RESUMEN
CD8+ T cell exhaustion dampens antitumor immunity. Although several transcription factors have been identified that regulate T cell exhaustion, the molecular mechanisms by which CD8+ T cells are triggered to enter an exhausted state remain unclear. Here, we show that interleukin-2 (IL-2) acts as an environmental cue to induce CD8+ T cell exhaustion within tumor microenvironments. We find that a continuously high level of IL-2 leads to the persistent activation of STAT5 in CD8+ T cells, which in turn induces strong expression of tryptophan hydroxylase 1, thus catalyzing the conversion to tryptophan to 5-hydroxytryptophan (5-HTP). 5-HTP subsequently activates AhR nuclear translocation, causing a coordinated upregulation of inhibitory receptors and downregulation of cytokine and effector-molecule production, thereby rendering T cells dysfunctional in the tumor microenvironment. This molecular pathway is not only present in mouse tumor models but is also observed in people with cancer, identifying IL-2 as a novel inducer of T cell exhaustion.
Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Linfocitos T CD8-positivos/efectos de los fármacos , Interleucina-2/metabolismo , Linfocitos Infiltrantes de Tumor/efectos de los fármacos , Neoplasias/metabolismo , Receptores de Hidrocarburo de Aril/metabolismo , Microambiente Tumoral , 5-Hidroxitriptófano/metabolismo , Animales , Anticuerpos Neutralizantes/farmacología , Antineoplásicos/farmacología , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/deficiencia , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Regulación Neoplásica de la Expresión Génica , Células HCT116 , Células HEK293 , Humanos , Interleucina-2/antagonistas & inhibidores , Interleucina-2/genética , Células Jurkat , Linfocitos Infiltrantes de Tumor/inmunología , Linfocitos Infiltrantes de Tumor/metabolismo , Células MCF-7 , Melanoma Experimental/tratamiento farmacológico , Melanoma Experimental/inmunología , Melanoma Experimental/metabolismo , Melanoma Experimental/patología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Células 3T3 NIH , Neoplasias/tratamiento farmacológico , Neoplasias/inmunología , Neoplasias/patología , Receptores de Hidrocarburo de Aril/deficiencia , Receptores de Hidrocarburo de Aril/genética , Transducción de Señal , Triptófano Hidroxilasa/metabolismo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Two new p-hydroxybenzoic acid glycosides, namely p-hydroxybenzoic acid-4-O-α-d-manopyranosyl-(1 â 3)-α-l-rhamnopyranoside (compound 1) and 4-O-α-l-rhamnopyran-osyl-(1 â 6)-α-d-manopyranosyl-(1 â 3)-α-l-rhamnopyranoside (compound 2), and seven known compounds, compound 3, 6, 7 (acid components), compound 8, 9 (flavonoids), compound 4 (a coumarin) and compound 5 (an alkaloid), were isolated from the 70% ethanol aqueous extract of the aerial parts of Melilotus officinalis (Linn.) Pall. The structures of all compounds were elucidated by use of extensive spectroscopic methods Infrared Spectroscopy (IR), High resolution electrospray ionization mass spectrometry (HR-ESI-MS), and ¹H and 13C-NMR). Sugar residues obtained after acid hydrolysis were identified by high-performance liquid chromatography (HPLC). The antioxidant activity of all the compounds was evaluated by 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTSâº) and 1,1-diphenyl-2-picrylhydrazyl (DPPH). The anti-inflammatory effects of the compounds were also evaluated in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. All compounds were shown to inhibit LPS-induced nitric oxide (NO) and prostaglandin E 2 (PGE 2) production by suppressing the expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2), respectively, in LPS-stimulated RAW 264.7 cells. The inhibitory effect of all the compounds on MCF-7 cells was determined by Cell Counting Kit-8 (CCK-8) method. The results showed that compounds 1, 2, 7, 8, 9 exhibited better antioxidant activity compared to the other compounds. compounds 1-9 had different inhibitory effects on the release of NO, TNF-α and IL-6 in LPS-stimulated RAW264.7 cells by LPS, of which compound 7 was the most effective against inflammatory factors. compounds 1 and 2 have better antitumor activity compared to other compounds. Further research to elucidate the chemical composition and pharmacological effects of Melilotus officinalis (Linn.) Pall is of major importance towards the development and foundation of clinical application of the species.
