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1.
Endocrine ; 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-38507182

RESUMEN

Primary aldosteronism (PA) is the most frequent cause of secondary hypertension and is associated with a higher cardiometabolic risk than essential hypertension. The aim of this consensus is to provide practical clinical recommendations for its surgical and medical treatment, pathology study and biochemical and clinical follow-up, as well as for the approach in special situations like advanced age, pregnancy and chronic kidney disease, from a multidisciplinary perspective, in a nominal group consensus approach of experts from the Spanish Society of Endocrinology and Nutrition (SEEN), Spanish Society of Cardiology (SEC), Spanish Society of Nephrology (SEN), Spanish Society of Internal Medicine (SEMI), Spanish Radiology Society (SERAM), Spanish Society of Vascular and Interventional Radiology (SERVEI), Spanish Society of Laboratory Medicine (SEQC(ML)), Spanish Society of Anatomic-Pathology and Spanish Association of Surgeons (AEC).

2.
Endocrine ; 2024 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-38448679

RESUMEN

Primary aldosteronism (PA) is the most frequent cause of secondary hypertension (HT), and is associated with a higher cardiometabolic risk than essential HT. However, PA remains underdiagnosed, probably due to several difficulties clinicians usually find in performing its diagnosis and subtype classification. The aim of this consensus is to provide practical recommendations focused on the prevalence and the diagnosis of PA and the clinical implications of aldosterone excess, from a multidisciplinary perspective, in a nominal group consensus approach by experts from the Spanish Society of Endocrinology and Nutrition (SEEN), Spanish Society of Cardiology (SEC), Spanish Society of Nephrology (SEN), Spanish Society of Internal Medicine (SEMI), Spanish Radiology Society (SERAM), Spanish Society of Vascular and Interventional Radiology (SERVEI), Spanish Society of Laboratory Medicine (SEQC(ML)), Spanish Society of Anatomic-Pathology, Spanish Association of Surgeons (AEC).

3.
JCEM Case Rep ; 2(1): luad153, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38170043

RESUMEN

Glucocorticoid resistance syndrome is a rare genetic condition characterized by generalized or partial target-tissue insensitivity to glucocorticoids and a consequent hyperactivation of the hypothalamic-pituitary-adrenal axis. Clinical manifestations may include mineralocorticoid and/or androgen excess without manifestations of Cushing syndrome. At a cellular level, glucocorticoid actions are mediated by the nuclear glucocorticoid receptor encoded by the NR3C1 gene. To date, only 33 glucocorticoid receptor loss-of-function pathogenic variants have been associated with glucocorticoid resistance syndrome. The NR3C1 gene has 2 known disease-causing mechanisms: haploinsufficiency and negative dominance. We describe a mother and her son with a mild hyperandrogenic phenotype and a novel genetic variant of the NR3C1 gene predicting a truncated protein and causing glucocorticoid resistance syndrome. To date, no accurate genotype-phenotype correlation has been found.

4.
Endocrine ; 83(3): 747-756, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38214877

RESUMEN

OBJECTIVE: Biochemical suspicion of familial hypocalciuric hypercalcemia (FHH) might provide with a negative (FHH-negative) or positive (FHH-positive) genetic result. Understanding the differences between both groups may refine the identification of those with a positive genetic evaluation, aid management decisions and prospective surveillance. We aimed to compare FHH-positive and FHH-negative patients, and to identify predictive variables for FHH-positive cases. DESIGN: Retrospective, national multi-centre study of patients with suspected FHH and genetic testing of the CASR, AP2S1 and GNA11 genes. METHODS: Clinical, biochemical, radiological and treatment data were collected. We established a prediction model for the identification of FHH-positive cases by logistic regression analysis and area under the ROC curve (AUROC) was estimated. RESULTS: We included 66 index cases, of which 30 (45.5%) had a pathogenic variant. FHH-positive cases were younger (p = 0.029), reported more frequently a positive family history (p < 0.001), presented higher magnesium (p < 0.001) and lower parathormone levels (p < 0.001) and were less often treated for hypercalcemia (p = 0.017) in comparison to FHH-negative cases. Magnesium levels showed the highest AUROC (0.825, 95%CI: 0.709-0.941). The multivariate analysis revealed that family history and magnesium levels were independent predictors of a positive genetic result. The predictive model showed an AUROC of 0.909 (95%CI: 0.826-0.991). CONCLUSIONS: The combination of magnesium and a positive family history offered a good diagnostic accuracy to predict a positive genetic result. Therefore, the inclusion of magnesium measurement in the routine evaluation of patients with suspected FHH might provide insight into the identification of a positive genetic result of any of the CaSR-related genes.


