Low Levels of IgM Recognizing 4-Hydroxy-2-Nonenal-Modified Apolipoprotein A-I Peptide and Its Association with the Severity of Coronary Artery Disease in Taiwanese Patients.

Autoantibodies against apolipoprotein A-I (ApoA-I) are associated with cardiovascular disease risks. We aimed to examine the 4-hydroxy-2-nonenal (HNE) modification of ApoA-I in coronary artery disease (CAD) and evaluate the potential risk of autoantibodies against their unmodified and HNE-modified peptides. We assessed plasma levels of ApoA-I, HNE-protein adducts, and autoantibodies against unmodified and HNE-peptide adducts, and significant correlations and odds ratios (ORs) were examined. Two novel CAD-specific HNE-peptide adducts, ApoA-I251-262 and ApoA-I70-83, were identified. Notably, immunoglobulin G (IgG) anti-ApoA-I251-262 HNE, IgM anti-ApoA-I70-83 HNE, IgG anti-ApoA-I251-262, IgG anti-ApoA-I70-83, and HNE-protein adducts were significantly correlated with triglycerides, creatinine, or high-density lipoprotein in CAD with various degrees of stenosis (<30% or >70%). The HNE-protein adduct (OR = 2.208-fold, p = 0.020) and IgM anti-ApoA-I251-262 HNE (2.046-fold, p = 0.035) showed an increased risk of progression from >30% stenosis in CAD. HNE-protein adducts and IgM anti-ApoA-I251-262 HNE may increase the severity of CAD at high and low levels, respectively.

HDL-C and apolipoprotein A-I are independently associated with skeletal muscle mitochondrial function in healthy humans.

Prior animal and cell studies have demonstrated a direct role of high-density lipoprotein (HDL) and apolipoprotein A-I (ApoA-I) in enhancing skeletal muscle mitochondrial function and exercise capacity. However, the relevance of these animal and cell investigations in humans remains unknown. Therefore, a cross-sectional study was conducted in 48 adults (67% female, 8% Black participants, age 39 ± 15.4 yr old) to characterize the associations between HDL measures, ApoA-I, and muscle mitochondrial function. Forearm muscle oxygen recovery time (tau) from postexercise recovery kinetics was used to assess skeletal muscle mitochondrial function. Lipoprotein measures were assessed by nuclear magnetic resonance. HDL efflux capacity was assessed using J774 macrophages, radiolabeled cholesterol, and apolipoprotein B-depleted plasma both with and without added cyclic adenosine monophosphate. In univariate analyses, faster skeletal muscle oxygen recovery time (lower tau) was significantly associated with higher levels of HDL cholesterol (HDL-C), ApoA-I, and larger mean HDL size, but not HDL cholesterol efflux capacity. Slower recovery time (higher tau) was positively associated with body mass index (BMI) and fasting plasma glucose (FPG). In multivariable linear regression analyses, higher levels of HDL-C and ApoA-I, as well as larger HDL size, were independently associated with faster skeletal muscle oxygen recovery times that persisted after adjusting for BMI and FPG (all P < 0.05). In conclusion, higher levels of HDL-C, ApoA-I, and larger mean HDL size were independently associated with enhanced skeletal muscle mitochondrial function in healthy humans.NEW & NOTEWORTHY Our study provides the first direct evidence supporting the beneficial role of HDL-C and ApoA-I on enhanced skeletal muscle mitochondrial function in healthy young to middle-aged humans without cardiometabolic disease.

Blood lipid profiles as a prognostic biomarker in idiopathic pulmonary fibrosis.