Asunto(s)
Antiinflamatorios , Antineoplásicos Fitogénicos , Antioxidantes , Melilotus/química , Animales , Antiinflamatorios/química , Antiinflamatorios/farmacología , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/farmacología , Antioxidantes/química , Antioxidantes/farmacología , Humanos , Células MCF-7 , Ratones , Células RAW 264.7RESUMEN
Exhausted CD8+ T cells with limited effector functions and high expression of multiple co-inhibitory receptors are one of the main barriers hindering antitumor immunity. The NADase CD38 has received considerable attention as a biomarker of CD8+ T cell exhaustion, but it remains unclear whether the increased CD38 directly promotes T cell dysfunctionality. Here, we surprisingly found that although Cd38 deficiency partially reverses NAD+ degradation and T cell dysfunction in vitro, the terminal exhausted differentiation of adoptively transferred CD8+ T cells in tumor is not impacted by either deficiency or overexpression of CD38. Monitoring the dynamic NAD+ levels shows that NAD+ levels are comparable between tumor infiltrated WT and Cd38 -/- OT-1 cells. Therefore, our results suggest that decreased NAD+ are correlated with T cell dysfunction, but deficiency of CD38 is not enough for rescuing NAD+ in tumor infiltrated CD8+ T cells and fails to increase the efficacy of antitumor T cell therapy.
RESUMEN
It has been recently reported that CD38 expressed on tumor cells of multiple murine and human origins could be upregulated in response to PD-L1 antibody therapy, which led to dysfunction of tumor-infiltrating CD8+ T immune cells due to increasing the production of adenosine. However, the role of tumor expressed-CD38 on neoplastic formation and progression remains elusive. In the present study, we aimed to delineate the molecular and biochemical function of the tumor-associated CD38 in lung adenocarcinoma progression. Our clinical data showed that the upregulation of tumor-originated CD38 was correlated with poor survival of lung cancer patients. Using multiple in vitro assays we found that the enzymatic activity of tumor expressed-CD38 facilitated lung cancer cell migration, proliferation, colony formation, and tumor development. Consistently, our in vivo results showed that inhibition of the enzymatic activity or antagonizing the enzymatic product of CD38 resulted in the similar inhibition of tumor proliferation and metastasis as CD38 gene knock-out or mutation. At biochemical level, we further identified that cADPR, the mainly hydrolytic product of CD38, was responsible for inducing the opening of TRPM2 iron channel leading to the influx of intracellular Ca2+ and then led to increasing levels of NRF2 while decreasing expression of KEAP1 in lung cancer cells. These findings suggested that malignant lung cancer cells were capable of using cADPR catalyzed by CD38 to facilitate tumor progression, and blocking the enzymatic activity of CD38 could be represented as an important strategy for preventing tumor progression.
