Cholesterol metabolism: A review of how ageing disrupts the biological mechanisms responsible for its regulation

18F-Fluorodeoxyglucose positron emission tomography/computed tomography imaging reveals the protective effect of docosahexaenoic acid on glucose metabolism by reducing brain 27-hydroxycholesterol

Total cholesterol (TC) and the cholesterol oxidation product 27-hydroxycholesterol (27-OHC) are both increased in the elderly. Accumulating evidence has linked 27-OHC to glucose metabolism in the brain, while docosahexaenoic acid (DHA) has been shown to positively regulate the 27-OHC levels. However, it is unclear whether DHA may affect glucose metabolism in the brain by regulating 27-OHC levels. In this study, we hypothesized that DHA supplementation would modulate TC levels and reduce 27-OHC levels, thereby improving brain glucose metabolism in SAMP8 mice. The mice were assigned into the Control group and DHA dietary supplementation group. The study evaluated cholesterol levels, 27-OHC levels, and glucose metabolism in the brain. The results showed that DHA supplementation decreased serum levels of TC, low-density lipoprotein cholesterol (LDL-C), and increased levels of high-density lipoprotein cholesterol (HDL-C); and improved the glucose-corrected standardized uptake value of cortex, hippocampus, and whole brain regions in SAMP8 mice. In conclusion, supplementation of DHA could regulate the cholesterol composition and reduce the level of 27-OHC, thereby improving brain glucose metabolism in SAMP8 mice.

Cholesterol Accumulation Promotes Photoreceptor Senescence and Retinal Degeneration

Purpose

Dysregulated cholesterol metabolism is critical in the pathogenesis of AMD. Cellular senescence contributes to the development of numerous age-associated diseases. In this study, we investigated the link between cholesterol burden and the cellular senescence of photoreceptors.

Methods

Retinas from rod-specific ATP binding cassette subfamily A member 1 (Abca1) and G member 1 (Abcg1) (Abca1/g1-rod/-rod) knockout mice fed with a high-fat diet were analyzed for the signs of cellular senescence. Real-time quantitative PCR and immunofluorescence were used to characterize the senescence profile of the retina and cholesterol-treated photoreceptor cell line (661W). Inducible elimination of p16(Ink4a)-positive senescent cells (INK-ATTAC) mice or the administration of senolytic drugs (dasatinib and quercetin: D&Q) were used to examine the impact of senolytics on AMD-like phenotypes in Abca1/g1-rod/-rod retina.

Results

Increased accumulation of senescent cells as measured by markers of cellular senescence was found in Abca1/g1-rod/-rod retina. Exogenous cholesterol also induced cellular senescence in 661W cells. Selective elimination of senescent cells in Abca1/g1-rod/-rod;INK-ATTAC mice or by administration of D&Q improved visual function, lipid accumulation in retinal pigment epithelium, and Bruch's membrane thickening.

Conclusions

Cholesterol accumulation promotes cellular senescence in photoreceptors. Eliminating senescent photoreceptors improves visual function in a model of retinal neurodegeneration, and senotherapy offers a novel therapeutic avenue for further investigation.

LXR/CD38 activation drives cholesterol-induced macrophage senescence and neurodegeneration via NAD+ depletion

Although dysregulated cholesterol metabolism predisposes aging tissues to inflammation and a plethora of diseases, the underlying molecular mechanism remains poorly defined. Here, we show that metabolic and genotoxic stresses, convergently acting through liver X nuclear receptor, upregulate CD38 to promote lysosomal cholesterol efflux, leading to nicotinamide adenine dinucleotide (NAD+) depletion in macrophages. Cholesterol-mediated NAD+ depletion induces macrophage senescence, promoting key features of age-related macular degeneration (AMD), including subretinal lipid deposition and neurodegeneration. NAD+ augmentation reverses cellular senescence and macrophage dysfunction, preventing the development of AMD phenotype. Genetic and pharmacological senolysis protect against the development of AMD and neurodegeneration. Subretinal administration of healthy macrophages promotes the clearance of senescent macrophages, reversing the AMD disease burden. Thus, NAD+ deficit induced by excess intracellular cholesterol is the converging mechanism of macrophage senescence and a causal process underlying age-related neurodegeneration.

Cholesterol-lowering effects of rhubarb free anthraquinones and their mechanism of action

Rhubarb free anthraquinones (RhA) have significant lipid-regulating activity. However, whether RhA monomers have a role in lipid-regulating and their mechanism of action remains unclear. Based on the cholesterol accumulated HepG2 cell model, the cholesterol-regulating effect of RhA monomers and their combinations was investigated. The expression of sterol-regulatory element binding protein 2 (SREBP2), 3-hydroxy-3-methyl glutaryl coenzyme A reductase (HMGCR) and squalene monooxygenase (SQLE) of the model cells was analyzed to preliminarily explore the mechanism of action. After that, the liposomes of each active RhA monomer were separately prepared with the same lipid materials and the same preparation method so that each monomer has similar or equal bioavailability after oral administration to rats. Finally, the hypercholesterolemic rat model was established, and the effect of active RhA monomers loaded liposomes as well as their combinations on cholesterol-regulating was investigated and their mechanism of action was analyzed. The results showed that aloe-emodin, rhein and emodin were the main cholesterol-regulating components of RhA, and the combination of rhein and emodin showed significant cholesterol-lowering effect, which may be related to the expression of SREBP2, HMGCR and SQLE in the rat liver.

Associations between lipid profiles and late-life cognitive impairment among oldest-old and centenarian adults

Dyslipidemia and cognitive impairment are common among old adults and the occurrence of them rises exponentially with increasing age. Evidences of the relationships between serum lipids and cognitive impairment are inconsistent or equivocal among older adults. This study aimed to investigate the associations between lipid profiles and late-life cognitive impairment among oldest-old and centenarian adults. In this cross-sectional study, serum lipids were biochemically measured among 606 oldest-old adults and 653 centenarians, and cognitive function was evaluated using mini-mental state examination (MMSE). Multivariate linear and logistic regression analyses were performed to explore the associations between serum lipids and cognitive impairment. Results showed participants with cognitive impairment had lower total cholesterol (TC) levels compared with those without cognitive impairment (p < 0.05). TC levels were positively associated with MMSE (p < 0.05). Furthermore, a negative association was observed between TC levels and cognitive impairment (p for trend = 0.002). This negative association remained statistically significant after adjusting for confounders (p for trend = 0.028). These results suggested that older adults with higher TC levels were likely to have better cognitive function. Taking immoderate cholesterol-lowering drugs among older adults is questionable and requires investigation, and cognitive performance of old adults with lower TC levels deserves more attention.

Computationally Modelling Cholesterol Metabolism and Atherosclerosis

Cardiovascular disease (CVD) is the leading cause of death globally. The underlying pathological driver of CVD is atherosclerosis. The primary risk factor for atherosclerosis is elevated low-density lipoprotein cholesterol (LDL-C). Dysregulation of cholesterol metabolism is synonymous with a rise in LDL-C. Due to the complexity of cholesterol metabolism and atherosclerosis mathematical models are routinely used to explore their non-trivial dynamics. Mathematical modelling has generated a wealth of useful biological insights, which have deepened our understanding of these processes. To date however, no model has been developed which fully captures how whole-body cholesterol metabolism intersects with atherosclerosis. The main reason for this is one of scale. Whole body cholesterol metabolism is defined by macroscale physiological processes, while atherosclerosis operates mainly at a microscale. This work describes how a model of cholesterol metabolism was combined with a model of atherosclerotic plaque formation. This new model is capable of reproducing the output from its parent models. Using the new model, we demonstrate how this system can be utilized to identify interventions that lower LDL-C and abrogate plaque formation.

