High-fat Feeding Research Articles

Impact of Ghrelin on Islet Size in Nonpregnant and Pregnant Female Mice.

Reducing ghrelin by ghrelin gene knockout (GKO), ghrelin-cell ablation, or high-fat diet feeding increases islet size and β-cell mass in male mice. Here we determined if reducing ghrelin also enlarges islets in females and if pregnancy-associated changes in islet size are related to reduced ghrelin. Islet size and β-cell mass were larger (P = .057 for β-cell mass) in female GKO mice. Pregnancy was associated with reduced ghrelin and increased liver-expressed antimicrobial peptide-2 (LEAP2; a ghrelin receptor antagonist) in wild-type mice. Ghrelin deletion and pregnancy each increased islet size (by ∼19.9-30.2% and ∼34.9-46.4%, respectively), percentage of large islets (>25 µm2×103, by ∼21.8-42% and ∼21.2-41.2%, respectively), and β-cell mass (by ∼15.7-23.8% and ∼65.2-76.8%, respectively). Neither islet cross-sectional area, β-cell cross-sectional area, nor β-cell mass correlated with plasma ghrelin, although all positively correlated with LEAP2 (P = .081 for islet cross-sectional area). In ad lib-fed mice, there was an effect of pregnancy, but not ghrelin deletion, to change (raise) plasma insulin without impacting blood glucose. Similarly, there was an effect of pregnancy, but not ghrelin deletion, to change (lower) blood glucose area under the curve during a glucose tolerance test. Thus, genetic deletion of ghrelin increases islet size and β-cell cross-sectional area in female mice, similar to males. Yet, despite pregnancy-associated reductions in ghrelin, other factors appear to govern islet enlargement and changes to insulin sensitivity and glucose tolerance in the setting of pregnancy. In the case of islet size and β-cell mass, one of those factors may be the pregnancy-associated increase in LEAP2.

The combined exposure of polystyrene microplastics and high-fat feeding affects the intestinal pathology damage and microbiome in zebrafish.

The pervasive utilization of plastics and their integration into ecosystems has resulted in significant environmental issues, particularly the pollution of microplastics (MPs). In aquaculture, high-fat feed (HFD) is frequently employed to enhance the energy intake and economic fish production. This study utilized zebrafish as a model organism to investigate the impact of concurrent exposure to HFD and MPs on fish intestinal pathology damage and intestinal microbiome. The experimental design involved the division of zebrafish into two groups: one receiving a normal diet (ND) and the other receiving HFD. The zebrafish were exposed to a control group, as well as polystyrene (PS) MPs of varying sizes (5 and 50 μm). Histopathological examination revealed that the combination of 5 μm MPs and HFD resulted in the most significant damage to the zebrafish intestinal tract. Furthermore, gut microbiome assays indicated that exposure to MPs and HFD altered the composition of the gut microbiome. This study demonstrates that in aquaculture, the issue of HFD must be considered alongside concerns about MPs contamination, as both factors appear to have a combined effect on the intestinal pathology damage and intestinal microbiome. The findings of this research offer valuable insights for the improvement of fish farming practices.

A Preliminary Study on the Effect of Replacing Part of Fishmeal by Brewer’s Yeast in Feeding Taiwan Loach

In this experiment, brewer’s yeast was used to replace part of the fish meal in the feed to formulate a high-fat and low-protein feed for Taiwan loach. The effects of brewer’s yeast on the growth performance, muscle quality, hepatopancreas and pancreas carnitine content, intestinal flora, immunity, and antioxidant ability of Taiwan loach were preliminarily investigated. In experiment 1, 600 Taiwan loaches were randomly divided into 4 groups, and 1% (group A), 4% (group B), 8% (group C), and 12% (group D) of brewer’s yeast was substituted for an equal amount of fishmeal in the basal diets. The loaches in each group were fed for 60 d. In experiment 2, 60 Taiwan loaches were selected and randomly divided into a control group (Group E) and a test group (Group F). The loaches were fed the basal diet and the high-fat and low-protein diet supplemented with 8% fishmeal, replaced by brewer’s yeast. The experiment lasted for 60 days, and the growth performance, hepatopancreas carnitine content, muscle quality, intestinal flora, plasma antioxidant, and immune capacity indices of loaches in each group were determined. The results were as follows: the weight gain rate and specific growth rate were significantly higher in group C than those in groups A, B, and D (P < 0.05); the intestinal length ratio, muscle hardness, hepatopancreatic carnitine content, plasma superoxide dismutase activity, catalase activity, total antioxidant capacity, and lysozyme activity were significantly greater in group F than those in group E (P < 0.05); the Lactobacillus and Bifidobacterium counts in Group F were considerably higher than those in Group E (P < 0.05), and the Salmonella counts in Group F was significantly lower than that in Group E (P < 0.05); the survival rate, weight gain rate, bait coefficient, muscle crude protein, crude fat, viscosity, elasticity, cohesion, chewability, and restorative capacity were not significantly different between Group F and Group E (P > 0.05). The above results showed that adding 8% brewer’s yeast to feed Taiwan loach instead of fish meal could enhance its hepatopancreatic carnitine synthesis, optimize the intestinal flora, improve the body’s immune and antioxidant ability, and have a certain promotional effect on the intestinal development and muscle quality improvement.