Asunto(s)
ADP-Ribosil Ciclasa 1/metabolismo , Adenocarcinoma del Pulmón/enzimología , ADP-Ribosa Cíclica/metabolismo , Neoplasias Pulmonares/enzimología , Glicoproteínas de Membrana/metabolismo , Células A549 , ADP-Ribosil Ciclasa 1/genética , Adenocarcinoma del Pulmón/genética , Adenocarcinoma del Pulmón/secundario , Animales , Señalización del Calcio , Carcinoma Pulmonar de Lewis/enzimología , Carcinoma Pulmonar de Lewis/genética , Carcinoma Pulmonar de Lewis/patología , Movimiento Celular , Proliferación Celular , Bases de Datos Genéticas , Progresión de la Enfermedad , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Proteína 1 Asociada A ECH Tipo Kelch/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Masculino , Glicoproteínas de Membrana/genética , Ratones Endogámicos C57BL , Persona de Mediana Edad , Factor 2 Relacionado con NF-E2/metabolismo , Invasividad Neoplásica , Canales Catiónicos TRPM/metabolismoRESUMEN
To elucidate the possible metabolic mechanism of intrauterine growth retardation induced by nicotine, this study determines the effects of prenatal nicotine exposure on fetal development and cytochrome P4501A1 (CYP1A1), CYP2E1, and P-glycoprotein (Pgp) expression in maternal liver and placenta. Pregnant rats were given 1.0 mg/kg nicotine subcutaneously twice a day from gestational day (GD) 8 to GD 15, 18, or 21. In nicotine-treated groups, fetal developmental parameters including body weight were significantly lower. The activities of CYP1A1 and CYP2E1 in maternal liver microsomes in nicotine-treated groups increased significantly with progressing gestation when compared with the corresponding control, but returned to the level similar to the control in late pregnancy. Nicotine-treated groups induced pathological changes and increased malondialdehyde (MDA) content in the placenta when compared with the control. The gene expressions of CYP1A1 and CYP2E1 in the placenta increased significantly in nicotine-treated groups on GD 15 and GD 18, but returned to the level similar to the corresponding control on GD 21. In nicotine group, there was a decrease of mdr1a expression on GD 15, GD 18, and GD 21, with the most significant decrease on GD 15. In contrast, no significant difference was found in mdr1b mRNA expression between the nicotine-treated animals and the corresponding control. In comparison with the corresponding control, the placental Pgp protein significantly decreased on GD 15 and GD 18. Our results showed that prenatal nicotine exposure resulted in inhibition of fetal growth significantly. The induction of CYP2E1 and CYP1A1 gene expression by nicotine in the maternal liver and placenta may be involved with the observed increase in oxidative stress and lipid peroxidation. The inhibition of the placental Pgp expression by nicotine may also contribute to an increased susceptibility of the fetus to environmental toxins.
Asunto(s)
Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Citocromo P-450 CYP1A1/metabolismo , Citocromo P-450 CYP2E1/metabolismo , Feto/efectos de los fármacos , Feto/embriología , Nicotina/efectos adversos , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/genética , Animales , Peso Corporal/efectos de los fármacos , Citocromo P-450 CYP1A1/genética , Citocromo P-450 CYP2E1/genética , Femenino , Feto/patología , Expresión Génica , Inmunohistoquímica , Hígado/efectos de los fármacos , Hígado/enzimología , Masculino , Nicotina/administración & dosificación , Placenta/efectos de los fármacos , Placenta/enzimología , Embarazo , ARN Mensajero/metabolismo , Ratas , Ratas Wistar , Organismos Libres de Patógenos EspecíficosRESUMEN
Despite the clinical successes fostered by immune checkpoint inhibitors, mechanisms underlying PD-1 upregulation in tumor-infiltrating T cells remain an enigma. Here, we show that tumor-repopulating cells (TRCs) drive PD-1 upregulation in CD8+ T cells through a transcellular kynurenine (Kyn)-aryl hydrocarbon receptor (AhR) pathway. Interferon-γ produced by CD8+ T cells stimulates release of high levels of Kyn produced by TRCs, which is transferred into adjacent CD8+ T cells via the transporters SLC7A8 and PAT4. Kyn induces and activates AhR and thereby upregulates PD-1 expression. This Kyn-AhR pathway is confirmed in both tumor-bearing mice and cancer patients and its blockade enhances antitumor adoptive T cell therapy efficacy. Thus, we uncovered a mechanism of PD-1 upregulation with potential tumor immunotherapeutic applications.
