Potential role of proteasome on c-jun related signaling in hypercholesterolemia induced atherosclerosis

Two sides of the same coin: Non-alcoholic fatty liver disease and atherosclerosis

The prevalence of non-alcoholic fatty liver disease (NAFLD) and atherosclerosis remain high, which is primarily due to widespread adoption of a western diet and sedentary lifestyle. NAFLD, together with advanced forms of this disease such as non-alcoholic steatohepatitis (NASH) and cirrhosis, are closely associated with atherosclerotic-cardiovascular disease (ASCVD). In this review, we discussed the association between NAFLD and atherosclerosis and expounded on the common molecular biomarkers underpinning the pathogenesis of both NAFLD and atherosclerosis. Furthermore, we have summarized the mode of function and potential clinical utility of existing drugs in the context of these diseases.

MiR-130a-3p inhibits endothelial inflammation by regulating the expression of MAPK8 in endothelial cells

MicroRNA-130a-3p (miR-130a-3p) has been reported as closely related to atherosclerosis (AS). This study is to survey the effects of miR-130a-3p in endothelial cells (ECs) treated with oxidized low-density lipoprotein (ox-LDL) and explore underlying mechanisms. The proliferation and apoptosis of ox-LDL-treated HUVEC cells were determined by CCK-8, EdU, and flow cytometry assays. ELISA and Western blot analysis measured the expressions of cytokines and protein levels. Bioinformatics and dual-luciferase reporter assay were performed to predict and confirm that Mitogen-activated protein kinase 8 (MAPK8) was a direct target of miR-130a-3p, and MAPK8 was negatively associated with miR-130a-3p. As expected, miR-130a-3p was down-regulated in ox-LDL-treated HUVEC cells, and up-regulation of miR-130a-3p promoted proliferation and inhibited apoptosis of ox-LDL-treated HUVEC cells. Furthermore, miR-130a-3p mimics suppressed the expressions of TNF-α and IL-6 and decreased the protein levels of VCAM-1, ICAM-1 and E-selectin. MAPK8 was highly expressed in ox-LDL-treated HUVEC cells, and silence of MAPK8 promoted proliferation inhibited apoptosis, suppressed inflammatory responses, and decreased the levels of VCAM-1, ICAM-1, and E-selectin, over-expression of MAPK8 partially restored the functional effects of miR-130a-3p on proliferation, inflammatory responses, and the expressions of VCAM-1, ICAM-1 and E-selectin. This study indicates that miR-130a-3p may emerge as an effective target for treating AS.

BATMAN-TCM 2.0: an enhanced integrative database for known and predicted interactions between traditional Chinese medicine ingredients and target proteins

Traditional Chinese medicine (TCM) is increasingly recognized and utilized worldwide. However, the complex ingredients of TCM and their interactions with the human body make elucidating molecular mechanisms challenging, which greatly hinders the modernization of TCM. In 2016, we developed BATMAN-TCM 1.0, which is an integrated database of TCM ingredient-target protein interaction (TTI) for pharmacology research. Here, to address the growing need for a higher coverage TTI dataset, and using omics data to screen active TCM ingredients or herbs for complex disease treatment, we updated BATMAN-TCM to version 2.0 (http://bionet.ncpsb.org.cn/batman-tcm/). Using the same protocol as version 1.0, we collected 17 068 known TTIs by manual curation (with a 62.3-fold increase), and predicted ∼2.3 million high-confidence TTIs. In addition, we incorporated three new features into the updated version: (i) it enables simultaneous exploration of the target of TCM ingredient for pharmacology research and TCM ingredients binding to target proteins for drug discovery; (ii) it has significantly expanded TTI coverage; and (iii) the website was redesigned for better user experience and higher speed. We believe that BATMAN-TCM 2.0, as a discovery repository, will contribute to the study of TCM molecular mechanisms and the development of new drugs for complex diseases.

