High Cholesterol Diet Research Articles

Gut microbiota response to consumption of milks fermented with specific strains of Lactococcus lactis with hypocholesterolemic effect

The alteration of structure and function of gut microbiota (dysbiosis) appears to be a major factor associated with metabolic disorders such as dyslipidemia and subsequent development of cardiovascular diseases. However, the consumption of fermented milks is a promising strategy to enhance health and restore the function of gut microbiota; specifically, in individuals with intestinal dysbiosis and hypercholesterolemia. Therefore, the aim of the present study was to evaluate the potential association between gut microbiota and the hypocholesterolemic effect of fermented milks with Lactococcus lactis NRRL B-571 (FM-571), NRRL B-572 (FM-572) and NRRL B-600 (FM-600) in Sprague–Dawley rats. Fermented milks were administered to hypercholesterolemic Sprague–Dawley rats during seven weeks. At the end of the experimental period, fecal and colonic microbiota were characterized using 16S RNA gene sequencing. Also, the short chain fatty acids (SCFAs) content was quantified in feces. Results showed that a high-cholesterol diet (HCD) altered the bacterial community in both fecal and mucosal samples. The consumption of fermented milks, specifically FM-572 promoted changes in the structure (beta diversity) in fecal, but not in mucosal microbiota. The levels of SCFAs in feces were improved after fermented milks consumption. From all SCFAs, butyrate was negatively correlated with total cholesterol, LDL-C (p < 0.05) and positively correlated with HDL-C (p < 0.05). Furthermore, Ruminococcaceae, Lactobacillaceae, Lachnospiraceae and Oscillospiraceae families, were negatively associated with total cholesterol, LDL-C (p < 0.05) and positively associated with HDL-C (p < 0.05). The abundance of these families was increased in groups treated with fermented milks, particularly with FM-572 (p < 0.05). Thus, the in vivo hypocholesterolemic effect after the consumption of milks fermented with Lactococcus lactis strains may be related with the modulation of fecal microbiota associated with the increase of butyrate-producing bacteria. Furthermore, these associations may suggest that butyrate may influence the cholesterol metabolism, resulting in the decreasing cholesterol levels.Graphical

Enavogliflozin, an sglt2 inhibitor, improves nonalcoholic steatohepatitis induced by high-fat high-cholesterol diet

Enavogliflozin, an sglt2 inhibitor, improves nonalcoholic steatohepatitis induced by high-fat high-cholesterol diet

Novel Role of Irbesartan in Elevating Serum High Density Lipoprotein in Hypercholesterolemic Animal Model

Objective: To explore the HDL cholesterol-raising capacity of Irbesartan (an antihypertensive drug) in rabbit'sserum.Study Design: Laboratory-based experimental study.Place and Duration of Study: The study was carried out at the Animal House of the National Institute of Health(NIH) Islamabad, Pakistan from January 2023 to November 2023.Methods: This study was conducted on 18 rabbits divided into three groups with six rabbits in each. Leaving one group as a normal control, two out of three groups were made hypercholesterolemic by a high-cholesterol diet. Irbesartan was given to one of the hypercholesteremic groups for 30 days. Blood samples were taken for serum analysis of HDL cholesterol.Results: Results of blood serum levels of all three groups were compared and analyzed on three differentoccasions i.e., on day zero, day 120, and day 150 for HDL cholesterol. Their means were calculated using SPSSVersion 20. The irbesartan-treated group showed obvious elevation in serum HDL cholesterol in comparisonwith the hypercholesteremic control group.Conclusion: It is concluded that Irbesartan, an antihypertensive drug has an additional role of elevating serumhigh-density lipoproteins and can provide the supplementary benefit of improving the lipid profile inhypertension and Hypercholesterolemia. How to cite this: Shakir S, Chaudhry ZR, Atif M, Sadaf R, Chaudhry ER, Chaudhry SR. Novel Role of Irbesartan in Elevating Serum High Density Lipoprotein in Hypercholesterolemic Animal Model. Life and Science. 2024; 5(2): 199-203. doi: http://doi.org/10.37185/LnS.1.1.536

IL-1β Inhibition Partially Negates the Beneficial Effects of Diet-Induced Atherosclerosis Regression in Mice.

