Inhibition of de novo ceramide synthesis by sirtuin-1 improves beta-cell function and glucose metabolism in type 2 diabetes.

AIMS: Obesity and type 2 diabetes (T2D) are major risk factors for cardiovascular (CV) diseases. Dysregulated pro-apoptotic ceramide synthesis reduces ß-cell insulin secretion, thereby promoting hyperglycaemic states that may manifest as T2D. Pro-apoptotic ceramides modulate insulin sensitivity and glucose tolerance while being linked to poor CV outcomes. Sirtuin-1 (SIRT1) is a NAD + -dependent deacetylase that protects against pancreatic ß-cell dysfunction; however, systemic levels are decreased in obese-T2D mice and may promote pro-apoptotic ceramide synthesis and hyperglycaemia. Herein, we aimed to assess the effects of restoring circulating SIRT1 levels to prevent metabolic imbalance in obese and diabetic mice. METHODS AND RESULTS: Circulating SIRT1 levels were reduced in obese-diabetic mice (db/db) as compared to age-matched non-diabetic db/+ controls. Restoration of SIRT1 plasma levels with recombinant murine SIRT1 for 4 weeks prevented body weight gain and improved glucose tolerance, insulin sensitivity, and vascular function in mice models of obesity and T2D. Untargeted lipidomics revealed that SIRT1 restored insulin secretory function of ß-cells by reducing synthesis and accumulation of pro-apoptotic ceramides. Molecular mechanisms involved direct binding to and deacetylation of Toll-like receptor 4 (TLR4) by SIRT1 in ß-cells, thereby decreasing the rate-limiting enzymes of sphingolipid synthesis SPTLC1/2 via AKT/NF-κB. Among patients with T2D, those with high baseline plasma levels of SIRT1 prior to metabolic surgery displayed restored ß-cell function (HOMA2-ß) and were more likely to have T2D remission during follow-up. CONCLUSION: Acetylation of TLR4 promotes ß-cell dysfunction via ceramide synthesis in T2D, which is blunted by systemic SIRT1 replenishment. Hence, restoration of systemic SIRT1 may provide a novel therapeutic strategy to counteract toxic ceramide synthesis and mitigate CV complications of T2D.

Chronic SIRT1 supplementation in diabetic mice improves endothelial function by suppressing oxidative stress.

AIMS: Enhancing SIRT1 activity exerts beneficial cardiovascular effects. In diabetes, plasma SIRT1 levels are reduced. We aimed to investigate the therapeutic potential of chronic recombinant murine SIRT1 (rmSIRT1) supplementation to alleviate endothelial and vascular dysfunction in diabetic mice (db/db). METHODS AND RESULTS: Left internal mammary arteries obtained from patients undergoing coronary artery bypass grafting with or without a diagnosis of diabetes were assayed for SIRT1 protein levels. Twelve-week-old male db/db mice and db/+ controls were treated with vehicle or rmSIRT1 intraperitoneally for 4 weeks, after which carotid artery pulse wave velocity (PWV) and energy expenditure/activity were assessed by ultrasound and metabolic cages, respectively. Aorta, carotid, and mesenteric arteries were isolated to determine endothelial and vascular function using the myograph system.Arteries obtained from diabetic patients had significantly lower levels of SIRT1 relative to non-diabetics. In line, aortic SIRT1 levels were reduced in db/db mice compared to db/+ mice, while rmSIRT1 supplementation restored SIRT1 levels. Mice receiving rmSIRT1 supplementation displayed increased physical activity and improved vascular compliance as reflected by reduced PWV and attenuated collagen deposition. Aorta of rmSIRT1-treated mice exhibited increased endothelial nitric oxide (eNOS) activity, while endothelium-dependent contractions of their carotid arteries were significantly decreased, with mesenteric resistance arteries showing preserved hyperpolarization. Ex vivo incubation with reactive oxygen species (ROS) scavenger Tiron and NADPH oxidase inhibitor apocynin revealed that rmSIRT1 leads to preserved vascular function by suppressing NADPH oxidase (NOX)-related ROS synthesis. Chronic rmSIRT1 treatment resulted in reduced expression of both NOX1 and NOX4, in line with a reduction in aortic protein carbonylation and plasma nitrotyrosine levels. CONCLUSIONS: In diabetic conditions, arterial SIRT1 levels are significantly reduced. Chronic rmSIRT1 supplementation improves endothelial function and vascular compliance by enhancing eNOS activity and suppressing NOX-related oxidative stress. Thus, SIRT1 supplementation may represent novel therapeutic strategy to prevent diabetic vascular disease.