Vitamin E Supplementation and Cardiovascular Health: A Comprehensive Review

This article conducts a thorough investigation into the potential role of vitamin E in preventing cardiovascular diseases (CVDs) in the context of shifting mortality patterns from infectious diseases to the continued prominence of CVDs in modern medicine. The primary focus is on vitamin E's antioxidant properties and its specific ability to counter lipid peroxidation, a pivotal process in the early stages of atherosclerosis, a precursor to CVDs. The research spans a wide range of methodologies, including in vitro, in vivo, clinical, and experimental studies, examining how vitamin E affects critical aspects of cardiovascular health, such as signaling pathways, gene expression, inflammation, and cholesterol metabolism. It also explores vitamin E's influence on complex processes like smooth muscle cell development, oxidative stress reduction, foam cell formation, and the stability of atherosclerotic plaques. In the context of clinical studies, the article presents findings that both support and yield inconclusive results regarding the impact of vitamin E supplementation on CVDs. It acknowledges the intricate interplay of factors such as patient selection, pathophysiological conditions, and genetic variations, all of which can significantly influence the efficacy of vitamin E. The article underscores the need for ongoing research, with a specific focus on understanding the regulatory metabolites of vitamin E and their roles in modulating cellular processes relevant to CVDs. It highlights the potential for innovative therapeutic approaches based on a deeper comprehension of vitamin E's multifaceted effects. However, it also candidly addresses the challenges of translating clinical trial findings into practical applications and emphasizes the importance of considering diverse variables to optimize therapeutic outcomes. In summary, this meticulously conducted study provides a comprehensive examination of vitamin E's potential as a preventive agent against CVDs, recognizing the complexity of the subject and the need for continued research to unlock its full potential in cardiovascular health.

Integrative analysis reveals early epigenetic alterations in high-grade serous ovarian carcinomas

High-grade serous ovarian carcinoma (HGSOC) is the most lethal gynecological malignancy. To date, the profiles of gene mutations and copy number alterations in HGSOC have been well characterized. However, the patterns of epigenetic alterations and transcription factor dysregulation in HGSOC have not yet been fully elucidated. In this study, we performed integrative omics analyses of a series of stepwise HGSOC model cells originating from human fallopian tube secretory epithelial cells (HFTSECs) to investigate early epigenetic alterations in HGSOC tumorigenesis. Assay for transposase-accessible chromatin using sequencing (ATAC-seq), chromatin immunoprecipitation sequencing (ChIP-seq), and RNA sequencing (RNA-seq) methods were used to analyze HGSOC samples. Additionally, protein expression changes in target genes were confirmed using normal HFTSECs, serous tubal intraepithelial carcinomas (STICs), and HGSOC tissues. Transcription factor motif analysis revealed that the DNA-binding activity of the AP-1 complex and GATA family proteins was dysregulated during early tumorigenesis. The protein expression levels of JUN and FOSL2 were increased, and those of GATA6 and DAB2 were decreased in STIC lesions, which were associated with epithelial-mesenchymal transition (EMT) and proteasome downregulation. The genomic region around the FRA16D site, containing a cadherin cluster region, was epigenetically suppressed by oncogenic signaling. Proteasome inhibition caused the upregulation of chemokine genes, which may facilitate immune evasion during HGSOC tumorigenesis. Importantly, MEK inhibitor treatment reversed these oncogenic alterations, indicating its clinical effectiveness in a subgroup of patients with HGSOC. This result suggests that MEK inhibitor therapy may be an effective treatment option for chemotherapy-resistant HGSOC.

Cholesterol accumulation in hepatocytes mediates IRE1/p38 branch of endoplasmic reticulum stress to promote nonalcoholic steatohepatitis

Non-alcoholic fatty liver disease (NAFLD), based on the elevating obesity incidence, is one of the major health issue worldwide. Transition from NAFLD to non-alcoholic steatohepatitis (NASH) is driven by increased apoptosis and is relevant to higher morbidity rates. In regard to limited understanding on cholesterol mediated hepatocyte alterations in NALFD/NASH transition, we investigated endoplasmic reticulum (ER) stress and related apoptosis. Our findings suggest that cholesterol upregulates ER stress and enhances C/EBP homologous protein (CHOP) either in hypercholesterolemic rabbits or in hepatocytes treated with liposome-cholesterol complex. Mechanistically, cholesterol accumulation in hepatocytes activates IRE1/p38 branch of ER stress, stimulating CHOP levels. In liver tissues of cholesterol fed rabbits, α-tocopherol supplementation decreased IRE1/p38/CHOP activation and prevented NASH development. Thus, our study provides a critical role of hepatocyte cholesterol in inducing IRE1/p38/CHOP pathway and suggests novel candidates for therapeutic targets against NASH.