Hepatoprotective and cardioprotective effects of empagliflozin in spontaneously hypertensive rats fed a high-fat diet

A combination of liver and heart dysfunction worsens the prognosis of human survival. The aim of this study was to investigate whether empagliflozin (a sodium-glucose transporter-2 inhibitor) has beneficial effects not only on cardiac and renal function but also on hepatic function. Adult (6-month-old) male spontaneously hypertensive rats (SHR) were fed a high-fat diet (60% fat) for four months to induce hepatic steatosis and mild heart failure. For the last two months, the rats were treated with empagliflozin (empa, 10 mg.kg-1.day-1 in the drinking water). Renal function and oral glucose tolerance test were analyzed in control (n=8), high-fat diet (SHR+HF, n=10), and empagliflozin-treated (SHR+HF+empa, n=9) SHR throughout the study. Metabolic parameters and echocardiography were evaluated at the end of the experiment. High-fat diet feeding increased body weight and visceral adiposity, liver triglyceride and cholesterol concentrations, and worsened glucose tolerance. Although the high-fat diet did not affect renal function, it significantly worsened cardiac function in a subset of SHR rats. Empagliflozin reduced body weight gain but not visceral fat deposition. It also improved glucose sensitivity and several metabolic parameters (plasma insulin, uric acid, and HDL cholesterol). In the liver, empagliflozin reduced ectopic lipid accumulation, lipoperoxidation, inflammation and pro-inflammatory HETEs, while increasing anti-inflammatory EETs. In addition, empagliflozin improved cardiac function (systolic, diastolic and pumping) independent of blood pressure. The results of our study suggest that hepatoprotection plays a decisive role in the beneficial effects of empagliflozin in preventing the progression of cardiac dysfunction induced by high-fat diet feeding.

Involution of brown adipose tissue through a Syntaxin 4 dependent pyroptosis pathway

Aging, chronic high-fat diet feeding, or housing at thermoneutrality induces brown adipose tissue (BAT) involution, a process characterized by reduction of BAT mass and function with increased lipid droplet size. Single nuclei RNA sequencing of aged mice identifies a specific brown adipocyte population of Ucp1-low cells that are pyroptotic and display a reduction in the longevity gene syntaxin 4 (Stx4a). Similar to aged brown adipocytes, Ucp1-STX4KO mice display loss of brown adipose tissue mass and thermogenic dysfunction concomitant with increased pyroptosis. Restoration of STX4 expression or suppression of pyroptosis activation protects against the decline in both mass and thermogenic activity in the aged and Ucp1-STX4KO mice. Mechanistically, STX4 deficiency reduces oxidative phosphorylation, glucose uptake, and glycolysis leading to reduced ATP levels, a known triggering signal for pyroptosis. Together, these data demonstrate an understanding of rapid brown adipocyte involution and that physiologic aging and thermogenic dysfunction result from pyroptotic signaling activation.

