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BACKGROUND AND PURPOSE: Vitamin D is considered to play a role in multiple sclerosis (MS) etiopathogenesis. A polymorphism in the CYP24A1 gene, rs2762943, was recently identified that was associated with an increased MS risk. CYP24A1 encodes a protein involved in the catabolism of the active form of vitamin D. The immunological effects of carrying the rs2762943 risk allele were investigated, as well as its role as genetic modifier. METHODS: Serum levels of 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D (1,25(OH)2 D) were measured in a cohort of 167 MS patients. In a subgroup of patients, expression levels of major histocompatibility complex class II and co-stimulatory molecules were determined by flow cytometry, and serum levels of pro-inflammatory (interferon gamma, granulocyte macrophage colony-stimulating factor, C-X-C motif chemokine ligand 13) and anti-inflammatory (interleukin 10) cytokines and neurofilament light chain were measured by single-molecule array assays. The effect of the rs2762943 polymorphism on disease activity and disability measures was evaluated in 340 MS patients. RESULTS: Compared to non-carriers, carriers of the rs2762943 risk allele were characterized by reduced levels of 1,25(OH)2 D (p = 0.0001) and elevated levels of interferon gamma (p = 0.03) and granulocyte macrophage colony-stimulating factor (p = 0.008), whereas no significant differences were observed for the other markers. The presence of the rs2762943 risk allele had no significant impact on disease activity and disability outcomes during follow-up. However, risk allele carriers were younger at disease onset (p = 0.04). CONCLUSIONS: These findings suggest that the CYP24A1 rs2762943 polymorphism plays a more important role in MS susceptibility than in disease prognosis and is associated with lower 1,25(OH)2 D levels and a heightened pro-inflammatory environment in MS patients.
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Esclerosis Múltiple , Humanos , Vitamina D3 24-Hidroxilasa/genética , Vitamina D3 24-Hidroxilasa/metabolismo , Esclerosis Múltiple/genética , Interferón gamma , Factor Estimulante de Colonias de Macrófagos , Vitamina D , VitaminasRESUMEN
BACKGROUND: Primary hypophosphatemic syndromes are a heterogeneous group of rare diseases. In recent years, fibroblast growth factor 23 (FGF23) has been postulated as a useful tool for differential diagnosis of hypophosphatemic rickets characterized by impaired renal phosphate reabsorption. This study aimed to investigate the utility of FGF23 to discriminate between X-linked hypophosphatemic rickets (XLH), an FGF23-driven disease, from other causes of renal phosphate wasting such as Fanconi syndrome (FS), a generalized dysfunction of the proximal tubule unrelated to FGF23. METHODS: Circulating levels of intact FGF23 (iFGF23) were measured in nine children with XLH receiving conventional therapy (six girls, mean ± SD age 10.8 ± 6.7 years) and nine children with secondary FS (four girls, mean ± SD age 9.9 ± 5.2 years), using an automated chemiluminescent immunoassay. Phosphate, calcium, creatinine, estimated glomerular filtration rate (eGFR), intact parathormone (iPTH), and urinary parameters were evaluated simultaneously. Maximum renal tubular threshold for phosphate reabsorption (TmP/GFR) was also estimated. RESULTS: Plasma iFGF23 concentrations in patients with XLH were significantly higher than those in the SF group: 146.2 ± 69.2 ng/L vs. 29.5 ± 15.0 ng/L (p < 0.001). Remarkably, we did not observe an overlap between XLH and FS patients. Significant hypophosphatemia (2.55 ± 0.50 mg/dL) and secondary hyperparathyroidism (iPTH 109.4 ± 58.1 ng/mL) were present in XLH patients, while FS patients showed modest hypophosphatemia (3.97 ± 0.68 mg/dL), higher TmP/GFR compared with XLH, lower eGFR and hypercalciuria. CONCLUSIONS: This study supports the value of measuring FGF23 levels as a useful tool to exclude XLH in patients with increased phosphate wasting of kidney origin. Graphical Abstract.