Identifying potential signatures for atherosclerosis in the context of predictive, preventive, and personalized medicine using integrative bioinformatics approaches and machine-learning strategies

Background

Atherosclerosis is a major contributor to morbidity and mortality worldwide. Although several molecular markers associated with atherosclerosis have been developed in recent years, the lack of robust evidence hinders their clinical applications. For these reasons, identification of novel and robust biomarkers will directly contribute to atherosclerosis management in the context of predictive, preventive, and personalized medicine (PPPM). This integrative analysis aimed to identify critical genetic markers of atherosclerosis and further explore the underlying molecular immune mechanism attributing to the altered biomarkers.

Methods

Gene Expression Omnibus (GEO) series datasets were downloaded from GEO. Firstly, differential expression analysis and functional analysis were conducted. Multiple machine-learning strategies were then employed to screen and determine key genetic markers, and receiver operating characteristic (ROC) analysis was used to assess diagnostic value. Subsequently, cell-type identification by estimating relative subsets of RNA transcript (CIBERSORT) and a single-cell RNA sequencing (scRNA-seq) data were performed to explore relationships between signatures and immune cells. Lastly, we validated the biomarkers' expression in human and mice experiments.

Results

A total of 611 overlapping differentially expressed genes (DEGs) included 361 upregulated and 250 downregulated genes. Based on the enrichment analysis, DEGs were mapped in terms related to immune cell involvements, immune activating process, and inflaming signals. After using multiple machine-learning strategies, dehydrogenase/reductase 9 (DHRS9) and protein tyrosine phosphatase receptor type J (PTPRJ) were identified as critical biomarkers and presented their high diagnostic accuracy for atherosclerosis. From CIBERSORT analysis, both DHRS9 and PTPRJ were significantly related to diverse immune cells, such as macrophages and mast cells. Further scRNA-seq analysis indicated DHRS9 was specifically upregulated in macrophages of atherosclerotic lesions, which was confirmed in atherosclerotic patients and mice.

Conclusions

Our findings are the first to report the involvement of DHRS9 in the atherogenesis, and the proatherogenic effect of DHRS9 is mediated by immune mechanism. In addition, we confirm that DHRS9 is localized in macrophages within atherosclerotic plaques. Therefore, upregulated DHRS9 could be a novel potential target for the future predictive diagnostics, targeted prevention, patient stratification, and personalization of medical services in atherosclerosis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13167-022-00289-y.

Vitamin E Supplementation Enhances Lipid Oxidative Stability via Increasing Vitamin E Retention, Rather Than Gene Expression of MAPK-Nrf2 Signaling Pathway in Muscles of Broilers

Dietary vitamin E (VE) supplementation is a method to produce VE-enriched meat and improve meat lipid oxidative stability. We aimed to study the effect of the VE supplementation duration on meat lipid oxidative stability, VE retention, and antioxidant enzymes’ activity, and explore its relationship with the mitogen-activated protein kinases (MAPK)-nuclear factor-erythroid 2-related factor 2 (Nrf2) signaling pathway in broilers slaughtered after electrical stunning. A total of 240 male 18-day-old Arbor Acres Plus broilers were distributed to four treatments, with six replicates in each treatment, and ten broilers per replicate. Broilers were fed with a basal diet (no supplementation of VE) or VE diet (200 IU/kg VE, DL-α- tocopherol) for one (W1), two (W2), or three (W3) weeks before electrical stunning (130 mA, 60 Hz, for 1s) and slaughter. The VE retention was positively and linearly affected (p < 0.01) by the VE feeding duration at one to three weeks before slaughter, and negatively (all p < 0.01) related to the thiobarbituric acid reactive substance (TBARS) content in both breast and thigh muscles at d 0, d 2, and d 6 postmortem. The VE retention was negatively (p < 0.05) related to the gene expression of c-Jun N-terminal kinases 1 (JNK1) and 2 (JNK2), Nrf2 in breast muscles, and JNK1 and p38 MAPK in thigh muscles. In conclusion, dietary vitamin E supplementation at 200 IU/kg for three weeks before electrical stunning and slaughter improved lipid oxidative stability via increasing VE retention, rather than the regulation by gene expression of the MAPK-Nrf2 signaling pathway in skeletal muscles of broilers.

