to other 3 groups. After modeling, rats in the EA and EA+HM4D groups received EA treatment at bilateral "Zusanli"（ST36）, "Fenglong"（ST40）, "Guanyuan"（CV4） and "Zhongwan"（CV12）, with successive waves （2 Hz, 1 mA） for 10 minutes, 3 times a week, for a total of 8 weeks. Body mass of rats in each group were measured before and 2, 4, 6, and 8 weeks after intervention. Abdominal and perirenal WAT mass was weighed, serum triglyceride （TG） and total cholesterol （TC） contents were detected by using automatic analyzer, and nonestesterified fatty acid （NEFA） content was detected by using colorimetric assay kit. The morphology of abdominal WAT lipid droplets was observed by HE staining. The mRNA expressions of GLP-1 in NTS, AMPK in ventromedial nucleus of hypothalamus（VMH）, UCP1 and PGC-1α in subcutaneous fat were detected by real-time PCR. The protein expression levels of GLP-1, AMPK, phosphorylated-AMPK, UCP1 and PGC-1α were detected by Western blot. The activation level of GLP-1 neurons in NTS was observed by immunofluorescence. Compared with the normal group, abdominal WAT lipid droplets were enlarged, body weight, serum TG, TC, NEFA contents, abdominal and perirenal WAT mass, mRNA and protein expression levels of AMPK were significantly increased（P<0.01, P<0.05）, while GLP-1 neurons activation level, mRNA and protein expression levels of GLP-1, UCP1 and PGC-1α, and AMPK protein phosphorylation were decreased （P<0.01） in the model group. After EA intervention, body weight at 6 and 8 weeks after intervention and other indexes mentioned above were all significantly reversed （P<0.01, P<0.05） in the EA group in comparison with those of the model group. Compared with the EA group, the HM3D group had reduced abdominal WAT lipid droplets size, decreased serum TG, TC, and NEFA contents, and protein expression level of AMPK（P<0.01, P<0.05）, with increased mRNA and protein expression levels of GLP-1, UCP1 and PGC-1α, and phosphorylation level of AMPK protein（P<0.01, P<0.05）, while the EA+HM4D group had enlarged abdominal WAT lipid droplets, increased body weight 6 and 8 weeks after intervention, abdominal and renal WAT mass, and NEFA content （P<0.01, P<0.05）, with decreased serum TG content, activation level of GLP-1 neurons in the NTS, mRNA and protein expression levels of GLP-1, UCP1 and PGC-1α （P<0.01, P<0.05）, as well as down-regulated phosphorylation of AMPK protein and mRNA （P<0.01, P<0.05）. EA can effectively promote the browning of WAT, which may be related to the activation of GLP-1 neurons in the NTS, as well as the promotion of the phosphorylation of AMPK in the VMH and up-regulation of UCP1.

Electroacupuncture improves obesity and promotes white adipose tissue browning by regulating central glucagon-like peptide-1