BACKGROUND: Dysregulation of lipid metabolism is implicated in the pathogenesis of idiopathic pulmonary fibrosis (IPF). However, the association between the blood lipid profiles and the prognosis of IPF is not well defined. We aimed to identify the impacts of lipid profiles on prognosis in patients with IPF. METHODS: Clinical data of 371 patients with IPF (145 and 226 in the derivation and validation cohorts, respectively), including serum lipid profiles (total cholesterol, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, apolipoprotein A-I [Apo A-I], and apolipoprotein B), were retrospectively collected. The association with mortality was analyzed using the Cox proportional hazard model. RESULTS: In the derivation cohort, the mean age was 67.5 years, 86.2% were men, and 30.3% died during the follow-up (median: 18.0 months). Non-survivors showed lower lung function and greater gender-age-physiology scores than survivors. Among the serum lipid profiles, the levels of triglyceride and Apo A-I were significantly lower in non-survivors than in survivors. In the multivariate Cox analysis, low Apo A-I levels (< 140 mg/dL) were independently associated with the risk of mortality (hazard ratio 3.910, 95% confidence interval 1.170-13.069; P = 0.027), when adjusted for smoking history, body mass index, GAP score, and antifibrotic agent use. In both derivation and validation cohorts, patients with low Apo A-I levels (< 140 mg/dL) had worse survival (median survival: [derivation] 34.0 months vs. not reached, P = 0.003; [validation] 40.0 vs. 53.0 months, P = 0.027) than those with high Apo A-I levels in the Kaplan-Meier survival analysis. CONCLUSIONS: Our results indicate that low serum Apo A-1 levels are an independent predictor of mortality in patients with IPF, suggesting the utility of serum Apo A-I as a prognostic biomarker in IPF.

ApoA1/HDL-C ratio as a predictor for coronary artery disease in patients with type 2 diabetes: a matched case-control study.

INTRODUCTION: This study investigated the possible relationship between the Apo lipoprotein A1 /high-density lipoprotein cholesterol (ApoA1/HDL-C) ratio and coronary artery disease (CAD) in patients with type 2 diabetes (T2D). METHODS: This was a matched case-control study of 482 patients with T2D in two groups of CAD and (n = 241) non-CAD (n = 241). The patients were classified into four quartiles according to the ApoA1/HDL-C ratio, and multivariate logistic regression analysis was performed to assess the relationship between ApoA1/HDL-C and CAD. ROC analysis was also conducted. RESULTS: This study showed that the ApoA1/HDL-C ratio has an independent association with CAD in individuals with T2D. The CAD group exhibited a significantly higher ApoA1/HDL-C ratio than those without CAD (p-value = 0.004). Moreover, the risk of CAD increased significantly across the ApoA1/HDL-C ratio quartiles, with the highest odds in the fourth quartile. The second quartile showed an odds ratio (OR) of 2.03 (p-value = 0.048) compared to the first. Moving to the third quartile, the OR increased to 2.23 (p-value = 0.023). The highest OR was noted in the fourth, reaching 3.41 (p-value = 0.001). Employing a cut-off value of 2.66 and an area under the curve (AUC) of 0.885, the ApoA1/HDL-C ratio predicts CAD among patients with T2D with a sensitivity of 75% and a specificity of 91% (p-value < 0.001). CONCLUSION: The current study revealed an independent association between ApoA1/HDL-C ratio and CAD in patients with T2D. This ratio can be a promising tool for predicting CAD during the follow-up of patients with T2D, aiding in identifying those at higher risk for CAD.

Increased Apolipoprotein B/Apolipoprotein A-I Ratio Is Associated With Decline in Lung Function in Healthy Individuals: The Kangbuk Samsung Health Study.

BACKGROUND: Lung dysfunction and high apolipoprotein B/apolipoprotein A-I (apoB/apoA-I) ratio are both recognized risk factors for cardiovascular disease. However, few studies have examined the association between the apoB/ApoA-I ratio and lung function. Therefore, we investigated whether this ratio is associated with decreased lung function in a large healthy cohort. METHODS: We performed a cohort study on 68,418 healthy Koreans (34,797 males, mean age: 38.1 years) who underwent a health examination in 2019. ApoB/apoA-I ratio was categorized into quartiles. Spirometric values at the fifth percentile in our population were considered the lower limit of normal (LLN), which was used to define lung function impairment. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs), using the lowest quartile as the reference, were estimated to determine lung function impairment. RESULTS: Mean apoB/apoA-I ratio was 0.67 ± 0.21. Subjects with the highest quartile of this ratio had the lowest predicted forced expiratory volume in one second (FEV1%) and forced vital capacity (FVC%) after controlling for covariates (P < 0.001). However, FEV1/FVC ratio was not significantly different among the four quartiles (P = 0.059). Compared with the lowest quartile (Q1, reference), the aORs (95% CI) for FEV1% < LLN across increasing quartiles (from Q2 to Q4) were 1.216 (1.094-1.351), 1.293 (1.156-1.448), and 1.481 (1.311-1.672) (P for trend < 0.001), respectively. Similarly, the aORs for FVC% < LLN compared with the reference were 1.212 (1.090-1.348), 1.283 (1.147-1.436), and 1.502 (1.331-1.695) with increasing quartiles (P for trend < 0.001). However, the aORs for FEV1/FVC < LLN were not significantly different among groups (P for trend = 0.273). CONCLUSION: High apoB/apoA-I ratio was associated with decreased lung function. However, longitudinal follow-up studies are required to validate our findings.