High cholesterol diet activates ER stress mediated apoptosis in testes tissue: Role of α-tocopherol

The seminiferous tubules where spermatogenesis occurs are enveloped and protected by the Sertoli cells to support germ cells undergoing meiosis to produce haploid gametes. Clearly, induction of apoptosis in seminiferous tubules leads to abnormalities in spermatogenesis and male infertility. Studies demonstrated that increased hyperlipidemia impairs male infertility and spermatogenesis by enhancing seminiferous tubules apoptosis. However, molecular mechanisms underlying high-cholesterol-mediated testicular damage remain poorly elucidated. In this scope, we established a rabbit model and investigated the role of endoplasmic reticulum (ER) stress on high cholesterol diet induced seminiferous tubule apoptosis. Histopatological examinations revealed increased seminifer tubule apoptosis in testes of rabbits fed high cholesterol diet. In addition, phosphorylated forms of IRE1 and PERK, two well-identified markers of ER stress, were significantly induced in accordance with high cholesterol diet. High cholesterol diet also exhibited CHOP induction in testes, indicating increased ER stress related apoptosis. Supplementation of α-tocopherol significantly attenuated cholesterol mediated ER stress, and restored seminiferous tubules apoptosis. Taken together, our findings suggest that α-tocopherol might be capable to reduce testicular damage via ameliorating histopatological features and inhibiting seminiferous tubules apoptosis in hypercholesterolemic rabbits.

alpha-Tocopherol supplementation reduces inflammation and apoptosis in high cholesterol mediated nonalcoholic steatohepatitis

Inflammation and apoptosis signaling are crucial steps in the progression from nonalcoholic fatty liver disease (NAFLD) to nonalcoholic steatohepatitis (NASH). Alpha-tocopherol, the most active form of vitamin E, is an important modulator of signaling mechanisms, but its involvement to cholesterol-induced NASH pathogenesis remains poorly defined. Herein we have reported a novel effect of α-tocopherol in the transition from hepatic steatosis to NASH. High cholesterol diet alone (without α-tocopherol) in rabbits elevated NASH development as indicated by increased inflammatory response, apoptotic activity and liver fibrosis. Such elevation results from induction of signaling mechanisms since the expressions of IL1β, phospho c-Jun/c-Jun ratio, JNK, caspase 9, CHOP and Bax were increased, and recruitment of macrophage, α-smooth muscle actin (α-SMA) and COL1A1 into the liver tissue were induced. Alpha-tocopherol supplementation inhibited inflammatory response, apoptosis and fibrosis development without affecting lipid accumulation in high cholesterol-induced NASH. Specifically, α-tocopherol lowered the inflammatory level as observed by reduced macrophage infiltration and JNK/c-Jun signaling. Lower inflammatory status co-occurred with the reduction of CHOP and Bax expressions as well as fibrosis-related COL1A1 and α-SMA levels. Taken together, α-tocopherol supplementation inhibits cholesterol-induced NASH development by lowering JNK/c-Jun/inflammation axis in addition to JNK/CHOP/apoptosis signaling, which might contribute to resistance against NAFLD/NASH transition.

The Role of Ubiquitin E3 Ligase in Atherosclerosis

Atherosclerosis is a chronic inflammatory vascular disease. Atherosclerotic cardiovascular disease is the main cause of death in both developed and developing countries. Many pathophysiological factors, including abnormal cholesterol metabolism, vascular inflammatory response, endothelial dysfunction and vascular smooth muscle cell proliferation and apoptosis, contribute to the development of atherosclerosis and the molecular mechanisms underlying the development of atherosclerosis are not fully understood. Ubiquitination is a multistep post-translational protein modification that participates in many important cellular processes. Emerging evidence suggests that ubiquitination plays important roles in the pathogenesis of atherosclerosis in many ways, including regulation of vascular inflammation, endothelial cell and vascular smooth muscle cell function, lipid metabolism and atherosclerotic plaque stability. This review summarizes important contributions of various E3 ligases to the development of atherosclerosis. Targeting ubiquitin E3 ligases may provide a novel strategy for the prevention of the progression of atherosclerosis.

