Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
1.
Autophagy ; 19(3): 904-925, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-35947488

RESUMEN

Brown adipose tissue (BAT) thermogenesis affects energy balance, and thereby it has the potential to induce weight loss and to prevent obesity. Here, we document a macroautophagic/autophagic-dependent mechanism of peroxisome proliferator-activated receptor gamma (PPARG) activity regulation that induces brown adipose differentiation and thermogenesis and that is mediated by TP53INP2. Disruption of TP53INP2-dependent autophagy reduced brown adipogenesis in cultured cells. In vivo specific-tp53inp2 ablation in brown precursor cells or in adult mice decreased the expression of thermogenic and mature adipocyte genes in BAT. As a result, TP53INP2-deficient mice had reduced UCP1 content in BAT and impaired maximal thermogenic capacity, leading to lipid accumulation and to positive energy balance. Mechanistically, TP53INP2 stimulates PPARG activity and adipogenesis in brown adipose cells by promoting the autophagic degradation of NCOR1, a PPARG co-repressor. Moreover, the modulation of TP53INP2 expression in BAT and in human brown adipocytes suggests that this protein increases PPARG activity during metabolic activation of brown fat. In all, we have identified a novel molecular explanation for the contribution of autophagy to BAT energy metabolism that could facilitate the design of therapeutic strategies against obesity and its metabolic complications.


Asunto(s)
Tejido Adiposo Pardo , PPAR gamma , Ratones , Humanos , Animales , Tejido Adiposo Pardo/metabolismo , PPAR gamma/metabolismo , Autofagia , Obesidad/metabolismo , Termogénesis/genética , Proteínas Nucleares/metabolismo , Co-Represor 1 de Receptor Nuclear/metabolismo
2.
Sci Rep ; 12(1): 1443, 2022 01 27.
Artículo en Inglés | MEDLINE | ID: mdl-35087095

RESUMEN

Extracellular vesicles (EVs) are membrane enclosures released by eukaryotic cells that carry bioactive molecules and serve to modulate biological responses in recipient cells. Both increased EV release and altered EV composition are associated with the development and progression of many pathologies including cancer. Hypoxia, a feature of rapidly growing solid tumours, increases the release of EVs. However, the molecular mechanisms remain unknown. The hypoxia inducible factors (HIFs) are transcription factors that act as major regulators of the cellular adaptations to hypoxia. Here, we investigated the requirement of HIF pathway activation for EV release in Human Embryonic Kidney Cells (HEK293). Time course experiments showed that EV release increased concomitantly with sustained HIF1α and HIF2α activation following the onset of hypoxia. shRNA mediated knock-down of HIF1α but not HIF2α abrogated the effect of hypoxia on EV release, suggesting HIF1α is involved in this process. However, stabilization of HIF proteins in normoxic conditions through: (i) heterologous expression of oxygen insensitive HIF1α or HIF2α mutants in normoxic cells or (ii) chemical inhibition of the prolyl hydroxylase 2 (PHD2) repressor protein, did not increase EV release, suggesting HIF activation alone is not sufficient for this process. Our findings suggest HIF1α plays an important role in the regulation of EV release during hypoxia in HEK293 cells, however other hypoxia triggered mechanisms likely contribute as stabilization of HIF1α alone in normoxia is not sufficient for EV release.


Asunto(s)
Hipoxia de la Célula , Células Epiteliales/metabolismo , Vesículas Extracelulares/metabolismo , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Embrión de Mamíferos , Células Epiteliales/citología , Técnicas de Silenciamiento del Gen , Células HEK293 , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Riñón/citología
3.
Sensors (Basel) ; 21(23)2021 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-34884002

RESUMEN

This work provides a guide to design ultrasonic synthetic aperture systems for non-grid two-dimensional sparse arrays such as spirals or annular segmented arrays. It presents an algorithm that identifies which elements have a more significant impact on the beampattern characteristics and uses this information to reduce the number of signals, the number of emitters and the number of parallel receiver channels involved in the beamforming process. Consequently, we can optimise the 3D synthetic aperture ultrasonic imaging system for a specific sparse array, reducing the computational cost, the hardware requirements and the system complexity. Simulations using a Fermat spiral array and experimental data based on an annular segmented array with 64 elements are used to assess this algorithm.


