Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 44
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Int J Mol Sci ; 23(4)2022 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-35216216

RESUMO

The discovery that osteocytes secrete phosphaturic fibroblast growth factor 23 (FGF23) has defined bone as an endocrine organ. However, the autocrine and paracrine functions of FGF23 are still unknown. The present study focuses on the cellular and molecular mechanisms involved in the complex control of FGF23 production and local bone remodeling functions. FGF23 was assayed using ELISA kit in the presence or absence of 17ß-estradiol in starved MLO-Y4 osteocytes. In these cells, a relationship between oxidative stress-induced apoptosis and up-regulation of active FGF23 levels due to MAP Kinases activation with involvement of the transcriptional factor (NF-kB) has been demonstrated. The active FGF23 increase can be due to up-regulation of its expression and post-transcriptional modifications. 17ß-estradiol prevents the increase of FGF23 by inhibiting JNK and NF-kB activation, osteocyte apoptosis and by the down-regulation of osteoclastogenic factors, such as sclerostin. No alteration in the levels of dentin matrix protein 1, a FGF23 negative regulator, has been determined. The results of this study identify biological targets on which drugs and estrogen may act to control active FGF23 levels in oxidative stress-related bone and non-bone inflammatory diseases.


Assuntos
Apoptose/efeitos dos fármacos , Estradiol/farmacologia , Fator de Crescimento de Fibroblastos 23/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Remodelação Óssea/efeitos dos fármacos , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/metabolismo , Linhagem Celular , Regulação para Baixo/efeitos dos fármacos , Estrogênios/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Camundongos , Osteócitos/efeitos dos fármacos , Osteócitos/metabolismo , Osteogênese/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos
2.
Calcif Tissue Int ; 108(1): 91-103, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32409880

RESUMO

The main congenital conditions of hypophosphatemia expressed in adulthood include several forms of hereditary hypophosphatemic rickets and a congenital disorder of vitamin D metabolism characterized by osteomalacia and hypophosphatemia in adult patients. Hypophosphatemia in adults is defined as serum phosphate concentration < 0.80 mmol/L. The principal regulators of phosphate homeostasis, as is well known, are parathyroid hormone (PTH), activated vitamin D, and Fibroblast Growth Factor 23 (FGF23). Differential diagnosis of hypophosphatemia is based on the evaluation of mechanisms leading to this alteration, such as high PTH activity, inadequate phosphate absorption from the gut, or renal phosphate wasting, either due to primary tubular defects or high FGF23 levels. The most common inherited form associated to hypophosphatemia is X-linked hypophosphatemic rickets (XLH), caused by PHEX gene mutations with enhanced secretion of the FGF23. Until now, the management of hypophosphatemia in adulthood has been poorly investigated. It is widely debated whether adult patients benefit from the conventional treatments normally used for pediatric patients. The new treatment for XLH with burosumab, a recombinant human IgG1 monoclonal antibody that binds to FGF23, blocking its activity, may change the pharmacological management of adult subjects with hypophosphatemia associated to FGF23-dependent mechanisms.


Assuntos
Raquitismo Hipofosfatêmico Familiar , Hipofosfatemia , Osteomalacia , Adulto , Anticorpos Monoclonais , Anticorpos Monoclonais Humanizados/farmacologia , Fator de Crescimento de Fibroblastos 23 , Fatores de Crescimento de Fibroblastos , Humanos , Osteomalacia/congênito , Endopeptidase Neutra Reguladora de Fosfato PHEX/genética , Fosfatos
3.
Calcif Tissue Int ; 103(2): 144-150, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29516129

