Myocardial infarction drives trained immunity of monocytes, accelerating atherosclerosis.

BACKGROUND AND AIMS: Survivors of acute coronary syndromes face an elevated risk of recurrent atherosclerosis-related vascular events despite advanced medical treatments. The underlying causes remain unclear. This study aims to investigate whether myocardial infarction (MI)-induced trained immunity in monocytes could sustain proatherogenic traits and expedite atherosclerosis. METHODS: Apolipoprotein-E deficient (ApoE-/-) mice and adoptive bone marrow transfer chimeric mice underwent MI or myocardial ischaemia-reperfusion (IR). A subsequent 12-week high-fat diet (HFD) regimen was implemented to elucidate the mechanism behind monocyte trained immunity. In addition, classical monocytes were analysed by flow cytometry in the blood of enrolled patients. RESULTS: In MI and IR mice, blood monocytes and bone marrow-derived macrophages exhibited elevated spleen tyrosine kinase (SYK), lysine methyltransferase 5A (KMT5A), and CCHC-type zinc finger nucleic acid-binding protein (CNBP) expression upon exposure to a HFD or oxidized LDL (oxLDL) stimulation. MI-induced trained immunity was transmissible by transplantation of bone marrow to accelerate atherosclerosis in naive recipients. KMT5A specifically recruited monomethylation of Lys20 of histone H4 (H4K20me) to the gene body of SYK and synergistically transactivated SYK with CNBP. In vivo small interfering RNA (siRNA) inhibition of KMT5A or CNBP potentially slowed post-MI atherosclerosis. Sympathetic denervation with 6-hydroxydopamine reduced atherosclerosis and inflammation after MI. Classical monocytes from ST-elevation MI (STEMI) patients with advanced coronary lesions expressed higher SYK and KMT5A gene levels. CONCLUSIONS: The findings underscore the crucial role of monocyte trained immunity in accelerated atherosclerosis after MI, implying that SYK in blood classical monocytes may serve as a predictive factor for the progression of atherosclerosis in STEMI patients.

[Mechanism of pathogenesis of Jingfang Mixture in intervention of chronic spontaneous urticaria based on serum metabolomics].

This study aims to clarify the effect of Jingfang Mixture on the treatment of chronic urticarial and its mechanism, and investigate the regulatory effect of chronic urticaria on the metabolic disorder of endogenous metabolites in the blood. The mice were randomly divided into normal group, model group, and Jingfang Mixture group, and modeling and administration continued for 21 d. The changes in endogenous small molecules in rat serum were determined by ultra-high performance liquid chromatography-electrospray ionization-Q Exactive-Orbitrap-mass spectrometry(UHPLC-ESI-QE-Orbitrap-MS) metabolomics technology. The change trend of endogenous metabolites in rat serum was analyzed to find potential biomarkers. The results showed that Jingfang Mixture regulate 16 biomarkers, mainly including taurine, glutamate, succinic acid, docosahexaenoic acid, and arachidonic acid. Metabolic pathway analysis was carried out by MetaboAnalyst, and P<0.01 was taken as the potential key metabolic pathway. Ten metabolic pathways were closely related to the treatment of chronic urticarial by Jingfang Mixture, mainly involved in the glutamate metabolism, taurine and hypotaurine metabolism, arginine and proline metabolism, arachidonic acid metabolism, tricarboxylic acid cycle, unsaturated fatty acid biosynthesis, glutathione metabolism, phenylalanine metabolism, alanine, aspartic acid, and glutamate metabolism, and butyric acid metabolism. Glutamate metabolism and butyric acid metabolism involved more metabolic pathways than others. Therefore, it was speculated that Jingfang Mixture had a balanced regulating effect on the related metabolic pathways which caused the serum disorder in the rats with urticaria, and tended to regulate the metabolic differential to the normal level in the rats with urticaria. This paper provides references for studying the mechanism of Jingfang Mixture from the perspective of endogenous metabolites and metabolic pathways in vivo. At the same time, the endogenous substances explored in this paper can be used as important biomarkers for the prevention of urticaria.