To observe the effect of electroacupuncture （EA） on white adipose tissue （WAT） browning by regulating central glucagon-like peptide-1 （GLP-1）, so as to explore the possible central mechanisms of EA in improving obesity. Thirty male Wistar rats were randomly divided into normal group, model group, EA group, HM3D group, and EA+HM4D group, with 6 rats in each group. The obesity rat model was obtained by feeding with high-fat diet for 8 weeks. Adeno-associated virus combined with DREADDs was injected into bilateral nucleus of solitary tract （NTS）, with rAAV-GLP-1+rAAV-4D applied to the EA+HM4D group, rAAV-GLP-1+rAAV-3D applied to the HM3D group, and rAAV-GLP-1+rAAV-GFP applied to other 3 groups. After modeling, rats in the EA and EA+HM4D groups received EA treatment at bilateral "Zusanli"（ST36）, "Fenglong"（ST40）, "Guanyuan"（CV4） and "Zhongwan"（CV12）, with successive waves （2 Hz, 1 mA） for 10 minutes, 3 times a week, for a total of 8 weeks. Body mass of rats in each group were measured before and 2, 4, 6, and 8 weeks after intervention. Abdominal and perirenal WAT mass was weighed, serum triglyceride （TG） and total cholesterol （TC） contents were detected by using automatic analyzer, and nonestesterified fatty acid （NEFA） content was detected by using colorimetric assay kit. The morphology of abdominal WAT lipid droplets was observed by HE staining. The mRNA expressions of GLP-1 in NTS, AMPK in ventromedial nucleus of hypothalamus（VMH）, UCP1 and PGC-1α in subcutaneous fat were detected by real-time PCR. The protein expression levels of GLP-1, AMPK, phosphorylated-AMPK, UCP1 and PGC-1α were detected by Western blot. The activation level of GLP-1 neurons in NTS was observed by immunofluorescence. Compared with the normal group, abdominal WAT lipid droplets were enlarged, body weight, serum TG, TC, NEFA contents, abdominal and perirenal WAT mass, mRNA and protein expression levels of AMPK were significantly increased（P<0.01, P<0.05）, while GLP-1 neurons activation level, mRNA and protein expression levels of GLP-1, UCP1 and PGC-1α, and AMPK protein phosphorylation were decreased （P<0.01） in the model group. After EA intervention, body weight at 6 and 8 weeks after intervention and other indexes mentioned above were all significantly reversed （P<0.01, P<0.05） in the EA group in comparison with those of the model group. Compared with the EA group, the HM3D group had reduced abdominal WAT lipid droplets size, decreased serum TG, TC, and NEFA contents, and protein expression level of AMPK（P<0.01, P<0.05）, with increased mRNA and protein expression levels of GLP-1, UCP1 and PGC-1α, and phosphorylation level of AMPK protein（P<0.01, P<0.05）, while the EA+HM4D group had enlarged abdominal WAT lipid droplets, increased body weight 6 and 8 weeks after intervention, abdominal and renal WAT mass, and NEFA content （P<0.01, P<0.05）, with decreased serum TG content, activation level of GLP-1 neurons in the NTS, mRNA and protein expression levels of GLP-1, UCP1 and PGC-1α （P<0.01, P<0.05）, as well as down-regulated phosphorylation of AMPK protein and mRNA （P<0.01, P<0.05）. EA can effectively promote the browning of WAT, which may be related to the activation of GLP-1 neurons in the NTS, as well as the promotion of the phosphorylation of AMPK in the VMH and up-regulation of UCP1.

Neonatal hyperoxia leads to white adipose tissue remodeling and susceptibility to hypercaloric diet

AbstractIndividuals born preterm are at higher risk of cardiovascular and metabolic diseases in adulthood, through mechanisms not completely understood. White adipose tissue in humans and rodents is a dynamic endocrine organ and a critical player in the regulation of metabolic homeostasis. However, the impact of preterm birth on white adipose tissue remains unknown. Using a well‐established rodent model of preterm birth‐related conditions in which newborn rats are exposed during postnatal days 3–10 to 80% of oxygen, we evaluated the impact of transient neonatal hyperoxia on adult perirenal white adipose tissue (pWAT) and liver. We further assessed the effect of a second hit with a high‐fat high‐fructose hypercaloric diet (HFFD). We evaluated 4‐month‐old adult male rats after 2 months of HFFD. Neonatal hyperoxia led to pWAT fibrosis and macrophage infiltration without modification in body weight, pWAT weight, or adipocyte size. In animals exposed to neonatal hyperoxia vs. room air control, HFFD resulted in adipocyte hypertrophy, lipid accumulation in the liver, and increased circulating triglycerides. Overall, preterm birth‐related conditions had long‐lasting effects on the composition and morphology of pWAT, along with a higher susceptibility to the deleterious impact of a hypercaloric diet. These changes suggest a developmental pathway to long‐term metabolic risk factors observed clinically in adults born preterm through programming of white adipose tissue.

Effects and action mechanisms of lotus leaf (Nelumbo nucifera) ethanol extract on gut microbes and obesity in high-fat diet-fed rats.

