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1.
J Clin Apher ; 34(4): 490-494, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30673128

RESUMEN

PURPOSE: During a national shortage of calcium gluconate, we switched to calcium chloride for routine supplementation for peripheral blood stem cell (PBSC) collections. Subsequently, we analyzed the postprocedure ionized calcium level, as we aimed for an equivalent result compared to before the shortage. METHODS: Pharmacy representatives helped us to find an "equivalent" substitute for calcium gluconate at 46.5 mEq in 500 mL normal saline, infused at 100 mL/hour. After instituting a presumably comparable protocol using calcium chloride (40.8 mEq in 250 mL normal saline at a rate of 100 mL/hour), we reviewed ionized calcium results post-PBSC procedures to compare with those obtained with calcium gluconate. Having noticed a difference in the mean values, we adjusted the rate of calcium chloride to reach our desired outcome. RESULTS: Twenty-seven procedures were analyzed on 15 unique patients. We used the Spectra OPTIA with a whole blood: anticoagulant ratio of 13:1. Ionized calcium levels post-PBSC collection with the first calcium chloride protocol were significantly higher (P = 0.003) in nine patients treated. Subsequently, we decreased the calcium chloride infusion rate to 75 mL/hour and achieved similar mean levels to calcium gluconate (P = 0.382). CONCLUSION: Changes in replacement fluids for apheresis procedures can be complex, particularly when dealing with electrolytes that could be clinically significant at critically high or low levels. Once we recognized the need to take into account the amount of elemental calcium infused, we achieved the desired postprocedure ionized calcium results. This study can serve as a lesson for future shortages of infusions used during apheresis procedures.


Asunto(s)
Gluconato de Calcio/provisión & distribución , Calcio/administración & dosificación , Citaféresis/métodos , Calcio/farmacocinética , Cloruro de Calcio/administración & dosificación , Humanos , Células Madre de Sangre Periférica/citología
2.
J Neuroophthalmol ; 39(1): 8-13, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29697441

RESUMEN

BACKGROUND: Although giant cell arteritis (GCA) is a well-known cause of transient and permanent vision loss, diplopia as a presenting symptom of this condition is uncommon. We compared symptoms and signs of patients presenting with diplopia from GCA to those from other causes. METHODS: This was a multicenter, retrospective study comparing the clinical characteristics of patients presenting with diplopia from GCA with age-matched controls. Demographic information, review of symptoms, ophthalmic examination, and laboratory data of biopsy-proven patients with GCA were compared with those of age-matched controls presenting with diplopia. RESULTS: A total of 27 patients presented with diplopia from GCA, 19 with constant diplopia, and 8 with transient diplopia. All patients with constant diplopia from GCA were matched with 67 control subjects who had diplopia from other etiologies. Patients with GCA were more likely to describe other accompanying visual symptoms (58% vs 25%, P = 0.008), a greater number of systemic GCA symptoms (3.5, GCA vs 0.6, controls, P < 0.001) such as headache (94% [17/18] vs 39% [23/67]; P < 0.001), jaw claudication (80% [12/15] vs 0% [0/36]; P < 0.001), and scalp tenderness (44% [7/16] vs 7% [3/43]; P < 0.001). Ocular ischemic lesions (26% vs 1%, P < 0.001) were also common in patients with diplopia from GCA. Inflammatory markers were elevated significantly in patients with GCA vs controls (erythrocyte sedimentation rate: 91% [10/11] vs 12% [3/25], P < 0.001; C-reactive protein: 89% [8/9] vs 11% [2/19], P < 0.001). CONCLUSIONS: GCA is a rare but serious cause of diplopia among older adults and must be differentiated from other more common benign etiologies. Our study suggests that most patients with diplopia from GCA have concerning systemic symptoms and/or elevated inflammatory markers that should trigger further work-up. Moreover, careful ophthalmoscopic examination should be performed to look for presence of ocular ischemic lesions in older patients presenting with acute diplopia.