Asunto(s)
Linfocitos T CD8-positivos/efectos de los fármacos , Quinurenina/farmacología , Receptor de Muerte Celular Programada 1/efectos de los fármacos , Receptores de Hidrocarburo de Aril/efectos de los fármacos , Animales , Linfocitos T CD8-positivos/inmunología , Línea Celular Tumoral , Humanos , Interferón gamma/inmunología , Ratones , Receptor de Muerte Celular Programada 1/inmunología , Receptor de Muerte Celular Programada 1/metabolismo , Transducción de Señal/efectos de los fármacos , Transducción de Señal/inmunologíaRESUMEN
OBJECTIVE@#To observe the effect of moxibustion on proteins related with apoptosis of hippocampal neurons in rats with vascular dementia (VD), and to explore the possible mechanism of moxibustion on improving VD.@*METHODS@#Thirty SD rats were selected from 100 rats (3 rats were excluded) and randomly divided into a normal group and a sham operation group, 15 rats in each group. The remaining 67 rats were treated with ischemia-reperfusion method at bilateral common carotid artery to establish VD model. The 45 rats with successful VD model were randomly divided into a model group, a moxibustion group and a medication group, 15 rats in each group. On the 7th day after successful modeling, the rats in the moxibustion group were treated with suspended moxibustion at "Guanyuan" (CV 4), "Mingmen" (GV 4) and "Dazhui" (GV 14), 15 min per acupoint, once a day; there was 1 d of rest after 6 d of moxibustion, and the treatment was given for 4 weeks. The rats in the medication group was treated with nimodipine tablets by gavage, 2 mg/kg per day, 3 times a day for 4 weeks. Before and after intervention, the Morris water maze test was used to detect the escape latency of rats in each group; after the intervention, the TUNEL method was used to detect the apoptosis rate of neurons in hippocampal CA1 area; the immunofluorescence double labeling method was used to detect the number of co-expression positive cells of B-cell lymphoma-2 (Bcl-2)/neuronal nuclear antigen (NeuN) and Bcl-2-associated X protein (Bax)/NeuN in hippocampal CA1 area; the immunofluorescence single labeling method was used to detect cytochrome C (cytC) and outer mitochondrial membrane receptor Tom20 (Tom20) in hippocampal CA1 area; the Western blot method was used to detect the p53 upregulated modulator of apoptosis (PUMA) in hippocampus.@*RESULTS@#Before intervention, compared with the normal group and the sham operation group, the escape latency in the model group, the moxibustion group and the medication group was prolonged (@*CONCLUSION@#Moxibustion could improve the cognitive function of VD rats, which may be related to reducing the expression of Bax, cytC, Tom20 and PUMA protein in hippocampal CA1 area, promoting the release of Bcl-2 and inhibiting the apoptosis of hippocampal neurons.
Asunto(s)
Animales , Ratas , Apoptosis , Cognición , Demencia Vascular/terapia , Hipocampo , Moxibustión , Neuronas , Ratas Sprague-DawleyRESUMEN
OBJECTIVE@#To observe the eliminating effects of moxibustion at "Baihui" (GV 20), "Fengfu" (GV 16) and "Dazhui" (GV 14) on amyloid β-peptide (Aβ) in brain of the amyloid precursor protein/presenili1 (APP/PS1) double-transgenic mice with Alzheimer's disease (AD) by regulating the phosphoinositide 3-kinases/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) signaling pathway.@*METHODS@#A total of 60 APP/PS1 double-transgenic mice with AD were randomly divided into a model group, a moxibustion group, a rapamycin group and a combination group (treated with moxibustion and inhibitor), 15 mice in each group, another 15 male C57BL/6J mice with same age and background were selected as the control group. In the moxibustion group, pressing moxibustion was applied at "Baihui" (GV 20) while the mild moxibustion was applied at "Fengfu" (GV 16) and "Dazhui" (GV 14). The treatment was manipulated for 20 min each time, once a day for 2 weeks. In the rapamycin group, rapamycin (2 mg/kg) was given by intraperitoneal injection once a day for 2 weeks. On the basis of the treatment in the moxibustion group, 3-methyladenine (1.5 mg/kg) was given by intraperitoneal injection once a day for 2 weeks. The mice in the control and the model group received normal diet and no intervention was given for 2 weeks. Immunohistochemica method was used to measure the levels of Aβ in the cerebral cortex and hippocampal, transmission electron microscopy was used to observe the formation of autophagosome in hippocampus, and Western blot method was used to observe the levels of PI3K, Akt, p-Akt, mTOR and p-mTOR in hippocampus.@*RESULTS@#Compared with the control group, the levels of Aβ in the cerebral cortex and hippocampal were increased in the model group (0.05). Compared with the rapamycin group, the levels of Aβ in the cerebral cortex and hippocampal were increased in the combination group (<0.01). In the model group, the cytoplasmic utophagic vacuoles and organelles of neuron were reduced. In the moxibustion group, the utophagic vacuoles were increased, and the organelles showed deformation and atrophy. In the rapamycin group, the utophagic vacuoles were widely disturbed and few deformed organelles were found. In the combination group, few utophagic vacuoles were found and additional organelles showed deformation and atrophy. Compared with the control group, the levels of PI3K、Akt、p-Akt、mTOR and p-mTOR were increased in the model group (all <0.01). Compared with the model group, the levels of PI3K、Akt、p-Akt、mTOR and p-mTOR were reduced in the moxibustion group, the rapamycin group and the combination group (all <0.01). Compared with the moxibustion group, the levels of PI3K、Akt、and p-mTOR were increased in the rapamycin group and the levels of PI3K、Akt、p-Akt、mTOR and p-mTOR were increased in the combination group (all <0.01). Compared with the rapamycin group, the levels of PI3K、Akt、p-Akt、mTOR and p-mTOR were increased in the combination group (<0.01).@*CONCLUSION@#Moxibustion at acupoints of governor vessel can enhance the autophagy process on Aβ in brain of the APP/PS1 double-transgenic AD mice, which may be associated with its effects on inhibiting the abnormal activation of PI3K/Akt/mTOR signaling pathway.