TM4SF19-mediated control of lysosomal activity in macrophages contributes to obesity-induced inflammation and metabolic dysfunction

Adipose tissue (AT) adapts to overnutrition in a complex process, wherein specialized immune cells remove and replace dysfunctional and stressed adipocytes with new fat cells. Among immune cells recruited to AT, lipid-associated macrophages (LAMs) have emerged as key players in obesity and in diseases involving lipid stress and inflammation. Here, we show that LAMs selectively express transmembrane 4 L six family member 19 (TM4SF19), a lysosomal protein that represses acidification through its interaction with Vacuolar-ATPase. Inactivation of TM4SF19 elevates lysosomal acidification and accelerates the clearance of dying/dead adipocytes in vitro and in vivo. TM4SF19 deletion reduces the LAM accumulation and increases the proportion of restorative macrophages in AT of male mice fed a high-fat diet. Importantly, male mice lacking TM4SF19 adapt to high-fat feeding through adipocyte hyperplasia, rather than hypertrophy. This adaptation significantly improves local and systemic insulin sensitivity, and energy expenditure, offering a potential avenue to combat obesity-related metabolic dysfunction.

Trk-fused gene plays a critical role in diet-induced adipose tissue expansion and is also involved in thyroid hormone action.

Mutations in the Trk-fused gene (TFG) cause hereditary motor and sensory neuropathy with proximal dominant involvement, which reportedly has high co-incidences with diabetes and dyslipidemia, suggesting critical roles of the TFG in metabolism as well. We found that TFG expression levels in white adipose tissues (WATs) were elevated in both genetically and diet-induced obese mice and that TFG deletion in preadipocytes from the stromal vascular fraction (SVF) markedly inhibited adipogenesis. To investigate its role in vivo, we generated tamoxifen-inducible adipocyte-specific TFG knockout (AiTFG KO) mice. While a marked down-regulation of the peroxisome proliferator-activated receptor gamma target, de novo lipogenesis (DNL), and mitochondria-related gene expressions were observed in subcutaneous WAT (scWAT) from AiTFG KO mice, these effects were blunted in SVF-derived adipocytes when the TFG was deleted after differentiation into adipocytes, implying cell nonautonomous effects. Intriguingly, expressions of thyroid hormone receptors, as well as carbohydrate responsive element-binding protein β, which mediates the metabolic actions of thyroid hormone, were drastically down-regulated in scWAT from AiTFG KO mice. Reduced DNL and thermogenic gene expressions in AiTFG KO mice might be attributable to impaired thyroid hormone action in vivo. Finally, when adipocyte TFG was deleted in either the early or the late phase of high-fat diet feeding, the former brought about an impaired expansion of epididymal WAT, whereas the latter caused prominent adipocyte cell death. TFG deletion in adipocytes markedly exacerbated hepatic steatosis in both experimental settings. Collectively, these observations indicate that the TFG plays essential roles in maintaining normal adipocyte functions, including an enlargement of adipose tissue, thyroid hormone function, and thermogenic gene expressions, and in preserving hypertrophic adipocytes.

Danggui Shaoyao powder improves hepatic lipid metabolism in atherosclerosis mice via PPARγ-LXRα-ABCA1 pathway regulation

ObjectiveTo observe the effects of Danggui Shaoyao powder (DSP) on hepatic lipid metabolism and further explore its mechanism of action by peroxisome proliferator-activated receptor (PPARγ)-liver X receptor (LXRα)-adenosine triphosphate (ATP)-binding cassette transporter A1 (ABCA1) pathway regulation. MethodsEight C57BL/6J male mice were selected as the control group, and 24 ApoE−/− male mice were randomly divided into the atherosclerosis model (AS) group, atorvastatin calcium (AC) group, and DSP group (n = 8 each group). To establish an AS model, ApoE−/− mice were fed a high-fat diet for 16 weeks. Pathologic changes in the aortic vasculature and liver were identified using Oil Red O staining. Triglyceride (TG), cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) levels were determined in the livers using a single-reagent GPO-PAP method. Fluorescence quantitative polymerase chain reaction and western blot were used to observe and evaluate the mRNA and protein expression of the PPARγ-LXRα-ABCA1 intermediates in the liver. ResultsAfter 16 weeks of a high-fat diet, ApoE−/− mice showed more Oil Red O staining in the aorta and liver compared to the CONT group. Compared to the AS group, the DSP and AC treatment reduced aortic plaque and hepatic lipid deposition to varying degrees. Furthermore, DSP significantly reduced the hepatic lipid area in ApoE−/− mice (P < .001) and decreased the levels of TG, TC, and LDL-C in liver (P < .001, P = .027, P < .001, respectively). DSP also significantly increased the levels of PPARγ, LXRα, ABCA1, and ABCG1 mRNA expression, as well as the PPARγ, LXRα, ABCA1, and ABCG1 protein expression in liver. ConclusionDSP improved hepatic lipid metabolism via PPARγ-LXRα-ABCA1 pathway modulation for AS treatment.