Asunto(s)
Imagenología Tridimensional , Ultrasonido , Algoritmos , Transductores , Ultrasonografía
4.
Sensors (Basel) ; 21(23)2021 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-34884023

RESUMEN

The analysis of the beampattern is the base of sparse arrays design process. However, in the case of bidimensional arrays, this analysis has a high computational cost, turning the design process into a long and complex task. If the imaging system development is considered a holistic process, the aperture is a sampling grid that must be considered in the spatial domain through the coarray structure. Here, we propose to guide the aperture design process using statistical parameters of the distribution of the weights in the coarray. We have studied three designs of sparse matrix binned arrays with different sparseness degrees. Our results prove that there is a relationship between these parameters and the beampattern, which is valuable and improves the array design process. The proposed methodology reduces the computational cost up to 58 times with respect to the conventional fitness function based on the beampattern analysis.


Asunto(s)
Procesamiento de Imagen Asistido por Computador , Humanos , Ultrasonografía/métodos
5.
Int J Mol Sci ; 22(23)2021 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-34884763

RESUMEN

The adipokine Neuregulin 4 (Nrg4) protects against obesity-induced insulin resistance. Here, we analyze how the downregulation of Nrg4 influences insulin action and the underlying mechanisms in adipocytes. Validated shRNA lentiviral vectors were used to generate scramble (Scr) and Nrg4 knockdown (KD) 3T3-L1 adipocytes. Adipogenesis was unaffected in Nrg4 KD adipocytes, but there was a complete impairment of the insulin-induced 2-deoxyglucose uptake, which was likely the result of reduced insulin receptor and Glut4 protein. Downregulation of Nrg4 enhanced the expression of proinflammatory cytokines. Anti-inflammatory agents recovered the insulin receptor, but not Glut4, content. Proteins enriched in Glut4 storage vesicles such as the insulin-responsive aminopeptidase (IRAP) and Syntaxin-6 as well as TBC1D4, a protein involved in the intracellular retention of Glut4 vesicles, also decreased by Nrg4 KD. Insulin failed to reduce autophagy in Nrg4 KD adipocytes, observed by a minor effect on mTOR phosphorylation, at the time that proteins involved in autophagy such as LC3-II, Rab11, and Clathrin were markedly upregulated. The lysosomal activity inhibitor bafilomycin A1 restored Glut4, IRAP, Syntaxin-6, and TBC1D4 content to those found in control adipocytes. Our study reveals that Nrg4 preserves the insulin responsiveness by preventing inflammation and, in turn, benefits the insulin regulation of autophagy.


Asunto(s)
Autofagia/fisiología , Transportador de Glucosa de Tipo 4/metabolismo , Resistencia a la Insulina/fisiología , Neurregulinas/metabolismo , Receptor de Insulina/biosíntesis , Células 3T3 , Adipocitos/metabolismo , Animales , Línea Celular , Cistinil Aminopeptidasa/biosíntesis , Citocinas/biosíntesis , Desoxiglucosa/metabolismo , Regulación hacia Abajo , Proteínas Activadoras de GTPasa/biosíntesis , Inflamación/patología , Insulina/metabolismo , Ratones , Neurregulinas/biosíntesis , Neurregulinas/genética , Proteínas Qa-SNARE/biosíntesis , Interferencia de ARN , ARN Interferente Pequeño/genética
6.
Int J Surg Case Rep ; 86: 106307, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34392017

RESUMEN

INTRODUCTION: CoV-2 infection generates a pro-inflammatory state, which conditions the formation of thrombi that can affect any system. Multi-organ dysfunction is a cause of death, mesenteric ischemia in COVID 2019 patients reported is 1.9-4%. DESCRIPTION OF THE CASE: We present the case of a 73-year-old male patient who started with severe SARS-CoV-2 and arterial-type intestinal ischemia, necrosis of 3 m of the small intestine, based on SCARE 2020 guide. DISCUSSION: Complications secondary to thrombosis are as follows; myocardial infarction 1.1%, ischemic cerebral events, 2.5-3.7%, microvascular thrombosis including mesenteric ischemia in less than 1% of cases. In patients with mesenteric ischemia the reported postoperative mortality is 23.8% of patients especially during the first 30 days. CONCLUSION: Intestinal thrombosis in patients with SARS-CoV-2 increases mortality.