The Effect of Plastic-Related Compounds on Transcriptome-Wide Gene Expression on CYP2C19-Overexpressing HepG2 Cells

In recent years, plastic and especially microplastic in the oceans have caused huge problems to marine flora and fauna. Recently, such particles have also been detected in blood, breast milk, and placenta, underlining their ability to enter the human body, presumably via the food chain and other yet-unknown mechanisms. In addition, plastic contains plasticizers, antioxidants, or lubricants, whose impact on human health is also under investigation. At the cellular level, the most important enzymes involved in the metabolism of xenobiotic compounds are the cytochrome P450 monooxygenases (CYPs). Despite their extensive characterization in the maintenance of cellular balance, their interactions with plastic and related products are unexplored. In this study, the possible interactions between several plastic-related compounds and one of the most important cytochromes, CYP2C19, were analyzed. By applying virtual compound screening and molecular docking to more than 1000 commercially available plastic-related compounds, we identified candidates that are likely to interact with this protein. A growth inhibition assay confirmed their cytotoxic activity on a CYP2C19-transfected hepatic cell line. Subsequently, we studied the effect of the selected compounds on the transcriptome-wide gene expression level by conducting RNA sequencing. Three candidate molecules were identified, i.e., 2,2'-methylene bis(6-tert-butyl-4-methylphenol), 1,1-bis(3,5-di-tert-butyl-2-hydroxyphenyl) ethane, and 2,2'-methylene bis(6-cyclohexyl-4-methylphenol)), which bound with a high affinity to CYP2C19 in silico. They exerted a profound cytotoxicity in vitro and interacted with several metabolic pathways, of which the 'cholesterol biosynthesis process' was the most affected. In addition, other affected pathways involved mitosis, DNA replication, and inflammation, suggesting an increase in hepatotoxicity. These results indicate that plastic-related compounds could damage the liver by affecting several molecular pathways.

The Roles of Lipid Metabolism in the Pathogenesis of Chronic Diseases in the Elderly

Lipid metabolism plays crucial roles in cellular processes such as hormone synthesis, energy production, and fat storage. Older adults are at risk of the dysregulation of lipid metabolism, which is associated with progressive declines in the physiological function of various organs. With advancing age, digestion and absorption commonly change, thereby resulting in decreased nutrient uptake. However, in the elderly population, the accumulation of excess fat becomes more pronounced due to a decline in the body's capacity to utilize lipids effectively. This is characterized by enhanced adipocyte synthesis and reduced breakdown, along with diminished peripheral tissue utilization capacity. Excessive lipid accumulation in the body, which manifests as hyperlipidemia and accumulated visceral fat, is linked to several chronic lipid-related diseases, including cardiovascular disease, type 2 diabetes, obesity, and nonalcoholic fatty liver disease. This review provides a summary of the altered lipid metabolism during aging, including lipid digestion, absorption, anabolism, and catabolism, as well as their associations with age-related chronic diseases, which aids in developing nutritional interventions for older adults to prevent or alleviate age-related chronic diseases.

The Association of Dietary Cholesterol from Egg Consumption on Cardiovascular Diseases Risk Varies from Person to Person

The public and scientists remain skeptical about egg consumption, given that cardiovascular diseases (CVDs) are the leading causes of death in worldwide. This review mainly explained the recurrence of contradictory conclusions about relationships between egg consumption and CVD risk and discussed effects of egg cholesterol intake on cholesterol homeostasis. Factors including individual health status and cholesterol sensitivity, dietary pattern, region, and race should be distinguished when understanding generalized conclusions. Identified compensatory mechanisms in response to dietary cholesterol and the resulting balance in cholesterol biosynthesis, absorption, and efflux supported the view that moderate egg consumption had no substantial overall impacts on cholesterol homeostasis in healthy people. Excessive cholesterol intake is not recommended in individuals with distempered metabolism. More than cholesterol metabolism, impacts of egg consumption as a part of overall diet on CVD risk should be considered from aspects of nutrient intake, lipid metabolism, and energy supply in the future.

Azelastine a potent antihistamine agent, as hypolipidemic and modulator for aortic calcification in diabetic hyperlipidemic rats model

AIM

Our study aimed to illustrate the effect of the antihistaminic drug azelastine on aortic calcification in diabetic hyperlipidemic (DH) rats along with the underlying molecular mechanism.

METHODS

Twenty-four male albino Wistar rats were categorised into four groups. One group received normal rodent chow (normal group), while the other groups were rendered diabetic and hyperlipidemic; one received no drugs and served as a positive control while the other two groups received either azelastine (4 mg/kg) or 10-dehydrogingerdione (10 mg/kg) orally and daily for 8 weeks.

RESULTS

Azelastine significantly reduced blood glucose, HbA1c and serum ALP, OCN, downregulated apo B, improved the lipid profile (LDL-c decrease and HDL-c increase), attenuated calcium deposition and aortic calcification as compared to control group. 10-DHGD showed comparatively lower effect.

CONCLUSION

Anti-calcifying effect of azelastine might be related to upregulation of apo A (HDL-c) and downregulation of apo B mRNA expression indeed good modulator of aortic calcification.

IMPACT STATEMENT

Many studies have indicated that high-density lipoprotein-cholesterol (HDL-c) is inversely correlated with atherosclerotic plaque progression and could reduce cardiovascular disease risk. An anti-calcifying effect of HDL-c has been reported and targeting this lipoprotein may therefore be a valuable approach to vascular calcification control. Azelastine is a selective H1 antagonist that was identified to increase mRNA expression of apolipoprotein A. This encouraged us to investigate the effect of azelastine on lipid profile and markers of aortic calcification in DH rats. Our findings showed that azelastine ameliorated aortic calcification and increased apoA expression along with a decline in apo B. This may represent the underlying mechanism while the histopathological findings offered a significant support to the collected biochemical data.

Dietary restriction and ageing: Recent evolutionary perspectives

Dietary restriction (DR) represents one of the most robust interventions for extending lifespan. It is not known how DR increases lifespan. The prevailing evolutionary hypothesis suggests the DR response redirects metabolic resources towards somatic maintenance at the expense of investment in reproduction. Consequently, DR acts as a proximate mechanism which promotes a pro-longevity phenotype. This idea is known as resource reallocation. However, growing findings suggest this paradigm could be incomplete. It has been argued that during DR it is not always possible to identify a trade-off between reproduction and lifespan. It is also suggested the relationship between reproduction and somatic maintenance can be uncoupled by the removal or inclusion of specific nutrients. These findings have created an imperative to re-explore the nexus between DR and evolutionary theory. In this review I will address this evolutionary conundrum. My overarching objectives are fourfold: (1) to outline some of the evidence for and against resource reallocation; (2) to examine recent findings which have necessitated a theoretical re-evaluation of the link between life history theory and DR; (3) to present alternatives to the resource reallocation model; (4) to present emerging variables which potentially influence how DR effects evolutionary trade-offs.

