Lipoprotein Lipase Research Articles

The obesogenic effects of Bisphenol A and its analogues are differentially regulated via PPARγ transactivation in mouse 3T3-L1 cells.

Exposure to environmental pollutants with obesogenic activity is being recognised as one of the contributing factors to the obesity epidemic. Bisphenol A (BPA) has been shown to stimulate adipogenesis in both human and mouse preadipocytes, to increase body weight and affect lipid metabolism in animal and epidemiological studies. Regulatory action and public concern has prompted industry to replace BPA with other structurally similar analogues that may have similar effects. In this study we investigated the effects of fifteen BPA analogues on adipogenesis in the mouse 3T3-L1 pre-adipocyte cell model in order to determine their adipogenic activity relative to BPA. 3T3-L1 cells were treated with increasing concentrations of BPA and replacements and mRNA expression of the mature adipocyte markers fatty acid binding protein 4 (Fabp4), perilipin (Plin) lipoprotein lipase (Lpl)and peroxisome proliferator-activated receptor (Ppar)γ and lipid accumulation were assessed. In addition, a luciferase reporter assay for PPARγ transactivation was employed to investigate mechanism of action. Our results show that BPC, BPS-MAE, BPS-MPE and TGSA, were the most adipogenic bisphenols, as shown by a robust increase in lipid accumulation and mRNA expression of adipogenic markers. BPS-MPE, BPC, BTUM, TGSA and D8 increased PPARγ transcriptional activity. Despite its ability to activate PPARγ in the transcriptional assay D8 did not affect adipogenesis in this cell model.

What is the phenotype of heterozygous lipoprotein lipase deficiency?

Purpose of review Genetic testing of patients with severe hypertriglyceridemia often identifies a single heterozygous pathogenic variant in the LPL gene. The complex and variable phenotype associated with this genotype is the topic of this review. Recent findings Previous research showed that heterozygosity for lipoprotein lipase deficiency is associated with reduced but variable post heparin lipolytic activity alongside inconsistent plasma lipid phenotypes ranging from normal to mild-to-moderate to severe hypertriglyceridemia. Recent research confirms and extends these observations, showing that a heterozygous individual can express a highly variable phenotype over time, depending on the presence of secondary factors. About 10% (range 8–20%) of patients with severe hypertriglyceridemia or multifactorial chylomicronemia syndrome are heterozygous for a rare pathogenic LPL variant, and a clinically relevant minority of these has recalcitrant or sustained hypertriglyceridemia. Summary Heterozygosity for lipoprotein lipase deficiency predisposes to hypertriglyceridemia, which is sometimes severe depending on secondary factors, but is typically quite responsive to routine interventions such as diet, lifestyle and existing lipid-lowering therapies. However, many heterozygotes for pathogenic variants in LPL have completely normal plasma lipids.

Lipoprotein Lipase: Structure, Function, and Genetic Variation.

Biallelic rare pathogenic loss-of-function (LOF) variants in lipoprotein lipase (LPL) cause familial chylomicronemia syndrome (FCS). Heterozygosity for these same variants is associated with a highly variable plasma triglyceride (TG) phenotype ranging from normal to severe hypertriglyceridemia (HTG), with longitudinal variation in phenotype severity seen often in a given carrier. Here, we provide an updated overview of genetic variation in LPL in the context of HTG, with a focus on disease-causing and/or disease-associated variants. We provide a curated list of 300 disease-causing variants discovered in LPL, as well as an exon-by-exon breakdown of the LPL gene and protein, highlighting the impact of variants and the various functional residues of domains of the LPL protein. We also provide a curated list of variants of unknown or uncertain significance, many of which may be upgraded to pathogenic/likely pathogenic classification should an additional case and/or segregation data be reported. Finally, we also review the association between benign/likely benign variants in LPL, many of which are common polymorphisms, and the TG phenotype.

Competitive displacement of lipoprotein lipase from heparan sulfate is orchestrated by a disordered acidic cluster in GPIHBP1.