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Raquitismo Hipofosfatémico Familiar , Factor-23 de Crecimiento de Fibroblastos/sangre , Hipofosfatemia , Adolescente , Niño , Preescolar , Diagnóstico Diferencial , Raquitismo Hipofosfatémico Familiar/diagnóstico , Femenino , Humanos , Hipofosfatemia/diagnóstico , Hipofosfatemia/etiología , Masculino , Fosfatos , Timidina MonofosfatoRESUMEN
BACKGROUND: α1-Antitrypsin deficiency (AATD) is an autosomal codominant disorder associated with a high risk of developing lung and liver disease. The most common deficient alleles are known as Z and S. However, another deficient variant, called Mmalton, which causes a deficiency similar to variant Z, is considered to be the second cause of severe AATD in Spain. Nevertheless, the Mmalton allele is not recognizable by usual diagnostic techniques and therefore, its real prevalence is underestimated. We describe a rapid real-time PCR and melting curves assay designed for the detection of Mmalton AATD. METHODS: We tested the applicability of this new technique for the identification of the Mmalton allele in AATD screening using whole blood, dried blood spot (DBS) and serum samples. Mmalton heterozygote and homozygote samples and samples without this allele were included in the study. RESULTS: This new assay is able to detect homozygous and heterozygous genotypes in the same reaction and in a single step, giving matching results with those obtained by SERPINA1 gene sequencing. CONCLUSIONS: This technology is optimal for working with small amounts of DNA, such as in DBS and even with residual DNA present in serum samples, allowing improvement in routine algorithms of AATD diagnosis or large-scale screening. This method will be useful for obtaining more in depth knowledge of the real incidence of the Mmalton variant.
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ADN/sangre , Reacción en Cadena en Tiempo Real de la Polimerasa , alfa 1-Antitripsina/genética , Algoritmos , Alelos , Secuencia de Bases , ADN/química , ADN/aislamiento & purificación , Pruebas con Sangre Seca , Transferencia Resonante de Energía de Fluorescencia , Colorantes Fluorescentes/química , Genotipo , Heterocigoto , Humanos , Análisis de Secuencia de ADN , Temperatura de TransiciónRESUMEN
We hypothesized that the analysis of mRNA level and activity of key enzymes in amino acid and carbohydrate metabolism in a feeding/fasting/refeeding setting could improve our understanding of how a carnivorous fish, like the European seabass (Dicentrarchus labrax), responds to changes in dietary intake at the hepatic level. To this end cDNA fragments encoding genes for cytosolic and mitochondrial alanine aminotransferase (cALT; mALT), pyruvate kinase (PK), glucose 6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconate dehydrogenase (6PGDH) were cloned and sequenced. Measurement of mRNA levels through quantitative real-time PCR performed in livers of fasted seabass revealed a significant increase in cALT (8.5-fold induction) while promoting a drastic 45-fold down-regulation of PK in relation to the levels found in fed seabass. These observations were corroborated by enzyme activity meaning that during food deprivation an increase in the capacity of pyruvate generation happened via alanine to offset the reduction in pyruvate derived via glycolysis. After a 3-day refeeding period cALT returned to control levels while PK was not able to rebound. No alterations were detected in the expression levels of G6PDH while 6PGDH was revealed to be more sensitive specially to fasting, as confirmed by a significant 5.7-fold decrease in mRNA levels with no recovery after refeeding. Our results indicate that in early stages of refeeding, the liver prioritized the restoration of systemic normoglycemia and replenishment of hepatic glycogen. In a later stage, once regular feeding is re-established, dietary fuel may then be channeled to glycolysis and de novo lipogenesis.
