Oxidized low-density lipoprotein receptor 1:a novel potential therapeutic target for intracerebral hemorrhage

Oxidized low-density lipoprotein receptor 1(OLR1)is upregulated in neurons and participates in hypertension-induced neuronal apoptosis.OLR1 deletion exerts protective effects on cerebral damage induced by hypertensive-induced stroke.Therefore,OLR1 is likely involved in the progress of intracerebral hemorrhage.In this study,we examined the potential role of OLR1 in intracerebral hemorrhage using a rat model.OLR1 small interfering RNA(10μL;50 pmol/μL)was injected into the right basal ganglia to knock down OLR1.Twenty-four hours later,0.5 U collagenase type VII was injected to induce intracerebral hemorrhage.We found that knockdown of OLR1 attenuated neurological behavior impairment in rats with intracerebral hemorrhage and reduced hematoma,neuron loss,inflammatory reaction,and oxidative stress in rat brain tissue.We also found that silencing of OLR1 suppressed ferroptosis induced by intracerebral hemorrhage and the p38 signaling pathway.Therefore,silencing OLR1 exhibits protective effects against secondary injury of intracerebral hemorrhage.These findings suggest that OLR1 may be a novel potential therapeutic target for intracerebral hemorrhage.

C1q/TNF-related protein 5 promotes atherogenesis by enhancing transcytosis and oxidative modification of low-density lipoprotein through increasing 12/15-lipoxygenase

Objective Increased transcytosis of low-density lipoprotein (LDL)across the endothelium and oxidation of LDL deposited within the subendothelial space are crucial early events in atherogenesis. C1q/TNF-related protein (CTRP) 5 is a novel secreted glycoprotein and its biological functions are largely undefined.

Sleeve gastrectomy prevents lipoprotein receptor-1 expression in aortas of obese rats

AIM: To investigate the effects of sleeve gastrectomy on adipose tissue infiltration and lectin-like oxidized low density lipoprotein receptor-1 (LOX-1) expression in rat aortas. METHODS: Twenty-four rats were randomized into three groups: normal chow (control), high fat diet (HD) and high fat diet with sleeve gastrectomy (SG). After surgery, the HD and SG groups were fed a high fat diet. Animals were sacrificed and plasma high density lipoprotein (HDL) and low density lipoprotein (LDL) levels were determined. LOX-1 protein and LOX-1 mRNA expression was also measured. Aortas were stained with Nile red to visualize adipose tissue. RESULT: Body weights were higher in the HD group compared to the other groups. HDL levels in control,HD, and SG groups were 32.9 ± 6.2 mg/dL, 43.4 ± 4.0 mg/dL and 37.5 ± 4.3 mg/dL, respectively. LDL levels in control, HD, and SG groups were 31.8 ± 4.5 mg/dL, 53.3 ± 5.1 mg/dL and 40.5 ± 3.7 mg/dL, respectively. LOX-1 protein and LOX-1 mRNA expression was greater in the HD group versus the other groups. Staining for adipose tissue in aortas was greater in the HD group in comparison to the other groups. Thus, a high fat diet elevates LOX-1 protein and mRNA expression in aorta. CONCLUSION: Sleeve gastrectomy decreases plasma LDL levels, and downregulates LOX-1 protein and mRNA expression.

Roles of low?density lipoproteinreceptor?related protein 1 in tumors

Low-density lipoprotein receptor-related protein 1(LRP1,also known as CD91),a multifunctional endocytic and cell signaling receptor,is widely expressed on the surface of multiple cell types such as hepatocytes,fibroblasts,neurons,astrocytes,macrophages,smooth muscle cells,and malignant cells.Emerging in vitro and in vivo evidence demonstrates that LRP1 is critically involved in many processes that drive tumorigenesis and tumor progression.For example,LRP1 not only promotes tumor cell migration and invasion by regulating matrix metalloproteinase(MMP)-2and MMP-9 expression and functions but also inhibits cell apoptosis by regulating the insulin receptor,the serine/threonine protein kinase signaling pathway,and the expression of Caspase-3.LRPI-mediated phosphorylation of the extracellular signal-regulated kinase pathway and c-jun N-terminal kinase are also involved in tumor cell proliferation and invasion.In addition,LRP1 has been shown to be down-regulated by microRNA-205 and methylation of LRP1CpG islands.Furthermore,a novel fusion gene,LRP1-SNRNP25,promotes osteosarcoma cell invasion and migration.Only by understanding the mechanisms of these effects can we develop novel diagnostic and therapeutic strategies for cancers mediated by LRP1.