Asunto(s)
Hipercalcemia , Hipercalcemia/congénito , Hiperparatiroidismo Primario , Humanos , Hipercalcemia/diagnóstico , Hipercalcemia/genética , Estudios Retrospectivos , Magnesio , Estudios Prospectivos , Hiperparatiroidismo Primario/diagnóstico
5.
Front Oncol ; 13: 1270962, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38098507

RESUMEN

Background and aims: The spatial and temporal genetic heterogeneity of bladder cancer (BC) makes challenging to find specific drivers of metastatic disease, thus preventing to determine those BC patients at high risk of tumor progression. Our aim was to identify DNA mutations providing aggressive behavior to bladder tumors and analyze them in patients' cell-free DNA (cfDNA) during their follow-up after radical cystectomy (RC) in order to monitor tumor evolution. Methods: Six BC patients who underwent RC and presented disease progression during their follow-up were included. Next-generation sequencing was used to determine somatic mutations in several primary tumor and metastatic specimens from each patient. Shared DNA mutations between primary bladder tumor and metastatic sites were identified in cfDNA samples through droplet digital PCR. Results: Besides BC genetic heterogeneity, specific mutations in at least one of these genes -TERT, ATM, RB1, and FGFR3- were found in primary tumors and their metastases in all patients. These mutations were also identified in the patients' cfDNA at different follow-up time points. Additionally, the dynamic changes of these mutations in cfDNA allowed us to determine tumor evolution in response to treatment. Conclusion: The analysis of BC mutations associated with poor prognosis in plasma cfDNA could be a valuable tool to monitor tumor evolution, thus improving the clinical management of BC patients.

6.
Genes (Basel) ; 14(4)2023 03 28.
Artículo en Inglés | MEDLINE | ID: mdl-37107571

RESUMEN

Neurological disorders (ND) are diseases that affect the brain and the central and autonomic nervous systems, such as neurodevelopmental disorders, cerebellar ataxias, Parkinson's disease, or epilepsies. Nowadays, recommendations of the American College of Medical Genetics and Genomics strongly recommend applying next generation sequencing (NGS) as a first-line test in patients with these disorders. Whole exome sequencing (WES) is widely regarded as the current technology of choice for diagnosing monogenic ND. The introduction of NGS allows for rapid and inexpensive large-scale genomic analysis and has led to enormous progress in deciphering monogenic forms of various genetic diseases. The simultaneous analysis of several potentially mutated genes improves the diagnostic process, making it faster and more efficient. The main aim of this report is to discuss the impact and advantages of the implementation of WES into the clinical diagnosis and management of ND. Therefore, we have performed a retrospective evaluation of WES application in 209 cases referred to the Department of Biochemistry and Molecular Genetics of the Hospital Clinic of Barcelona for WES sequencing derived from neurologists or clinical geneticists. In addition, we have further discussed some important facts regarding classification criteria for pathogenicity of rare variants, variants of unknown significance, deleterious variants, different clinical phenotypes, or frequency of actionable secondary findings. Different studies have shown that WES implementation establish diagnostic rate around 32% in ND and the continuous molecular diagnosis is essential to solve the remaining cases.


Asunto(s)
Epilepsia , Exoma , Humanos , Secuenciación del Exoma , Estudios Retrospectivos , Exoma/genética , Fenotipo , Epilepsia/diagnóstico , Epilepsia/genética
7.
Endocrinol Diabetes Nutr (Engl Ed) ; 69(1): 63-69, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-35232561