The present study aimed to clarify the effect of the lotus leaf ethanol extract (LLEE) on the mechanism of antiobesity and the intestinal microbiota of obese rats. A total of 40 specific pathogen-free (SPF) male Sprague-Dawley (SD) rats were split into the blank control group, the model control group, the Orlistat capsule control group, and the LLEE group. All the groups were intervened and fed specific diets for 5 months. During the experiment, we evaluated the rats' body weight, length, serum biochemical indicators, and inflammatory factor levels. After dissection, the liver; epididymal and perirenal white adipose tissue (WAT); and the contents of the cecum were collected for pathological evaluation and intestinal flora analysis. Lotus leaf alcohol extract can significantly reduce the serum total cholesterol, triglyceride, and low-density lipoprotein cholesterol levels. It also decreases the accumulation of fatty deposits in the liver of rats and the levels of serum inflammatory factors IL-6 and TNF-α and increases the level of IL-10. Lotus leaf alcohol extracts significantly increased the abundance of Muribaculaceae in the intestinal flora of rats, reduced the abundance of pro-inflammatory bacteria Firmicutes, and relieved fatty liver and other inflammation and diseases caused by a high-fat diet. Besides, the ethanol extract of the lotus leaf significantly regulated the abundance of Ruminococcus, suggesting that the ethanol extract of the lotus leaf may prevent hyperlipidemia. We elucidated the effects and action mechanisms of LLEE on obesity in high-fat diet-fed rats to provide suggestions for regulating intestinal flora through dietary intervention and thus improving blood lipid metabolism.

Hypoxia promotes white adipose tissues browning in rats under simulated environment at altitude of 5000 m

People living in plains tend to decrease in body weight or body fat percentage after entering the plateau. Previous studies have found that plateau animals can burn fat and release calories through white adipose tissues (WATs) browning. However, these studies have focused on the effect of cold stimulation that induced WATs browning while there's hardly study on the effect of hypoxia. In this study, we investigate that whether and how hypoxia contributes to WATs browning in rats from acute to chronic hypoxia. We constructed hypobaric hypoxic rat models by exposing 9-week-old male SD rats to a hypobaric hypoxic chamber for 1, 3, 14 and 28 days (Group H) under simulated environment at altitude of 5000 m. We also established normoxic control groups for each time period (Group C), as well as paired 1-day and 14-day normoxic food-restriction rats that were fed the same amount of food as the hypoxic group ate (Group R). We then observed the growth status of rats and recorded dynamic changes in histologic, cellular and molecular levels of perirenal WATs (PWAT), epididymal WATs (EWAT) and subcutaneous WATs (SWAT) in each group. Results showed that (1) Hypoxic rats had lower food intake, significantly lower body weight than control rats, and showed lower WATs index. (2) In group H14, ASC1 mRNA expressions of PWAT and EWAT in rats were lower than that in group C14, and PAT2 mRNA expression of EWAT was higher than that in both group C14 and R14. In group R14, however, ASC1 mRNA expressions of PWAT and EWAT in rats were higher than both group C14 and H14, and that of SWAT was also significantly higher than group C14. (3) In group H3, both the mRNA and protein levels of uncoupling protein 1 (UCP1) of PWAT in rats were significantly increased than group C3. And in group H14, those of EWAT in rats were significantly increased than group C14. (4) In plasma of rats, norepinephrine (NE) level was significantly increased in group H3 than group C3, and free fatty acids (FFAs) level was significantly increased in group H14 than both group C14 and R14. In group R1, FASN mRNA expressions of PWAT and EWAT in rats were down-regulated than group C1. In group H3, FASN mRNA expressions of PWAT and EWAT in rats were down-regulated while ATGL mRNA expression of EWAT was up-regulated than group C3. Conversely, in group R14, FASN mRNA expressions of PWAT and EWAT in rats were significantly up-regulated than group C14 and H14. These results suggested that hypoxia promoted different WATs browning in rats under simulated environment at altitude of 5000 m and changed the lipid metabolism in WATs. Furthermore, rats in the chronic hypoxic group showed a completely different lipid metabolism of WATs from that in paired food-restriction group.

4-PBA inhibits hypoxia-induced lipolysis in rat adipose tissue and lipid accumulation in the liver through regulating ER stress.

