Mesenteric Adipose Research Articles

Prenatal alcohol alters inflammatory signatures in enteric portal tissues following adult-onset cerebrovascular ischemic stroke

Prenatal alcohol exposure (PAE) impairs recovery from cerebrovascular ischemic stroke in adult rodents. Since the gut becomes dysbiotic following stroke, we assessed links between PAE and enteric portal inflammation. Adult control and PAE rat offspring received a unilateral endothelin-1-induced occlusion of the middle cerebral artery. Post-stroke behavioral disabilities and brain cytokines were assessed. Mesenteric adipose and liver transcriptomes were assessed from stroke-exposed and stroke-naive offspring. We identified, in the liver of stroke-naive animals, a moderate correlation between PAE and a gene network for inflammatory necroptosis. PAE inhibited the acute-phase brain inflammatory cytokine response to stroke. Post-stroke neurological function was correlated with an adipose gene network associated with B-lymphocyte differentiation and nuclear factor κB (NF-κB) signaling and with a liver pro-inflammatory gene network. Collectively, PAE inhibits brain inflammation but results in an inflammatory signature in enteric portal tissues after stroke, suggesting that PAE persistently and adversely impacts the gut-brain axis following adult-onset disease.

Improvements of Solubility and Bioavailability of Lutein Through Grafting with Hydrophilic Polyacrylic Acid

In this study, polyacrylic acid grafted lutein (PAA-g-lutein) was prepared by hydrophilic modification of lutein with polyacrylic acid (PAA) through Steglish esterification method. The unreacted lutein was loaded in micelles formed by self-assembly of graft copolymers in water to form composite nanoparticles. The bioaccessibility and bioavailability of lutein nanoparticles were studied by in vitro and in vivo digestion experiments. Compared with free lutein, the saturated solubility and bioaccessibility of lutein nanoparticles were increased by 78 times and 3.6 times, respectively. The pharmacokinetics results in the mice model showed that the maximum concentration (Cmax) and area under concentration-time curve (AUC) of plasma of mice were increased by 3.05 and 6.07 times with lutein nanoparticles compared with free lutein. Meanwhile, the prepared lutein nanoparticles also promoted the accumulation of lutein in the liver, mesenteric adipose, and eyeballs. These results indicate that graft copolymerization of lutein with water-soluble polymers to form nanoparticles is an effective method to promote the bioavailability of lutein in vivo. Moreover, this method is simple and applicable, and can also be used for the modification of other bioactive molecules.

Abstract WP241: Transcriptome Analysis Of The Liver Reveals Novel Mechanisms By Which Prenatal Alcohol Exposure Contributes To Worse Stoke Outcome

Introduction: Susceptibility to adult-onset disease has been linked to early life adversity. In this study, we assessed the impact of a common early adverse experience, prenatal alcohol exposure (PAE), on neurobehavioral outcomes following cerebrovascular ischemic stroke. We also assessed impact of PAE and stroke on the transcriptome of intermediary organs of the gut-brain axis. Specifically, mesenteric adipose and liver, which are supplied by portal circulation from the gut are hypothesized to mediate inflammatory and neuroprotective adaptations to stroke. Methods: Pregnant Sprague Dawley rats were exposed to either vaporized ethanol or room air from gestation day 8 to 19. At 5 months, progeny were subjected to unilateral endothelin-1 induced occlusion of the middle cerebral artery and outcomes evaluated after 2 days. Stroke induced disabilities were assessed from behavioral assays (adhesive removal, Vibrissae evoked fore-limb placement and circling) and infarct size. The liver transcriptome was assessed by sequencing, from age-matched stroke-exposed and naïve offspring. Results: PAE rats had worse neurological scores 2 days post stroke compared to control (p<0.05). We observed that the liver was substantially more transcriptionally responsive to PAE status than adipose tissue. Moreover, PAE offspring exhibited a 1.6-fold increase in upregulated genes and a 2.4-fold increase in down-regulated liver gene transcripts following stroke, compared to control offspring. Only 448 differentially expressed genes (DEGs) were common between the control and PAE groups. DEGs unique to PAE contribute to triglyceride metabolism, steroid metabolism, and cholesterol biosynthesis pathways. Weighted correlation network analysis identified 24 gene network modules, one of which, a liver proinflammatory network, was strongly correlated with post stroke neurological function (Pearson's r=-0.63, p<0.01). Conclusion: The present study shows that PAE predisposes middle-aged rat offspring for worse outcomes following cerebrovascular ischemic stroke. This effect is associated with persistent reprogramming of the liver transcriptome and an exacerbated proinflammatory response.