RESUMEN

Prolactin measurement is very common in standard clinical practice. It is indicated not only in the study of pituitary adenomas, but also when there are problems with fertility, decreased libido, or menstrual disorders, among other problems. Inadequate interpretation of prolactin levels without contextualizing the laboratory results with the clinical, pharmacological, and gynecological/urological history of patients leads to erroneous diagnoses and, thus, to poorly based studies and treatments. Macroprolactinemia, defined as hyperprolactinemia due to excess macroprolactin (an isoform of a greater molecular weight than prolactin but with less biological activity), is one of the main causes of such erroneous diagnoses, resulting in poor patient management when not recognized. There is no unanimous agreement as to when macroprolactin screening is required in patients with hyperprolactinemia. At some institutions, macroprolactin testing by polyethylene glycol (PEG) precipitation is routinely performed in all patients with hyperprolactinemia, while others use a clinically based approach. There is also no consensus on how to express the results of prolactin/macroprolactin levels after PEG, which in some cases may lead to an erroneous interpretation of the results. The objectives of this study were: 1. To establish the strategy for macroprolactin screening by serum precipitation with PEG in patients with hyperprolactinemia: universal screening versus a strategy guided by the alert generated by the clinician based on the absence or presence of clinical symptoms or by the laboratory when hyperprolactinemia is detected. 2. To create a consensus document that standardizes the reporting of prolactin results after precipitation with PEG to minimize errors in the interpretation of the results, in line with international standards.


Asunto(s)
Hiperprolactinemia , Neoplasias Hipofisarias , Humanos , Hiperprolactinemia/diagnóstico , Hiperprolactinemia/etiología , Laboratorios , Neoplasias Hipofisarias/complicaciones , Neoplasias Hipofisarias/diagnóstico , Prolactina
9.
Endocrinol Diabetes Nutr (Engl Ed) ; 68(4): 260-269, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34266638

RESUMEN

Familial non-medullary thyroid cancer is defined as the presence of non-medullary thyroid cancer in two or more first-degree relatives, in the absence of other predisposing factors. It represents up to 9% of differentiated thyroid cancers, and only a minority appears in well-known hereditary syndromes that associate thyroid cancer among many other clinical manifestations. However, in more than 95% of cases, thyroid cancer appears isolated, and its genetic causes have yet to be elucidated. We review here the current knowledge of the genetic basis of this pathology, as well as its clinical characteristics. Understanding the genetic mechanisms implied would help to comprehend the metabolic pathways involved, with the consequent potential therapeutic application. In addition, it would allow genetic counseling and to focus our efforts on patients at risk of developing this disorder.


Asunto(s)
Síndromes Neoplásicos Hereditarios , Cáncer Papilar Tiroideo , Neoplasias de la Tiroides , Humanos , Síndromes Neoplásicos Hereditarios/genética , Cáncer Papilar Tiroideo/genética , Neoplasias de la Tiroides/genética
10.
Am J Med Genet A ; 185(12): 3872-3876, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34313384

RESUMEN

Pheochromocytoma/paraganglioma (Pheo/PGL) associated with pituitary adenoma (PA) is rare in clinical practice, and a common pathogenic mechanism has been suggested owing to the germline pathogenic variants found in some cases. Our aim is to propose a reassignment for a recurrent MEN1 genetic variant found in a 54-year-old male patient with bilateral pheochromocytoma and GH-secreting PA. Pheo/PGL genes study was carried out in DNA samples from Pheo as well as PA and no pathological variants or large deletions were detected. Additionally, a MEN1 gene analysis was performed, and a heterozygous germline variant in exon 10: c.1618C>T; p.(Pro540Ser) was found. No MEN1 gene deletions/duplications were detected. In evaluating a causal relationship between the c.1618C>T MEN1 variant and both tumors, we took into account that missense variants are common pathogenic variants in MEN1, and the population frequency of this variant is too high to be considered pathogenic. His son (aged 38 and carrier) is asymptomatic, and computational analysis showed discrepancies. We propose that this recurrent variant, previously considered as likely pathogenic, subsequently as variant of uncertain significance, and likely benign should now be reclassified as benign.


Asunto(s)
Paraganglioma/genética , Feocromocitoma/genética , Neoplasias Hipofisarias/genética , Proteínas Proto-Oncogénicas/genética , Adulto , Mutación de Línea Germinal , Heterocigoto , Humanos , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/genética , Recurrencia Local de Neoplasia/patología , Paraganglioma/complicaciones , Paraganglioma/patología , Feocromocitoma/complicaciones , Feocromocitoma/patología , Neoplasias Hipofisarias/complicaciones , Neoplasias Hipofisarias/patología
11.
Artículo en Inglés, Español | MEDLINE | ID: mdl-33903089