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Lubina/fisiología , Ingestión de Alimentos/fisiología , Ayuno/fisiología , Proteínas de Peces/metabolismo , Regulación Enzimológica de la Expresión Génica , Hígado/enzimología , Metabolismo Secundario , Animales , Acuicultura , Citosol/enzimología , Citosol/metabolismo , Proteínas de Peces/genética , Lipogénesis , Hígado/metabolismo , Mitocondrias Hepáticas/enzimología , Mitocondrias Hepáticas/metabolismo , Vía de Pentosa Fosfato , Portugal , ARN Mensajero/metabolismoRESUMEN
BACKGROUND AND AIMS: Acute ischemic stroke (AIS) outcome prognostication remains challenging despite available prognostic models. We investigated whether a biomarker panel improves the predictive performance of established prognostic scores. METHODS: We investigated the improvement in discrimination, calibration, and overall performance by adding five biomarkers (procalcitonin, copeptin, cortisol, mid-regional pro-atrial natriuretic peptide (MR-proANP), and N-terminal pro-B-type natriuretic peptide (NT-proBNP)) to the Acute Stroke Registry and Analysis of Lausanne (ASTRAL) and age/NIHSS scores using data from two prospective cohort studies (SICFAIL, PREDICT) and one clinical trial (STRAWINSKI). Poor outcome was defined as mRS > 2 at 12 (SICFAIL, derivation dataset) or 3 months (PREDICT/STRAWINSKI, pooled external validation dataset). RESULTS: Among 412 SICFAIL participants (median age 70 years, quartiles 59-78; 63% male; median NIHSS score 3, quartiles 1-5), 29% had a poor outcome. Area under the curve of the ASTRAL and age/NIHSS were 0.76 (95% CI 0.71-0.81) and 0.77 (95% CI 0.73-0.82), respectively. Copeptin (0.79, 95% CI 0.74-0.84), NT-proBNP (0.80, 95% CI 0.76-0.84), and MR-proANP (0.79, 95% CI 0.75-0.84) significantly improved ASTRAL score's discrimination, calibration, and overall performance. Copeptin improved age/NIHSS model's discrimination, copeptin, MR-proANP, and NT-proBNP improved its calibration and overall performance. In the validation dataset (450 patients, median age 73 years, quartiles 66-81; 54% men; median NIHSS score 8, quartiles 3-14), copeptin was independently associated with various definitions of poor outcome and also mortality. Copeptin did not increase model's discrimination but it did improve calibration and overall model performance. DISCUSSION: Copeptin, NT-proBNP, and MR-proANP improved modest but consistently the predictive performance of established prognostic scores in patients with mild AIS. Copeptin was most consistently associated with poor outcome in patients with moderate to severe AIS, although its added prognostic value was less obvious.
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Genetic tests have led to the discovery of many novel genetic variants related to growth failure, but the clinical significance of some results is not always easy to establish. The aim of this report is to describe both clinical phenotype and genetic characteristics in an adult patient with short stature associated with a homozygous variant in disintegrin and metalloproteinase with thrombospondin motifs type 17 gene (ADAMTS17) combined with a homozygous variant in the GH secretagogue receptor (GHS-R). The index case had severe short stature (SS) (-3.0 SD), small hands and feet, associated with eye disturbances. Genetic tests revealed homozygous compounds for ADAMTS17 responsible for Weill-Marchesani-like syndrome but a homozygous variant in GHS-R was also detected. Dynamic stimulation with an insulin tolerance test showed a normal elevation of GH, while the GH response to macimorelin stimulus was totally flattened. We show the implication of the GHS-R variant and review the molecular mechanisms of both entities. These results allowed us to better interpret the phenotypic spectrum, associated co-morbidities, its implications in dynamic tests, genetic counselling and treatment options not only to the index case but also for her relatives.
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BACKGROUND: Gestational hypothyroidism has been shown to be associated with adverse pregnancy outcomes as well as adverse outcomes for the child. Thyroid hormones concentrations change in gestation, especially within the first trimester, so the results of thyroid function test often are outside non-pregnant reference ranges. The objective of this study was to establish the first trimester reference ranges for thyroid stimulating hormone (TSH) and free thyroxine (FT4) for pregnant women in Barcelona (Spain). METHODS: It was a prospective study in which 673 women were recruited during their first trimester of gestation (8-13 weeks). Serum TSH, FT4 and antithyroid peroxidase antibodies (TPOAb) were measured with Atellica® IM 1600 (Siemens Healthineers). After excluding 418 women, the reference ranges for TSH and FT4 were calculated by the 2.5th and 97.5th percentiles. Potential variables examined in this study were age, body mass index (BMI), ethnicity, iodine supplementation and smoking habit. RESULTS: The reference ranges established on the Atellica® IM 1600 for the first trimester pregnancy in our population were 0.111 to 4.291 mIU/L for TSH and 11.45 to 17.76 pmol/L for FT4. No significant differences were found in thyroid hormones concentrations regarding maternal age (≤30 years vs >30 years) (p = .117), iodine supplementation (p = .683) and smoking habit (p = .363). The prevalence of TPOAb was estimated at 10.0%. CONCLUSIONS: We found that in our local population, the optimal TSH upper reference limit in the first trimester of gestation was 4.3 mIU/L, similar to that proposed by de ATA-2017 guideline (4.0 mIU/L).
