Elevated Tribbles homolog 2-specific antibody levels in narcolepsy patients.
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SUBMITTER: Cvetkovic-Lopes V
PROVIDER: S-EPMC2827962 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Study objectivesNarcolepsy is a sleep disorder characterized by excessive daytime sleepiness and cataplexy. The association with human leukocyte antigen (HLA)-DQB1*0602 and T-cell receptor alpha locus suggests that autoimmunity plays a role in narcolepsy. A recent study reported an increased prevalence of autoantibodies against Tribbles homolog 2 (TRIB2) in patients with narcolepsy. To replicate this finding, we examined anti-TRIB2 autoantibodies in Japanese patients with narcolepsy.DesignWe examined anti-TRIB2 autoantibodies against a full-length [35S]-labeled TRIB2 antigen in Japanese patients with narcolepsy-cataplexy (n = 88), narcolepsy without cataplexy (n = 18), and idiopathic hypersomnia with long sleep time (n = 11). The results were compared to Japanese healthy controls (n = 87). Thirty-seven healthy control subjects were positive for HLA-DRB1*1501-DQB1*0602. We also examined autoantibodies against another Tribbles homolog, TRIB3, as an experimental control.Measurements and resultsAutoantibodies against TRIB2 were found in 26.1% of patients with narcolepsy-cataplexy, a significantly higher prevalence than the 2.3% in healthy controls. We found that anti-TRIB3 autoantibodies were rare in patients with narcolepsy and showed no association with anti-TRIB2 indices. No significant correlation was found between anti-TRIB2 positivity and clinical information.ConclusionsWe confirmed the higher prevalence and specificity of anti-TRIB2 autoantibodies in Japanese patients with narcolepsy-cataplexy. This suggests a subgroup within narcolepsy-cataplexy might be affected by an anti-TRIB2 autoantibody-mediated autoimmune mechanism.
| S-EPMC2894429 | biostudies-literature
Project description:Study objectiveRecent studies have found increased autoantibodies against Tribbles homolog 2 (anti-TRIB2) and anti-streptolysin O (ASO) in narcolepsy. In this study, we replicated this finding with a primary focus on recent onset cases.Participants and methodsParticipants included (1) 90 cases with cataplexy, (2) 57 cases without cataplexy, and (3) 156 age-sex matched controls, including 73 human leukocyte antigen (HLA)-DQB1*0602 allele carriers. A radioligand binding assay was used to detect anti-TRIB2 antibodies.ResultsAnti-TRIB2 antibodies were prevalent in HLA-DQB1*0602 positive cases with cataplexy (25.0% of 76) and rare in cases without cataplexy (3.5% of 57, OR = 9.2, 95% CI = 2.5 - 33.5, P = 6.0 x 10(-4)) or controls (4.5% of 156, OR = 7.1, 95% CI = 3.1 - 16.2, P = 9.3 x 10(-6)). Anti-TRIB2 positivity in controls was not associated with DQB1*0602. In DQB1*0602 narcolepsy-cataplexy cases, the presence of anti-TRIB2 was associated with short disease duration (2.3 years from cataplexy onset), with 41.0% positive in this group (OR = 7.4 versus cases with onset > 2.3 years, 95% CI = 1.9- 28.5, P = 9.0 x 10(-4)). Anti-TRIB2 positivity in 39 DQB1*0602 positive recent onset cases was associated with increased ASO antibody (> 200 IU) (OR = 6.2, 95% CI = 1.6 - 24.6, P = 0.01), but did not correlate with age, gender, or body mass index.ConclusionAnti-TRIB2 autoantibodies are strongly associated with narcolepsy close to cataplexy onset (< or = 2.3 years). Anti-TRIB2 was rarely found in cases without cataplexy or with distant onset.