MED12 Regulates Human Adipose-Derived Stem Cell Adipogenesis and Mediator Kinase Subunit Expression in Murine Adipose Depots.

The mediator kinase module plays a critical role in the regulation of transcription during metabolic processes. Here we demonstrate that in human adipose-derived stem cells (hASCs), kinase module subunits have distinct mRNA and protein expression profiles during different stages of adipogenesis. In addition, siRNA-mediated loss of MED12 results in decreased adipogenesis as evident through decreased lipid accumulation and decreased expression of PPARγ, a master regulator of adipogenesis. Moreover, the decrease in adipogenesis and reduced PPARγ expression are observed only during the early stages of MED12 knockdown. At later stages, knockdown of MED12 did not have any significant effects on adipogenesis or PPARγ expression. We also observed that MED12 was present in a protein complex with PPARγ and C/EBPα during all stages of adipogenesis in hASCs. In 3T3-L1 preadipocytes and adipocytes, MED12 is present in protein complexes with PPARγ1, C/EBPα, and STAT5A. CDK8, another member of the kinase module, was only found to interact with C/EBPα. We found that the expression of all kinase module subunits decreased in inguinal, gonadal, and retroperitoneal white adipose tissue (WAT) depots in the fed state after an overnight fast, whereas the expression of kinase module subunits remained consistent in mesenteric WAT (mWAT) and brown adipose tissue. These data demonstrate that the kinase module undergoes physiologic regulation during fasting and feeding in specific mouse adipose tissue depots, and that MED12 likely plays a specific role in initiating and maintaining adipogenesis.

Differential inflammatory profile of mesenteric and omental fat in patients with colorectal cancer.

Visceral obesity (mesenteric and omental adipose tissue) is a risk factor for colorectal cancer (CRC) and weight loss can reduce risk. This study examined mesenteric and omental fat activity in patients with CRC.

Abstract MP05: The Mechanism Of The Pvat Pro-inflammatory Micro-environment Formation During The Development Of High Fat Diet-induced Hypertension

There is considerable evidence for a causative role for T cells in hypertension, including studies with immunosuppressive drugs and T cell-deficient models. Our previous studies showed that soluble mediators from mesenteric perivascular adipose tissue (mPVAT) modulate T cell function. Specifically, conditioned media from mPVAT (mPVAT-CM) from Dahl S rats on a high fat diet (HFD) promoted expression of the pro-inflammatory cytokines, IFNg, IL-17a and GM-CSF, by activated T cells. Furthermore, the Dahl S rats on HFD will later develop hypertension. Hypothesis: mPVAT is stimulated to produce immunomodulatory mediators that promotes Th1/17 differentiation preceding the development of HFD-induced hypertension. We conducted bulk RNA-seq on activated splenocytes cultured in mPVAT-CM from Dahl S rats on either control or HFD for 10 weeks. In accordance with our previous studies, PVAT-CM from HFD-fed rats significantly upregulated many genes associated with IFNg/IL-17 induction, including Mpeg1, Lyz2 and Tnfsf4 (5.0±1.78, 3.70±0.53 and 1.78±0.42 fold over Control diet, respectively). In contrast, Th2/Treg-associated genes, such as Ctla2a (-0.27±0.02) and Ccr4 (-0.41±0.03) were downregulated. We also performed single cell (sc) RNA-seq on the PVAT stromal vascular fraction (SVF) and found that acute inflammatory genes were enriched in the HFD group. Together with the bulk RNA-seq on mPVAT, these data strongly suggest that the pro-inflammatory mPVAT micro-environment may promote Th1/Th17 differentiation. To identify mediators in PVAT-CM that may induce Th1/Th17 differentiation, we compared the bulk RNA-seq on splenocytes cultured in PVAT-CM with bulk RNA-seq conducted on the whole mPVAT itself. We found that a T cell co-stimulatory receptor DPP4 (CD26), which is closely associated with T cell activation was significantly increased in mPVAT from HFD-fed rats (33.4±2.3 HFD vs. 15.3±1.8 Control diet). We also observed an increase in DPP4 global expression from mPVAT SVF in HFD-fed rats, as determined by scRNA-seq. Conclusion: The data suggest that HFD promotes the IFNg and IL-17a pathways in PVAT, which precedes hypertension in Dahl S rats and correlates with an increase in expression of DPP-4, a gene that promotes T cell activation. (NIH P01 HL070687).

