Western Diet Research Articles

Noninvasive Monitoring of Steatotic Liver Disease in Western Diet‐Fed Obese Mice Using Automated Ultrasound and Shear Wave Elastography

ABSTRACTBackground and AimsUltrasound imaging and shear wave elastography (SWE) can be used to noninvasively stage hepatopathologies and are widespread in clinical practice. These techniques have recently been adapted for small animal use in a novel 3D in vivo imaging system capable of high‐throughput automated scanning. Our goal was to evaluate the feasibility of using this imaging tool in the murine Western diet (WD) model, a highly translatable preclinical model of obesity, metabolic disease and liver fibrosis.MethodsFemale C57BL/6 mice (N = 48) were placed on WD or chow diet and imaged longitudinally for a period of 48 weeks. Imaging consisted of 3D B‐mode and targeted SWE captures. Liver volume, liver echogenicity and liver stiffness were quantified from in vivo imaging data. A subset of mice was sacrificed at various timepoints (0, 12, 24 and 48 weeks) for histological workup. Correlation analysis was performed between in vivo imaging and histological measurements to determine level of agreement.ResultsNoninvasive imaging showed statistically significant increases in liver volume and echogenicity, but non‐significant increase in liver stiffness in the WD‐fed cohort, suggesting development of hepatomegaly and steatosis, but negligible fibrosis. Ex vivo analysis confirmed significant increases in liver weight, liver triglycerides and ALT, but limited increases in fibrosis corroborating noninvasive imaging results. Correlation analysis between imaging and histology demonstrated good agreement between liver volume/liver weight (R2 = 0.85) and echogenicity/triglycerides (R2 = 0.76).ConclusionsThis study demonstrated that noninvasive ultrasound liver assessments are feasible in the WD mouse model and closely reflect the underlying pathological state of the animal. Automated ultrasound can serve as a high‐throughput noninvasive screening method for preclinical liver disease research and drug development.

The role of inflammation induced by necroptosis in the development of fibrosis and liver cancer in novel knockin mouse models fed a western diet

The role of inflammation induced by necroptosis in the development of fibrosis and liver cancer in novel knockin mouse models fed a western diet

The Impact of Diet and Nutrition on Immune Function: Implications for Health and Disease

The relationship between diet, nutrition, and immune function is crucial for maintaining health and preventing disease. This review explores how key nutrients and dietary patterns influence immune responses, highlighting the role of vitamins, minerals, and macronutrients in supporting both innate and adaptive immunity. Micronutrients such as vitamins C, D, A, and minerals like zinc, selenium, and iron are essential for the production of immune cells, antibodies, and regulating inflammation. Macronutrients, including proteins and omega-3 fatty acids, contribute to the immune system by supporting the synthesis of immune cells and modulating inflammatory responses. Dietary patterns also significantly affect immune function. The Mediterranean diet, rich in antioxidants, healthy fats, and fiber, enhances immune regulation and reduces chronic inflammation, while the Western diet, characterized by high sugar, refined carbohydrates, and unhealthy fats, can suppress immune activity and promote inflammation, increasing susceptibility to infections and chronic diseases. Malnutrition, whether through undernutrition or overnutrition, impairs immune function, increasing vulnerability to infections and hindering recovery. Gut health, closely linked to nutrition, also plays a vital role in immune regulation through the gut microbiome. This review underscores the importance of a balanced, nutrient-rich diet in supporting optimal immune function and preventing disease, with implications for both individual health and broader public health strategies. Keywords: Immune function, Micronutrients, Dietary patterns, Chronic inflammation, Disease prevention

Western diet promotes endometriotic lesion growth in mice and induces depletion of Akkermansia muciniphila in intestinal microbiota.

Endometriosis, affecting 10% of women in their reproductive years, remains poorly understood. Both individual and environmental unexplained factors are implicated in this heterogenous condition. This study aims to examine the influence of a Western diet on endometriosis lesion development in mice and to uncover the mechanisms involved. Mice were fed either a control diet or a Western diet (high in fatty acids and low in fiber) for 4weeks. Endometriosis was then surgically induced, and lesion development was monitored by ultrasound. After 7weeks, the mice were sacrificed for analysis of lesion characteristics through RT-qPCR, immunohistochemistry, and flow cytometry. Additionally, the intestinal microbiota was assessed using 16S rRNA gene sequencing. Mice on the Western diet developed lesions that were significantly twice as large compared to those on the control diet. These lesions exhibited greater fibrosis and proliferation, alongside enhanced macrophage activity and leptin pathway expression. Changes in the intestinal microbiota were significantly noted after endometriosis induction, regardless of diet. Notably, mice on the Western diet with the most substantial lesions showed a loss of Akkermansia Muciniphila in their intestinal microbiota. A Western diet significantly exacerbates lesion size in a mouse model of endometriosis, accompanied by metabolic and immune alterations. The onset of endometriosis also leads to substantial shifts in intestinal microbiota, suggesting a potential link between diet, intestinal health, and endometriosis development.

