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

Integrative metagenomics and metabolomics reveal age-associated gut microbiota and metabolite alterations in a hamster model of COVID-19

Aging is a key contributor of morbidity and mortality during acute viral pneumonia. The potential role of age-associated dysbiosis on disease outcomes is still elusive. In the current study, we used high-resolution shotgun metagenomics and targeted metabolomics to characterize SARS-CoV-2-associated changes in the gut microbiota from young (2-month-old) and aged (22-month-old) hamsters, a valuable model of COVID-19. We show that age-related dysfunctions in the gut microbiota are linked to disease severity and long-term sequelae in older hamsters. Our data also reveal age-specific changes in the composition and metabolic activity of the gut microbiota during both the acute phase (day 7 post-infection, D7) and the recovery phase (D22) of infection. Aged hamsters exhibited the most notable shifts in gut microbiota composition and plasma metabolic profiles. Through an integrative analysis of metagenomics, metabolomics, and clinical data, we identified significant associations between bacterial taxa, metabolites and disease markers in the aged group. On D7 (high viral load and lung epithelial damage) and D22 (body weight loss and fibrosis), numerous amino acids, amino acid-related molecules, and indole derivatives were found to correlate with disease markers. In particular, a persistent decrease in phenylalanine, tryptophan, glutamic acid, and indoleacetic acid in aged animals positively correlated with poor recovery of body weight and/or lung fibrosis by D22. In younger hamsters, several bacterial taxa (Eubacterium, Oscillospiraceae, Lawsonibacter) and plasma metabolites (carnosine and cis-aconitic acid) were associated with mild disease outcomes. These findings support the need for age-specific microbiome-targeting strategies to more effectively manage acute viral pneumonia and long-term disease outcomes.

Probiotics for the treatment of hyperlipidemia: Focus on gut-liver axis and lipid metabolism

Hyperlipidemia, a metabolic disorder marked by dysregulated lipid metabolism, is a key contributor to the onset and progression of various chronic diseases. Maintaining normal lipid metabolism is critical for health, as disruptions lead to dyslipidemia. The gut and liver play central roles in lipid homeostasis, with their bidirectional communication, known as the gut-liver axis, modulated by bile acids (BAs), gut microbiota, and their metabolites. BAs are essential for regulating their own synthesis, lipid metabolism, and anti-inflammatory responses, primarily through the farnesoid X receptor (FXR) and Takeda G protein-coupled receptor 5 (TGR5). Available evidence suggests that high-fat diet-induced the gut microbiota dysbiosis can induce "leaky gut," allowing toxic microbial metabolites to enter the liver via portal circulation, triggering liver inflammation and lipid metabolism disturbances, ultimately leading to hyperlipidemia. Extensive studies have highlighted the roles of probiotics and Traditional Chinese Medicine (TCM) in restoring gut-liver axis balance and modulating lipid metabolism through regulating the levels of lipopolysaccharides, short-chain fatty acids, and BAs. However, the therapeutic potential of probiotics and TCM for hyperlipidemia remains unclear. Here, firstly, we explore the intricate interplay among gut microbiota and metabolites, lipid metabolism, gut-liver axis, and hyperlipidemia. Secondly, we summarize the mechanisms by which probiotics and TCM can alleviate hyperlipidemia by altering the composition of gut microbiota and regulating lipid metabolism via the gut-liver axis. Finally, we emphasize that more clinical trials of probiotics and TCM are necessary to examine their effects on lipid metabolism and hyperlipidemia.

Potential Causal Relationship Between Extensive Lipid Profiles and Various Hair Loss Diseases: Evidence From Univariable and Multivariable Mendelian Randomization Analyses

BACKGROUND

Hair loss disorders, including non-cicatricial forms such as alopecia areata (AA) and androgenetic alopecia (AGA), as well as cicatricial forms, represent significant dermatological concerns influenced by various factors, including lipid metabolism. While observational studies and clinical trials have suggested a link between lipid levels and hair loss, the causal relationship remains unclear.

METHODS

We conducted a comprehensive analysis of 983 lipid variables [including triglycerides (TG), fatty acids, cholesterol, cholesterol esters, phospholipids, and lipoproteins] and 4 hair loss disorders. Two-sample univariable Mendelian randomization (UVMR) and multivariable Mendelian randomization (MVMR) analyses were employed to investigate the causal effects of lipids on hair loss disorders. Sensitivity analyses were performed to ensure the robustness of our findings.