[Proteomic study of Jingfang Mixture on urticaria based on label-free quantitative proteomics technology].

This study aims to explore the effect of Jingfang Mixture on the protein expression of urticaria in mice and explain the mechanism of Jingfang Mixture in the treatment of urticaria. Twenty-seven male Kunming mice were randomly divided into a normal group, a model group and a Jingfang Mixture group according to body weight. Except for the normal group, mice in the model group and the Jingfang Mixture group were injected with the mixture of ovalbumin and Al(OH)_3 gel for the first immunization, and the second immunization was performed on the 10 th day to induce the urticaria model. Mice in the Jingfang Mixture group started to be administered on the 6 th day after the initial immunization, and was administered continuously for 21 days. The normal group and the model group were replaced with the same amount of purified water. Twenty-four hours after the last administration, an appropriate amount of skin was taken, and label-free quantitative proteomics technology was used to detect the differences in protein expression in skin tissue. The signaling pathways involved in the differential proteins was further analyzed. The results of proteomics indicated that seventy-six proteins were involved in the intervention of Jingfang Mixture on mice with urticaria, and the differential proteins were mainly enriched in biological process(BP), molecular function(MF), and cellular component(CC). Kyoto Encyclopedia of Genes and Genomes(KEGG) analysis showed that the signaling pathways regulated by Jingfang Mixture mainly involved carbon metabolism, metabolic pathways, glucagon signaling pathway, glycolysis/gluconeogenesis, pentose phosphate pathway, hypoxia inducible factor-1(HIF-1) signaling pathway, purine metabolism, adherens junction, calcium signaling pathway, leukocyte transendothelial migration, and inflammatory mediator regulation of transient receptor potential(TRP) channels, which were involved in skin tissue energy metabolism and immune regulation. The findings of this study showed that the protective effect of Jingfang Mixture on mice with urticaria was closely related to the regulation of immune disorders, and the regulatory effect on immune system may be achieved through the regulation of energy metabolism by Jingfang Mixture.

[Therapeutic effect and mechanism of Shouhui Tongbian Capsules on slow transit constipation model mice].

Shouhui Tongbian Capsules was used to explore the therapeutic effect and potential mechanism on slow transit constipation model mice induced by loperamide hydrochloride. In the experiment, loperamide hydrochloride-induced ICR mice were used as the model of slow transit constipation. Fifty ICR mice were divided into the blank group, model group and high, medium and low dose groups of Shouhui Tongbian Capsules extract(100, 200 and 400 mg·kg~(-1)). The model group and the administration groups were then modeled using loperamide hydrochloride intragastrically to obtain slow transit constipation. After successful modeling, high, medium and low doses of drugs were given to each drug group by intragastric administration. After 14 days of administration, the first defecation time, 6 h defecation grain number, 6 h defecation wet weight and dry weight, black feces discharged within 6 h and the fecal water content were measured. Intestinal tissues were taken for c-Kit and SCF immunohistochemical sections to detect the expression of c-Kit and SCF in the blank group, model group and high, medium and low dose groups of the medicinal extract of Shouhui Tongbian Capsules. The tissue changes in the intestinal wall of mice were detected by HE staining. At the same time, partial intestinal tissues were taken to test the activity of ATP synthase and isocitrate dehydrogenase in intestinal tissues of mice. RESULTS:: showed that Shouhui Tongbian Capsules effectively improved the symptoms of slow transit constipation in ICR mice and promoted intestinal movement. Shouhui Tongbian Capsules obviously shortened the time of discharging black stool for the first time, improved the intestinal propulsion rate, increased the water content and amount of feces, and improved the constipation symptoms. Mechanism study revealed that Shouhui Tongbian Capsules increased ATP synthase activity and mitochondrial isocitrate dehydrogenase activity in intestinal tissue, and up-regulated c-Kit/SCF signaling pathway to promote interstitial Cajal cells proliferation, intestinal nerve transmission, intestinal motility and transport capacity.