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PURPOSE: Changes in the myocardial extracellular matrix (ECM) identified using T1 mapping cardiovascular magnetic resonance (CMR) have been only reported in obese adults, but with opposite conclusions. The objectives are to assess the composition of the myocardial ECM in an obese pediatric population without type 2 diabetes by quantifying native T1 time, and to quantify the pericardial fat index (PFI) and their relationship with cardiovascular risk factors. METHODS: Observational case-control research of 25 morbidly obese adolescents and 13 normal-weight adolescents. Native T1 and T2 times (ms), left ventricular (LV) geometry and function, PFI (g/ht3) and hepatic fat fraction (HFF, %) were calculated by 1.5-T CMR. RESULTS: No differences were noticed in native T1 between obese and non-obese adolescents (1000.0 vs. 990.5 ms, p0.73), despite showing higher LV mass values (28.3 vs. 22.9 g/ht3, p0.01). However, the T1 mapping values were significantly higher in females (1012.7 vs. 980.7 ms, p < 0.01) while in males, native T1 was better correlated with obesity parameters, particularly with triponderal mass index (TMI) (r = 0.51), and inflammatory cells. Similarly, the PFI was correlated with insulin resistance (r = 0.56), highly sensitive C-reactive protein (r = 0.54) and TMI (r = 0.77). CONCLUSION: Female adolescents possess myocardium peculiarities associated with higher mapping values. In males, who are commonly more exposed to future non-communicable diseases, TMI may serve as a useful predictor of native T1 and pericardial fat increases. Furthermore, HFF and PFI appear to be markers of adipose tissue infiltration closely related with hypertension, insulin resistance and inflammation.
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Diabetes Mellitus Tipo 2 , Resistencia a la Insulina , Obesidad Mórbida , Adolescente , Adulto , Niño , Femenino , Humanos , Masculino , Tejido Adiposo/diagnóstico por imagen , Imagen por Resonancia Cinemagnética , Espectroscopía de Resonancia Magnética , Miocardio/patología , Obesidad Mórbida/complicaciones , Obesidad Mórbida/patología , Pericardio/diagnóstico por imagen , Valor Predictivo de las Pruebas , Caracteres Sexuales , Función Ventricular Izquierda , Estudios de Casos y ControlesRESUMEN
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a neuroinflammatory, multifaceted chronic disorder of unknown cause. Accumulating data indicate a link between a redox imbalance, mitochondrial dysfunction, and inflammation status in ME/CFS. Coenzyme Q10 (CoQ10) and selenium as effective antioxidant and anti-inflammatory agents have shown potential clinical implications in chronic diseases; however, their therapeutic benefits in ME/CFS remain elusive. This open-label exploratory study aimed to evaluate the effectiveness of combined CoQ10 plus selenium supplementation on clinical features and circulating biomarkers in ME/CFS. Twenty-seven ME/CFS patients received an oral combination of 400 mg of CoQ10 and 200 µg of selenium daily for 8 weeks. The primary endpoint was patient-reported changes in outcome measures from baseline to 8 weeks' postintervention. Secondary endpoint included changes in circulating biomarkers from baseline to each participant. After an 8-week intervention, a significant improvement was found for overall fatigue severity (p = 0.021) and global quality of life (p = 0.002), while there was no significant effect on the sleep disturbances (p = 0.480) among participants. After 8 week's intervention, there was significantly increased total antioxidant capacity, and there were reduced lipoperoxide levels from the participants (p < 0.0001 for both). Circulating cytokine levels decreased significantly (p < 0.01 for all), but with no significant changes in the C-reactive protein, FGF21, and NT-proBNP biomarkers after supplementation. Based on these findings, we hypothesized that long-term supplementation of combined CoQ10 and selenium may indicate a potentially beneficial synergistic effect in ME/CFS. Antioxid. Redox Signal. 36, 729-739.