Synergistic Anti-Inflammatory Activity of Lipid-Free Apolipoprotein (apo) A-I and CIGB-258 in Acute-Phase Zebrafish via Stabilization of the apoA-I Structure to Enhance Anti-Glycation and Antioxidant Activities.

CIGB-258, a 3 kDa peptide from heat shock protein 60, exhibits synergistic anti-inflammatory activity with apolipoprotein A-I (apoA-I) in reconstituted high-density lipoproteins (rHDLs) via stabilization of the rHDL structure. This study explored the interactions between CIGB-258 and apoA-I in the lipid-free state to assess their synergistic effects in the structural and functional enhancement of apoA-I and HDL. A co-treatment of lipid-free apoA-I and CIGB-258 inhibited the cupric ion-mediated oxidation of low-density lipoprotein (LDL) and a lowering of oxidized species in the dose-responsive manner of CIGB-258. The co-presence of CIGB-258 caused a blue shift in the wavelength of maximum fluorescence (WMF) of apoA-I with protection from proteolytic degradation. The addition of apoA-I:CIGB-258, with a molar ratio of 1:0.1, 1:0.5, and 1:1, to HDL2 and HDL3 remarkably enhanced the antioxidant ability against LDL oxidation up to two-fold higher than HDL alone. HDL-associated paraoxonase activities were elevated up to 28% by the co-addition of apoA-I and CIGB-258, which is linked to the suppression of Cu2+-mediated HDL oxidation with the slowest electromobility. Isothermal denaturation by a urea treatment showed that the co-presence of CIGB-258 attenuated the exposure of intrinsic tryptophan (Trp) and increased the mid-points of denaturation from 2.33 M for apoA-I alone to 2.57 M for an apoA-I:CIGB-258 mixture with a molar ratio of 1:0.5. The addition of CIGB-258 to apoA-I protected the carboxymethyllysine (CML)-facilitated glycation of apoA-I with the prevention of Trp exposure. A co-treatment of apoA-I and CIGB-258 synergistically safeguarded zebrafish embryos from acute death by CML-toxicity, suppressing oxidative stress and apoptosis. In adult zebrafish, the co-treatment of apoA-I+CIGB-258 exerted the highest anti-inflammatory activity with a higher recovery of swimming ability and survivability than apoA-I alone or CIGB-258 alone. A co-injection of apoA-I and CIGB-258 led to the lowest infiltration of neutrophils and interleukin (IL)-6 generation in hepatic tissue, with the lowest serum triglyceride, aspartate transaminase, and alanine transaminase levels in plasma. In conclusion, the co-presence of CIGB-258 ameliorated the beneficial functionalities of apoA-I, such as antioxidant and anti-glycation activities, by enhancing the structural stabilization and protection of apoA-I. The combination of apoA-I and CIGB-258 synergistically enforced the anti-inflammatory effect against CML toxicity in embryos and adult zebrafish.

Engineering a New IFN-ApoA-I Fusion Protein with Low Toxicity and Prolonged Action.

Recombinant human interferon alpha-2b (rIFN) is widely used in antiviral and anticancer immunotherapy. However, the high efficiency of interferon therapy is accompanied by a number of side effects; this problem requires the design of a new class of interferon molecules with reduced cytotoxicity. In this work, IFN was modified via genetic engineering methods by merging it with the blood plasma protein apolipoprotein A-I in order to reduce acute toxicity and improve the pharmacokinetics of IFN. The chimeric protein was obtained via biosynthesis in the yeast P. pastoris. The yield of ryIFN-ApoA-I protein when cultivated on a shaker in flasks was 30 mg/L; protein purification was carried out using reverse-phase chromatography to a purity of 95-97%. The chimeric protein demonstrated complete preservation of the biological activity of IFN in the model of vesicular stomatitis virus and SARS-CoV-2. In addition, the chimeric form had reduced cytotoxicity towards Vero cells and increased cell viability under viral load conditions compared with commercial IFN-a2b preparations. Analysis of the pharmacokinetic profile of ryIFN-ApoA-I after a single subcutaneous injection in mice showed a 1.8-fold increased half-life of the chimeric protein compared with ryIFN.