High-altitude hypoxia may disturb the metabolic modulation and function of both adipose tissue and liver. The endoplasmic reticulum (ER) is a crucial organelle in lipid metabolism and ER stress is closely correlated with lipid metabolism dysfunction. The aim of this study is to elucidate whether the inhibition of ER stress could alleviate hypoxia-induced white adipose tissue (WAT) lipolysis and liver lipid accumulation-mediated hepatic injury. A rat model of high-altitude hypoxia (5500 m) was established using hypobaric chamber. The response of ER stress and lipolysis-related pathways were analyzed in WAT under hypoxia exposure with or without 4-phenylbutyric acid (PBA) treatment. Liver lipid accumulation, liver injury, and apoptosis were evaluated. Hypoxia evoked significant ER stress in WAT, evidenced by increased GRP78, CHOP, and phosphorylation of IRE1α, PERK. Moreover, Lipolysis in perirenal WAT significantly increased under hypoxia, accompanied with increased phosphorylation of hormone-sensitive lipase (HSL) and perilipin. Treatment with 4-PBA, inhibitor of ER stress, effectively attenuated hypoxia-induced lipolysis via cAMP-PKA-HSL/perilipin pathway. In addition, 4-PBA treatment significantly inhibited the increase in fatty acid transporters (CD36, FABP1, FABP4) and ameliorated liver FFA accumulation. 4-PBA treatment significantly attenuated liver injury and apoptosis, which is likely resulting from decreased liver lipid accumulation. Our results highlight the importance of ER stress in hypoxia-induced WAT lipolysis and liver lipid accumulation.

High-starchy carbohydrate diet aggravates NAFLD by increasing fatty acids influx mediated by NOX2

Nonalcoholic fatty liver disease (NAFLD) is a high-incidence lipid disorder that affects more than a quarter of the population worldwide, and dietary intervention is the recognized treatment. Starch is the main component of staple foods that are consumed daily, and the effects, metabolic pathway, and molecular mechanism of starch in the context of NAFLD remain unclear. Our study showed that a high-starch carbohydrate diet (HCD) led to the occurrence and exacerbation of NAFLD in mice. Transcriptomics and metabonomic analyses showed that the increased fatty acid influx mediated by NADPH oxidase 2 (NOX2) exacerbated NAFLD. Knocking down NOX2 specifically alleviated HCD-induced NAFLD in vivo and in vitro. Moreover, the large amounts of ROS produced by NOX2 further exacerbated insulin resistance and increased lipolysis in perirenal white adipose tissue (periWAT), thereby providing fatty acids for hepatic lipid synthesis. In addition, the interaction between AMPKα1 and p47phox was the pathway that mediated the high expression of NOX2 induced by a HCD. Our study systematically demonstrated the effect of a HCD on NAFLD. Elevated fatty acid influx is a unique molecular regulatory pathway that mediates HCD-induced NAFLD exacerbation, which is different from the effect of simple sugars. Additionally, NOX2 was suggested to be a specific and effective drug target for NAFLD.

Relationships between rumen microbes, short-chain fatty acids, and markers of white adipose tissue browning during the cold season in grazing Mongolian sheep (Ovisaries)

Mongolian sheep are characteristically cold-tolerant and they partially depend on seasonal browning of white adipose tissue (WAT) to acclimate to cold environments. The present work aimed to examine the rumen microbes, rumen fermentation profile, and relationships between the rumen microbiota, short-chain fatty acids (SCFAs), and markers of WAT browning and are thus conducive to exploring the plateau environment adaptability of Mongolian sheep in the cold season. A comparative analysis of the rumen microbes and SCFAs in the cold and warm seasons was conducted. Rumen microbes were analyzed using Illumina sequencing of the 16S rRNA gene. Ruminal SCFAs were determined by gas chromatography. Spearman's correlation test was used to determine the relationships between the rumen microbiota, SCFAs, and markers of WAT browning. Microbial 16S rRNA sequencing revealed a marked shift in rumen microbiota composition between the two seasons, and the bacteria were characterized by increased levels of the Actinobacteria and genera Christensenellaceae R-7 group, Ruminococcaceae UCG-011, Rikenellaceae RC9 gut group, Papillibacter, and Butyrivibrio 2 and reduced levels of Prevotella 1 and Ruminococcaceae UCG-014 in the cold season (P<0.05). Furthermore, the concentrations of SCFAs such as acetate and butyrate were significantly increased in the cold season (P<0.001 and P<0.05, respectively). Correlation analysis demonstrated that the relative abundances of the Actinobacteria and the genera Christensenellaceae R-7 group, Butyrivibrio 2, Ruminococcaceae UCG-002, and Ruminococcaceae UCG-011, identified as members of the Christensenellaceae, Lachnospiraceae, and Ruminococcaceae families (all within Firmicutes), were positively correlated with markers of browning in either retroperitoneal WAT or perirenal WAT, and acetate was positively correlated with Ruminococcaceae UCG-011 and Butyrivibrio 2 and markers of browning in either retroperitoneal WAT or perirenal WAT. Overall, there are distinct relationships between the rumen microbiota, ruminal SCFAs and markers of WAT browning during the cold season in grazing Mongolian sheep.