RESULTS

The UVMR analysis identified 56 significant causal associations between lipid levels and hair loss disorders, with cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), TG, apolipoprotein A1, apolipoprotein B, and lipoprotein(a) emerging as key contributors. The MVMR analysis evaluated the independent effects of HDL-C, LDL-C, and TG on alopecia disorders, identifying significant associations only between HDL-C, TG, and AA. Sensitivity analyses confirmed the consistency and robustness of these results.

CONCLUSION

This study provides strong evidence for potential causal associations between lipids and hair loss disorders, highlighting potential therapeutic targets and the importance of lipid management in affected patients.

Global trend and disparity in the burden of thyroid cancer attributable to high body-mass index from 1990 to 2021 and projection to 2049: a systematic analysis based on the Global Burden of Disease Study 2021

BACKGROUND

Obesity and overweight are increasingly recognized as significant risk factors for the incidence and progression of thyroid cancer (TC). However, its epidemiological investigation including the disease burden and its trends remains insufficiently explored. This research aimed to reveal and predict the disease burden of thyroid cancer attributable to high body-mass index (TC-HBMI), which would offer significant references for focused prevention and disease management methods.

METHODS

The study extracted data from the Global Burden of Disease Study 2021 (GBD 2021). Deaths case, disability-adjusted life years (DALYs) case, age-standardized mortality rate (ASMR) and age-standardized DALYs rate (ASDR) were obtained from GBD 2021 to assess the global burden from 1990 to 2021. Decomposition analysis explored the driving factors to TC-HBMI. The Average Annual Percent Change (AAPC) in ASMR and ASDR of TC-HBMI was determined to analyze temporal trends by Joinpoint regression analysis. Bayesian age-period-cohort (BAPC) model was utilized to project the disease burden untill 2049.

RESULTS

The global deaths and DALYs of TC-HBMI were 5,255 and 144,955 in 2021, exhibiting a continuous growth trend over the past 32 years. The ASMR and ASDR for males showed faster growth. The disease burden was greatest among middle-aged and older populations, while the rapidly increase in adolescents should not be overlooked. High socio-demographic index (SDI) regions and Latin America each recorded the highest disease burden within their respective categories of SDI regions and GBD regions. Additionally, Predictive models indicated a gradual upward trend from 2022 to 2049.

CONCLUSION

The study revealed that the global disease burden of TC-HBMI had continuously increased from 1990 to 2021, and it was predicted to escalate until 2049. The findings emphasize the need for more detailed TC screening and weight loss measures tailored to specific regions and populations, which would benefit efforts to curb the projected rise in TC-HBMI deaths and DALYs.

Association of Year-to-Year Lipid Variability With Risk of Cognitive Decline and Dementia in Community-Dwelling Older Adults

BACKGROUND AND OBJECTIVES

Lipid metabolism in older adults is affected by various factors including biological aging, functional decline, reduced physiologic reserve, and nutrient intake. The dysregulation of lipid metabolism could adversely affect brain health. This study investigated the association between year-to-year intraindividual lipid variability and subsequent risk of cognitive decline and dementia in community-dwelling older adults.

METHODS

ASPirin in Reducing Events in the Elderly (ASPREE) was a randomized trial of aspirin, involving 19,114 participants aged 65 years and older from Australia and the United States who were free of dementia and major cognitive impairment. ASPREE-eXTension is the post-trial observational follow-up of participants, currently to a maximum of 11 years. This post hoc analysis included participants who had lipid levels measured at baseline and in years 1, 2, and 3. Year-to-year variability in total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c), and triglycerides over the first 3 years was quantified using variability independent of the mean. Individuals who initiated or discontinued lipid-lowering therapy during this period were excluded. Multivariable Cox proportional hazards regression was used to analyze associations with incident dementia, adjudicated by expert panels, and cognitive impairment with no dementia (CIND) confirmed by a battery of cognitive tests, occurring after year 3. A linear mixed model was used for assessing the association with changes in 4 cognitive function domains, including global, memory, processing speed, verbal fluency, and a composite score from baseline to the end of follow-up.

