RESUMO
Vitamin D hydroxylation-deficient rickets type 1A is an autosomal recessive disorder caused by pathogenic variants in CYP27B1 gene, which encodes for 1α-hydroxylase, the enzyme responsible for the conversion of 25-OH vitamin D into its active form 1,25(OH)2 vitamin D. We report the case of a 3-year-old female Mexican patient with growth retardation and progressive bone deformity, whose laboratory studies showed 25-OH vitamin D deficiency, a normal serum calcium and an elevated intact parathyroid hormone level that remained high despite calcitriol, cholecalciferol, and calcium supplementation. 99mTc sestamibi gammagram showed findings suggestive of parathyroid hyperplasia. Bone histomorphometry showed an image consistent with hyperparathyroidism without findings of osteomalacia, so normocalcemic primary hyperparathyroidism was suspected and a subtotal parathyroidectomy was performed, with the patient developing postoperative hypoparathyroidism. When she arrived at our clinic at age 18 years, she showed calcium- and calcitriol-dependent hypocalcemia, with secondary hyperparathyroidism and low levels of 1,25(OH)2 vitamin D in the absence of a 25-OH vitamin D deficiency, reflecting a defect in 1α-hydroxylation. Molecular testing revealed compound heterozygous variants in CYP27B1 gene. This is the first reported case of an inherited disorder of vitamin D metabolism that was diagnosed and surgically treated as primary hyperparathyroidism.
RESUMO
BACKGROUND: Nonspecific chronic neck pain is a fairly common disorder that causes a great impact, and it is greatly influenced by psychosocial factors. Among a number of treatment modalities described for its management, the most common approach is based on manual therapy and specific therapeutic exercise, which have shown a moderate effect on subjects with chronic non-specific neck pain. However, the effect times of these treatments have not been accurately detailed. Our study aims to break down and compare the effects of two experimental treatments based on manual therapy and therapeutic exercise. METHODS: The short-term and mid-term changes produced by different therapies on subjects with non-specific chronic neck pain were studied. The sample was randomized divided into three groups: manual therapy, therapeutic exercise, and placebo. As dependent variables of our research, we studied (a) pain, based on the visual analog scale and the pressure pain threshold, and (b) cervical disability, through the Neck Disability Index (NDI). Outcomes were registered on week 1, week 4, and week 12. The findings were analyzed statistically considering a 5% significance level (P ≤ 0.05). RESULTS: No statistically significant differences (P 0.05) were obtained between the experimental groups, if they exist against the control group. Nonetheless, we found that manual therapy improved perceived pain before than therapeutic exercise, while therapeutic exercise reduced cervical disability before than manual therapy. Effect size (R2) shows medium and large effects for both experimental treatments. CONCLUSION: There are no differences between groups in short and medium terms. Manual therapy achieves a faster reduction in pain perception than therapeutic exercise. Therapeutic exercise reduces disability faster than manual therapy. Clinical improvement could potentially be influenced by central processes. TRIAL REGISTRATION: Brazilian Clinical Trial Registry, RBR-2vj7sw. Registered on 28 November 2018.
Assuntos
Dor Crônica/terapia , Terapia por Exercício , Manipulações Musculoesqueléticas , Cervicalgia/terapia , Brasil , Dor Crônica/diagnóstico , Humanos , Cervicalgia/diagnóstico , Resultado do TratamentoRESUMO
As Parkinson's disease progresses, a massive loss of dopaminergic neurons is accompanied by accumulation of alpha-Synuclein (αSyn) neuronal inclusions called Lewy bodies and Lewy neurites. Inclusions first appear in olfactory bulb and enteric neurons then in ascendant neuroanatomical interconnected areas, and finally, in late stages of the disease, Lewy bodies are observed in a substantia nigra pars compacta with clear signs of neuronal loss. It is believed that the spreading of Lewy bodies through the nervous system is a consequence of the cell-to-cell propagation of αSyn, that can occur via sequential steps of secretion and uptake. Certain pathological forms of transmitted αSyn are able to seed endogenous counterparts in healthy recipient cells, thus promoting the self-sustained cycle of inclusion formation, amplification and spreading, that ultimately underlies disease progression. Here we review the cell-to-cell propagation of αSyn focusing on its role in the progression of Parkinson's disease.
RESUMO
The P2X7 receptor is a member of the P2X family of ligand-gated ion channels. A single-nucleotide polymorphism leading to a glutamine (Gln) by arginine (Arg) substitution at codon 460 of the purinergic P2X7 receptor (P2X7R) has been associated with mood disorders. No change in function (loss or gain) has been described for this SNP so far. Here we show that although the P2X7R-Gln460Arg variant per se is not compromised in its function, co-expression of wild-type P2X7R with P2X7R-Gln460Arg impairs receptor function with respect to calcium influx, channel currents and intracellular signaling in vitro. Moreover, co-immunoprecipitation and FRET studies show that the P2X7R-Gln460Arg variant physically interacts with P2X7R-WT. Specific silencing of either the normal or polymorphic variant rescues the heterozygous loss of function phenotype and restores normal function. The described loss of function due to co-expression, unique for mutations in the P2RX7 gene so far, explains the mechanism by which the P2X7R-Gln460Arg variant affects the normal function of the channel and may represent a mechanism of action for other mutations.