Thromboembolic events secondary to rupture or erosion of advanced atherosclerotic lesions is the global leading cause of death. The most common and effective means to reduce these major adverse cardiovascular events, including myocardial infarction and stroke, is aggressive lipid lowering via a combination of drugs and dietary modifications. However, we know little regarding the effects of reducing dietary lipids on the composition and stability of advanced atherosclerotic lesions, the mechanisms that regulate these processes, and what therapeutic approaches might augment the benefits of lipid lowering. Smooth muscle cell lineage-tracing Apoe-/- mice were fed a high-cholesterol Western diet for 18 weeks and then a zero-cholesterol standard laboratory diet for 12 weeks before treating them with an IL (interleukin)-1β or control antibody for 8 weeks. We assessed lesion size and remodeling indices, as well as the cellular composition of aortic and brachiocephalic artery lesions, indices of plaque stability, overall plaque burden, and phenotypic transitions of smooth muscle cell and other lesion cells by smooth muscle cell lineage tracing combined with single-cell RNA sequencing, cytometry by time-of-flight, and immunostaining plus high-resolution confocal microscopic z-stack analysis. Lipid lowering by switching Apoe-/- mice from a Western diet to a standard laboratory diet reduced LDL cholesterol levels by 70% and resulted in multiple beneficial effects including reduced overall aortic plaque burden, as well as reduced intraplaque hemorrhage and necrotic core area. However, contrary to expectations, IL-1β antibody treatment after diet-induced reductions in lipids resulted in multiple detrimental changes including increased plaque burden and brachiocephalic artery lesion size, as well as increasedintraplaque hemorrhage, necrotic core area, and senescence as compared with IgG control antibody-treated mice. Furthermore, IL-1β antibody treatment upregulated neutrophil degranulation pathways but downregulated smooth muscle cell extracellular matrix pathways likely important for the protective fibrous cap. Taken together, IL-1β appears to be required for the maintenance of standard laboratory diet-induced reductions in plaque burden and increases in multiple indices of plaque stability.

Abstract 1047: Cerebral Cavernous Malformation 2 Knockout Hinders Murine Atherosclerosis And Lowers Vascular Inflammation

Introduction: Genome-wide association studies (GWAS) have identified &gt;300 loci associated with coronary artery disease (CAD). The chr7p13 locus harbors several variants associated with decreased CAD risk, which are within the exon or the potential regulatory element of cerebral cavernous malformation 2 (CCM2, odds ratio = 0.95, p=1.53e-08). While CCM2 has been studied in venous endothelial cells (ECs) in the context of cerebral cavernous malformation, the role of CCM2 in aortic ECs and coronary atherosclerosis remains unknown. Methods and Results: To test whether CCM2 regulates atherosclerosis development, CCM2 heterozygous knockout (CCM2 +/-) mice and their control littermates (CCM2 +/+) were injected with AAV-PCKS9-D377Y and subjected to a high-fat, high cholesterol diet for 12 weeks. Atherosclerotic lesions were quantified at three different aortic sites (aortic root, minor aortic arch, and the brachiocephalic artery). Notably, heterozygous CCM2 knockout mice exhibited reduced atherosclerosis lesion in the aortic root in male mice (p=0.03), but not in female mice. Next, we sought to understand the mechanism by which CCM2 regulates the development of atherosclerosis. Single cell RNA-seq was conducted using aorta from CCM2 +/- mice and CCM2 +/+ mice. Gene set enrichment analysis on the EC population suggested that CCM2 heterozygous knockout suppressed inflammation pathways especially the TNF-alpha signaling pathway. Concordantly, after 12-weeks of high-fat, high cholesterol diet, the number of monocytes in the aorta were decreased in CCM2 +/- mice when compared to CCM2 +/+ mice. Furthermore, in vitro, ECs lacking CCM2 showed impaired THP-1 monocyte adhesion (p=0.001) and decreased expression of MCP-1 (p=3e-4). Conclusions: Our findings suggest that CCM2 heterozygous knockout hinders the development of atherosclerosis. This is likely achieved by lowering MCP-1 expression and decreasing monocyte recruitment. Further investigations are being conducted to functionally identify the causal variant in the CCM2 locus, specifically under disease-relevant stimuli, to further our understanding of CCM2’s potential as a diagnostic and therapeutic target in CAD.

Excessive Hypercholesterolemia in Pregnancy Impairs Later-life Maternal Vascular Function in Rats