RESUMEN

Prolactin measurement is very common in standard clinical practice. It is indicated not only in the study of pituitary adenomas, but also when there are problems with fertility, decreased libido, or menstrual disorders, among other problems. Inadequate interpretation of prolactin levels without contextualizing the laboratory results with the clinical, pharmacological, and gynecological/urological history of patients leads to erroneous diagnoses and, thus, to poorly based studies and treatments. Macroprolactinemia, defined as hyperprolactinemia due to excess macroprolactin (an isoform of a greater molecular weight than prolactin but with less biological activity), is one of the main causes of such erroneous diagnoses, resulting in poor patient management when not recognized. There is no unanimous agreement as to when macroprolactin screening is required in patients with hyperprolactinemia. At some institutions, macroprolactin testing by polyethylene glycol (PEG) precipitation is routinely performed in all patients with hyperprolactinemia, while others use a clinically based approach. There is also no consensus on how to express the results of prolactin/macroprolactin levels after PEG, which in some cases may lead to an erroneous interpretation of the results. The objectives of this study were: 1. To establish the strategy for macroprolactin screening by serum precipitation with PEG in patients with hyperprolactinemia: universal screening versus a strategy guided by the alert generated by the clinician based on the absence or presence of clinical symptoms or by the laboratory when hyperprolactinemia is detected. 2. To create a consensus document that standardizes the reporting of prolactin results after precipitation with PEG to minimize errors in the interpretation of the results, in line with international standards.

12.
Fam Cancer ; 20(3): 253-256, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33084974

RESUMEN

Multiple endocrine neoplasia type 2 (MEN 2) is an autosomal dominant inherited disease, characterized by germ-line variants in RET proto-oncogene. Variants are frequently located in the RET extracellular cysteine-rich region domain, mainly affecting cysteines which are replaced by an alternative amino acid, resulting in a mispaired cysteine and the generation of RET dimers. We describe a novel c.1765A > T variant of RET proto-oncogene in a family with medullary thyroid carcinoma (MTC) that predicts the creation of an additional cysteine p.(Ser589Cys) in the cysteine-rich domain. In this site only three other punctual variants have been described, giving rise to extra cysteines. We have characterized the clinical phenotype of this family. The index case was a 79-year-old woman with MTC in both thyroid lobes. This variant co-segregates in this family in four affected members. One member was operated on at 31 years of age and already presented MTC, indicating that prophylactic thyroidectomy was appropriated. Variants predicting additional cysteines are not frequent in RET, and when present, they allow us to understand their implication in the disease. According to clinical data obtained in this family, this variant could be categorized as a moderate-risk of the disease.


Asunto(s)
Carcinoma Medular/congénito , Cisteína , Mutación de Línea Germinal , Neoplasia Endocrina Múltiple Tipo 2a/genética , Proteínas Proto-Oncogénicas c-ret/genética , Neoplasias de la Tiroides/genética , Adulto , Anciano , Carcinoma Medular/genética , Femenino , Heterocigoto , Humanos , Masculino , Persona de Mediana Edad , Linaje , Fenotipo , Procedimientos Quirúrgicos Profilácticos , Tiroidectomía
13.
Endocrinol Diabetes Nutr (Engl Ed) ; 68(4): 260-269, 2021 Apr.
Artículo en Inglés, Español | MEDLINE | ID: mdl-33191196

RESUMEN

Familial non-medullary thyroid cancer is defined as the presence of non-medullary thyroid cancer in two or more first-degree relatives, in the absence of other predisposing factors. It represents up to 9% of differentiated thyroid cancers, and only a minority appears in well-known hereditary syndromes that associate thyroid cancer among many other clinical manifestations. However, in more than 95% of cases, thyroid cancer appears isolated, and its genetic causes have yet to be elucidated. We review here the current knowledge of the genetic basis of this pathology, as well as its clinical characteristics. Understanding the genetic mechanisms implied would help to comprehend the metabolic pathways involved, with the consequent potential therapeutic application. In addition, it would allow genetic counseling and to focus our efforts on patients at risk of developing this disorder.