7.
Int J Surg Case Rep ; 84: 106091, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34153698

RESUMEN

INTRODUCTION: Inflammatory myofibroblastic tumors are neoplasms that occur infrequently, mainly affects children and young adults. It is an intermediate grade fibrotic multinodular neoplasm. DESCRIPTION OF THE CASE: We present the case of a 47-year-old female patient, who underwent emergency umbilical hernioplasty, later developed intestinal obstruction secondary to an inflammatory myofibroblastic tumor. DISCUSSION: In 1939 Brunn described it for the first time, later in 1954 Umiker named it "Inflammatory Myofibroblastic Tumor". The symptoms are nonspecific. In 15 to 40% of patients they are asymptomatic. Cells positive for actin, smooth muscle, vimentin and desmin, in 3367% of cases the cells are positive for ALK, which is present in some malignant lesions. The recommended treatment is radical resection. CONCLUSION: The diagnosis is established by histopathological study, surgery is the cornerstone of treatment.

8.
Materials (Basel) ; 14(6)2021 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-33805742

RESUMEN

Glass fibre is the most widely used material for reinforcing thermoplastic matrices presently and its use continues to grow. A significant disadvantage of glass fibre, however, is its impact on the environment, in particular, due to the fact that glass fibre-reinforced composite materials are difficult to recycle. Polyamide 6 is an engineering plastic frequently used as a matrix for high-mechanical performance composites. Producing polyamide monomer requires the use of a large amount of energy and can also pose harmful environmental impacts. Consequently, glass fibre-reinforced Polyamide 6 composites cannot be considered environmentally friendly. In this work, we assessed the performance of a road cycling pedal body consisting of a composite of natural Polyamide 11 reinforced with lignocellulosic fibres from stone-ground wood, as an alternative to the conventional glass fibre-reinforced Polyamide 6 composite (the most common material used for recreational purposes). We developed a 3D model of a pedal with a geometry based on a combination of two existing commercial choices and used it to perform three finite-element tests in order to assess its strength under highly demanding static and cyclic conditions. A supplementary life cycle analysis of the pedal was also performed to determine the ecological impact. Based on the results of the simulation tests, the pedal is considered to be mechanically viable and has a significantly lower environmental impact than fully synthetic composites.

9.
Front Endocrinol (Lausanne) ; 12: 786952, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34975758

RESUMEN

Aims: To test the hypothesis that adipose tissue gene expression patterns would be affected by metabolic surgery and we aimed to identify genes and metabolic pathways as well as metabolites correlating with metabolic changes following metabolic surgery. Materials and Methods: This observational study was conducted at the Obesity Unit at the Catholic University Hospital of the Sacred Heart in Rome, Italy. Fifteen patients, of which six patients underwent Roux-en-Y gastric bypass and nine patients underwent biliopancreatic diversion, were included. The participants underwent an oral glucose tolerance test and a hyperinsulinemic euglycemic clamp. Small polar metabolites were analyzed with a two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC-TOFMS). Gene expression analysis of genes related to metabolism of amino acids and fatty acids were analyzed in subcutaneous adipose tissue. All procedures were performed at study start and at follow-up (after 185.3 ± 72.9 days). Results: Twelve metabolites were significantly changed after metabolic surgery. Six metabolites were identified as 3-indoleacetic acid, 2-hydroxybutyric acid, valine, glutamic acid, 4-hydroxybenzeneacetic acid and alpha-tocopherol. The branched chain amino acids displayed a significant decrease together with a decrease in BCAT1 adipose tissue mRNA levels. Changes in the identified metabolites were associated to changes in lipid, insulin and glucose levels. Conclusions: Our study has identified metabolites and metabolic pathways that are altered by metabolic surgery and may be used as biomarkers for metabolic improvement.