Background: Preeclampsia is a significant risk factor for the development of later-life cardiovascular disease; however, the underlying molecular mechanisms are not fully understood. Studies have shown that excessive hypercholesteremia occurring during pregnancy increases the risk of vascular pregnancy complications, such as preeclampsia. Bioavailability of nitric oxide (NO), a critical endothelium-derived vasodilator in pregnancy, is reduced in both hypercholesteremia and preeclampsia. However, the later-life vascular impact of excessive pregnancy-specific hypercholesteremia is not known. Hypothesis: Excessive hypercholesteremia in pregnancy impairs later-life maternal vascular function by reducing NO availability. Methods: Sprague-Dawley rats were fed a control diet (CD) or high cholesterol diet (HCD; 2% cholesterol + 0.5% cholic acid) from gestational day 6 to 20 (term=22 days; n=10-12). After pregnancy, all dams received a CD. Three months after pregnancy (equal to ~10 years in humans), mesenteric (systemic resistance arteries) and carotid (vascular bed that supplies blood to the cerebral vasculature) arteries were isolated, and endothelium-dependent (to methacholine, MCh) and -independent (to sodium nitroprusside, SNP) vasodilation, plus vasoconstriction responses (to phenylephrine, PE) were assessed using wire myography. NO contribution was assessed using a pan-NO synthase inhibitor (L-NAME; 100 μmol). Data were summarized as maximum responses (Emax), sensitivity (pEC50), or delta Emax (control vs. L-NAME). The statistical tests applied were a Student’s t-test or two-way ANOVA with Sidak’s post-hoc test (significance: p&lt;0.05). Results: In mesenteric arteries, vasodilation to MCh or SNP was not different between the CD and HCD groups three months after the insult. However, L-NAME reduced maximum vasodilation to MCh in the HCD group (p=0.0433) but not in CD animals. Similarly, vasoconstriction to PE was not different between groups, but L-NAME increased the PE sensitivity in the HCD group (p=0.0423), without effects in the CD animals. In carotid arteries, a HCD during pregnancy reduced vasodilation to MCh (p=0.0345), and while L-NAME prevented vasodilation to MCh in both groups (p&lt;0.0001), this effect was more pronounced in the HCD compared to CD group (delta Emax, p=0.0422). Vasodilation to SNP was similar between groups. Vasoconstriction responses to PE were increased in carotid arteries of HCD compared to CD animals (p=0.0357). L-NAME increased PE-mediated vasoconstriction in both groups (CD: 4.32-fold and HCD: 2.71-fold), but this NO modulation was significantly less in the HCD group compared to CD (delta Emax, p=0.0337). Conclusion: Exposure to a HCD, during pregnancy only, impaired later-life maternal vascular function in carotid, but not mesenteric arteries, suggesting vascular-bed specific effects in animals with a history of preeclampsia. Moreover, a HCD during pregnancy altered the NO pathway in both vascular beds, indicating that long-term alterations in NO were established during pregnancy. In summary, excessive pregnancy-specific hypercholesterolemia contributes to later-life maternal vascular dysfunction via modulation of the NO pathway, which may help explain the increased cardiovascular risk after preeclampsia. This work was supported by a foundation grant from the Canadian Institutes of Health Research (CIHR FS154313) and by the Women and Children’s Health Research Institute (WCHRI) through the generosity of the Stollery Children’s Hospital Foundation and the Alberta Women’s Health Foundation. A.A.O. is supported by a WCHRI postdoctoral fellowship through the generosity of the Stollery Children’s Hospital Foundation and the Alberta Women’s Health Foundation. E.E. was supported by a summer research studentship from Alberta Innovates. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Abstract 2064: Identifying A Novel Protein Protecting Against Atherosclerosis And Vascular Dysfunction

Atherosclerosis and ischemic heart disease are the leading causes of death in the US. The onset of atherosclerosis begins with endothelial dysfunction and ultimately progresses to occlusive plaques by mechanisms that are still incompletely understood. The basic mechanisms of atherosclerosis involve lipid accumulation and immune activation in the vascular wall. These processes are highly regulated, poorly understood, and lead to inflammation and atherosclerotic plaques in the arterial wall. We recently identified that Fat-Specific Protein 27 (FSP27) plays an important role in regulating vascular function. Using both clinical approaches that involved human biospecimens and “humanized” murine models of endothelium-specific FSP27-overexpressing transgenic (E-FSP27tg) mice, we demonstrated that FSP27 protects against high-fat diet (HFD)-induced dyslipidemia, endothelial dysfunction, and vasomotor impairment. We next hypothesized that FSP27 plays a critical role in protecting against atherosclerosis primarily via its action on endothelial cells. To test our hypothesis, we generated an innovative mouse model expressing the human FSP27 transgene specifically in the vascular endothelial cells of atherosclerosis-prone Apoe -/- mice, Apoe -/- -E-FSP27tg. Our preliminary data show that high-fat-high-cholesterol fed Apoe -/- -E-FSP27tg mice are strongly protected against plaque formation in numerous vascular territories including carotids and aorta upon feeding high-fat, high-cholesterol diets. Mechanistically, we found that FSP27 protects against oxidative stress and inflammation in the endothelial cells. Overall, our study discovered the novel beneficial cardiovascular effects of FSP27 where it protects against the development of vascular dysfunction, inflammation, and atherosclerosis.