Editorial on hemoglobin A1c, blood pressure, and lowdensity lipoprotein cholesterol goals in diabetics

The American Diabetes Association (ADA) 2013 guidelines state that a reasonable hemoglobin A1c goal for many nonpregnant adults with diabetes is less than 7.0% a hemoglobin A1c level of less than 6.5% may be considered in adults with short duration of diabetes, long life expectancy, and no significant cardiovascular disease if this can be achieved without significant hypoglycemia or other adverse effects of treatment. A hemoglobin A1c level less than 8.0% may be appropriate for patients with a history of severe hypoglycemia, limited life expectancy, advanced macrovascular and microvascular complications, extensive comorbidities, and long-standing diabetes in whom the hemoglobin A1c goal is difficult to attain despite multiple glucoselowering drugs including insulin. The ADA 2013 guidelines recommend that the systolic blood pressure in most diabetics with hypertension should be reduced to less than 140 mmHg. These guidelines also recommend use of an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker in the treatment of hypertension in diabetics unless they are pregnant. Diabetics at high risk for cardiovascular events should have theirserum low-density lipoprotein (LDL) cholesterol lowered to less than 70 mg/dL with statins. Lower-risk diabetics should have their serum LDL cholesterol reduced to less than 100 mg/dL. Combination therapy of a statin with either a fibrate or niacin has not been shown to provide additional cardiovascular benefit above statin therapy alone and is not recommended. Hypertriglyceridemia should be treated with dietary and lifestyle changes. Severe hypertriglyceridemia should be treated with drug therapy to reduce the risk of acute pancreatitis.

高血压病患者血清sLOX-1与hs-CRP的相关性研究

目的:探讨高血压病患者的血清可溶性凝集素样氧化型低密度脂蛋白受体-1(sLOX-1)与超敏C反应蛋白(hs-CRP)水平的相关性及其临床意义。方法:用酶联免疫吸附测定法测定139例高血压病组(包括低危组46例,中危组46例,高危组47例)及48例对照组的sLOX-1及hs-CRP浓度。结果:随着病情(对照组、低危组、中危组、高危组)的加重,血清sLOX-1及hs-CRP浓度有升高的趋势,两者呈正相关(r=0.346,P=0.000)。结论:血清sLOX-1、hs-CRP浓度检测为高血压病患者的诊断和评估提供了新的可能方式。

Low-density lipoprotein receptor-related protein 1 is a CROPs-associated receptor for Clostridioides infection toxin B

As the leading cause of worldwide hospital-acquired infection,Clostridioides difficile(C.difficile)infection has caused heavy economic and hospitalized burden,while its pathogenesis is not fully understood.Toxin B(Tcd B)is one of the major virulent factors of C.difficile.Recently,CSPG4 and FZD2 were reported to be the receptors that mediate Tcd B cellular entry.However,genetic ablation of genes encoding these receptors failed to completely block Tcd B entry,implicating the existence of alternative receptor(s)for this toxin.Here,by employing the CRISPR-Cas9 screen in CSPG4-deficient He La cells,we identified LDL receptor-related protein-1(LRP1)as a novel receptor for Tcd B.Knockout of LRP1 in both CSPG4-deficient He La cells and colonic epithelium Caco2 cells conferred cells with increased Tcd B resistance,while LRP1 overexpression sensitized cells to Tcd B at a low concentration.Co-immunoprecipitation assay showed that LRP1 interacts with full-length Tcd B.Moreover,CROPs domain,which is dispensable for Tcd B’s interaction with CSPG4 and FZD2,is sufficient for binding to LRP1.As such,our study provided evidence for a novel mechanism of Tcd B entry and suggested potential therapeutic targets for treating C.difficile infection.