Role of white adipose tissue browning in cold seasonal acclimation in grazing Mongolian sheep (Ovisaries)

Mongolian sheep are characteristically cold-tolerant and thus can survive well and maintain genetic stability in the extremely cold environment of the Mongolian Plateau. However, the adaptive mechanism of Mongolian sheep during the cold season in the plateau environment remains unknown. Browning of white adipose tissues (WAT) can trigger nonshivering thermogenesis as a potential strategy to promote an animal's tolerance to cold environments. Thus, a comparative analysis of the genes and proteins of uncoupling protein 1 (UCP1)-dependent and UCP1-independent browning pathways, mitochondrial biogenesis, lipogenic and lipolytic processes of WAT from grazing Mongolian sheep in the cold and warm seasons was conducted. We found seasonal browning of both retroperitoneal WAT and perirenal WAT, and the signalling of the process was mainly transduced by the UCP1- dependent pathway, primarily reflected in the upregulated gene levels of UCP1 and peroxisome proliferative activated receptor gamma coactivator 1 alpha (PGC-1α). In addition, the mean adipocyte diameter and mRNA expression of lipogenic genes in both interscapular WAT and subcutaneous WAT were significantly elevated during the cold season. The findings of this study demonstrate that grazing Mongolian sheep could depend on seasonal browning of both retroperitoneal WAT and perirenal WAT together with the expansion of both interscapular WAT and subcutaneous WAT to acclimate to cold environments of the Mongolian Plateau.

Renal peritumoral adipose tissue undergoes a browning process and stimulates the expression of epithelial-mesenchymal transition markers in human renal cells

Tumor cells can interact with neighboring adipose cells and adipocyte dedifferentiation appears to be an important aspect of tumorigenesis. We evaluated the size of adipocytes in human adipose explants from normal (hRAN) and kidney cancer (hRAT); changes in the expression of WAT and BAT/beige markers in hRAN and hRAT; the expression of epithelial-mesenchymal transition (EMT) cell markers in human kidney tumor (786-O, ACHN and Caki-1); and non-tumor (HK-2) epithelial cell lines incubated with the conditioned media (CMs) of hRAN and hRAT. We observed that hRAT adipocytes showed a significantly minor size compared to hRAN adipocytes. Also, we observed that both Prdm16 and Tbx1 mRNA and the expression of UCP1, TBX1, PPARγ, PCG1α, c/EBPα LAP and c/EBPα LIP was significantly higher in hRAT than hRAN. Finally, we found an increase in vimentin and N-cadherin expression in HK-2 cells incubated for 24 h with hRAT-CMs compared to hRAN- and control-CMs. Furthermore, desmin and N-cadherin expression also increased significantly in 786-O when these cells were incubated with hRAT-CMs compared to the value observed with hRAN- and control-CMs. We observed a significant decrease in E-cadherin expression in the ACHN cell line incubated with hRAT-CMs versus hRAN- and control-CMs. However, we did not observe changes in E-cadherin expression in HK-2, 786-O or Caki-1. The results obtained, together with the results previously published by our group, allow us to conclude that perirenal white adipose tissue browning contributes to tumor development in kidney cancer. In addition, hRAT-CMs increases the expression of mesenchymal markers in renal epithelial cells, which could indicate a regulation of EMT due to this adipose tissue.