Movement of lipoprotein lipase (LPL) from myocytes or adipocytes to the capillary lumen is essential for intravascular lipolysis and plasma triglyceride homeostasis-low LPL activity in the capillary lumen causes hypertriglyceridemia. The trans-endothelial transport of LPL depends on ionic interactions with GPIHBP1's intrinsically disordered N-terminal tail, which harbors two acidic clusters at positions 5-12 and 19-30. This polyanionic tail provides a molecular switch that controls LPL detachment from heparan sulfate proteoglycans (HSPGs) by competitive displacement. When the acidic tail was neutralized in gene-edited mice, LPL remained trapped in the sub-endothelial spaces triggering hypertriglyceridemia. Due to its disordered state, the crystal structure of LPL•GPIHBP1 provided no information on these electrostatic interactions between LPL and GPIHBP1s acidic tail. In the current study, we positioned the acidic tail on LPL using zero-length crosslinking. Acidic residues at positions 19-30 in GPIHBP1 mapped to Lys445, Lys441, Lys414 and Lys407 close to the interface between the C- and N-terminal domains in LPL. Modeling this interface revealed widespread polyelectrolyte interactions spanning both LPL domains, which explains why the acidic tail stabilizes LPL activity and protein conformation. In functional assays, we showed that the acidic cluster at 19-30 also had the greatest impact on preserving LPL activity, mitigating ANGPTL4-catalyzed LPL inactivation, preventing PSCK3-mediated LPL cleavage, and, importantly, displacing LPL from HSPGs. Our current study provides key insights into the biophysical mechanism(s) orchestrating intravascular compartmentalization of LPL activity-an intriguing pathway entailing competitive displacement of HSPG-bound LPL by a disordered acidic tail in GPIHBP1.

Relationship between serum levels of ANGPTL8, Apo C2, and human placental lactogen (hPL) in patients with gestational diabetes mellitus: Interaction of LPL regulators with hPL, a possible contributing factor to insulin resistance.

Gestational diabetes mellitus (GDM) is defined as glucose intolerance during pregnancy. We aimed to investigate the potential effects of betatrophin and ApoC2 in GDM, focusing on their roles in LPL (lipoprotein lipase) regulation and their relationship with hPL to elucidate the possible impact of hPL on lipid metabolism and its potential contribution to the development of GDM. Thirty pregnant women with normal glucose tolerance and 29 with gestational diabetes mellitus (diagnosed by 75g OGTT between 24 and 28 weeks) were included in the study. Serum betatrophin, hPL, and ApoC2 were measured by Elisa and HOMA-IR was calculated. In the GDM group, hPL levels correlated with betatrophin and ApoC2 (r=0.552, p<0.05; r=0.588, p<0.05 respectively) while betatrophin correlated with the ApoC2 (r=0.584, p<0.05). A linear relationship between hPL and betatropin and also between hPL and ApoC2 values in the control group (r=0.454, p<0.05; r=0.779, p<0.01 respectively) were observed. ApoC2 levels in the GDM group (n=20) with HOMA-IR cut-off >2.5 were significantly higher than the control group (n=10) (p<0.05). There was also a positive relationship between betatrophin and ApoC2 (r=0.591) (p<0.05). GDM patients may have impaired LPL enzyme regulation in addition to insulin resistance, with hPL potentially contributing to this disruption. Impaired lipoprotein lipase activity and its dysregulation secondary to genetic disorders may play a role in the etiopathogenesis of GDM. Further investigation into the correlation between betatrophin, ApoC2, and other LPL modulators in patients with various forms of diabetes could be beneficial for understanding this interaction more comprehensively.

Olanzapine exposure disordered lipid metabolism, gut microbiota and behavior in zebrafish (Danio rerio).

Olanzapine (OLZ) is widely used in the treatment of schizophrenia, and its metabolic side effects have garnered significant attention in recent years. Despite this, the specific side effects of OLZ and the underlying mechanisms remain inadequately understood. To address this gap, zebrafish (Danio rerio) were exposed to OLZ at concentrations of 35.5, 177.5, and 355.5μg/L. The results indicated that exposure to OLZ significantly increased body weight, total cholesterol (TC), low-density lipoprotein (LDL), and triglycerides (TG). Histological analysis revealed notable lipid accumulation in the liver. Furthermore, lipid synthesis genes, including sterol regulatory element binding protein (srebp), acetyl CoA carboxylase (acc), and fatty acid synthesis gene (fas), were up-regulated. In contrast, genes related to lipid decomposition, such as lipoprotein lipase (lpl), hormone-sensitive triglyceride lipase (hsl), and carnitine palmitoyltransferase 1b (cpt1b), were down-regulated. Subsequent analysis of zebrafish behavior showed reduced motor activity, sociability, and anxiety-like behavior in OLZ-exposed zebrafish, consistent with the results of neurotransmitter related gene expression. Following OLZ treatment, the expression of tryptophan hydroxylase (tph), tyrosine hydroxylase (th), dopamine transporter (dat), glutaminase (glsa), and glutamic acid decarboxylase 1b (gad1b) was upregulated. Additionally, the diversity of intestinal flora decreased after OLZ exposure, and the structure of the intestinal microbiota changed significantly compared to the control group. At the genus level, the abundance of Plesiomonas was upregulated, while the abundances of Bacillus and Cetobacterium were downregulated in the OLZ-exposed group. Furthermore, the results of the correlation analysis indicated that lipid metabolism and behavioral changes were closely associated with the microbiota. This study clarified the side effects of OLZ, and also provided a basis for the reasonable discharge concentration of OLZ in water and clinical drug use.