Maternal Dietary Improvement or Leptin Supplementation During Suckling Mitigates the Long-Term Impact of Maternal Obesogenic Conditions on Inflammatory and Oxidative Stress Biomarkers in the Offspring of Diet-Induced Obese Rats

This study investigates the impact of maternal nutrition during lactation on inflammation and oxidative stress in the offspring of diet-induced obese rats, along with the potential benefits of leptin supplementation during suckling. Dams were fed either a standard diet (SD), a western diet (WD) before and during gestation and lactation (WD-dams), or a WD switched to an SD during lactation (Rev-dams). Offspring were supplemented with leptin or vehicle during suckling and then fed an SD or WD until four months. Offspring of the Rev-dams exhibited improved metabolic indicators, including lower body weight, reduced plasma levels of TNF-alpha, a higher adiponectin/leptin (A/L) ratio, enhanced liver antioxidant defenses, and decreased inflammation markers in white adipose tissue (WAT) compared to WD-dams, with sex differences. Leptin supplementation further modulated these markers, reducing oxidative stress in liver and inflammation in WAT and liver (e.g., hepatic Tnfa expression decreased by 45% (males) and 41% (females) in the WD group on an SD), and improving the A/L ratio, with effects varying by maternal conditions and sex. In conclusion, this study underscores the importance of maternal nutrition and leptin intake during suckling in shaping long-term metabolic and inflammatory health in offspring, offering strategies to mitigate the adverse effects of maternal obesity on future generations.

What Is the Role of the Gut Microbiota in Anastomotic Leakage After Colorectal Resection? A Scoping Review of Clinical and Experimental Studies

Background: Anastomotic leakage (AL) still remains a common complication after colorectal anastomosis that leads to increased morbidity and mortality. The gut microbiota has been hypothesized as one of the risk factors associated with anastomotic leakage. The aim of the present study was to summarize all existing clinical and experimental studies that evaluate the impact of intestinal microbiota on anastomotic leakage after colorectal resection. Methods: The present scoping review was designed according to PRISMA recommendations and a systematic search in Medline, Scopus, EMBASE, Clinicaltrials.gov, Google Scholar, and CENTRAL was conducted until September 2024. Results: Overall, 7 clinical and 5 experimental studies were included. A diminished α-diversity of the gut microbiota in patients suffering from AL was demonstrated. Specific microbe genera, such as Lachnospiraceae, Bacteroidaceae, Bifidobacterium, Acinetobacter, Fusobacterium, Dielma, Elusimicronium, Prevotella, and Faecalibacterium, seem to be associated with AL. However, specific genera, like Prevotella, Streptococcus, Eubacterium, Enterobacteriaceae, Klebsiella, Actinobacteria, Gordonibacter, Phocaeicola, and Ruminococcus2, seem to be protective against AL. Experimental studies highlighted that the Western diet seems to affect microbiota diversity and increases the AL rate, whereas anastomotic healing seems to be impaired by high metalloproteinase production and increased collagenase activity. Conclusions: The intestinal microbiota seems to play an important role in anastomotic leakage after colorectal resection. Specific interventions targeting the microbiota’s composition and the pathophysiological mechanisms by which it impairs anastomotic healing could diminish the risk for anastomotic leakage and improve clinical outcomes. However, future studies should be based on prospective design and eliminate heterogeneity.

Empirically Derived Dietary Patterns in Association with Asthma Symptoms in Children and Adolescents: A Cross-Sectional Study

Background: Limited data exists regarding the association between dietary patterns and asthma. This study aims to determine the relationship between empirically derived dietary patterns and the likelihood of asthma among a large population of children and adolescents living in central Iran. Methods: A total of 7667 of male and female students aged 6-14 from 48 public and private schools in YAZD urban areas entered the current cross-sectional study. Data on dietary intakes, as well as asthma symptoms and other possible confounders, were collected using a self-administered questionnaire filled by parents. Factor analysis was applied to find major dietary patterns. Multivariate logistic regression was performed to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) for asthma development across quintiles of dietary patterns. Results: Two main dietary patterns were established. A “traditional diet” was determined by meat, fish, fruits, cooked vegetable, raw vegetable, legumes, cereals, bread, macaroni, rice, margarine, butter, olive oil, milk, yogurt, egg, nuts, potato, and a “western-like diet” was characterized by high intakes of simple sugars, fast food(hamburger), fast food (pizza), soft drinks, jelly, chocolate and biscuits of cocoa, ice cream, and sauce. After adjusting for potential confounders, individuals in the top quintile of traditional diet were 0.31 times less likely to have asthma than those in the lowest quintile (OR=0.69; 95% CI: 0.47-1.00). Moreover, individuals in the top quintile of traditional diet were 0.43 times less likely to have wheezing compared with those in the lowest quintile (OR=0.57, 95% CI: 0.46-0.70). However, individuals in the top quintile of the western diet were 0.35 times more likely to have wheezing than those in the lowest quintile (OR=1.35, 95% CI: 1.10-1.66). Conclusions: According to the results, a traditional diet might be associated with lower odds of asthma; however, a western-like diet might be adversely associated with asthma symptoms.