Lowering serum lipids via PCSK9-targeting drugs: current advances and future perspectives.

Proprotein convertase subtilisin/kexin type 9 (PCSK9), also known as neural apoptosis regulated convertase (NARC1), is a key modulator of cholesterol metabolism. PCSK9 increases the serum concentration of low-density lipoprotein cholesterol by escorting low-density lipoprotein receptors (LDLRs) from the membrane of hepatic cells into lysosomes, where the LDLRs are degraded. Owing to the importance of PCSK9 in lipid metabolism, considerable effort has been made over the past decade in developing drugs targeting PCSK9 to lower serum lipid levels. Nevertheless, some problems and challenges remain. In this review we first describes the structure and function of PCSK9 and its gene polymorphisms. We then discuss the various designs of pharmacological targets of PCSK9, including those that block the binding of PCSK9 to hepatic LDLRs (mimetic peptides, adnectins, and monoclonal antibodies), inhibit PCSK9 expression (the clustered regularly interspaced short palindromic repeats/Cas9 platform, small molecules, antisense oligonucleotides, and small interfering RNAs), and interfere with PCSK9 secretion. Finally, this review highlights future challenges in this field, including safety concerns associated with PCSK9 monoclonal antibodies, the limited utility of PCSK9 inhibitors in the central nervous system, and the cost-effectiveness of PCSK9 inhibitors.

A screening strategy for phenotypic detection of carbapenemase in the clinical laboratory.

Nosocomial infections caused by carbapenemase-producing Enterobacteriaceae have emerged as an important challenge worldwide and represent a great limitation for antimicrobial therapy. Detection of carbapenemase in Enterobacteriaceae species also remains challenging. Although the modified Hodge test is recommended, it lacks specificity and is unable to distinguish between carbapenemase types. Here, we demonstrated a screening strategy for the phenotypic detection of carbapenemases among Enterobacteriaceae isolates in the clinical laboratory by using ethylenediaminetetraacetic acid and phenylboronic acid. This strategy displayed an overall 100% sensitivity and 98.6% specificity for carbapenemase detection in Enterobacteriaceae, which was superior to that of the modified Hodge test (98.0% sensitivity and 84.3% specificity), and it also discriminated the carbapenemase phenotypes of KPC-2, VIM-1, and OXA-48.

Inhibitory effect of arctigenin on lymphocyte activation stimulated with PMA/ionomycin.

This study investigated the effect of arctigenin (Arc) on the cell activation, cytokines expression, proliferation, and cell-cycle distribution of mouse T lymphocytes. Mouse lymphocytes were prepared from lymph node and treated with Phorbol-12-myristate-13-acetate (PMA)/Ionimycin (Ion) and/or Arc. CD69, CD25, cytokines, proliferation and cell cycle were assayed by flow cytometry. The results showed that, at concentrations of less than 1.00 micromol x L(-1), Arc expressed non-obvious cell damage to cultured lymphocytes, however, it could significantly down-regulate the expression of CD69 and CD25, as well as TNF-alpha, IFN-gamma, IL-2, IL-4, IL-6 and IL-10 on PMA/Ion stimulated lymphocytes. At the same time, Arc could also inhibit the proliferation of PMA/Ion-activated lymphocytes and exhibited lymphocyte G 0/G1 phase cycle arrest. These results suggest that Arc possesses significant anti-inflammatory effects that may be mediated through the regulation of cell activation, cytokines expression and cell proliferation.

Environmental eustress improves postinfarction cardiac repair via enhancing cardiac macrophage survival.

Macrophages play a vital role in cardiac repair following myocardial infarction (MI). An enriched environment (EE) is involved in the regulation of macrophage-related activities and disease progression; however, whether EE affects the phenotype and function of macrophages to improve postinfarction cardiac repair remains unknown. In this study, we found that EE improved cardiac function, decreased mortality, and ameliorated adverse ventricular remodeling in mice after MI, with these outcomes closely related to the increased survival of Ly6Clow macrophages and their CCR2-MHCIIlow subsets. EE increased the expression of brain-derived neurotrophic factor (BDNF) in the hypothalamus, leading to higher circulating levels of BDNF, which, in turn, regulated the cardiac macrophages. BDNF bound to tropomyosin receptor kinase B to activate downstream ERK1/2 and AKT pathways, promoting macrophage survival. These findings demonstrate that EE optimizes postinfarction cardiac repair and highlights the significance of EE as a previously unidentified strategy for impeding adverse ventricular remodeling.