Abstract 2010: Atherosclerotic Plaque Macrophages Drive Abdominal Aortic Aneurysm Formation

Introduction: Cigarette smoking (CS) contributes to the most deaths in abdominal aortic aneurysms (AAA) and tobacco use associates with early damage to the abdominal aorta. Associated risk factors, such as hyperlipidemia, link clinical AAA to the atherosclerotic process, suggesting common pathogenetic features with plaque development. We hypothesized that CS exposure exacerbates atherosclerotic disease in the abdominal aorta by increasing the recruitment of inflammatory macrophages that mediate arterial degradation and AAA formation. Methods: Adult male Apoe deficient mice commenced a high cholesterol diet and were concomitantly exposed to CS or room air (RA) for 4, 8, 12, and 16 weeks. As plaque macrophages are highly prevalent in advanced AAA, additional CS exposed mice received a selective CSF1R inhibitor, PLX3397, for up to 16 weeks to deplete macrophages. AAA incidence, atherosclerotic plaque burden and lesion composition were assessed in the aorta by immunofluorescence, Movat, EVG, and Oil Red O staining. Results: CS induced AAA at all timepoints with the highest incidence of 37% at 16 weeks of exposure (n=151 CS, n=75 RA p&lt; 0.05). Aneurysms always coincided with atherosclerosis (n=7 CS, n=7 CS/AAA p&lt;0.05), and severe elastin fragmentation was consistently overlaid by plaque (n=20 CS p&lt;0.05, Fig 1A and B). In some cases, lesions also associated with aortic rupture, causing death in ~11% of animals (n = 35 RA, n = 46 CS p&lt;0.04). CD68+ macrophages associated highly with severe elastin damage but less at intact regions (2.6-fold p&lt;0.0001, Fig 1C). PLX3397-mediated macrophage depletion attenuated plaque development and prevented AAA (n=20 treated, n=27 control p&lt;0.05, Fig 1D). Conclusion: CS exacerbates atherosclerosis and increases the accumulation of macrophages at sites of arterial injury. Depletion of macrophages results in a lack of aneurysm formation, highlighting their capacity to directly injure the aortic wall and necessity to mediate AAA.

Abstract 1041: Loss Of The ETS Transcription Factor ERG Disrupts Fate-defining Programs In The Aortic Endothelium And Promotes Expansion Of Endothelial Lineage Cells In Atherosclerotic Plaque

Aim: The ETS transcription factor ERG has been identified as a principal regulator of endothelial function through its ability to repress inflammation in endothelial cells (ECs), and loss of ERG induces endothelial to mesenchymal transition (EndMT) in fibrotic disease. To investigate ERG function in atherosclerosis, we employed an EC-specific Erg knockout ( Erg EC - KO ) in PCSK9-overexpression and apoE-deficient murine atherosclerosis models. Methods: Atherosclerosis was induced in 10-week-old Erg EC - KO mice or wild-type counterparts that had a Cre-inducible EC lineage tag ( Cdh5 CreER ; R26-CAG-LSL-Sun1-sfGFP ). Atherosclerosis was modeled by Apoe deletion or AAV8-PCSK9 with 12 weeks of high-cholesterol diet (1.25%). Aortic intimal cells were assessed with flow cytometry. Plaque burden, morphology, and cellularity were characterized with brightfield, Oil Red O, H&amp;E, Movat, and immunofluorescence imaging. Results: Erg EC-KO in PCSK9-overexpression mice led to a 1.6-fold increase in aortic plaque burden and plaque formation in regions that are usually protected (e.g., greater curvature; p≤0.03; n=9-10). Loss of ERG increased elastin breaks (1.7-fold; p=0.02; n=9) and decreased fibrous cap thickness (0.76-fold; p=0.02; n=9-10) in aortic arch cross sections. Aortic intimal digests from Erg EC- KO mice contained increased Sun1-sfGFP + EC lineage cells (1.9-fold; p=0.01; n=4), which had reduced CD31 positivity (0.79-fold; p=0.03; n=4). Notably, a 5.3-fold increase in EC lineage cells was observed in plaques from brachiocephalic artery cross sections (p=0.0001; n=6-15), which had hallmarks of EndMT (e.g., 31.5-fold increase in GFP + ACTA2 + cells, p=0.02, n=3-5). Increased aortic plaque burden was recapitulated in apoE-deficient E rg EC- KO mice (2.1-fold; p=0.02; n=4-8). Conclusion: Endothelial Erg KO results in increased plaque burden and altered plaque topography in murine atherosclerosis. Loss of ERG induces EndMT and marked ingression of ECs from the luminal endothelium to the plaque interior. These findings highlight loss of ERG as a novel mechanism by which intimal ECs acquire mesenchymal identity in atherosclerosis and implicate EC identity loss as a driver of EC migration into plaques, which is associated with a vulnerable morphology.