Proteomic Signatures of the Serological Response to Influenza Vaccination in a Large Human Cohort Study

The serological response to the influenza virus vaccine is highly heterogeneous for reasons that are not entirely clear. While the impact of demographic factors such as age, body mass index (BMI), sex, prior vaccination and titer levels are known to impact seroconversion, they only explain a fraction of the response. To identify signatures of the vaccine response, we analyzed 273 protein levels from 138 serum samples of influenza vaccine recipients (2019-2020 season). We found that levels of proteins functioning in cholesterol transport were positively associated with seroconversion, likely linking to the known impact of BMI. When adjusting seroconversion for the demographic factors, we identified additional, unexpected signatures: proteins regulating actin cytoskeleton dynamics were significantly elevated in participants with high adjusted seroconversion. Viral strain specific analysis showed that this trend was largely driven by the H3N2 strain. Further, we identified complex associations between adjusted seroconversion and other factors: levels of proteins of the complement system associated positively with adjusted seroconversion in younger participants, while they were associated negatively in the older population. We observed the opposite trends for proteins of high density lipoprotein remodeling, transcription, and hemostasis. In sum, careful integrative modeling can extract new signatures of seroconversion from highly variable data that suggest links between the humoral response as well as immune cell communication and migration.

Liuwei Dihuang Decoction Alleviates Cognitive Dysfunction in Mice With D-Galactose-Induced Aging by Regulating Lipid Metabolism and Oxidative Stress via the Microbiota-Gut-Brain Axis

Background

Aging is an important cause of cognitive dysfunction. Liuwei Dihuang decoction (LW), a commonly applied Chinese medicine formula, is widely used for the treatment of aging-related diseases in China. Previously, LW was confirmed to be effective in prolonging life span and reducing oxidative stress in aged mice. Unfortunately, the underlying mechanism of LW remains unclear. The aim of this study was to interpret the mechanism by which LW alleviates cognitive dysfunction related to aging from the perspective of the microbiota-gut-brain axis.

Method

All C57BL/6 mice (n = 60) were randomly divided into five groups: the control, model, vitamin E (positive control group), low-dose LW and high-dose LW groups (n = 12 in each group). Except for those in the control group, D-galactose was subcutaneously injected into mice in the other groups to induce the aging model. The antiaging effect of LW was evaluated by the water maze test, electron microscopy, 16S rRNA sequencing, combined LC–MS and GC–MS metabolomics, and ELISA.

Results

Liuwei Dihuang decoction ameliorated cognitive dysfunction and hippocampal synaptic ultrastructure damage in aging mice. Moreover, LW decreased Proteobacteria abundance and increased gut microbiota diversity in aging mice. Metabolomic analysis showed that LW treatment was associated with the significantly differential abundance of 14 metabolites, which were mainly enriched in apelin signaling, sphingolipid metabolism, glycerophospholipid and other metabolic pathways. Additionally, LW affected lipid metabolism and oxidative stress in aging mice. Finally, we also found that LW-regulated microbial species such as Proteobacteria and Fibrobacterota had potential relationships with lipid metabolism, oxidative stress and hippocampal metabolites.

Conclusion

In brief, LW improved cognitive function in aging mice by regulating lipid metabolism and oxidative stress through restoration of the homeostasis of the microbiota-gut-brain axis.

How do lipids influence risk of violence, self-harm and suicidality in people with psychosis? A systematic review

OBJECTIVES

Low cholesterol has been linked with violent and suicidal behaviour in people with schizophrenia. This association, if consistently present, may be a promising biological marker that could assist clinicians in decision making regarding risk and treatment. We conducted a systematic review to assess whether there is a reliable association between lipid profile (total cholesterol, high- and low-density lipoprotein cholesterol, and triglycerides) and aggression, self-harm or suicide in people with schizophrenia, and whether effects are similar in males and females.

METHOD

Relevant databases were searched to identify primary research studies (up to November 2020) that (1) involved adults (some samples also included 16- to 18-year olds) with a confirmed diagnosis of schizophrenia, schizoaffective disorder or psychosis; and (2) included a standardised assessment of verbal aggression, physical aggression against objects, physical aggression against self (including suicide) or others. The search yielded 23 studies eligible for inclusion following a quality appraisal.

RESULTS

Suicidality was the most commonly assessed subtype of aggression (20 studies). For suicidality, about half the studies, including the study with the largest sample size, found a link with total cholesterol. An association between low total cholesterol and violence towards others was found in six of nine studies that investigated this. The evidence for a link with violence was the strongest for total cholesterol, followed by low-density lipoprotein cholesterol and high-density lipoprotein cholesterol, and the weakest for triglycerides. Only a few studies investigated sex differences and yielded mixed evidence. Studies focussed on self-harm as well as involving females in forensic settings were lacking.

CONCLUSION

There is encouraging evidence of an association between low total cholesterol and aggression towards others as well as suicidality in schizophrenia. Future studies should systematically explore this association in people with schizophrenia who have a significant history of violence, suicidality and self-harm, both inpatients and community, and also investigate underlying mechanisms.

Oxysterols are potential physiological regulators of ageing

Delaying and even reversing ageing is a major public health challenge with a tremendous potential to postpone a plethora of diseases including cancer, metabolic syndromes and neurodegenerative disorders. A better understanding of ageing as well as the development of innovative anti-ageing strategies are therefore an increasingly important field of research. Several biological processes including inflammation, proteostasis, epigenetic, oxidative stress, stem cell exhaustion, senescence and stress adaptive response have been reported for their key role in ageing. In this review, we describe the relationships that have been established between cholesterol homeostasis, in particular at the level of oxysterols, and ageing. Initially considered as harmful pro-inflammatory and cytotoxic metabolites, oxysterols are currently emerging as an expanding family of fine regulators of various biological processes involved in ageing. Indeed, depending of their chemical structure and their concentration, oxysterols exhibit deleterious or beneficial effects on inflammation, oxidative stress and cell survival. In addition, stem cell differentiation, epigenetics, cellular senescence and proteostasis are also modulated by oxysterols. Altogether, these data support the fact that ageing is influenced by an oxysterol profile. Further studies are thus required to explore more deeply the impact of the "oxysterome" on ageing and therefore this cholesterol metabolic pathway constitutes a promising target for future anti-ageing interventions.

Pharmacological mechanism of Shenlingbaizhu formula against experimental colitis

BACKGROUND

Ulcerative colitis (UC) is a type of inflammatory bowel disease (IBD) characterized by an overactive immune response and destruction of the colorectal epithelium with intricate pathological factors. Shenlingbaizhu (SLBZ) formula, included in the Chinese Pharmacopoeia 2020, has been widely utilized to treat UC.

PURPOSE

The present study was designed to uncover the underlying molecular mechanisms of SLBZ formula against UC.

METHODS

A murine model of experimental colitis was established by orally feeding 2% dextran sodium sulfate (DSS) to mice for 7 days, followed by SLBA treatment for the next 15 days. Network pharmacology analysis was performed to predict the pharmacological mechanisms. High-throughput 16S rRNA sequencing integrated with liquid chromatography-mass spectrometry (LC-MS) was conducted on mouse stool in order to determine alterations in the composition of the intestinal microbiota and metabolites. Western blotting, immunofluorescence, and flow cytometry were performed to examine the anti-inflammatory role of SLBZ.

RESULTS

DSS treatment induced experimental colitis, and this induction was alleviated by SLBZ treatment, as evidenced by rescued pathological symptoms in the experimental colitis mouse groups. Network pharmacology analysis showed that SLBZ-target genes were enriched in pathogen-induced infectious and inflammatory pathways, as well as neoplastic processes. SLBZ administration also modulated the gut microbiota composition and metabolic profiles of experimental colitis mice and alleviated the progression of experimental colitis. We further showed via in-vitro experiments that SLBZ suppressed macrophage (Mφ) transition to pro-inflammatory phenotype (M1), rescued tumor necrosis factor-α (TNFα)-induced pyroptosis of intestinal organoids (IOs), and decreased the recruitment of Mφs by epithelial cells.

CONCLUSION

SLBZ formula is an effective treatment for murine colitis and showed a stronger therapeutic capacity than melasazine. The pharmacological mechanisms of SLBZ involve the re-establishment of an anti-inflammatory milieu and healthy microbiome, which favors mucosal healing.

Epigallocatechin-3-Gallate (EGCG): New Therapeutic Perspectives for Neuroprotection, Aging, and Neuroinflammation for the Modern Age

Alzheimer’s and Parkinson’s diseases are the two most common forms of neurodegenerative diseases. The exact etiology of these disorders is not well known; however, environmental, molecular, and genetic influences play a major role in the pathogenesis of these diseases. Using Alzheimer’s disease (AD) as the archetype, the pathological findings include the aggregation of Amyloid Beta (Aβ) peptides, mitochondrial dysfunction, synaptic degradation caused by inflammation, elevated reactive oxygen species (ROS), and cerebrovascular dysregulation. This review highlights the neuroinflammatory and neuroprotective role of epigallocatechin-3-gallate (EGCG): the medicinal component of green tea, a known nutraceutical that has shown promise in modulating AD progression due to its antioxidant, anti-inflammatory, and anti-aging abilities. This report also re-examines the current literature and provides innovative approaches for EGCG to be used as a preventive measure to alleviate AD and other neurodegenerative disorders.

Population Genomics of Megalobrama Provides Insights into Evolutionary History and Dietary Adaptation

Simple Summary

Megalobrama is the economically most important freshwater fish genus in China. In recent years, germplasm resources of Megalobrama have been depleting as a result of environmental degradation and artificial factors. In this study, we established the whole genome database of Megalobrama populations using the whole genome re-sequencing technology, explored population genetic structure, and inferred comprehensive evolutionary relationships using principal component analysis and population structure analysis. Furthermore, employing selective sweep analysis, we identified candidate genes related to variations in feeding habits, revealing the molecular mechanisms of environmental adaptability in Megalobrama populations. Taken together, this study describes the population history and genetic diversity of Megalobrama populations and also the molecular mechanisms likely involved their environmental adaptability. These findings will make a substantial contribution to conservation and utilization of Megalobrama germplasm resources.

Abstract

Megalobrama, a genus of cyprinid fish, is an economically important freshwater fish widely distributed in major waters of China. Here, we report the genome resequencing of 180 Megalobrama fish including M. amblycephala, M. skolkovii, M. hoffmanni, and M. pellegrini. Population structure indicated that geographically divergent Megalobrama populations were separated into six subgroups. A phylogenetic tree showed that M. skolkovii was more closely related to M. pellegrini than other species and M. hoffmanni was clustered apart from other Megalobrama species, showing a high nucleotide diversity in geographic groups. Treemix validated gene flow from M. amblycephala to M. skolkovii, suggesting that introgression may provide an important source of genetic variation in the M. skolkovii populations. According to the demographic history analysis, it is speculated that Megalobrama might have been originally distributed in the Pearl River with some spread to Hainan Island and northern China due to lower sea levels during the glacial period. Whole-genome selective sweeps analysis demonstrated that M. amblycephala likely developed an enhanced energy metabolism mostly through fatty acid degradation pathways whereas M. hoffmanni possibly regulate lipid absorption via the cholesterol metabolism pathway. Taken together, this study provides a valuable genomic resource for future genetic investigations aiming to improve genome-assisted breeding of Megalobrama species.

Mathematical Models for Cholesterol Metabolism and Transport

Cholesterol is an essential component of eukaryotic cellular membranes. It is also an important precursor for making other molecules needed by the body. Cholesterol homeostasis plays an essential role in human health. Having high cholesterol can increase the chances of getting heart disease. As a result of the risks associated with high cholesterol, it is imperative that studies are conducted to determine the best course of action to reduce whole body cholesterol levels. Mathematical models can provide direction on this. By examining existing models, the suitable reactions or processes for drug targeting to lower whole-body cholesterol can be determined. This paper examines existing models in the literature that, in total, cover most of the processes involving cholesterol metabolism and transport, including: the absorption of cholesterol in the intestine; the cholesterol biosynthesis in the liver; the storage and transport of cholesterol between the intestine, the liver, blood vessels, and peripheral cells. The findings presented in these models will be discussed for potential combination to form a comprehensive model of cholesterol within the entire body, which is then taken as an in-silico patient for identifying drug targets, screening drugs, and designing intervention strategies to regulate cholesterol levels in the human body.

The accelerated aging phenotype: The role of race and social determinants of health on aging

The pursuit to discover the fundamental biology and mechanisms of aging within the context of the physical and social environment is critical to designing interventions to prevent and treat its complex phenotypes. Aging research is critically linked to understanding health disparities because these inequities shape minority aging, which may proceed on a different trajectory than the overall population. Health disparities are characteristically seen in commonly occurring age-associated diseases such as cardiovascular and cerebrovascular disease as well as diabetes mellitus and cancer. The early appearance and increased severity of age-associated disease among African American and low socioeconomic status (SES) individuals suggests that the factors contributing to the emergence of health disparities may also induce a phenotype of 'premature aging' or 'accelerated aging' or 'weathering'. In marginalized and low SES populations with high rates of early onset age-associated disease the interaction of biologic, psychosocial, socioeconomic and environmental factors may result in a phenotype of accelerated aging biologically similar to premature aging syndromes with increased susceptibility to oxidative stress, premature accumulation of oxidative DNA damage, defects in DNA repair and higher levels of biomarkers of oxidative stress and inflammation. Health disparities, therefore, may be the end product of this complex interaction in populations at high risk. This review will examine the factors that drive both health disparities and the accelerated aging phenotype that ultimately contributes to premature mortality.

Low baseline plasma PCSK9 level is associated with good clinical outcomes of immune checkpoint inhibitors in advanced non‐small cell lung cancer

Background

Methods

Results

Conclusions

Age-related blood biochemical changes (lipid metabolism) in healthy young and mature men living under the North conditions

Metabolic disorders (dyslipidemias) are currently crucial since they develop cardiovascular diseases. The work was aimed at studying age dynamics and its correlation with severity of dyslipidemia in basic lipid metabolism variables (in different age groups).

MATERIALS AND METHODS

Examinees were Caucasians born and permanently residing in Magadan region: 55 mature men and 147 young men (mean ages were 36.8±0.8 and 18.7±0.8 yr, respectively). Blood serum lipid metabolism was examined by colorimetric and photometric method using AU 680 (Beckman Coulter, USA).

RESULTS

The data of obtained lipidogram showed dependence of rise in all indicators on subjective older age with higher percentage of dyslipidemia and increase in calculated indices reflecting degree of the lipid profile atherogenicity.

CONCLUSION

Overall, the North study revealed a safer lipid profile in group of younger men, while biochemical picture of older residents demonstrated increased values. Lipid atherogenicity is a very alarming factor in developing cardiovascular diseases, and a predictor of risks for metabolic syndrome.

Modeling cholesterol metabolism and atherosclerosis

Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of morbidity and mortality among Western populations. Many risk factors have been identified for ASCVD; however, elevated low-density lipoprotein cholesterol (LDL-C) remains the gold standard. Cholesterol metabolism at the cellular and whole-body level is maintained by an array of interacting components. These regulatory mechanisms have complex behavior. Likewise, the mechanisms which underpin atherogenesis are nontrivial and multifaceted. To help overcome the challenge of investigating these processes mathematical modeling, which is a core constituent of the systems biology paradigm has played a pivotal role in deciphering their dynamics. In so doing models have revealed new insights about the key drivers of ASCVD. The aim of this review is fourfold; to provide an overview of cholesterol metabolism and atherosclerosis, to briefly introduce mathematical approaches used in this field, to critically discuss models of cholesterol metabolism and atherosclerosis, and to highlight areas where mathematical modeling could help to investigate in the future. This article is categorized under: Cardiovascular Diseases > Computational Models.

Anticholesterolemic Activity of Three Vegetal Extracts (Artichoke, Caigua, and Fenugreek) and Their Unique Blend

Hepatic-related diseases, in particular hyperlipidemia and hypercholesterolemia, are a thorn on the side of the national health institutes around the globe. Indeed, liver lipid and cholesterol dysregulation could lead to atherosclerotic plaque formation and cardiovascular diseases. Currently, statin administration and monacolin K consumption are the main therapies proposed to counter this alarming connection, but relevant side effects are known. To overcome this issue, safe nutraceutical formulations and/or vegetal extracts, endowed with anticholesterolemic activity, could be instrumental in hypercholesterolemia prevention and treatment. In the present work, the anticholesterolemic efficacy of three vegetal extracts used in traditional medicine (artichoke, caigua, and fenugreek), their unique blend (ACFB), and the monacolin K-containing red yeast extract (RYR), was investigated with an in vitro approach based on hepatic cell line HepG2. The impact on cholesterol of the three extracts, their blend, and RYR were investigated by determining hepatocyte total and free cholesterol and bile acids biosynthesis. According to our results, the anticholesterolemic activity of the vegetal extracts was confirmed, and a novel choleretic activity of caigua extract was evidenced. ACFB showed to be safer than RYR while showing a similar effect on total and free cholesterol and bile acids synthesis compared to it. The anticholesterolemic activity of the blend was obtained with lower vegetal extract concentrations compared with the single vegetal extract, potentially indicating an additive effect between the extracts. In conclusion, the vegetal extracts and their blend, ACFB, are safe and are endowed with anticholesterolemic activity, potentially providing complementary therapies to the statin-based ones for hyperlipidemia and hypercholesterolemia-related complications.

Lipid lowering in patients 75 years and older

More than twenty years ago, knowledge about the importance of cholesterol absorption and the potential therapeutic effect of its inhibition led to the discovery and clinical application of the first and only cholesterol absorption inhibitor to date – ezetimibe. Since then, ezetimibe has become a well-recognized player in lipid-lowering therapy. Recent findings of IMPROVE-IT and EWTOPIA 75 imply that elderly patients over the age of 75 years in particular benefit from ezetimibe. This review summarizes the evidence, discusses the possible underlying pathophysiological mechanisms and calls for a change in future dyslipidemia guidelines.

First case series of Polish patients with cerebrotendinous xanthomatosis and systematic review of cases from the 21st century

Cerebrotendinous xanthomatosis (CTX) is an inborn error of metabolism caused by recessive variants in the cytochrome P450 CYP27A1 gene. CTX is said to manifest with childhood-onset chronic diarrhea and the classic triad of juvenile-onset cataracts, Achilles tendons xanthomas, and progressive ataxia. It is currently one of the few inherited neurometabolic disorders amenable to a specific treatment. The diagnosis may be significantly delayed resulting in permanent neurological impairment. A retrospective review of the clinical characteristics and diagnostic findings in case series of six Polish patients with CTX. Additional retrospective review of symptoms and pathogenic variants of 568 CTX available cases and case series from the past 20 years. To the best of our knowledge, this is the widest review of CTX cases reported in years 2000-2021. We report the largest cohort of Polish patients ever published, with the identification of two hot-spot mutations. During the review of available 568 cases, we found significant differences in the clinical phenotypes and the localization of variants within the gene between Asian and non-Asian populations. These findings may facilitate molecular testing in the Polish and Asian populations. Invariably better screening for CTX and wider awareness is needed.

Seasonal Consumption of Cherries from Different Origins Affects Metabolic Markers and Gene Expression of Lipogenic Enzymes in Rat Liver: A Preliminary Study

The phytochemical composition of fruits, especially polyphenols, depends on the environmental conditions under which these fruits are cultivated and the agronomic practices followed. Therefore, the consumption of fruits from different origins, with different polyphenol signatures, could have differential effects on health. In addition, recent studies have shown that variation in the biological rhythms due to changes in the photoperiod in the different seasons differentially affect the metabolism in animal models, thus conditioning their response to food consumption. Considering all, this article evaluates the effects of consumption of sweet cherry from different sources, local (LC) and non-local (nLC), on plasma metabolic parameters and the gene expression of key enzymes of lipid metabolism in Fischer 344 rats under photoperiods simulating different seasons. Animals were classified into three photoperiods (L6, L12 and L18) and three treatments (LC, nLC and VH). Both the photoperiod and the treatments significantly affected the evaluated parameters. An effect of the photoperiod on triacylglycerides, non-esterified fatty acids and the mRNA concentration of crucial enzymes from the hepatic lipid metabolism was observed. Furthermore, the consumption of fruit in L12 lowered blood glucose, while the different treatments affected the hepatic expression of genes related with lipidic enzymes.

Hepatocyte activity of the cholesterol sensor smoothened regulates cholesterol and bile acid homeostasis in mice

Cellular cholesterol is regulated by at least two transcriptional mechanisms involving sterol-regulatory-element-binding proteins (SREBPs) and liver X receptors (LXRs). Although SREBP and LXR pathways are the predominant mechanisms that sense cholesterol in the endoplasmic reticulum and nucleus to alter sterol-regulated gene expression, evidence suggests cholesterol in plasma membrane can be sensed by proteins in the Hedgehog (Hh) pathway which regulate organ self-renewal and are a morphogenic driver during embryonic development. Cholesterol interacts with the G-protein-coupled receptor Smoothened (Smo), which impacts downstream Hh signaling. Although evidence suggests cholesterol influences Hh signaling, it is not known whether Smo-dependent sterol sensing impacts cholesterol homeostasis in vivo. We examined dietary-cholesterol-induced reorganization of whole-body sterol and bile acid (BA) homeostasis in adult mice with inducible hepatocyte-specific Smo deletion. These studies demonstrate Smo in hepatocytes plays a regulatory role in sensing and feedback regulation of cholesterol balance driven by excess dietary cholesterol.

The relationship of mesencephalic astrocyte-derived neurotrophic factor with hyperlipidemia in patients with or without type 2 diabetes mellitus

PURPOSE

This study was conducted to determine the relationship between mesencephalic astrocyte-derived neurotrophic factor (MANF) and lipid metabolism with or without type 2 diabetes mellitus (T2DM).

METHODS

Human serum samples were collected from 58 normal controls (NC), 40 subjects with hyperlipidemia (HLD) without T2DM, and 42 subjects with HLD and T2DM. Their MANF levels were detected using an enzyme-linked immunosorbent assay (ELISA). Subgroup analysis was performed in the group with HLD and T2DM based on fasting blood glucose (FBG) > 8.22 vs. FBG ≤ 8.22. Furthermore, the relationship between MANF levels and lipid indices was analyzed.

RESULTS

Serum MANF levels were found to be significantly higher in the HLD group, both with and without T2DM (5.62 (3.59-7.11) and 4.21 (2.87-6.11)), both P < 0.001, than in the NC (2.81(1.81-4.01). MANF levels were higher in those with FBG > 8.22 than that in those with FBG ≤ 8.22. In addition, in the HLD without T2DM group, MANF levels were negatively correlated with total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and age, while LDL-C and age were independently related to MANF levels. The area under the curve (AUC) in the ROC analysis of MANF for the diagnosis of HLD without T2DM and HLD with T2DM was 0.709 and 0.841, respectively (P < 0.001).

CONCLUSION

Serum MANF levels increased in the HLD with or without T2DM groups and was associated with lipid and glucose metabolism. MANF may be a useful marker for predicting the development of dyslipidemia in T2DM.

The Interdependency and Co-Regulation of the Vitamin D and Cholesterol Metabolism

Vitamin D and cholesterol metabolism overlap significantly in the pathways that contribute to their biosynthesis. However, our understanding of their independent and co-regulation is limited. Cardiovascular disease is the leading cause of death globally and atherosclerosis, the pathology associated with elevated cholesterol, is the leading cause of cardiovascular disease. It is therefore important to understand vitamin D metabolism as a contributory factor. From the literature, we compile evidence of how these systems interact, relating the understanding of the molecular mechanisms involved to the results from observational studies. We also present the first systems biology pathway map of the joint cholesterol and vitamin D metabolisms made available using the Systems Biology Graphical Notation (SBGN) Markup Language (SBGNML). It is shown that the relationship between vitamin D supplementation, total cholesterol, and LDL-C status, and between latitude, vitamin D, and cholesterol status are consistent with our knowledge of molecular mechanisms. We also highlight the results that cannot be explained with our current knowledge of molecular mechanisms: (i) vitamin D supplementation mitigates the side-effects of statin therapy; (ii) statin therapy does not impact upon vitamin D status; and critically (iii) vitamin D supplementation does not improve cardiovascular outcomes, despite improving cardiovascular risk factors. For (iii), we present a hypothesis, based on observations in the literature, that describes how vitamin D regulates the balance between cellular and plasma cholesterol. Answering these questions will create significant opportunities for advancement in our understanding of cardiovascular health.

Novel Metabolic Regulation of Bile Acid Responses to Low Cholesterol in Whole-Grain-Diet-Fed Mice

Hypercholesterolemia is a major risk factor for chronic metabolic diseases. Nevertheless, a whole-grain diet could ameliorate this issue in a number of ways, including by regulating bile acid metabolism. However, the potential mechanism is unclear. The aim of the current study is to explore the effects of whole-grain diets (brown rice diet and whole wheat diet) on bile acid homeostasis. After intervention for 8 weeks in mouse model, whole-grain diets showed reduced feed conversion ratio, and the lipid levels (total cholesterol (TC) and triglycerides (TG)) were also meliorated in the serum and liver of mice. Moreover, whole-grain diets reduced the expression of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) (cholesterol synthesis) in the liver of mice. Interestingly, whole-grain diets not only promoted the mRNA expressions of low-density lipoprotein receptor (LDLR), ATP binding cassette transporter G1 (ABCG1), and scavenger receptor class B type I (SR-BI) (reverse cholesterol transport) but also facilitated the expressions of cytochrome P450, family 7, subfamily a, polypeptide 1 (CYP7a1) and cytochrome P450, family 27, subfamily a, polypeptide 1 (CYP27a1) (bile acid synthesis). Further study found that whole-grain diets promoted intestinal bile acid reabsorption and reduced bile acid excretion. Our study provided a novel metabolic regulation of bile acids in response to reduced cholesterol levels induced by whole-grain diets.

Extra Virgin Olive Oil Prevents the Age-Related Shifts of the Distribution of HDL Subclasses and Improves Their Functionality

High-density lipoproteins (HDL) maintain cholesterol homeostasis through the role they play in regulating reverse cholesterol transport (RCT), a process by which excess cholesterol is transported back to the liver for elimination. However, RCT can be altered in the presence of cardiovascular risk factors, such as aging, which contributes to the increase in the incidence of cardiovascular diseases (CVD). The present study was aimed at investigating the effect of extra virgin olive oil (EVOO) intake on the cholesterol efflux capacity (CEC) of HDL, and to elucidate on the mechanisms by which EVOO intake improves the anti-atherogenic activity of HDL. A total of 84 healthy women and men were enrolled and were distributed, according to age, into two groups: 27 young (31.81 ± 6.79 years) and 57 elderly (70.72 ± 5.6 years) subjects. The subjects in both groups were given 25 mL/d of extra virgin olive oil (EVOO) for 12 weeks. CEC was measured using J774 macrophages radiolabeled with tritiated cholesterol ((3H) cholesterol). HDL subclass distributions were analyzed using the Quantimetrix Lipoprint® system. The HDL from the elderly subjects exhibited a lower level of CEC, at 11.12% (p < 0.0001), than the HDL from the young subjects. The CEC of the elderly subjects returned to normal levels following 12 weeks of EVOO intake. An analysis of the distribution of HDL subclasses showed that HDL from the elderly subjects were composed of lower levels of large HDL (L-HDL) (p < 0.03) and higher levels of small HDL (S-HDL) (p < 0.002) compared to HDL from the young subjects. A multiple linear regression analysis revealed a positive correlation between CEC and L-HDL levels (r = 0.35 and p < 0.001) as well as an inverse correlation between CEC and S-HDL levels (r = -0.27 and p < 0.01). This correlation remained significant even when several variables, including age, sex, and BMI as well as low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and glucose levels (β = 0.28, p < 0.002, and β = 0.24, p = 0.01) were accounted for. Consuming EVOO for 12 weeks modulated the age-related difference in the distribution of HDL subclasses by reducing the level of S-HDL and increasing the level of intermediate-HDL/large-HDL (I-HDL/L-HDL) in the elderly subjects. The age-related alteration of the CEC of HDL was due, in part, to an alteration in the distribution of HDL subclasses. A diet enriched in EVOO improved the functionality of HDL through an increase in I-HDL/L-HDL and a decrease in S-HDL.

Cardiovascular Health in Individuals with Exceptional Longevity Residing in Arkansas

Cardiovascular disease is a common comorbidity associated with an aging population. However, there is a unique group of individuals whose age-defying qualities are still being investigated. This retrospective chart review analyzed various cardiac and metabolic health parameters to characterize the prevalence of heart failure and metabolic derangements in individuals aged 90 years old or older in central Arkansas. Only 236 of the 291 patients in our study cohort had blood pressures recorded. Of these, 50% had systolic blood pressures ≥140 mmHg. Additionally, 77% had pulse pressures ≥50 mmHg. Of the 96 patients with BNP data, 44% had values ≥300 pg/mL. There was a slight positive correlation between aging and HDL cholesterol, while there was a negative correlation between aging and both total cholesterol and LDL cholesterol. A majority of our patients had both elevated systolic blood pressures and elevated pulse pressures. A majority also had high BNP values, indicative of some degree of heart failure. Additionally, atrial fibrillation was a common arrhythmia identified on EKG. However, these oldest of the old patients had fewer documented metabolic derangements. These findings lay important groundwork for further investigation into lifestyle and genetic components that allow them to live exceptionally long with such comorbidities.

Dyslipidemia and prevention of atherosclerotic cardiovascular disease in the elderly

The atherosclerotic cardiovascular disease (ASCVD) represents the leading cause of death and disability in the elderly. The study of atherosclerosis and the strategies to control ASCVD are evolving. All strategies emphasize the need to lower LDL cholesterol (LDL-C) through an appropriate lifestyle and the use of lipid-lowering drugs, mainly statins. Available evidence coming from clinical trials is useful to inform clinical choices but the older people are poorly represented in those trials. Thus evidence supporting the benefit of statin therapy for primary and secondary prevention of fatal and nonfatal ASCVD events in adults aged 75 years and older are limited. The pharmacological therapy of dyslipidemia is recommended by guidelines provided by international expert panels in adults, while in the elderly it is still a matter of debate. Statins are generally well tolerated drugs but their use in the elderly, especially in fragile ones or with multi-pathology that take many other drugs, requires a careful evaluation of the risk-benefit ratio and a shared decision-making process between doctor and patient.

Polyphenol-Rich Black Elderberry Extract Stimulates Transintestinal Cholesterol Excretion

Hypercholesterolemia is the primary risk factor for cardiovascular disease (CVD). Recent studies reported that the stimulation of transintestinal cholesterol excretion (TICE), a nonbiliary cholesterol excretion, can be a strategy for preventing CVD. Black elderberry (Sambucus nigra) has been reported to reduce the risk of CVD via its antioxidant, anti-inflammatory, and hypocholesterolemic effects. However, little is known about the role of black elderberry in intestinal cholesterol metabolism despite its well-known effects on cholesterol homeostasis regulation. To investigate the effects of polyphenol-rich black elderberry extract (BEE) on intestinal cholesterol metabolism, we measured the expression of genes involved in cholesterol biosynthesis and flux in Caco-2 cells. BEE significantly decreased the messenger RNA (mRNA) and protein levels of genes for cholesterol absorption, such as Niemann–Pick C1 Like 1 and ATP-binding cassette transporter A1 (ABCA1). In contrast, there was marked induction of low-density lipoprotein receptor, ABCG5/G8, and ABCB1 in BEE-treated Caco-2 cells. Furthermore, BEE decreased the expression of genes for lipogenesis and altered the mRNA levels of sirtuins. All of the genes altered by BEE were in the direction of flux cholesterol from the basolateral to apical side of enterocytes, indicating stimulation of TICE. These results support the hypocholesterolemic effects of BEE for the prevention of CVD.

Using Elevated Cholesterol Synthesis as a Prognostic Marker in Wilms' Tumor: A Bioinformatic Analysis

Background

Wilms tumor is the most common renal malignancy of children. Identifying factors that could predict the prognosis of patients with Wilms tumor is clinically meaningful. Many studies found tumors with elevated cholesterol synthesis that are featured with dismal prognosis. Even in some clinical trials, people with excessive dietary cholesterol intake and high plasma low-density lipoprotein levels are observed to have increased risk for cancer. However, the role of cholesterol biosynthesis in Wilms tumor has not yet been well clarified.

Methods

RNA sequencing transcriptome data and all corresponding clinicopathological information used in our study were downloaded from the TARGET database. High-throughput sequencing (Fragments Per Kilobase of transcript per Million fragments mapped) data sets of 130 tumor samples and 6 normal samples were obtained for further analysis.

Results

Wilms tumor samples with higher activity of cholesterol synthesis are characterized with worse overall survival (P < 0.05). In addition, Wilms tumor samples with mitigated activity of cholesterol synthesis are featured with better dendritic cell (DC) function and cytolytic activity (P < 0.05). Furthermore, we constructed a prognosis model based on differential expressed cholesterol synthesis-related genes (DECSG), which could predict the OS of patients with Wilms tumor accurately. KEGG and GO analysis of differential expressed genes between tumor samples with high and low cholesterol synthesis indicated that DECSGs are highly enriched in “mitosis nuclear division,” “nuclear division,” “chromosome segregation,” “cell cycle,” “Spliceosome,” and “RNA transport.”

Conclusions

In conclusion, our study reported increased cholesterol synthesis in Wilms tumor predicts a worse prognosis and mitigated cytolytic activity, DC function, and MHC I signature in the tumor microenvironment. We also constructed a prognosis model for predicting the OS of patients with good accuracy, which is promising in clinical translation. Future studies should focus on the detailed mechanism that caused increasing cholesterol which promotes tumor progression and undermines patients' survival.

Benefits of Anthocyanin-Rich Black Rice Fraction and Wood Sterols to Control Plasma and Tissue Lipid Concentrations in Wistar Kyoto Rats Fed an Atherogenic Diet

Background: This study reports on the relative effects of administrating a cyanidin-3-O-glucoside-rich black rice fraction (BRF), a standardized wood sterol mixture (WS), and a combination of both to lower plasma and target tissue lipid concentrations in Wistar Kyoto (WKY) rats fed atherogenic diets. Methods: Male WKY (n = 40) rats were randomly divided into five groups, which included a nonatherogenic control diet and atherogenic diets that included a positive control and atherogenic diets supplemented with BRF or WS, respectively, and a combination of both BRF + WS. Plasma and target tissue liver, heart and aorta cholesterol, and triacylglycerides (TAG) content were also measured. Results: Rats fed atherogenic diets exhibited elevated hyperlipidemia compared to counterparts fed nonatherogenic diets (p < 0.001); this effect was mitigated by supplementing the atherogenic diets with BRF and WS, respectively (p < 0.05). Combining BRF with WS to enrich the supplement lowered cholesterol similar to the WS effect (p < 0.05) and lowered TAG characteristic to the BRF effect (p < 0.05). Conclusions: Rats fed diets containing BRF or WS effectively mitigate the hypercholesterolemia and elevated TAG induced by feeding an atherogenic diet. The benefit of adding BRF + WS together is relevant to the lipid parameter measured and is target tissue-specific.

Age-Related Considerations in Cardio-Oncology

Cardio-Oncology has blossomed as a new field in cardiovascular medicine, in large part due to new therapies, which may have cardiovascular sequelae. Despite this, anthracyclines still serve as cornerstone therapy for most pediatric cancers, several solid tumors and hematological malignancies. Cardiotoxicity is the main limiting concern with anthracyclines, and this is particularly an issue in patients in extremes of age (both young and old patients). Pediatric hearts are susceptible for cardiotoxicity, while in older patients, concomitant risk factors may contribute to lower threshold for cardiotoxic effects. With increasing patient survival, a significant increase in elderly cancer patients and long-term cardiotoxicity effects of anthracyclines, a better mechanistic understanding of age-dependent processes-that define cardiotoxicity-is needed. This review sheds light on how age affects underlying molecular pathways of anthracycline-associated cardiotoxicity and aims to provide preventive strategies that can be used in clinical practice.

Sex differences in body composition, metabolism-related hormones, and energy homeostasis during aging in Wistar rats

Aging affects the body composition and balance of energy metabolism. Here, we collected in a single work several physiological parameters to show how aging and sex differences can influence energy homeostasis. Body mass index (BMI), Lee index, glucose tolerance, glycemia, and lipidogram in fasting were measured in male and female Wistar rats at the ages of 2, 6, 9, 12, and 18 months. We also measured the lipid profile, free fatty acids, glycerol, glycemia, leptin, adiponectin, insulin, corticosterone (CORT), prolactin (PRL), thyroid stimulated hormone, and triiodothyronine (T3) in 3- and 18-month-old rats of both sexes, fed ad libitum. Animals were classified as obese beginning at 2 months in males and 6 months in females. Aged male rats showed hyperglycemia and glucose intolerance compared to young males and old females. In the ad libitum condition, the 18-month males presented higher serum levels of triglycerides, total cholesterol, and free fatty acids than females. The 18-month-old females had higher PRL and CORT concentration than males, but insulin and T3 were higher in 18-month-old males than females. Our work demonstrated that aging processes on energy metabolism in rats is sex specific, with a better lipid profile and glucose tolerance in aged females.