Abstract 12: The Role Of Memory Gamma Delta T Cells In Hypertension And Vascular Damage

Background: We recently demonstrated that γδ T cells participate in the pathogenesis of hypertension. Evidence also suggests that memory T cells may develop during an initial hypertensive episode, sensitizing mice to develop hypertension to further mild hypertensive challenges. However, whether memory γδ T cells develop and play a role in hypertension remains unknown. Our objective is to determine if memory γδ T cells sensitize mice to develop hypertension in response to a mild hypertensive challenge. Methods: Ten-12-week-old C57BL/6J mice were exposed or not to a hypertensive challenge (490 ng/kg/min angiotensin II (Ang II), SC) for two weeks, followed by a two-week washout period, and then infused with a subpressor dose of Ang II (140 ng/kg/min Ang II, SC) for two weeks. Blood pressure was measured via telemetry and central, effector, and resident memory γδ T cells were profiled by flow cytometry. Results: Mice exposed to the first hypertensive challenge had a higher systolic blood pressure than the sham group at the end of the subpressor hypertensive challenge (149±6 vs. 122±3 mmHg, P <0.001). After 14-days of Ang II infusion, effector memory γδ T cells increased 5.2-fold in the mesenteric artery perivascular adipose tissue (PVAT, 1.25±0.37% vs. 0.24±0.12%, P <0.05), and 1.8-fold in the mesenteric lymph nodes (mLN, 1.49±0.03% vs. 0.82±0.15%, P <0.05) compared to sham treated mice. After repeated Ang II infusion, central memory γδ T cells decreased by 57% in the aortic PVAT (6.79±1.46% vs. 15.69±2.87%, P <0.05), and by 22% in the mLN (0.18±0.01% vs. 0.23±0.01%, P <0.05) compared to control mice. Conclusion: An initial exposure to a hypertensive stimulus sensitizes mice to develop hypertension to a subsequent subpressor hypertensive challenge and results in the development of memory γδ T cells.

Effects of serine palmitoyltransferase inhibition by myriocin in ad libitum-fed and nutrient-restricted ewes.

The fungal isolate myriocin inhibits serine palmitoyltransferase and de novo ceramide synthesis in rodents; however, the effects of myriocin on ceramide concentrations and metabolism have not been previously investigated in ruminants. In our study, 12 non-lactating crossbred ewes received an intravenous bolus of myriocin (0, 0.1, 0.3, or 1.0 mg/kg/body weight [BW]; CON, LOW, MOD, or HIGH) every 48 h for 17 d. Ewes consumed a high-energy diet from day 1 to 14 and were nutrient-restricted (straw only) from day 15 to 17. Blood was collected preprandial and at 1, 6, and 12 h relative to bolus and nutrient restriction. Tissues were collected following euthanasia on day 17. Plasma was analyzed for free fatty acids (FFAs), glucose, and insulin. Plasma and tissue ceramides were quantified using mass spectrometry. HIGH selectively decreased metabolizable energy intake, BW, and plasma insulin, and increased plasma FFA (Dose, P < 0.05). Myriocin linearly decreased plasma very-long-chain (VLC) ceramide and dihydroceramide (DHCer) by day 13 (Linear, P < 0.05). During nutrient restriction, fold-change in FFA was lower with increasing dose (P < 0.05). Nutrient restriction increased plasma C16:0-Cer, an effect suppressed by MOD and HIGH (Dose × Time, P < 0.05). Myriocin linearly decreased most ceramide and DHCer species in the liver and omental and mesenteric adipose, VLC ceramide and DHCer in the pancreas, and C18:0-Cer in skeletal muscle and subcutaneous adipose tissue (Linear, P ≤ 0.05). We conclude that the intravenous delivery of 0.3 mg of myriocin/kg of BW/48 h decreases circulating and tissue ceramide without modifying energy intake in ruminants.