Effect of serum concentration on adhesion of monocytic THP-1 cells onto cultured EC monolayer and EC-SMC co-culture

Background:The adhesion of monocytes to the endothelium following accumulation of low-density lipoprotein (LDL) in subendothelial spaces is an important step in the development of intimal hyperplasia in arterially implanted vein grafts and atherosclerosis in both animals and humans. However, it is not well known how serum factors affect the adhesion of monocytes. Methods: We have studied the effect of fetal calf serum (FCS), which we considered a source of LDL, on the adhesion of monocytes to endothelial cells (ECs) by using human monocytic THP-1 cells and both a monolayer of cultured bovine aortic endothelial cells (EC monoculture) and a co-culture with bovine aortic smooth muscle cells (EC-SMC co-culture). Results: It was found that the addition of FCS to the medium greatly affected the adhesion of THP-1 cells, and the higher the concentration of FCS in the medium, the greater the adhesion of THP-1 cells to endothelial cells. Adhesion of THP-1 cells to an EC-SMC co-culture was approximately twofold greater than that to an EC monoculture, and after adhering to endothelial cells, many THP-1 cells trans-migrated into the layer of smooth muscle cells. Conclusion: The results suggest that the elevation of the LDL (cholesterol) level in blood provides a favorable condition for the development of intimal hyperplasia and atherosclerosis by promoting the adhesion of monocytes to the endothelium and their subsequent migration into subendothelial spaces.

EFFECTS OF RAPAMYCIN ON INTRACELLULAR CHOLESTEROL HOMEOSTASIS OF GLOMERULAR MESANGIAL CELL IN THE PRESENCE OF INTERLEUKIN-1β

Objective To investigate the effects of rapamycin on cholesterol homeostasis of glomerular mesangial cells and the underlying mechanisms. Methods Intracellular cholesterol accumulation was measured by Oil Red O staining and high performance liquid chromatography. The effects of rapamycin on interleukin-1β（1L-1β）-induced mRNA and protein changes of low-density lipoprotein receptor （LDLR） and ATP-binding cassette transporter Al （ABCAl） were assayed by quantitative real-time PCR and Western blot. Transient expressions of 3 types of mammalian target of rapamycin （mTOR）, including mTOR-WT （wild type）, mTOR-RR （rapamycin resistant, with kinase activity）, and mTOR-RR-KD （rapamycin resistant, without kinase activity）, were obtained by plasmid transfection. Results Rapamycin had no significant influence on intracellular cholesterol concentration trader normal condition, but it significantly decreased the intracellular cholesterol concentration in the presence of IL-1β. Rapamycin dose-dependently suppressed the increased expression of LDLR induced by IL-1β and up-regulated the suppressed expression of ABCAl caused by IL-1β Transient expression of 3 types of mTOR all reduced ABCAl mRNA expression significantly, which all could be overroded by rapamycin. Conclusions Rapamycin may contribute to the maintaining of glomerular mesangial cell intracellular cholesterol homeostasis under inflammatory state by both reducing cholesterol uptake and increasing cholesterol effiux. And the effect may be not completely mediiated by mTOR.

Lack of Association of Common Polymorphism of LRP1 Gene with Myocardial Infarction in a Chinese Han Population

This study examined the association of a common polymorphic allele（25G） of the low-density lipoprotein receptor-related protein1（LRP1） gene with myocardial infarction（MI）.The genotypes of LRP1 25CG（rs35282763） were determined in 347 MI patients and 347 age-and sex-frequency-matched controls from an unrelated Chinese Han population.Factor Ⅷ（FⅧ） levels were measured in the MI patients and controls by chromogenic assay and enzyme-linked immunosor-bent assay（ELISA）.The results showed that LRP1 25CG（rs35282763） genotype distribution did not differ significantly between patients（n=206 for 25CC,n=122 for 25CG） and controls（n=191 for 25CC,n=126 for 25CG;P0.05）.The 25G allele was not associated with a reduced risk of MI（P0.05）.Further stratifications for age,sex,and other cardiovascular risk factors did not affect the negative findings.It was concluded that the presence of the G allele at the 25CG（rs35282763） polymorphism of the LRP1 is not associated with a reduced risk of MI,and genotyping for LRP1 25CG（rs35282763） polymor-phism is not useful in assessing the individual risk of MI.

Liver as a new target organ in Alzheimer's disease:insight from cholesterol metabolism and its role in amyloid-beta clearance

Alzheimer's disease,the primary cause of dementia,is characterized by neuropathologies,such as amyloid plaques,synaptic and neuronal degeneration,and neurofibrillary tangles.Although amyloid plaques are the primary characteristic of Alzheimer's disease in the central nervous system and peripheral organs,targeting amyloid-beta clearance in the central nervous system has shown limited clinical efficacy in Alzheimer's disease treatment.Metabolic abnormalities are commonly observed in patients with Alzheimer's disease.The liver is the primary peripheral organ involved in amyloid-beta metabolism,playing a crucial role in the pathophysiology of Alzheimer's disease.Notably,impaired cholesterol metabolism in the liver may exacerbate the development of Alzheimer's disease.In this review,we explore the underlying causes of Alzheimer's disease and elucidate the role of the liver in amyloid-beta clearance and cholesterol metabolism.Furthermore,we propose that restoring normal cholesterol metabolism in the liver could represent a promising therapeutic strategy for addressing Alzheimer's disease.