Ghrelin Promotes Lipid Uptake into White Adipose Tissue via Endothelial Growth Hormone Secretagogue-Receptor in Mice.

Background/Objectives: Endothelial peroxisome proliferator-activated receptor gamma (PPARγ) regulates adipose tissue by facilitating lipid uptake into white adipocytes, but the role of endothelial lipid transport in systemic energy balance remains unclear. Ghrelin conveys nutritional information through the central nervous system and increases adiposity, while deficiency in its receptor, growth hormone secretagogue-receptor (GHSR), suppresses adiposity on a high-fat diet. This study aims to examine the effect of ghrelin/GHSR signaling in the endothelium on lipid metabolism. Methods: We compared the effects of ghrelin on adiposity and lipid uptake into adipocytes in wild-type and GHSR-null mice. Transgenic mice expressing GHSR selectively in endothelial cells were also generated and compared with global GHSR-null and wild-type mice. The impact of ghrelin on lipid uptake-related genes was assessed in cultured endothelial cells. Results: Ghrelin increased adiposity and triglyceride clearance in wild-type but not in GHSR-null mice. GHSR-null mice showed higher serum triglyceride after olive oil gavage and lower white adipose tissue (WAT) weight on a high-fat diet, suggesting impaired lipid uptake. Restoring GHSR expression in endothelial cells increased lipoprotein lipase activity, lipid uptake into WAT, and WAT weight. Ghrelin enhanced free fatty acid uptake and the expression of lipid uptake genes in cultured endothelial cells, whereas these effects were absent in GHSR-null mice-derived endothelial cells. Knockdown of PPARγ revealed that ghrelin/GHSR signaling in endothelial cells promoted lipid uptake via endothelial PPARγ. Conclusions: Endothelial GHSR is key for regulating lipid metabolism via PPARγ in response to ghrelin and for the role of endothelium in regulating white adipocyte metabolism. Targeting endothelial ghrelin signaling may be a promising therapeutic approach for managing excessive adiposity and associated metabolic disorders.

Experimental Validation of Antiobesogenic and Osteoprotective Efficacy of Ginsenoside CK via Targeting Lipid and Atherosclerosis Pathways.

The present study explored the possible antiobesogenic and osteoprotective properties of the gut metabolite ginsenoside CK to clarify its influence on lipid and atherosclerosis pathways, thereby validating previously published hypotheses. These hypotheses were validated by harvesting and cultivating 3T3-L1 and MC3T3-E1 in adipogenic and osteogenic media with varying concentrations of CK. We assessed the differentiation of adipocytes and osteoblasts in these cell lines by applying the most effective doses of CK that we initially selected. Using 3T3-L1 adipocytes in vitro assessments, CK could effectively decrease intracellular lipid accumulation, inhibit α-glucosidase enzyme, increase 2-NBDG glucose uptake, reduce inflammation-associated cytokines (TNFα, and IL-6), adipogenic regulatory genes (PPARγ, FAS, C/EBPα), lipogenic gene LPL, and increase the expression of thermogenic gene UCP1. Additionally, CK treatment induced osteoblast development in MC3T3-E1 cells as shown by increased mineralization and calcium distribution, collagen content, alkaline phosphatase activity, and decreased inflammatory cytokines TNFα, and IL-6 and increased the regulated expressions of osteogenic genes including Runx2, ALP, BGLAP, OCN, and Col1a1. Significantly, as a major inhibitory regulator, the TP53 gene was down-regulated in both 3T3-L1 and MC3T3E1 cells after the treatment of CK. These encouraging results demonstrate the possible use of CK as an innovative treatment for controlling obesity and osteoporosis, targeting the underlying mechanisms of obesogenic and bone loss. Further studies are necessary to explore the clinical implications of these results and the potential of CK in future treatment strategies. This research highlights the promise of CK in addressing significant health issues.