Naoxintong capsule remodels gut microbiota and ameliorates early-stage atherosclerosis in apolipoprotein E-deficient mice

BackgroundNaoxintong capsule (NXT) is a compound traditional Chinese medicine prescription with demonstrated effect for the treatment of cardiovascular and cerebrovascular diseases including atherosclerosis (AS). However, the pharmacological mechanisms of NXT in ameliorating early-stage AS are still unclear, especially regarding the role of gut microbiota. PurposeThis study is aiming to evaluate the therapeutic effect of NXT against early-stage AS, and further illustrate the potential correlations among AS, gut microbiota, and NXT. MethodsThirty-two male ApoE knockout mice (C57BL/6 background) were fed with a high cholesterol diet (HCD) for 4 weeks to establish an early-stage AS model. NXT in two different dosages and simvastatin (Simv) were than administrated for another 8 weeks. Lipid metabolism indicators and inflammation levels were measured with corresponding assay kits. Changes in blood vessels, liver lesions, and intestinal barrier proteins were evaluated with different staining methods. Furthermore, the gut microbiota structure was analyzed using 16S rRNA sequencing technology, while GC–MS was utilized to determine the fecal contents of short-chain fatty acids (SCFAs). ResultsAdministration of NXT significantly ameliorated obesity, hyperlipidemia, systemic inflammation, vasculopathy, liver injury, and intestinal barrier disorder in AS mice. Administration of NXT also significantly regulated the gut microbiota disturbance and increased the total contents of fecal SCFAs in AS mice. Furthermore, acetic acid content and the relative abundance of Faecalibacterium in feces were proposed as potential therapeutic biomarkers of NXT for AS treatment as indicated via the correlation analysis. ConclusionThis study demonstrated that NXT could effectively treat early-stage AS induced by HCD in mice. NXT regulated the gut microbiota and metabolites, maintained intestinal homeostasis, and improved the systemic inflammatory response. These findings may provide robust experimental support for the clinical use of NXT for AS treatment.

Neutrophil activation at high-fat high-cholesterol and high-fructose diets induces low-grade inflammation in mice

Nonalcoholic fatty liver disease (NAFLD), which can progress to nonalcoholic steatohepatitis (NASH), is a significant health concern affecting a substantial portion of the population. This study investigates the role of neutrophil extracellular traps (NETs) in liver inflammation induced by high-fat high-cholesterol diet (HFHCD) and high-fructose diet (HFD). The chronic nature of NAFLD involves low-grade inflammation with cytokine elevation. The research aims to visualize neutrophil elastase (NE) activity during HFHCD and HFD representing conditions of low-grade activation and assess neutrophil functional status. The study employs a mouse model subjecting animals to HFHCD, HFD or a standard diet (SD) for six weeks. Various analyses were used including histological evaluations, in vivo imaging of NE activity using a fluorescent probe, fluorescent microscopy, flow cytometry and assessment of neutrophil function through reactive oxygen species (ROS) levels. Mice on HFHCD and HFD display liver damage consistent with NASH, which was validated pathohistologically. NE activity in blood significantly increases after six weeks indicating systemic NETs involvement. In vivo imaging confirms NE activity in multiple organs. Cellular localization reveals NETs persistence even after neutrophil destruction in splenocytes indicating systemic involvement. Neutrophils under HFHCD exhibit a functional phenotype associated with low-grade inflammation, higher basal ROS levels and reduced activation potential. This study establishes the systemic impact of NETs in HFHCD- and HFD-induced liver inflammation, providing insights into the functional state of neutrophils. The findings contribute to understanding the mechanisms underlying chronic liver conditions and may inform future therapeutic strategies. Keywords: high fat diet, in vivo imaging, low-grade inflammation, NASH, neutrophil elastase, neutrophil extracellular traps, neutrophils

The Effect of Barley Bran Polyphenol-Rich Extracts on the Development of Nonalcoholic Steatohepatitis in Sprague–Dawley Rats Fed a High-Fat and High-Cholesterol Diet

Oxidative stress and inflammation play a central role in the progression of nonalcoholic steatohepatitis (NASH), which can lead to liver cirrhosis. Barley bran has potential bioactivities due to its high content of functional substances, such as anthocyanins, with anti-inflammatory and anti-oxidative properties. Here, we investigated whether barley bran polyphenol-rich extracts (BP) can prevent NASH in Sprague–Dawley rats fed a high-fat and high-cholesterol diet including 1.25% or 2.5% cholesterol for 9 weeks. In the rat model of NASH with advanced hepatic fibrosis, BP prevented NASH development by ameliorating the histopathological findings of lobular inflammation. The BP also tended to attenuate serum aspartate aminotransferase level in this model. In the rat model of NASH with mild-to-moderate hepatic fibrosis, BP tended to attenuate the serum levels of transaminases. BP-dose-dependent effects were revealed for several parameters, including monocyte chemoattractant protein-1, transforming growth factor-β, and manganese superoxide dismutase gene expressions in the liver. These results suggest that BP may prevent NASH development or progression, presumably due to its anti-inflammatory and anti-oxidative properties.