| S-EPMC2894428 | biostudies-literature
Project description:BackgroundTribbles Homolog 3 (TRIB3) is a member of the pseudokinase family of tribbles and acts as an adaptor protein to regulate different cellular processes. Upregulation of TRIB3 expression was shown either as a favorable or an adverse prognostic factor in various adult malignancies. However, TRIB3 expression has not been examined in pediatric cancers. Neuroblastoma is the most common malignant solid tumor of childhood, which affects mostly children under 5 years old. Risk stratification of patients defined by International Neuroblastoma Risk Group was used to determine prognosis and treatment of the disease. This study aimed to examine the relationship between TRIB3 protein expression levels and clinicopathological features and survival of patients.MethodsTRIB3 protein expression was analyzed using immunohistochemical staining on formalin-fixed paraffin-embedded tissue samples of neuroblastoma patients (n = 56). Survival analyses were performed with Kaplan-Meier method and log-rank tests. Association between TRIB3 expression and clinicopathological characteristics were analyzed with Spearman's correlation.ResultsOf the patients, 32.1% were in the low-risk group, 21.4% in the medium-risk group, and 46.4% in the high-risk group. Survival analysis was performed in the entire neuroblastoma patient group and sub-risk groups of neuroblastoma patients. In the entire patient group, there was no significant difference in overall survival (P = .202) and event-free survival (P = .172) between TRIB3-positive and -negative patients. However, when survival analyses were performed in each risk group, TRIB3 expression was significantly associated with higher overall survival (P = .034) and event-free survival (P = .032) in low-risk group neuroblastoma patients. Nevertheless, no association was found between TRIB3 expression and overall survival (P = .799) and event-free survival (P = .448) in high-risk neuroblastoma patients. Furthermore, a significant correlation was identified between 1p36 loss-of-heterozygosity and TRIB3 expression (P = .030). However, TRIB3 expression did not correlate with other clinicopathological features.ConclusionTRIB3 expression is a potential predictive biomarker for low-risk neuroblastoma patients.
| S-EPMC10515557 | biostudies-literature
Project description:With the routine use of effective severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines, the number of life-threatening coronavirus disease 2019 (COVID-19) courses have largely been reduced. However, multiple COVID-19 convalescents, even after asymptomatic to moderate disease, suffer from post-COVID syndrome, with relevant limitations in daily life. The pathophysiologic mechanisms of post-COVID syndrome are still elusive, with dysregulation of the immune system suggested as a central mechanism. Here, we assessed COVID-19 post-infectious symptoms (5-6 months after PCR-confirmed acute infection) together with the humoral immune response against SARS-CoV-2 in non-hospitalized COVID-19 convalescents, early (5-6 weeks) and late (5-6 months) after their first positive SARS-CoV-2 PCR result. Convalescents reporting several post-infectious symptoms (>3) showed higher anti-spike and anti-nucleocapsid antibody levels 5-6 weeks after PCR-confirmed infection with the latter remained increased 5-6 months after positive PCR. Likewise, a higher post-infectious symptom score was associated with increased antibody levels. Of note, convalescents displaying neuro-psychiatric symptoms such as restlessness, palpitations, irritability, and headache, as well as general symptoms such as fatigue/reduced power had higher SARS-CoV-2-specific antibody levels compared with asymptomatic cases. The increased humoral immune response in convalescents with post-COVID syndrome might be useful for the detection of individuals with an increased risk for post-COVID syndrome.
| S-EPMC10051370 | biostudies-literature
Project description:BackgroundThe incidence of tuberculosis (TB) is high among human immunodeficiency virus (HIV) infected Ugandans. Recent evidence suggests that Chronic Pulmonary Aspergillosis and Aspergillus sensitisation might be responsible for significant mortality in patients treated for tuberculosis in Uganda.MethodsWe retrieved and tested paired serum aliquots for 101 HIV-TB co-infected patients at the beginning and week 24 of TB treatment. We tested samples for Aspergillus-specific immunoglobulin G (IgG) and immunoglobulin E (IgE) using ImmunoCAP®; and Aspergillus-specific IgG and total serum IgE using Immulite® immunoassays. We compared antibody levels between baseline and week 24, relating them to selected baseline characteristics.Results10% of the patients had elevated Aspergillus-specific IgE (Aspergillus sensitization) and Aspergillus-specific IgG antibodies were elevated in 9% of the patients at the end of TB treatment. There was a significant fall in the Aspergillus-specific IgG antibody levels between baseline and week 24 (P = 0.02). Patients with cluster of differentiation 4 (CD4) T-cell count <100 cells/μl and those who were not on anti-retroviral therapy at baseline had more elevated Aspergillus-specific IgG antibodies (P = 0.01, P = 0.03). The ImmunoCAP® Aspergillus-specific IgG antibody titres were higher at week 24 than baseline with more positives at week 24; even though the difference in means was small. However, this difference was statistically significant (P = 0.02). Pulmonary infiltrates were the commonest x-ray abnormality and only 5% of the patients had pulmonary cavities on chest x-ray at week 24.ConclusionThese results suggest that Aspergillus infection may complicate active pulmonary TB and further studies including fungal culture and thoracic imaging may now be indicated to measure the prevalence of pulmonary aspergillosis complicating tuberculosis.Trial registrationThe SOUTH trial was registered prospectively. ClinicalTrials.gov Identifier: NCT01782950 ; Registration date: 4th February 2013; Last verified: 13th April 2015.
