Overexpression of apolipoprotein A-I alleviates endoplasmic reticulum stress in hepatocytes

Golgi condensation causes intestinal lipid accumulation through HIF-1α-mediated GM130 ubiquitination by NEDD4

The breakdown of Golgi proteins disrupts lipid trafficking, leading to lipid accumulation in the small intestine. However, the causal mechanism of the effects of Golgi protein degradation on the Golgi structure related to lipid trafficking in the small intestine remains unknown. Here we find that Golgi protein degradation occurs under hypoxic conditions in high-fat-diet-fed mice. Hypoxia-induced degradation promotes structural changes in the Golgi apparatus, termed 'Golgi condensation'. In addition, hypoxia-inducible factor 1α (HIF-1α) activation enhances Golgi condensation through the ubiquitination and degradation of Golgi matrix protein 130 (GM130), which is facilitated by neural precursor cell expressed developmentally downregulated protein 4 (NEDD4). Golgi condensation upon exposure to hypoxia promotes lipid accumulation, apolipoprotein A1 retention and decreased chylomicron secretion in the intestinal epithelium. Golgi condensation and lipid accumulation induced by GM130 depletion are reversed by exogenous GM130 induction in the intestinal epithelium. Inhibition of either HIF-1α or NEDD4 protects against GM130 degradation and, thereby, rescues cells from Golgi condensation, which further increases apolipoprotein A1 secretion and lipid accumulation both in vivo and in vitro. Furthermore, the HIF-1α inhibitor PX-478 prevents Golgi condensation, which decreases lipid accumulation and promotes high-density lipoprotein secretion in high-fat-diet-fed mice. Overall, our results suggest that Golgi condensation plays a key role in lipid trafficking in the small intestine through the HIF-1α- and NEDD4-mediated degradation of GM130, and these findings highlight the possibility that the prevention of structural modifications in the Golgi apparatus can ameliorate intestinal lipid accumulation in obese individuals.

Overexpression of Apolipoprotein A-I Alleviates Insulin Resistance in MASLD Mice Through the PPARα Pathway

Insulin resistance (IR) is one of the important causes of metabolic dysfunction-associated steatotic liver disease (MASLD). Apolipoprotein A-I (apoA-I) is secreted primarily by hepatocytes and plays an essential role in reverse cholesterol transport. Our previous studies revealed that apoA-I can mitigate the progression of metabolic dysfunction-associated steatohepatitis (MASH). However, there is no clear evidence to explain the relationship between apoA-I and IR. Here, we investigated the effects of apoA-I overexpression on IR in both HepG2 cells and mice. In vitro experiment results revealed that apoA-I overexpression can promote cellular glucose uptake in oleic acid-induced IR in HepG2 cells. High-fat, high-cholesterol, and high-fructose diets were used to induce IR in mice. The results showed that apoA-I overexpression improved glucose tolerance, reduced serum insulin levels, and ameliorated IR in diet-induced MASLD mice. Moreover, apoA-I promoted the expression of peroxisome proliferator-activated receptor α (PPARα) in the nucleus both in vitro and in vivo. In conclusion, apoA-I could alleviate MASLD by reducing IR in mice and might exert this effect through the PPARα pathway.

Risk Factors for Non-Alcoholic Fatty Liver Disease in Patients with Bipolar Disorder: A Cross-Sectional Retrospective Study

Purpose

The co-morbidity of non-alcoholic fatty liver disease (NAFLD) in patients with bipolar disorder (BD) has a negative impact on patient treatment and prognosis. This study aimed to identify the prevalence of NAFLD in patients with BD and investigate the risk factors of NAFLD.

Patients and Methods

A total of 678 patients with BD were included in the study. Clinical data were obtained from the hospital's electronic health record system. Data included fasting blood glucose, alanine aminotransferase, triglycerides, aspartate aminotransferase, high-density lipoprotein cholesterol (HDL), alkaline phosphatase, total cholesterol, glutamine transpeptidase, uric acid, apolipoprotein A1, apolipoprotein B, and liver ultrasound findings.