RESULTS

The analysis included 9,846 individuals (median [interquartile range] age: 73.9 [71.7-77.3] years, 54.9% female). 509 incident dementia and 1,760 CIND events were recorded over a median follow-up of 5.8 and 5.4 years after variability assessment. The hazard ratios (95% CI) comparing the highest and lowest quartiles of TC and LDL-c variability were 1.60 (1.23-2.08) and 1.48 (1.15-1.91) for dementia and 1.23 (1.08-1.41) and 1.27 (1.11-1.46) for CIND. Higher TC and LDL-c variability was also associated with a faster decline in global cognition, episodic memory, psychomotor speed, and the composite score (all p < 0.001). No strong evidence was found for an association of HDL-c and triglyceride variability with dementia and cognitive change.

DISCUSSION

Tracking variability of TC and LDL-c may serve as a novel biomarker of incident dementia and cognitive decline in older adults.

Association of biochemical indicators with multimorbidity in 19,624 older adult individuals with chronic diseases: a study from Jindong District, Jinhua City, China

Background

Chronic disease multimorbidity is influenced by multiple factors, but with little knowledge on the impact of biochemical indicators. This study aims to investigate the prevalence of multimorbidity of chronic diseases among older adult individuals in the community, as well as the factors related to biochemical indicators associated with chronic disease multimorbidity.

Methods

The study included 19,624 older adult individuals aged 60 and above in Jindong District, Jinhua City, Zhejiang Province, China. Participants completed a national standardized older adult health examination in the community. Chi-square tests and logistic regression were employed to evaluate the potential factors of biochemical indicators related to multimorbidity of chronic diseases.

Results

The multimorbidity rate of chronic diseases in older adult patients is 70.3%. Each chronic disease coexists with one or more other chronic diseases in over 75% of cases. Among the biochemical indicators, hemoglobin (Hb) (OR = 1.46, 95%CI: 1.13-1.90), white blood cell count (WBC) (OR = 1.25, 95%CI: 1.02-1.54), red blood cell count (RBC) (OR = 1.36, 95%CI: 1.10-1.69), urinary protein (U-PRO) (OR = 1.10, 95%CI: 1.02-1.19), urinary glucose (U-GLU) (OR = 1.44, 95%CI: 1.23-1.67), alanine aminotransferase (ALT) (OR = 1.71, 95%CI: 1.39-2.10), aspartate aminotransferase (AST) (OR = 1.22, 95%CI: 1.05-1.41), creatinine (Cr) (OR = 1.28, 95%CI: 1.16-1.42), uric acid (UA) (OR = 1.36, 95%CI: 1.22-1.51), total cholesterol (TC) (OR = 1.76, 95%CI: 1.59-1.95), triglycerides (TG) (OR = 2.63, 95%CI: 2.46-2.82), low-density lipoprotein cholesterol (LDL-C) (OR = 1.84, 95%CI: 1.60-2.11), high-density lipoprotein cholesterol (HDL-C) (OR = 10.99, 95%CI: 8.12-14.90), and fasting blood glucose (FBG) (OR = 1.89, 95%CI: 1.74-2.05) are associated with the risk of multimorbidity of chronic diseases (p < 0.05). Among these, lipid parameters demonstrated the strongest associations with multimorbidity risk, with low HDL-C showing an 11-fold increase and elevated TG a 2.63-fold increase.

Conclusion

This study found that the prevalence of multimorbidity among older adult individuals in this region reached 70.3%. Multiple biochemical indicators were significantly associated with multimorbidity, particularly lipid parameters (low HDL-C and elevated TG), glucose parameters (elevated FBG and positive U-GLU), liver function (elevated ALT), and hemoglobin levels. These findings provide important evidence for research on factors associated with multimorbidity in the older adult population.

Bisphenol S Induces Lipid Metabolism Disorders in HepG2 and SK-Hep-1 Cells via Oxidative Stress

