976 resultados para platelet-derived growth factor-beta receptor (PDGFR-beta)
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Purpose: The aversive nature of regenerative milieu is the main problem related to the failure of neuronal restoration in the injured spinal cord which however might be addressed with an adequate repair intervention. We evaluated whether glial cell line-derived neurotrophic factor (GDNF) may increase the ability of sciatic nerve graft, placed in a gap promoted by complete transections of the spinal cord, to enhance motor recovery and local fiber growth. Methods: Rats received a 4 mm-long gap at low thoracic level and were repaired with a fragment of the sciatic nerve. GDNF was added (NERVE+GDNF) or not to the grafts (NERVE-GDNF). Motor behavior score (BBB) and sensorimotor tests-linked to the combined behavior score (CBS), which indicate the degree of the motor improvement and the percentage of functional deficit, respectively, and also the spontaneous motor behavior in an open field by means of an infrared motion sensor activity monitor were analyzed. At the end of the third month post surgery, the tissue composed by the graft and the adjacent regions of the spinal cord was removed and submitted to the immunohistochemistry of the neurofilament-200 (NF-200), growth associated protein-43 (GAP-43), microtubule associated protein-2 (MAP-2), 5-hidroxytryptamine (serotonin, 5-HT) and calcitonin gene related peptide (CGRP). The immunoreactive fibers were quantified at the epicenter of the graft by means of stereological procedures. Results: Higher BBB and lower CBS levels (p < 0.001) were found in NERVE+GDNF rats. GDNF added to the graft increased the levels of individual sensorimotor tests mainly at the third month. Analysis of the spontaneous motor behavior showed decreases in the time and number of small movement events by the third month without changes in time and number of large movement events in the NERVE+GDNF rats. Immunoreactive fibers were encountered inside the grafts and higher amounts of NF-200, GAP-43 and MAP-2 fibers were found in the epicenter of the graft when GDNF was added. A small amount of descending 5-HT fibers was seen reentering in the adjacent caudal levels of the spinal cords which were grafted in the presence of GDNF, event that has not occurred without the neurotrophic factor. GDNF in the graft also led to a large amount of MAP-2 perikarya and fibers in the caudal levels of the cord gray matter, as determined by the microdensitometric image analysis. Conclusions: GDNF added to the nerve graft favored the motor recovery, local neuronal fiber growth and neuroplasticity in the adjacent spinal cord.
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Objective: To analyze vascular density and immunolocalization of angiogenic vascular endothelial growth factor (VEGF) and its receptor Flk-1 in the proliferative and secretory eutopic human endometrium. and in three different sites of endometriosis: the ovary, bladder, and rectum. Design: Prospective study. Setting: University hospital. Patient(s): Thirty women with endometriosis (10 ovarian, 1.0 bladder, 10 rectal) and 32 control women (10 proliferative endometrium, 10 secretory endometrium, 4 normal ovary, 4 normal bladder, 4 normal rectum). Intervention(s): Normal endometrial samples were obtained from women during laparoscopic ablation of subserous myoma, and biopsy specimens of endometriosis were obtained from patients undergoing surgery for the diagnosis and treatment of endometriosis. Normal tissues of ovary, bladder, and rectum were obtained from these organs beside the lesions of endometriosis. Main Outcome Measure(S): Blood vessels were quantified according to the number of von Willebrand factor-positive endothelial cells. The VEGF and Flk-1 distribution were evaluated semiquantitatively by immunohistochemical staining. Result(s): More blood vessels were found in cases of endometriosis, particularly rectal endometriosis, compared with the respective control samples and with the eutopic endometrium, and they were localized in endometrial stroma around the glands. The VEGF and Flk-1 expression levels were also higher in cases of endometriosis, especially rectal endometriosis. Conclusion(s): Vascularization and VEGF and Flk-1 expression are significantly higher in deeply infiltrating endometriosis affecting the rectum, reinforcing the hypothesis that antiangiogenesis therapy may constitute a new modality of treatment, especially in cases of deep endometriosis involving the rectum.