Cardiovascular Characteristics of Zucker Fatty Diabetes Mellitus Rats, an Animal Model for Obesity and Type 2 Diabetes.

Zucker fatty diabetes mellitus (ZFDM) rats harboring the missense mutation (fa) in a leptin receptor gene have been recently established as a novel animal model of obesity and type 2 diabetes (T2D). Here, we explored changes in cardiovascular dynamics including blood pressure and heart rate (HR) associated with the progression of obesity and T2D, as well as pathological changes in adipose tissue and kidney. There was no significant difference in systolic blood pressure (SBP) in ZFDM-Leprfa/fa (Homo) compared with ZFDM-Leprfa/+ (Hetero) rats, while HR and plasma adrenaline in Homo were significantly lower than Hetero. The mRNA expression of monocyte chemotactic protein-1 in perirenal white adipose tissue (WAT) from Homo was significantly higher than Hetero. Interscapular brown adipose tissue (BAT) in Homo was degenerated and whitened. The plasma blood urea nitrogen in Homo was significantly higher than Hetero. In summary, we demonstrated for the first time that HR and plasma adrenaline concentration but not SBP in Homo decrease with obesity and T2D. In addition, inflammation occurs in WAT from Homo, while whitening occurs in BAT. Further, renal function is impaired in Homo. In the future, ZFDM rats will be useful for investigating metabolic changes associated with the progression of obesity and T2D.

Lactobacillus casei Zhang exerts anti-obesity effect to obese glut1 and gut-specific-glut1 knockout mice via gut microbiota modulation mediated different metagenomic pathways.

Obesity is a major risk factor for various metabolic diseases, including metabolic syndrome and type-2 diabetes. Glucose transporter 1 (GLUT1) impairment has been proposed as a mechanism of fat accumulation and glucose tolerance. Our aims were to determine the role of intestinal epithelial glut1 activity in obesity and the mechanism of anti-obesity effect of Lactobacillus casei Zhang (LCZ) intervention in the absence of gut villi-specific glut1 expression. This study compared the body weight, intestinal microbiota perturbations, fat mass accumulation, and glucose tolerance (by oral glucose tolerance test) between high-fat diet fed villi-specific glut1 knockout (KO) mice and control mice (glut1 flox/flox) with/without LCZ intervention. The intestinal microbiota was evaluated by metagenomic sequencing. Our results showed that villi-specific glut1 KO mice had more fat deposition at the premetaphase stage, impaired glucose tolerance, and obvious alterations in gut microbiota compared to control mice. Probiotic administration significantly lowered the body weight, the weights of mesenteric and perirenal white adipose tissues (WAT), and mediated gut microbiota modulation in both types of KO and control mice. The species Barnesiella intestinihominis and Faecalibaculum rodentium might contribute to fasting fat mass accumulation associated with gut-specific glut1 inactivation, while the probiotic-mediated anti-obesity effect was linked to members of the Bacteroides genera, Odoribacter genera and Alistipes finegoldii. Our study demonstrated that abrogating gut epithelial GLUT1 activity affected the gut microbiota, fat mass accumulation, and glucose tolerance; and LCZ administration reduced fat mass accumulation and central obesity.

Empagliflozin Induces White Adipocyte Browning and Modulates Mitochondrial Dynamics in KK Cg-Ay/J Mice and Mouse Adipocytes.