Investigating the Effect of Aspirin on apoAI-Induced ATP Binding Cassette Transporter 1 Protein Expression and Cholesterol Efflux in Human Astrocytes.

Background: Neurons need a high amount of cholesterol to maintain the stability of their membrane-rich structures. Astrocytes synthesize and distribute cholesterol to neurons, and ABCA1 is a key mediator of cholesterol efflux to generate HDL for cholesterol transport in the brain. Several studies imply the effect of aspirin on ABCA1 expression in peripheral cells such as macrophages. Here, we compared the effect of aspirin with apoA-I on ABCA1 protein expression and cholesterol efflux in human astrocytes. Materials and Methods: Human astrocytes were cultured, and the effects of aspirin on the expression and protein levels of ABCA1 were investigated through RT-PCR and Western blot analysis. Additionally, the effect of co-treatment with apoA-I and aspirin on ABCA1 protein level and cholesterol efflux was evaluated. Results: Dose and time-course experiments showed that the maximum effect of aspirin on ABCA1 expression occurred at a concentration of 0.5 mM after 12 h of incubation. RT-PCR and western blot data showed that aspirin upregulates ABCA1 expression by up to 4.7-fold and its protein level by 67%. Additionally, co-treatment with aspirin and apoA-I increased cholesterol release from astrocytes, indicating an additive effect of aspirin on apoAI-mediated cholesterol efflux. Conclusions: The results suggest a potential role of aspirin in increasing ABCA1 expression and cholesterol efflux in astrocytes, similar to the effect of apoA-I. This indicates that aspirin could potentially regulate brain cholesterol balance and can be considered in certain neurological diseases, in particular in some neurological disorders related to cholesterol accumulation such as Alzheimer's disease.

Systemic delivery of mutant huntingtin lowering antisense oligonucleotides to the brain using apolipoprotein A-I nanodisks for Huntington disease.

Efficient delivery of therapeutics to the central nervous system (CNS) remains a major challenge for the treatment of neurological diseases. Huntington disease (HD) is a dominantly inherited neurodegenerative disorder caused by a CAG trinucleotide expansion mutation in the HTT gene which codes for a toxic mutant huntingtin (mHTT) protein. Pharmacological reduction of mHTT in the CNS using antisense oligonucleotides (ASO) ameliorates HD-like phenotypes in rodent models of HD, with such therapies being investigated in clinical trials for HD. In this study, we report the optimization of apolipoprotein A-I nanodisks (apoA-I NDs) as vehicles for delivery of a HTT-targeted ASO (HTT ASO) to the brain and peripheral organs for HD. We demonstrate that apoA-I wild type (WT) and the apoA-I K133C mutant incubated with a synthetic lipid, 1,2-dimyristoyl-sn-glycero-3-phosphocholine, can self-assemble into monodisperse discoidal particles with diameters <20 nm that transmigrate across an in vitro blood-brain barrier model of HD. We demonstrate that apoA-I NDs are well tolerated in vivo, and that apoA-I K133C NDs show enhanced distribution to the CNS and peripheral organs compared to apoA-I WT NDs following systemic administration. ApoA-I K133C conjugated with HTT ASO forms NDs (HTT ASO NDs) that induce significant mHTT lowering in the liver, skeletal muscle and heart as well as in the brain when delivered intravenously in the BACHD mouse model of HD. Furthermore, HTT ASO NDs increase the magnitude of mHTT lowering in the striatum and cortex compared to HTT ASO alone following intracerebroventricular administration. These findings demonstrate the potential utility of apoA-I NDs as biocompatible vehicles for enhancing delivery of mutant HTT lowering ASOs to the CNS and peripheral organs for HD.

Lipid exchange of apolipoprotein A-I amyloidogenic variants in reconstituted high-density lipoprotein with artificial membranes.