RESUMO

Epidemiological data on prevalence and incidence of chronic hypoparathyroidism are still scarce. This study aimed to establish prevalence of chronic hypoparathyroidism and incidence of surgical hypoparathyroidism using the analysis of electronic anonymous public health care database. Data referred to a 5-year period (2009-2013, Region of Tuscany, Italy, as a sample representative of the whole Mediterranean/European population, estimated mean population: 3,750,000 inhabitants) were retrieved by the analysis of pharmaceutical distribution dataset, containing data related to drugs reimbursed by public health system, hospital discharge and procedures codes, and ICD9 exemption codes for chronic diseases. The application of a specific algorithm was applied to indirectly identify people with chronic hypoparathyroidism as assuming chronic therapy with active vitamin D metabolites (AVDM). The number of people taking AVDM for a period equal to or longer than 6 months till the end of the study period, with ICD9 exemption code for hypoparathyroidism, and with a disease-related discharge code were identified. Within this restricted group, patients with chronic kidney disease and osteoporosis were excluded. The indirect estimate of chronic hypoparathyroidism in a European Mediterranean subpopulation by means of the analysis of chronic therapy with AVDM was 27/100,000 inhabitants (female:male ratio = 2.2:1), with a mean age of 63.5 ± 16.7 years. The risk of developing hypoparathyroidism after neck surgery was 1.5%. While the epidemiological approaches based on disease code and hospital discharge code greatly underestimates the prevalence of hypoparathyroidism, the indirect estimate of this disease through the analysis of prescriptions of AVDM in a European region is in line with the results of studies performed in other regions of the world.


Assuntos
Hipoparatireoidismo/epidemiologia , Hormônio Paratireóideo/uso terapêutico , Vitamina D/uso terapêutico , Idoso , Algoritmos , Calcitriol/uso terapêutico , Doença Crônica , Bases de Dados Factuais , Feminino , Humanos , Hipoparatireoidismo/tratamento farmacológico , Classificação Internacional de Doenças , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Hormônio Paratireóideo/metabolismo , Alta do Paciente , Prevalência , Risco , Vitamina D/metabolismo
4.
Calcif Tissue Int ; 103(2): 151-163, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29511787

RESUMO

Hypoparathyroidism is a rare disease characterized by low serum calcium levels and absent or deficient parathyroid hormone level. Regarding the epidemiology of chronic hypoparathyroidism, there are limited data in Italy and worldwide. Therefore, the purpose of this study was to build a unique database of patients with chronic hypoparathyroidism, derived from the databases of 16 referral centers for endocrinological diseases, affiliated with the Italian Society of Endocrinology, and four centers for endocrine surgery with expertise in hypoparathyroidism, to conduct an epidemiological analysis of chronic hypoparathyroidism in Italy. The study was approved by the Institutional Review Board. A total of 537 patients with chronic hypoparathyroidism were identified. The leading etiology was represented by postsurgical hypoparathyroidism (67.6%), followed by idiopathic hypoparathyroidism (14.6%), syndromic forms of genetic hypoparathyroidism (11%), forms of defective PTH action (5.2%), non-syndromic forms of genetic hypoparathyroidism (0.9%), and, finally, other forms of acquired hypoparathyroidism, due to infiltrative diseases, copper or iron overload, or ionizing radiation exposure (0.7%). This study represents one of the first large-scale epidemiological assessments of chronic hypoparathyroidism based on data collected at medical and/or surgical centers with expertise in hypoparathyroidism in Italy. Although the study presents some limitations, it introduces the possibility of a large-scale national survey, with the final aim of defining not only the prevalence of chronic hypoparathyroidism in Italy, but also standards for clinical and therapeutic approaches.


Assuntos
Bases de Dados Factuais , Hipoparatireoidismo/diagnóstico , Hipoparatireoidismo/epidemiologia , Adolescente , Adulto , Idoso , Cálcio/sangue , Criança , Doença Crônica , Coleta de Dados/métodos , Endocrinologia/métodos , Endocrinologia/organização & administração , Feminino , Humanos , Hipocalcemia/sangue , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Hormônio Paratireóideo/sangue , Fosfatos/sangue , Prevalência , Estudos Retrospectivos , Adulto Jovem
5.
J Orthop Traumatol ; 18(Suppl 1): 3-36, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29058226

RESUMO

BACKGROUND: The Italian Society for Orthopaedics and Traumatology conceived this guidance-which is primarily addressed to Italian orthopedic surgeons, but should also prove useful to other bone specialists and to general practitioners-in order to improve the diagnosis, prevention, and treatment of osteoporosis and its consequences. MATERIALS AND METHODS: Literature reviews by a multidisciplinary team. RESULTS: The following topics are covered: the role of instrumental, metabolic, and genetic evaluations in the diagnosis of osteoporosis; appraisal of the risk of fracture and thresholds for intervention; general strategies for the prevention and treatment of osteoporosis (primary and secondary prevention); the pharmacologic treatment of osteoporosis; the setting and implementation of fracture liaison services for tertiary prevention. Grade A, B, and C recommendations are provided based on the main levels of evidence (1-3). Toolboxes for everyday clinical practice are provided. CONCLUSIONS: The first up-to-date Italian guidelines for the primary, secondary, and tertiary prevention of osteoporosis and osteoporotic fractures are presented.