Background: White adipose tissue (WAT) browning is a promising target for obesity prevention and treatment. Empagliflozin has emerged as an agent with weight-loss potential in clinical and in vivo studies, but the mechanisms underlying its effect are not fully understood. Here, we investigated whether empagliflozin could induce WAT browning and mitochondrial alterations in KK Cg-Ay/J (KKAy) mice, and explored the mechanisms of its effects.Methods: Eight-week-old male KKAy mice were administered empagliflozin or saline for 8 weeks and compared with control C57BL/6J mice. Mature 3T3-L1 adipocytes were treated in the presence or absence of empagliflozin. Mitochondrial biosynthesis, dynamics, and function were evaluated by gene expression analyses, fluorescence microscopy, and enzymatic assays. The roles of adenosine monophosphate–activated protein kinase (AMPK) and peroxisome proliferator–activated receptor-γ coactivator-1-alpha (PGC-1α) were determined through AICAR (5-Aminoimidazole-4-carboxamide1-β-D-ribofuranoside)/Compound C and RNA interference, respectively.Results: Empagliflozin substantially reduced the bodyweight of KKAy mice. Mice treated with empagliflozin exhibited elevated cold-induced thermogenesis and higher expression levels of uncoupling protein 1 (UCP1) and other brown adipose tissue signature proteins in epididymal and perirenal WAT, which was an indication of browning in these WAT depots. At the same time, empagliflozin enhanced fusion protein mitofusin 2 (MFN2) expression, while decreasing the levels of the fission marker phosphorylated dynamin-related protein 1 (Ser616) [p-DRP1 (Ser616)] in epididymal and perirenal WAT. Empagliflozin also increased mitochondrial biogenesis and fusion, improved mitochondrial integrity and function, and promoted browning of 3T3-L1 adipocytes. Further, we found that AMPK signaling activity played an indispensable role in empagliflozin-induced browning and mitochondrial biogenesis, and that PGC-1α was required for empagliflozin-induced fusion. Whether empagliflozin activates AMPK by inhibition of SGLT2 or by independent mechanisms remains to be tested.Conclusion: Our results suggest that empagliflozin is a promising anti-obesity treatment, which can immediately induce WAT browning mitochondrial biogenesis, and regulate mitochondrial dynamics.

Overexpression of the Gene Encoding Neurosecretory Protein GL Precursor Prevents Excessive Fat Accumulation in the Adipose Tissue of Mice Fed a Long-Term High-Fat Diet.

We previously identified a novel small hypothalamic protein, neurosecretory protein GL (NPGL), which induces feeding behavior and fat accumulation in rodents depending on their diet. In the present study, we explored the effects of NPGL on feeding behavior and energy metabolism in mice placed on a long-term high-fat diet with 60% calories from fat (HFD 60). Overexpression of the NPGL precursor gene (Npgl) over 18 weeks increased food intake and weight. The weekly weight gain of Npgl-overexpressing mice was higher than that of controls until 7 weeks from induction of overexpression, after which it ceased to be so. Oral glucose tolerance tests showed that Npgl overexpression maintained glucose tolerance and increased blood insulin levels, and intraperitoneal insulin tolerance tests showed that it maintained insulin sensitivity. At the experimental endpoint, Npgl overexpression was associated with increased mass of the perirenal white adipose tissue (WAT) and decreased mass of the epididymal WAT (eWAT), resulting in little effect on the total WAT mass. These results suggest that under long-term HFD 60 feeding, Npgl overexpression may play a role in avoiding metabolic disturbance both by accelerating energy storage and by suppressing excess fat accumulation in certain tissues, such as the eWAT.

Cardiometabolic Phenotypic Differences in Male Offspring Born to Obese Preeclamptic-Like BPH/5 Mice

Preeclampsia (PE) is a hypertensive disorder of pregnancy occurring in approximately 10% of women worldwide. While it is life threatening to both the mother and baby, the only effective treatment is delivery of the placenta and fetus, which is often preterm. Maternal obesity is a risk factor for PE, and the effects of both on offspring are long standing with increased incidence of cardiometabolic disease in adulthood. Obese BPH/5 mice spontaneously exhibit excessive gestational weight gain and late-gestational hypertension, similar to women with PE, along with fetal growth restriction and accelerated compensatory growth in female offspring. We hypothesized that BPH/5 male offspring will demonstrate cardiovascular and metabolic phenotypes similar to BPH/5 females. As previously described, BPH/5 females born to ad libitum-fed dams are overweight with hyperphagia and increased subcutaneous, peri-renal, and peri-gonadal white adipose tissue (WAT) and cardiomegaly compared to age-matched adult female controls. In this study, BPH/5 adult male mice have similar body weights and food intake compared to age-matched control mice but have increased inflammatory subcutaneous and peri-renal WAT and signs of cardiovascular disease: left ventricular hypertrophy and hypertension. Therefore, adult male BPH/5 do not completely phenocopy the cardiometabolic profile of female BPH/5 mice. Future investigations are necessary to understand the differences observed in BPH/5 male and female mice as they age. In conclusion, the impact of fetal programming due to PE has a transgenerational effect on both male and female offspring in the BPH/5 mouse model. The maternal obesogenic environment may play a role in PE pregnancy outcomes, including offspring health as they age.