High-throughput profiling reveals perturbation of endoplasmic reticulum stress-related genes in atherosclerosis induced by high-cholesterol diet and the protective role of vitamin E

Formation of atherosclerotic plaques, called atherogenesis, is a complex process affected by genetic and environmental factors. It was proposed that endoplasmic reticulum (ER) stress is an important factor in the pathogenesis of atherosclerosis and that vitamin E affects atherosclerotic plaque formation via its antioxidant properties. Here, we investigated ER stress-related molecular mechanisms in high-cholesterol diet (HCD, 2%)-induced atherosclerosis model and the role of vitamin E supplementation in it, beyond its antioxidant properties. The consequences of HCD and vitamin E supplementation were examined by determining protein levels of ER stress markers in aortic tissues. As vitamin E supplementation acts on several unfolded protein response (UPR) factors, it decreased ER stress induced by HCD. To elucidate the associated pathways, gene expression profiling was performed, revealing differentially expressed genes enriched in ER stress-related pathways such as the proteasome and the apoptosis pathways. We further assessed the proteasomal activity impaired by HCD in the aorta and showed that vitamin E reversed it to that of control animals. Overall, the study characterized the effects of HCD and vitamin E on ER stress-related gene expression, revealing the role of proteolytic systems during atherogenesis.

Cholesterol induced autophagy via IRE1/JNK pathway promotes autophagic cell death in heart tissue

BACKGROUND

Cardiovascular diseases (CVDs), with highest mortality and morbidity rates, are the major cause of death in the world. Due to the limited information on heart tissue changes, mediated by hypercholesterolemia, we planned to investigate molecular mechanisms of endoplasmic reticulum (ER) stress and related cell death in high cholesterol fed rabbit model and possible beneficial effects of α-tocopherol.

METHODS

Molecular changes in rabbit heart tissue and cultured cardiomyocytes (H9c2 cells) were measured by western blotting, qRT-PCR, immunflouresence and flow cytometry experiments. Histological modifications were assessed by light and electron microscopes, while degradation of mitochondria was quantified through confocal microscope.

RESULTS

Feeding rabbits 2% cholesterol diet for 8 weeks and treatment of cultured cardiomyocytes with 10 μg/mL cholesterol for 3 h induced excessive autophagic activity via IRE1/JNK pathway. While no change in ER-associated degradation (ERAD) and apoptotic cell death were determined, electron and confocal microscopy analyses in cholesterol supplemented rabbits revealed significant parameters of autophagic cell death, including cytoplasmic autophagosomes, autolysosomes and organelle loss in juxtanuclear area as well as mitochondria engulfment by autophagosome. Either inhibition of ER stress or JNK in cultured cardiomyocytes or α-tocopherol supplementation in rabbits could counteract the effects of cholesterol.

CONCLUSION

Our findings underline the essential role of hypercholesterolemia in stimulating IRE1/JNK branch of ER stress response which then leads to autophagic cell death in heart tissue. Results also showed α-tocopherol as a promising regulator of autophagic cell death in cardiomyocytes.

TRIM7 promotes proliferation and migration of vascular smooth muscle cells in atherosclerosis through activating c-Jun/AP-1

Atherosclerosis (AS), with associated risk of stroke or cerebrovascular disease, is one of the most common causes of death globally. It has been well established that tripartite motif-containing protein 7 Tripartite Motif-containing 7 (Trim7), as an E3 ubiquitin protein ligase, is involved in protein ubiquitination and thus regulating cellular proliferation. Moreover, TRIM7 is upregulated in advanced carotid AS. However, the detailed mechanism of TRIM7 on regulation of AS remains unclear. In the present study, we firstly discovered that TRIM7 expression was robustly induced in platelet-derived growth factor type BB-treated vascular smooth muscle cells (VSMCs) and human atherosclerotic plaques. Functional approaches established that knockdown of TRIM7 inhibited proliferation and migration of VSMCs, as well as arrested the cell cycle at G1-S, thus suppressing AS progression. Our results also identified that c-Jun/activator protein 1 (AP-1) signaling pathway was activated by TRIM7. Moreover, gain- and loss-of-function studies revealed that TRIM7 could promote proliferation and migration of VSMCs via activation of c-Jun/AP-1 signaling pathway. Finally, by using atherogenic apolipoprotein E-deficient (apoE-/-) C57BL/6 mice with high-fat diet AS model, we demonstrated that interference of TRIM7 could effectively mitigate in vivo AS via inactivation of c-Jun/AP-1 signaling pathway. In general, activation of c-Jun/AP-1 signaling pathway via TRIM7 could be an important mechanism in AS progression, thus shedding light on the development of novel therapeutics to the treatment of the disease.

