OBJECTIVE: The multidrug resistance 1 (ABCB1, MDR1) gene, encoding P-glycoprotein, is extensively distributed and expressed in various tissues, such as a blood-brain barrier transporter. P-glycoprotein plays an important role in controlling the passage of substances between the blood and brain. The current study aimed to investigate possible associations of functional ABCB1 polymorphisms (C3435T, G2677T and C1236T) with response to antidepressant treatment and serum cortisol levels in Taiwanese patients with major depressive disorder (MDD). METHODS: We recruited 112 MDD patients who were randomized to fluoxetine (n=58, mean dose: 21.4+/-4.5 mg/day) or venlafaxine (n=54, 80.2+/-34.7 mg/day) treatment for 6 weeks. The 21-item Hamilton Depression Rating Scale (HDRS) was administered initially and biweekly after treatment, and cortisol levels were assessed initially and after 6-week antidepressant treatment. RESULTS: The initial HDRS scores and the HDRS scores after six weeks of antidepressant treatment were not significantly different among the different genotypes in each polymorphism of ABCB1. The percentage changes of HDRS scores over time were significantly different in the polymorphisms of ABCB1 G2677T (p=0.002). MDD patients with the G/G genotype of ABCB1 G2677T had a worse antidepressant treatment response. However, the polymorphisms of ABCB1 genotypes were not significantly associated with cortisol levels before and after antidepressant treatment in MDD patients. CONCLUSION: The results suggested that the variants of ABCB1 may influence the short-term antidepressant response in MDD patients. Further details of the underlying mechanisms of ABCB1 in antidepressant treatment remain to be clarified.
Antidepressive Agents ; Blood-Brain Barrier ; Brain ; Depression ; Depressive Disorder, Major ; Drug Resistance, Multiple ; Fluoxetine ; Genotype ; Humans ; Hydrocortisone ; P-Glycoprotein ; P-Glycoproteins ; Venlafaxine Hydrochloride

BACKGROUND: Diffuse large B-cell lymphoma (DLBCL) is the most common type of malignant lymphoma which responds well to conventional chemotherapy. However, quite a few patients have a recurrence with more aggressive forms after completion of therapy. Multidrug resistance proteins (MRP) are related to this process in several ways such as cell cycle alteration and modulation of apoptosis. METHODS: We investigated the expression of P-glycoprotein (Gp), one of the well-known MRP, as well as apoptosis associated proteins in DLBCL. Immunohistochemical staining for Gp, p53, Bcl-2, Ki-67, active caspase 3 and FADD was done in forty DLBCL cases. The association between MRP and apoptosis associated proteins to clinical findings was also tested. RESULTS: Twenty-nine patients out of 40 (73%) with DLBCL were positive for Gp, and 26 cases (65%) had a strong positive for Gp. Gp expression was stronger in high-grade lesions than in low-grade lesions and was associated to Bcl-2 expression. However, we could not find an adverse impact of Gp expression on patients' overall survival or relapse free survival rate. CONCLUSIONS: Our study revealed a high frequency of expression for Gp in DLBCL with a possible relationship between the expressions of Gp to apoptosis associated proteins.
Apoptosis ; B-Lymphocytes ; Caspase 3 ; Cell Cycle ; Humans ; Lymphoma ; Lymphoma, B-Cell ; Lymphoma, Large B-Cell, Diffuse ; P-Glycoprotein ; P-Glycoproteins ; Proteins ; Recurrence ; Survival Rate