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Arginase activity has been related to leishmaniasis development, thus we studied the constitutive and insulin-like growth factor (IGF) I-induced arginase activity of Leishmania (Viannia) braziliensis isolates from patients with different clinical forms of American tegumentary leishmaniasis (ATL). Isolates from mucosal leishmaniasis presented higher basal levels of arginase activity than isolates from other clinical forms of ATL. Isolates from disseminated leishmaniasis that present mucosal lesion in some cases reached the arginase activity similar to that of isolates from mucosal leishmaniasis upon IGF-I stimulation. Differences in arginase activity may influence disease outcomes such as evolution to mucosal lesion in patients with L (V.) braziliensis infection. (C) 2010 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.
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Jorge Lobo`s disease, or lacaziosis, is a chronic deep mycosis that clinically manifests as solid, variable-sized nodular parakeloidal lesions. Few studies have characterized the in situ cellular and humoral immune response, especially the involvement of cytokines with immunosuppressive effects such as TGF-beta. The objective this paper was to analyze the expression of TGF-beta in cutaneous lesions in lacaziosis and investigate its importance in the etiopathogy of the disease. The results indicate that the abundance of collagen bands, together with weak immunolabeling for CD68 seen in macrophages, indicates a concomitant effect of TGF-beta inhibiting macrophages and inducing fibrosis, which is responsible for the keloid aspect frequently acquired by these lesions. Finally, the evolution of the infection supports the hypothesis that TGF-beta plays a fundamental role in the etiopathology of Lacazia loboi infection, either by inhibiting the cellular immune response mainly mediated by macrophages or by inducing fibrosis. Further studies are necessary to better characterize the phenotype of the inflammatory infiltrate as well as the participation of other cytokines and growth factors in the tissue response of the host in Jorge Lobo`s disease. (C) 2008 Published by Elsevier Inc.
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Context: Abnormal FGFR4 expression has been detected in pituitary tumors, especially in larger and invasive adenomas. In addition, the FGFR4 functional polymorphism G388R has been associated with poor outcome in several human malignancies. Then, we hypothesized that FGFR4 expression and genotype could be markers of adverse outcome of Cushing`s disease after transsphenoidal surgery. Objectives: The objective was to investigate whether there is an association between the postoperative outcome of Cushing`s disease (remission/recurrence) and the FGFR4 G388R genotype or the FGFR4 expression in corticotrophinomas. Design and Patients: Clinical, hormonal, and pathological data of 76 patients who underwent the first transsphenoidal surgery were retrospectively reviewed. All patients were genotyped for G388R polymorphism. FGFR4 expression was assessed by real-time PCR in 18 corticotrophinomas. Main Outcome Measures: The outcome measures included the FGFR4 G388R genotype and FGFR4 expression in postoperative remission and recurrence of Cushing`s disease. Results: Homozygosis for FGFR4 glycine (Gly(388)) allele was associated with reduced disease-free survival, in the univariate analysis (hazard ratio of 6.91; 95% confidence interval of 1.14-11.26; P = 0.028). Male gender (P = 0.036), lack of pathology confirmation (P = 0.009), and cortisol levels more than 2 mu g/dl in the early postoperative period (P < 0.001) were also significant predictors of Cushing`s disease recurrence in the univariate analysis. FGFR4 overexpression was found in 44% of the corticotrophinomas, and it was associated with lower postoperative remission rate (P = 0.009). Conclusions: Our data suggest that homozygosis for FGFR4 Gly(388) allele and FGFR4 overexpression are associated with higher frequency of postoperative recurrence and persistence of Cushing`s disease, respectively. (J Clin Endocrinol Metab 95: E271-E279, 2010)