Interplay Between Western Diet and Mammary Cancer: Data from a Chemically-induced Model in Wistar Rats.

This study aimed to investigate the influence of Western diet on mammary cancer in Wistar female rats, focusing on systemic responses and tumor development. Twenty-eight Wistar female rats were acclimatized and divided into four experimental groups (n=7 each): Western diet (WD), Western diet with N-methyl-N-nitrosourea (MNU) administration (WD+MNU), standard diet (CTR), and standard diet with MNU administration (CTR+MNU). MNU was administered intraperitoneally at 50 mg/kg at seven weeks of age to induce mammary cancer. The 20-week experiment involved monitoring animal weight, food and water intake. At the end of the study, rats were euthanized, and blood samples and organs were collected for hematological and plasma biochemical analysis, oxidative stress, and histo-pathological and immunobiological evaluations of the tumors. No significant differences were found in body weight, composition, or organ weights, but the WD group showed reduced food and water intake and lower cholesterol levels. Leptin and adiponectin levels were higher in the WD+MNU group, suggestive of changes in appetite regulation. Histopathological analysis showed malignant tumors in both MNU-induced groups. However, WD groups had fewer tumors compared to the CTR+MNU group. WD led to higher feed efficiency and increased visceral adipose tissue but decreased systemic cholesterol and triglyceride levels. While this diet resulted in lower tumor incidence, the volume and weight of the tumors were higher. Additionally, the WD decreased ERα and progesterone receptor immunoexpression, while Ki-67 immunoexpression was elevated.

The cAMP/PKA signaling pathway conditions cardiac performance in experimental animals with metabolic syndrome

Metabolic syndrome (MetS) increases the risk of coronary artery disease, but effects of this condition on the working myocardium remain to be fully elucidated. In the present study we evaluated the consequences of diet-induced metabolic disorders on cardiac function and myocyte performance using female mice fed with Western diet. Animals maintained on regular chow were used as control (Ctrl). Mice on the Western diet (WesD) had increased body weight, impaired glucose metabolism, preserved diastolic and systolic function, but increased left ventricular (LV) mass, with respect to Ctrl animals. Moreover, WesD mice had reduced heart rate variability (HRV), indicative of altered cardiac sympathovagal balance. Myocytes from WesD mice had increased volume, enhanced cell mechanics, and faster kinetics of contraction and relaxation. Moreover, levels of cAMP and protein kinase A (PKA) activity were enhanced in WesD myocytes, and interventions aimed at stabilizing cAMP/PKA abrogated functional differences between Ctrl and WesD cells. Interestingly, in vivo β-adrenergic receptor (β-AR) blockade normalized the mechanical properties of WesD myocytes and revealed defective cardiac function in WesD mice, with respect to Ctrl. Collectively, these results indicate that metabolic disorders induced by Western diet enhance the cAMP/PKA signaling pathway, a possible adaptation required to maintain cardiac function.

Extracellular matrix protein 1 binds to connective tissue growth factor against liver fibrosis and ductular reaction.

Extracellular matrix protein 1 (ECM1) can inhibit TGFβ activation, but its antifibrotic action remains largely unknown. This study aims to investigate ECM1 function and its physical interaction with the profibrotic connective tissue growth factor (CTGF) in fibrosis and ductular reaction (DR). Ecm1 knockouts or animals that ectopically expressed this gene were subjected to induction of liver fibrosis and DR by feeding 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) or α-naphthyl-isothiocyanate (ANIT). ECM1 and CTGF were also examined in the livers of patients with alcohol-associated liver disease (ALD) or ethanol-exposed animals that were fed the western diet for 4 months in the WDA model with liver pathology resembing ALD in patients. ECM1 bound to CTGF in yeast two-hybrid systems, cultured liver cells, and cholestatic livers damaged by DDC or α-naphthyl-isothiocyanate. This interaction blocked integrin αvβ6-mediated TGFβ activation, thereby reducing fibrotic responses in vitro. ECM1 downregulation was associated with biliary CTGF induction during human ALD progression. In experimental models, Ecm1 loss enhanced susceptibility to DDC-induced cholestasis with upregulation of Ctgf, αvβ6, alpha-smooth muscle actin, procollagen type I, serum transaminase, and total bilirubin levels in germline knockouts, whereas forced expression of this gene significantly attenuated DR and biliary fibrosis after the feeding of DDC or α-naphthyl-isothiocyanate containing diets. Moreover, ectopic Ecm1 inhibited not only alcohol-associated fibrosis but also TGFβ-mediated deregulation of hepatocyte nuclear factor 4α, preventing the production of the fetal p2 promoter-driven isoforms in the WDA model. We uncover a novel antifibrotic action by ECM1 that binds CTGF and inhibits integrin αvβ6-mediated TGFβ activation. Targeting its loss has therapeutic potential for the treatment of DR and liver fibrosis in chronic conditions, such as cholangiopathy and ALD.

Anthocyanin-rich lingonberry extract improves intestinal homeostasis based on intestinal stem cells in high-fat-diet-fed mice via gut microbiota-mediated Wnt/PPAR signaling

The Western diet impairs physiological health and leads to intestinal dysfunction. Lingonberries have the potential to ameliorate intestinal damage, although the underlying mechanisms are unclear. Here, the modulatory action of lingonberry anthocyanins on intestinal homeostasis in high-fat diet (HFD)-fed mice was investigated from the perspective of the intestinal flora-intestinal stem cells (ISCs) axis. The anthocyanin composition of lingonberry (Vaccinium vitis-idaea L.) extract was determined by high-performance liquid chromatography (HPLC). Anthocyanin-rich lingonberry extract (ARLE) was administered to HFD-fed mice for 9 weeks. Intestinal injury and ISCs fitness were analyzed by qPCR, immunofluorescence, and Western Blot. Moreover, the gut microbiota was analyzed by 16S rRNA sequencing and jejunum was used for RNA sequencing (RNA-Seq). The results showed that ARLE contained a total of 20 anthocyanins, which accounted for 36.0% of the extract. ARLE may balance intestinal homeostasis by enhancing the intestinal barrier and maintaining steady-state proliferation and differentiation of ISCs. RNA-seq revealed that ARLE supplementation improved the immune response and ISCs homeostasis by modulating Wnt/PPAR signaling, and this was potentially related to the gut microbiota. Our findings support that ARLE improved gut homeostasis and attenuated HFD-induced injury by regulating the gut microbiota-ISCs axis via Wnt/PPAR signaling.

The Impact of Macronutrient and Dietary Patterns on Gestational Diabetes Mellitus

Pregnancy is a physiological condition that increases insulin resistance (IR) due to hormonal changes, including elevated levels of estrogen, progesterone, and human placental lactogen (HPL). Such IR, especially in the later stages of pregnancy, can cause gestational diabetes mellitus (GDM), characterized by glucose intolerance first detected during pregnancy. GDM poses significant health risks for both the mother and the fetus, including the potential for pre-eclampsia, emergency C-sections, and type 2 diabetes (T2D) for the mother, as well as preterm birth, hypoglycemia, and being large for gestational age (LGA) for the baby. Proper dietary modifications can help regulate blood sugar levels, improve insulin sensitivity, and ensure healthy gestational weight gain (GWG), thereby reducing the possibility of undesirable outcomes. This paper discusses the role of energy, carbohydrate, fat, and protein, and compares the effects of the Mediterranean diet (MD) and Western diet (WD) on the risk of GDM. The main objective of this paper is to identify the most effective dietary strategies for preventing and managing GDM. The finding indicates that a MD rich in nutrient-dense foods, complex carbohydrates/lower GI, unsaturated fatty acids (FAs), and balanced protein has beneficial effects on GDM. In contrast, the WD with empty calories, simple carbohydrates/higher glycemic index (GI), saturated FAs (SFA), and animal-based protein increases the risk of GDM. Future studies should continue to explore the long-term effects of dietary interventions, integrate other lifestyle factors, and consider genetic differences to provide comprehensive management strategies for GDM.

Sexual Dimorphism in the Immunometabolic Role of Gpr183 in Mice

Abstract Aim Excessive eating and intake of a Western diet negatively affect the intestinal immune system, resulting in compromised glucose homeostasis and lower gut bacterial diversity. The G protein-coupled receptor GPR183 regulates immune cell migration and intestinal immune response and has been associated with tuberculosis, type 1 diabetes, and inflammatory bowel diseases. We hypothesized that with these implications, GPR183 has an important immunometabolic role and investigated this using a global Gpr183 knock-out mouse model. Material and methods Wild-type (WT) and Gpr183 deficient (Gpr183-/-) mice were fed a high-fat, high-sucrose diet (HFSD) for 15 weeks. We investigated changes in weight, body composition, fecal IgA levels, fecal microbiome, and glucose tolerance before and after the diet. Macrophage infiltration into visceral fat was determined by flow cytometry, and hepatic gene expression was measured. Results and conclusions A sexual dimorphism was discovered, where female Gpr183-/- mice showed adverse metabolic outcomes compared to WT counterparts with inferior glucose tolerance, lower fecal IgA levels, and increased macrophage infiltration in visceral fat. In contrast, male Gpr183-/- mice had significantly lower fasting blood glucose after diet than male WT mice. Liver gene expression showed reduced inflammation and macrophage markers in Gpr183-/- livers, regardless of sex, while the pancreatic islet area did not differ between the groups. No conclusive differences were found after microbiome sequencing. To conclude, Gpr183 maintains metabolic homeostasis in female but not in male mice independent of diet. If confirmed in humans, future therapy targeting GPR183 should consider this sexual dimorphism.

Investigating the effects of empagliflozin on myocardial metabolic and lipid profile in healthy and metabolic syndrome murine models following acute myocardial infarction

Abstract Background/Introduction Empagliflozin (EMPA) is a sodium/glucose co-transporter type 2 inhibitor with clinically documented cardioprotective effect. However, the mechanism of cardioprotection remains elusive. We have previously shown that Western diet induces metabolic syndrome (MS) and deteriorates cardiac function in mice, whereas EMPA treatment for 6 weeks prevents this damage. Also, EMPA administration for 6 weeks suppresses ischemia/reperfusion (I/R) injury in mice, independent of the presence of MS. Purpose The aim of the present study is to investigate whether changes in myocardial metabolic and lipid profile, induced by EMPA treatment, are responsible for its cardioprotective effect in the setting of myocardial I/R injury. Methods C57Bl6 mice received chow diet or Western diet for 14 weeks. At week 8, mice from each dietary group were randomized into 3 subgroups: 1. Control - Sham surgery (5% DMSO-SHAM), 2. Control - I/R (5% DMSO-I/R) and 3. EMPA (10mg/kg/day in 5% DMSO) - I/R (EMPA-I/R) and received the corresponding treatment by daily per os administration for 6 weeks. At week 14, mice were subjected to 30 minutes of I, followed by 2 hours of R, or sham surgery. Myocardial tissue was harvested at the end of R, and metabolomic and lipidomic analysis was performed by nuclear magnetic resonance spectroscopy and mass spectrometry, respectively. Body weight, as well as blood glucose and cholesterol levels were assessed at baseline and at the end of the administrations. Results EMPA administration reduced body weight, as well as blood glucose and cholesterol levels in animals with MS. EMPA decreased anaerobic glycolysis products (UDP-glucose, Lactic acid) and ketone bodies (β-hydroxybutyrate, acetoacetic acid) in both healthy animals and mice with MS. Additionally, an increase in ATP, accompanied by a decrease in AMP and ADP were observed in the EMPA-I/R group, compared to the DMSO-I/R group. Regarding the lipidomic analysis, gangliosides GM3 emerged as the major lipid group decreased by EMPA treatment. Lastly, despite significant changes were presented in the metabolic and lipid profile between healthy animals and those with MS, the effects of EMPA on myocardial metabolic and lipid profile were the same, regardless of the presence of MS. Conclusion(s) EMPA administration induces metabolic changes in the heart tissue and improves myocardial energetics upon myocardial I/R injury. Also, EMPA suppresses gangliosides GM3, a lipid group that has been associated with neutrophil activation and recruitment. Importantly, the effects of EMPA on myocardial metabolic and lipid profile following I/R is independent of the presence of MS.

Macrophage heterogeneity in cardiometabolic disease

Abstract Metabolic diseases such as obesity and atherosclerosis are characterised by chronic inflammation that leads to the accumulation of immune cells in affected organs. Macrophages in the obese adipose tissue and the atherosclerotic plaque show transcriptional, phenotypic and functional heterogeneity. The accumulation of CD11c+ macrophages in atherosclerosis and obesity suggests the presence of conserved macrophage phenotypes in metabolic tissues. We aimed to characterise shared and distinct features of monocytes and macrophages in the aorta and adipose tissue in the context of metabolic disease using single-cell techniques. Single-cell RNA sequencing of the blood, aorta and visceral adipose tissue during a time course of metabolic disease progression (steady state, 12w western diet, 18w western diet) and data integration with murine aortic and adipose tissue community datasets revealed conserved and tissue specific features of metabolic disease. Resident macrophages in the aorta and adipose tissue displayed tissue specific transcriptional programs, highlighting that cell maintenance and function of tissue resident macrophages differ between metabolic tissues. Further, macrophages in the aorta and adipose tissue undergo disease associated compositional changes. For example, we uncovered distinct CD11c+ macrophage subsets that are conserved in the aorta and adipose tissue across multiple metabolic disease models and share core transcriptional signatures between both metabolic tissues. However, CD11c+ macrophage subsets showed tissue specific dynamics during metabolic disease progression. Overall, our analysis underscores that tissue niche affects macrophage composition as well as activation and transcriptional regulation patterns. Understanding similarities and differences between the two tissues will be important to inform identification of new therapeutic targets for cardiometabolic diseases.

Cardioprotective potential of oleuropein, hydroxytyrosol, oleocanthal and their combination: unravelling complementary effects on acute myocardial infarction and metabolic syndrome

Abstract Background/Introduction Clinical studies have established the role of olive products in primary and secondary prevention of cardiovascular (CV) disease, but the single compounds or compound combinations responsible for the protective effects are still under investigation. Purpose We sought to explore and compare the cardioprotective potential of Oleuropein (OL), Hydroxytyrosol (HT), Oleocanthal (OC) and Oleanolic Acid (OA) and three combinational treatments after chronic oral administration in mice subjected to Ischemia/Reperfusion Injury (IRI) in the presence of metabolic syndrome (MS) and verify the effect of combination in a proof-of-concept clinical study in Chronic Coronary Artery Syndrome (CCAS) patients. Methods First, we explored the IRI-limiting potential of 6-weeks daily oral treatment with OL (20.6 mg/kg), HT (5.9 mg/kg), OC (11.6 mg/kg), OA (17.4 mg/kg) or vehicle (DMSO 5%) in healthy C57Bl6 mice. At week 6, myocardial ischemia/reperfusion (30 minutes/2 hours) was induced and infarct size was measured. Next, MS was established by 14 weeks of Western diet and the isolated compounds were administered for the last 6 weeks. At week 14, IRI was surgically induced, and infarct size was determined. Basic MS parameters (fasting blood glucose, plasma cholesterol, body weight and blood pressure) were recorded at baseline, weeks 8 and 14. According to the exerted benefits, three combinational treatments were designed and tested on the MS model of IRI. The underlying cardioprotective mechanism was investigated on the mixture with preponderant CV benefits (OL-HT-OC, Combo 2). ApoE-/- mice fed with Western diet for 12 weeks were treated with Combo 2 orally for the last 4 weeks and aortic atherosclerotic lesion extent was determined to detect possible antiatherosclerotic effects. After multi-organ toxicity evaluation, a Combo 2-based supplement was administered in CCAS patients for evaluation of cardiac function, inflammation and oxidative stress biomarkers. Results OL, OC and OA, but not HT, significantly reduced infarct size in vivo both in healthy and MS mice. OL was the only compound to reduce hyperglycemia, while OA significantly reduced plasma cholesterol. All mixtures (Combo 1: OL-HT-OA, Combo 2: OL-HT-OC, Combo 3: OL-HT-OC-OA) were cardioprotective, but only Combo 2 prevented MS progression by limiting hyperglycemia. Combo 2 protection against IRI was attributed to apoptosis suppression (reduced Bax/BcL-xL ratio) and increased expression of the antioxidant enzymes Superoxide Dismutase and Catalase in the ischemic myocardium. Combo 2 treatment also reduced atherosclerotic lesion extent. In our proof-of-concept clinical study, Combo 2 treatment ameliorated cardiac, vascular and endothelial function in CCAS patients. Conclusions Combinational treatment with OL-HT-OC exerts potent cardioprotective, antihyperglycemic and antiatherosclerotic properties in vivo, with remarkable and clinically translatable CV benefits in high-risk patients.

Macrophages overexpressing interleukin-10 target and prevent atherosclerosis: regression of plaque formation and reduction in necrotic core

Abstract Background Atherosclerosis, a slowly progressing inflammatory disease, is characterized by the presence of monocyte-derived macrophages. Interventions targeting the inflammatory characteristics of atherosclerosis hold promising potential. Although interleukin (IL)-10 is widely acknowledged for its anti-inflammatory effects, systemic administration of IL-10 has limitations due to its short half-life and significant systemic side effects. Purpose We aimed to investigate the effectiveness of an approach designed to overexpress IL-10 in macrophages and subsequently introduce these genetically modified cells into ApoE-/- mice to promote atherosclerosis regression. Methods We engineered RAW264.7 cells to overexpress IL-10 (referred to as IL-10M) using lentivirusvectors. The ApoE-/- mice were divided into two groups based on the timing of the intervention. The early intervention group (n = 45) received intravenous tail injections from the beginning of Western diet (WD) at six weeks old. The late intervention group (n = 45) started receiving injections at 16 weeks old, 2 months after being fed the WD. Both the early and late intervention group stopped receiving injections after 5 months of being fed the WD. Results The IL-10M exhibited robust IL-10 secretion, maintained phagocytic function, improved mitochondrial membrane potentials, reduced superoxide production and showed a tendency toward the M2 phenotype when exposed to inflammatory stimuli. IL-10M can selectively target plaques in ApoE-/- mice, and oil red staining of the entire aorta unequivocally demonstrated that intervention with IL-10M elicited a substantial reduction in plaque area. H&E staining revealed that mice treated with IL-10M in the early intervention group showed a significant reduction in the ratio of plaque area to lumen area. However, the late intervention group did not exhibit statistically significant differences. Notably, mice treated with IL-10M exhibited significantly smaller necrotic cores and reduction in matrix metalloproteinase 9 within the aortic plaques in both the early and late intervention groups. Additionally, the administration of IL-10M showed no obvious side effects. Conclusion We developed an anti-inflammatory protein delivery system based on engineered macrophages that can target atherosclerotic plaques and reduce the plaque area and necrotic core. This approach has a promising safety profile and has the potential to be a therapeutic strategy for the intervention of atherosclerosis.

Profiling the L-arginine/arginase 1 metabolism in early and advanced atherosclerosis

Abstract Background Atherosclerosis is a chronic inflammatory disease and the primary underlying cause of cardiovascular disease (CVD). Recently, intracellular metabolic pathways have been identified as master switches of immune cell function and thus seem promising targets for therapeutic interventions aimed at lowering inflammation and thereby atherogenesis. Decades of research have demonstrated the importance of the amino acid (AA) L-arginine (Arg) in CVD. Although most research has focused on endothelium-dependent effects of Arg by the nitric oxide synthase (NOS), Arg metabolism - mainly through its metabolizing enzyme arginase 1 (Arg1) - has also been shown to regulate immune cell responses independent of its endothelial functions. Despite these findings, the cell-specific contribution of Arg/Arg1 metabolism on atherogenesis is still largely unknown. Purpose Profiling the Arg metabolism in endothelial and immune cells to identify cell-specific changes during athero-progression. Methods To investigate Arg metabolism in atherogenesis, we fed apolipoprotein E deficient (Apoe-­/­-) mice a Western diet (WD) for 6 and 12 weeks. Chow diet-fed aged-matched Apoe-­/-­ mice were used as littermate controls and C57BL/6 mice as steady-state controls. Systemic and local Arg concentrations were measured by mass-spectrometry. Arg metabolism in organs was studied by qPCR. Arg1 expression in atherosclerotic lesions was examined by immunohistochemistry (IHC). To assess cell-specific expression of Arg-related enzymes, aortic leukocytes from WD-fed Apoe-­/-­ mice were subjected to CITE-seq analysis. The role of T cell Arg1 was determined by nor-NOHA inhibition in Jurkat cells. Results AA measurements showed that systemic Arg was reduced in early and advanced atherogenesis (p<0.02), and splenic Arg was reduced in advanced atherogenesis (p=0.006) compared with steady state. In advanced atherosclerosis, Arg1 was decreased in the liver but increased in the spleen and aorta, whereas Nos2 was increased in the liver and aorta compared with steady state. To identify the cell types driving these local changes, we performed IHC on atherosclerotic lesions. Arg1+ lesional macrophages accumulated in advanced compared to early lesions (p=0.03), whereas Arg1+ endothelial cells tended to decrease (p=0.2). Surprisingly, we also found an accumulation of Arg1+ CD4+ T cells in lesions and a further upward trend with athero-progression. CITE-seq confirmed a constitutive expression of Arg1 in lymphoid clusters. In vitro experiments with Jurkat cells showed that arginase inhibition suppressed T cell proliferation and promoted apoptosis and migration (all p<0.0001). Conclusion Our data indicate that Arg metabolism is strongly regulated during athero-progression and suggest a so far unknown role of T cell-intrinsic Arg/Arg1 metabolism in the disease. Murine atherosclerosis studies are now being performed to decipher the cell-specific contribution of Arg/Arg1 metabolism in atherosclerosis.

Myeloid Tgfbr1/2-deficiency leads to a pro-atherogenic environment in ApoE-/- mice

Abstract Background Transforming growth factor beta (TGFβ) and its receptors (TGFβRs) are widely expressed by most human and murine cells and are implicated in several physiological and pathological conditions. In the context of atherosclerosis, TGFβ has been identified as a pleiotropic molecule involved in both pro- and anti-atherogenic processes, with its effects varying depending on the cell type it signals through. Purpose Given that myeloid cells play a major role in atherogenesis, we sought out to unravel the involvement of myeloid TGFβ signaling in atherosclerosis. Methods Aortic leukocytes from ApoE-/- mice fed a Western diet (WD) for 20 weeks were subjected to CITE-Seq analysis to assess the expression profile of Tgfβ and Tgfβrs. To investigate the effect of myeloid Tgfβ signaling on atherosclerosis, LysMCre+Tgfβr1flox/floxTgfβr2flox/floxmT/mGflox/floxApoE-/- (M-Tgfβr1/2dkoApoE-/-) mice and their LysMCre- littermates (ApoE-/-) were fed a WD for 6 weeks. Leukocyte phenotyping was assessed by flow cytometry (FC) and qPCR. Atherosclerotic plaque size in the aortic root was assessed by immunohistochemistry. Results CITE-Seq revealed that aortic ApoE-/- leukocytes highly expressed Tgfb1, whereas Tgfb2 and Tgfb3 were very lowly expressed. Tgfbr1 was mainly expressed in myeloid cells with macrophages and neutrophils showing the highest expression. Tgfbr2 was primarily expressed in T and B cells, while still showing a high level of expression in macrophages. Importantly, Tgfbr3 was not expressed in myeloid cells. Thus, to study the effect of myeloid Tgfβ signaling on atherosclerosis and to mitigate the potential for aberrant signaling that might arise from deleting only one receptor, we generated ApoE-/- mice with myeloid lineage tracing mT/mG alleles and combined deletion of Tgfbr1 and Tgfbr2 in myeloid cells using the LysMCre model. FC analysis of eGFP+ cells, i.e., cells where LysMCre is active, revealed a ~60-80% Tgfbr1/2 deletion efficiency in bone marrow-derived macrophages (BMDM) and in blood, splenic and BM CD11b+ cells, which was accompanied by decreased Smad2/3 signaling. M-Tgfβr1/2dkoApoE-/- mice showed a ~35% increase in blood and splenic CD11b+ cells and a ~25% increase in splenic macrophages compared to ApoE-/- controls, while BM CD11b+ cells were not affected. Tgfbr1/2-deficient BMDMs had increased Il-6, Il-1b and CD38 expression compared to controls, suggesting that Tgfbr1/2-deficient macrophages have acquired a pro-inflammatory phenotype. Interestingly, M-Tgfβr1/2dkoApoE-/- mice had ~30% fewer blood and splenic T cells compared to controls, which was explained by decreased naïve CD4+ and CD8+ T cells. M-Tgfβr1/2dkoApoE-/- mice had a ~50% increase in atherosclerotic plaque burden compared to ApoE-/- controls. Conclusion Our data suggest that impaired myeloid Tgfβ signaling leads to a pro-atherogenic environment in ApoE-/- mice. These effects may be mediated by an altered crosstalk between T cells and Tgfβr1/2-deficient macrophages.

LncRNA MEG3 promotes aortic valve calcification by inducing osteoblast differentiation via Wnt catenin signaling pathway

Abstract Background Calcific aortic valve stenosis (CAVS) is the most common valvular heart disease in elderly population. This study aimed to investigate the role of long non-coding RNAs (lncRNAs) in the development of CAVS. Methods ldlr-/-mice were feeding with western diet for 6 months to induce CAVS. RNA-seq analysis was performed to identify differentially expressed molecular signaling between aortic valves of CAVS mice and control mice. The degree of aortic stenosis was detected by ultrasound. Calcium salt deposits were detected by Haematoxylin and eosin (H&E) staining, Von Kossa staining and alizarin red S staining. PCR and western blotting were employed to detect osteogenic differentiation markers after various interventions. Results A mouse CAVS model was successfully established, as evidenced by increased thickness and calcium deposition in the aortic valve leaflets and increased transvalvular peak jet velocity. RNA-seq analysis showed that lncRNA MEG3 was significantly enriched in aortic valves of CAVS mice as compared to that of control mice. MEG3 expression in aortic valve, assessed by RNA in situ hybridization and PCR, was also significantly upregulated during the osteoblast differentiation of AVICs in vitro. Gain- and loss-of-function experiments indicate that MEG3 could indeed promote osteoblast differentiation of primary AVICs as evidenced by increased calcified nodule formation and expressions of osteoblast differentiation markers (Runx2 and osterix). Consistent with these in vitro data, MEG3 knockdown in vivo through tail injection of antisense oligonucleotide chain MEG3 (ASO-MEG3) at 6 weeks interval for 12 weeks significantly attenuated aortic valve calcification in CAVS mice. Subsequent KEGG analysis demonstrated that the Wnt/β-catenin signaling pathway was significantly enriched during the CAVS progression. Overexpression of MEG3 activated the Wnt/β-catenin signaling pathway and upregulated osteogenic protein expressions, while this upregulation could be significantly ameliorated by Dickkopf 1, a Wnt/β-catenin pathway inhibitor. Conclusion Present study demonstrates that LncRNA MEG3 could promote aortic valve calcification by inducing osteoblast differentiation via activating Wnt/β-catenin signaling pathway. Our results provide experimental evidence of targeting MEG3 and Wnt/β-catenin signaling pathway as potential promising therapeutic option for prevention and treatment of aortic valve calcification.