Effects of Long-Term Serum Starvation on Autophagy, Metabolism, and Differentiation of Porcine Skeletal Muscle Satellite Cells.

This study investigated the effects of long-term serum starvation on autophagy, metabolism, and differentiation of porcine skeletal muscle satellite cells (SMSCs) and elucidated the role of autophagy in skeletal muscle development. Our findings provide a theoretical basis for improving meat production in domestic pigs. The SMSCs isolated and preserved in our laboratory were revived and divided into six groups based on the culture medium serum concentration to simulate varying levels of serum starvation: 20% serum (control group), 15% serum (mild serum starvation group), 5% serum (severe serum starvation group), and their autophagy inhibition groups supplemented with 3-methyladenine. After 96 h of culture, the apoptosis rate, mitochondrial membrane potential, reactive oxygen species, and ATP were measured to evaluate the effects of serum starvation on the SMSCs' metabolism. Additionally, the levels of autophagy-related proteins, autophagosomes, and autolysosomes were measured to investigate the impact of long-term serum starvation on autophagy. The expression of proteins associated with myogenic and adipogenic differentiation (MHC, MyoD1, peroxisome proliferator-activated receptor γ, and lipoprotein lipase) as well as lipid content were also determined to investigate the effects of long-term serum starvation on SMSC differentiation. The results showed that long-term serum starvation induced autophagy through the AMPK/mTOR signaling pathway, accelerated cell metabolism and apoptosis, exacerbated reactive oxygen species accumulation, and inhibited myogenic and adipogenic differentiation of SMSCs. Moreover, these effects were positively correlated with the level of serum starvation. In addition, serum starvation-induced autophagy moderately promoted the myogenic and adipogenic differentiation of SMSCs; however, these effects were insufficient to counteract the inhibition of cell differentiation by long-term serum starvation. This study provides insight into leveraging serum starvation as a stressor to regulate muscle growth and metabolism in domestic pigs.

Lipoprotein Lipase and Neurological Health: Investigating its Impact on Brain Function and Alzheimer's Disease

Lipoprotein Lipase (LPL) is an essential lipid metabolism enzyme affecting both the brain and peripheral tissues. Its impact on neuronal lipid homeostasis, synaptic function, and plasticity is increasingly recognized. This review explores the various functions of LPL in the brain and how it may affect neurological health, especially in Alzheimer's disease. We explore how LPL regulates lipid uptake and utilization in the brain, its influence on synaptic function, neurogenesis, and myelination, and its role in the pathophysiology of AD. Genetic and environmental factors modulating LPL activity are also discussed. The review provides insights into LPL's role in neurodegenerative diseases, acknowledges current limitations and challenges in research, and highlights the therapeutic potential of targeting LPL for AD treatment. Ultimately, this review underscores the importance of LPL in maintaining brain health and its promising potential as a therapeutic target for AD.

DISORDER OF LIPID METABOLISM IN CHRONIC KIDNEY DISEASE

Chronic kidney disease is a proven risk factor for the development and progression of lipid metabolism disorders. These disorders are based on an increase in the blood plasma content of cholesterol, triglycerides, low—density lipoproteins and a decrease in the level of high-density lipoproteins, apoproteins of the A family (ApoA-I and ApoA-II). There is a decrease in the activity of enzymes: lipoprotein lipase, hepatic triglyceride lipase, lecithin-cholesterol-acetyltransferase.

Differential effects of volanesorsen on apoC-III, triglycerides and pancreatitis in familial chylomicronemia syndrome diagnosed by genetic or non-genetic criteria.