Outcomes of inferior vena cava reconstruction using artificial or autologous materials in ex vivo liver resection and autotransplantation.

BACKGROUND: The use of artificial or autologous materials for inferior vena cava (IVC) reconstruction is controversial. This study retrospectively explored the effects of different materials on perioperative outcomes. METHODS: This study included 91 patients who underwent IVC reconstruction during liver autotransplantation between 2014 and 2020. A univariate analysis was performed to select variables affecting postoperative morbidity. The effect of IVC reconstruction materials on perioperative outcomes was tested with a multivariable generalized linear model. The effects on postoperative morbidity and operation time were further tested with the multivariate regression analysis based on the generalized estimating equation. Adjusted models were used in all analyses. RESULTS: A median operation time of 710 (633-790) min, a median blood loss of 2200 (1550-3000) mL, an incidence of 33% (30/91) for major morbidities and a median comprehensive complication index (CCI) of 0.0 (0.0-26.2) were observed, with no IVC reconstruction-related complications postoperatively or in the long term. The IVC reconstruction material had no significant effect on postoperative outcomes, while artificial materials significantly increased inpatient cost (191 ± 35 vs. 164 ± 36 k Yuan, p < 0.001). The multivariate regression revealed a significant shift in outcomes of operation time (p = 0.0368). DISCUSSION: Artificial grafts are recommended for IVC reconstruction if cost is not a factor.

Macrophage NCOR1 protects from atherosclerosis by repressing a pro-atherogenic PPARγ signature.

AIMS: Nuclear receptors and their cofactors regulate key pathophysiological processes in atherosclerosis development. The transcriptional activity of these nuclear receptors is controlled by the nuclear receptor corepressors (NCOR), scaffolding proteins that form the basis of large corepressor complexes. Studies with primary macrophages demonstrated that the deletion of Ncor1 increases the expression of atherosclerotic molecules. However, the role of nuclear receptor corepressors in atherogenesis is unknown. METHODS AND RESULTS: We generated myeloid cell-specific Ncor1 knockout mice and crossbred them with low-density lipoprotein receptor (Ldlr) knockouts to study the role of macrophage NCOR1 in atherosclerosis. We demonstrate that myeloid cell-specific deletion of nuclear receptor corepressor 1 (NCOR1) aggravates atherosclerosis development in mice. Macrophage Ncor1-deficiency leads to increased foam cell formation, enhanced expression of pro-inflammatory cytokines, and atherosclerotic lesions characterized by larger necrotic cores and thinner fibrous caps. The immunometabolic effects of NCOR1 are mediated via suppression of peroxisome proliferator-activated receptor gamma (PPARγ) target genes in mouse and human macrophages, which lead to an enhanced expression of the CD36 scavenger receptor and subsequent increase in oxidized low-density lipoprotein uptake in the absence of NCOR1. Interestingly, in human atherosclerotic plaques, the expression of NCOR1 is reduced whereas the PPARγ signature is increased, and this signature is more pronounced in ruptured compared with non-ruptured carotid plaques. CONCLUSIONS: Our findings show that macrophage NCOR1 blocks the pro-atherogenic functions of PPARγ in atherosclerosis and suggest that stabilizing the NCOR1-PPARγ binding could be a promising strategy to block the pro-atherogenic functions of plaque macrophages and lesion progression in atherosclerotic patients.

Assessment of Vascular Tone Responsiveness using Isolated Mesenteric Arteries with a Focus on Modulation by Perivascular Adipose Tissues.

Altered vascular tone responsiveness to pathophysiological stimuli contributes to the development of a wide range of cardiovascular and metabolic diseases. Endothelial dysfunction represents a major culprit for the reduced vasodilatation and enhanced vasoconstriction of arteries. Adipose (fat) tissues surrounding the arteries play important roles in the regulation of endothelium-dependent relaxation and/or contraction of the vascular smooth muscle cells. The cross-talks between the endothelium and perivascular adipose tissues can be assessed ex vivo using mounted blood vessels by a wire myography system. However, optimal settings should be established for arteries derived from animals of different species, ages, genetic backgrounds and/or pathophysiological conditions.