Asunto(s)
Tejido Adiposo/metabolismo , Derivación Gástrica , Glucosa/metabolismo , Metabolismo de los Lípidos/genética , Obesidad/cirugía , Tejido Adiposo/química , Aminoácidos/metabolismo , Ácidos Grasos/metabolismo , Femenino , Derivación Gástrica/métodos , Perfilación de la Expresión Génica , Técnica de Clampeo de la Glucosa , Homeostasis/genética , Humanos , Italia , Masculino , Redes y Vías Metabólicas/genética , Persona de Mediana Edad , Obesidad/metabolismo , ARN Mensajero/análisis , Transaminasas/genética
10.
Artículo en Inglés | MEDLINE | ID: mdl-33259295

RESUMEN

A methodology for the assessment of cell concentration, in the range 5-100 cells/ [Formula: see text], suitable for in vivo analysis of serous body fluids is presented in this work. This methodology is based on the quantitative analysis of ultrasound images obtained from cell suspensions and considers applicability criteria, such as short analysis times, moderate frequency, and absolute concentration estimation, all necessary to deal with the variability of tissues among different patients. Numerical simulations provided the framework to analyze the impact of echo overlapping and the polydispersion of scatterer sizes on the cell concentration estimation. The cell concentration range that can be analyzed as a function of the transducer and emitted waveform used was also discussed. Experiments were conducted to evaluate the performance of the method using 7- [Formula: see text] and 12- [Formula: see text] polystyrene particles in water suspensions in the 5-100 particles/ [Formula: see text] range. A single scanning focused transducer working at a central frequency of 20 MHz was used to obtain ultrasound images. The method proposed to estimate the concentration proved to be robust for different particle sizes and variations of gain acquisition settings. The effect of tissues placed in the ultrasound path between the probe and the sample was also investigated using 3-mm-thick tissue mimics. Under this situation, the algorithm was robust for the concentration analysis of 12 [Formula: see text] particle suspensions, yet significant deviations were obtained for the smallest particles.


Asunto(s)
Algoritmos , Líquidos Corporales , Humanos , Ultrasonografía
11.
Cell Cycle ; 18(13): 1435-1445, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31135269

RESUMEN

Autophagy plays a key role in cellular homeostasis since it allows optimal cellular functioning and provides energy under conditions of stress. Initial is revealed that alterations of macroautophagy disturb adipogenic differentiation in cultured cells, and in mice, leading to a drastic reduction of adipose tissue depots. Nevertheless, more recent studies indicate that autophagy participates in the control of adipose tissue biology in a more complex manner. The protein TP53INP2 activates the formation of autophagosomes by binding to ATG8 proteins such as LC3 or GATE16, and its genetic elimination reduces but does not cancel this activity. TP53INP2 deficiency increases adipogenic differentiation and induces a gain in adiposity in the mouse. At the cellular level, TP53INP2 promotes the sequestration of the regulatory protein GSK3ß in multivesicular bodies (MVBs) by a process that involves autophagic activity and the participation of the endosomal sorting complexes required for transport (ESCRT) machinery. Through this mechanism, TP53INP2 stabilizes and activates ß-catenin, which in turn triggers the inhibition of adipogenesis. In summary, autophagic pathways provide a whole set of mechanisms that may regulate in an opposite way the biology of adipose tissue, and consequently, have a variable impact on the whole body adiposity. This concept may be extensible to other cell types.


Asunto(s)
Tejido Adiposo/fisiología , Autofagia/fisiología , Adipogénesis/fisiología , Adiposidad/fisiología , Animales , Diferenciación Celular/fisiología , Humanos , Cuerpos Multivesiculares/fisiología
12.
Artículo en Inglés | MEDLINE | ID: mdl-29994765

RESUMEN

Using a generic model of how active array imaging systems operate, a formal definition of the image as a projection of the reflected wave field onto the wave field emitted to probe the medium is proposed. This definition is applied to the case of imaging in homogeneous and isotropic media to which, by using the frequency-domain solution of the wave equation, the relationship between the calculated image, the emitted and received signals, the positions of the transducers, the speed of the waves used, and the reflectivity of the medium is shown at each point. Then, a general algorithm for the formation of images of a region in this kind of media is derived. Finally, using real and simulated ultrasound signals, images obtained with the proposed signal projection method are compared with those produced by the "de facto" standard delay and sum-based algorithms.