Familial chylomicronemia syndrome (FCS) is diagnosed by genetic or non-genetic criteria. To assess responses to treatment of apolipoprotein (apo)C-III, triglycerides, and pancreatitis events in patients with FCS-based diagnostic methods. APPROACH enrolled 66 patients with FCS randomized to volanesorsen or placebo for 12 months. In 50 participants, genetic confirmation of FCS was based on the presence of pathogenic bi-allelic variants in LPL, APOC2, APOA5, GPIHBP1, or LMF1 genes. In 16 participants without a genetic diagnosis, FCS was diagnosed using clinical criteria and post-heparin lipoprotein lipase activity ≤20 % of normal. Plasma levels of apoC-III, triglycerides and related variables were measured at 3, 6 and 12 months. No significant differences were present in mean apoC-III reductions with volanesorsen at 3, 6 or 12 months in patients with FCS diagnosed either genetically or non-genetically. In contrast, the triglyceride reductions were statistically less robust in patients with genetic diagnosis at each timepoint, with mean (95 % confidence interval) percent reduction in triglycerides of -68.7 % (-78.7, -58.6) vs. -84.0 % (-99.4, -68.6), p = 0.014 at Month 3; -58.2 % (-78.1, -38.2) vs. -84.5 % (-122.4, -46.7), p = 0.009 at Month 6; and -35.6 % (-57.7, -13.4) vs. -69.0 % (-105.0, -33.1), p = 0.005 at Month 12. Patients with a genetic diagnosis had significantly lower response rates for achieved triglycerides <500 mg/dL, <750 mg/dL, <880 mg/dL and <1000 mg/dL than patients with a non-genetic diagnosis. All 5 episodes of acute pancreatitis occurred in patients with a genetic diagnosis. For a similar reduction in apoC-III in response to volanesorsen, triglyceride reduction is attenuated in patients with genetically versus non-genetically diagnosed FCS.

Genetic correlation between genes targeted by lipid-lowering drugs and venous thromboembolism: A drug-target Mendelian randomization study.

Dyslipidemia has been established as a potential risk factor for venous thromboembolism (VTE) in several observational studies. Statins and novel lipid-modifying agents are being explored for their potential in VTE prevention, encompassing deep vein thrombosis (DVT), and pulmonary embolism (PE). Nonetheless, conclusive evidence supporting the effectiveness remains uncertain. Without definitive proof, the current recommendation of lipid-lowering drugs (LLDs) for preventing VTE, either primarily or secondarily, is not support. An investigation into the impact of 8 classes of LLDs on VTE was conducted using a drug-target Mendelian randomization approach. The drug categories examined included 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), apolipoprotein B, proprotein convertase subtilisin/kexin type 9, Niemann-Pick C1-like 1, lipoprotein lipase (LPL), angiopoietin-like 3, apolipoprotein C3 (APOC3), and peroxisome proliferator-activated receptor alpha. Leveraging genetic variants situated proximate to or within drug-target genes linked with low-density lipoprotein and triglycerides, we acted as proxies for LLDs. The UK Biobank study was the source of data on VTE, PE, and DVT of lower extremities (LEDVT). We employed the inverse-variance weighted method for the core analysis in Mendelian randomization, complemented by sensitivity analysis to investigate horizontal pleiotropy and heterogeneity. Employing genetic proxies to inhibit HMGCR revealed a notable correlation with reduced LEDVT risk (odds ratio [OR]: 0.995, 95% CI: 0.992-0.998, P = .002), VTE (OR: 0.994, 95% CI: 0.988-1.000, P = .033), but a no significant association with PE (OR: 1.000, 95% CI: 0.994-1.002, P = .246). The suppression of APOB was linked with an elevated risk of experiencing LEDVT (OR: 1.002, 95% CI: 1.001-1.004, P = .006), VTE (OR: 1.005, 95% CI: 1.002-1.007, P < .001), and PE (OR: 1.002, 95% CI: 1.000-1.004, P = .031). Similarly, the activation of LPL was associated with increased risks for VTE (OR: 1.003, 95% CI: 1.001-1.005, P = .003) and PE (OR: 1.003, 95% CI: 1.002-1.005, P < .001). Additionally, the inhibition of APOC3 was linked to a higher DVT risk (OR: 1.002, 95% CI: 1.000-1.004, P = .038). Research has shown that HMGCR, out of 8 lipid-lowering drug-targets evaluated, exhibited a significant correlation with VTE and LEDVT, highlighting its potential as an effective target for the treatment or prevention of these conditions. In contrast, APOB, LPL, and APOC3 each contribute to an increased risk of VTE, PE, and LEDVT in various degrees, pharmacovigilance for VTE, PE, and LEDVT risk among users of APOB inhibitors, LPL activation, and APOC3 inhibitors may be warranted.