Seipin Knockout Mice Develop Heart Failure With Preserved Ejection Fraction.

The lean diabetic patients with heart failure with preserved ejection fraction (HFpEF) in Asia suffer from adverse clinical outcomes and poor life quality. The suitable animal models are urgently needed for mechanistic study and therapeutic innovations. Our study reports that lipodystrophic mice with seipin depletion are lean, diabetic, and recapitulate major manifestations of clinical HFpEF, thereby clarifying that lean diabetes per se may produce HFpEF characteristics. We further demonstrate that increased cardiac titin phosphorylation and reactive interstitial fibrosis associated with neutrophil extracellular traps lead to left ventricular stiffness and suggest that both pathways may be potential therapeutic targets in Asian HFpEF patients.

Local enrichment of fatty acid-binding protein 4 in the pericardial cavity of cardiovascular disease patients.

BACKGROUND: The pericardial fluid may be representative of the interstitium of the heart. The aim of this study was to discriminate in cardiovascular disease patients between adipocytokines that are produced locally by the heart and those supplied by the circulation. METHODS: Enzyme-linked immunosorbent assays (ELISA) were used to determine levels of N-terminal pro-brain natriuretic peptide (NT-pBNP), fatty acid-binding protein 4 (FABP4), leptin, lipocalin-2, neutrophil elastase, proteinase-3, high sensitivity C-reactive protein (hsCRP) and adiponectin in venous plasma and pericardial fluid harvested during elective cardio-thoracic surgery (n = 132-152). RESULTS: In pericardial fluid compared to plasma, the levels were significantly smaller (p < 0.001) for leptin, lipocalin-2, neutrophil elastase, proteinase-3, hsCRP and adiponectin. For these biomarkers, the ratio of pericardial fluid-to-plasma level ([PF]/[P], median (interquartile range)) was 0.65 (0.47-1.01), 0.78 (0.56-1.09), 0.23 (0.11-0.60), 0.17 (0.09-0.36), 0.14 (0.08-0.35), and 0.25 (0.15-0.34), respectively. In contrast, pericardial fluid was significantly enriched (p < 0.001) in NT-pBNP ([PF]/[P]: 1.9 (1.06-2.73)) and even more so for FABP4 ([PF]/[P]: 3.90 (1.47-9.77)). Moreover, in pericardial fluid, the adipocytokines interrelated all significantly positive and correlated negative to hsCRP, whereas for NT-pBNP only a significantly positive correlation with adiponectin was found. These interrelations were distinct from those in the plasma, as were the correlations of the pericardial biomarkers with patient characteristics compared to plasma. CONCLUSIONS: In cardiovascular disease patients, the pericardial cavity is a distinct adipocytokine microenvironment in which especially FABP4 is mainly derived from the heart.

Lipocalin-2 derived from adipose tissue mediates aldosterone-induced renal injury.

Lipocalin-2 is not only a sensitive biomarker, but it also contributes to the pathogenesis of renal injuries. The present study demonstrates that adipose tissue-derived lipocalin-2 plays a critical role in causing both chronic and acute renal injuries. Four-week treatment with aldosterone and high salt after uninephrectomy (ANS) significantly increased both circulating and urinary lipocalin-2, and it induced glomerular and tubular injuries in kidneys of WT mice. Despite increased renal expression of lcn2 and urinary excretion of lipocalin-2, mice with selective deletion of lcn2 alleles in adipose tissue (Adipo-LKO) are protected from ANS- or aldosterone-induced renal injuries. By contrast, selective deletion of lcn2 alleles in kidney did not prevent aldosterone- or ANS-induced renal injuries. Transplantation of fat pads from WT donors increased the sensitivity of mice with complete deletion of Lcn2 alleles (LKO) to aldosterone-induced renal injuries. Aldosterone promoted the urinary excretion of a human lipocalin-2 variant, R81E, in turn causing renal injuries in LKO mice. Chronic treatment with R81E triggered significant renal injuries in LKO, resembling those observed in WT mice following ANS challenge. Taken in conjunction, the present results demonstrate that lipocalin-2 derived from adipose tissue causes acute and chronic renal injuries, largely independent of local lcn2 expression in kidney.

Measuring non-polyaminated lipocalin-2 for cardiometabolic risk assessment.