Bisphenol S (BPS) is a typical endocrine disruptor associated with obesity. To observe BPS effects on lipid metabolism in HepG2 and SK-Hep-1 human HCC cells, a CCK-8 assay was used to assess cell proliferation in response to BPS, and the optimal concentration of BPS was selected. Biochemical indices such as triglyceride (TG) and total cholesterol (T-CHO), and oxidative stress indices such as malondialdehyde (MDA) and catalase (CAT) were measured. ROS and MDA levels were significantly increased after BPS treatment for 24 h and 48 h (p < 0.05), indicating an oxidative stress response. Alanine aminotransferase (ALT), T-CHO, and low-density lipoprotein cholesterol (LDL-C) levels also increased significantly after 24 or 48 h BPS treatments (p < 0.05). RT-PCR and Western blot analyses detected mRNA or protein expression levels of peroxisome proliferator-activated receptor α (PPARα) and sterol regulatory element-binding protein 1c (SREBP1C). The results indicated that BPS could inhibit the mRNA expression of PPARα and carnitine palmitoyl transferase 1B (CPT1B), reduce lipid metabolism, promote mRNA or protein expression of SREBP1C and fatty acid synthase (FASN), and increase lipid synthesis. Increased lipid droplets were observed using morphological Oil Red O staining. Our study demonstrates that BPS may cause lipid accumulation by increasing oxidative stress and perturbing cellular lipid metabolism.

Effects of age and diet on triglyceride metabolism in mice

Both age and diet can contribute to alterations in triglyceride metabolism and subsequent metabolic disease. In humans, plasma triglyceride levels increase with age. Diets high in saturated fats can increase triglyceride levels while diets high in omega-3 fatty acids decrease triglyceride levels. Here we asked how age and long-term diet altered triglyceride metabolism in mice. We fed male and female C57Bl/6 mice a low-fat diet, a western diet (WD), or a diet high in polyunsaturated and omega-3 fatty acids (n3D) for up to 2 years. We measured survival, body composition, plasma triglyceride levels, chylomicron clearance, and oral fat, glucose, and insulin tolerance. Triglyceride levels in mice did not increase with age, regardless of diet. Oral fat tolerance increased with age, while chylomicron clearance remained unchanged. Decreased survival was observed in WD-fed mice. Interestingly, n3D-fed mice gained more lean mass and had lower insulin levels than WD-fed or LFD-fed mice. Moreover, triglyceride uptake into the hearts of n3D-fed mice was strikingly higher than in other groups. Our data indicate that in C57Bl/6 mice, age-induced changes in triglyceride metabolism differ from those observed in humans. Mice, like humans, appeared to have decreased fat absorption with age, but in mice plasma triglyceride clearance did not decrease with age, resulting in lower plasma triglyceride levels and improved fat tolerance with age. Although a chronic diet high in omega-3 fatty acids increased insulin sensitivity and triglyceride uptake specifically into the heart, how these observations are connected is unclear.

Caffeine-Induced Upregulation of pas-1 and pas-3 Enhances Intestinal Integrity by Reducing Vitellogenin in Aged Caenorhabditis elegans Model

Background: Intestinal aging is characterized by declining protein homeostasis via reduced proteasome activity, which are hallmarks of age-related diseases. Our previous study showed that caffeine intake improved intestinal integrity with age by reducing vitellogenin (VIT, yolk protein) in C. elegans. In this study, we investigated the regulatory mechanisms by which caffeine intake improves intestinal integrity and reduces vitellogenin (VIT) production in aged Caenorhabditis elegans. Methods: We performed RNA-seq analysis, and qRT-PCR to validate and confirm the RNA-seq results. Transgenic worms with VIT-2::GFP and VIT-6::GFP were used for measuring VIT production. dsRNAi was conducted to elucidate the roles of pas-1 and pas-3 genes. Results:pas-1 and pas-3, a C. elegans ortholog of human PASM4, was upregulated by caffeine intake. They reduced VIT production by repressing unc-62, a transcriptional activator of vit expression. Interestingly, vit-2 was required for pas-1 and pas-3 expression, and RNAi of pas-1 and pas-3 promoted intestinal atrophy and colonization, suggesting a balancing mechanism for VIT levels in intestinal health. Additionally, lifespan was extended by caffeine intake (2 ± 0.05 days), however, this effect was not observed by pas-1 but not pas-3 RNAi, suggesting that the mode of action for an anti-aging effect of caffeine through pas-1 and pas-3 is distinctive. The lifespan extended by pas-1 was mediated by SKN-1 activation. Conclusions: Caffeine intake enhances intestinal health through proteasome activity and extends lifespan in aged C. elegans by upregulating pas-1 and pas-3. These findings suggest that caffeine consumption mitigates age-related proteasome impairment and maintains intestinal integrity during aging.

Marine Fungi Bioactives with Anti-Inflammatory, Antithrombotic and Antioxidant Health-Promoting Properties Against Inflammation-Related Chronic Diseases

Fungi play a fundamental role in the marine environment, being promising producers of bioactive molecules in the pharmacological and industrial fields, which have demonstrated potential health benefits against cardiovascular and other chronic diseases. This review pertains to the analysis of the lipid compositions across various species of marine fungi and their constantly discovered substances, as well as their anti-inflammatory, antioxidant, and antithrombotic effects. The health-promoting aspects of these microorganisms will be explored, through the investigation of several mechanisms of action and interference of their bioactives in biochemical pathways. Despite exceptional results in this field, the potential of marine microorganisms remains largely unexplored due to the limited number of specialists in marine microbiology and mycology, a relatively recent science with significant contributions and potential in biodiversity and biotechnology.

Regulating Lipid Metabolism in Gout: A New Perspective with Therapeutic Potential

Gout is a metabolic disease characterized by inflammatory arthritis caused by abnormal uric acid metabolism. It is often complicated with cardio-renal damage and vascular lesions. In recent years, the relationship between lipid metabolism and gout has attracted increasing attention. Changes in blood lipids in gout patients are often clinically detectable and closely related to uric acid metabolism and inflammatory response in gout. With the development of lipidomics, the changes in small lipid molecules and their metabolic pathways have been gradually discovered, yielding a greater understanding of the lipid metabolism changes in gout patients and their potential role in gout development. Through searching the literature on lipid metabolism in gout since 2000 in PubMed and Web of Science, this article reviewed lipid metabolism changes in gout patients and their role in the risk of gout, uric acid metabolism, inflammatory response, and comorbidities. Additionally, the strategies to regulate the abnormal lipid metabolism in gout have also been summarized from the aspects of drugs, diet, and exercise. These will provide a new perspective for understanding gout pathogenesis and its treatment and management.

Combined Effects of Environmental Metals and Physiological Stress on Lipid Dysregulation

BACKGROUND

Cardiovascular diseases (CVD) are a leading cause of mortality worldwide, influenced by genetic, environmental, and behavioral factors. This study examines the relationship between heavy metal exposure, chronic physiological stress (allostatic load), and lipid profiles, which are markers of CVD risk, using data from the National Health and Nutrition Examination Survey (NHANES) 2017-2018.

METHODS

We utilized structural equation modeling (SEM) to explore the associations between blood levels of lead, cadmium, allostatic load (AL), and lipid measures (low-density lipoprotein (LDL), high-density lipoprotein (HDL), and triglycerides). The AL index was derived from cardiovascular, inflammatory, and metabolic biomarkers and categorized into quartiles to identify high-risk individuals, with an index out of 10 subsequently developed.

RESULTS

The SEM analysis revealed that both heavy metal exposure and allostatic load are significantly associated with lipid profiles. Higher levels of lead and cadmium were associated with increased LDL and triglycerides, while higher AL scores were linked to increased LDL and triglycerides and decreased HDL levels. Age was also a significant factor, showing positive correlations with LDL and triglycerides, and a negative correlation with HDL.

CONCLUSIONS

This study underscores the multifactorial nature of CVD, highlighting the combined impact of environmental pollutants and physiological stress on lipid dysregulation. These findings suggest the need for integrated public health strategies that address both environmental exposures and chronic stress to mitigate cardiovascular risk. Further research is warranted to explore the underlying mechanisms and develop targeted interventions.

Predictive value of early postoperative blood lipid metabolism for anastomotic leakage after esophageal cancer surgery

OBJECTIVE

To explore the clinical value of assessing early postoperative blood lipid metabolism levels in predicting anastomotic leakage (AL) after esophageal cancer (EC) surgery.

METHODS

The clinical data of EC patients who underwent surgery at the Northern Jiangsu People's Hospital from May 2021 to May 2023 were retrospectively studied. Totally, 28 patients who developed AL were included in the AL group, while 110 patients who did not develop AL were included in the non-AL group. Outcomes compared between the two groups included clinical baseline data, total cholesterol (TC), triglycerides, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) levels. Logistic regression analysis was performed to identify independent risk factors for postoperative AL. The predictive value of early postoperative blood lipid metabolism levels for AL was evaluated using Receiver Operating Characteristic (ROC) curves.