Serum C-Reactive Protein in Patients with Deficit Schizophrenia and the Relationship with Cognitive Function.

BACKGROUND: Serum levels of C-reactive protein (CRP) were measured in patients with deficit schizophrenia (DS) to confirm the association between CRP level and cognitive performance and to determine whether CRP was a new biological indicator with the potential clinical applications in DS patients. METHODS: Three independent samples [41 DS and 50 non-deficit schizophrenia (NDS) and 30 sex- and age-matched healthy controls (HCs)] were recruited in our study. Serum CRP levels were measured by immunofluorescence. The Positive and Negative Syndrome Scale (PANSS) and alternative forms of the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) were also assessed. And the relationships between serum CRP levels and both PANSS and RBANS scores were finally analyzed. RESULTS: The results of serum CRP level were showed significantly different among the three groups and increased from the HCs to NDS patients to DS patients. There were also significant differences in the cognitive subdomain analyses among the three groups. Serum CRP levels were found positively correlated with total and negative PANSS scores, and showed negatively correlated with overall cognitive test scores in the DS samples. CONCLUSION: Serum C-reactive protein levels and their association with cognitive performance were different between deficit schizophrenia and non-deficit schizophrenia samples, and higher serum CRP level was associated with worse cognitive performance in the DS patients. The results indicated that CRP could be a potential biomarker, and DS could be a distinct subset of schizophrenia.

Application quantitative proteomics approach to identify differentially expressed proteins associated with cardiac protection mediated by cycloastragenol in acute myocardial infarction rats.

Acute myocardial infarction (AMI) is an acute heart disease. Cycloastragenol, as a natural product, inhibits inflammation and protects cardiomyocytes. Cycloastragenol (Y006) modulates inflammation in AMI is not known. To explore the function of Cycloastragenol in AMI, this study investigated the effect of Y006 and its mechanisms both in vitro and in vivo. Y006 influences the concentration of 11 proteins, as shown by a proteomics analysis, immunohistochemistry and western blotting. Among these 11 proteins, Erk1/2, PLCG1, IKBKG, and ZEB1 are related to inflammatory regulation. BAX, COX2, and GSK3ß are involved in modulating cardiomyocyte apoptosis, and RhoA and DSC2 are directly associated with myocardial function. However, the functions of ARHGAP17 and Rit2 in heart are less well established. Additionally, Y006 suppressed TNF-α, IFN-γ and IL-17 production in PBMCs (peripheral blood monocytes) from patients with acute myocardial infarction and enhanced IL-10 and IL-4 expression. Similar results were obtained in a rat model of AMI by flow cytometry detection and ELISA. Our findings indicate that Y006 protects rats from AMI through direct or indirect inhibition of inflammation and cardiomyocyte apoptosis. However, the specific mechanism of Y006's protective function requires further study. Nonetheless, this research revealed a novel aspect for the treatment of myocardial infarction. SIGNIFICANCE: In the present study, we undertook the first proteomic evaluation of Cycloastragenol (Y006) function in acute myocardial infarction (AMI). Y006 significantly improved myocardial function in vivo by regulating multiple molecular expressions. Hypoxia is a direct reason for AMI. And our data support a role of Y006 in gene expression, cell apoptosis under hypoxia. The conclusions of this research assist to explain the potential molecular mechanism in Cycloastragenol treating AMI and supply a new method for ameliorating AMI.

Toxicity Study of 28-Day Subcutaneous Injection of Arctigenin in Beagle Dogs.