Assuntos
Polimorfismo de Nucleotídeo Único/genética , Receptores Purinérgicos P2X7/fisiologia , Western Blotting , Cálcio/metabolismo , Cálcio/fisiologia , Transferência Ressonante de Energia de Fluorescência , Células HEK293 , Humanos , Imunoprecipitação , Técnicas de Patch-Clamp , Polimorfismo de Nucleotídeo Único/fisiologia , RNA Interferente Pequeno/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Receptores Purinérgicos P2X7/genética , Receptores Purinérgicos P2X7/metabolismo , Transdução de Sinais/fisiologiaRESUMO
Glucocorticoid receptor (GR) activity is modulated by posttranslational modifications, including phosphorylation, ubiquitination, and SUMOylation. The GR has three SUMOylation sites: lysine 297 (K297) and K313 in the N-terminal domain (NTD) and K721 within the ligand-binding domain. SUMOylation of the NTD sites mediates the negative effect of the synergy control motifs of GR on promoters with closely spaced GR binding sites. There is scarce evidence on the role of SUMO conjugation to K721 and its impact on GR transcriptional activity. We have previously shown that RSUME (RWD-containing SUMOylation enhancer) increases protein SUMOylation. We now demonstrate that RSUME interacts with the GR and increases its SUMOylation. RSUME regulates GR transcriptional activity and the expression of its endogenous target genes, FKBP51 and S100P. RSUME uncovers a positive role for the third SUMOylation site, K721, on GR-mediated transcription, demonstrating that GR SUMOylation acts positively in the presence of a SUMOylation enhancer. Both mutation of K721 and small interfering RNA-mediated RSUME knockdown diminish GRIP1 coactivator activity. RSUME, whose expression is induced under stress conditions, is a key factor in heat shock-induced GR SUMOylation. These results show that inhibitory and stimulatory SUMO sites are present in the GR and at higher SUMOylation levels the stimulatory one becomes dominant.
Assuntos
Receptores de Glucocorticoides/genética , Receptores de Glucocorticoides/metabolismo , Fatores de Transcrição/metabolismo , Animais , Arginina/genética , Células COS , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Linhagem Celular , Chlorocebus aethiops , Resposta ao Choque Térmico/fisiologia , Mutação , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Estrutura Terciária de Proteína , Ratos , Sumoilação , Fatores de Transcrição/genética , Ativação TranscricionalRESUMO
RSUME (RWD-containing SUMO Enhancer) is a small protein that increases SUMO conjugation to proteins. To date, four splice variants that codify three RSUME isoforms have been described, which differ in their C-terminal end. Comparing the structure of the RSUME isoforms we found that, in addition to the previously described RWD domain in the N-terminal, all these RSUME variants also contain an intermediate domain. Only the longest RSUME isoform presents a C-terminal domain that is absent in the others. Given these differences, we used the shortest and longest RSUME variants for comparative studies. We found that the C-terminal domain is dispensable for the SUMO-conjugation enhancer properties of RSUME. We also demonstrate that these two RSUME variants are equally induced by hypoxia. The NF-κB signaling pathway is inhibited and the HIF-1 pathway is increased more efficiently by the longest RSUME, by means of a greater physical interaction of RSUME267 with the target proteins. In addition, the mRNA and protein levels of these isoforms differ in human glioma samples; while the shortest RSUME isoform is expressed in all the tumors analyzed, the longest variant is expressed in most but not all of them. The results presented here show a degree of redundancy of the RSUME variants on the SUMO pathway. However, the increased inhibition conferred by RSUME267 over the NF-κB signaling pathway, the increased activation over the HIF-1 pathway and the different expression of the RSUME isoforms suggest specific roles for each RSUME isoform which may be relevant in certain types of brain tumors that express RSUME, like human pituitary adenomas and gliomas.
Assuntos
Biologia Computacional , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo , Sequência de Aminoácidos , Animais , Linhagem Celular , Regulação da Expressão Gênica , Humanos , Fator 1 Induzível por Hipóxia/metabolismo , Modelos Moleculares , Dados de Sequência Molecular , NF-kappa B/metabolismo , Isoformas de Proteínas/química , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Estrutura Secundária de Proteína , Proteína SUMO-1/metabolismo , Transdução de Sinais , Fatores de Transcrição/genéticaRESUMO
Protein modification by conjugation of small ubiquitin-related modifier (SUMO) is involved in diverse biological functions, such as transcription regulation, subcellular partitioning, stress response, DNA damage repair, and chromatin remodeling. Here, we show that the serine/arginine-rich protein SF2/ASF, a factor involved in splicing regulation and other RNA metabolism-related processes, is a regulator of the sumoylation pathway. The overexpression of this protein stimulates, but its knockdown inhibits SUMO conjugation. SF2/ASF interacts with Ubc9 and enhances sumoylation of specific substrates, sharing characteristics with already described SUMO E3 ligases. In addition, SF2/ASF interacts with the SUMO E3 ligase PIAS1 (protein inhibitor of activated STAT-1), regulating PIAS1-induced overall protein sumoylation. The RNA recognition motif 2 of SF2/ASF is necessary and sufficient for sumoylation enhancement. Moreover, SF2/ASF has a role in heat shock-induced sumoylation and promotes SUMO conjugation to RNA processing factors. These results add a component to the sumoylation pathway and a previously unexplored role for the multifunctional SR protein SF2/ASF.