14.
Horm Cancer ; 11(2): 111-116, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32172474

RESUMEN

To date, the genes involved in familial non-medullary thyroid cancer (FNMTC) remain poorly understood, with the exception of syndromic cases of FNMTC. It has been proposed that germline mutations in telomere-related genes, such as POT1, described in familial melanoma might also predispose individuals to thyroid cancer, requiring further research. We aimed to identify germline mutations in POT1 in selected FNMTC families (with at least three affected members) without a history of other cancers or other features, and to describe the clinical characteristics of these families. Sequencing of the 5'UTR and coding regions of POT1 was performed in seven affected people (index cases) from seven families with FNMTC. In addition, we performed whole-exome sequencing (WES) of DNA from 10 affected individuals belonging to four of these families. We did not find germline variants of interest in POT1 by Sanger sequencing or WES. We neither found putative causative mutations in genes previously described as candidate genes for FNMTC in the 4 families studied by WES. In our study, no germline potentially pathogenic mutations were detected in POT1, minimizing the possibilities that this gene could be substantially involved in non-syndromic FNMTC.


Asunto(s)
Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Proteínas de Unión a Telómeros/genética , Cáncer Papilar Tiroideo/genética , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mutación , Complejo Shelterina , Adulto Joven
15.
Genes (Basel) ; 10(11)2019 11 07.
Artículo en Inglés | MEDLINE | ID: mdl-31703244

RESUMEN

Nonsyndromic familial non-medullary thyroid cancer (FNMTC) represents 3-9% of thyroid cancers, but the susceptibility gene(s) remain unknown. We designed this multicenter study to analyze families with nonsyndromic FNMTC and identify candidate susceptibility genes. We performed exome sequencing of DNA from four affected individuals from one kindred, with five cases of nonsyndromic FNMTC. Single Nucleotide Variants, and insertions and deletions that segregated with all the affected members, were analyzed by Sanger sequencing in 44 additional families with FNMTC (37 with two affected members, and seven with three or more affected members), as well as in an independent control group of 100 subjects. We identified the germline variant p. Asp31His in NOP53 gene (rs78530808, MAF 1.8%) present in all affected members in three families with nonsyndromic FNMTC, and not present in unaffected spouses. Our functional studies of NOP53 in thyroid cancer cell lines showed an oncogenic function. Immunohistochemistry exhibited increased NOP53 protein expression in tumor samples from affected family members, compared with normal adjacent thyroid tissue. Given the relatively high frequency of the variant in the general population, these findings suggest that instead of a causative gene, NOP53 is likely a low-penetrant gene implicated in FNMTC, possibly a modifier.


Asunto(s)
Genes Modificadores , Polimorfismo de Nucleótido Simple , Neoplasias de la Tiroides/genética , Proteínas Supresoras de Tumor/genética , Línea Celular Tumoral , Femenino , Mutación de Línea Germinal , Humanos , Masculino , Mutación Missense , Linaje , Penetrancia , Glándula Tiroides/metabolismo , Neoplasias de la Tiroides/patología
17.
Endocr Connect ; 8(10): 1416-1424, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31557724

RESUMEN

Primary hyperparathyroidism is the most frequent manifestation of multiple endocrine neoplasia type 1 (MEN1) syndrome. Bone and renal complications are common. Surgery is the treatment of choice, but the best timing for surgery is controversial and predictors of persistence and recurrence are not well known. Our study describes the clinical characteristics and the surgical outcomes, after surgery and in the long term, of the patients with MEN1 and primary hyperparathyroidism included in the Spanish Registry of Multiple Endocrine Neoplasia, Pheochromocytomas and Paragangliomas (REGMEN). Eighty-nine patients (49 men and 40 women, 34.2 ± 13 years old) were included. Sixty-four out of the 89 underwent surgery: a total parathyroidectomy was done in 13 patients, a subtotal parathyroidectomy in 34 and a less than subtotal parathyroidectomy in 15. Remission rates were higher after a total or a subtotal parathyroidectomy than after a less than subtotal (3/4 and 20/22 vs 7/12, P < 0.05), without significant differences in permanent hypoparathyroidism (1/5, 9/23 and 0/11, N.S.). After a median follow-up of 111 months, 20 of the 41 operated patients with long-term follow-up had persistent or recurrent hyperparathyroidism. We did not find differences in disease-free survival rates between different techniques, patients with or without permanent hypoparathyroidism and patients with different mutated exons, but a second surgery was more frequent after a less than subtotal parathyroidectomy.