Our previous studies have investigated the systematic pharmacokinetic characteristics, biological activities, and toxicity of arctigenin. In this research, the potential toxicities of arctigenin in beagle dogs were investigated via repeated 28-day subcutaneous injections. Beagle dogs were randomly divided into control, vehicle [polyethylene glycol (PEG)], and arctigenin 6, 20, 60 mg/kg treated groups. The whole experimental period lasted 77 days, including adaptive period (35 days), drug exposure period (animals were treated with saline, PEG, or arctigenin for 28 consecutive days), and recovery period (14 days). Arctigenin injection (60 mg/kg) affected the lymphatic hematopoietic, digestive, urinary, and cardiovascular systems, and all the impact on these tissues resulted in death in five dogs (three female and two male dogs); 20 mg/kg arctigenin injection resulted in toxic reactions of the lymphatic hematopoietic and digestive systems; and 6 mg/kg arctigenin and PEG injection did not lead to significant toxic reactions. Meanwhile, there were no sexual differences of drug exposure and accumulation when dogs underwent different dosages. As stated previously, the toxic target organs of arctigenin administration include lymphatic hematopoietic, digestive (liver and gallbladder), urinary (kidney), and cardiovascular (heart) systems, and the no observed adverse effect level (NOAEL) of arctigenin is less than 6 mg/kg.

Essential Oil from Carpesium abrotanoides L. Induces Apoptosis via Activating Mitochondrial Pathway in Hepatocellular Carcinoma Cells.

The effects of essential oil from Carpesium abrotanoides L. (CAEO) on the proliferation and apoptosis of human hepatic cancer cells were investigated in this study. MTT assays indicated that CAEO inhibited the proliferation of HCC cells with the IC50 values ranging from 41.28±3.06 to 130.36±20.79 µg/mL. Moreover, many obviously nuclear morphological changes of apoptotic cells in CAEO-treated HepG2 cells were detected by Hoechst 33258 staining and fluorescence microscopy. Flow cytometry was used to detect cell apoptosis and cell cycle, and noticeable findings showed that CAEO arrested cell-cycle at S and G2/M phases. The decreased Bcl-2/Bax protein ratio and the activation of caspase-3, caspase-9 were also detected by Western blotting. All results suggested that CAEO is a potential agent to fight against liver cancer, and the mitochondria-mediated intrinsic apoptotic pathway could be involved in CAEO-mediated apoptosis of human liver carcinoma cells.

Essential oil from Siegesbeckia pubescens induces apoptosis through the mitochondrial pathway in human HepG2 cells.

Siegesbeckia pubescens (SP) has been used as a traditional medicine for the treatment of and inflammatory diseases. However, the activities of SP against hepatocellular carcinoma and the related mechanisms remain unclear. The present study aimed to examine the effects of the essential oil of SP (SPEO) on the proliferation of hepatocellular carcinoma cells and the possible mechanisms. The growth inhibition of HepG2 cells was analyzed by MTT assay. Hoechst 33258 and fluorescence microscopy were utilized to observe the nuclear morphological changes of apoptotic cells. Flow cytometry was used to detect cell apoptosis and cell cycle. The expressions of the target proteins were detected by Western blotting. The results showed that SPEO obviously inhibited the proliferation of HepG2 cells in a dose-dependent manner. SPEO activated a series of apoptotic proteins in HepG2 cells, increasing expression levels of Bax, caspase-3 and caspase-9, and decreasing the bcl-2 expression level. SPEO displayed promising anti-hepatocellular carcinoma activities in vitro, partly by inducing apoptosis in HepG2 cells through activating the mitochondrial pathway.

Hyperlipidemia-induced apoptosis of hippocampal neurons in apoE(-/-) mice may be associated with increased PCSK9 expression.