Assuntos
Osteoporose/terapia , Fraturas por Osteoporose/terapia , Feminino , Humanos , Masculino , Osteoporose/classificação , Osteoporose/diagnóstico , Osteoporose/etiologia , Fraturas por Osteoporose/etiologia , Medição de Risco , Fatores de Risco
6.
Clin Cases Miner Bone Metab ; 14(2): 209-216, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29263736

RESUMO

ROS are highly reactive molecules which consist of a number of diverse chemical species, including radical and non-radical oxygen species. Oxidative stress occurs as a result of an overproduction of ROS not balanced by an adequate level of antioxidants. The natural antioxidants are: thiol compounds among which GSH is the most representative, and non-thiol compounds such as polyphenols, vitamins and also various enzymes. Many diseases have been linked to oxidative stress including bone diseases among which one of the most important is the osteoporosis. The redox state changes are also related to the bone remodeling process which allows the continuous bone regeneration through the coordinated action of bone cells: osteoclasts, osteoblasts and osteocytes. Changes in ROS and/or antioxidant systems seem to be involved in the pathogenesis of bone loss. ROS induce the apoptosis of osteoblasts and osteocytes, and this favours osteoclastogenesis and inhibits the mineralization and osteogenesis. Excessive osteocyte apoptosis correlates with oxidative stress causing an imbalance in favor of osteoclastogenesis which leads to increased turnover of bone remodeling and bone loss. Antioxidants either directly or by counteracting the action of oxidants contribute to activate the differentiation of osteoblasts, mineralization process and the reduction of osteoclast activity. In fact, a marked decrease in plasma antioxidants was found in aged or osteoporotic women. Some evidence shows a link among nutrients, antioxidant intake and bone health. Recent data demonstrate the antioxidant properties of various nutrients and their influence on bone metabolism. Polyphenols and anthocyanins are the most abundant antioxidants in the diet, and nutritional approaches to antioxidant strategies, in animals or selected groups of patients with osteoporosis or inflammatory bone diseases, suggest the antioxidant use in anti-resorptive therapies for the treatment and prevention of bone loss.

7.
Calcif Tissue Int ; 96(4): 335-46, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25660312

RESUMO

Osteocyte apoptosis due to microdamage and/or oxidative stress is related to increased local bone turnover and resorption observed in various bone diseases. Previous data on osteoblasts and osteoclasts have linked reactive oxygen species and antioxidants to bone remodelling. This study performs a comprehensive analysis on the effect of antioxidants such as glutathione (GSH), N-acetylcysteine and lipoic acid (LA) on starvation-induced osteocyte apoptosis and on cytokines involved in bone remodelling such as the receptor activator kB ligand (RANKL), osteoprotegerin (OPG) and sclerostin. For this study, apoptosis was induced by serum starvation in a murine osteocyte-like cell line MLO-Y4; this condition mimics in part osteocyte apoptosis due to microdamage. The results show that starvation-induced apoptosis and expression of RANKL, OPG and sclerostin are redox regulated processes. All antioxidants are able to inhibit the apoptosis due to starvation. They down-regulate the expression and the release of RANKL, the expression of sclerostin and RANKL/OPG ratio, whereas they only in part up-regulate OPG expression. Antioxidants mediate their effect on starvation-induced apoptosis by JNK signalling and on cytokine expression by both JNK and ERK1/2 activities. This study shows the possible involvement of biological antioxidants such as GSH and LA on redox regulated mechanisms related to apoptosis and expression of cytokines involved in bone remodelling. Moreover, it suggests that both JNK and ERK1/2 may be useful biological targets for drugs affecting bone diseases associated with increased oxidative stress.