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Síndrome de Fatiga Crónica , Selenio , Antioxidantes/metabolismo , Antioxidantes/uso terapéutico , Biomarcadores/metabolismo , Suplementos Dietéticos , Síndrome de Fatiga Crónica/tratamiento farmacológico , Síndrome de Fatiga Crónica/metabolismo , Humanos , Inflamación/tratamiento farmacológico , Estrés Oxidativo , Calidad de Vida , Selenio/uso terapéutico , Ubiquinona/análogos & derivadosRESUMEN
BACKGROUND AND OBJECTIVE: AFRICAT is a prospective cohort study intending to develop an atrial fibrillation (AF) screening program through the combination of blood markers, rhythm detection devices, and long-term monitoring in our community. In particular, we aimed to validate the use of NT-proBNP, and identify new blood biomarkers associated with AF. Also, we aimed to compare AF detection using various wearables and long-term Holter monitoring. METHODS: 359 subjects aged 65-75 years with hypertension and diabetes were included in two phases: Phase I (n = 100) and Phase II (n = 259). AF diagnosis was performed by baseline 12-lead ECG, 4 weeks of Holter monitoring (NuuboTM), and/or medical history. An aptamer array including 1310 proteins was measured in the blood of 26 patients. Candidates were selected according to p-value, logFC and biological function to be tested in verification and validation phases. Several screening devices were tested and compared: AliveCor, Watch BP, MyDiagnostick and Fibricheck. RESULTS: AF was present in 34 subjects (9.47%). The aptamer array revealed 41 proteins with differential expression in AF individuals. TIMP-2 and ST-2 were the most promising candidates in the verification analysis, but none of them was further validated. NT-proBNP (log-transformed) (OR = 1.934; p<0.001) was the only independent biomarker to detect AF in the whole cohort. Compared to an ECG, WatchBP had the highest sensitivity (84.6%) and AUC (0.895 [0.780-1]), while MyDiagnostick showed the highest specificity (97.10%). CONCLUSION: The inclusion and monitoring of a cohort of primary care patients for AF detection, together with the testing of biomarkers and screening devices provided useful lessons about AF screening in our community. An AF screening strategy using rhythm detection devices and short monitoring periods among high-risk patients with high NT-proBNP levels could be feasible.
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Fibrilación Atrial , Biomarcadores , Electrocardiografía Ambulatoria , Humanos , Estudios Prospectivos , EspañaRESUMEN
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a chronic, disabling, and complex multisystem illness of unknown etiology. The protein fibroblast growth factor 21 (FGF21) regulates glucose homeostasis and lipid metabolism, and the protein N-terminal prohormone of brain natriuretic peptide (NT-proBNP) is strongly associated with an elevated cardiovascular risk; however, little is known about their role in ME/CFS patients. To address this gap, we explored the association between FGF21 and NT-proBNP and oxidative stress and inflammatory markers in ME/CFS. Twenty-one ME/CFS patients and 20 matched healthy controls were included in the study. Participants filled out validated self-reported questionnaires on their current health status covering demographic and clinical characteristics. Plasma showed significantly decreased total antioxidant capacity and increased lipoperoxide levels (p = 0.009 and p = 0.021, respectively) in ME/CFS. These ME/CFS patients also had significantly increased levels of inflammatory cytokines (interleukin [IL]-1ß, IL-6, IL-10, TNF-α, and C-reactive protein) (p < 0.05 for all) but not for IL-8 (p = 0.833), indicating low-grade systemic inflammation status. Circulating FGF21 and NT-proBNP levels were significantly higher (p < 0.0001 and p = 0.005, respectively) in ME/CFS patients than in healthy controls. Significantly positive correlations were found between NT-proBNP levels and IL-1ß and IL-6 (p = 0.04 and p = 0.01) in ME/CFS patients but not between FGF21 and these cytokines. In contrast, no significant correlations were found for either FGF21 or NT-proBNP in controls. These findings lead to the hypothesis that elevated FGF21 and NT-proBNP levels and the association between NT-proBNP and inflammation may be promising novel diagnostic and therapeutic targets in ME/CFS. Antioxid. Redox Signal. 34, 1420-1427.