Results

The prevalence of NAFLD was 43.66% in patients with BD. Significant differences in body mass index (BMI), mean age, diabetes prevalence, course of BD, fasting blood glucose, alanine aminotransferase, HDL, alkaline phosphatase, triglycerides, aspartate aminotransferase, uric acid, glutamine transpeptidase, apolipoprotein B, total cholesterol, and apolipoprotein A1 were seen between the groups (all P<0.01). Male sex, age, BMI, course of BD, alanine aminotransferase, fasting blood glucose, aspartate aminotransferase, diabetes, glutamine transpeptidase, total cholesterol, alkaline phosphatase, triglycerides, uric acid, apolipoprotein B, HDL, and apolipoprotein A1 levels were correlated with NAFLD (all P<0.05). In patients with BD, diabetes (OR=6.412, 95% CI=1.049-39.21), BMI (OR=1.398, 95% CI=1.306-1.497), triglycerides (OR=1.456, 95% CI=1.036-2.045), and apolipoprotein A1 (OR=0.272, 95% CI=0.110-0.672) were risk factors for NAFLD (all P<0.05).

Conclusion

Risk factors for NAFLD in patients with BD include diabetes, BMI, course of BD, and a low level of apolipoprotein A1. A proactive approach to disease management, such as appropriate physical activity and adoption of a healthy diet, and regular monitoring of changes in patient markers should be adopted to reduce the prevalence of NAFLD.

Identification and validation of an endoplasmic-reticulum-stress-related gene signature as an effective diagnostic marker of endometriosis

Background

Endometriosis is one of the most common benign gynecological diseases and is characterized by chronic pain and infertility. Endoplasmic reticulum (ER) stress is a cellular adaptive response that plays a pivotal role in many cellular processes, including malignant transformation. However, whether ER stress is involved in endometriosis remains largely unknown. Here, we aimed to explore the potential role of ER stress in endometriosis, as well as its diagnostic value.

Methods

We retrieved data from the Gene Expression Omnibus (GEO) database. Data from the GSE7305 and GSE23339 datasets were integrated into a merged dataset as the training cohort. Differentially expressed ER stress-related genes (DEG-ERs) were identified by integrating ER stress-related gene profiles downloaded from the GeneCards database with differentially expressed genes (DEGs) in the training cohort. Next, an ER stress-related gene signature was identified using LASSO regression analysis. The receiver operating characteristic curve was used to evaluate the discriminatory ability of the constructed model, which was further validated in the GSE51981 and GSE105764 datasets. Online databases were used to explore the possible regulatory mechanisms of the genes in the signature. Meanwhile, the CIBERSORT algorithm and Pearson correlation test were applied to analyze the association between the gene signature and immune infiltration. Finally, expression levels of the signature genes were further detected in clinical specimens using qRT-PCR and validated in the Turku endometriosis database.

Results

In total, 48 DEG-ERs were identified in the training cohort. Based on LASSO regression analysis, an eight-gene-based ER stress-related gene signature was constructed. This signature exhibited excellent diagnostic value in predicting endometriosis. Further analysis indicated that this signature was associated with a compromised ER stress state. In total, 12 miRNAs and 23 lncRNAs were identified that potentially regulate the expression of ESR1, PTGIS, HMOX1, and RSAD2. In addition, the ER stress-related gene signature indicated an immunosuppressive state in endometriosis. Finally, all eight genes showed consistent expression trends in both clinical samples and the Turku database compared with the training dataset.

Conclusions

Our work not only provides new insights into the impact of ER stress in endometriosis but also provides a novel biomarker with high clinical value.

Antibody against apolipoprotein-A1, non-alcoholic fatty liver disease and cardiovascular risk: a translational study

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a common liver disease increasing cardiovascular disease (CVD) morbidity and mortality. Autoantibodies against apolipoprotein A-1 (AAA-1) are a possible novel CVD risk factor promoting inflammation and disrupting cellular lipid homeostasis, two prominent pathogenic features of NAFLD. We explored the role of AAA-1 in NAFLD and their association with CVD risk.

METHODS

HepaRG cells and liver sections from ApoE-/- mice exposed to AAA-1 were used for lipid quantification and conditional protein expression. Randomly selected sera from 312 subjects of the Prevention of Renal and Vascular End-stage Disease (PREVEND) general population cohort were used to measure AAA-1. A Fatty Liver Index (FLI) ≥ 60 and a 10-year Framingham Risk Score (FRS) ≥ 20% were used as proxy of NAFLD and high CVD risk, respectively.