Assuntos
Acetilcisteína/química , Apoptose , Glutationa/química , Ácido Tióctico/química , Proteínas Adaptadoras de Transdução de Sinal , Animais , Antioxidantes/química , Doenças Ósseas/metabolismo , Remodelação Óssea , Linhagem Celular , Regulação para Baixo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Glicoproteínas/metabolismo , Peróxido de Hidrogênio/química , Peptídeos e Proteínas de Sinalização Intercelular , MAP Quinase Quinase 4/metabolismo , Camundongos , Necrose , Osteócitos/citologia , Osteoprotegerina/metabolismo , Oxirredução , Fosforilação , Ligante RANK/metabolismo
8.
Clin Cases Miner Bone Metab ; 12(2): 151-6, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26604941

RESUMO

Osteoporosis is a metabolic bone disease characterized by loss of bone mass and strength, resulting in increased risk of fractures. It is classically divided into primary (post-menopausal or senile), secondary and idiopathic forms. There are many rare diseases, that cause directly or indirectly osteoporosis. The identification and classification of most of these rare causes of osteoporosis is crucial for the specialists in endocrinology and not, in order to prevent this bone complication and to provide for an early therapy. Several pathogenic mechanisms are involved, including various aspects of bone metabolism such as: decreased bone formation, increased bone resorption, altered calcium, phosphorus and/or vitamin D homeostasis, and abnormal collagen synthesis. In this review, less common forms of primary and secondary osteoporosis are described, specifying, if applicable: genetic causes, epidemiology, clinical features, and pathogenic mechanisms causing osteoporosis. A greater awareness of all rare causes of osteoporosis could reduce the number of cases classified as idiopathic osteoporosis and allow the introduction of appropriate and timely treatments.

9.
Clin Cases Miner Bone Metab ; 12(1): 34-42, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26136794

RESUMO

The Tuscany Region was the first Italian Region to initiate a program for the prevention of hip fractures in over 65 year old. The T.A.R.Ge.T. project "Appropriate treatment of geriatric re-fractures in Tuscany" (Trattamento Appropriato delle Rifratture Geriatriche in Toscana), which is still on-going, includes a preliminary phase (2009-2010) for baseline analysis and education of the participating centers and a 4-year-prospective phase (2011-2014). The monitoring system is performed horizontally analyzing 5 different flows: SDO (Performance Hospitalization), SPF (Pharmaceutical Distribution Dataset), FED (Direct Distribution Dataset), SAA (Registry of Patients), SPA (Specialized Outpatient) flows. In this review will be shown some of the most important results of analyzes of the retrospective phase. Between 2006 and 2011 only 26% of hip fractured patients has being treated with anti-osteoporotic drugs. The percentage of treatment increases 10% after the second fracture. Until 2011 there wasn't in Tuscany a prevention program of bone fragility; patients were treated with specific treatment only in severe cases: this phenomenon implies that mortality and re-fracture are higher on treated patients than in patients who did not have any kind of treatment. The treated patients are the most severe and therefore they have a higher risk of death and re-fracture.

10.
Calcif Tissue Int ; 95(6): 477-94, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25377906

RESUMO

Gaucher disease is a relatively rare metabolic disease caused by the inherited deficiency of the lysosomal enzyme glucocerebrosidase. Gaucher disease affects multiple organs, among which is the skeleton. Bone involvement occurs frequently in Gaucher disease, and is one of its most debilitating features, reducing the quality of life of patients. Bone status is an important consideration for treatment to ameliorate symptoms and reduce the risk of irreversible complications. We have conducted a systematic review of all the various aspects of Gaucher disease, focusing on different skeletal manifestations, pathophysiology of bone alterations, clinical symptoms, and current diagnostic and therapeutic approaches.


Assuntos
Doenças Ósseas/etiologia , Doenças Ósseas/fisiopatologia , Doença de Gaucher/complicações , Doença de Gaucher/fisiopatologia , Humanos
11.
Clin Cases Miner Bone Metab ; 11(1): 36-43, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25002878