High-density lipoproteins (HDLs) are responsible for removing cholesterol from arterial walls, through a process known as reverse cholesterol transport. The main protein in HDL, apolipoprotein A-I (ApoA-I), is essential to this process, and changes in its sequence significantly alter HDL structure and functions. ApoA-I amyloidogenic variants, associated with a particular hereditary degenerative disease, are particularly effective at facilitating cholesterol removal, thus protecting carriers from cardiovascular disease. Thus, it is conceivable that reconstituted HDL (rHDL) formulations containing ApoA-I proteins with functional/structural features similar to those of amyloidogenic variants hold potential as a promising therapeutic approach. Here we explored the effect of protein cargo and lipid composition on the function of rHDL containing one of the ApoA-I amyloidogenic variants G26R or L174S by Fourier transformed infrared spectroscopy and neutron reflectometry. Moreover, small-angle x-ray scattering uncovered the structural and functional differences between rHDL particles, which could help to comprehend higher cholesterol efflux activity and apparent lower phospholipid (PL) affinity. Our findings indicate distinct trends in lipid exchange (removal vs. deposition) capacities of various rHDL particles, with the rHDL containing the ApoA-I amyloidogenic variants showing a markedly lower ability to remove lipids from artificial membranes compared to the rHDL containing the native protein. This effect strongly depends on the level of PL unsaturation and on the particles' ultrastructure. The study highlights the importance of the protein cargo, along with lipid composition, in shaping rHDL structure, contributing to our understanding of lipid-protein interactions and their behavior.

Lipid-mediated protein corona regulation with increased apolipoprotein A-I recruitment for glioma targeting.

Protein corona has long been a source of concern, as it might impair the targeting efficacy of targeted drug delivery systems. However, engineered up-regulating the adsorption of certain functional serum proteins could provide nanoparticles with specific targeting drug delivery capacity. Herein, apolipoprotein A-I absorption increased nanoparticles (SPC-PLGA NPs), composed with the Food and Drug Administration approved intravenously injectable soybean phosphatidylcholine (SPC) and poly (DL-lactide-co-glycolide) (PLGA), were fabricated for enhanced glioma targeting. Due to the high affinity of SPC and apolipoprotein A-I, the percentage of apolipoprotein A-I in the protein corona of SPC-PLGA NPs was 2.19-fold higher than that of nanoparticles without SPC, which made SPC-PLGA NPs have superior glioma targeting ability through binding to scavenger receptor class BI on blood-brain barrier and glioma cells both in vitro and in vivo. SPC-PLGA NPs loaded with paclitaxel could effectively reduce glioma invasion and prolong the survival time of glioma-bearing mice. In conclusion, we provided a good example of the direction of achieving targeting drug delivery based on protein corona regulation.

Apolipoprotein A-1 downregulation promotes basal-like breast cancer cell proliferation and migration associated with DNA methylation.

Apolipoprotein A-I (APOA1) performs different roles in different subtypes of breast cancer. It is hypothesized to function as a tumor suppressor in basal-like breast cancer (BLBC). However, the specific role of APOA1 in BLBC and its underlying mechanisms remain unknown. The findings of the present study demonstrated a positive correlation between the expression level of APOA1 and the overall survival of patients with BLBC. Ectopic expression of APOA1 effectively inhibits the proliferation and metastasis of BLBC cells in vitro, and these effects are closely related to DNA methylation. To the best of our knowledge, the present study is the first to report increased methylation of the promoter region and decreased methylation of the structural genes of APOA1 in BLBC cells. These alterations resulted in the downregulation of APOA1 expression and suppression of BLBC tumor growth. Collectively, the results of the present study suggested that APOA1 mRNA expression is negatively regulated by DNA methylation in BLBC. Therefore, low expression of APOA1 may be a potential risk biomarker to predict survival in patients with BLBC.

The association of the apolipoprotein B/A1 ratio and the metabolic syndrome in children and adolescents: a systematic review and meta-analysis.

Objectives: Metabolic syndrome (MetS) is a constellation of coexisting cardiovascular risk factors. This study aimed to assess the evidence for the association between the apolipoprotein B/A1 ratio, apolipoprotein B, and apolipoprotein A1, and the MetS in children and adolescents. Methods: The English electronic databases including PubMed, Embase, Web of Science, and Scopus were searched up to February 28, 2022. To ascertain the validity of eligible studies, modified JBI scale was used. Standardized mean differences (SMDs) with 95% confidence intervals (CIs) were pooled using the random-effects model to evaluate the association between the apolipoprotein B/A1 ratio, apolipoprotein B, and apolipoprotein A1 and the MetS. Heterogeneity amongst the studies was determined by the use of the Galbraith diagram, Cochran's Q-test, and I2 test. Publication bias was assessed using Egger's and Begg's tests. Results: From 7356 records, 5 studies were included in the meta-analysis, representing a total number of 232 participants with MetS and 1320 participants as control group. The results indicated that increased levels of apolipoprotein B/A1 ratio (SMD 1.26; 95% CI: 1.04, 1.47) and apolipoprotein B (SMD 0.75; 95% CI: 0.36, 1.14) and decreased levels of apolipoprotein A1 (SMD -0.53; 95% CI: -0.69, -0.37) are linked to the presence of MetS. The notable findings were, children and adolescents with MetS had elevated levels of the apolipoprotein B/A1 ratio, apolipoprotein B, and decreased levels of apolipoprotein A1. Conclusions: Our results suggest the need to evaluate the levels of apolipoproteins for detecting the risk of MetS in children and adolescents. Supplementary Information: The online version contains supplementary material available at 10.1007/s40200-023-01235-z.