Assuntos
Proteínas Nucleares/metabolismo , Proteínas de Ligação a RNA/metabolismo , Proteína SUMO-1/metabolismo , Linhagem Celular , Resposta ao Choque Térmico , Humanos , Proteínas Nucleares/genética , Ligação Proteica , RNA Interferente Pequeno/genética , Proteínas de Ligação a RNA/genética , Fatores de Processamento de Serina-Arginina , Especificidade por Substrato , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Enzimas de Conjugação de Ubiquitina/genética , Enzimas de Conjugação de Ubiquitina/metabolismoRESUMO
Research performed on the pituitary has proven that cytokines play an important role in maintaining pituitary physiology, affecting not only cell proliferation but also hormone secretion. The effects of cytokines can be autocrine or paracrine. This review gives an overview on the effects of the most studied cytokines in the pituitary. Special interest is focused on interleukin-6 (IL-6) because it has the distinctive characteristic of stimulating pituitary tumor cell growth, but has the opposite effect on normal pituitary cells. On the other hand, IL-6 is a cytokine of interest in the pituitary because recent work has shown that it promotes and maintains senescence in certain types of tumors. Given that the majority of pituitary adenomas are microadenomas and the fact that clinically inapparent pituitary tumors are quite common, senescence, perhaps mediated by IL-6, is an attractive mechanism for explaining the benign nature of pituitary tumors.
Assuntos
Citocinas/fisiologia , Hipófise/fisiologia , Adenoma/etiologia , Animais , Senescência Celular/fisiologia , Citocinas/metabolismo , Humanos , Interleucina-6/fisiologia , Modelos Biológicos , Hipófise/crescimento & desenvolvimento , Hipófise/metabolismo , Hipófise/patologia , Neoplasias Hipofisárias/etiologiaRESUMO
Although several genes and signalling pathways have been identified as important effectors in the development of pituitary tumours, our understanding of pituitary tumorigenesis remains incomplete and is the focus of much current research. Use of the mRNA differential display technique in prolactinomas from D2-receptor knockout mice and in stable GH3 cell line clones with enhanced tumorigenicity in vivo has led to the identification of two genes that are involved in the pathogenic process--BMP-4 and RSUME. Bone morphogenetic protein-4 (BMP-4) has been found to have a crucial role in prolactinoma development and also in signalling crosstalk with oestrogens. In contrast, BMP-4 has an inhibitory role in corticotrophinomas. RSUME (RWD-containing sumoylation enhancer) was identified from a transformed lactosomatotrophic cell line that had increased tumorigenic and angiogenic potential. Expression of RSUME was induced under hypoxic conditions and it has a potential role during vascularization. The differential expression and action of BMP-4 in prolactinomas and corticotrophinomas highlights the importance of studying a gene with contrasting actions in two cell lineages of the same organ in order to understand the pituitary transformation process. Both BMP-4 and RSUME may be interesting targets for inhibiting steps involved in pituitary tumorigenesis.
Assuntos
Proteína Morfogenética Óssea 4/biossíntese , Regulação Neoplásica da Expressão Gênica , Modelos Biológicos , Proteínas de Neoplasias/biossíntese , Prolactinoma/metabolismo , Fatores de Transcrição/biossíntese , Animais , Proteína Morfogenética Óssea 4/genética , Hipóxia Celular/genética , Linhagem Celular Tumoral , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Perfilação da Expressão Gênica , Humanos , Camundongos , Camundongos Knockout , Proteínas de Neoplasias/genética , Prolactinoma/genética , Prolactinoma/terapia , Receptores de Dopamina D2/genética , Receptores de Dopamina D2/metabolismo , Transdução de Sinais/genética , Fatores de Transcrição/genéticaRESUMO
SUMO conjugation to proteins is involved in the regulation of diverse cellular functions. We have identified a protein, RWD-containing sumoylation enhancer (RSUME), that enhances overall SUMO-1, -2, and -3 conjugation by interacting with the SUMO conjugase Ubc9. RSUME increases noncovalent binding of SUMO-1 to Ubc9 and enhances Ubc9 thioester formation and SUMO polymerization. RSUME enhances the sumoylation of IkB in vitro and in cultured cells, leading to an inhibition of NF-kB transcriptional activity. RSUME is induced by hypoxia and enhances the sumoylation of HIF-1alpha, promoting its stabilization and transcriptional activity during hypoxia. Disruption of the RWD domain structure of RSUME demonstrates that this domain is critical for RSUME action. Together, these findings point to a central role of RSUME in the regulation of sumoylation and, hence, several critical regulatory pathways in mammalian cells.