RESUMO

OBJECTIVES: Sex steroids are important regulators of bone physiology and play an essential role in the maintenance of bone health throughout the life. Hormonal replacement therapy (HRT) is a treatment commonly used to relieve symptoms and some undesirable consequences of menopause such as osteoporosis. Osteoporosis, characterized by the loss of bone mass and deterioration of microarchitecture with a consequent higher risk of fragility fractures, is under genetic influence. A tetranucleotide (TTTA)n microsatellite repeat polymorphism, at intron 4 of the CYP19 (aromatase) gene, has been previously associated with higher lumbar spine bone mineral density (LS-BMD) and lower risk of spine fracture in postmenopausal women. Moreover, the ERα encoded by the ESR1 gene is another important candidate for the regulation of bone mass of menopause. Moreover prospective analysis from >18.000 subjects at the GENOMOS study indicated that XX homozygotes genotype had a reduced risk of fracture independently from BMD. In the present study, we investigated in postmenopausal Italian women, at baseline and after 1 year of HRT, whether ESR1 and CYP19 gene polymorphisms could affect BMD through different statistical models. METHODS: This study has been performed on 100 post-menopausal Italian women, from a larger group of 250. The study group was administred HRT and LS-BMD was measured at baseline and after 1 year of therapy. Genetic analysis evaluating ESR1 and CYP19 gene polymorphisms was performed. RESULTS: Generalized Linear Models (GLMs) test showed that women with normal LS-BMD at the baseline had a major statistically significant BMD increase of 0.1426 gr/cm(2) (p= 0.0001) with respect to the osteoporotic patients. In addition, subjects with genotype 1 and 2 of CYP19 gene had a lower modification in LS-BMD after 1 year of HRT (0.0837 gr/cm(2) and 0,076 g/cm(2); p=0.0470 and 0,0547 respectively) when compared to genotype 3. No influences of the aromatase genotypes were observed in the variable difference using both Anova and GLMs test. Regarding the ESR1 gene polymorphism, the LS-BMD after 1 year of HRT was influenced by the diagnosis at the baseline and height and ERα genotypes were able to influence difference with statistical significant results with both test. CONCLUSIONS: In the present study, we have demonstrated that CYP19 gene polymorphism is able to influence the effect of 1 year HRT on LS-BMD with no influence on pre-/ and post-/HRT LS-BMD differences. Although ESR1 gene polymorphism is not able to influence the LS-BMD after 1 year HRT, it influences the observed modifications during the year of therapy. These data underlie the complexity of the genetics of the bone mass and its importance in influencing the response to HRT.

12.
Calcif Tissue Int ; 93(5): 462-71, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23836156

RESUMO

Cystic angiomatosis (CA) is a rare disease characterized by multifocal hemangiomatous and/or lymphangiomatous lesions of the skeleton with possible visceral organ involvement. The exact pathogenetic mechanism of the disease is still unknown. We describe a patient affected by CA of bone treated with surgical procedures and subsequently with intravenous aminobisphosphonates for 7 years. During the follow-up progression of lesions, the painful symptoms, markers of bone turnover, computed tomographic examination, and bone mineral density were evaluated. Aminobisphosphonate therapy showed an immediate effectiveness in reducing bone pain, with a significant decrease in circulating bone alkaline phosphatase and stable radiological findings during clinical follow-up. In addition, at baseline, high levels of bone biomarkers and cytokines (osteoprotegerin, osteopontin, and interleukin-6) capable of controlling bone metabolism and angiomatosis were identified. Aminobisphosphonate treatment produced a decrease of all these increased markers. Local cell therapy with bone marrow osteoblast precursors did not produce any measurable clinical improvement. Aminobisphosphonate therapy represents an elective treatment for bone angiomatosis syndromes, but further studies are necessary to understand the molecular basis of these disorders and of their pharmacological treatment.


Assuntos
Angiomatose/complicações , Angiomatose/tratamento farmacológico , Cistos Ósseos/complicações , Cistos Ósseos/tratamento farmacológico , Difosfonatos/uso terapêutico , Humanos , Vértebras Lombares , Masculino , Doenças da Coluna Vertebral/complicações , Doenças da Coluna Vertebral/tratamento farmacológico , Adulto Jovem
13.
Clin Cases Miner Bone Metab ; 10(2): 139-41, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-24133533