RESULTS

The AL group exhibited significantly elevated levels of TC and LDL-C but significantly reduced HDL-C levels compared to the non-AL group (all P<0.05). However, there was no significant difference in triglyceride levels between the two groups (P>0.05). Logistic regression analysis revealed that low BMI (P=0.012; OR: 4.409; 95% CI: 1.391-13.976), comorbid hypertension (P=0.011; OR: 5.891; 95% CI: 1.492-23.259), comorbid diabetes (P=0.022; OR: 4.522; 95% CI: 1.238-16.521), low HDL-C (P=0.007; OR: 19.965; 95% CI: 2.293-173.809), and high LDL-C (P=0.012; OR: 4.321; 95% CI: 1.388-13.449) were independent risk factors for developing AL after EC surgery. The combined prediction model using TC, HDL-C, and LDL-C yielded an area under the curve (AUC) of 0.876, with a sensitivity of 79.09%, specificity of 85.71%, and overall accuracy of 80.44%, significantly outperforming individual lipid measurements.

CONCLUSION

The combined assessment of TC, HDL-C, and LDL-C can effectively predict the occurrence of AL after EC surgery. For EC patients with relatively low BMI, hypertension, diabetes, relatively low HDL-C, and relatively high LDL-C, prioritizing weight management, hypertension and diabetes control, and lipid management can significantly reduce the risk of AL post-surgery.

Resveratrol suppresses hepatic fatty acid synthesis and increases fatty acid β-oxidation via the microRNA-33/SIRT6 signaling pathway

Hyperlipidemia is a strong risk factor for numerous diseases. Resveratrol (Res) is a non-flavonoid polyphenol organic compound with multiple biological functions. However, the specific molecular mechanism and its role in hepatic lipid metabolism remain unclear. Therefore, the aim of the present study was to elucidate the mechanism underlying how Res improves hepatic lipid metabolism by decreasing microRNA-33 (miR-33) levels. First, blood miR-33 expression in participants with hyperlipidemia was detected by reverse transcription-quantitative PCR, and the results revealed significant upregulation of miR-33 expression in hyperlipidemia. Additionally, after transfection of HepG2 cells with miR-33 mimics or inhibitor, western blot analysis indicated downregulation and upregulation, respectively, of the mRNA and protein expression levels of sirtuin 6 (SIRT6). Luciferase reporter analysis provided further evidence for binding of miR-33 with the SIRT6 3'-untranslated region. Furthermore, the levels of peroxisome proliferator-activated receptor-γ (PPARγ), PPARγ-coactivator 1α and carnitine palmitoyl transferase 1 were increased, while the concentration levels of acetyl-CoA carboxylase, fatty acid synthase and sterol regulatory element-binding protein 1 were decreased when SIRT6 was overexpressed. Notably, Res improved the basic metabolic parameters of mice fed a high-fat diet by regulating the miR-33/SIRT6 signaling pathway. Thus, it was demonstrated that the dysregulation of miR-33 could lead to lipid metabolism disorders, while Res improved lipid metabolism by regulating the expression of miR-33 and its target gene, SIRT6. Thus, Res can be used to prevent or treat hyperlipidemia and associated diseases clinically by suppressing hepatic fatty acid synthesis and increasing fatty acid β-oxidation.

Effects of Age and Diet on Triglyceride Metabolism in Mice

Background

Both age and diet can contribute to alterations in triglyceride metabolism and subsequent metabolic disease. In humans, plasma triglyceride levels increase with age. Diets high in saturated fats can increase triglyceride levels while diets high in omega-3 fatty acids decrease triglyceride levels. Here we asked how age and long-term diet effected triglyceride metabolism in mice.

Methods

We fed male and female mice a low-fat diet, a western diet, or a diet high in polyunsaturated and omega-3 (n-3) fatty acids for up to 2 years. We measured survival, body composition, plasma triglyceride levels, chylomicron clearance, and oral fat, glucose, and insulin tolerance.

Results

Triglyceride levels in mice did not increase with age, regardless of diet. Oral fat tolerance increased with age, while chylomicron clearance remained unchanged. Mice fed western diet had decreased survival. Interestingly, mice fed the n-3 diet gained more lean mass, and had lower insulin levels than mice fed either low-fat or western diet. Moreover, triglyceride uptake into the hearts of mice fed the n-3 diet was strikingly higher than in other groups.