Grape-Seed Proanthocyanidin Extract Reverts Obesity-Related Metabolic Derangements in Aged Female Rats.

Obesity and ageing are current issues of global concern. Adaptive homeostasis is compromised in the elderly, who are more likely to suffer age-related health issues, such as obesity, metabolic syndrome, and cardiovascular disease. The current worldwide prevalence of obesity and higher life expectancy call for new strategies for treating metabolic disorders. Grape-seed proanthocyanidin extract (GSPE) is reported to be effective in ameliorating these pathologies, especially in young animal models. In this study, we aimed to test the effectiveness of GSPE in modulating obesity-related pathologies in aged rats fed an obesogenic diet. To do so, 21-month-old rats were fed a high-fat/high-sucrose diet (cafeteria diet) for 11 weeks. Two time points for GSPE administration (500 mg/kg body weight), i.e., a 10-day preventive GSPE treatment prior to cafeteria diet intervention and a simultaneous GSPE treatment with the cafeteria diet, were assayed. Body weight, metabolic parameters, liver steatosis, and systemic inflammation were analysed. GSPE administered simultaneously with the cafeteria diet was effective in reducing body weight, total adiposity, and liver steatosis. However, the preventive treatment was effective in reducing only mesenteric adiposity in these obese, aged rats. Our results confirm that the simultaneous administration of GSPE improves metabolic disruptions caused by the cafeteria diet also in aged rats.

Expression of long-chain polyunsaturated fatty acids biosynthesis genes during the early life-cycle stages of the tropical gar Atractosteus tropicus.

Long-chain (≥C20) polyunsaturated fatty acids (LC-PUFA), including eicosapentaenoic acid (EPA, 20:5n-3), arachidonic acid (ARA, 20:4n-6) and docosahexaenoic acid (DHA, 22:6n-3), are essential in multiple physiological processes, especially during early development of vertebrates. LC-PUFA biosynthesis is achieved by two key families of enzymes, fatty acyl desaturases (Fads) and elongation of very long-chain fatty acid (Elovl). The present study determined the expression patterns of genes encoding desaturases (fads1 and fads2) and elongases (elovl2 and elovl5) involved in the LC-PUFA biosynthesis during early life-stages of the tropical gar Atractosteus tropicus. We further analyzed the fatty acid profiles during early development of A. tropicus to evaluate the impact of Fads and Elovl enzymatic activities. Specific oligonucleotides were designed from A. tropicus transcriptome to perform qPCR (quantitative polymerase chain reaction) on embryonic and larval stages, along with several organs (intestine, white muscle, brain, liver, heart, mesenteric adipose, kidney, gill, swim bladder, stomach, and spleen) collected from juvenile specimens. Fatty acid content of feeds and embryonic and larval stages were analyzed. Results show that fads1, fads2, elovl2 and elovl5 expression was detected from embryonic stages with expression peaks from day 15 post hatching, which could be related to transcriptional and dietary factors. Moreover, fads1, fads2 and elovl2 showed a higher expression in intestine, while elovl5 showed a higher expression in liver, suggesting that the tropical gar activates its LC-PUFA biosynthetic machinery to produce ARA, EPA and DHA to satisfy physiological demands at crucial developmental milestones during early development.