Foam fractionation studies of recombinant human apolipoprotein A-I.

Apolipoprotein A-I (apoA-I), the primary protein component of plasma high-density lipoproteins (HDL), is comprised of two structural regions, an N-terminal amphipathic α-helix bundle domain (residues 1-184) and a hydrophobic C-terminal domain (residues 185-243). When a recombinant fusion protein construct [bacterial pelB leader sequence - human apoA-I (1-243)] was expressed in Escherichia coli shaker flask cultures, apoA-I was recovered in the cell lysate. By contrast, when the C-terminal domain was deleted from the construct, large amounts of the truncated protein, apoA-I (1-184), were recovered in the culture medium. Consequently, following pelB leader sequence cleavage in the E. coli periplasmic space, apoA-I (1-184) was secreted from the bacteria. When the pelB-apoA-I (1-184) fusion construct was expressed in a 5 L bioreactor, substantial foam production (~30 L) occurred. Upon foam collection and collapse into a liquid foamate, SDS-PAGE revealed that apoA-I (1-184) was the sole major protein present. Incubation of apoA-I (1-184) with phospholipid vesicles yielded reconstituted HDL (rHDL) particles that were similar in size and cholesterol efflux capacity to those generated with full-length apoA-I. Mass spectrometry analysis confirmed that pelB leader sequence cleavage occurred and that foam fractionation did not result in unwanted protein modifications. The facile nature and scalability of bioreactor-based apolipoprotein foam fractionation provide a novel means to generate a versatile rHDL scaffold protein.

No effect of liraglutide on high density lipoprotein apolipoprotein AI kinetics in patients with type 2 diabetes.

AIM: The catabolism of high density lipoprotein (HDL) apolipoprotein AI (apoAI) is accelerated in patients with type 2 diabetes (T2D), related to hypertriglyceridemia, insulin resistance and low plasma adiponectin levels. Since liraglutide is likely to partly correct these abnormalities, we hypothesized that it might have a beneficial effect on HDL apoAI kinetics in patients with T2D. METHODS: An in vivo kinetic study of HDL apoAI was performed in 10 patients with T2D before and after 6 months of treatment with 1.2 mg/day of liraglutide, using a bolus of l-[1-13C]leucine followed by a 16-hour constant infusion. RESULTS: Liraglutide reduced BMI (34.9 ± 4.7 vs 36.6 ± 4.9 kg/m2, P = 0.012), HbA1c (7.1 ± 1.1 vs 9.6 ± 2.6%, P = 0.003), HOMA-IR (5.5 ± 1.9 vs 11.6 ± 11.2, P = 0.003), fasting triglycerides (1.76 ± 0.37 vs 2.48 ± 0.69 mmol/l, P < 0.001) and triglycerides during kinetics (2.34 ± 0.81 vs 2.66 ± 0.65 mmol/l, P = 0.053). Plasma HDL cholesterol and adiponectin concentrations were unchanged (respectively 0.97 ± 0.26 vs 0.97 ± 0.19 mmol/l, P = 1; 3169 ± 1561 vs 2618 ± 1651 µg/l, P = 0.160), similar to triglyceride content in HDL (5.13 ± 1.73 vs 5.39 ± 1.07%, P = 0.386). Liraglutide modified neither HDL apoAI fractional catabolic rate (0.35 ± 0.11 vs 0.38 ± 0.11 pool/day, P = 0.375), nor its production rate (0.44 ± 0.13 vs 0.49 ± 0.15 g/l/day, P = 0.375), nor its plasma concentration (1.26 ± 0.19 vs 1.29 ± 0.14 g/l, P = 0.386). CONCLUSION: Six months of treatment with 1.2 mg/day of liraglutide had no effect on the kinetics of HDL apoAI in patients with T2D. The lack of decrease in triglyceride content in HDL related to an only moderate decrease in triglyceridemia, probably greatly explains these results. Insufficient improvement of insulin sensitivity and adiponectinemia may also be implied.