Abstract P230: Prevention Of Maternal Obesity Attenuates Adverse Offspring Cardiometabolic Outcomes In Preeclamptic-like Mouse Model

Preeclampsia (PE) is a hypertensive disorder of pregnancy and a leading cause of maternal and fetal mortality with maternal obesity as a risk factor. Decreasing white adipose tissue (WAT) via calorie restriction during the first half of pregnancy may alter the maternal-fetal environment to improve offspring outcomes. We hypothesized that pair-feeding BPH/5 dams during pregnancy will improve cardiometabolic risk and WAT pro-inflammatory cytokine expression in BPH/5 offspring in a sex-dependent manner. Previously, we showed that BPH/5 males, unlike females, have similar body weights, daily food intake, and circulating leptin levels as compared to age-matched control mice. Although, adult BPH/5 females and males have cardiomegaly and increased subcutaneous and peri-renal WAT mass compared to lean control mice. To investigate the prevention of maternal obesity on offspring outcomes, BPH/5 dams were pair-fed (PF) beginning at embryonic day (e)0.5 to C57 pregnant mice. Offspring cardiometabolic risk and WAT pro-inflammatory cytokine mRNA were measured using real time PCR in adult ad libitum fed offspring. Compared to controls, peri-renal WAT from BPH/5 males showed a 5-fold increase while females had a 15-fold increase in TNFa (n=3-6; p&lt;0.05), 6-fold increase in PTGS-2 for males and 5-fold increase for females (n=3-6; p&lt;0.05), and 3-fold increase in IL-6 for males and 1.25-fold increase for females (n=3-6; p&lt;0.05) in subcutaneous WAT. Adult offspring born to PF BPH/5 dams had decreased expression in TNFa (male: 4-fold and female: 7-fold), PTGS-2 (male: 5-fold and female: 4-fold), and IL-6 (male: 10-fold; n=3-6; p&lt;0.05). In conclusion, prevention of maternal obesity in BPH/5 dams attenuates cardiometabolic risks and reduces the pro-inflammatory WAT milieu in male and female offspring. The transgenerational effects during pregnancy is believed to be caused by an alteration in the maternal-fetal environment due to WAT pro-inflammatory adipokines. Future investigations are necessary to understand the differences observed in BPH/5 male versus female mice into adulthood as well as the transgenerational impact of attenuated maternal obesity in pregnancy.

Abstract 60: Perirenal Adipose Hypertrophy In A Congenic LH Rat: A Role For C17h6orf52

Central obesity, high blood pressure, dyslipidemia, and insulin resistance are a collection of cardiovascular and metabolic risk factors that form the basis of the Metabolic Syndrome (MetS) and represent a major public health burden worldwide. The phenotypes that define MetS are all highly heritable, but their genetic complexity necessitates the use of animal models to tease apart novel pathways. The Lyon Hypertensive (LH) rat is a well-characterized model of MetS, exhibiting profound differences in features of MetS compared to its metabolically healthy control, the Lyon Normotensive (LN) rat. To understand the genomic causes of MetS, we developed a congenic rat model, where a portion of LN chromosome 17 is introgressed on the LH genomic background. Male and female LH congenic (CON) rats and LH controls were phenotyped for a variety of MetS characteristics, including body growth and composition by nuclear magnetic resonance (NMR), metabolic rate (Promethion system), and adipose tissue collection and histological examination. There were significant decreases in body weight in the CON rats of both sexes compared to LH. We also found significant female-specific increases in body fat and decreases in metabolic rate. Tissue collection revealed the source of the increased adiposity in the female CON rats was specific to perirenal white adipose tissue (PWAT) and was further explained by significant hypertrophy in those adipocytes. Genome resequencing of the parental strains identified a gene, C17h6orf52 , as a strong contender underlying the phenotype differences in the congenics, with predicted amino acid changes and the loss of Nr2f2 transcription factor binding sites.