Fasting is not required for measuring plasma lipid levels in rabbits

Plasma lipid and glucose levels are important parameters for evaluating the onset and development of metabolic and cardiovascular diseases. In clinical and experimental studies of humans or mice, fasting is often required before testing plasma lipid and glucose levels. The rabbit is a valuable animal model for cardiovascular disease research. However, whether fasting is necessary for measuring plasma lipid and glucose levels in rabbits remains unclear. In the current study, 12 healthy Japanese white rabbits (males weighing 2.5-3.0 kg) were randomly divided into a chow diet group (n = 6) and a high cholesterol diet group (n = 6). They were fed either a standard chow diet or a chow diet supplemented with 0.5% cholesterol and 3% corn oil for 12 weeks. After 12 weeks, the plasma levels of total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and glucose were measured before and after various fasting durations (8, 12, 16, 20 and 24 h). The results showed that there were no significant differences in lipid levels between the fasting and non-fasting samples, whereas glucose levels were lower after 8 h of fasting than in the absence of fasting. Moreover, the glucose levels were restored to normal after 8 h of refeeding. These results indicate that fasting does not affect plasma lipid values in rabbits but that fasting is important for determining the glucose level in rabbits. These findings may be helpful for future rabbit experiments and beneficial for animal welfare.

Gene expression analysis of vascular pathophysiology related to anti-TNF treatment in rheumatoid arthritis

OBJECTIVES

Impaired vascular pathophysiology and increased cardiovascular (CV) mortality are associated with rheumatoid arthritis (RA). To date, no genomic analysis of RA- and RA treatment-related vascular pathophysiology has been published. In this pilot study, we performed gene expression profiling in association with vascular pathophysiology in RA patients.

METHODS

Sixteen and 19 biologic-naïve RA patients were included in study 1 and study 2, respectively. In study 1, genetic signatures determined by microarray were related to flow-mediated vasodilation (FMD), pulse-wave velocity (PWV), and common carotid intima-media thickness (IMT) of patients. In study 2, clinical response (cR) vs non-response (cNR) to 1-year etanercept (ETN) or certolizumab pegol (CZP) treatment, as well as "vascular" response (vR) vs non-response (vNR) to biologics, were also associated with genomic profiles. Multiple testing could not be performed due to the relatively small number of patients; therefore, our pilot study may lack power.

RESULTS

In study 1, multiple genes were up- or downregulated in patients with abnormal vs normal FMD, IMT, and PWV. In study 2, there were 13 cR and 6 cNR anti-tumor necrosis factor (TNF)-treated patients. In addition, 10, 9, and 8 patients were FMD-20%, IMT-20%, and PWV-20% responders. Again, vascular responder status was associated with changes of the expression of various genes. The highest number of genes showing significant enrichment were involved in positive regulation of immune effector process, regulation of glucose transport, and Golgi vesicle budding.

CONCLUSION

Differential expression of multiple genetic profiles may be associated with vascular pathophysiology associated with RA. Moreover, distinct genetic signatures may also be associated with clinical and vascular responses to 1-year anti-TNF treatment.