RESUMO

Osteonecrosis of the jaw (ONJ) has been recently described after intravenous administration of amino-bisphosphonates and - less frequently - in association with the use of oral bisphosphonates. Bisphosphonate-Related Osteonecrosis of the Jaw (BRONJ) may affect mandible bone (65%), maxilla bone (26%) and rarely (9%) both sites simultaneously. Although causality may never be proven, emerging experimental data have established a strong association between monthly intravenous bisphosphonate administration and ONJ. Current level of evidence does not fully support a cause and effect relationship between the use of oral BPs and ONJ. In this paper, we report a clinical case of BRONJ in a 73 years old woman affected by rheumatoid arthritis (RA) and periodontitis, after three years of treatment with alendronate 70 mg one a week, plus daily calcium and vitamin D. The patient developed a tooth abscess at the lower jaw, accompanied by increased inflammatory markers, that never returned to normal range despite antibiotic therapy, inducing deterioration of joint synovium. The worsening of joint status after the onset of ONJ was reflected by the progressive increase in the number of swollen (SJ) and tender (TJ) joints, by the deterioration of the score DAS 28 (which passed from 5.46 to 7.07), pain (with VAS increasing from 60 to 90), and by a progressively impaired quality of life, as reported using the HAQ score (from 1,25 to 2,5). The patient was switched to antifracture therapy with strontium ranelate and the osteonecrosis was successfully treated with antibiotics, surgical curettage and local ultrasounds.

14.
Antioxidants (Basel) ; 12(2)2023 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-36829932

RESUMO

This review reports in detail the cellular and molecular mechanisms which regulate the bone remodeling process in relation to oxidative stress (OS), inflammatory factors, and estrogen deficiency. OS is considered an important pathogenic factor of osteoporosis, inducing osteocyte apoptosis and varying levels of specific factors, such as receptor activator κB ligand (RANKL), sclerostin, and, according to recent evidence, fibroblast growth factor 23, with consequent impairment of bone remodeling and high bone resorption. Bone loss increases the risk of fragility fractures, and the most commonly used treatments are antiresorptive drugs, followed by anabolic drugs or those with a double effect. In addition, recent data show that natural antioxidants contained in the diet are efficient in preventing and reducing the negative effects of OS on bone remodeling and osteocytes through the involvement of sirtuin type 1 enzyme. Indeed, osteocytes and some of their molecular factors are considered potential biological targets on which antioxidants can act to prevent and reduce bone loss, as well as to promote bone anabolic and regenerative processes by restoring physiological bone remodeling. Several data suggest including antioxidants in novel therapeutic approaches to develop better management strategies for the prevention and treatment of osteoporosis and OS-related bone diseases. In particular, anthocyanins, as well as resveratrol, lycopene, oleuropein, some vitamins, and thiol antioxidants, could have protective and therapeutic anti-osteoporotic effects.

15.
Biochim Biophys Acta ; 1810(4): 446-56, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21256191

RESUMO

BACKGROUND: Sphingosine 1-phosphate (S1P) is a sphingolipid metabolite synthesized after stimulation with growth factors or cytokines. S1P extracellular effects are mediated through specific Gi-protein coupled receptors (GPCRs). Recently, we demonstrated in NIH3T3 fibroblasts stimulated by platelet-derived growth factor (PDGF) or S1P the NADPH oxidase activation and the H(2)O(2) intracellular level increase trough the Gi protein involvement. METHODS: NIH3T3 fibroblast cell cultures were used. Western blot and quantitative analyses by Chemidoc-Quantity-One software were performed. H(2)O(2) level was assayed by fluorescence spectrophotometric analysis, and cell proliferation by counted manually or ELISA kit. RESULTS: This study demonstrates, in NIH 3T3 fibroblasts, a novel redox regulated mechanism of S1P-induced activation of ERK 1/2 related to NADPH oxidase activity and intracellular H(2)O(2) level increase with PDGF receptor tyrosine kinase involvement through a transactivation mechanism. This event is mediated by S1P(1) and S1P(3) receptors by Gi proteins and can contribute to S1P mitogenic signaling. CONCLUSION: These results can be related to mechanisms of cross-talk previously identified between receptor tyrosine kinase, including PDGFreceptor, and several GPCR ligands. GENERAL SIGNIFICANCE: The redox-sensitive ERK1/2 and PDGFr tyrosine kinase activity could be targets for therapies in diseases in which deregulation of intracellular oxidative status and the consequent alteration of S1P and/or PDGF signaling pathway are involved.