| S-EPMC5699185 | biostudies-literature
Project description:BACKGROUND:Narcolepsy is a sleep disorder characterized by excessive daytime sleepiness, cataplexy, and REM sleep abnormalities. A genome-wide association study identified a novel narcolepsy-related single nucleotide polymorphism (SNP), rs5770917, which is located adjacent to CPT1B (carnitine palmitoyltransferase 1B). In this study, we analyzed the CPT1B expression level and measured the carnitine fractions in blood samples obtained from narcolepsy patients and control subjects to test the hypothesis that fatty acid ?-oxidation is altered in narcolepsy. METHODOLOGY AND RESULTS:We measured CPT1B mRNA expression in white blood cells of 38 narcolepsy patients and 56 healthy control subjects. The serum carnitine fractions (total carnitine, free carnitine, and acylcarnitine) were measured in the 38 narcolepsy patients and in 30 of 56 control subjects. Stepwise multiple regression analysis revealed that the risk allele (C) for SNP rs5770917 was significantly associated with decreased CPT1B mRNA expression (P = 1.0 × 10(-9)), and the CPT1B expression was higher in the narcolepsy patients than in the controls (P = 0.005). The acylcarnitine levels were abnormally low in 21% of the narcolepsy patients while those of all the controls were within the normal range. Stepwise multiple regression analysis using the dichotomous variable for acylcarnitine (normal or abnormal) as an objective variable revealed that the diagnosis of narcolepsy but not CPT1B expression level and BMI was associated with abnormally low acylcarnitine levels (P = 0.006). CONCLUSIONS:Our results indicate that multiple factors are involved in the regulation of serum acylcarnitine levels. Abnormally low levels of acylcarnitine observed in narcolepsy suggest dysfunctional fatty acid ?-oxidation pathway.
| S-EPMC3041711 | biostudies-literature
Project description:Insulin signaling plays a physiological role in traditional insulin target tissues controlling glucose homeostasis as well as in pancreatic ?-cells and in the endothelium. Insulin signaling abnormalities may, therefore, be pathogenic for insulin resistance, impaired insulin secretion, endothelial dysfunction, and eventually, type 2 diabetes mellitus (T2DM) and cardiovascular disease. Tribbles homolog 3 (TRIB3) is a 45-kDa pseudokinase binding to and inhibiting Akt, a key mediator of insulin signaling. Akt-mediated effects of TRIB3 in the liver, pancreatic ?-cells, and skeletal muscle result in impaired glucose homeostasis. TRIB3 effects are also modulated by its direct interaction with other signaling molecules. In humans, TRIB3 overactivity, due to TRIB3 overexpression or to Q84R genetic polymorphism, with R84 being a gain-of-function variant, may be involved in shaping the risk of insulin resistance, T2DM, and cardiovascular disease. TRIB3 overexpression has been observed in the liver, adipose tissue, skeletal muscle, and pancreatic ?-cells of individuals with insulin resistance and/or T2DM. The R84 variant has also proved to be associated with insulin resistance, T2DM, and cardiovascular disease. TRIB3 direct effects on the endothelium might also play a role in increasing the risk of atherosclerosis, as indicated by studies on human endothelial cells carrying the R84 variant that are dysfunctional in terms of Akt activation, NO production, and other proatherogenic changes. In conclusion, studies on TRIB3 have unraveled new molecular mechanisms underlying metabolic and cardiovascular abnormalities. Additional investigations are needed to verify whether such acquired knowledge will be relevant for improving care delivery to patients with metabolic and cardiovascular alterations.