19.
Head Neck ; 41(1): 79-91, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30549360

RESUMEN

BACKGROUND: Succinate dehydrogenase subunit B (SDHB) immunohistochemistry was considered a valuable tool to identify patients with inherited paraganglioma/pheochromocytoma (PGL/PCC). However, previous studies jointly analyzed 2 related but clinically distinct entities, parasympathetic head and neck paragangliomas (HNPGLs) and sympathetic PCCs/PGLs. Additionally, a role for hypoxia inducible factor-1α (HIF-1α) as a biomarker for succinate dehydrogenase (SDHx)-mutated tumors has not been studied. Here, we evaluated the utility of SDHB/HIF-1α proteins in HNPGLs and PCCs/PGLs as clinically useful biomarkers. METHODS: The SDHB/succinate dehydrogenase subunit A (SDHA)/HIF-1α immunohistochemistry analysis was performed in 158 genetically defined patients. RESULTS: Similarly to PCCs/PGLs, SDHB immune-negativity correlated with SDHx-mutations in HNPGLs (P < .0001). The HIF-1α stabilization was associated with SDHx-mutations in HNPGLs (P = .020), not in PCCs/PGLs (P = .319). However, 25% of SDHx-HNPGLs lacked HIF-1α positive cells. CONCLUSION: As in PCCs/PGLs, SDHB immunohistochemistry in HNPGLs is a valuable method for identification of candidates for SDHx-genetic testing. On the contrary, although SDHx mutations may favor HIF-1α stabilization in HNPGLs, this is not a clinically useful biomarker.


Asunto(s)
Neoplasias de las Glándulas Suprarrenales/metabolismo , Neoplasias de Cabeza y Cuello/metabolismo , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Paraganglioma Extraadrenal/metabolismo , Feocromocitoma/metabolismo , Succinato Deshidrogenasa/genética , Neoplasias de las Glándulas Suprarrenales/genética , Adulto , Biomarcadores de Tumor/metabolismo , Femenino , Mutación de Línea Germinal , Neoplasias de Cabeza y Cuello/genética , Humanos , Inmunohistoquímica , Masculino , Paraganglioma Extraadrenal/genética , Feocromocitoma/genética , Valor Predictivo de las Pruebas , Sensibilidad y Especificidad , Succinato Deshidrogenasa/metabolismo
20.
Biochim Biophys Acta Mol Basis Dis ; 1864(7): 2385-2394, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29704611

RESUMEN

Glucokinase (GCK) plays a key role in glucose homeostasis. Heterozygous inactivating mutations in the GCK gene cause the familial, mild fasting hyperglycaemia named MODY2. Besides its particular kinetic characteristics, glucokinase is regulated by subcellular compartmentation in hepatocytes. Glucokinase regulatory protein (GKRP) binds to GCK, leading to enzyme inhibition and import into the nucleus at fasting. When glucose concentration increases, GCK-GKRP dissociates and GCK is exported to the cytosol due to a nuclear export signal (NES). With the aim to characterize the GCK-NES, we have functionally analysed nine MODY2 mutations located within the NES sequence. Recombinant GCK mutants showed reduced catalytic activity and, in most cases, protein instability. Most of the mutants interact normally with GKRP, although mutations L306R and L309P impair GCK nuclear import in cotransfected cells. We demonstrated that GCK-NES function depends on exportin 1. We further showed that none of the mutations fully inactivate the NES, with the exception of mutation L304P, which likely destabilizes its α-helicoidal structure. Finally, we found that residue Glu300 negatively modulates the NES activity, whereas other residues have the opposite effect, thus suggesting that some of the NES spacer residues contribute to the low affinity of the NES for exportin 1, which is required for its proper functioning. In conclusion, our results have provided functional and structural insights regarding the GCK-NES and contributed to a better knowledge of the molecular mechanisms involved in the nucleo-cytoplasmic shuttling of glucokinase. Impairment of this regulatory mechanism by some MODY2 mutations might contribute to the hyperglycaemia in the patients.


Asunto(s)
Núcleo Celular/enzimología , Citoplasma/enzimología , Diabetes Mellitus Tipo 2 , Glucoquinasa , Hepatocitos/enzimología , Mutación Missense , Señales de Exportación Nuclear/genética , Adulto , Sustitución de Aminoácidos , Núcleo Celular/patología , Citoplasma/patología , Diabetes Mellitus Tipo 2/enzimología , Diabetes Mellitus Tipo 2/genética , Femenino , Glucoquinasa/genética , Glucoquinasa/metabolismo , Células HEK293 , Humanos , Carioferinas/genética , Carioferinas/metabolismo , Receptores Citoplasmáticos y Nucleares/genética , Receptores Citoplasmáticos y Nucleares/metabolismo
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