Assuntos
Fibroblastos/metabolismo , Lisofosfolipídeos/metabolismo , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , NADPH Oxidases/metabolismo , Receptores do Fator de Crescimento Derivado de Plaquetas/metabolismo , Esfingosina/análogos & derivados , Animais , Proliferação de Células , Fibroblastos/citologia , Peróxido de Hidrogênio/metabolismo , Camundongos , Células NIH 3T3 , Oxirredução , Esfingosina/metabolismo
16.
J Clin Endocrinol Metab ; 107(5): e2087-e2094, 2022 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-34935951

RESUMO

CONTEXT: Hypophosphatasia (HPP) is a rare metabolic disorder caused by deficiency of alkaline phosphatase (ALP) enzyme activity, leading to defective mineralization, due to pathogenic variants of the ALPL gene, encoding the tissue nonspecific alkaline phosphatase (TNSALP) enzyme. Inheritance can be autosomal recessive or autosomal dominant. An abnormal ALPL genetic test enables accurate diagnosis, avoiding the administration of contraindicated antiresorptive drugs that, in patients with HPP, substantially increase the risk of atypical femur fractures (AFFs) and worsen the fracture healing process that is usually already compromised in these patients. OBJECTIVE: Performing ALPL genetic testing to identify rare variants in suspected adult patients with HPP. Comparing frequencies of ALPL common variants in individuals with biochemical and/or clinical signs suggestive of adult HPP and non-HPP controls, and among different clinical subgroups of patients with a clinical suspicion of adult HPP. METHODS: Patients with suspected adult HPP were retrospectively selected for the genetic testing of the ALPL gene. Patients included were from 3 main European Bone Units (Florence, Naples, and Geneva); 106 patients with biochemical and/or clinical signs suggestive of a mild form of HPP were included. RESULTS: Genetic testing led to the identification of a heterozygote rare variant in 2.8% of cases who were initially referred as suspected osteoporosis. The analysis of frequencies of ALPL common variants showed a high prevalence (30.8%) of homozygosity in subjects who developed an AFF, in association with normal serum total ALP activity. CONCLUSION: The results suggest homozygosity of common ALPL variants as a possible genetic mark of risk for these fractures.


Assuntos
Hipofosfatasia , Adulto , Fosfatase Alcalina/genética , Fêmur , Genótipo , Humanos , Hipofosfatasia/diagnóstico , Hipofosfatasia/genética , Mutação , Estudos Retrospectivos
17.
Nat Rev Endocrinol ; 18(8): 473-489, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35578027

RESUMO

The physiological process of biomineralization is complex and deviation from it leads to a variety of diseases. Progress in the past 10 years has enhanced understanding of the genetic, molecular and cellular pathophysiology underlying these disorders; sometimes, this knowledge has both facilitated restoration of health and clarified the very nature of biomineralization as it occurs in humans. In this Review, we consider the principal regulators of mineralization and crystallization, and how dysregulation of these processes can lead to human disease. The knowledge acquired to date and gaps still to be filled are highlighted. The disorders of mineralization discussed comprise a broad spectrum of conditions that encompass bone disorders associated with alterations of mineral quantity and quality, as well as disorders of extraskeletal mineralization (hyperphosphataemic familial tumoural calcinosis). Included are disorders of alkaline phosphatase (hypophosphatasia) and phosphate homeostasis (X-linked hypophosphataemic rickets, fluorosis, rickets and osteomalacia). Furthermore, crystallopathies are covered as well as arterial and renal calcification. This Review discusses the current knowledge of biomineralization derived from basic and clinical research and points to future studies that will lead to new therapeutic approaches for biomineralization disorders.


Assuntos
Hipofosfatasia , Sistema Musculoesquelético , Osteomalacia , Fosfatase Alcalina , Biomineralização , Humanos
18.
G Chir ; 32(3): 142-5, 2011 Mar.
Artigo em Italiano | MEDLINE | ID: mdl-21453595

RESUMO

INTRODUCTION: Purpose of the study was to assess how the introduction of endovascular treatment has affected mortality and morbidity of the traditional surgery for infrarenal abdominal aortic aneurysms (AAA). PATIENTS AND METHODS: From January 2002 to December 2009 we treated 230 patients with AAA (mean age 71.6; 121 male 70.7%); 171 (74.4%) were treated with surgery, 59 (25.6%) underwent to endovascular exclusion .We divided the patients into two groups: Group A, before the beginning of our "endovascular"; Group B, after the beginning of our endovascular experience. A total of 171 patients were treated with traditional surgical intervention, 99 in Group A and 72 in Group B. We evaluated the morbidity and mortality between the two groups by statistical analysis (by Student t test and χ ² test) considering a significant p-value <0.001. RESULTS: e 30-day mortality was 4% respectively in group A and 5.5% in group B (P = not significative, n.s.). The incidence of renal and ischemic peripheral complications was, respectively, 2% and 4% in group A, and 4.1% and 8.3% in group B showing statistical significance (P <.001). There were no documented statistically significant differences between the two groups in terms of cardiac and respiratory complications (P = n.s.). CONCLUSIONS. The results of the traditional surgery for the infrarenal AAA not suitables for endovascular repair suffer from the difficult anatomy of aorto-iliac district. Although the incidence of complications of open surgery is increased, the mortality is similar to anatomical not complicated aneurysms.