RESULTS

In-vitro and mouse models showed that AAA-1 increased triglyceride synthesis leading to steatosis, and promoted inflammation and hepatocyte injury. In the 112 PREVEND participants with FLI ≥ 60, AAA-1 were associated with higher FRS, alkaline phosphatase levels, lower HDL cholesterol and tended to display higher FLI values. Univariate linear and logistic regression analyses (LRA) confirmed significant associations between AAA-1, FLI and FRS ≥ 20%, while in adjusted LRA, FLI was the sole independent predictor of FRS ≥ 20% (OR: 1.05, 95%CI 1.01-1.09, P = 0.003). AAA-1 was not an independent FLI predictor.

CONCLUSIONS

AAA-1 induce a NAFLD-compatible phenotype in vitro and in mice. Intricate associations exist between AAA-1, CVD risk and FLI in the general population. Further work is required to refine the role of AAA-1 in NAFLD and to determine if the AAA-1 association with CVD is affected by hepatic steatosis.

High-density lipoproteins and non-alcoholic fatty liver disease

Background and aims

Non-alcoholic fatty liver disease (NAFLD), a high incidence liver pathology, is associated with a ∼1.5-fold higher cardiovascular disease risk. This phenomenon is generally attributed to the NAFLD-associated increase in circulating levels of pro-atherogenic apolipoprotein B100-containing small dense low-density lipoprotein and plasma hypertriglyceridemia. However, also a significant reduction in cholesterol transported by anti-atherogenic high-density lipoproteins (HDL) is frequently observed in subjects suffering from NAFLD as compared to unaffected people. In this review, we summarize data regarding the relationship between NAFLD and plasma HDL-cholesterol levels, with a special focus on highlighting potential causality between the NAFLD pathology and changes in HDL metabolism.

Methods and results

Publications in PUBMED describing the relationship between HDL levels and NAFLD susceptibility and/or disease severity, either in human clinical settings or genetically-modified mouse models, were critically reviewed for subsequent inclusion in this manuscript. Furthermore, relevant literature describing effects on lipid loading in cultured hepatocytes of models with genetic alterations related to HDL metabolism have been summarized.

Conclusions

Although in vitro observations suggest causality between HDL formation by hepatocytes and protection against NAFLD-like lipid accumulation, current literature remains inconclusive on whether relative HDL deficiency is actually driving the development of fatty liver disease in humans. In light of the current obesity pandemic and the associated marked rise in NAFLD incidence, it is of clear scientific and societal interest to gain further insight into the relationship between HDL-cholesterol levels and fatty liver development to potentially uncover the therapeutic potential of pharmacological HDL level and/or function modulation.

Current Therapeutical Approaches Targeting Lipid Metabolism in NAFLD

Nonalcoholic fatty liver disease (NAFLD, including nonalcoholic fatty liver (NAFL) and nonalcoholic steatohepatitis (NASH)) is a high-prevalence disorder, affecting about 1 billion people, which can evolve to more severe conditions like cirrhosis or hepatocellular carcinoma. NAFLD is often concomitant with conditions of the metabolic syndrome, such as central obesity and insulin-resistance, but a specific drug able to revert NAFL and prevent its evolution towards NASH is still lacking. With the liver being a key organ in metabolic processes, the potential therapeutic strategies are many, and range from directly targeting the lipid metabolism to the prevention of tissue inflammation. However, side effects have been reported for the drugs tested up to now. In this review, different approaches to the treatment of NAFLD are presented, including newer therapies and ongoing clinical trials. Particular focus is placed on the reverse cholesterol transport system and on the agonists for nuclear factors like PPAR and FXR, but also drugs initially developed for other conditions such as incretins and thyromimetics along with validated natural compounds that have anti-inflammatory potential. This work provides an overview of the different therapeutic strategies currently being tested for NAFLD, other than, or along with, the recommendation of weight loss.

Apolipoprotein A-I (ApoA-I) protects Nile tilapia (Oreochromis niloticus) against bacterial infection

Apolipoprotein A-I (ApoA-I) is a lipoprotein involved in a variety of physiological and pathological processes. However, the immunomodulatory functions of ApoA-I in fish are not well understood. In this study, ApoA-I from Nile tilapia (Oreochromis niloticus) (On-ApoA-I) was identified, and its function in bacterial infection was investigated. The open reading frame of On-ApoA-I is 792 bp, which codes for a protein containing 263 amino acids. On-ApoA-I shared over 60% sequence similarity with other teleost fish and more than 20% with mammalian ApoA-I. On-ApoA-I was found to be highly expressed in the liver and significantly induced during Streptococcus agalactiae infection by qRT‒PCR analysis. Furthermore, in vivo studies revealed that recombinant On-ApoA-I protein could suppress inflammation and apoptosis and improve the likelihood of surviving bacterial infection. Additionally, On-ApoA-I showed in vitro antimicrobial properties against Gram-positive and Gram-negative bacteria. These findings offer a theoretical basis for further investigations into the role of ApoA-I in fish immunology.

