In the majority of patients, epilepsy is a complex disorder with multiple susceptibility genes interacting with environmental factors. However, we understand little about its genetic risks. Here, we ...report the first genome-wide association study (GWAS) to identify common susceptibility variants of epilepsy in Chinese. This two-stage GWAS included a total of 1087 patients and 3444 matched controls. In the combined analysis of the two stages, the strongest signals were observed with two highly correlated variants, rs2292096 G P= 1.0 × 10−8, odds ratio (OR) = 0.63 and rs6660197 T (P= 9.9 × 10−7, OR = 0.69), with the former reaching genome-wide significance, on 1q32.1 in the CAMSAP1L1 gene, which encodes a cytoskeletal protein. We also refined a previously reported association with rs9390754 (P= 1.7 × 10−5) on 6q21 in the GRIK2 gene, which encodes a glutamate receptor, and identified several other loci in genes involved in neurotransmission or neuronal networking that warrant further investigation. Our results suggest that common genetic variants may increase the susceptibility to epilepsy in Chinese.
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Pregnane X receptor (PXR; NR1I2) is a member of the superfamily of nuclear receptors that regulates the expression of genes involved in various biological processes, including drug ...transport and biotransformation. In the present study, we investigated the effect of 3-hydroxyflavone and its structurally-related analogues on PXR activity. 3-Hydroxyflavone, galangin, kaempferol, querceetin, isorhamnetin, and tamarixetin, but not but not datiscetin, morin, myricetin, or syringetin, activated mouse PXR, as assessed in a cell-based reporter gene assay. By comparison, 3-hydroxyflavone activated rat PXR, whereas 3-hydroxyflavone, galangin, quercetin, isorhamnetin, and tamarixetin activated human PXR (hPXR). A time-resolved fluorescence resonance energy transfer competitive ligand-binding assay showed binding to the ligand-binding domain of hPXR by 3-hydroxyflavone, galangin, quercetin, isorhamnetin, and tamarixetin. 3-Hydroxyflavone and galangin, but not quercetin, isorhamnetin, or tamarixetin, recruited steroid receptor coactivator (SRC)-1, SRC-2, and SRC-3 to hPXR. In LS180 human colon adenocarcinoma cells, 3-hydroxyflavone, quercetin, and tamarixetin increased CYP3A4, CYP3A5, and ABCB1 mRNA expression, whereas galangin and isorhamnetin increased CYP3A4 and ABCB1 but not CYP3A5 mRNA expression. Datiscetin, kaempferol, morin, myricetin, and syringetin did not attenuate the extent of hPXR activation by rifampicin, suggesting they are not hPXR antagonists. Overall, flavonols activate PXR in an analogue-specific and species-dependent manner. Substitution at the C2′ or C5′ position of 3-hydroxyflavone with a hydroxyl or methoxy group rendered it incapable of activating hPXR. Understanding the structure-activity relationship of flavonols in hPXR activation may facilitate nutraceutical development efforts in the treatment of PXR-associated intestinal diseases, such as inflammatory bowel disease.
Chemotherapy-induced nausea and vomiting (CINV) are common with doxorubicin-cyclophosphamide (AC) chemotherapy. Recommended antiemetic regimens incorporate neurokinin-1 receptor antagonist (NK1RA), ...5-hydroxytryptamine type-3 receptor antagonist (5HT3RA), corticosteroid, and dopamine antagonists. This post-hoc analysis compared results of 3 prospective antiemetic studies conducted among Chinese breast cancer patients who received (neo)adjuvant AC, in order to identify optimal antiemetic prophylaxis.
A total of 304 patients were included: Group 1, ondansetron/dexamethasone (D1); Group 2, aprepitant/ondansetron/dexamethasone (D1); Group 3, aprepitant/ondansetron/dexamethasone (D1-3); Group 4, aprepitant/ondansetron/dexamethasone (D1-3)/olanzapine; and Group 5, netupitant/palonosetron/dexamethasone (D1-3). Antiemetic efficacies of Groups 3, 4, and 5 during cycle 1 of AC were individually compared with Group 1. In addition, emesis outcomes of patients in Groups 3 and 5, and those of Groups 2 and 3, were compared.