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Myocardial hypertrophy and dysfunction occur in response to excessive catecholaminergic drive. Adverse cardiac remodelling is associated with activation of proinflammatory cytokines in the myocardium. To test the hypothesis that exercise training can prevent myocardial dysfunction and production of proinflammatory cytokines induced by beta-adrenergic hyperactivity, male Wistar rats were assigned to one of the following four groups: sedentary non-treated (Con); sedentary isoprenaline treated (Iso); exercised non-treated (Ex); and exercised plus isoprenaline (Iso+Ex). Echocardiography, haemodynamic measurements and isolated papillary muscle were used for functional evaluations. Real-time RT-PCR and Western blot were used to quantify tumour necrosis factor alpha, interleukin-6, interleukin-10 and transforming growth factor beta(1) (TGF-beta(1)) in the tissue. NF-kappa B expression in the nucleus was evaluated by immunohistochemical staining. The Iso rats showed a concentric hypertrophy of the left ventricle (LV). These animals exhibited marked increases in LV end-diastolic pressure and impaired myocardial performance in vitro, with a reduction in the developed tension and maximal rate of tension increase and decrease, as well as worsened recruitment of the Frank-Starling mechanism. Both gene and protein levels of tumour necrosis factor alpha and interleukin-6, as well as TGF-beta(1) mRNA, were increased. In addition, the NF-kappa B expression in the Iso group was significantly raised. In the Iso+Ex group, the exercise training had the following effects: (1) it prevented LV hypertrophy; (ii) it improved myocardial contractility; (3) it avoided the increase of proinflammatory cytokines and improved interleukin-10 levels; and (4) it attenuated the increase of TGF-beta(1) mRNA. Thus, exercise training in a model of beta-adrenergic hyperactivity can avoid the adverse remodelling of the LV and inhibit inflammatory cytokines. Moreover, the cardioprotection is related to beneficial effects on myocardial performance.
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Background and objective: Vascular endothelial growth factor (VEGF) is known to increase vascular permeability and promote angiogenesis. It is expressed in most types of pleural effusions. However, the exact role of VEGF in the development of pleural effusions has yet to be determined. The anti-VEGF mAb, bevacizumab, has been used in the treatment of cancer to reduce local angiogenesis and tumour progression. This study describes the acute effects of VEGF blockade on the expression of inflammatory cytokines and pleural fluid accumulation. Methods: One hundred and twelve New Zealand rabbits received intrapleural injections of either talc or silver nitrate. In each group, half the animals received an intravenous injection of bevacizumab, 30 min before the intrapleural agent was administered. Five animals from each subgroup were sacrificed 1, 2, 3, 4 or 7 days after the procedure. Twelve rabbits were used to evaluate vascular permeability using Evans`s blue dye. Pleural fluid volume and cytokines were quantified. Results: Animals pretreated with anti-VEGF antibody showed significant reductions in pleural fluid volumes after talc or silver nitrate injection. IL-8 levels, vascular permeability and macroscopic pleural adhesion scores were also reduced in the groups that received bevacizumab. Conclusions: This study showed that bevacizumab interferes in the acute phase of pleural inflammation induced by silver nitrate or talc, reinforcing the role of VEGF as a key mediator in the production of pleural effusions. The results also suggest that bevacizumab should probably be avoided in patients requiring pleurodesis.
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P>Objective Congenital hypogonadotropic hypogonadism with anosmia (Kallmann syndrome) or with normal sense of smell is a heterogeneous genetic disorder caused by defects in the synthesis, secretion and action of gonadotrophin-releasing hormone (GnRH). Mutations involving autosomal genes have been identified in approximately 30% of all cases of hypogonadotropic hypogonadism. However, most studies that screened patients with hypogonadotropic hypogonadism for gene mutations did not include gene dosage methodologies. Therefore, it remains to be determined whether patients without detected point mutation carried a heterozygous deletion of one or more exons. Measurements We used the multiplex ligation-dependent probe amplification (MLPA) assay to evaluate the potential contribution of heterozygous deletions of FGFR1, GnRH1, GnRHR, GPR54 and NELF genes in the aetiology of GnRH deficiency. Patients We studied a mutation-negative cohort of 135 patients, 80 with Kallmann syndrome and 55 with normosmic hypogonadotropic hypogonadism. Results One large heterozygous deletion involving all FGFR1 exons was identified in a female patient with sporadic normosmic hypogonadotropic hypogonadism and mild dimorphisms as ogival palate and cavus foot. FGFR1 hemizygosity was confirmed by gene dosage with comparative multiplex and real-time PCRs. Conclusions FGFR1 or other autosomal gene deletion is a possible but very rare event and does not account for a significant number of sporadic or inherited cases of isolated GnRH deficiency.