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Biomarcadores/sangre , Síndrome de Fatiga Crónica/diagnóstico , Factores de Crecimiento de Fibroblastos/sangre , Péptido Natriurético Encefálico/sangre , Fragmentos de Péptidos/sangre , Regulación hacia Arriba , Estudios de Casos y Controles , Diagnóstico Precoz , Síndrome de Fatiga Crónica/sangre , Femenino , Humanos , Interleucina-1beta/sangre , Interleucina-6/sangre , Peróxidos Lipídicos/sangre , Masculino , Persona de Mediana Edad , Estrés Oxidativo , AutoinformeRESUMEN
INTRODUCTION: Roux-en-Y gastric bypass (RYGB) is the most common surgical procedure for morbid obesity. However, it can present serious late complications, like postprandial hyperinsulinemic hypoglycemia (PHH). Recent data suggested an increase in intestinal SGLT-1 after RYGB. However, there is no data on the inhibition of SGLT-1 to prevent PHH in patients with prior RYBG. On this basis, we aimed to evaluate (a) the effect of canagliflozin 300 mg on the response to 100 g glucose overload (oral glucose tolerance test [OGTT]); (b) the pancreatic response after intra-arterial calcium stimulation in the context of PHH after RYGB. MATERIALS AND METHODS: This is a prospective pilot study including patients (n = 21) with PHH after RYGB, matched by age and gender with healthy controls (n = 5). Basal OGTT and after 2 weeks of daily 300 mg of canagliflozin was performed in all cases. In addition, venous sampling after intra-arterial calcium stimulation of the pancreas was performed in 10 cases. RESULTS: OGTT after canagliflozin showed a significant reduction of plasma glucose levels (minute 30: 161.5 ± 36.22 vs. 215.9 ± 58.11 mg/dL; minute 60: 187.46 ± 65.88 vs. 225.9 ± 85.60 mg/dL, p < 0.01) and insulinemia (minute 30: 95.6 ± 27.31 vs. 216.35 ± 94.86 mg/dL, p = 0.03; minute 60: 120.85 ± 94.86 vs. 342.64 ± 113.32 mIU/L, p < 0.001). At minute 180, a significant reduction (85.7%) of the rate of hypoglycemia was observed after treatment with canagliflozin (p < 0.00001). All cases presented normal pancreatic response after intra-arterial calcium administration. CONCLUSION: Canagliflozin (300 mg) significantly decreased glucose absorption and prevented PHH after 100 g OGTT in patients with RYGB. Our results suggest that canagliflozin could be a new therapeutic option for patients that present PHH after RYGB.
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Derivación Gástrica , Hipoglucemia , Obesidad Mórbida , Glucemia , Canagliflozina/efectos adversos , Derivación Gástrica/efectos adversos , Humanos , Proyectos Piloto , Estudios ProspectivosRESUMEN
Objectives: The strain the SARS-COV-2 pandemic is putting on hospitals requires that predictive values are identified for a rapid triage and management of patients at a higher risk of developing severe COVID-19. We developed and validated a prognostic model of COVID-19 severity. Methods: A descriptive, comparative study of patients with positive vs. negative PCR-RT for SARS-COV-2 and of patients who developed moderate vs. severe COVID-19 was conducted. The model was built based on analytical and demographic data and comorbidities of patients seen in an Emergency Department with symptoms consistent with COVID-19. A logistic regression model was designed from data of the COVID-19-positive cohort. Results: The sample was composed of 410 COVID-positive patients (303 with moderate disease and 107 with severe disease) and 81 COVID-negative patients. The predictive variables identified included lactate dehydrogenase, C-reactive protein, total proteins, urea, and platelets. Internal calibration showed an area under the ROC curve (AUC) of 0.88 (CI 95%: 0.85-0.92), with a rate of correct classifications of 85.2% for a cut-off value of 0.5. External validation (100 patients) yielded an AUC of 0.79 (95% CI: 0.71-0.89), with a rate of correct classifications of 73%. Conclusions: The predictive model identifies patients at a higher risk of developing severe COVID-19 at Emergency Department, with a first blood test and common parameters used in a clinical laboratory. This model may be a valuable tool for clinical planning and decision-making.
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Alanine aminotransferase (Alt) provides a molecular link between carbohydrate and amino acid metabolism. In the cell context, the predominant Alt isozyme is located in the cytosol. To gain insight into the transcriptional regulation of the cytosolic alt gene (calt), we cloned and characterized the calt promoter from gilthead sea bream (Sparus aurata). Transient transfection of sea bass larvae cells with deleted calt promoter constructs and electrophoretic mobility shift assays allowed us to identify p300 and c-Myb as new factors in the transcriptional regulation of calt expression. Transfection studies carried out with an acetylase-deficient mutant p300 (p300DY) revealed that the acetyltransferase activity of p300 is essential for the p300-mediated transcriptional activation of S. aurata calt. We had previously found up-regulation of liver cAlt2, an alternatively spliced isoform of calt, under gluconeogenic conditions and in streptozotocin (STZ)-treated S. aurata. Quantitative RT-PCR assays showed that increased p300 and c-Myb mRNA levels in the liver of starved S. aurata contribute to enhancing the transcription of cAlt2. Consistently, the administration of insulin decreased both p300 and c-Myb expression. The mRNA levels of p300 and c-Myb were also analyzed in the liver of STZ-induced diabetic S. aurata. Treatment with STZ increased the expression of p300, whereas it decreased c-Myb. Our findings suggest an involvement of p300 and c-Myb in up-regulation of cAlt2 in the liver of S. aurata under starvation. In addition, these results provide evidence for a role of p300 in diabetes.