Immune spleen cells attenuate the inflammatory profile of the mesenteric perivascular adipose tissue in obese mice

The perivascular adipose tissue (PVAT) differs from other fat depots and exerts a paracrine action on the vasculature. The spleen has an important role in the immune response, and it was observed to have either a protective role or a contribution to obesity-related diseases. However, the relation between spleen and PVAT is elusive in obesity. We investigated the role of spleen in the inflammatory profile of the mesenteric PVAT (mPVAT) from mice fed a high-fat diet (HFD) for 16 weeks. Male C57Bl/6 mice were sham-operated or splenectomized (SPX) and fed a HFD for 16 weeks. mPVAT morphology was evaluated by hematoxylin and eosin staining, infiltrated immune cells were evaluated by flow cytometry, inflammatory cytokines were evaluated by ELISA and the splenic cell chemotaxis mediated by mPVAT was evaluated using a transwell assay. In SPX mice, HFD induced adipocyte hypertrophy and increased immune cell infiltration and proinflammatory cytokine levels in mPVAT. However, none of these effects were observed in mPVAT from sham-operated mice. Spleen from HFD fed mice presented reduced total leukocytes and increased inflammatory markers when compared to the spleen from control mice. Chemotaxis of spleen cells mediated by mPVAT of HFD fed mice was reduced in relation to standard diet fed mice. The spleen protects mPVAT against the effects of 16-week HFD. This information was missing, and it is important because PVAT is different from other fat depots and data cannot be extrapolated from any type of adipose tissue to PVAT.

Derivation, characterization, and in vitro cell regeneration of canine white adipose tissue-derived mesenchymal stem cells obtained from a mesenteric region

BackgroundThe study was conducted to assess the characterization, differentiation, and in vitro cell regeneration potential of canine mesenteric white adipose tissue-derived mesenchymal stem cells (AD-MSCs). The tissue was harvested through surgical incision and digested with collagenase to obtain a stromal vascular fraction. Mesenchymal stem cells isolated from the stromal vascular fraction were characterized through flow cytometry and reverse transcription-polymerase chain reaction. Assessment of cell viability, in vitro cell regeneration, and cell senescence were carried out through MTT assay, wound healing assay, and β-galactosidase assay, respectively. To ascertain the trilineage differentiation potential, MSCs were stained with alizarin red for osteocytes, alcian blue for chondrocytes, and oil o red for adipocytes. In addition, differentiated cells were characterized through a reverse transcription-polymerase chain reaction.ResultsWe observed the elongated, spindle-shaped, and fibroblast-like appearance of cells after 72 h of initial culture. Flow cytometry results showed positive expression for CD44, CD90, and negative expression for CD45 surface markers. Population doubling time was found 18–24 h for up to the fourth passage and 30±0.5 h for the fifth passage. A wound-healing assay was used to determine cell migration rate which was found 136.9 ± 4.7 μm/h. We observed long-term in vitro cell proliferation resulted in MSC senescence. Furthermore, we also found that the isolated cells were capable of differentiating into osteogenic, chondrogenic, and adipogenic lineages.ConclusionsMesenteric white adipose tissue was found to be a potential source for isolation, characterization, and differentiation of MSCs. This study might be helpful for resolving the problems regarding the paucity of information concerning the basic biology of stem cells. The large-scale use of AD-MSCs might be a remedial measure in regenerative medicine.

Peripancreatic adipose tissue protects against high-fat-diet-induced hepatic steatosis and insulin resistance in mice

Background/objectivesVisceral adiposity is associated with increased diabetes risk, while expansion of subcutaneous adipose tissue may be protective. However, the visceral compartment contains different fat depots. Peripancreatic adipose tissue (PAT) is an understudied visceral fat depot. Here, we aimed to define PAT functionality in lean and high-fat-diet (HFD)-induced obese mice.Subjects/methodsFour adipose tissue depots (inguinal, mesenteric, gonadal, and peripancreatic adipose tissue) from chow- and HFD-fed male mice were compared with respect to adipocyte size (n = 4–5/group), cellular composition (FACS analysis, n = 5–6/group), lipogenesis and lipolysis (n = 3/group), and gene expression (n = 6–10/group). Radioactive tracers were used to compare lipid and glucose metabolism between these four fat depots in vivo (n = 5–11/group). To determine the role of PAT in obesity-associated metabolic disturbances, PAT was surgically removed prior to challenging the mice with HFD. PAT-ectomized mice were compared to sham controls with respect to glucose tolerance, basal and glucose-stimulated insulin levels, hepatic and pancreatic steatosis, and gene expression (n = 8–10/group).ResultsWe found that PAT is a tiny fat depot (~0.2% of the total fat mass) containing relatively small adipocytes and many “non-adipocytes” such as leukocytes and fibroblasts. PAT was distinguished from the other fat depots by increased glucose uptake and increased fatty acid oxidation in both lean and obese mice. Moreover, PAT was the only fat depot where the tissue weight correlated positively with liver weight in obese mice (R = 0.65; p = 0.009). Surgical removal of PAT followed by 16-week HFD feeding was associated with aggravated hepatic steatosis (p = 0.008) and higher basal (p < 0.05) and glucose-stimulated insulin levels (p < 0.01). PAT removal also led to enlarged pancreatic islets and increased pancreatic expression of markers of glucose-stimulated insulin secretion and islet development (p < 0.05).ConclusionsPAT is a small metabolically highly active fat depot that plays a previously unrecognized role in the pathogenesis of hepatic steatosis and insulin resistance in advanced obesity.