AIMS: Lipocalin-2 is a pro-inflammatory molecule characterized by a highly diversified pattern of expression and structure-functional relationships. In vivo, this molecule exists as multiple variants due to post-translational modifications and/or protein-protein interactions. Lipocalin-2 is modified by polyamination, which enhances the clearance of this protein from the circulation and prevents its excessive accumulation in tissues. On the other hand, animal studies suggest that non-polyaminated lipocalin-2 (npLcn2) plays a causal role in the pathogenesis of obesity-associated medical complications. The present study examined the presence of npLcn2 in samples from healthy volunteers or patients with cardiac abnormalities and evaluated npLcn2 as a biomarker for cardiometabolic risk assessment. METHODS AND RESULTS: Immunoassays were developed to quantify npLcn2 in blood and urine samples collected from 100 volunteers (59 men and 41 women), or venous plasma and pericardial fluid samples obtained from 37 cardiothoracic surgery patients. In healthy volunteers, npLcn2 levels in serum are significantly higher in obese and overweight than in lean subjects. After adjustment for age, gender, smoking, and body mass index (BMI), serum npLcn2 levels are positively correlated with heart rate, circulating triglycerides, high-sensitivity C-reactive protein (hsCRP), and creatinine in plasma. The npLcn2 levels in urine are significantly increased in subjects with metabolic syndrome and positively correlated with BMI, heart rate, circulating triglycerides, and urinary aldosterone. In cardiothoracic surgery patients, the circulating concentrations of npLcn2 are higher (more than two-fold) than those of healthy volunteers and positively correlated with the accumulation of this protein in the pericardial fluid. Heart failure patients exhibit excessive expression and distribution of npLcn2 in mesothelial cells and adipocytes of the parietal pericardium, which are significantly correlated with the elevated plasma levels of npLcn2, total cholesterol, and creatinine. CONCLUSIONS: Quantitative and qualitative evaluation of npLcn2 in human biofluid samples and tissue samples can be applied for risk assessment of healthy individuals and disease management of patients with obesity-related cardiometabolic and renal complications.

Systematic Design of Trypsin Cleavage Site Mutated Exendin4-Cysteine 1, an Orally Bioavailable Glucagon-Like Peptide-1 Receptor Agonist.

Exendin-4 is a strong therapeutic candidate for the treatment of metabolic syndrome. Related receptor agonist drugs have been on the market since 2005. However, technical limitations and the pain caused by subcutaneous injection have severely limited patient compliance. The goal of the study is to investigate a biologically active exendin-4 analog could be administered orally. Using intraperitoneal glucose tolerance tests, we discovered that exendin4-cysteine administered by oral gavage had a distinct hypoglycemic effect in C57BL/6J mice. Using Rosetta Design and Amber, we designed and screened a series of exendin4-cysteine analogs to identify those that retained biological activity while resisting trypsin digestion. Trypsin Cleavage Site Mutated Exendin4-cysteine 1 (TSME-1), an analog whose bioactivity was similar to exendin-4 and was almost completely resistant to trypsin, was screened out. In addition, TSME-1 significantly normalized the blood glucose levels and the availability of TSME-1 was significantly higher than that of exendin-4 and exendin4-cysteine. Collectively orally administered TSME-1, a trypsin-resistant exendin-4 analog obtained by the system, is a strong candidate for future treatments of type 2 diabetes.

Endothelial SIRT1 prevents adverse arterial remodeling by facilitating HERC2-mediated degradation of acetylated LKB1.

Aims-SIRT1 exerts potent activity against cellular senescence and vascular ageing. By decreasing LKB1 protein levels, it promotes the survival and regeneration of endothelial cells. The present study aims to investigate the molecular mechanisms underlying SIRT1-mediated LKB1 degradation for the prevention of vascular ageing.Methods and Results-Co-immunoprecipitation assay demonstrated that SIRT1, via its amino-terminus, binds to the DOC domain of HERC2 [HECT and RLD domain containing E3 ubiquitin protein ligase 2], which then ubiquitinates LKB1 in the nuclear compartment of endothelial cells. Site-directed mutagenesis revealed that acetylation at lysine (K) 64 of LKB1 triggers the formation of SIRT1/HERC2/LKB1 protein complex and subsequent proteasomal degradation. In vitro cellular studies suggested that accumulation of acetylated LKB1 in the nucleus leads to endothelial activation, in turn stimulating the proliferation of vascular smooth muscle cells and the production of extracellular matrix proteins. Chromatin immunoprecipitation quantitative PCR confirmed that acetylated LKB1 interacts with and activates TGFß1 promoter, which is inhibited by SIRT1. Knocking down either SIRT1 or HERC2 results in an increased association of LKB1 with the positive regulatory elements of TGFß1 promoter. In mice without endothelial nitric oxide synthase, selective overexpression of human SIRT1 in endothelium prevents hypertension and age-related adverse arterial remodeling. Lentiviral-mediated knockdown of HERC2 abolishes the beneficial effects of endothelial SIRT1 on both arterial remodeling and arterial blood pressure control.Conclusion-By downregulating acetylated LKB1 protein via HERC2, SIRT1 fine-tunes the crosstalk between endothelial and vascular smooth muscle cells to prevent adverse arterial remodeling and maintain vascular homeostasis.