| S-EPMC3410226 | biostudies-literature
Project description:Tribbles homolog 2 (Trib2) was identified as a downregulated transcript in leukemic cells undergoing growth arrest. To investigate the effects of Trib2 in hematopoietic progenitors, mice were reconstituted with hematopoietic stem cells retrovirally expressing Trib2. Trib2-transduced bone marrow cells exhibited a growth advantage ex vivo and readily established factor-dependent cell lines. In vivo, Trib2-reconstituted mice uniformly developed fatal transplantable acute myelogenous leukemia (AML). In mechanistic studies, we found that Trib2 associated with and inhibited C/EBPalpha. Furthermore, Trib2 expression was elevated in a subset of human AML patient samples. Together, our data identify Trib2 as an oncogene that induces AML through a mechanism involving inactivation of C/EBPalpha.
| S-EPMC2839500 | biostudies-literature
Project description:An increase in hepatic triglyceride (TG) contents usually results in non-alcoholic fatty liver disease (NAFLD) and related metabolic diseases. However, the mechanisms underlying perturbations of hepatic TG homeostasis remain largely unknown. Here, we showed that MicroRNA-124 was up-regulated in the livers of C57BL/6 mice fed a short-term high-fat-diet (HFD). Adenoviral overexpression of miR-124 in C57BL/6 mice led to accumulation of excessive triglycerides and up-regulation of lipogenic genes in the liver. We further identified tribbles homolog 3 (TRB3) as a direct target of miR-124. AKT signaling, which is negatively regulated by TRB3, was enhanced by miR-124 overexpression. Moreover, restoration of TRB3 expression markedly abolished the effect of miR-124 on hepatic TG metabolism. Therefore, our findings revealed that miR-124 played a role in mediating high-fat-diet induced TG accumulation in the liver.
| S-EPMC5109039 | biostudies-literature
Project description:BackgroundThe association of rs17321515 single nucleotide polymorphism (SNP) near TRIB1 gene and serum lipid profiles has never been studied in the Chinese population. Therefore, the present study was undertaken to detect the association of rs17321515 SNP and several environmental factors on serum lipid levels in the Mulao and Han populations.MethodsA total of 639 unrelated subjects of Mulao nationality and 644 participants of Han nationality were randomly selected from our previous stratified randomized cluster samples. Genotypes of the TRIB1 rs17321515 A>G SNP were determined via polymerase chain reaction and restriction fragment length polymorphism, and then confirmed by direct sequencing.ResultsSerum apolipoprotein (Apo) B levels were higher in Mulao than in Han (P < 0.05). There were no differences in the genotypic and allelic frequencies between the two ethnic groups (P > 0.05). High- and low-density lipoprotein cholesterol (HDL-C and LDL-C) levels in Han were different among the genotypes (P < 0.05 for each), the subjects with AG/GG genotypes had higher HDL-C and LDL-C levels than the subjects with AA genotype. Total cholesterol (TC), HDL-C, LDL-C, ApoA1 and ApoB levels in Han males were different among the genotypes (P < 0.05-0.001), the G carriers had higher TC, HDL-C, LDL-C, ApoA1 and ApoB levels than the G noncarriers. HDL-C levels in Mulao males were different among the genotypes (P < 0.05), the G carriers had lower HDL-C levels than the G noncarriers. Serum HDL-C and LDL-C levels in both ethnic groups and TG levels in Han were correlated with the genotypes or alleles (P < 0.05-0.01). TG and HDL-C levels in Mulao males and TG, HDL-C, LDL-C and ApoA1 levels in Han males were correlated with genotypes or alleles (P < 0.05-0.001). TG and ApoA1 levels in Han females were associated with genotypes (P < 0.05 for each). Serum lipid parameters were also associated with several environmental factors in both ethnic groups.ConclusionsThe associations of TRIB1 rs17321515 SNP and serum lipid levels are different between the Mulao and Han populations. These discrepancies might partly result from different TRIB1 gene-environmental interactions in both ethnic groups.
| S-EPMC3281799 | biostudies-literature