A histological evaluation of pansteatitis-affected Mozambique tilapia, Oreochromis mossambicus (Peters 1852), from different geographical locations in South Africa.

Pansteatitis is the leading cause for the decline in Nile crocodile populations and the sporadic mortality of fish in the Olifants River System, South Africa. To determine the prevalence of this disease in lentic systems, Mozambique tilapia, Oreochromis mossambicus, were collected from Lake Loskop, Lake Flag Boshielo, Phalaborwa Barrage and Lake Luphephe-Nwanedi. The former three impoundments are located within the main stem of the Olifants River, while the latter, which is geographically isolated and situated in the Limpopo River System, served as a reference site. Mesenteric adipose, liver, serosa of the swim bladder, gill and the skeletal muscle of fish sampled were examined for gross and microscopic evidence of pansteatitis. Microscopically observed changes were used to statistically compare pansteatitis prevalence between samples and sites. Based on histopathological evaluation, the adipose tissue in the liver, swim bladder serosa and coelom from severely debilitated individuals showed the most significant pathological changes. Lesions indicative of steatitis were observed in fish collected from Lake Loskop (75%), Lake Flag Boshielo (22%) and Lake Luphephe-Nwanedi (15%). Further investigation is warranted to understand the pervasiveness and mechanisms driving pathological changes of pansteatitis at Lake Flag Boshielo, Phalaborwa Barrage and Lake Luphephe-Nwanedi.

Expression of Melatonin Receptor 1 in Rat Mesenteric Artery and Perivascular Adipose Tissue and Vasoactive Action of Melatonin

Melatonin is released by the pineal gland and can modulate cardiovascular system function via the G protein-coupled melatonin receptors MT1 and MT2. Most vessels are surrounded by perivascular adipose tissue (PVAT), which affects their contractility. The aim of our study was to evaluate mRNA and protein expression of MT1 and MT2 in the mesenteric artery (MA) and associated PVAT of male rats by RT-PCR and Western blot. Receptor localization was further studied by immunofluorescence microscopy. Effects of melatonin on neurogenic contractions were explored in isolated superior MA ex vivo by measurement of isometric contractile tension. MT1, but not MT2, was present in MA, and MT1 was localized mainly in vascular smooth muscle. Moreover, we proved the presence of MT1, but not MT2 receptors, in MA-associated PVAT. In isolated superior MA with intact PVAT, neuro-adrenergic contractile responses were significantly smaller when compared to arteries with removed PVAT. Pre-treatment with melatonin of PVAT-stripped arterial rings enhanced neurogenic contractions, while the potentiating effect of melatonin was not detected in preparations with preserved PVAT. We hypothesize that melatonin can stimulate the release of PVAT-derived relaxing factor(s) via MT1, which can override the direct pro-contractile effect of melatonin on vascular smooth muscle. Our results suggest that melatonin is involved in the control of vascular tone in a complex way, which is vessel specific and can reflect a sum of action on different layers of the vessel wall and surrounding PVAT.