13.
EMBO J ; 37(10)2018 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-29632021

RESUMEN

Opa1 participates in inner mitochondrial membrane fusion and cristae morphogenesis. Here, we show that muscle-specific Opa1 ablation causes reduced muscle fiber size, dysfunctional mitochondria, enhanced Fgf21, and muscle inflammation characterized by NF-κB activation, and enhanced expression of pro-inflammatory genes. Chronic sodium salicylate treatment ameliorated muscle alterations and reduced the muscle expression of Fgf21. Muscle inflammation was an early event during the progression of the disease and occurred before macrophage infiltration, indicating that it is a primary response to Opa1 deficiency. Moreover, Opa1 repression in muscle cells also resulted in NF-κB activation and inflammation in the absence of necrosis and/or apoptosis, thereby revealing that the activation is a cell-autonomous process and independent of cell death. The effects of Opa1 deficiency on the expression NF-κB target genes and inflammation were absent upon mitochondrial DNA depletion. Under Opa1 deficiency, blockage or repression of TLR9 prevented NF-κB activation and inflammation. Taken together, our results reveal that Opa1 deficiency in muscle causes initial mitochondrial alterations that lead to TLR9 activation, and inflammation, which contributes to enhanced Fgf21 expression and to growth impairment.


Asunto(s)
ADN Mitocondrial/genética , GTP Fosfohidrolasas/fisiología , Inflamación/etiología , Músculo Esquelético/patología , Enfermedades Musculares/etiología , Receptor Toll-Like 9/metabolismo , Animales , Apoptosis , Células Cultivadas , Citocinas/metabolismo , Femenino , Inflamación/metabolismo , Inflamación/patología , Masculino , Ratones Noqueados , Músculo Esquelético/inmunología , Enfermedades Musculares/metabolismo , Enfermedades Musculares/patología , Necrosis , Regeneración , Receptor Toll-Like 9/genética
14.
Nat Cell Biol ; 20(4): 443-454, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29593329

RESUMEN

Excessive fat accumulation is a major risk factor for the development of type 2 diabetes mellitus and other common conditions, including cardiovascular disease and certain types of cancer. Here, we identify a mechanism that regulates adiposity based on the activator of autophagy TP53INP2. We report that TP53INP2 is a negative regulator of adipogenesis in human and mouse preadipocytes. In keeping with this, TP53INP2 ablation in mice caused enhanced adiposity, which was characterized by greater cellularity of subcutaneous adipose tissue and increased expression of master adipogenic genes. TP53INP2 modulates adipogenesis through autophagy-dependent sequestration of GSK3ß into late endosomes. GSK3ß sequestration was also dependent on ESCRT activity. As a result, TP53INP2 promotes greater ß-catenin levels and induces the transcriptional activity of TCF/LEF transcription factors. These results demonstrate a link between autophagy, sequestration of GSK3ß into late endosomes and inhibition of adipogenesis in vivo.


Asunto(s)
Adipocitos/enzimología , Adipogénesis , Tejido Adiposo/enzimología , Adiposidad , Autofagia , Glucógeno Sintasa Quinasa 3 beta/metabolismo , Proteínas Nucleares/metabolismo , beta Catenina/metabolismo , Células 3T3-L1 , Adipocitos/patología , Tejido Adiposo/patología , Adulto , Animales , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Endosomas/enzimología , Femenino , Glucógeno Sintasa Quinasa 3 beta/genética , Humanos , Hiperplasia , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Persona de Mediana Edad , Proteínas Nucleares/genética , Transporte de Proteínas , España , Suecia , Factores de Transcripción TCF/genética , Factores de Transcripción TCF/metabolismo , Factores de Tiempo , Activación Transcripcional , Vía de Señalización Wnt , beta Catenina/genética
15.
J Clin Sleep Med ; 11(11): 1289-98, 2015 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-26094931