Advances in the study of the pathogenesis of obesity: Based on apolipoproteins

Obesity is a state presented by excessive accumulation and abnormal distribution of body fat, with metabolic disorders being one of its distinguishing features. Obesity is associated with dyslipidemia, apolipoproteins are important structural components of plasma lipoproteins, which influence lipid metabolism in the body by participating in lipoprotein metabolism and are closely related to the progression of obesity. Apolipoproteins influence the progression of obesity from lipid metabolism, energy expenditure and inflammatory response. In this review, we discuss the alterations of apolipoproteins in obesity, understand the potential mechanisms by which apolipoproteins affect obesity, as well as provide new targets for the treatment of obesity.

Association between apolipoprotein B/A1 and the risk of metabolic dysfunction associated fatty liver disease according to different lipid profiles in a Chinese population: A cross-sectional study

BACKGROUND AND AIM

Metabolic dysfunction associated fatty liver disease (MAFLD) is the most common liver disease and dyslipidemia is commonly considered a prominent risk factor for MAFLD. This study was to investigate the association between the apolipoprotein B/A1 (apo B/A1) ratio and the risk of MAFLD based on new diagnostic criteria.

METHODS

We conducted a cross-sectional study on 3341 participants. Restricted cubic spline (RCS) analyses, logistic regression, Synergistic effects analyses and stratified analyses were used to evaluate the association between the apo B/A1 ratio and the risk of MAFLD.

RESULTS

The apo B/A1 ratio was nonlinearly related to the increased risk of MAFLD and the OR and 95% CI for the apo B/A1 95th percentile was 1.700 (1.004-2.879) compared with the 50th percentile. Each 1 SD increase in apo B/A1 ratio would increase the 1.313-fold risk of the risk of MAFLD in all participants and 1.46-fold risk in normolipidemic participants. Synergistic effects indicated elevated Apo B/A1 ratio and dyslipidemia collectively contributed to an increased risk of MAFLD [OR (95 %CI): 2.496(1.869-3.334)].

CONCLUSIONS

The apo B/A 1 ratio was a risk factor of the presence of MAFLD. Dyslipidemia and elevated the Apo B/A1 ratio can synergistically contributed to the risk of MAFLD.

Plasma proteomics reveals crosstalk between lipid metabolism and immunity in dairy cows receiving essential fatty acids and conjugated linoleic acid

Essential fatty acids (EFA) and conjugated linoleic acids (CLA) are unsaturated fatty acids with immune-modulatory effects, yet their synergistic effect is poorly understood in dairy cows. This study aimed at identifying differentially abundant proteins (DAP) and their associated pathways in dairy cows supplied with a combination of EFA and CLA during the transition from antepartum (AP) to early postpartum (PP). Sixteen Holstein cows were abomasally infused with coconut oil as a control (CTRL) or a mixture of EFA (linseed + safflower oil) and CLA (Lutalin, BASF) (EFA + CLA) from − 63 to + 63 days relative to parturition. Label-free quantitative proteomics was performed on plasma samples collected at days − 21, + 1, + 28, and + 63. During the transition time, DAP, consisting of a cluster of apolipoproteins (APO), including APOE, APOH, and APOB, along with a cluster of immune-related proteins, were related to complement and coagulation cascades, inflammatory response, and cholesterol metabolism. In response to EFA + CLA, specific APO comprising APOC3, APOA1, APOA4, and APOC4 were increased in a time-dependent manner; they were linked to triglyceride-enriched lipoprotein metabolisms and immune function. Altogether, these results provide new insights into metabolic and immune adaptation and crosstalk between them in transition dairy cows divergent in EFA + CLA status.

Lipoprotein A, combined with alanine aminotransferase and aspartate aminotransferase, contributes to predicting the occurrence of NASH: a cross-sectional study

Background

Nonalcoholic steatohepatitis (NASH) progresses from simple nonalcoholic fatty liver (NAFL) and has a poor prognosis. Abnormal lipid metabolism is closely related to the occurrence and development of nonalcoholic fatty liver disease (NAFLD). This study aimed to study the relationships between serum lipid metabolites and NASH, and to improve the early diagnosis of NASH.