Conclusions

In mice, age-induced changes in triglyceride metabolism did not match those in humans. Our data suggested that mice, like humans, had decreased fat absorption with age, but plasma triglyceride clearance did not decrease with age in mice, resulting in lower plasma triglyceride levels and improved oral fat tolerance with age. A chronic diet high in n-3 fatty acids increased insulin sensitivity and uptake of triglycerides specifically into the heart but how these observations are connected is unclear.

Bazi Bushen ameliorates age-related energy metabolism dysregulation by targeting the IL-17/TNF inflammatory pathway associated with SASP

BACKGROUND

Chronic inflammation and metabolic dysfunction are key features of systemic aging, closely associated with the development and progression of age-related metabolic diseases. Bazi Bushen (BZBS), a traditional Chinese medicine used to alleviate frailty, delays biological aging by modulating DNA methylation levels. However, the precise mechanism of its anti-aging effect remains unclear. In this study, we developed the Energy Expenditure Aging Index (EEAI) to estimate biological age. By integrating the EEAI with transcriptome analysis, we aimed to explore the impact of BZBS on age-related metabolic dysregulation and inflammation in naturally aging mice.

METHODS

We conducted indirect calorimetry analysis on five groups of mice with different ages and utilized the data to construct EEAI. 12 -month-old C57BL/6 J mice were treated with BZBS or β-Nicotinamide Mononucleotide (NMN) for 8 months. Micro-CT, Oil Red O staining, indirect calorimetry, RNA sequencing, bioinformatics analysis, and qRT-PCR were performed to investigate the regulatory effects of BZBS on energy metabolism, glycolipid metabolism, and inflammaging.

RESULTS

The results revealed that BZBS treatment effectively reversed the age-related decline in energy expenditure and enhanced overall metabolism, as indicated by the aging index of energy expenditure derived from energy metabolism parameters across various ages. Subsequent investigations showed that BZBS reduced age-induced visceral fat accumulation and hepatic lipid droplet aggregation. Transcriptomic analysis of perirenal fat and liver indicated that BZBS effectively enhanced lipid metabolism pathways, such as the PPAR signaling pathway, fatty acid oxidation, and cholesterol metabolism, and improved glycolysis and mitochondrial respiration. Additionally, there was a significant improvement in inhibiting the inflammation-related arachidonic acid-linoleic acid metabolism pathway and restraining the IL-17 and TNF inflammatory pathways activated via senescence associated secretory phenotype (SASP).

CONCLUSIONS

BZBS has the potential to alleviate inflammation in metabolic organs of naturally aged mice and maintain metabolic homeostasis. This study presents novel clinical therapeutic approaches for the prevention and treatment of age-related metabolic diseases.

Inflammaging and fatty acid oxidation in monocytes and macrophages

Fatty acid oxidation (FAO), primarily known as β-oxidation, plays a crucial role in breaking down fatty acids within mitochondria and peroxisomes to produce cellular energy and preventing metabolic dysfunction. Myeloid cells, including macrophages, microglia, and monocytes, rely on FAO to perform essential cellular functions and uphold tissue homeostasis. As individuals age, these cells show signs of inflammaging, a condition that includes a chronic onset of low-grade inflammation and a decline in metabolic function. These lead to changes in fatty acid metabolism and a decline in FAO pathways. Recent studies have shed light on metabolic shifts occurring in macrophages and monocytes during aging, correlating with an altered tissue environment and the onset of inflammaging. This review aims to provide insights into the connection of inflammatory pathways and altered FAO in macrophages and monocytes from older organisms. We describe a model in which there is an extended activation of receptor for advanced glycation end products, nuclear factor-κB (NF-κB) and the nod-like receptor family pyrin domain containing 3 inflammasome within macrophages and monocytes. This leads to an increased level of glycolysis, and also promotes pro-inflammatory cytokine production and signaling. As a result, FAO-related enzymes such as 5' AMP-activated protein kinase and peroxisome proliferator-activated receptor-α are reduced, adding to the escalation of inflammation, accumulation of lipids, and heightened cellular stress. We examine the existing body of literature focused on changes in FAO signaling within macrophages and monocytes and their contribution to the process of inflammaging.

New Insights into High-Fat Diet with Chronic Diseases

Chronic diseases, encompassing conditions such as heart disease, cancer, and diabetes, represent a significant global health challenge and are the leading causes of mortality worldwide [...].