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IgA nephropathy (IgAN) is a kidney disease with a varying renal prognosis. Recently, many studies have demonstrated that renal alpha-smooth muscle actin (alpha-SMA) and transforming growth factor (TGF-beta 1) expression, as well interstitial mast cell infiltrates could represent a prognostic marker in several renal diseases. The aim of our study was to analyze the prognostic value of mast cell, TGF-beta 1 and alpha-SMA expression in IgAN. A survey of the medical records and renal biopsy reports of 62 patients with a diagnosis of IgAN followed-up from 1987 to 2003 was performed. The mean follow-up time was 74.7 +/- 50.0 months. The immunohistochemical studies were performed using a monoclonal antibody anti-human mast cell tryptase, a polyclonal antibody anti-human TGF-beta 1, and a monoclonal antibody anti-human alpha-SMA. An unfavorable clinical course of IgAN was related to interstitial mast cell infiltrates and alpha-SMA expression in the tubulointerstitial area. Expression of glomerular TGF-beta 1 and alpha-SMA, and interstitial TGF-beta 1 is not correlated with clinical course in IgAN. In conclusion, the increased number of mast cells and higher alpha-SMA expression in the tubulointerstitial area may be predictive factors for the poor prognosis of patients with IgAN.
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There is evidence that several fibroblast growth factors (FGFs) are involved in growth and development of the corpus luteum (CL), but many FGFs have not been investigated in this tissue, including FGF10. The objective of this study was to determine if FGF10 and its receptor (FGFR2B) are expressed in the CL. Bovine CL were collected from an abattoir and classed as corpus hemorrhagica (stage 1), developing (stage 11), developed (stage 111), and regressed (stage IV) CL. Expression of FGF10 and FGFR2B mRNA was measured by reverse transcription-polymerase chain reaction (RT-PCR). Both genes were expressed in bovine CL, and FGF10 expression did not differ between stages of CL development. FGF10 protein was localized to large and small luteal cells by immunohistochemistry. FGFR2B expression was approximately threefold higher in regressed compared to developing and developed CL (P < 0.05). To determine if FGF10 and FGFR2B expression is regulated during functional luteolysis, cattle were injected with PGF2 alpha and CL collected at 0, 0.5, 2, 4, 12, 24, 48, and 64 hr thereafter (n = 5 CL/time point), and mRNA abundance was measured by real-time RT-PCR. FGF10 mRNA expression did not change during functional luteolysis, whereas FGFR2B mRNA abundance decreased significantly at 2, 4, and 12 hr after PGF2a, and returned to pretreatment levels for the period 24-64 hr post-PGF2 alpha. These data suggest a potential role for FGFR2B signaling during structural luteolysis in bovine CL.
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Epithelial ovarian carcinoma is often diagnosed at an advanced stage of disease and is the leading cause of death from gynaecological neoplasia. The genetic changes that occur during the development of this carcinoma are poorly understood. It has been proposed that IGFIIR, TGF beta1 and TGF beta RII act as a functional unit in the TGF beta growth inhibitory pathway, and that somatic loss-of-function mutations in any one of these genes could lead to disruption of the pathway and subsequent loss of cell cycle control. We have examined these 3 genes in 25 epithelial ovarian carcinomas using single-stranded conformational polymorphism analysis and DNA sequence analysis. A total of 3 somatic missense mutations were found in the TGF beta RII gene, but none in IGFRII or TGF beta1. An association was found between TGF beta RII mutations and histology, with 2 out of 3 clear cell carcinomas having TGF beta RII mutations. This data supports other evidence from mutational analysis of the PTEN and beta -catenin genes that there are distinct developmental pathways responsible for the progression of different epithelial ovarian cancer histologic subtypes. (C) 2001 Cancer Research Campaign.