A Case of Glucokinase Maturity-Onset Diabetes of the Young Combined with Heterozygous Lipoprotein Lipase Deficiency.

A Case of Glucokinase Maturity-Onset Diabetes of the Young Combined with Heterozygous Lipoprotein Lipase Deficiency.

Optimizing treatment of cardiovascular risk factors in cerebral small vessel disease using genetics.

Cerebral small vessel disease (cSVD) causes lacunar stroke (LS), intracerebral haemorrhage, and is the most common pathology underlying vascular dementia. However, there are few trials examining whether treating conventional cardiovascular risk factors reduce stroke risk in cSVD, as opposed to stroke as a whole. We used Mendelian randomization techniques to investigate which risk factors are causally related to cSVD and to evaluate whether specific drugs may be beneficial in cSVD prevention. We identified genetic proxies for blood pressure traits, lipids, glycaemic markers, anthropometry measures, smoking, alcohol consumption, and physical activity from large-scale genome-wide association studies of European ancestry. We also selected genetic variants as proxies for drug target perturbation in hypertension, dyslipidaemia, hyperglycaemia, and obesity. Mendelian randomization was performed to assess their associations with LS from the GIGASTROKE Consortium (n = 6811) and in a sensitivity analysis in a cohort of patients with MRI-confirmed LS (n = 3306). We also investigated associations with three neuroimaging features of cSVD, namely, white matter hyperintensities (n = 55 291), fractional anisotropy (n = 36 460), and mean diffusivity (n = 36 012). Genetic predisposition to higher systolic and diastolic blood pressure was associated with LS and cSVD imaging markers. Genetically predicted liability to diabetes, obesity, smoking, higher triglyceride levels, and the ratio of triglycerides to high density lipoprotein (HDL) also showed detrimental associations with LS risk, while genetic predisposition to higher HDL concentrations and moderate-to-vigorous physical activity showed protective associations. Genetically proxied blood pressure-lowering through calcium channel blockers (CCBs) was associated with cSVD imaging markers, while genetically proxied HDL-raising through Cholesteryl Ester Transfer Protein (CETP) inhibitors, triglyceride-lowering through lipoprotein lipase (LPL), and weight-lowering through gastric inhibitory polypeptide receptor (GIPR) were associated with lower risk of LS. Our findings highlight the importance of some conventional cardiovascular risk factors, including blood pressure and BMI, in cSVD, but not other e.g. LDL. The findings further demonstrate the potential beneficial effects of CCBs on cSVD imaging markers and CETP inhibitors, LPL enhancement, and GIPR obesity-targeted drugs on LS. They provide useful information for initiating future clinical trials examining secondary prevention strategies in cSVD.

Genetic Variants in Severe Hypertriglyceridemia Among Taiwanese Participants - Insights From Genome-Wide Association and Whole-Exome Sequencing Analyses.

There are limited data on the use of whole-exome sequencing (WES) to diagnose severe hypertriglyceridemia. Our aim was to identify candidate genes linked to triglyceride levels via a genome-wide association study (GWAS) and to recruit participants with severe hypertriglyceridemia for WES to assess allelic variants in the candidate genes. A GWAS was conducted involving 120,140 participants to identify lead loci associated with blood triglyceride levels. Following the identification of these lead loci, WES was performed on DNA samples from 29 participants with hypertriglyceridemia whose triglyceride levels exceeded 800 mg/dL to assess variations in the corresponding genes. In the GWAS of 120,140 participants, the apolipoprotein A5 (APOA5) locus on chromosome 11 showed the strongest association with blood triglyceride levels (lead single nucleotide polymorphism [SNP] rs2075291; P=3.07×10-108), along with 5 independent SNPs (most significant P=7.84×10-167). Other key loci included BUD13 homolog (BUD13; P=2.73×10-62), glucokinase regulator (GCKR; P=2.63×10-24), and lipoprotein lipase (LPL; P=1.50×10-11). WES in 29 hypertriglyceridemia patients identified additional genes, including ALDH1A2, APOC1, LPL, RGS7, and SIK3, showing significant allele frequency variations and potential roles in lipid metabolism. Our study confirms the role of known genetic loci in triglyceride metabolism and hypertriglyceridemia while uncovering novel loci, offering new perspectives on lipid regulation and potential avenues for therapeutic advancements.