Hyperlipidemia is a risk factor for Alzheimer's disease (AD) and other neurodegenerative diseases. Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a lipid regulatory gene involved in cell apoptosis. However, the function and mechanism of PCSK9 in neuronal apoptosis following hyperlipidemia remains to be elucidated. The present study established a hyperlipidemic mouse model by feeding a high­fat diet (HFD) to 6­week­old apoE(­/­) mice. Plasma lipid levels, hippocampal lipid accumulation, hippocampal histology, and hippocampal neuronal apoptosis were all monitored for changes. The expression levels of PCSK9, ß­secretase 1 (BACE1), B­cell lymphoma 2 (Bcl­2), Bcl­2­associated X protein (Bax), and caspase­3 in hippocampal CA3 and CA1 neurons were also measured. Results demonstrated that a HFD increased the lipid accumulation in the CA3 hippocampus and the levels of plasma lipids, including triglycerides, total cholesterol, low­density lipoprotein, and high­density lipoprotein. In addition, CA3 neurons in the HFD group indicated apparent injuries and increased neuronal apoptosis, which are associated with the expression of Bcl­2, Bax, and caspase­3. A HFD also increased the expression levels of PCSK9 and BACE1. BACE1 promotes cleavage of amyloid precursor proteins to generate ß­amyloid peptide (Aß), which induces neuronal apoptosis. Protein levels of Aß are associated with the observation of amyloid plaques in the hippocampus of the HFD group. The results suggest that hyperlipidemia regulates neuronal apoptosis by increasing PCSK9 and BACE1 expression. Overall, the current study may elucidate the role of lipid metabolism disorder in AD pathogenesis.

PCSK9 Promotes oxLDL-Induced PC12 Cell Apoptosis Through the Bcl-2/Bax-Caspase 9/3 Signaling Pathway.

BACKGROUND: Hyperlipidemia is a risk factor for neurodegenerative diseases. Proprotein convertase subtilisin / Kexin type 9 (PCSK9) degrades hepatic low-density lipoprotein receptor (LDLR) to regulate lipid metabolism. It is unclear if PCSK9 plays a role in neurodegenerative diseases. OBJECTIVE: This study was designed to determine whether PCSK9 is crucial between hyperlipidemia and Alzheimer's disease. The interrelationship between PCSK9 and neuronal apoptosis was explored in PC12 cells in response to treatment with oxidized low-density lipoprotein (oxLDL). METHODS: Cultured PC12 cells were serum-starved and incubated with different concentrations of oxLDL for 24 h. Intracytoplasmic lipid droplets were observed by oil red O staining. Morphological assessment of apoptotic cells was performed using Hoechst 33258 staining and flow cytometry analysis. The expression of mRNA and protein was detected by reverse-transcription polymerase chain reaction (RT-PCR) and western blot analyses, respectively. Transfection of small interfering RNA (siRNA) into PC12 cells was conducted using HiperFect Transfection Reagent. Concentrations of Aß40 and Aß42 were detected by enzyme-linked immunosorbent assay (ELISA) kit. RESULTS: Intracellular lipid content, the number of apoptotic cells, and PCSK9 expression were increased in PC12 cells after oxLDL treatment. Transfection with PCSK9 siRNA reduced the oxLDL-induced apoptosis of PC12 cells. We further confirmed the involvement of Bcl-2/Bax-Caspase (9, 3) signaling pathway in the regulation of PC12 cells apoptosis.ß-Secretase 1, another target gene of PCSK9, was downregulated in PC12 cells in response to oxLDL treatment. Aß40 and Aß42 contents were also decreased. CONCLUSION: PCSK9 promotes oxLDL-induced PC12 cell apoptosis through the Bcl-2/Bax-Caspase 9/3 signaling pathway.

Downregulation of leptin inhibits growth and induces apoptosis of lung cancer cells via the Notch and JAK/STAT3 signaling pathways.

Previous studies have documented that leptin is involved in the pathogenesis of many human cancer types by regulation of numerous signal transduction pathways. The aim of this study was to investigate the biological roles of leptin and the mechanisms attributed to its action in non-small cell lung cancer (NSCLC) cell lines. The expression of leptin was measured by quantitative real-time PCR and western blot in seven NSCLC cell lines. Proliferation and apoptosis of NSCLC cells in response to leptin knockdown were determined by MTT assay and flow cytometry, respectively. The effect of leptin knockdown on the Notch and JAK/STAT3 signaling pathways was further examined by western blot. Leptin expression was significantly increased in NSCLC cell lines compared with normal human bronchial epithelial cell HBE. Leptin knockdown inhibited cell proliferation and induced apoptosis in NSCLC cell lines through inactivation of the Notch and JAK/STAT3 signaling pathways. Furthermore, gene silencing of Notch signaling with Notch-1 siRNA or inhibition of JAK/STAT3 signaling by JSI-124, an inhibitor of STAT3, resulted in proliferation inhibition and apoptosis induction in NSCLC A549 cells. Our findings suggested that leptin knockdown could become a new approach for the prevention of lung cancer progression, which is likely to be mediated at least partially by inactivation of the Notch and JAK/STAT3 signaling pathways.

Essential oil from Euphorbia esula inhibits proliferation and induces apoptosis in HepG2 cells via mitochondrial dysfunction

Hepatocellular carcinoma is one of the most prevalent malignancies and a leading cause of cancer-related mortality worldwide. However, the therapies to prevent hepatocellular carcinoma are still limited and the emergence of drug resistance leads to the development of new anti-cancer drugs and combinational chemotherapy regimens. Our study was aimed to explore the anticancer effects of the essential oil extract (EEEO) from Euphorbia esula which has been widely used in traditional Chinese folk medicine and possessed potential cytotoxic effects in several human tumor cells. However, the mechanisms of EEEO-induced anti-proliferation and apoptosis have not been completely elucidated. In this study, EEEO was prepared by hydro-distillation and the main chemical component of EEEO was identified by GC-MS. HepG2 cells were treated with EEEO in vitro and then evaluated with respect to proliferation, apoptosis, and levels of reactive oxygen species (ROS) and apoptotic proteins. Our studies showed that EEEO decreased cell viability, elevated ROS levels, and induced apoptosis of HepG2 cells in a concentration- and time-dependent manner. Furthermore, Bcl-2 was down-regulated, while Bax was up-regulated in HepG2 after EEEO treatment. These results suggest that EEEO induced apoptosis of HepG2 cells and indicate that this apoptosis might be mediated by the mitochondrial pathway.

The dual behavior of PCSK9 in the regulation of apoptosis is crucial in Alzheimer's disease progression (Review).

Neuronal apoptosis is crucial in neurodegenerative diseases. However, a lower apoptotic rate of nerve cells is detected in the brain compared to that in other organs in neurodegenerative patients or in animal models, suggesting that neuronal apoptosis induced by any type of risk factors is intricately regulated. Human and animal studies demonstrated that a high concentration of oxidized LDL (ox-LDL) in the brain, which is associated with hyperlipidemia, is one of the key apoptosis inducers in neurodegenerative diseases. However, the mechanism underlying the ox-LDL-mediated regulation of neuronal apoptosis has not been fully elucidated. Recently, we investigated proprotein convertase subtilisin/kexin type 9 (PCSK9), a striking gene involved in lipid metabolism that exhibits a positive correlation with macrophage and endothelial cell apoptosis induced by ox-LDL. Moreover, PCSK9 may degrade ß-site amyloid precursor protein-cleaving enzyme 1 (BACE1), the key enzyme cleaving amyloid precursor protein (APP) to generate amyloid ß peptide (Aß). Aß is another key apoptosis inducer in neurodegenerative diseases. Our findings indicated that PCSK9 may be upregulated by the high levels of ox-LDL in the brain associated with hyperlipidemia and promote neuronal apoptosis through the NF-κB-B-cell lymphoma 2 (Bcl-2)/Bax-caspase 9-caspase 3 signaling pathways. Moreover, increased PCSK9 levels may inhibit the APP/Aß metabolic pathway and reduce Aß generation by degrading BACE1, thereby decreasing Aß-induced neuronal apoptosis. The dual regulation mechanism of PCSK9 on apoptosis maintains neuronal apoptosis induced by risk factors at low levels.