Assuntos
Aneurisma da Aorta Abdominal/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Contraindicações , Procedimentos Endovasculares , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Vasculares/métodos , Procedimentos Cirúrgicos Vasculares/mortalidade
19.
Endocrine ; 72(1): 249-259, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33538953

RESUMO

PURPOSE: Chronic hypoparathyroidism is usually treated with calcium and active vitamin D metabolites or analogs, despite the fact that their chronic use can lead to long-term complications. The use of hormone replacement therapy with PTH peptides [teriparatide and rhPTH (1-84)] has therefore been proposed. The main purpose of this study was to investigate the efficacy of teriparatide dose at 20 µg once or twice daily, in order to maintain normocalcemia reducing standard treatment, in adult patients with chronic hypoparathyroidism not well controlled with conventional treatment. METHODS: The study was a Phase III, open-label, non-comparative, clinical investigation (study period: 3 months), at a tertiary care clinical research center. Thirty patients with chronic hypoparathyroidism were screened, and 12 started teriparatide. After the optimization phase (0-4 weeks), calcium and calcitriol supplements were progressively reduced, while teriparatide 20 µg once daily was administered (5-7 weeks), and then could be titrated up to 20 µg twice daily (7-17 weeks). The main outcome measures included serum and urinary biochemical exams and Rand 36-Item Short Form Health Survey. RESULTS: This study showed that teriparatide 20 µg once daily was insufficient to discontinue calcium and calcitriol supplements to maintain normal serum calcium concentrations. Conversely, for more than half of patients treated with teriparatide 20 µg twice daily, calcium and calcitriol administration was avoidable, but in some cases at the expense of serum calcium and phosphate oscillations. CONCLUSIONS: Since intervention trials evaluating the efficacy and safety of teriparatide in hypoparathyroid patients are not yet available, the routine use of this molecule poses some doubts.


Assuntos
Hipoparatireoidismo , Teriparatida , Adulto , Calcitriol/uso terapêutico , Cálcio/uso terapêutico , Terapia de Reposição Hormonal , Humanos , Hipoparatireoidismo/tratamento farmacológico , Hormônio Paratireóideo/uso terapêutico , Teriparatida/uso terapêutico
20.
Nutrients ; 13(12)2021 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-34959778

RESUMO

Several recent studies have demonstrated that the direct precursor of vitamin D3, the calcifediol [25(OH)D3], through the binding to the nuclear vitamin D receptor (VDR), is able to regulate the expression of many genes involved in several cellular processes. Considering that itself may function as a VDR ligand, although with a lower affinity, respect than the active form of vitamin D, we have assumed that 25(OH)D3 by binding the VDR could have a vitamin's D3 activity such as activating non-genomic pathways, and in particular we selected mesenchymal stem cells derived from human adipose tissue (hADMSCs) for the in vitro assessment of the intracellular Ca2+ mobilization in response to 25(OH)D3. Our result reveals the ability of 25(OH)D3 to activate rapid, non-genomic pathways, such as an increase of intracellular Ca2+ levels, similar to what observed with the biologically active form of vitamin D3. hADMSCs loaded with Fluo-4 AM exhibited a rapid and sustained increase in intracellular Ca2+ concentration as a result of exposure to 10-5 M of 25(OH)D3. In this work, we show for the first time the in vitro ability of 25(OH)D3 to induce a rapid increase of intracellular Ca2+ levels in hADMSCs. These findings represent an important step to better understand the non-genomic effects of vitamin D3 and its role in endocrine system.


Assuntos
Calcifediol/farmacocinética , Sinalização do Cálcio/efeitos dos fármacos , Cálcio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Vitaminas/farmacocinética , Humanos , Técnicas In Vitro , Ligantes , Células-Tronco Mesenquimais , Receptores de Calcitriol/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA