Cheng Guo

Induction of Nur77 by hyperoside inhibits vascular smooth muscle cell proliferation and neointimal formation.

Nur77 is an orphan nuclear receptor that belongs to the nuclear receptor 4A (NR4A) subfamily, which has been implicated in a variety of biological events, such as cell apoptosis, proliferation, inflammation, and metabolism. Activation of Nur77 has recently been shown to be beneficial for the treatment of cardiovascular and metabolic diseases. The purpose of this study is to identify novel natural Nur77 activators and investigate their roles in preventing vascular diseases. By measuring Nur77 expression using quantitative RT-PCR, we screened active ingredients extracted from Chinese herb medicines with beneficial cardiovascular effects. Hyperoside (quercetin 3-D-galactoside) was identified as one of the potent activators for inducing Nur77 expression and activating its transcriptional activity in vascular smooth muscle cells (VSMCs). We demonstrated that hyperoside, in a time and dose dependent manner, markedly increased the expression of Nur77 in rat VSMCs, with an EC50 of ∼0.83 μM. Mechanistically, we found that hyperoside significantly increased the phosphorylation of ERK1/2 MAP kinase and its downstream target cAMP response element-binding protein (CREB), both of which contributed to the hyperoside-induced Nur77 expression in rat VSMCs. Moreover, through activation of Nur77 receptor, hyperoside markedly inhibited both vascular smooth muscle cell proliferation in vitro and the carotid artery ligation-induced neointimal formation in vivo. These findings demonstrate that hyperoside is a potent natural activator of Nur77 receptor, which can be potentially used for prevention and treatment of occlusive vascular diseases.

Nilotinib reverses ABCB1/P-glycoprotein-mediated multidrug resistance but increases cardiotoxicity of doxorubicin in a MDR xenograft model.

The BCR-Abl tyrosine kinase inhibitor (TKI), nilotinib, was developed to surmount resistance or intolerance to imatinib in patients with Philadelphia-positive chronic myelogenous leukemia. Recent studies have shown that nilotinib induces potent sensitization to anticancer agents by blocking the functions of ABCB1/P-glycoprotein (P-gp) in multidrug resistance (MDR). However, changes in P-gp expression or function affect the cardiac disposition and prolong the presence of both doxorubicin (DOX) and doxorubicinol (DOXol) in cardiac tissue, thus, enhancing the risk of cardiotoxicity. In this study, we used a MDR xenograft model to evaluate the antitumor activity, tissue distribution and cardiotoxicity of DOX when co-administered with nilotinib. This information will provide more insight into the pharmacological role of nilotinib in MDR reversal and the risk of DOX cardiotoxicity. Our results showed that nilotinib significantly enhanced DOX cytotoxicity and increased intracellular rhodamine 123 accumulation in MG63/DOX cells in vitro and strongly enhanced DOX inhibition of growth of P-gp-overexpressing MG63/DOX cell xenografts in nude mice. Additionally, nilotinib significantly increased DOX and DOXol accumulation in serum, heart, liver and tumor tissues. Importantly, nilotinib induced a disproportionate increase in DOXol in cardiac tissue. In the co-administration group, CBR1 and AKR1A1 protein levels were significantly increased in cardiac tissue, with more severe necrosis and vacuole formation. These results indicate that nilotinib reverses P-gp- mediated MDR by blocking the efflux function and potentiates DOX-induced cardiotoxicity. These findings represent a guide for the design of future clinical trials and studies of pharmacokinetic interactions and may be useful in guiding the use of nilotinib in combination therapy of cancer in clinical practice.

Adenovirus-mediated expression of orphan nuclear receptor NR4A2 targeting hepatic stellate cell attenuates liver fibrosis in rats.

Liver fibrosis is a wound-healing response characterized with the accumulation of extracellular matrix (ECM). And hepatic stellate cells (HSCs) are the principal cell source of ECM. NR4A2 (Nurr1) is a member of orphan nuclear receptor NR4A family and acts as transcription factor. It participates in regulating cell differentiation, proliferation and apoptosis. We previously demonstrated that NR4A2 expression in fibrotic liver reduced significantly compared with normal liver and NR4A2 knockout in HSCs promoted ECM production. In the present study we explored the role of NR4A2 on liver fibrosis. Studies in cultured HSCs demonstrated that NR4A2 over-expression suppressed the activation of HSCs, such as ECM production and invasion ability. Moreover cell cycle was arrested, cell apoptosis was promoted and cell signaling pathway was influenced. Adenovirus-mediated delivery of NR4A2 in rats ameliorated significantly dimethylnitrosamine (DMN) induced liver fibrosis. The In vivo experiments produced results consistent with in vitro experiments. Taken together these results demonstrate NR4A2 enhancement attenuates liver fibrosis via suppressing the activation of HSCs and NR4A2 may be an ideal target for anti-fibrotic therapy.

The roles of apolipoprotein E3 and CYP2D6 (rs1065852) gene polymorphisms in the predictability of responses to individualized therapy with donepezil in Han Chinese patients with Alzheimer's disease.

AIMnPolymorphisms in the apolipoprotein E and CYP2D6 genes are widely reported to be related to Alzheimers disease. However, few studies have focused on the relationship between polymorphisms in apolipoprotein E and CYP2D6 (rs1065852) genes and therapeutic responses to donepezil (DNP). This study explored the influence of apolipoprotein E3 and CYP2D6 (rs1065852) gene polymorphisms on therapeutic responses to donepezil in Han Chinese patients with Alzheimers disease.nnnMATERIALS AND METHODSnA total of 85 patients with mild to moderate Alzheimers disease who were treated with 2.5-10mg of DNP per day for at least 3 months were enrolled. Mini-Mental State Examination scores were measured before and after DNP treatment, and the apolipoprotein E3 and CYP2D6 (rs1065852) genotypes of the patients were determined.nnnRESULTSnWe found that ApoE E3 non-carriers responded better to DNP treatment than E3 carriers (p=0.000) and that CYP2D6*10/*10 patients (MMSE score change: 0.29±3.27) exhibited better therapeutic responses to DNP than did CYP2D6*1/*1 and CYP2D6*1/*10 patients (p=0.033). Patients who were ApoE E3 non-carriers and who had the CYP2D6*10/*10 genotype exhibited a trend toward better clinical responses to DNP therapy.nnnCONCLUSIONSnThe ApoE E3 allele and the CYP2D6 rs1065852 polymorphism may provide clinically relevant information for predicting therapeutic responses to DNP therapy.

Chinese Herbal Medicines as an Adjunctive Therapy for Unresectable Pancreatic Cancer: A Systematic Review and Meta-Analysis

Pancreatic cancer is a common malignancy with a high mortality. Most patients present clinically with advanced pancreatic cancer. Moreover, the effect of radiotherapy or chemotherapy is limited. Complementary and alternative medicines represent exciting adjunctive therapies. In this study, we ascertained the beneficial and adverse effects of Chinese herbal medicine (CHM) in combination with conventional therapy for inoperable pancreatic cancer by using meta-analysis methods for controlled clinical trials. We extracted data for studies searched from six electronic databases that were searched and also assessed the methodological quality of the included studies. We evaluated the following outcome measures: 6-month and 1-year survival rate, objective response rate, disease control rate, quality of life, and adverse effects. The final analysis showed CHM is a promising strategy as an adjunctive therapy to treat advanced or inoperable pancreatic cancer and that CHM in combination with conventional therapy is a promising strategy for resistant disease. However, convincing evidence must be obtained and confirmed by high-quality trials in future studies.

Orphan nuclear receptor NR4A2 inhibits hepatic stellate cell proliferation through MAPK pathway in liver fibrosis

Hepatic stellate cells (HSCs) play a crucial role in liver fibrosis, which is a pathological process characterized by extracellular matrix accumulation. NR4A2 is a nuclear receptor belonging to the NR4A subfamily and vital in regulating cell growth, metabolism, inflammation and other biological functions. However, its role in HSCs is unclear. We analyzed NR4A2 expression in fibrotic liver and stimulated HSCs compared with control group and studied the influence on cell proliferation, cell cycle, cell apoptosis and MAPK pathway after NR4A2 knockdown. NR4A2 expression was examined by real-time polymerase chain reaction, Western blotting, immunohistochemistry and immunofluorescence analyses. NR4A2 expression was significantly lower in fibrotic liver tissues and PDGF BB or TGF-β stimulated HSCs compared with control group. After NR4A2 knockdown α-smooth muscle actin and Col1 expression increased. In addition, NR4A2 silencing led to the promotion of cell proliferation, increase of cell percentage in S phase and reduced phosphorylation of ERK1/2, P38 and JNK in HSCs. These results indicate that NR4A2 can inhibit HSC proliferation through MAPK pathway and decrease extracellular matrix in liver fibrogenesis. NR4A2 may be a promising therapeutic target for liver fibrosis.

Stereoselective metabolism of donepezil and steady-state plasma concentrations of S-donepezil based on CYP2D6 polymorphisms in the therapeutic responses of Han Chinese patients with Alzheimer's disease☆

The therapeutic response rates of patients to donepezil vary from 20% to 60%, one of the reasons is their genetic differences in donepezil-metabolizing enzymes, which directly influence liver metabolism. However, the mechanism of donepezil metabolism and that of its enantiomers is unknown. This study evaluated CYP2D6 polymorphisms to elucidate the stereoselective metabolism of donepezil and to confirm the association between the steady-state plasma concentrations of the pharmaco-effective S-donepezil and the therapeutic responses of Han Chinese patients with Alzheimers disease. The inxa0vitro study of the stereoselective metabolism demonstrated that CYP2D6 is the predominant P450 enzyme that metabolizes donepezil and that different CYP2D6 alleles differentially affect donepezil enantiomers metabolism. A total of 77 Han Chinese patients with Alzheimers disease were recruited to confirm these results, by measuring their steady-state plasma concentrations of S-donepezil. The related CYP2D6 genes were genotyped. Plasma concentrations of S-donepezil (based on CYP2D6 polymorphisms) were significantly associated with therapeutic responses. This findingxa0suggests that plasma concentrations of S-donepezil influence therapeutic outcomes following treatment with donepezil in Han Chinese patients with Alzheimers disease. Therefore, determining a patients steady-state plasma concentration of S-donepezil in combination with their CYP2D6 genotype might be useful for clinically monitoring the therapeutic efficacy of donepezil.

Serum and urine metabolomics study reveals a distinct diagnostic model for cancer cachexia

Cachexia is a multifactorial metabolic syndrome with high morbidity and mortality in patients with advanced cancer. The diagnosis of cancer cachexia depends on objective measures of clinical symptoms and a history of weight loss, which lag behind disease progression and have limited utility for the early diagnosis of cancer cachexia. In this study, we performed a nuclear magnetic resonance‐based metabolomics analysis to reveal the metabolic profile of cancer cachexia and establish a diagnostic model.

Scutellarin protects against doxorubicin-induced acute cardiotoxicity and regulates its accumulation in the heart

The clinical use of doxorubicin (DOX) is limited by its dose-dependent cardiotoxicity. The present study investigated the effects of scutellarin against DOX-induced cardiotoxicity in rats using pharmacodynamic and pharmacokinetic approaches. DOX (20xa0mg/kg) was injected intraperitoneally (i.p.) as a single dose, and scutellarin (5xa0mg/kg/day) was injected intravenously (i.v.) for 3xa0days. Rats treated with DOX showed acute cardiotoxicity as indicated by the elevated serum lactate dehydrogenase (LDH) activity (4057.8xa0±xa0107.2 vs. 2032.7xa0±xa070.95), tissue malondialdehyde (MDA) level (2.083xa0±xa00.10 vs. 1.103xa0±xa00.09), cardiac troponin T (cTnT) concentration (0.1695xa0±xa00.0114xa0ng/mL), the decreased left ventricular ejection fraction (LVEF) (47.75xa0±xa015.79 vs. 78.72xa0±xa07.25) and left ventricular fractional shortening (LVFS) (20.66xa0±xa08.06 vs. 43.7xa0±xa06.76) compared with those of the control group. Cotreatment with scutellarin significantly decreased the LDH activity (2595.9xa0±xa072.73), MDA level (1.380xa0±xa00.06), cTnT concentration (0.0222xa0±xa00.0041xa0ng/m L), increased LVEF (76.70xa0±xa03.91) and LVFS (40.28xa0±xa03.68). Histopathological studies showed disruption of cardiac tissues in the DOX groups. Cotreatment with scutellarin reduced the damage to cardiac tissues. In the pharmacokinetic and tissue distribution study, scutellarin reduced the heart tissue exposure to DOX but did not change the AUC of plasma. These results suggest that scutellarin can protect against DOX-induced acute cardiotoxicity through its antioxidant activity and alterations of heart concentrations.

Acetylcholinesterase inhibitor donepezil effects on plasma β-hydroxybutyrate levels in the treatment of Alzheimer's disease.

BACKGROUNDnAlzheimers disease (AD) is a complex neurodegenerative disorder characterized by a multi-factorial etiology that is not completely understood. Donepezil is a first-line acetylcholinesterase inhibitor used for the treatment of AD that has been found, in addition to its potent acetylcholinesterase inhibitory effect, to act through other non-cholinergic mechanisms such as affecting mitochondrial biogenesis through peroxisome proliferator-activated receptor gamma coactivator (PGC1α). Mitochondrial biogenesis and PGC-1α, at least in part, are associated with hepatic fatty acid oxidation and ketogenesis. Whether donepezil regulates ketogenesis in AD treatment remains unclear. Ketogenesis is important in the progression of AD and is a critical consideration during the therapeutic strategy selection for AD. Thus, our goals were to determine the differences in ketone bodies in patients with AD who were taking donepezil treatment and those who were not, to elucidate the potential effect of AD and donepezil therapy on ketone body metabolic parameters, and to discover the effect of donepezil therapy on ketogenesis in patients with AD.nnnMETHODSnCross-sectional analysis was performed on plasma collected from 145 individuals, namely, elderly adults as healthy controls (n=30), newly diagnosed patients with AD (n=30), patients with AD who responded to donepezil therapy (n=48) and patients with AD who did not respond to donepezil therapy (n=37). Gas chromatography-mass spectrometry was performed to quantify the lipids in the plasma. The level of β-hydroxybutyrate, a metabolite, was determined by liquid chromatographytandem mass spectrometry, and to gain further insight into the effect of donepezil on ketogenesis, the effects of donepezil were investigated in a mouse model.nnnRESULTSnThe level of β-hydroxybutyrate decreased in AD patients, and donepezil elevated the plasma level of β-hydroxybutyrate. Donepezil increased the plasma and liver levels of β-hydroxybutyrate in mice as well as the hepatic expression of PGC-1α and the mitochondrial expression of HMG-CoA synthetase 2 (HMGCS2) in response to fasting, causing a subsequent increase in ketogenesis.nnnCONCLUSIONSnOur study revealed that impaired ketogenesis is a metabolic feature of AD. Donepezil had effects on ketogenesis in mice and reversed the decrease in the level of β-hydroxybutyrate found in patients with AD.