Methods

This study included 86 NAFLD patients (23 NASH and 63 NAFL), and 81 unaffected individuals as controls from West China Hospital between October 2018 and May 2019. With lipid metabolites as the focus of the study, the differences in lipid metabolites were compared between the control group, NAFL patients, and NASH patients. Logistic regression analysis was used to examine the risk factors of NASH. Finally, receiver operating characteristic curve (ROC curve) was used to analyze the efficacy of the metabolites in NASH prediction.

Results

The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lipoprotein A (LPA) increased with the severity of NAFLD. In NAFLD patients, LPA (OR:1.61; 95%CI: 1.03–2.52) was a potential risk factor for NASH, and ROC analysis showed that the combination of LPA, ALT, and AST had a greater predictive efficiency for NASH.

Conclusions

Abnormal apolipoprotein/lipoprotein is closely related to lipid metabolism disorder in patients with NAFLD. In NAFL, the combination of LPA, ALT, and AST contributes to predicting the occurrence of NASH. LPA may be a potential biomarker and therapeutic target for diagnosing and treating NASH.

The exchangeable apolipoproteins in lipid metabolism and obesity

Dyslipidemia, characterized by increased plasma levels of low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol (VLDL-C), triglyceride (TG), and reduced plasma levels of high-density lipoprotein cholesterol (HDL-C), is confirmed as a hallmark of obesity and cardiovascular diseases (CVD), posing serious risks to the future health of humans. Thus, it is important to understand the molecular metabolism of dyslipidemia, which could help reduce the morbidity and mortality of obesity and CVD. Currently, several exchangeable apolipoproteins, such as apolipoprotein A1 (ApoA1), apolipoprotein A5 (ApoA5), apolipoprotein E (ApoE), and apolipoprotein C3 (ApoC3), have been verified to exert vital effects on modulating lipid metabolism and homeostasis both in plasma and in cells, which consequently affect dyslipidemia. In the present review, we summarize the findings of the effect of exchangeable apolipoproteins on affecting lipid metabolism in adipocytes and hepatocytes. Furthermore, we also provide new insights into the mechanisms by which the exchangeable apolipoproteins influence the pathogenesis of dyslipidemia and its related cardio-metabolic disorders.

Apolipoprotein A-I improves hepatic autophagy through the AMPK pathway

Dysfunction in lipid metabolism may result in a decrease in hepatic autophagy, which contributes to the pathogenesis of non-alcoholic steatohepatitis. ATP-binding cassette transporter A1 transports free cholesterol and phospholipids to apolipoprotein A-I (apoA-I) to form nascent high-density lipoprotein particles. Results from previous studies showed that the overexpression of apoA-I significantly reduced levels of hepatic lipids and endoplasmic reticulum stress by modifying lipid transport. Here, we investigated the effects of apoA-I overexpression on hepatic autophagy in cultured hepatocytes and mice. The overexpression of apoA-I in HepG2 cells resulted in an increase in the levels of autophagy as well as the phosphorylation of AMP-activated protein kinase α (AMPKα) and ULK1 and a decrease in the phosphorylation of mammalian target of rapamycin (mTOR). An AMPK inhibitor and siRNA eliminated this apoA-I effect. Consistently, apoA-I transgenic mice showed increased autophagy and AMPKα phosphorylation. These results suggest that apoA-I overexpression alleviates steatohepatitis by increasing hepatic autophagy through the AMPK-mTOR-ULK1 pathway.

Knockout of apolipoprotein A-I decreases parenchymal and vascular β-amyloid pathology in the Tg2576 mouse model of Alzheimer's disease

AIMS

Apolipoprotein A-I (apoA-I), the principal apolipoprotein associated with high-density lipoproteins in the periphery, is also found at high concentrations in the cerebrospinal fluid. Previous studies have reported either no impact or vascular-specific effects of apoA-I knockout (KO) on β-amyloid (Aβ) pathology. However, the putative mechanism(s) by which apoA-I may influence Aβ deposition is unknown.

METHODS

We evaluated the effect of apoA-I deletion on Aβ pathology, Aβ production and clearance from the brain in the Tg2576 mouse model of Alzheimer's disease (AD).

RESULTS

Contrary to previous reports, deletion of the APOA1 gene significantly reduced concentrations of insoluble Aβ40 and Aβ42 and reduced plaque load in both the parenchyma and blood vessels of apoA-I KO × Tg2576 mice compared to Tg2576 animals. This was not due to decreased Aβ production or alterations in Aβ species. Levels of soluble clusterin/apoJ were significantly higher in neurons of apoA-I KO mice compared to both wildtype (WT) and apoA-I KO × Tg2576 mice. In addition, clearance of Aβ along intramural periarterial drainage pathways was significantly higher in apoA-I KO mice compared to WT animals.

CONCLUSION

These data suggest that deletion of apoA-I is associated with increased clearance of Aβ and reduced parenchymal and vascular Aβ pathology in the Tg2576 model. These results suggest that peripheral dyslipidaemia can modulate the expression of apolipoproteins in the brain and may influence Aβ clearance and aggregation in AD.

Targeted Interleukin-22 Gene Delivery in the Liver by Polymetformin and Penetratin-Based Hybrid Nanoparticles to Treat Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is now a leading cause of chronic liver disease, and there is currently no available treatment strategy. Interleukin-22 (IL-22) has been recognized as a promising agent for alleviating NAFLD, but the efficacy of IL-22 is far from satisfactory because safe dose of IL-22 elicited limited improvement, whereas higher concentration might induce serious side effects and off-target toxicities. Thus, targeted and sustained expression of IL-22 in the liver is necessary. To meet the challenge, we elaborately developed a novel polymetformin carrier by conjugating biguanide to chitosan, termed chitosan-metformin (CM), which could exert advanced gene delivery efficiency and possess intrinsic therapeutic efficacy from metformin for NAFLD. CM accompanied with penetratin and DSPE-PEG2000 could self-assemble to form stable nanocomplexes with IL-22 gene via electrostatic interaction. This nanoparticle (CDPIA) exerted desirable particle size at ∼100 nm, fine morphology, and efficient cellular internalization. Furthermore, CDPIA also demonstrated a unique superiority in endosomal escape capacity and satisfactory biocompatibility as well as predominant liver accumulation. Most importantly, CDPIA distinctly alleviated hepatic steatosis, restored insulin sensitivity, and improved metabolic syndrome in high-fat-diet-fed mice model. This liver-targeted delivery of IL-22 activated STAT3/Erk1/2 and Nrf2/SOD1 signaling transductions as well as modulated lipid-metabolism-related gene expression. These findings altogether demonstrated that the polymetformin and penetratin-based hybrid nanoparticles could be exploited as a novel safe and efficient strategy for the improvement of NAFLD.

Human ApoA-I Overexpression Enhances Macrophage-Specific Reverse Cholesterol Transport but Fails to Prevent Inherited Diabesity in Mice

Human apolipoprotein A-I (hApoA-I) overexpression improves high-density lipoprotein (HDL) function and the metabolic complications of obesity. We used a mouse model of diabesity, the db/db mouse, to examine the effects of hApoA-I on the two main functional properties of HDL, i.e., macrophage-specific reverse cholesterol transport (m-RCT) in vivo and the antioxidant potential, as well as the phenotypic features of obesity. HApoA-I transgenic (hA-I) mice were bred with nonobese control (db/+) mice to generate hApoA-I-overexpressing db/+ offspring, which were subsequently bred to obtain hA-I-db/db mice. Overexpression of hApoA-I significantly increased weight gain and the incidence of fatty liver in db/db mice. Weight gain was mainly explained by the increased caloric intake of hA-I-db/db mice (>1.2-fold). Overexpression of hApoA-I also produced a mixed type of dyslipidemia in db/db mice. Despite these deleterious effects, the overexpression of hApoA-I partially restored m-RCT in db/db mice to levels similar to nonobese control mice. Moreover, HDL from hA-I-db/db mice also enhanced the protection against low-density lipoprotein (LDL) oxidation compared with HDL from db/db mice. In conclusion, overexpression of hApoA-I in db/db mice enhanced two main anti-atherogenic HDL properties while exacerbating weight gain and the fatty liver phenotype. These adverse metabolic side-effects were also observed in obese mice subjected to long-term HDL-based therapies in independent studies and might raise concerns regarding the use of hApoA-I-mediated therapy in obese humans.