RESUMEN

STUDY OBJECTIVES: To develop the Barcelona Sleepiness Index (BSI), an interviewer-administered instrument for assessing excessive daytime sleepiness (EDS) in sleep-disordered breathing (SDB) that correlates well with objective measures of EDS and which is sensitive to change with treatment. METHODS: (1) Generation of a preliminary item list: Fifty-three consecutive SDB patients complaining of EDS and their bed partners were interviewed using a focus group methodology to generate a list of situations prone to cause sleepiness. Sixty different consecutive SDB patients were then evaluated using cognitive interviews to refine this list. (2) Construct validity: The maintenance of wakefulness test (MWT), the multiple sleep latency test (MSLT) and the sustained attention to response task (SART) test were used in an additional 98 consecutive SDB patients with and without EDS. The item combination that best correlated with the objective tests constituted the BSI. Cutoff values were determined to differentiate between patients with and without EDS. (3) Sensitivity to change: Thirty patients requiring continuous positive airway pressure (CPAP) were evaluated after satisfactory treatment. RESULTS: A combination of two items, "in the morning, when relaxing" and "in the afternoon, standing inactive, in a public place," presented the highest correlations with the MWT (r: -0.50, p < 0.001), the MSLT (r: -0.21, p = 0.07), and the SART (r: 0.27, p < 0.02) and constituted the BSI. The BSI significantly correlated with oxyhemoglobin saturation measures (nadir SpO2: r: -0.28, p = 0.01; CT 85: r: 0.23, p = 0.04) and showed a high sensitivity to change with CPAP treatment (t: 3.4, p = 0.002). A score of 2 or more identified patients with objective EDS (sensitivity = 64.9%, specificity = 72.1%). CONCLUSION: The Barcelona Sleepiness Index is a simple, brief instrument for measuring subjective EDS in SDB.


Asunto(s)
Trastornos de Somnolencia Excesiva/complicaciones , Trastornos de Somnolencia Excesiva/diagnóstico , Síndromes de la Apnea del Sueño/complicaciones , Encuestas y Cuestionarios/normas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Autoinforme , Sensibilidad y Especificidad , España
16.
J Diabetes Res ; 2013: 162846, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23984429

RESUMEN

Parathyroid hormone-related protein (PTHrP) and its receptor type 1 (PTH1R) are extensively expressed in the kidney, where they are able to modulate renal function. Renal PTHrP is known to be overexpressed in acute renal injury. Recently, we hypothesized that PTHrP involvement in the mechanisms of renal injury might not be limited to conditions with predominant damage of the renal tubulointerstitium and might be extended to glomerular diseases, such as diabetic nephropathy (DN). In experimental DN, the overexpression of both PTHrP and the PTH1R contributes to the development of renal hypertrophy as well as proteinuria. More recent data have shown, for the first time, that PTHrP is upregulated in the kidney from patients with DN. Collectively, animal and human studies have shown that PTHrP acts as an important mediator of diabetic renal cell hypertrophy by a mechanism which involves the modulation of cell cycle regulatory proteins and TGF- ß 1. Furthermore, angiotensin II (Ang II), a critical factor in the progression of renal injury, appears to be responsible for PTHrP upregulation in these conditions. These findings provide novel insights into the well-known protective effects of Ang II antagonists in renal diseases, paving the way for new therapeutic approaches.


Asunto(s)
Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Nefropatías Diabéticas/etiología , Proteína Relacionada con la Hormona Paratiroidea/metabolismo , Animales , Nefropatías Diabéticas/metabolismo , Humanos , Riñón/metabolismo , Receptor de Hormona Paratiroídea Tipo 1/metabolismo
17.
J Cell Physiol ; 227(5): 1980-7, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-21732369

RESUMEN

Hypertrophy of human mesangial cells (HMC) is among the earliest characteristics in patients with diabetic nephropathy (DN). Recently, we observed the upregulation of parathyroid hormone (PTH)-related protein (PTHrP) in experimental DN, associated with renal hypertrophy. Herein, we first examined whether PTHrP was overexpressed in human DN, and next assessed the putative role of this protein on high glucose (HG)-induced HMC hypertrophy. As previously found in mice, kidneys from diabetic patients showed an increased tubular and glomerular immunostaining for PTHrP. In HMC, HG medium increased PTHrP protein expression associated with the development of hypertrophy as assessed by cell protein content. This effect was also induced by PTHrP(1-36). HG and PTHrP(1-36)-induced hypertrophy were associated with an increase in cyclin D1 and p27Kip1 protein expression, a decreased cyclin E expression, and the prevention of cyclin E/cdk2 complex activation. Both PTHrP neutralizing antiserum (α-PTHrP) and the PTH/PTHrP receptor antagonist (JB4250) were able to abolish HG induction of hypertrophy, the aforementioned changes in cell cycle proteins, and also TGF-ß1 up-regulation. Moreover, the capability of both HG and PTHrP(1-36) to induce HMC hypertrophy was abolished by α-TGFß1. These data show for the first time that PTHrP is upregulated in the kidney of patients with DN. Our findings also demonstrate that PTHrP acts as an important mediator of HG-induced HMC hypertrophy by modulating cell cycle regulatory proteins and TGF-ß1.


Asunto(s)
Nefropatías Diabéticas/metabolismo , Nefropatías Diabéticas/patología , Riñón/metabolismo , Riñón/patología , Células Mesangiales/metabolismo , Células Mesangiales/patología , Proteína Relacionada con la Hormona Paratiroidea/metabolismo , Animales , Proliferación Celular , Células Cultivadas , Ciclina D1/genética , Ciclina D1/metabolismo , Ciclina E/genética , Ciclina E/metabolismo , Quinasa 2 Dependiente de la Ciclina/genética , Quinasa 2 Dependiente de la Ciclina/metabolismo , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/genética , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/metabolismo , Femenino , Humanos , Hipertrofia/metabolismo , Hipertrofia/patología , Riñón/citología , Masculino , Células Mesangiales/citología , Ratones , Persona de Mediana Edad , Proteína Relacionada con la Hormona Paratiroidea/genética , Factor de Crecimiento Transformador beta1/metabolismo
18.
Nephrol Dial Transplant ; 25(8): 2447-57, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20200004

RESUMEN

BACKGROUND: Hypertrophy of podocytes is characteristic in diabetic nephropathy (DN). Previously, we observed the upregulation of parathyroid hormone-related protein (PTHrP) and its receptor PTH1R, in experimental DN, associated with renal hypertrophy. Herein, we test the hypothesis that PTHrP participates in the mechanism of high glucose (HG)-induced podocyte hypertrophy. METHODS: On mouse podocytes, hypertrophy was assessed by protein content/cell and [H(3)]leucine incorporation. Podocytes were stimulated with HG (25 mM), PTHrP(1-36) (100 nM), angiotensin II (AngII) (100 nM) or TGF-beta(1) (5 ng/mL) in the presence or absence of PTHrP-neutralizing antibodies (alpha-PTHrP), the PTH1R antagonist JB4250 (10 microM), PTHrP silencer RNA (siRNA) or TGF-beta(1) siRNA. Protein expression was analysed by western blot and immunohistochemistry. RESULTS: HG-induced hypertrophy was abolished in the presence of either alpha-PTHrP or PTHrP siRNA. This effect was associated with an inhibition of the upregulation of TGF-beta(1) and p27(Kip1). JB4250 also inhibited HG-induced p27(Kip1) upregulation. Interestingly, whilst HG and AngII were unable to stimulate the expression of p27(Kip1) on PTHrP siRNA-transfected podocytes, TGF-beta(1) was still able to upregulate p27(Kip1) in these cells. Moreover, HG and PTHrP-induced hypertrophy as well as p27(Kip1) upregulation were abolished on TGF-beta(1) siRNA-transfected podocytes. Furthermore, the glomeruli of transgenic PTHrP-overexpressing mice showed a constitutive overexpression of TGF-beta(1) and p27(Kip1) to a degree similar to that of diabetic animals. CONCLUSIONS: PTHrP seems to participate in the hypertrophic signalling triggered by HG. In this condition, AngII induces the upregulation of PTHrP, which might induce the expression of TGF-beta(1) and p27(Kip1). These findings provide new insights into the protective effects of AngII antagonists in DN, opening new paths for intervention.


Asunto(s)
Inhibidor p27 de las Quinasas Dependientes de la Ciclina/metabolismo , Nefropatías Diabéticas/metabolismo , Proteína Relacionada con la Hormona Paratiroidea/metabolismo , Podocitos/metabolismo , Podocitos/patología , Factor de Crecimiento Transformador beta1/metabolismo , Angiotensina II/antagonistas & inhibidores , Angiotensina II/farmacología , Animales , Células Cultivadas , Nefropatías Diabéticas/patología , Modelos Animales de Enfermedad , Glucosa/efectos adversos , Hipertrofia/metabolismo , Hipertrofia/patología , Ratones , Proteína Relacionada con la Hormona Paratiroidea/farmacología , Fragmentos de Péptidos/farmacología , Podocitos/efectos de los fármacos , Transducción de Señal/fisiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...