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We report on a patient with a severe premature calvarial synostosis and epidermal hyperplasia. The phenotype was consistent with that of a mild presentation of Beare-Stevenson syndrome but molecular analysis of the IgIII-transmembrane linker region and the transmembrane domain of the gene encoding the FGFR2 receptor, revealed wild-type sequence only. Subsequently, molecular analysis of the FGFR3 receptor gene identified a heterozygous P250R missense mutation in both the proposita and her mildly affected father. This communication extends the clinical spectrum of the FGFR3 P250R mutation to encompass epidermal hyperplasia and documents the phenomenon of activated FGFR receptors stimulating common downstream developmental pathways, resulting in overlapping clinical outcomes. (C) 2001 Wiley-Liss, Inc.
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Recent studies have shown that phox homology (PX) domains act as phosphoinositide-binding motifs. The majority of PX domains studied show binding to phosphatidylinositol 3-monophosphate (Ptdlns(3)P), an association that allows the host protein to localize to membranes of the endocytic pathway. One issue, however, is whether PX domains may have alternative phosphoinositide binding specificities that could target their host protein to distinct subcellular compartments or allow their allosteric regulation by phosphoinositides other than PtdIns(3)P. It has been reported that the PX domain of sorting nexin 1 (SNX1) specifically binds phosphatidylinositol 3,4,5-trisphosphate (PtdIns(3,4,5)P-3) (Zhong, Q., Lazar, C. S., Tronchere, H., Sato, T., Meerloo, T., Yeo, M., Songyang, Z., Emr, S. D., and Gill, G. N. (2002) Proc. Natl. Acad. Sci. U. S. A. 99,6767-6772). In the present study, we have shown that whereas SNX1 binds PtdIns(3,4,5)P-3 in protein:lipid overlay assays, in liposomes-based assays, binding is observed to PtdIns(3)P and phosphatidylinositol 3,5-bisphosphate (PtdIns(3,5)P-2) but not to PtdIns(3,4,5)P-3. To address the significance of PtdIns(3,4,5)P-3 binding, we examined the subcellular localization of SNX1 under conditions in which plasma membrane PtdIns(3,4,5)P-3 levels were significantly elevated. Under these conditions, we failed to observe association of SNX1 with this membrane. However, consistent with the binding to PtdIns(3)P and PtdIns(3,5)P-2 being of more physiological significance was the observation that the association of SNX1 with an early endosomal compartment was dependent on a 3-phosphoinositide-binding PX domain and the presence of PtdIns(3)P on this compartment. Finally, we somal association of SNX1 is important for its ability to regulate the targeting of internalized epidermal growth factor receptor for lysosomal degradation.
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Fibroblast growth factor receptor (FGFR) signalling is important in the initiation and regulation of osteogenesis. Although mutations in FGFR1, 2 and 3 genes are known to cause skeletal deformities, the expression of FGFR4 in bony tissue remains unclear. We have investigated the expression pattern of FGFR4 in the neonatal mouse calvaria and compared it to the expression pattern in cultures of primary osteoblasts. Immunohistochemistry demonstrated that FGFR4 was highly expressed in rudimentary membranous bone and strictly localised to the cellular components (osteoblasts) between the periosteal and endosteal layers. Cells in close proximity to the newly formed osteoid (preosteoblasts) also expressed FGFR4 on both the endosteal and periosteal surfaces. Immunocytochemical analysis of primary osteoblast cultures taken from the same cranial region also revealed high levels of FGFR4 expression, suggesting a similar pattern of cellular expression in vivo and in vitro. RT-PCR and Western blotting for FGFR4 confirmed its presence in primary osteoblast cultures. These results suggest that FGFR4 may be an important regulator of osteogenesis with involvement in preosteoblast proliferation and differentiation as well as osteoblast functioning during intramembranous ossification. The consistent expression of FGFR4 in vivo and in vitro supports the use of primary osteoblast cultures for elucidating the role of FGFR4 during osteogenesis.