Lipocalin-2 mediates non-alcoholic steatohepatitis by promoting neutrophil-macrophage crosstalk via the induction of CXCR2.

BACKGROUND & AIMS: Inflammatory cell infiltration in the liver is a hallmark of non-alcoholic steatohepatitis (NASH). However, the pathological events which trigger the infiltration of inflammatory cells to mediate NASH pathogenesis remains poorly understood. This study aims to investigate the role of neutrophil-derived lipocalin 2 (LCN2) in mediating the transition from simple steatosis to NASH. METHODS: Animal models of NASH were induced by high fat high cholesterol (HFHC) diet and methionine- and choline-deficient (MCD) diet in LCN2 knockout mice and wild-type controls. RESULTS: Circulating levels of LCN2 and its hepatic expression were markedly increased in both murine models and human subjects with NASH, and these changes were associated with increased infiltration of neutrophils. In diet-induced NASH models, hepatic injury, necroinflammation and infiltration of neutrophils and macrophages were substantially attenuated by genetic depletion of LCN2. In contrast, chronic infusion of recombinant LCN2 exacerbated diet-induced liver injury, inflammation and macrophage accumulation in a neutrophil-dependent manner. Primary mouse neutrophils lacking LCN2 exhibited a defective migration capacity, which can be reversed by replenishment with recombinant LCN2. Mechanistically, LCN2 induced the expression of the chemokine (C-X-C motif) receptor 2 (CXCR2), thereby leading to activation of ERK1/2 and production of proinflammatory chemokines. LCN2-induced inflammation, infiltration of macrophages and liver injury was abrogated in CXCR2-deficient mice. CONCLUSIONS: These findings demonstrated that LCN2 acts as a central mediator to facilitate the crosstalk between neutrophils and hepatic macrophages via induction of the chemokine receptor CXCR2, thereby exacerbating steatohepatitis. LAY SUMMARY: Lipocalin-2 levels in blood and the liver were markedly increased in both mouse models and human subjects with NASH, and these changes were associated with increased infiltration of neutrophils in the liver. In diet-induced NASH models, hepatic injury, necroinflammation and infiltration of neutrophils and macrophages were substantially attenuated by genetic depletion of lipocalin-2, but was augmented by chronic infusion of recombinant lipocalin-2. Lipocalin-2 induced the expression of the chemokine receptor CXCR2, thereby leading to activation of the mitogen-activated protein (MAP) kinase ERK1/2 and production of proinflammatory chemokines. Lipocalin-2-induced inflammation, infiltration of macrophages and liver injury was abrogated in CXCR2-deficient mice.

A (1)H NMR-Based Metabonomic Investigation of Time-Related Metabolic Trajectories of the Plasma, Urine and Liver Extracts of Hyperlipidemic Hamsters.