Association between moderately oxidized low-density lipoprotein and high-density lipoprotein particle subclass distribution in hemodialyzed and post-renal transplant patients

Disturbances in the metabolism of lipoprotein profiles and oxidative stress in hemodialyzed （HD） and post-renal transplant （Tx） patients are proatherogenic, but elevated concentrations of plasma high-density lipoprotein （HDL） reduce the risk of cardiovascular disease. We investigated the concentrations of lipid, lipoprotein, HDL particle, oxidized low-density lipoprotein （ox-LDL） and anti-ox-LDL, and paraoxonase-1 （PON-1） activity in HD （n=33） and Tx （n=71） patients who were non-smokers without active inflammatory disease, liver disease, diabetes, or malignancy. HD patients had moderate hypertriglyceridemia, normocholesterolemia, low HDL-C, apolipoprotein A-I （apoA-I） and HDL particle concentrations as well as PON-1 activity, and increased ox-LDL and anti-ox-LDL levels. Tx patients had hypertriglyceridemia, hypercholesterolemia, moderately decreased HDL-C and HDL particle concentrations and PON-1 activity, and moderately increased ox-LDL and anti-ox-LDL levels as compared to the reference, but ox-LDL and anti-ox-LDL levels and PON-1 activity were more disturbed in HD patients. However, in both patient groups, lipid and lipoprotein ratios （total cholesterol （TC）/HDL-C, LDL-C/HDL-C, triglyceride （TG）/HDL-C, HDL-C/non-HDL-C, apoA-I/apoB, HDL-C/apoA-I, TG/HDL） were atherogenic. The Spearman＇s rank coefficient test showed that the concentration of ox-LDL correlated positively with HDL particle level （R=0.363, P=0.004）, and negatively with TC （R=-0.306, P=0.012）, LDL-C （R=-0.283, P=0.020）, and non-HDL-C （R=-0.263, P=0.030） levels in Tx patients. Multiple stepwise forward regression analysis in Tx patients demonstrated that ox-LDL concentration, as an independent variable, was associated significantly positively with HDL particle level. The results indicated that ox-LDL and de- creased PON-1 activity in Tx patients may give rise to more mildly-oxidized HDLs, which are less stable, easily undergo metabolic remodeling, generate a greater number of smaller pre-13-HDL particles, and thus accelerate reverse cholesterol transport, which may be beneficial for Tx patients. Further studies are necessary to confirm this.

LOX-1 Regulation in Anti-atherosclerosis of Active Compounds of Herbal Medicine:Current Knowledge and the New Insight

Lectin-like oxidized low-density lipoprotein receptor-1(LOX-1)have recently been identified to be closely related to the occurrence and development of atherosclerosis(AS).A growing body of evidence has suggested Chinese medicine takes unique advantages in preventing and treating As.In this review,the related research progress of AS and LOX-1 has been summarized.And the anti-As effects of 10 active components of herbal medicine through LOX-1 regulation have been further reviewed.As a potential biomarker and target for intervention in AS,LOX-1 targeted therapy might provide a promising and novel approach to atherosclerotic prevention andtreatment.

Hepatitis C eradication with sofosbuvir leads to significant metabolic changes

AIMTo assess the effect of sofosbuvir (SOF) based regimens on glycemic and lipid control. METHODSThis is a retrospective analysis of hepatitis C virus (HCV)-infected patients treated and cured with a SOF regimen [SOF/ribavirin/interferon, SOF/simeprevir, or SOF/ledipasvir (LDV) ± ribavirin] from January 2014 to March 2015. Patients with hemoglobin A1C (HbA1C) and lipid panels within six months before and six months after therapy were identified and included in our study. Due to the known hemolytic effect of ribavirin, HbA1C was obtained a minimum of three months post-treatment for the patients treated with a ribavirin regimen. Medical history, demographics, HCV genotype, pre-therapy RNA, and liver biopsies were included in our analysis. The patients who started a new medication or had an adjustment of baseline medical management for hyperlipidemia or diabetes mellitus (DM) were excluded from our analysis. RESULTSTwo hundred and thirty-four patients were reviewed, of which 60 patients met inclusion criteria. Sixty-three point three percent were male, 26.7% were Caucasian, 41.7% were African American and 91.7% were infected with hepatitis C genotype 1. Mean age was 60.6 ± 6.7 years. Thirty-nine patients had HbA1C checked before and after treatment, of which 22 had the diagnosis of DM type 2. HbA1C significantly decreased with treatment of HCV (pretreatment 6.66% ± 0.95% vs post-treatment 6.14% ± 0.65%, P vs 0.71% ± 0.83%, P = 0.070). Fifty-two patients had pre- and post-treatment lipid panels; there was a significant increase in low-density lipoprotein (LDL) and total cholesterol (TC) after treatment (LDL: 99.5 ± 28.9 mg/dL vs 128.3 ± 34.9 mg/dL, P vs 199.7 ± 40.0 mg/dL, P P = 0.684). CONCLUSIONEradication of HCV with a SOF regimen resulted in a significant drop in HbA1C and an increase in LDL and TC post therapy.