ABCG1 orchestrates adipose tissue macrophage plasticity and insulin resistance in obesity by rewiring saturated fatty acid pools.

The mechanisms governing adipose tissue macrophage (ATM) metabolic adaptation during diet-induced obesity (DIO) are poorly understood. In obese adipose tissue, ATMs are exposed to lipid fluxes, which can influence the activation of specific inflammatory and metabolic programs and contribute to the development of obesity-associated insulin resistance and other metabolic disorders. In the present study, we demonstrate that the membrane ATP-binding cassette g1 (Abcg1) transporter controls the ATM functional response to fatty acids (FAs) carried by triglyceride-rich lipoproteins, which are abundant in high-energy diets. Mice genetically lacking Abcg1 in the myeloid lineage presented an ameliorated inflammatory status in adipose tissue and reduced insulin resistance. Abcg1-deficient ATMs exhibited a less inflammatory phenotype accompanied by a low bioenergetic profile and modified FA metabolism. A closer look at the ATM lipidome revealed a shift in the handling of FA pools, including a redirection of saturated FAs from membrane phospholipids to lipid droplets, leading to a reduction in membrane rigidity and neutralization of proinflammatory FAs. ATMs from human individuals with obesity presented the same reciprocal relationship between ABCG1 expression and this inflammatory and metabolic status. Abolition of this protective, anti-inflammatory phenotype in Abcg1-deficient ATMs was achieved through restoration of lipoprotein lipase (Lpl) activity, thus delineating the importance of the Abcg1/Lpl axis in controlling ATM metabolic inflammation. Overall, our study identifies the rewiring of FA pools by Abcg1 as a major pathway orchestrating ATM plasticity and insulin resistance in DIO.

Investigating the Effects of Dietary Bile Acids on Production Performance and Lipid Metabolism in Late-Phase Laying Hens.

Multiply adverse effects including declines in production performance and excessive fat deposition were noticed with the extension of the laying cycle in hens, which are pertinent to animal welfare and human food safety. This study aimed to investigate the effect of dietary supplementation of bile acids (BAs) on production performance and lipid metabolism in late-phase laying hens. A total of 144 70-week-old hens were distributed into three treatments with eight replicates per treatment, including the basal diet with 0 (Ctrl), 95.01 (Low-BA), and 189.99 mg/kg (High-BA) of porcine BAs, respectively. The test period was from 70 to 75 weeks. The supplementation of BAs did not significantly alter laying performance during the trial, whereas it increased (p < 0.05) the total follicles compared to the Ctrl diet. The eggs from the hens fed the BA diet exhibited increased (p > 0.05) relative weight of eggshell and yolk color than those that consumed the Ctrl diet. There were no significant changes following BA treatment regarding the serum lipid profile. Dietary BA treatment reduced the total triglyceride in livers to different extents, resulting in the decreased diameter and area of vacuoles in liver tissues. The low-dose BA treatment decreased the mRNA levels of fatty acid synthase (FASN) and stearoyl-CoA desaturase (SCD), while promoting the expression of lipoprotein lipase (LPL) compared to the Ctrl group (both p < 0.05). Of note, the expressions of farnesoid X receptor (FXR), apical sodium-dependent bile acid transporter (ASBT), and ileum bile acid-binding protein (IBABP) were notably downregulated (p < 0.05) by the low-dose BA treatment. Dietary BA treatment had no apparent effects on laying performance, whereas it increased the follicle frequency, eggshell weight, and yolk color. Moreover, a diet containing 95.01 mg/kg of BAs depressed ileal BA resorption and hepatic fatty deposition by reducing lipogenesis and promoting lipolysis, which may have a beneficial effect on the liver in late-phase layers.

The Influence of Dietary n-3 Highly Unsaturated Fatty Acids on Growth, Fatty Acid Profile, Lipid Metabolism, Inflammatory Response, and Intestinal Microflora in F2 Generation Female Yangtze Sturgeon (Acipenser dabryanus).