Inhibitory Effect of Apolipoprotein A-I on Eosinophils in Allergic Rhinitis in vitro and in vivo.

Purpose: Eosinophils have pivotal roles in the development of allergic rhinitis (AR) through the release of cytotoxic substances. Apolipoprotein A-I (Apo-AI) exhibits a strong inhibitory effect on eosinophil infiltration in allergic diseases. Nevertheless, the precise impact of Apolipoprotein A-I on eosinophils remains uncertain. Methods: Our study recruited a total of 15 AR children and 15 controls. The correlation between Apo-AI expression and the counts of blood eosinophils was examined. Flow cytometry was employed to assess the role of Apo-AI in eosinophil apoptosis and adhesion. The Transwell system was performed to conduct the migration assay. An animal model using AR mice was established to test the effect of Apo-AI on eosinophils. Results: Serum Apo-AI were negatively related to eosinophils counts and eosinophil chemotactic protein levels in AR. Apo-AI exerts a pro-apoptotic effect while also impeding the processes of adhesion, migration, and activation of eosinophils. The apoptosis triggered by Apo-AI was facilitated through the phosphoinositide 3-kinase (PI3K) pathway. The chemotaxis and activation of eosinophils, which are influenced by Apolipoprotein A-I, are regulated through the PI3K and MAPK signaling pathways. Apo-AI treated mice presented with decreased blood and nasal eosinophilic inflammation as well as down-regulated eosinophil related cytokines. Conclusion: Our findings provide confirmation that Apo-AI exhibits inhibitory effects on the function of eosinophils in allergic rhinitis. This suggests that Apo-AI holds potential as a therapeutic target for future treatment strategies.

Apolipoprotein A-I inhibited group II innate lymphoid cell response mediated by microRNA-155 in allergic rhinitis.

Background: Group 2 innate lymphoid cells (ILC2s) have been found to take part in type 2 inflammation by secreting TH2 cytokines. Apolipoprotein A-I (Apo-AI), a major structural and functional protein of high-density lipoproteins, has anti-inflammatory effects on neutrophils, monocytes, macrophages, and eosinophils. However, its effects on ILC2s are not well characterized. Objective: We aimed to investigate the effect of Apo-AI on the proliferation and function of ILC2s as well as its possible mechanism. Methods: The protein expression of Apo-AI and the percentage of ILC2s in peripheral blood between 20 allergic rhinitis patients and 20 controls were detected by ELISA and flow cytometry. The effect of Apo-AI and miR-155 on ILC2 proliferation and function was detected by tritiated thymidine incorporation and ELISA. Anima models were adopted to verify the effect of Apo-AI in vivo. Results: Elevated expression of Apo-AI was observed in allergic rhinitis patients. Apo-AI promotes ABCA1 expression by ILC2s, which can be inhibited by anti-Apo-AI. Apo-AI decreased ILC2 proliferation and the microRNA levels of GATA3 and RORα from ILC2s. The miR-155 overexpression promoted the upregulation of GATA3 and type II cytokines from ILC2s, while the addition of Apo-AI or miR-155 inhibitor significantly inhibited expression of GATA3 and type II cytokines by ILC2s. Apo-AI-/- mice showed as enhanced allergen-induced airway inflammation. The miR-155 inhibitor can reverse the enhanced allergen-induced airway inflammation in Apo-AI-/- mice, while miR-155 mimics can reverse the decreased allergen-induced airway inflammation in Apo-AI-treated mice. Conclusion: Apo-AI suppressed the proliferation and function of ILC2s through miR-155 in allergic rhinitis. Our data provide new insights into the mechanism of allergen-induced airway inflammation.

Anti-inflammatory mechanism of Apolipoprotein A-I.

Apolipoprotein A-I(ApoA-I) is a member of blood apolipoproteins, it is the main component of High density lipoprotein(HDL). ApoA-I undergoes a series of complex processes from its generation to its composition as spherical HDL. It not only has a cholesterol reversal transport function, but also has a function in modulating the inflammatory response. ApoA-I exerts its anti-inflammatory effects mainly by regulating the functions of immune cells, such as monocytes/macrophages, dendritic cells, neutrophils, and T lymphocytes. It also modulates the function of vascular endothelial cells and adipocytes. Additionally, ApoA-I directly exerts anti-inflammatory effects against pathogenic microorganisms or their products. Intensive research on ApoA-I will hopefully lead to better diagnosis and treatment of inflammatory diseases.