Asunto(s)
Animales , Masculino , Ratones , Enfermedad de Alzheimer , Péptidos beta-Amiloides , Autofagia , Modelos Animales de Enfermedad , Hipocampo , Ratones Endogámicos C57BL , Ratones Transgénicos , Moxibustión , Fosfatidilinositol 3-Quinasas , Proteínas Proto-Oncogénicas c-akt , Transducción de Señal , Serina-Treonina Quinasas TORRESUMEN
<p><b>OBJECTIVE</b>We investigated the role of endoplasmic reticulum stress (ERS) in silica-induced apoptosis in alveolar macrophages in vitro.</p><p><b>METHODS</b>RAW264.7 cells were incubated with 200 μg/mL silica for different time periods. Cell viability was assayed by the MTT assay. Cell apoptosis was evaluated by DAPI staining, flow cytometry analysis, and Western blot analysis of caspase-3. Morphological changes in the endoplasmic reticulum were observed by transmission electron microscopy. The expression of ERS markers binding protein (BiP) and CCAAT-enhancer-binding protein homologous protein (CHOP) was examined by Western blotting and real-time PCR. As an inhibitor of ERS, 4-phenylbutyric acid (4-PBA) was used in the experiments.</p><p><b>RESULTS</b>Silica exposure induced nuclear condensation and caspase-3 expression in RAW264.7 cells. The number of apoptotic cells increased after silica exposure in a time-dependent manner. Silica treatment induced expansion of the endoplasmic reticulum. In addition, the expression of BiP and CHOP increased in silica-stimulated cells. Furthermore, 4-PBA treatment inhibited silica-induced endoplasmic reticulum expansion and the expression of BiP and CHOP. Moreover, 4-PBA treatment attenuated nuclear condensation, reduced apoptotic cells, and downregulated caspase-3 expression in silica-stimulated cells.</p><p><b>CONCLUSION</b>Silica-induced ERS is involved in the apoptosis of alveolar macrophages.</p>
Asunto(s)
Animales , Ratones , Apoptosis , Butilaminas , Supervivencia Celular , Estrés del Retículo Endoplásmico , Fisiología , Dióxido de Silicio , ToxicidadRESUMEN
<p><b>OBJECTIVE</b>To observe the efficacy on primary osteoporosis treated with spreading moxibustion for warming yang and activating blood circulation so as to provide the effective clinical therapeutic methods for osteoporosis.</p><p><b>METHODS</b>Sixty cases of primary osteoporosis were randomized into a spreading moxibustion group (30 cases) and a calcium tablet group (30 cases). In the calcium tablet group, caltrate was prescribed for oral administration, 600 mg per day. In the spreading moxibustion group, on the basis of the treatment as the calcium tablet group, the spreading moxibustion was applied at Dazhui (GV 14) to Yaoshu (GV 2) for warming yang and activating blood circulation. The duration of treatment was 12 weeks. Visual analogue scale (VAS) score, TCM clinical symptom score and bone mineral density (BMD) were observed and compared before and after treatment in the patients between the two groups.</p><p><b>RESULTS</b>VAS scores were reduced apparently after treatment in the two groups (both P < 0.01) and the results in the spreading moxibustion group were obviously superior to that in the calcium tablet group (2.36 +/- 0.43 vs 4.52 +/- 0.35, P < 0.01). BMD were all increased in the two groups (P < 0.05, P < 0.01) and the results in the spreading moxibustion group were superior to those in the calcium tablet group (both P < 0.05). The total clinical effective rate was 86.67% (26/30) in the spreading moxibustion group, apparently better than 63.33% (19/30) in the calcium tablet group (P < 0.05). TCM clinical symptom scores after treatment were all reduced apparently in the two groups (both P < 0.01), and the result in the spreading moxibustion group was obviously superior to that in the calcium tablet group (4.72 +/- 1.90 vs 6.82 +/- 2.30, P < 0.01). The total effective rate of TCM symptoms was 93.33% (28/30) in the spreading moxibustion group, apparently better than 70.00% (21/30) in the calcium tablet group (P < 0.05).</p><p><b>CONCLUSION</b>The combined therapy of spreading moxibustion for warming yang and activating blood circulation and the oral administration of caltrate apparently relieves pain and TCM clinical symptoms, improves BMD in the patients of osteoporosis and achieves definite clinical efficacy in the patients of osteoporosis.</p>
Asunto(s)
Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Circulación Sanguínea , Densidad Ósea , Moxibustión , Osteoporosis , Terapéutica , Deficiencia Yang , TerapéuticaRESUMEN
<p><b>OBJECTIVE</b>To observe clinical curative effect of cake-separated moxibustion on impaired glucose regulation (IGR) and explore its action mechanism.</p><p><b>METHODS</b>Sixty cases were randomly divided into a simple lifestyle intervention group (control group) and a cake-separated moxibustion combined with lifestyle intervention group (observation group), 30 cases in each one. The control group was treated with lifestyle intervention. Based on lifestyle intervention, cake-separated moxibustion at Pishu (BL 20), Weishu (BL 21) and Yishu (EX-B 3) was applied to the observation group. Fast plasma glucose (FPG), two hours plasma glucose after oral glucose tolerance test (OGTT2hPG), fasting insulin (FINS), homa insulin resistance index (HOMA-IR), blood lipid, body mass index (BMI) and waist circumference (WC) were observed in the two groups before and after treatment.</p><p><b>RESULTS</b>After treatment, the OGTT2hPG and FPG were both decreased significantly (both P<0.05) in the two groups, compared between the two groups, the differences of FPG [(0.41 +/- 0.42) mmol/L vs (0.05 +/- 0.08)mmol/L] and OGTT2hPG [(0.85 +/- 0.53)mmol/L vs (0.17 +/- 0.19)mmol/L] were both statistically significant. There were no significant changes in FINS, HOMA-IR, blood lipid, BMI and WC in the control group before and after treatment (all P>0.05), but FINS, HOMA-IR levels, triglycerides (TG), total cholest-erol (TC), low density lipoprotein (LDL-C), BMI and WC in the observation group were decreased obviously after treatment (all P<0.05), which had statistical differences between the two groups (all P<0.05).</p><p><b>CONCLUSION</b>The cake-separated moxibustion combined with lifestyle intervention can obviously control blood glucose levels, improve insulin resistance and blood lipid levels, decrease BMI and WC.</p>
Asunto(s)
Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Glucosa , Metabolismo , Intolerancia a la Glucosa , Metabolismo , Terapéutica , Insulina , Moxibustión , Circunferencia de la CinturaRESUMEN
Objective To explore the relationship between fluconazole resistance and expression of multidrug resistant protein genes,including CDR1,CDR2,MDRI.Methods The total RNA was extracted from fluconazole-resistant and -susceptible Candida albicans isolates,and cDNA was synthesized.The expression of CDR1,CDR2 and MDRl genes was then detected by quantitative real-time PCR.The?CT (threshold cycle) value was obtained by subtracting the CT value of 18S rRNA from that of the targeted gene.Results The?CT value of CDR2 was significantly lower in fluconazole-resistant isolates than in fluconazole- susceptible isolates (7.52?2.53 vs.9.28?3.15,t=2.367,P