Superior Mesenteric Artery Syndrome: A Potentially Fatal but Reversible Gastrointestinal Manifestation of Systemic Sclerosis

Superior mesenteric artery syndrome (SMAS) is a rare gastrointestinal disorder characterised by vascular compression of the third part of the duodenum, in the angle between the superior mesenteric artery (SMA) and the abdominal aorta. It presents as an uncommon cause of upper gastrointestinal obstruction. In patients with systemic sclerosis (SSc), gastrointestinal involvement may result in oesophageal dysmotility, gastroesophageal reflux disease (GERD), gastroparesis, small intestinal bacterial overgrowth (SIBO), chronic intestinal pseudoobstruction (CIPO), and fecal incontinence. Malnutrition may thus result in weight loss and reduced mesenteric and retroperitoneal adipose tissue, decreasing the angle between the SMA and aorta causing SMAS. Enteral or parenteral feeding can potentially reverse SMAS in SSc. We report a case of SMAS in an elderly female with SSc and concurrent gastrointestinal involvement, and discuss the important management considerations and potential adverse outcomes when untreated.

1946-P: Dapagliflozin Suppresses Adipose Fatty Acid Accumulation in Rats Fed on High-Fat Diet but Not on Normal Chow

SGLT2 inhibitor (SGLT2i) exerts not only on enhancement of glucose excretion but also on improvement of serum lipid profile via increase in lipid utilization as an energy source instead of glucose. That is, SGLT2i might affect the lipid storage. In the present study, we evaluated the effects of dapagliflozin (DAPA) on weight and fatty acid contents of adipose tissues. At 8 weeks of age, male rats were divided into four groups: (a) NC (n=6) fed on a standard laboratory chow (LC); (b) NC+DAPA (n=6) on the LC with 1 mg/kg/day DAPA administration; (c) HFD (n=6) on a high-fat diet (HF); (d) HFD+DAPA (n=6) on the HF with 1 mg/kg/day DAPA administration. After 7 weeks, we weighed epididymal (EPI), mesenteric (MES), retroperitoneal (RET), and inguinal subcutaneous (SUB) adipose tissues, and measured 21 adipose fatty-acid contents (μmol/g BW). As a result, adipose tissue weight in the examined four sites in HFD rats were significantly higher (P&amp;lt;0.01) than those, respectively, in NC rats. No significant differences were observed in weights of any adipose tissues or in their contents of fatty acids between the NC and NC+DAPA rats. In contrast, MES weight in HFD+DAPA rats was significantly lower (P&amp;lt;0.05) than that in the HFD rats. Contents of 1, 3, 2 and 1 saturated fatty acids (SFAs) in EPI, MES, RET and SUB, respectively, in the HFD+DAPA rats were significantly lower (P&amp;lt;0.05) than those, respectively, in the HFD rats. Contents of 3 and 2 monounsaturated fatty acids in MES and SUB, respectively, and contents of 2 and 1 polyunsaturated fatty acids in MES and RET, respectively, in the HFD+DAPA rats were significantly lower (P&amp;lt;0.05) than those, respectively, in the HFD rats. These results suggest that DAPA could reduce some SFAs in any adipose tissues in HF-fed rats, but not in LC-fed rats. The reduction might sometimes arise without concomitant decrease in tissue weight. In addition, DAPA might suppress accumulation of a wide range of fatty acids in MES of HF-fed rats in particular, probably due to their consumption. Disclosure D. Sato: None. J. Amarume: None. M. Yano: None. Y. Umehara: None. M. Kusunoki: Other Relationship; Self; Kaken Pharmaceutical Co., Ltd., Ono Pharmaceutical Co., Ltd., Taisho Pharmaceutical Co., Ltd. Z. Feng: None. T. Nakamura: Research Support; Self; AstraZeneca K.K., Ono Pharmaceutical Co., Ltd. Funding Ono Pharmaceutical Co., Ltd.; AstraZeneca K.K.

Abstract P3025: Secretion Of Pro-inflammatory Cytokines By Activated T Cells Cultured In Pvat-conditioned Media From Dahl S Rats On A High Fat Diet Occurs Early During Development Of Hypertension