Activation of α7 nAChR improves white fat homeostasis and promotes beige adipogenesis and thermogenesis in obese mice

To investigate the effects of α7 nicotinic acetylcholine receptor (nAChR) agonist on β3-adrenoceptor agonist-induced impairment of white fat homeostasis and beige adipose formation and heat production in obese mice. Forty obese C57BL/6J mice were randomized into high-fat feeding group, β3-adrenoceptor agonist-treated model group, α7 nAChR agonist group, and α7 nAChR inhibitor group (n=10), with another 10 mice with normal feeding as the blank control group. White adipose tissue from the epididymis of the mice were sampled for HE staining of the adipocytes. The expression levels of TNF-α, IL-1β, IL-10 and TGF-β in the white adipose tissue were determined by ELISA, and the mRNA levels of iNOS, Arg1, UCP-1, PRDM-16 and PGC-1α were detected using RT-qPCR. Western blotting was performed to detect the expression levels of NF-κB P65, p-JAK2, p-STAT3 in the white adipose tissue. Compared with those in the blank control group, the mice with high-fat feeding showed significantly increased body weight, more fat vacuoles in the white adipose tissue, increased volume of lipid droplets in the adipocytes, upregulated iNOS mRNA expression and protein expression of TNF-α and IL-1β, and lowered expression of Arg-1 mRNA and IL-10 and TGF-β proteins (P < 0.01). Treatment with α7 nAChR significantly reduced mRNA levels of PRDM-16, PGC-1α and UCP-1, lowered TNF-α and IL-1β expressions, increased IL-10 and TGF-β expressions, and reduced M1/M2 macrophage ratio in the white adipose tissues (P < 0.05 or 0.01). Activation of α7 nAchR improves white adipose tissue homeostasis impairment induced by β3 agonist, promotes transformation of M1 to M2 macrophages, reduces inflammatory response in white adipose tissue, and promote beige adipogenesis and thermogenesis in obese mice.

Heparanase promotes the onset and progression of atherosclerosis in apolipoprotein E gene knockout mice

Background and aimsAtherosclerosis is the primary underlying cause of myocardial infarction and stroke, which are the major causes of death globally. Heparanase (Hpse) is a pro-inflammatory extracellular matrix degrading enzyme that has been implicated in atherogenesis. However, to date the precise roles of Hpse in atherosclerosis and its mechanisms of action are not well defined. This study aims to provide new insights into the contribution of Hpse in different stages of atherosclerosis in vivo. MethodsWe generated Hpse gene-deficient mice on the atherosclerosis-prone apolipoprotein E gene knockout (ApoE−/−) background to investigate the impact of Hpse gene deficiency on the initiation and progression of atherosclerosis after 6 and 14 weeks high-fat diet feeding, respectively. Atherosclerotic lesion development, blood serum profiles, lesion composition and aortic immune cell populations were evaluated. ResultsHpse-deficient mice exhibited significantly reduced atherosclerotic lesion burden in the aortic sinus and aorta at both time-points, independent of changes in plasma cholesterol levels. A significant reduction in the necrotic core size and an increase in smooth muscle cell content were also observed in advanced atherosclerotic plaques of Hpse-deficient mice. Additionally, Hpse deficiency reduced circulating and aortic levels of VCAM-1 at the initiation and progression stages of disease and circulating MCP-1 levels in the initiation but not progression stage. Moreover, the aortic levels of total leukocytes and dendritic cells in Hpse-deficient ApoE−/− mice were significantly decreased compared to control ApoE−/−mice at both disease stages. ConclusionsThis study identifies Hpse as a key pro-inflammatory enzyme driving the initiation and progression of atherosclerosis and highlighting the potential of Hpse inhibitors as novel anti-inflammatory treatments for cardiovascular disease.

Metabolic Fluxes in the Renal Cortex Are Dysregulated InVivo in Response to High-Fat Diet.

Diabetes and obesity are risk factors for kidney disease. While renal glucose production increases in diabetes, recent data suggest that gluconeogenic and oxidative capacity decline in kidney disease. Thus, metabolic dysregulation caused by diet-induced insulin resistance may sensitize the kidney for a loss in function. Here we examined how diet-induced insulin resistance disrupts mitochondrial metabolic fluxes in the renal cortex in vivo. C57Bl/6J mice were rendered insulin resistant through high-fat (HF) feeding; anaplerotic, cataplerotic, and oxidative metabolic fluxes in the cortex were quantified through 13C-isotope tracing during a hyperinsulinemic-euglycemic clamp. As expected, HF-fed mice exhibited increased body weight, gluconeogenesis, and systemic insulin resistance compared to chow-fed mice. Relative to the citric acid cycle, HF-feeding increased metabolic flux through pyruvate carboxylation (anaplerosis) and phosphoenolpyruvate carboxykinase (cataplerosis) while decreasing flux through the pyruvate dehydrogenase complex in the cortex. Furthermore, the relative flux from non-pyruvate sources of acetyl-CoA profoundly increased in the cortex of HF-fed mice, correlating with a marker of oxidative stress. The data demonstrate that HF-feeding spares pyruvate from dehydrogenation at the expense of increasing cataplerosis, which may underpin renal gluconeogenesis during insulin resistance; the results also support the hypothesis that dysregulated oxidative metabolism in the kidney contributes to metabolic disease.

Histopatologi Hepar Tikus Dengan Induksi Pakan Tinggi Lemak Setelah Pemberian Biji Mahoni

High accumulation of lipids in hepatocytes can trigger an increase in the production of radical compounds, leading to fatty liver disease. This condition induces histological changes in the liver, especially in hepatocytes, and affects the surrounding structures. Mahogany seeds have the potential to act as a hypolipidemic agent in treating fatty liver. Mahogany seeds are known to contain phytochemical compounds which act as antioxidants. This study aimed to determine liver histopathology of rats by inducing high-fat diet after giving mahogany seeds ethanol extract which was observed through the percentage of steatosis, hepatocyte diameter, and hepatosomatic index. This study involved thirty male Sprague Dawley rats, divided into 6 groups: P0 (given commercial feed), P1 (given high-fat diet), P2 (given high-fat diet and simvastatin at a dose of 8 mg/200 g BW), P3, P4, and P5 (given high-fat diet and mahogany seeds ethanol extract at a dose of 14, 28, and 56 mg/200 g BW). The results showed that the hepatosomatic index among all treatment groups did not differ significantly; however, the percentage of steatosis and hepatocyte diameter in the groups given mahogany seeds ethanol extract significantly differed from the group given only high-fat feed. Based on these results, it can be concluded that mahogany seed ethanol extract can maintain the histological structure of the liver in male Sprague Dawley rats with fatty liver. Keywords: hepatocyte, hepatosomatic index, high-fat diet, mahogany seeds, steatosis

Long-Term Effects of Maternal Fat Consumption on the Brain Transcriptome of Obesogenic Diet-Fed Young Adult Mice Offspring

BackgroundSubstantial evidence has demonstrated that maternal high-fat (HF) consumption during gestation and lactation plays as a risk factor for neurodevelopmental alterations and subsequent neurological disorders. ObjectiveWe investigated the regulatory mechanisms of maternal fat consumption on brain development and function in offspring at different ages. MethodsMouse dams were fed either a control diet [low-fat (LF)] or an HF diet for 3 wk before mating and throughout pregnancy and lactation. Offspring were killed at postnatal day (PD) 21 (LF21 and HF21), and the rest were fed an HF diet for 12 wk until the killing at PD 105 (LF105 and HF105). The expression levels of genes and proteins in the brains of offspring were analyzed by microarray and immunoblotting, respectively. ResultsMaternal dietary fat content, offspring age, and their interaction affected the expression levels of 1215, 10,453, and 2105 genes, respectively. The 67 differentially expressed genes (DEGs) between the HF21 and LF21 groups were enriched in several Gene Ontology terms related to nervous system development. Among 45 DEGs of the HF105/LF105 comparison, several genes associated with neurotransmitter action are detected. In addition, we observed increased activation of the AMP-dependent protein kinase–cAMP response element binding protein signaling pathway in HF105/LF105 comparison. However, maternal fat content did not change the protein levels of amyloid-β and tau hyperphosphorylation, the markers of neuropathogenesis. ConclusionsMaternal HF feeding altered the expression of genes involved in the development and neurotransmitter system in the brains of PD 21 and HF diet-fed PD 105 offspring, respectively. Especially, the absence of overlap between DEGs at each comparison highlights the dynamic nature of alterations in gene expression in offspring of dams fed an HF diet. Further investigation on older adult offspring is necessary to elucidate the effects of maternal fat intake on the brain pathophysiology of offspring.

STAP-2 facilitates insulin signaling through binding to CAP/c-Cbl and regulates adipocyte differentiation

Signal-transducing adaptor protein-2 (STAP-2) is an adaptor molecule involved in several cellular signaling cascades. Here, we attempted to identify novel STAP-2 interacting molecules, and identified c-Cbl associated protein (CAP) as a binding protein through the C-terminal proline-rich region of STAP-2. Expression of STAP-2 increased the interaction between CAP and c-Cbl, suggesting that STAP-2 bridges these proteins and enhances complex formation. CAP/c-Cbl complex is known to regulate GLUT4 translocation in insulin signaling. STAP-2 overexpressed human hepatocyte Hep3B cells showed enhanced GLUT4 translocation after insulin treatment. Elevated levels of Stap2 mRNA have been observed in 3T3-L1 cells and mouse embryonic fibroblasts (MEFs) during adipocyte differentiation. The differentiation of 3T3-L1 cells into adipocytes was highly promoted by retroviral overexpression of STAP-2. In contrast, STAP-2 knockout (KO) MEFs exhibited suppressed adipogenesis. The increase in body weight with high-fat diet feeding was significantly decreased in STAP-2 KO mice compared to WT animals. These data suggest that the expression of STAP-2 correlates with adipogenesis. Thus, STAP-2 is a novel regulatory molecule that controls insulin signal transduction by forming a c-Cbl/STAP-2/CAP ternary complex.

Distribution of Zinc in Muscle, Adipose Tissue and Blood Serum of Rats Under Conditions of Zinc-Deficient, Iodine-Deficient, High-Carbohydrate and High-Fat Diets

The relevance of the study is due to the prevalence of hypothyroid dysfunction, type II diabetes mellitus, and metabolic syndrome. The study was carried out on sexually mature male rats that were on a standard vivarium diet (control group), zinc-deficient, iodine-deficient, high-carbohydrate and high-fat diets. Under the experimental conditions, the distribution of zinc in blood serum, adipose (visceral fat) and muscle (femoral and tibial muscles) tissues was studied. The study showed a decrease in serum zinc content by 13.79-30.89 % (p&lt;0.05) compared to the control group, regardless of diet. The concentration of the trace element in adipose tissue was significantly reduced relative to the control under conditions of zinc deprivation (by 18.37 %, p&lt;0.05), and especially high-fat feeding (by 74.74 %, p&lt;0.001). The increase in the content of the trace element in muscles under conditions of zinc deficiency (by 36.84 %, p&lt;0.001) compared to the same indicator in animals fed a standard diet) is noteworthy. Taking into account the role of the bioelement in the maintenance of thyroid homeostasis, carbohydrate metabolism, and antioxidant potential, the detected changes involving zinc may act as a trigger for changes in the hormonal profile, metabolic and oxidative disorders.

Prior Exposure to Experimental Preeclampsia Increases Atherosclerotic Plaque Inflammation in Atherogenic Mice-Brief Report.

Women with a history of preeclampsia have evidence of premature atherosclerosis and increased risk of myocardial infarction and stroke compared with women who had a normotensive pregnancy. Whether this is due to common risk factors or a direct impact of prior preeclampsia exposure has never been tested in a mouse atherosclerosis model. Pregnant LDLR-KO (low-density lipoprotein receptor knockout; n=35) female mice were randomized in midgestation to sFlt1 (soluble fms-like tyrosine kinase 1)-expressing adenovirus or identical control adenovirus. Postpartum, mice were fed high-fat diet for 8 weeks to induce atherogenesis. Comparison between the control and preeclampsia models was made for metabolic parameters, atherosclerosis burden and composition by histology, plaque inflammation by flow cytometry, and aortic cytokines and inflammatory markers using a cytokine array. In pregnant LDLR-KO mice, sFlt1 adenovirus significantly induced serum sFlt1, blood pressure, renal endotheliosis, and decreased pup viability. After 8 weeks of postpartum high fat feeding, body weight, fasting glucose, plasma cholesterol, HDL (high-density lipoprotein), and LDL (low-density lipoprotein) were not significantly different between groups with no change in aortic root plaque size, lipid content, or necrotic core area. Flow cytometry demonstrated significantly increased CD45+ aortic arch leukocytes and CD3+T cells and aortic lysate contained more CCL (CC motif chemokine ligand) 22 and fetuin A and decreased expression of IGFBP6 (insulin-like growth factor-binding protein 6) and CCL21 in preeclampsia-exposed mice compared with controls. In atherogenic LDLR-KO mice, exposure to sFlt1-induced preeclampsia during pregnancy increases future atherosclerotic plaque inflammation, supporting the concept that preeclampsia directly exacerbates atherosclerotic inflammation independent of preexisting risk factors. This mechanism may contribute to ischemic vascular disease in women after preeclampsia pregnancy.

Adipose tissue peroxisomal lipid synthesis orchestrates obesity and insulin resistance through LXR-dependent lipogenesis

ObjectiveAdipose tissue mass is maintained by a balance between lipolysis and lipid storage. The contribution of adipose tissue lipogenesis to fat mass, especially in the setting of high-fat feeding, is considered minor. Here we investigated the effect of adipose-specific inactivation of the peroxisomal lipid synthetic protein PexRAP on fatty acid synthase (FASN)-mediated lipogenesis and its impact on adiposity and metabolic homeostasis. MethodsTo explore the role of PexRAP in adipose tissue, we metabolically phenotyped mice with adipose-specific knockout of PexRAP. Bulk RNA sequencing was used to determine transcriptomic responses to PexRAP deletion and 14C-malonyl CoA allowed us to measure de novo lipogenic activity in adipose tissue of these mice. In vitro cell culture models were used to elucidate the mechanism of cellular responses to PexRAP deletion. ResultsAdipose-specific PexRAP deletion promoted diet-induced obesity and insulin resistance through activation of de novo lipogenesis. Mechanistically, PexRAP inactivation inhibited the flux of carbons to ethanolamine plasmalogens. This increased the nuclear PC/PE ratio and promoted cholesterol mislocalization, resulting in activation of liver X receptor (LXR), a nuclear receptor known to be activated by increased intracellular cholesterol. LXR activation led to increased expression of the phospholipid remodeling enzyme LPCAT3 and induced FASN-mediated lipogenesis, which promoted diet-induced obesity and insulin resistance. ConclusionsThese studies reveal an unexpected role for peroxisome-derived lipids in regulating LXR-dependent lipogenesis and suggest that activation of lipogenesis, combined with dietary lipid overload, exacerbates obesity and metabolic dysregulation.

Protective effect of SERCA2a-SUMOylation by SUMO-1 on diabetes-induced atherosclerosis and aortic vascular injury.

Diabetes is a major risk factor for cardiovascular disease. However, the exact mechanism by which diabetes contributes to vascular damage is not fully understood. The aim of this study was to investigate the role of SUMO-1 mediated SERCA2a SUMOylation in the development of atherosclerotic vascular injury associated with diabetes mellitus.ApoE-/- mice were treated with streptozotocin (STZ) injection combined with high-fat feeding to simulate diabetic atherosclerosis and vascular injury. Human aortic vascular smooth muscle cells (HAVSMCs) were treated with high glucose (HG, 33.3 mM) and palmitic acid (PA, 200 µM) for 24h to mimic a model of diabetes-induced vascular injury in vitro. Aortic vascular function, phenotypic conversion, migration, proliferation, intracellular Ca2+ concentration, the levels of small ubiquitin-like modifier type 1 (SUMO1), SERCA2a and SUMOylated SERCA2a were detected.Diabetes-induced atherosclerotic mice presented obvious atherosclerotic plaques and vascular injury, companied by significantly lower levels of SUMO1 and SERCA2a in aorta. HG and PA treatment in HAVSMCs reduced the expressions of SUMO1, SERCA2a and SUMOylated SERCA2a, facilitated the HAVSMCs phenotypic transformation, proliferation and migration, attenuated the Ca2+ transport, and increased the resting intracellular Ca2+ concentration. We also confirmed that SUMO1 directly bound to SERCA2a in HAVSMCs. Overexpression of SUMO1 restored the function and phenotypic contractile ability of HAVSMCs by upregulating SERCA2a SUMOylation, thereby alleviating HG and PA-induced vascular injury.These observations suggest an essential role of SUMO1 to protect diabetes-induced atherosclerosis and aortic vascular injury by the regulation of SERCA2a-SUMOylation and calcium homeostasis.

The Anti-Atherosclerotic Effects of Buyang Huanwu Decoction through M1 and M2 Macrophage Polarization in an ApoE Knockout Mouse Model.

Arteriosclerosis (AS) is a chronic inflammatory disease and Buyang Huanwu decoction (BHD) has been identified as an anti-atherosclerosis effect, and the study is aimed to investigate the underlying mechanism. The E4 allele of Apolipoprotein E (ApoE) is associated with both metabolic dysfunction and an enhanced pro-inflammatory response, ApoE-knockout (ApoE-/-) mice were fed with a high-fat diet to establish an arteriosclerosis model and treated with BHD or atorvastatin (as a positive control). The atherosclerotic plaque in each mouse was evaluated using Oil red O Staining. Elisa kits were used to evaluate blood lipid, interleukin-6 (IL-6), IL-1 beta (IL-1β), tumor necrosis factor alpha (TNF-α), IL-4, IL-10, and tumor growth factor beta (TGF-β) contents, while Western blot was applicated to measure inducible nitric oxide synthase (iNOS), arginase I (Arg-1) expression. Meanwhile, pyruvate kinase M2 (PKM2), hypoxia-inducible factor-1 alpha (HIF-1α) and its target genes glucose transporter type 1 (GLUT1), lactate dehydrogenase A (LDHA), and 3-phosphoinositide-dependent kinase 1 (PDK1), as well as IL-6, IL-1β, TNF-α, IL-4, IL-10, and TGF-β were evaluated by the quantitative reverse transcription-polymerase chain reaction. BHD treatment significantly reduced body weight and arteriosclerosis plaque area and blood lipid levels including total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C). Meanwhile, BHD demonstrated a significant suppression of M1 polarization, by decreased secretion of iNOS and pro-inflammatory factors (IL-6, IL-1β, and TNF-α) in ApoE-/- mice. The present study also revealed that BHD promotes the activation of M2 polarization, characterized by the expression of Arg-1 and anti-inflammatory factors (IL-4 and IL-10). In addition, PKM2/HIF-1α signaling was improved by M1/M2 macrophages polarization induced by BHD. The downstream target genes (GLUT1, LDHA, and PDK1) expression was significantly increased in high fat feeding ApoE-/- mice, and those of which were recused by BHD and Atorvastatin. These results suggested that M1/M2 macrophages polarization produce the inflammatory response against AS progress after BHD exposure.

The SGLT2 inhibitor Empagliflozin promotes post-stroke functional recovery in diabetic mice

Type-2 diabetes (T2D) worsens stroke recovery, amplifying post-stroke disabilities. Currently, there are no therapies targeting this important clinical problem. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are potent anti-diabetic drugs that also efficiently reduce cardiovascular death and heart failure. In addition, SGLT2i facilitate several processes implicated in stroke recovery. However, the potential efficacy of SGLT2i to improve stroke recovery in T2D has not been investigated. Therefore, we determined whether a post-stroke intervention with the SGLT2i Empagliflozin could improve stroke recovery in T2D mice. T2D was induced in C57BL6J mice by 8 months of high-fat diet feeding. Hereafter, animals were subjected to transient middle cerebral artery occlusion and treated with vehicle or the SGLTi Empagliflozin (10 mg/kg/day) starting from 3 days after stroke. A similar study in non diabetic mice was also conducted. Stroke recovery was assessed using the forepaw grip strength test. To identify potential mechanisms involved in the Empagliflozin-mediated effects, several metabolic parameters were assessed. Additionally, neuronal survival, neuroinflammation, neurogenesis and cerebral vascularization were analyzed using immunohistochemistry/quantitative microscopy. Empagliflozin significantly improved stroke recovery in T2D but not in non-diabetic mice. Improvement of functional recovery was associated with lowered glycemia, increased serum levels of fibroblast growth factor-21 (FGF-21), and the normalization of T2D-induced aberration of parenchymal pericyte density. The global T2D-epidemic and the fact that T2D is a major risk factor for stroke are drastically increasing the number of people in need of efficacious therapies to improve stroke recovery. Our data provide a strong incentive for the potential use of SGLT2i for the treatment of post-stroke sequelae in T2D.