BACKGROUND/AIMS: Simvastatin has dramatically reduced cardiovascular disease due to elevated cholesterol. The human multidrug resistance 1 gene (MDR1) encodes a 170-kDa transmembrane glycoprotein (P-glycoprotein), which plays an important role in regulating the absorption, distribution, and excretion of simvastatin. To clarify the effects of the MDR1 gene polymorphism on simvastatin pharmacokinetics, we investigated whether there is an association between genotype and the pharmacokinetic parameters for simvastatin. METHODS: Thirty-one healthy unrelated Korean volunteers were genotyped for MDR1. Genomic DNA from blood was analyzed using the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). Following an overnight fast, all of the subjects took a single 60-mg oral dose of simvastatin. Venous blood samples were taken for 12 hours after the oral drug intake. A statistical analysis of the MDR1 genotype and pharmacokinetic parameters of simvastatin was performed. RESULTS: The mean Tmax of the 1236TT genotype was significantly higher than that of CT and CC (p=0.02). The mean AUC0-12h of 3435TT was also significantly higher, compared with CT and CC (p=0.01). No significant difference was observed between the MDR1 single nucleotide polymorphism (SNP) for G2677A/T and the pharmacokinetic parameters. CONCLUSIONS: These findings suggest that polymorphic MDR1 genes are important in the inter-individual variation of the disposition of simvastatin in humans. s
Absorption ; Cardiovascular Diseases ; Cholesterol ; DNA ; Drug Resistance, Multiple ; Genotype ; Glycoproteins ; Humans ; P-Glycoprotein ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; Polymorphism, Single Nucleotide ; Simvastatin

We have studied the patterns of P-glycoprotein expression before and after 3 cycles of induction chemotherapy (5-fluorouracil, adriamycin and cyclophosphamide) using immunohistochemically stained paraffin-embedded specimen of 28 patients with locally advanced breast cancer. The frequency of P-glycoprotein expression in untreated breast cancer turned out to be very low: only one out of 28 untreated, biopsy specimen at the time of diagnosis was positive. The frequency of P-glycoprotein expression was markedly increased from 9.1% before chemotherapy to 63.6% after induction chemotherapy (p = 0.006). After 3 cycles of induction chemotherapy, 25 patients had obtained clinical response to chemotherapy (4, CR; 21, PR). Eleven out of 25 tumors (44%) showing clinical response and all three tumors (100%) with minimal response have expressed P-glycoprotein. One out of 6 patients (16.7%) with microscopic residual tumor seen in mastectomy specimen expressed P-glycoprotein, whereas 13 of 22 patients (59.1%) with gross residual tumor showed the presence of P-glycoprotein (p = 0.08). The frequency of intrinsic P-glycoprotein expression in untreated breast cancer was quite low, but approximately half of the patients do acquire P-glycoprotein expression during the cycles of induction chemotherapy. Therefore, the results suggest that the immunohistochemical detection of P-glycoprotein on residual tumor cells after induction chemotherapy can predict acquired drug resistance in breast cancer.
Adult ; Aged ; Breast Neoplasms/chemistry/*drug therapy/pathology ; Breast Neoplasms/chemistry/*drug therapy/pathology ; Drug Resistance ; Drug Resistance ; Female ; Human ; Immunohistochemistry ; Membrane Glycoproteins/*analysis ; Middle Age ; P-Glycoprotein

This study was purposed to explore the influence of S-nitrosoglutathione (GSNO) on membrane glycoprotein of frozen platelet. The levels of membrane glycoprotein on fresh liquid platelets, frozen platelets and frozen platelets with GSNO were measured by flow cytometry. The results showed that the GSNO obviously decreased platelet aggregation, the PAC-1 change in the three groups was not significant. The changes of CD42b and CD62P in fresh liquid platelet group, frozen platelet group and frozen platelets with GSNO were significant different. The change of membrane glycoprotein in above-mentioned three group was not significant. It is concluded that the GSNO inhibits platelet aggregation, maintains the function of platelets and may be used as a cryoprotectant. When frozen platelets were added with GSNO, the molecular rearrangement, structure change and other mechanism may occur in platelets.
Blood Platelets ; drug effects ; Blood Preservation ; methods ; Freezing ; Humans ; P-Selectin ; metabolism ; Platelet Activation ; drug effects ; Platelet Glycoprotein GPIb-IX Complex ; metabolism ; Platelet Membrane Glycoproteins ; metabolism ; S-Nitrosoglutathione ; pharmacology

BACKGROUND: Selenoprotein P (SEPP1) and fetuin-A, both circulating liver-derived glycoproteins, are novel biomarkers for insulin resistance and nonalcoholic fatty liver disease. However, the effect of exendin-4 (Ex-4), a glucagon-like peptide-1 receptor agonist, on the expression of hepatokines, SEPP1, and fetuin-A, is unknown. METHODS: The human hepatoma cell line HepG2 was treated with palmitic acid (PA; 0.4 mM) and tunicamycin (tuni; 2ug/ml) with or without exendin-4 (100 nM) for 24 hours. The change in expression of PA-induced SEPP1, fetuin-A, and endoplasmic reticulum (ER) stress markers by exendin-4 treatment were evaluated using quantitative real-time reverse transcription polymerase chain reaction and Western blotting. Transfection of cells with AMP-activated protein kinase (AMPK) small interfering RNA (siRNA) was performed to establish the effect of exendin-4-mediated AMPK in the regulation of SEPP1 and fetuin-A expression. RESULTS: Exendin-4 reduced the expression of SEPP1, fetuin-A, and ER stress markers including PKR-like ER kinase, inositol-requiring kinase 1alpha, activating transcription factor 6, and C/EBP homologous protein in HepG2 cells. Exendin-4 also reduced the expression of SEPP1 and fetuin-A in cells treated with tunicamycin, an ER stress inducer. In cells treated with the AMPK activator 5-aminoidazole-4-carboxamide ribonucleotide (AICAR), the expression of hepatic SEPP1 and fetuin-A were negatively related by AMPK, which is the target of exendin-4. In addition, exendin-4 treatment did not decrease SEPP1 and fetuin-A expression in cells transfected with AMPK siRNA. CONCLUSION: These data suggest that exendin-4 can attenuate the expression of hepatic SEPP1 and fetuin-A via improvement of PA-induced ER stress by AMPK.
Activating Transcription Factor 6 ; alpha-2-HS-Glycoprotein* ; AMP-Activated Protein Kinases* ; Blotting, Western ; Carcinoma, Hepatocellular ; Cell Line ; Endoplasmic Reticulum ; Endoplasmic Reticulum Stress* ; Fatty Liver ; Glucagon-Like Peptide 1 ; Glycoproteins ; Hep G2 Cells ; Humans ; Insulin Resistance ; Palmitic Acid ; Phosphotransferases ; Polymerase Chain Reaction ; Reverse Transcription ; RNA, Small Interfering ; Selenoprotein P ; Transfection ; Tunicamycin ; Biomarkers ; Glucagon-Like Peptide-1 Receptor

To investigate the pathophysiological mechanisms for platelet-neutrophils cross talk mediated by platelet-activating factor (PAF) and to lay a foundation for clinical application, ginkgolides B (GB), a PAF receptor antagonist, was added in the whole blood to block the effects of PAF on activation of platelet-neutrophil; PAF and ADP were respectively added in the whole blood to monitor the expression of CD62P on platelet by flow cytometry; PAF and ADP were added in the whole blood to monitor the expression of CD11b on neutrophil by flow cytometry; PAF and ADP were added in the whole blood to monitor the platelet-leucocyte aggregates (PLA) which were PLA in the total leucocyte population (PLA/L) and the mean fluorescence intensity (MFI) of CD42b. Outcomes were analyzed by t-test, and the differences were statistically significant (P < 0.05). The results showed that the expression of CD62P on platelats, the expression of CD11b on neutrophils and PLA formation were all increased by PAF and ADP; the PAF receptor antagonists (GB) could obviously inhibit the expression of CD62P, CD11b and PLA formation induced by PAF, but could not completely inhibit the activation of platelet and neutrophil, and the platelet-neutrophil cross talk; GB could inhibit the expression of CD62P and CD11b induced by ADP, but could not conpletely inhibit the activation of platelet and neutrophli; GB could not obviously inhibit the platelet-leucocyte aggregates mediated by ADP. It is concluded that the multiligand-receptor systems involved in PLA formation and platelet-netrophils cross talk seem to be regulated by complex mechanisms; the PAF receptor antagonists (GB) obviously inhibit the effect of PAF, and may be widely utilized in the therapy of thrombosis and inflammation.
Adenosine Diphosphate ; pharmacology ; Adult ; Blood Platelets ; cytology ; drug effects ; physiology ; CD11b Antigen ; blood ; Cell Adhesion ; drug effects ; physiology ; Cell Communication ; drug effects ; physiology ; Female ; Flow Cytometry ; Ginkgolides ; pharmacology ; Humans ; Male ; Middle Aged ; Neutrophils ; cytology ; drug effects ; physiology ; P-Selectin ; blood ; Platelet Activating Factor ; pharmacology ; Platelet Activation ; drug effects ; Platelet Glycoprotein GPIb-IX Complex ; analysis ; Platelet Membrane Glycoproteins ; antagonists & inhibitors ; physiology ; Receptors, G-Protein-Coupled ; antagonists & inhibitors ; physiology

P-selectin, one of the membrane proteins, expresses on platelet and endothelia and interacts with P-selectin glycoprotein ligand-1 (PSGL-1) on leukocyte membrane. This interaction mediates leukocytes rolling on endothelial membrane and then induces leukocyte recruitment to the site of infection or tissue injury. In the present study, we constructed the recombinant wild type human P-selectin, its calcium-binding sites mutants and recombinant PSGL-1-globulin (PSGL-1-Rg). They expressed in Sf9 cells by using the baculovirus expression system and were purified by TalonTM metal or Protein A affinity chromatography. The results showed that the recombinant PSGL-1-Rg interacted with recombinant wild type P-selectin and two P-selectin mutants with 2 calcium-binding sites mutation respectively, but could not bind to the P-selectin mutant with all 4 calcium-binding sites mutation. Therefore, we verified the importance of P-selectin calcium-binding sites for its interaction with PSGL-1.
Binding Sites ; Calcium ; metabolism ; Humans ; Leukocytes ; metabolism ; Membrane Glycoproteins ; metabolism ; Mutation ; P-Selectin ; metabolism ; Recombinant Proteins ; metabolism

P-selectin engagement of P-selectin glycoprotein ligand-1 (PSGL-1) causes circulating leukocytes to roll on and adhere to the vascular surface, and mediates intracellular calcium flux, a key but unclear event for subsequent arresting firmly at and migrating into the infection or injured tissue. Using a parallel plate flow chamber technique and intracellular calcium ion detector (Fluo-4 AM), the intracellular calcium flux of firmly adhered neutrophils on immobilized P-selectin in the absence of chemokines at various wall shear stresses was investigated here in real time by fluorescence microscopy. The results demonstrated that P-selectin engagement of PSGL-1 induced the intracellular calcium flux of firmly adhered neutrophils in flow, increasing P-selectin concentration enhanced cellular calcium signaling, and, force triggered, enhanced and quickened the cytoplasmic calcium bursting of neutrophils on immobilized P-selectin. This P-selectin-induced calcium signaling should come from intracellular calcium release rather than extracellular calcium influx, and be along the mechano-chemical signal pathway involving the cytoskeleton, moesin and Spleen tyrosine kinase (Syk). These results provide a novel insight into the mechano-chemical regulation mechanism for P-selectin-induced calcium signaling of neutrophils in flow.
Calcium Signaling ; Female ; Humans ; Male ; Membrane Glycoproteins ; metabolism ; Neutrophils ; metabolism ; P-Selectin ; metabolism ; Stress, Mechanical ; Syk Kinase ; metabolism

Objective To explore the function and mechanism of related genes in the occurrence and development of liver cancer, and the possibility of key genes as potential biomarkers and prognostic indicators for the treatment of liver cancer.Methods We selected 4 datasets(GSE57957, GSE121248, GSE36376 and GSE14520)from the GEO database.With
Biomarkers, Tumor/genetics* ; Carrier Proteins ; Computational Biology ; Cytochrome P-450 CYP2E1 ; Cytochrome P-450 CYP3A ; Gene Expression Profiling ; Gene Expression Regulation, Neoplastic ; Gene Regulatory Networks ; Glycoproteins ; Humans ; Liver Neoplasms/genetics* ; Prognosis ; Protein Interaction Maps