Cholesterol Homeostasis: An In Silico Investigation into How Aging Disrupts Its Key Hepatic Regulatory Mechanisms

The dysregulation of intracellular cholesterol homeostasis is associated with several age-related diseases, most notably cardiovascular disease (CVD). Research in this area has benefitted from using computational modelling to study the inherent complexity associated with the regulation of this system. In addition to facilitating hypothesis exploration, the utility of modelling lies in its ability to represent an array of rate limiting enzymatic reactions, together with multiple feedback loops, which collectively define the dynamics of cholesterol homeostasis. However, to date no model has specifically investigated the effects aging has on this system. This work addresses this shortcoming by explicitly focusing on the impact of aging on hepatic intracellular cholesterol homeostasis. The model was used to investigate the experimental findings that reactive oxygen species induce the total activation of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase (HMGCR). Moreover, the model explored the impact of an age-related decrease in hepatic acetyl-CoA acetyltransferase 2 (ACAT2). The model suggested that an increase in the activity of HMGCR does not have as significant an impact on cholesterol homeostasis as a decrease in hepatic ACAT2 activity. According to the model, a decrease in the activity of hepatic ACAT2 raises free cholesterol (FC) and decreases low-density lipoprotein cholesterol (LDL-C) levels. Increased acetyl CoA synthesis resulted in a reduction in the number of hepatic low-density lipoprotein receptors, and increased LDL-C, FC, and cholesterol esters. The rise in LDL-C was restricted by elevated hepatic FC accumulation. Taken together these findings have important implications for healthspan. This is because emerging clinical data suggest hepatic FC accumulation is relevant to the pathogenesis of non-alcoholic fatty liver disease (NAFLD), which is associated with an increased risk of CVD. These pathophysiological changes could, in part, help to explain the phenomenon of increased mortality associated with low levels of LDL-C which have been observed in certain studies involving the oldest old (≥85 years).

The Debate Over Egg Consumption and Incident Cardiovascular Disease

There is a great debate regarding the association of cholesterol intake from egg consumption and the incidence of cardiovascular disease (CVD). Most studies show that moderate egg consumption is not associated with a significant increase in CVD, stroke, heart failure, and type 2 diabetes mellitus (T2DM), whereas others dispute this fact and state that there is an association with increased egg consumption, especially if they are consumed with saturated fats. In addition, the recent relaxation of cholesterol intake to greater than 300 mg/d by the American College of Cardiology/American Heart Association Nutritional Guidelines has fueled this debate. In order to get a current perspective on the significance of moderate egg consumption with the primary incidence of CVD, a focused Medline search of the English language literature was conducted between 2010 and March 2020 using the terms, cholesterol intake, egg consumption, coronary artery disease, CVD, and T2DM. Nineteen pertinent articles were retrieved, and these, together with collateral literature, will be discussed in this review article. The analysis of data from the articles retrieved indicated that several studies showed that moderate egg consumption (1 egg/d) is not associated with adverse cardiovascular effects in subjects free of CVD or T2DM, whereas other studies showed a positive association, especially in patients with preexisting CVD or T2DM. Therefore, at present, there is no unanimous agreement on this subject, and the controversy will continue until new confirmatory evidence becomes available.

The influence of probiotics on bile acids in diseases and aging

Recent evidence indicates the use of probiotics in the prevention and treatment of diseases. Probiotics are capable of changing the gut microbiota composition and bile acid synthesis to elicit health benefits such as cholesterol-lowering, weight reduction, and improving insulin sensitivity. The aging population is prone to develop diseases because of their decreased physiological and biological systems. Probiotics are one of the promising supplements that may potentially counteract these detrimental effects. This review will discuss the influence of probiotics on bile acids in different populations-the elderly, obese individuals, and those with hypercholesterolemia, type 2 diabetes, hypertension, and non-alcoholic fatty liver disease.

The Impact of Education and Age on Metabolic Disorders

Metabolic disorders, such as obesity, elevated blood pressure, dyslipidemias, insulin resistance, hyperglycemia, and hyperuricemia have all been identified as risk factors for an epidemic of important and widespread chronic-degenerative diseases, such as type 2 diabetes and cardiovascular disease, that constitute some of the world's most important public health challenges. Their increasing prevalence can be associated with an aging population and to lifestyles within an obesogenic environment. Taking educational level as a proxy for lifestyle, and using both logistic and linear regressions, we study the relation between a wide set of metabolic biomarkers, and educational level, body mass index (BMI), age, and sex as correlates, in a population of 1,073 students, academic and non-academic staff at Mexico's largest university (UNAM). Controlling for BMI and sex, we consider educational level and age as complementary measures-degree and duration-of exposure to metabolic insults. Analyzing the role of education across a wide spectrum of educational levels (from primary school to doctoral degree), we show that higher education correlates to significantly better metabolic health when compared to lower levels, and is associated with significantly less risk for waist circumference, systolic blood pressure, glucose, glycosylated hemoglobin, triglycerides, high density lipoprotein and metabolic syndrome (all p < 0.05); but not for diastolic blood pressure, basal insulin, uric acid, low density lipoprotein, and total cholesterol. We classify each biomarker, and corresponding metabolic disorder, by its associated set of statistically significant correlates. Differences among the sets of significant correlates indicate various aetiologies and the need for targeted population-specific interventions. Thus, variables strongly linked to educational level are candidates for lifestyle change interventions. Hence, public policy efforts should be focused on those metabolic biomarkers strongly linked to education, while adopting a different approach for those biomarkers not linked as they may be poor targets for educational campaigns.

Lifetime risk assessment in cholesterol management among hypertensive patients: observational cross-sectional study based on electronic health record data

BACKGROUND

In hypertensive patients, reducing plasma low-density lipoprotein cholesterol level (LDL-C) is one of the main interventions for preventing chronic cardiovascular diseases (CVD). However, LDL-C control remains generally insufficient, also in patients with hypertension. We analyzed Electronic Health Record (EHR) data of 7117 hypertensive patients to find the most potential age and sex subgroups in greatest need for improvement in real life dyslipidemia treatment. Taking into account the current discussion on lifetime CVD risk, we focused on the age dependence in LDL-C control.

METHODS

In this observational cross-sectional study, based on routine electronic health record (EHR) data, we investigated LDL-C control of hypertensive, non-diabetic patients without renal dysfunction or CVD, aged 30 years or more in Finnish primary care setting.

RESULTS

More than half (54% of women and 53% of men) of untreated patients did not meet the LDL-C target of < 3 mmol/l and one third (35% of women and 33% of men) of patients did not reach the target even with the lipid-lowering medication (LLM). Furthermore, higher age was strongly associated with better LDL-C control (p < 0.001) and lower LDL-C level (p < 0.001) in individuals with and without LLM. Higher age was also strongly associated with LLM prescription (p < 0.001). In total, about half of the patients were on LLM (53% of women and 51% of men).

CONCLUSIONS

Our findings indicate that dyslipidemia treatment among Finnish primary care hypertensive patients is generally insufficient, particularly in younger age groups who might benefit the most from CVD risk reduction over time. Clinicians should probably rely more on the lifetime risk of CVD, especially when treating working age hypertensive patients.

The sciences of healthy aging await a theory of health

Debates in fields studying the biological aspects of aging and longevity, such as biogerontology, are often split between 'anti-aging' approaches aimed largely at treating diseases and those focusing more on maintaining, promoting, and even enhancing health. However, it is far from clear what this 'health' is that would be maintained, promoted, or enhanced. Interestingly, what few have yet to fully reflect on is that there is still no theory of health within the health or aging sciences that would provide an integrative explanatory framework akin to other scientific theories. After clarifying why such a theory could be useful, I discuss five general features of medical theories that could be used to evaluate the utility of a given proposal. With these features in hand, I suggest that philosophers and scientists work together on analyzing actual medical research (experimental analysis), and the ways in which a theoretical construct of 'health' is being progressively identified and measured therein. I conclude by suggesting that research fields studying stress and aging might be particularly helpful in developing candidates for theory construction due to their broad scope, increasing specificity, and potential for providing integrative explanations.