Comparison of three fluorescence labeling and tracking methods of endothelial progenitor cells in laser-injured retina

AIM： To compare three kinds of fluorescent probes for in vitro labeling and in vivo tracking of endothelial progenitor cells（EPCs） in a mouse model of laser-induced retinal injury.METHODS： EPCs were isolated from human umbilical cord blood mononuclear cells and labeled with three different fluorescent probes： 5-（and-6）-carboxyfluorescein diacetate succinimidyl ester（CFSE）, 1,1′-dilinoleyl-3,3,3′,3′-tetramethylindo-carbocyanine perchlorate linked acetylated low-density lipoprotein（Di I-Ac LDL）, and green fluorescent protein（GFP）. The fluorescent intensity of EPCs was examined by confocal microscopy. Survival rate of labeled EPCs was calculated with trypan blue staining, and their adhesive capability was assessed. A mouse model of retinal injury was induced by laser, and EPCs were injected into the vitreous cavity. Frozen section and fluorescein angiography on flat-mounted retinal samples was employed to track the labeled EPCs in vivo.RESULTS： EPCs labeled with CFSE and Di I-Ac LDL exhibited an intense green and red fluorescence at the beginning; the fluorescence intensity decreased gradually to 20.23% and 49.99% respectively, after 28 d. On the contrary, the florescent intensity of GFP-labeled EPCs increased in a time-dependent manner. All labeled EPCs showed normal morphology and no significant change in survival and adhesive capability. In the mouse model, transplantation of EPCs showed a protective effect against retinal injury. EPCs labeled with CFSE and Di I-Ac LDL were successfully tracked in mice during the development of retinal injury and repair; however, GFP-labeled EPCs were not detected in the laser-injured mouse retina.CONCLUSION： The three fluorescent markers used in this study have their own set of advantages and disadvantages. CFSE and Di I-Ac LDL are suitable for short-term EPClabeling, while GFP should be used for long-term labeling. The choice of fluorescent markers should be guided by the purpose of the study.

Prediction of Metabolic Disorders Using NMR-Based Metabolomics:The Shanghai Changfeng Study

A metabolically healthy status,whether obese or not,is a transient stage with the potential to develop into metabolic disor-ders during the course of life.We investigated the incidence of metabolic disorders in 1078 metabolically healthy Chinese adults from the Shanghai Changfeng Study and looked for metabolites that discriminated the participants who would develop metabolic disorders in the future.Participants were divided into metabolically healthy overweight/obesity(MHO)and meta-bolically healthy normal weight(MHNW)groups according to their body mass index(BMI)and metabolic status.Their serum metabolomic profile was measured using a ^(1)H nuclear magnetic resonance spectrometer(^(1)H-NMR).The prevalence of diabetes,hypertriglyceridemia,hypercholesterolemia and metabolic syndrome was similar between the MHNW and MHO participants at baseline.After a median of 4.2 years of follow-up,more MHO participants became metabolically unhealthy than MHNW participants.However,a subgroup of MHO participants who remained metabolically healthy(MHO→MHO)had a similar prevalence of metabolic disorders as the MHNW participants at the follow-up examination,despite a signifi-cant reduction in their serum concentrations of high-density lipoprotein(HDL)and an elevation in valine,leucine,alanine and tyrosine.Further correlation analysis indicated that serum intermediate-density lipoprotein(IDL)and very low-density lipoprotein cholesterol(VLDL-CH)might be involved in the transition from metabolically healthy to unhealthy status and could be valuable to identify the MHNW and MHO with increased metabolic risks.