When comparing efficacies of a historical doublet (5HT3RA/dexamethasone) with triplet antiemetic regimens (NK1RA/5HT3RA/dexamethasone) with/without olanzapine, complete response (CR) percentages and quality of life (QOL) in overall phase of cycle 1 AC were compared between Group 1 and the other groups: Group 1
3, 41.9%
38.3% (
= 0.6849); Group 1
4, 41.9%
65.0% (
= 0.0107); and Group 1
5, 41.9%
60.0% (
= 0.0460). Groups 4 and 5 achieved a better QOL. When comparing netupitant-based (Group 3) with aprepitant-based (Group 5) triplet antiemetics, CR percentages were 38.3%
60.0%, respectively (
= 0.0176); Group 5 achieved a better QOL. When comparing 1 day (Group 2)
3 day (Group 3) dexamethasone, CR percentages were 46.8% and 38.3%, respectively (
= 0.3459); Group 3 had a worse QOL.
Aprepitant-containing triplets were non-superior to doublet antiemetics. Netupitant-containing triplets and adding olanzapine to aprepitant-containing triplets were superior to doublets. Netupitant/palonosetron/dexamethasone was superior to aprepitant/ondansetron/dexamethasone. Protracted administration of dexamethasone provided limited additional benefit.
Paraneoplastic neurological syndromes are independent of metastasis, direct tumour infiltration, or known indirect mechanisms such as toxicity, ectopic hormone secretion, or induced coagulopathies.1 ...Paraneoplastic neurological syndromes may affect any part of the nervous system, and are believed to result when an immunologic response is directed against shared antigens that are ectopically expressed by the tumour, but otherwise predominantly expressed by the nervous system (onconeural antigens).1 Antibodies can be detected in the serum or cerebrospinal fluid of many, but not all, patients with PNS.2 Diagnosing PNS requires identification of the type of neurological syndrome based on neurological signs and symptoms, the detection of well-characterised onconeural antibodies, and the presence of a cancer.3 Paraneoplastic neurological syndromes are rare in patients with solid tumours, and probably even rarer among patients with lymphomas.4 The predominant types of PNS in lymphomas are paraneoplastic cerebellar degeneration in Hodgkin's lymphoma, and dermatomyositis/polymyositis in both Hodgkin's lymphoma and non-Hodgkin's lymphoma. Traditionally considered a variant of multiple sclerosis, presence of the disease-specific aquaporin-4 antibody, which plays a direct role in the pathogenesis of NMOSD, distinguishes the two entities.5 Recently, NMOSD is increasingly recognised as a paraneoplastic disorder especially in men or in patients who present in older age.6 Paraneoplastic NMOSD has been reported in a wide variety of tumour histological types but mostly in solid tumours.6 We recently encountered a definite case of PNS in a patient who was diagnosed with mantle cell lymphoma (MCL) and shortly afterwards developed neurological symptoms due to NMOSD. Early recognition of a neurological syndrome as paraneoplastic often leads to the discovery and treatment of the underlying tumour, which is a crucial step in the management of the PNS.1 2 Author contributions All authors have made substantial contributions to the concept or design; acquisition of data; analysis or interpretation of data; drafting of the article; and critical revision for important intellectual content.
Conflicting data exist on the effect of ginsenosides on transactivation of human glucocorticoid receptor α (herein referred to as glucocorticoid receptor), and relatively little is known regarding ...the effect of these chemicals on transrepression of this receptor. We investigated the effect of 20(S)-protopanaxadiol (PPD), PPD-type ginsenosides (Rb1, Rb2, Rc, Rd, Rh2, and Compound K), 20(S)-protopanaxatriol (PPT), and PPT-type ginsenosides (Re, Rf, Rg1, and Rh1) on glucocorticoid receptor binding, transactivation, and transrepression. Each ginsenoside was less efficacious than dexamethasone (positive control) in binding to the ligand-binding domain of glucocorticoid receptor. Among the ginsenosides investigated, Rh2 had the smallest IC50 value (15 ± 1µM), whereas it was 0.02 ± 0.01µM for dexamethasone. In contrast to dexamethasone, none of the ginsenosides influenced glucocorticoid receptor transactivation or transrepression in LS180 human colorectal adenocarcinoma cells, as assessed in a dual-luciferase reporter gene assay. Rh2 did not affect the endogenous mRNA level of tyrosine aminotransferase (marker for glucocorticoid receptor transactivation) or corticosteroid-binding globulin (marker for glucocorticoid receptor transrepression) in HepG2 human hepatocellular carcinoma cells. This chemical also did not alter the response by a glucocorticoid receptor agonist (dexamethasone or Compound A) in the dual-luciferase reporter gene assay or target gene expression assay. In conclusion, ginsenosides were less efficacious and less potent than dexamethasone in binding to the ligand-binding domain of glucocorticoid receptor. The number of glycosylated groups was associated with a decrease in receptor binding potency. PPD-type and PPT-type ginsenosides are not modulators of glucocorticoid receptor transactivation or transrepression in LS180 and HepG2 cells.
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An effective vaccine for hepatitis C virus (HCV) is a major unmet need, and it requires an antigen that elicits immune responses to key conserved epitopes. Based on structures of antibodies targeting ...HCV envelope glycoprotein E2, we designed immunogens to modulate the structure and dynamics of E2 and favor induction of broadly neutralizing antibodies (bNAbs) in the context of a vaccine. These designs include a point mutation in a key conserved antigenic site to stabilize its conformation, as well as redesigns of an immunogenic region to add a new N-glycosylation site and mask it from antibody binding. Designs were experimentally characterized for binding to a panel of human monoclonal antibodies (HMAbs) and the coreceptor CD81 to confirm preservation of epitope structure and preferred antigenicity profile. Selected E2 designs were tested for immunogenicity in mice, with and without hypervariable region 1, which is an immunogenic region associated with viral escape. One of these designs showed improvement in polyclonal immune serum binding to HCV pseudoparticles and neutralization of isolates associated with antibody resistance. These results indicate that antigen optimization through structure-based design of the envelope glycoproteins is a promising route to an effective vaccine for HCV.
Hepatitis C virus infects approximately 1% of the world's population, and no vaccine is currently available. Due to the high variability of HCV and its ability to actively escape the immune response, a goal of HCV vaccine design is to induce neutralizing antibodies that target conserved epitopes. Here, we performed structure-based design of several epitopes of the HCV E2 envelope glycoprotein to engineer its antigenic properties. Designs were tested
and
, demonstrating alteration of the E2 antigenic profile in several cases, and one design led to improvement of cross-neutralization of heterologous viruses. This represents a proof of concept that rational engineering of HCV envelope glycoproteins can be used to modulate E2 antigenicity and optimize a vaccine for this challenging viral target.
Cytochrome P450 2B6 (CYP2B6) is expressed predominantly in human liver. It catalyzes the oxidative biotransformation of various drugs, including bupropion, which is an antidepressant and a tobacco ...use cessation agent. Serious adverse effects of high dosages of bupropion have been reported, including the onset of seizure. As Ginkgo biloba extract may be consumed with bupropion or another CYP2B6 drug substrate, potential exists for an herb-drug interaction. Therefore, we investigated the effect of G. biloba extract and some of its chemical constituents (terpene trilactones and flavonols) on the in vitro catalytic activity of CYP2B6 as assessed by the bupropion hydroxylation assay with recombinant enzyme and hepatic microsomes. The amount of hydroxybupropion was quantified by a novel and validated ultraperformance liquid chromatography/mass spectrometry method. Enzyme kinetic analysis indicated that G. biloba extract competitively inhibited hepatic microsomal CYP2B6-catalyzed bupropion hydroxylation (apparent K(i) was 162 +/- 14 microg/ml). Bilobalide and ginkgolides A, B, C, and J were not responsible for the inhibition of CYP2B6 catalytic activity by the extract. Whereas the 3-O-glucoside and 3-O-rutinoside of quercetin, kaempferol, and isorhamnetin had no effect, the corresponding aglycones (10 and 50 microg/ml) decreased hepatic microsomal bupropion hydroxylation. The inhibition of CYP2B6 by kaempferol was competitive (apparent K(i) was 10 +/- 1 microg/ml). In summary, G. biloba extract and its flavonol aglycones are naturally occurring inhibitors of in vitro CYP2B6 catalytic activity and bupropion hydroxylation. Future studies are needed to investigate whether G. biloba extract interacts in vivo with bupropion or other clinically important CYP2B6 drug substrates.
Ginkgo biloba extract activates pregnane X receptor (PXR), but how this occurs is not known. Therefore, we investigated the mechanism of PXR activation by the extract and the role of five individual ...terpene trilactones in the activation. In a cell-based reporter gene assay, G. biloba extract activated human PXR (hPXR), and at a concentration present in the extract, ginkgolide A, but not ginkgolide B, ginkgolide C, ginkgolide J, or bilobalide was partially responsible for the increase in hPXR activity of the extract. Likewise, in cultured human hepatocytes, only ginkgolide A contributed to the increase in hPXR target gene expression (CYP3A4 mRNA and CYP3A-mediated testosterone 6β-hydroxylation). The extract, but none of the terpene trilactones, bound to hPXR ligand-binding domain, as analyzed by a time-resolved fluorescence resonance energy transfer competitive binding assay. Only the extract and ginkgolide A recruited steroid receptor coactivator-1, as determined by a mammalian two-hybrid assay. Compared with hPXR, rat PXR (rPXR) was activated to a lesser extent by G. biloba extract. Similar to hPXR, only ginkgolide A contributed to rPXR activation by the extract. In contrast to the effect of G. biloba extract on PXR function, it did not affect hPXR expression. Overall, the main conclusions are that G. biloba extract is an hPXR agonist, and among the five terpene trilactones investigated, only ginkgolide A contributes to the actions of the extract. Our findings provide insights into the biological and chemical mechanisms of hPXR activation by G. biloba extract.
The naturally occurring SV23 splice variant of human constitutive androstane receptor (hCAR-SV23) is activated by di-(2-ethylhexyl)phthalate (DEHP), which is detected as a contaminant in fetal bovine ...serum (FBS). In our initial experiment, we compared the effect of dialyzed FBS, charcoal-stripped, dextran-treated FBS (CS-FBS), and regular FBS on the basal activity and ligand-activation of hCAR-SV23 in a cell-based reporter gene assay. In transfected HepG2 cells cultured in medium supplemented with 10% FBS, basal hCAR-SV23 activity varied with the type of FBS (regular>dialyzed>CS). DEHP increased hCAR-SV23 activity when 10% CS-FBS, but not regular FBS or dialyzed FBS, was used. With increasing concentrations (1–10%) of regular FBS or CS-FBS, hCAR-SV23 basal activity increased, whereas in DEHP-treated cells, hCAR-SV23 activity remained similar (regular FBS) or slightly increased (CS-FBS). Subsequent experiments identified a serum-free culture condition to detect DEHP activation of hCAR-SV23. Under this condition, artemisinin, artemether, and arteether increased hCAR-SV23 activity, whereas they decreased it in cells cultured in medium supplemented with 10% regular FBS. By comparison, FBS increased the basal activity of the wild-type isoform of hCAR (hCAR-WT), whereas it did not affect the basal activity of the SV24 splice variant (hCAR-SV24) or ligand activation of hCAR-SV24 and hCAR-WT by 6-(4-chlorophenyl)imidazo2,1-b1,3thiazole-5-carbaldehyde O-(3,4-dichlorobenzyl)oxime (CITCO). The use of serum-free culture condition was suitable for detecting CITCO activation of hCAR-WT and hCAR-SV24. In conclusion, FBS leads to erroneous classification of pharmacological ligands of hCAR-SV23 in cell-based assays, but investigations on functional ligands of hCAR isoforms can be conducted in serum-free culture condition.
•FBS leads to erroneous pharmacological classification of hCAR-SV23 ligands.•Artemisinin, artemether, and arteether activate hCAR-SV23 in the absence of FBS.•Serum-free culture condition can be used for identifying ligands of hCAR isoforms.
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