Associations of HDL-C and ApoA-I with Mortality Risk in PCI Patients Across Different hsCRP Levels.

Purpose: The association between high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A-I (ApoA-I) and cardiovascular risk in patients with coronary artery disease remains inconsistent. Recent investigations indicated potential dysfunctionality of HDL under inflammation. This study endeavors to explore whether the inflammatory status modifies the effects of HDL-C and ApoA-I on cardiovascular risk in individuals with percutaneous coronary intervention (PCI). Patients and Methods: Consecutive 10,724 PCI patients at Fuwai hospital in 2013 were enrolled. Inflammation status was defined by high-sensitivity C-reactive proteins (hsCRP) ≥ 2 mg/L. The study endpoint was cardiac mortality. Results: Among 9569 PCI patients eventually included, 225 (2.4%) cardiac mortality happened during 5 years. In hsCRP ≥ 2 mg/L group, an U-shaped curve was observed for HDL-C and multivariate Cox regression showed that elevated risks of cardiac mortality correlated to both the lowest quintile (hazard ratio [HR], 2.50; 95% confidence interval [CI], 1.32-4.71) and the highest quintile of HDL-C (HR, 2.28; 95% CI, 1.23-4.25). However, an L-shaped curve existed in ApoA-I, indicating only the lowest quintile level of ApoA-I was associated with an increased cardiac mortality risk (HR, 2.19; 95% CI, 1.28-3.75). Nevertheless, in hsCRP < 2 mg/L group, no significant correlations between HDL-C and ApoA-I and cardiac mortality risk were identified (both P > 0.05). Conclusion: In PCI patients with hsCRP ≥ 2 mg/L. both low and high HDL-C levels correlated with higher cardiac mortality risk (U-shaped), while only low ApoA-I levels were linked to elevated risk (L-shaped). However, in patients with hsCRP < 2 mg/L, neither HDL-C nor ApoA-I levels were associated with higher cardiac mortality risk. These findings shed light on the importance of considering inflammation status, particularly hsCRP levels, in managing HDL-C and ApoA-I levels, and suggest targeting elevated ApoA-I levels as a potential therapeutic approach for PCI patients with hsCRP ≥ 2 mg/L.

Deciphering thyroid function and CIMT: a Mendelian randomization study of the U-shaped influence mediated by apolipoproteins.

Background: Carotid Intima-Media Thickness (CIMT) is a key marker for atherosclerosis, with its modulation being crucial for cardiovascular disease (CVD) risk assessment. While thyroid function's impact on cardiovascular health is recognized, the causal relationship and underlying mechanisms influencing CIMT remain to be elucidated. Methods: In this study, Mendelian Randomization (MR) was employed to assess the causal relationship between thyroid function and CIMT. Thyroid hormone data were sourced from the Thyroidomics Consortium, while lipid traits and CIMT measurements were obtained from the UK Biobank. The primary analysis method was a two-sample MR using multiplicative random effects inverse variance weighting (IVW-MRE). Additionally, the study explored the influence of thyroid hormones on lipid profiles and assessed their potential mediating role in the thyroid function-CIMT relationship through multivariate MR analysis. Results: The study revealed that lower levels of Free Thyroxine (FT4) within the normal range are significantly associated with increased CIMT. This association was not observed with free triiodothyronine (FT3), thyroid-stimulating hormone (TSH), or TPOAb. Additionally, mediation analysis suggested that apolipoprotein A-I and B are involved in the relationship between thyroid function and CIMT. The findings indicate a potential U-shaped curve relationship between FT4 levels and CIMT, with thyroid hormone supplementation in hypothyroid patients showing benefits in reducing CIMT. Conclusion: This research establishes a causal link between thyroid function and CIMT using MR methods, underscoring the importance of monitoring thyroid function for early cardiovascular risk assessment. The results advocate for the consideration of thyroid hormone supplementation in hypothyroid patients as a strategy to mitigate the risk of carotid atherosclerosis. These insights pave the way for more targeted approaches in managing patients with thyroid dysfunction to prevent cardiovascular complications.