There is considerable evidence for a role for the immune system in the development of hypertension, however the exact nature of this role is currently being characterized. Specifically, T cells have been identified as one of the immune cell types that contributes to hypertension. Our previous studies demonstrated that mesenteric perivascular adipose tissue (mPVAT) harbors a large T cell population. In the present study, we tested the hypothesis that soluble mediators in mPVAT influence T cell function during hypertension. Toward this end, we utilized a unique model of hypertension in which Dahl S rats on a high fat/high calorie diet develop hypertension by 17 weeks of age, whereas Dahl S rats on normal rodent chow do not. We found that conditioned media from mPVAT from Dahl S rats on a high fat diet markedly increased activated T cell production of the pro-inflammatory cytokines, GM-CSF, IFNγ and IL-17a as compared to cytokine production by T cells cultured in mPVAT-conditioned media from rats on normal control chow (Table 1). These cytokines would be expected to cause pleiotropic inflammatory effects, including increasing the numbers and activation of macrophages and neutrophils, among other effects. Conversely, the anti-inflammatory cytokine, IL-10, was not different between the groups, suggesting the effect is selective for inflammatory cytokines. Taken together, these data strongly suggest soluble mediators from PVAT influence T cell inflammatory status early during the development of hypertension triggered by high fat diet. Overall, the data provide evidence for a role for T cells in high fat diet-associated hypertension. (This study was supported by NIH grant P01 HL070687)

Supplementation with biscuits enriched with hesperidin and naringenin is associated with an improvement of the Metabolic Syndrome induced by a cafeteria diet in rats

• Cafeteria (CAF) diet-fed rats developed Metabolic Syndrome (MetS). • Hesperidin and naringenin-enriched biscuits (HN) ameliorated MetS in CAF rats. • HN in CAF rats decreased abdominal obesity, blood pressure and insulin resistance. • HN in CAF rats decreased total cholesterol, LDL-C and oxidative stress. • HN in standard chow-fed normoweight rats decreased LDL-C and increased HDL-C. Metabolic syndrome (MetS) has become a major public health concern. Because of their numerous health-promoting biological properties, polyphenols are potential candidates to ameliorate MetS and, recently, the incorporation of these compounds into widely consumed foodstuffs has emerged as a potential strategy to enhance their intake. Therefore, we aimed to assess the potential beneficial effects of biscuits enriched with the citrus polyphenols hesperidin and naringenin (HN) in rats that were fed either standard chow (STD) or an obesogenic cafeteria diet (CAF) for 16 weeks. The STD and CAF groups were supplemented with either control or HN biscuits for the final 8 weeks of the study. CAF-fed rats developed MetS, characterized by obesity, insulin resistance, hypertension and dyslipidemia. HN supplementation in CAF-fed rats ameliorated hypertension and insulin resistance and significantly reduced body weight, mesenteric adiposity, total cholesterol, LDL-C and oxidative stress. Hence, HN biscuits may be a promising functional food against MetS.

STAT4 programs CD103− tissue-resident memory cells during infection

Abstract Tissue-resident memory (Trm) CD8+ T cells represent a distinct population of memory T cells that are maintained independently of the circulation and are positioned to respond rapidly to reinfection of the tissue. Using the bacterial pathogen Yersinia pseudotuberculosis (Yptb), we identified two distinct intestinal CD8+ Trm populations that are differentiated by their expression of the integrin CD103. Proximity of T cells to areas of inflammation within the intestinal tissue regulated Trm differentiation, with IL-12 leading to increased numbers of CD103− Trm cells. Therefore, we examined the role of the transcription factor STAT4 in the programming of this Trm subset. During infection, both wild-type and Stat4−/− T cells expanded and entered the intestinal tissue at similar rates. Stat4−/− T cells localized to areas of inflammation along with wild-type cells, but failed to express CD103− Trm signature genes. After infection, Stat4−/− CD103+ intestinal Trm cells formed a stable memory population; however, the number of Stat4−/− CD103− Trm cells was significantly reduced relative to wild-type Trm cells. We also observed impaired persistence of Stat4−/− CD103− Trm cells in other tissues with prominent CD103− Trm populations, including the liver, colon, and mesenteric adipose. RNA-seq analysis of wild-type and Stat4−/− CD103− Trm populations was used to identify genes required for the maintenance of this Trm subset. This work has identified STAT4 as a regulator of CD103− Trm differentiation and maintenance across multiple tissues, and these results will help identify strategies to maximize the number and persistence of Trm cells during vaccination and allow us to address the role of Trm heterogeneity in tissue-specific immunity.