Vitamin E: Regulatory role in the cardiovascular system

Cardiovascular disease (CVD) is one of the major causes of morbidity and mortality, all around the world. Vitamin E is an important nutrient influencing key cellular and molecular mechanisms as well as gene expression regulation centrally involved in the prevention of CVD. Cell culture and animal studies have focused on the identification of vitamin E regulated signaling pathways and involvement on inflammation, lipid homeostasis, and atherosclerotic plaque stability. While some of these vitamin E functions were verified in clinical trials, some of the positive effects were not translated into beneficial outcomes in epidemiological studies. In recent years, the physiological metabolites of vitamin E, including the liver derived (long- and short-chain) metabolites and phosphorylated (α-, γ-tocopheryl phosphate) forms, have also provided novel mechanistic insight into CVD regulation that expands beyond the vitamin E precursor. It is certain that this emerging insight into the molecular and cellular action of vitamin E will help to design further studies, either in animal models or clinical trials, on the reduction of risk for CVDs. This review focuses on vitamin E-mediated preventive cardiovascular effects and discusses novel insights into the biology and mechanism of action of vitamin E metabolites in CVD. © 2019 IUBMB Life, 71(4):507-515, 2019.

High Cholesterol Diet-Induced Changes in Oxysterol and Scavenger Receptor Levels in Heart Tissue

Involvement of high cholesterol and oxidative stress in cardiovascular diseases is well studied, as it can be hypothesized that various products originated from lipid peroxidation, such as oxysterols, or affected protein expression might lead to cardiomyocyte damage followed by the pathological modifications. Although oxidation of excessive cholesterol to oxysterols in elevated stress conditions is identified by a number of studies, the role of a high cholesterol diet in regulating fatty acid and oxysterol accumulation, together with scavenger receptor mRNA levels, in the heart remains little investigated. Our study provides a detailed analysis of the changes in fatty acid, oxysterol, and scavenger receptor profiles and its relation with histological alterations in the heart tissue. We evaluated alterations of fatty acid composition, by the GC-MS method, while 4β-, 25-, and 27-hydroxycholesterol and 7-ketocholesterol levels by means of LC-MS/MS in high cholesterol diet-fed rabbits. Additionally, a number of proteins related to lipid metabolism and scavenger receptor mRNA expressions were evaluated by Western blotting and RT-PCR. According to our in vivo results, a high cholesterol diet enhances a number of unsaturated fatty acids, oxysterols, and LXRα, in addition to CD36, CD68, CD204, and SR-F1 expressions while α-tocopherol supplementation decreases LXRα and SR expressions together with an increase in 27-hydroxycholesterol and ABCA1 levels. Our results indicated that the high cholesterol diet modulates proteins related to lipid metabolism, which might result in the malfunction of the heart and α-tocopherol shows its beneficial effects. We believe that this work will lead the generation of different theories in the development of heart diseases.

Anti-oxidative and anti-inflammatory effects of Rosa Mosqueta oil supplementation in rat liver ischemia-reperfusion

Ischemia-reperfusion (IR) is a deleterious condition associated with liver transplantation or resection that involves pro-oxidant and pro-inflammatory mechanisms.

Oxidative Stress: Harms and Benefits for Human Health

Oxidative stress is a phenomenon caused by an imbalance between production and accumulation of oxygen reactive species (ROS) in cells and tissues and the ability of a biological system to detoxify these reactive products. ROS can play, and in fact they do it, several physiological roles (i.e., cell signaling), and they are normally generated as by-products of oxygen metabolism; despite this, environmental stressors (i.e., UV, ionizing radiations, pollutants, and heavy metals) and xenobiotics (i.e., antiblastic drugs) contribute to greatly increase ROS production, therefore causing the imbalance that leads to cell and tissue damage (oxidative stress). Several antioxidants have been exploited in recent years for their actual or supposed beneficial effect against oxidative stress, such as vitamin E, flavonoids, and polyphenols. While we tend to describe oxidative stress just as harmful for human body, it is true as well that it is exploited as a therapeutic approach to treat clinical conditions such as cancer, with a certain degree of clinical success. In this review, we will describe the most recent findings in the oxidative stress field, highlighting both its bad and good sides for human health.

Vitamin E: Emerging aspects and new directions

The discovery of vitamin E will have its 100th anniversary in 2022, but we still have more questions than answers regarding the biological functions and the essentiality of vitamin E for human health. Discovered as a factor essential for rat fertility and soon after characterized for its properties of fat-soluble antioxidant, vitamin E was identified to have signaling and gene regulation effects in the 1980s. In the same years the cytochrome P-450 dependent metabolism of vitamin E was characterized and a first series of studies on short-chain carboxyethyl metabolites in the 1990s paved the way to the hypothesis of a biological role for this metabolism alternative to vitamin E catabolism. In the last decade other physiological metabolites of vitamin E have been identified, such as α-tocopheryl phosphate and the long-chain metabolites formed by the ω-hydroxylase activity of cytochrome P-450. Recent findings are consistent with gene regulation and homeostatic roles of these metabolites in different experimental models, such as inflammatory, neuronal and hepatic cells, and in vivo in animal models of acute inflammation. Molecular mechanisms underlying these responses are under investigation in several laboratories and side-glances to research on other fat soluble vitamins may help to move faster in this direction. Other emerging aspects presented in this review paper include novel insights on the mechanisms of reduction of the cardiovascular risk, immunomodulation and antiallergic effects, neuroprotection properties in models of glutamate excitotoxicity and spino-cerebellar damage, hepatoprotection and prevention of liver toxicity by different causes and even therapeutic applications in non-alcoholic steatohepatitis. We here discuss these topics with the aim of stimulating the interest of the scientific community and further research activities that may help to celebrate this anniversary of vitamin E with an in-depth knowledge of its action as vitamin.

Regulation of Nox enzymes expression in vascular pathophysiology: Focusing on transcription factors and epigenetic mechanisms

NADPH oxidases (Nox) represent a family of hetero-oligomeric enzymes whose exclusive biological function is the generation of reactive oxygen species (ROS). Nox-derived ROS are essential modulators of signal transduction pathways that control key physiological activities such as cell growth, proliferation, migration, differentiation, and apoptosis, immune responses, and biochemical pathways. Enhanced formation of Nox-derived ROS, which is generally associated with the up-regulation of different Nox subtypes, has been established in various pathologies, namely cardiovascular diseases, diabetes, obesity, cancer, and neurodegeneration. The detrimental effects of Nox-derived ROS are related to alterations in cell signalling and/or direct irreversible oxidative damage of nucleic acids, proteins, carbohydrates, and lipids. Thus, understanding of transcriptional regulation mechanisms of Nox enzymes have been extensively investigated in an attempt to find ways to counteract the excessive formation of Nox-derived ROS in various pathological states. Despite the numerous existing data, the molecular pathways responsible for Nox up-regulation are not completely understood. This review article summarizes some of the recent advances and concepts related to the regulation of Nox expression in the vascular pathophysiology. It highlights the role of transcription factors and epigenetic mechanisms in this process. Identification of the signalling molecules involved in Nox up-regulation, which is associated with the onset and development of cardiovascular dysfunction may contribute to the development of novel strategies for the treatment of cardiovascular diseases.

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Nox is a unique class of enzymes whose sole function is the generation of ROS.

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Nox-derived ROS play a major role in cell physiology.

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Enhanced expression and activation of Nox has been reported in numerous pathologies.

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Nox expression is regulated via complex transcription factor-epigenetic mechanisms.

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Understanding of Nox regulation is essential to counteract ROS-induced cell damage.

Whole-body imaging of a hypercholesterolemic female zebrafish by using synchrotron X-ray micro-CT

Zebrafish has been used as a powerful model system in biological and biomedical studies studying development and diseases. Comparative, functional, and developmental studies on zebrafish morphology require precise visualization of 3D morphological structures. Few methods that can visualize whole-volume of zebrafish tissues are available because optical bio-imaging methods are limited by pigmentation and hard tissues. To overcome these limitations, the 3D microstructures of a hypercholesterolemic zebrafish model are visualized using synchrotron X-ray micro-computed tomography (SR-μCT). The model spatial resolution ranged from sub- to several microns. The microstructures of various zebrafish organs are observed by combining high-contrast staining (osmium tetroxide and uranyl acetate) and embedding a protocol to enhance the image contrast of soft tissues. Furthermore, blood vessels are identified using a barium sulfate injection technique. The internal organs and cells, such as liver, intestine, oocytes, and adipocytes, of a hypercholesterolemic zebrafish are compared with those of normal organs and cells. The SR-μCT is useful for understanding the pathogenesis of circulatory vascular diseases by detecting the modifications in the 3D morphological structures of the whole body of the zebrafish. This bio-imaging technique can be readily used to study other disease models.