The hamster has been previously found to be a suitable model to study the changes associated with diet-induced hyperlipidemia in humans. Traditionally, studies of hyperlipidemia utilize serum- or plasma-based biochemical assays and histopathological evaluation. However, unbiased metabonomic technologies have the potential to identify novel biomarkers of disease. Thus, to obtain a better understanding of the progression of hyperlipidemia and discover potential biomarkers, we have used a proton nuclear magnetic resonance spectroscopy ((1)H-NMR)-based metabonomics approach to study the metabolic changes occurring in the plasma, urine and liver extracts of hamsters fed a high-fat/high-cholesterol diet. Samples were collected at different time points during the progression of hyperlipidemia, and individual proton NMR spectra were visually and statistically assessed using two multivariate analyses (MVA): principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA). Using the commercial software package Chenomx NMR suite, 40 endogenous metabolites in the plasma, 80 in the urine and 60 in the water-soluble fraction of liver extracts were quantified. NMR analysis of all samples showed a time-dependent transition from a physiological to a pathophysiological state during the progression of hyperlipidemia. Analysis of the identified biomarkers of hyperlipidemia suggests that significant perturbations of lipid and amino acid metabolism, as well as inflammation, oxidative stress and changes in gut microbiota metabolites, occurred following cholesterol overloading. The results of this study substantially broaden the metabonomic coverage of hyperlipidemia, enhance our understanding of the mechanism of hyperlipidemia and demonstrate the effectiveness of the NMR-based metabonomics approach to study a complex disease.

[A 1H NMR based metabonomics approach to progression of coronary atherosclerosis in a hamster model].

To obtain a better understanding of the progression of atherosclerosis and identify potential biomarkers, proton nuclear magnetic resonance spectroscopy (1H NMR)-based metabonomics was used to study the metabolic changes in the plasma of hamster fed with a high-fat/cholesterol diet. Plasma samples were collected at different time points during the progression of atherosclerosis and individual proton NMR spectra were visually and statistically assessed using multivariate analyses. NMR results for all samples showed a time-dependent development from physiological to pathophysiological status during atherosclerosis. Analysis of the identified biomarkers of atherosclerosis suggests that lipid and amino acid metabolisms are significantly disturbed, together with inflammation, oxidative stress, following cholesterol overloading. The results enriched our understanding of the mechanism of atherosclerosis and demonstrated the effectiveness of the NMR-based metabonomics approach to study such a complex disease.

Inhibition of PTEN expression and activity by angiotensin II induces proliferation and migration of vascular smooth muscle cells.

PTEN (phosphatase and tensin homolog deleted on chromosome 10) is a tumor suppressor and has been suggested recently to be involved in the regulation of cardiovascular diseases. The molecular mechanisms of this regulation are however poorly understood. This study shows that down regulation of PTEN expression and activity by angiotensin II (Ang II) increased proliferation and migration of vascular smooth muscle cells (VSMCs). The presence of Ang II induced rapid PTEN phosphorylation and oxidation in accordance with increased AKT and FAK phosphorylation. The Ang II-mediated VSMC proliferation and migration was inhibited when cellular PTEN expression was increased by AT1 inhibitor losartan, PPARγ agonist rosiglitazone, NF-κB inhibitor BAY 11-7082. Over expression of PTEN in VSMCs by adenovirus transduction also resulted in inhibition of cell proliferation and migration in response to Ang II. These results suggest that PTEN down-regulation is involved in proliferation and migration of VSMCs induced by Ang II. This provides insight into the molecular regulation of PTEN in vascular smooth muscle cells and suggests that targeting the action of PTEN may represent an effective therapeutic approach for the treatment of cardiovascular diseases.

A simple and sensitive method for lipoprotein and lipids profiles analysis of individual micro-liter scale serum samples.

A simple and sensitive method to determine lipoprotein and lipids profiles in micro-liter scale individual serum sample is not presently available. Traditional lipoprotein separation techniques either by ultra-centrifugation or by liquid chromatography methods have their disadvantages in both lipoprotein separation and lipids component quantification. In this study we used small volume needing size-exclusion fast protein liquid chromatography to separate different lipoprotein subclasses in 50µL serum. And lipids contents, such as cholesterol, cholesterol ester and triacylglycerol, were measured by using two different fluorescence-based lipid detection methods. With this method, very low density lipoprotein, low density lipoprotein and high density lipoprotein could be easily separated, and follow-up lipid detection was completed by simple kinds of reactions. Serum lipoprotein and lipids profiling from C57BL/6 mice (n=5) and human (n=5) were analyzed. The elution profiles of five individuals were highly reproducible, and there were lipoprotein and lipids distribution variations between C57BL/6 mice and human beings. In conclusion, this method which combined small volume needing size-exclusion fast protein liquid chromatography and fluorescence-based lipids measurement, provided a simple, efficient, integrity and reproducible procedure for determining serum lipoprotein and lipids profiles in micro-liter scale levels. It becomes possible that determination of lipoprotein profiles and gaining information of lipids in different lipoproteins can be accomplished simultaneously.