DHA and EPA, as indispensable n-3 highly unsaturated fatty acids (HUFAs), exert a fundamental influence on regulating fish growth, lipid metabolism, and overall well-being. However, there is a notable lack of data concerning their effects on the F2 female generation of Yangtze sturgeon. Over a ten-month period, this study assessed the impacts of various dietary concentrations of n-3 HUFAs (0.5%, 1.0%, 1.5%, 2.0%, and 2.4%) on growth, fatty acid composition, lipid metabolism, inflammatory response, and intestinal microbiota in the F2 female generation of Yangtze sturgeon. Seventy-five test fish, with an average body weight of 3.60 ± 0.83 kg, were housed in 15 ponds, with each dietary group being assigned to three ponds. The results indicated that the 1.0%~1.5% n-3 HUFA group was characterized by the highest values of weight gain rate; serum triglyceride levels peaked in the 0.5% n-3 HUFA group. The fatty acid profiles of the fish tissues closely mirrored those of the diets. Specifically, compared to the 1.5% and 2.0% n-3 HUFA groups, the diet containing 2.4% n-3 HUFA down-regulated the mRNA expression of transforming growth factor beta, and, compared to the 0.5% and 1.0% n-3 HUFA groups, the 2.0% n-3 HUFA diet up-regulated the mRNA expression of nuclear factor kappa B. Conversely, compared to the 0.5% n-3 HUFA group, 2.0% n-3 HUFA in the diet up-regulated the gene mRNA expression of fatty acid binding protein 1 and fatty acid synthase. Compared to the 0.5% n-3 HUFA group, 1.0% n-3 HUFA in the diet up-regulated the gene mRNA expression of lipoprotein lipase. The α-diversity indices (ACE, PD_whole tree, Richness, and Chao1) exhibited an upward trend with increasing dietary n-3 HUFA levels, and the 2.4% n-3 HUFA group reached the highest values. At the phylum level, Fusobacteriota, Proteobacteria, Firmicutes, and Bacteroidota were the primary dominant phyla. Cetobacterium was the dominant genus in all groups. Collectively, these findings underscore that moderate dietary supplementation of n-3 HUFA (1.3%) is optimal and does not impair growth. The deposition of fatty acids in muscle and ovarian tissues, as well as the mRNA expression of lipid-metabolism genes, are closely associated with the dietary n-3 HUFA content. High levels of n-3 HUFA did not suppress intestinal α-diversity. These discoveries provide novel insights into the regulation of growth, lipid metabolism, and health in the F2 female generation of Yangtze sturgeon and offer a nutritional strategy for the artificial conservation of this endangered species.

Ameliorative effect of phenolic compound-pterostilbene on corticosterone-induced hepatic lipid metabolic disorder in broilers

The aim of this study was to investigate the ameliorative effects of pterostilbene (PTE), a polyphenolic compound, on stress-induced lipid metabolic disorders in the liver of broiler chickens. Six hundred healthy, one-day-old Arbor Acres (AA) with similar weight were randomly assigned to five groups, each consisting of 8 replicates with 15 broilers per replicate. The groups included: a control group (fed a basal diet), and four groups treated with corticosterone (CORT) at varying dietary levels of PTE supplementation: CORT (0 mg/kg PTE), CORT-PT200 (200 mg/kg PTE), CORT-PT400 (400 mg/kg PTE), and CORT-PT600 (600 mg/kg PTE). The results indicated that PTE administration to corticosterone (CORT)-injected broilers significantly improved weight gain, reduced liver index, and lowered the elevation of serum AST, GGT, Glu, TC, TG, and LDL-c concentrations induced by CORT injection (P < 0.05), but had no significant effect on serum CORT concentration (P > 0.05). PTE also significantly reduced the increased rate of abdominal fat deposition induced by CORT, decreased the average size of adipocytes, and downregulated the expression of the FAS gene (P < 0.05). It reversed the increase in liver TC, TG, LDL-c, and NEFA content induced by CORT (P < 0.05). PTE had no significant effect on the expression of the glucocorticoid receptor GR (P > 0.05), but significantly upregulated the protein expression of Sirt1 and p-AMPK (P < 0.05), promoted the expression of lipid autophagy genes MAP1LC3B and lipolytic genes LPL, but inhibited the expression of fatty acid synthesis genes SREBP-1c, ACC, and SCD (P < 0.05). The addition of PTE to the diet alleviated CORT-induced oxidative stress and inflammation by enhancing T-SOD and GSH-Px activities, reducing MDA content, inhibiting p-NF-κB p65 and NLRP3 expression and the release of TNF-α and IL-1β in the serum, and increasing IL-4 content (P < 0.05). Overall, dietary PTE effectively regulates lipid metabolism and antioxidant status, offering a potential strategy to mitigate stress-induced metabolic disruptions in broilers.