A high-cholesterol diet promotes the intravasation of breast tumor cells through an LDL–LDLR axis

Most metastases in breast cancer occur via the dissemination of tumor cells through the bloodstream. How tumor cells enter the blood (intravasation) is, however, a poorly understood mechanism at the cellular and molecular levels. Particularly uncharacterized is how intravasation is affected by systemic nutrients. High levels of systemic LDL-cholesterol have been shown to contribute to breast cancer progression and metastasis in various models, but the cellular and molecular mechanisms involved are still undisclosed. Here we show that a high- cholesterol diet promotes intravasation in two mouse models of breast cancer and that this could be reverted by blocking LDL binding to LDLR in tumor cells. Moreover, we show that LDL promotes vascular invasion in vitro and the intercalation of tumor cells with endothelial cells, a phenotypic change resembling vascular mimicry (VM). At the molecular level, LDL increases the expression of SERPINE2, previously shown to be required for both VM and intravasation. Overall, our manuscript unravels novel mechanisms by which systemic hypercholesterolemia may affect the onset of metastatic breast cancer by favouring phenotypic changes in breast cancer cells and increasing intravasation.

L-carnitine and Ginkgo biloba Supplementation In Vivo Ameliorates HCD-Induced Steatohepatitis and Dyslipidemia by Regulating Hepatic Metabolism.

Treatment strategies for steatohepatitis are of special interest given the high prevalence of obesity and fatty liver disease worldwide. This study aimed to investigate the potential therapeutic mechanism of L-carnitine (LC) and Ginkgo biloba leaf extract (GB) supplementation in ameliorating the adverse effects of hyperlipidemia and hepatosteatosis induced by a high-cholesterol diet (HCD) in an animal model. The study involved 50 rats divided into five groups, including a control group, a group receiving only an HCD, and three groups receiving an HCD along with either LC (300 mg LC/kg bw), GB (100 mg GB/kg bw), or both. After eight weeks, various parameters related to lipid and glucose metabolism, antioxidant capacity, histopathology, immune reactivity, and liver ultrastructure were measured. LC + GB supplementation reduced serum total cholesterol, triglyceride, low-density lipoprotein cholesterol, glucose, insulin, HOMA-IR, alanine transaminase, and aspartate transaminase levels and increased high-density lipoprotein cholesterol levels compared with those in the HCD group. Additionally, treatment with both supplements improved antioxidant ability and reduced lipid peroxidation. The histological examination confirmed that the combination therapy reduced liver steatosis and fibrosis while also improving the appearance of cell organelles in the ultrastructural hepatocytes. Finally, the immunohistochemical analysis indicated that cotreatment with LC + GB upregulated the immune expression of GLP-1 and β-Cat in liver sections that were similar to those of the control animals. Mono-treatment with LC or GB alone substantially but not completely protected the liver tissue, while the combined use of LC and GB may be more effective in treating liver damage caused by high cholesterol than either supplement alone by regulating hepatic oxidative stress and the protein expression of GLP-1 and β-Cat.

A high-dose of ursodeoxycholic acid treatment alleviates liver inflammation by remodeling gut microbiota and bile acid profile in a mouse model of non-alcoholic steatohepatitis

Ursodeoxycholic acid (UDCA) is a hydrophilic bile acid commonly used for treating cholestatic liver disease. However, its efficacy on non-alcoholic steatohepatitis (NASH) was controversial. This study aimed to investigate the impact of a high dosage of UDCA on a mouse model of NASH. Forty 6-week-old mice were fed a high-fat high-cholesterol (HFHC) diet for 12 weeks to establish a mouse model of NASH, and then divided into four groups: two groups transitioned to a normal diet, and the other two groups maintained the HFHC diet. Each group was administered a daily dosage of 300 mg/kg of UDCA or saline for a period of 8 weeks. The 16 s ribosomal RNA genes extracted from mice fecal pellets were sequenced using next-generation sequencing techniques. Serum bile acid profiles were quantified using liquid chromatography electrospray ionization tandem mass spectrometry method. The results showed that UDCA treatment ameliorated liver inflammation, without affecting liver fibrosis. UDCA treatment reduced the relative abundance of the genera Bacteroides, Parabacteroides, and Intestinimonas, whereas increased the relative abundance of the genera norank_f_Muribaculaceae and Parasutterella in the HFHC-maintaining groups. The serum levels of total bile acids and total primary bile acids increased, whereas those of endogenous primary bile acids decreased after UDCA treatment. Correlation analysis showed that primary bile acids were negatively correlated with the genera norank_f_Christensenellaceae and unclassified_f_Ruminococcaceae. In conclusion, a high dosage of UDCA can alleviate liver inflammation, probably by modifying the composition of gut microbiota and serum bile acid profiles in NASH mice.

Haplo-insufficiency of Profilin1 in vascular endothelial cells is beneficial but not sufficient to confer protection against experimentally induced atherosclerosis.

Actin cytoskeleton plays an important role in various aspects of atherosclerosis, a key driver of ischemic heart disease. Actin-binding protein Profilin1 (Pfn1) is overexpressed in atherosclerotic plaques in human disease, and Pfn1, when partially depleted globally in all cell types, confers atheroprotection in vivo. This study investigates the impact of endothelial cell (EC)-specific partial loss of Pfn1 expression in atherosclerosis development. We utilized mice engineered for conditional heterozygous knockout of the Pfn1 gene in ECs, with atherosclerosis induced by depletion of hepatic LDL receptor by gene delivery of PCSK9 combined with high-cholesterol diet. Our studies show that partial depletion of EC Pfn1 has certain beneficial effects marked by dampening of select pro-atherogenic cytokines (CXCL10 and IL7) with concomitant reduction in cytotoxic T cell abundance but is not sufficient to reduce hyperlipidemia and confer atheroprotection in vivo. In light of these findings, we conclude that atheroprotective phenotype conferred by global Pfn1 haplo-insufficiency requires contributions of additional cell types that are relevant for atherosclerosis progression.

Long non-coding RNA FGD5 antisense RNA 1 targets Baculovirus inhibitor 5 via microRNA-497-5p to alleviate calcific aortic valve disease.

Calcific aortic valve disease (CAVD) is featured by thickening and calcification of the aortic valve. Osteoblast differentiation is a crucial step in valve calcification. Long non-coding RNAs (LncRNAs) participate in the osteogenic differentiation of mesenchymal cells. However, the character of lncRNA FGD5 antisense RNA 1 (FGD5-AS1) in CAVD is uncertain. After collection of human aortic valve tissue samples, detection of FGD5-AS1, microRNA (miR)-497-5p and Baculovirus inhibitor 5 (BIRC5) was conducted. Valve mesenchymal cells were isolated from CAVD patients and induced to differentiate to osteoblasts, and transfected with FGD5-AS1, miR-497-5p and BIRC5 plasmids. Detection of the alkaline phosphatase activity was after osteogenic induction of human aortic valve interstitial cells (hAVICs); Detection of the degree of calcium nodules and osteoblast differentiation markers (RUNX2 and OPN) was conducted. After establishment of a mouse model of CAVD, detection of the thickness of aortic valve leaflets, and the degree of calcification of the valve leaflets, and evaluation of echocardiographic parameters were implemented. Experimental data manifested in CAVD patients, lncRNAFGD5-AS1 and BIRC5 were reduced, but miR-497-5p was elevated; Enhancing lncRNA FGD5-AS1 or repressing miR-497-5p mitigated CAVD by restraining osteogenic differentiation; LncRNA FGD5-AS1 sponged miR-497-5p to target BIRC5; Repressive BIRC5 turned around the therapeutic action of elevated FGD5-AS1 or depressed miR-497-5p on hAVICs; Enhancive FGD5-AS1 in vivo was available to reduce ApoE-/- mouse CAVD induced via high cholesterol diet. All in all, lncRNAFGD5-AS1 targets BIRC5 via miR-497-5p to alleviate CAVD.

Impaired astrocytic synaptic function by peripheral cholesterol metabolite 27-hydroxycholesterol.

Astrocytes represent the most abundant cell type in the brain, where they play critical roles in synaptic transmission, cognition, and behavior. Recent discoveries show astrocytes are involved in synaptic dysfunction during Alzheimer's disease (AD). AD patients have imbalanced cholesterol metabolism, demonstrated by high levels of side-chain oxidized cholesterol known as 27-hydroxycholesterol (27-OH). Evidence from our laboratory has shown that elevated 27-OH can abolish synaptic connectivity during neuromaturation, but its effect on astrocyte function is currently unclear. Our results suggest that elevated 27-OH decreases the astrocyte function in vivo in Cyp27Tg, a mouse model of brain oxysterol imbalance. Here, we report a downregulation of glutamate transporters in the hippocampus of CYP27Tg mice together with increased GFAP. GLT-1 downregulation was also observed when WT mice were fed with high-cholesterol diets. To study the relationship between astrocytes and neurons, we have developed a 3D co-culture system that allows all the cell types from mice embryos to differentiate in vitro. We report that our 3D co-cultures reproduce the effects of 27-OH observed in 2D neurons and in vivo. Moreover, we found novel degenerative effects in astrocytes that do not appear in 2D cultures, together with the downregulation of glutamate transporters GLT-1 and GLAST. We propose that this transporter dysregulation leads to neuronal hyperexcitability and synaptic dysfunction based on the effects of 27-OH on astrocytes. Taken together, these results report a new mechanism linking oxysterol imbalance in the brain and synaptic dysfunction through effects on astrocyte function.

Remodeling Intestinal Microbiota Alleviates Severe Combined Hyperlipidemia-Induced Nonalcoholic Steatohepatitis and Atherosclerosis in LDLR-/- Hamsters.

Combined hyperlipidemia (CHL) manifests as elevated cholesterol and triglycerides, associated with fatty liver and cardiovascular diseases. Emerging evidence underscores the crucial role of the intestinal microbiota in metabolic disorders. However, the potential therapeutic viability of remodeling the intestinal microbiota in CHL remains uncertain. In this study, CHL was induced in low-density lipoprotein receptor-deficient (LDLR-/-) hamsters through an 8-week high-fat and high-cholesterol (HFHC) diet or a 4-month high-cholesterol (HC) diet. Placebo or antibiotics were administered through separate or cohousing approaches. Analysis through 16S rDNA sequencing revealed that intermittent antibiotic treatment and the cohousing approach effectively modulated the gut microbiota community without impacting its overall abundance in LDLR-/- hamsters exhibiting severe CHL. Antibiotic treatment mitigated HFHC diet-induced obesity, hyperglycemia, and hyperlipidemia, enhancing thermogenesis and alleviating nonalcoholic steatohepatitis (NASH), concurrently reducing atherosclerotic lesions in LDLR-/- hamsters. Metabolomic analysis revealed a favorable liver lipid metabolism profile. Increased levels of microbiota-derived metabolites, notably butyrate and glycylglycine, also ameliorated NASH and atherosclerosis in HFHC diet-fed LDLR-/- hamsters. Notably, antibiotics, butyrate, and glycylglycine treatment exhibited protective effects in LDLR-/- hamsters on an HC diet, aligning with outcomes observed in the HFHC diet scenario. Our findings highlight the efficacy of remodeling gut microbiota through antibiotic treatment and cohousing in improving obesity, NASH, and atherosclerosis associated with refractory CHL. Increased levels of beneficial microbiota-derived metabolites suggest a potential avenue for microbiome-mediated therapies in addressing CHL-associated diseases.

Oncolytic adenovirus encoding apolipoprotein A1 suppresses metastasis of triple-negative breast cancer in mice

BackgroundDysregulation of cholesterol metabolism is associated with the metastasis of triple-negative breast cancer (TNBC). Apolipoprotein A1 (ApoA1) is widely recognized for its pivotal role in regulating cholesterol efflux and maintaining cellular cholesterol homeostasis. However, further exploration is needed to determine whether it inhibits TNBC metastasis by affecting cholesterol metabolism. Additionally, it is necessary to investigate whether ApoA1-based oncolytic virus therapy can be used to treat TNBC.MethodsIn vitro experiments and mouse breast cancer models were utilized to evaluate the molecular mechanism of ApoA1 in regulating cholesterol efflux and inhibiting breast cancer progression and metastasis. The gene encoding ApoA1 was inserted into the adenovirus genome to construct a recombinant adenovirus (ADV-ApoA1). Subsequently, the efficacy of ADV-ApoA1 in inhibiting the growth and metastasis of TNBC was evaluated in several mouse models, including orthotopic breast cancer, spontaneous breast cancer, and human xenografts. In addition, a comprehensive safety assessment of Syrian hamsters and rhesus monkeys injected with oncolytic adenovirus was conducted.ResultsThis study found that dysregulation of cholesterol homeostasis is critical for the progression and metastasis of TNBC. In a mouse orthotopic model of TNBC, a high-cholesterol diet promoted lung and liver metastasis, which was associated with keratin 14 (KRT14), a protein responsible for TNBC metastasis. Furthermore, studies have shown that ApoA1, a cholesterol reverse transporter, inhibits TNBC metastasis by regulating the cholesterol/IKBKB/FOXO3a/KRT14 axis. Moreover, ADV-ApoA1 was found to promote cholesterol efflux, inhibit tumor growth, reduce lung metastasis, and prolonged the survival of mice with TNBC. Importantly, high doses of ADV-ApoA1 administered intravenously and subcutaneously were well tolerated in rhesus monkeys and Syrian hamsters.ConclusionsThis study provides a promising oncolytic virus treatment strategy for TNBC based on targeting dysregulated cholesterol metabolism. It also establishes a basis for subsequent clinical trials of ADV-ApoA1 in the treatment of TNBC.