Asunto(s)
Diplopía/etiología , Arteritis de Células Gigantes/complicaciones , Arterias Temporales/patología , Visión Binocular/fisiología , Agudeza Visual/fisiología , Anciano , Biopsia , Sedimentación Sanguínea , Proteína C-Reactiva/metabolismo , Diplopía/diagnóstico , Diplopía/fisiopatología , Femenino , Estudios de Seguimiento , Arteritis de Células Gigantes/diagnóstico , Arteritis de Células Gigantes/metabolismo , Humanos , Masculino , Pronóstico , Estudios Retrospectivos
3.
Retina ; 37(6): 1079-1083, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27749782

RESUMEN

PURPOSE: To determine the effect of cannula removal over the light pipe on the incidence of sclerotomy leakage and to evaluate other factors that may influence the incidence of sclerotomy leaks and hypotony on conclusion of small-gauge transconjunctival pars plana vitrectomy. METHODS: Retrospective, interventional clinical study of consecutive patients who underwent small-gauge transconjunctival pars plana vitrectomy at a single academic center. Eyes were divided into a group in which cannulae were removed over the light pipe (Group L) and a group in which cannulae were simply pulled out (Group N). The primary comparison was the comparison in requirement for suturing of sclerotomies between Groups L and N. RESULTS: Forty-eight eyes of 48 patients were included in the study (Group L: 21 eyes; Group N: 27 eyes). In Group L, 14/42 (33%) superior sclerotomies required suturing compared with 7/54 (13%) sclerotomies in Group N (P = 0.024). Superior sclerotomy leaks were also more common in Group L (28/42, 67%) compared with Group N (23/54, 43%, P = 0.024). Similarly, more eyes had hypotony after cannula removal in Group L (11/21; 52%) compared with Group N (5/27; 19%, P = 0.03). There were no differences in any of these measures when comparing fluid-filled to air- or gas-filled eyes. CONCLUSION: Removing the cannula over the light pipe results in a greater frequency of leaking, including leaking that results in hypotony or that requires suturing. The technique of cannula removal affects the risk of leakage and the risk of requiring suturing of a sclerotomy.


Asunto(s)
Cánula/efectos adversos , Remoción de Dispositivos/efectos adversos , Complicaciones Intraoperatorias/epidemiología , Complicaciones Posoperatorias/epidemiología , Esclerostomía/efectos adversos , Vitrectomía/métodos , Conjuntiva/cirugía , Falla de Equipo , Estudios de Seguimiento , Humanos , Incidencia , Estudios Retrospectivos , Esclerótica/cirugía , Esclerostomía/instrumentación , Estados Unidos/epidemiología
4.
J Neuroophthalmol ; 37(3): 242-246, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28079759

RESUMEN

BACKGROUND: Although QuantiFERON-TB Gold In-Tube (QFT-GIT) testing is regularly used to detect infection with Mycobacterium tuberculosis, its utility in a patient population with a low risk for tuberculosis (TB) has been questioned. The following is a cohort study analyzing the efficacy of QFT-GIT testing as a method for detection of active TB disease in low-risk individuals in a neuro-ophthalmologic setting. METHODS: Ninety-nine patients from 2 neuro-ophthalmology centers were identified as having undergone QFT-GIT testing between January 2012 and February 2016. Patients were divided into groups of negative, indeterminate, and positive QFT-GIT results. Records of patients with positive QFT-GIT results were reviewed for development of latent or active TB, as determined by clinical, bacteriologic, and/or radiographic evidence. RESULTS: Of the 99 cases reviewed, 18 patients had positive QFT-GIT tests. Of these 18 cases, 12 had documentation of chest radiographs or computed tomography which showed no evidence for either active TB or pulmonary latent TB infection (LTBI). Four had chest imaging which was indicative of possible LTBI. None of these 18 patients had symptoms of active TB and none developed active TB within the follow-up period. CONCLUSIONS: Based on our results, we conclude that routine testing with QFT-GIT in a low-risk cohort did not diagnose active TB infection. We do not recommend routine QFT-GIT testing for TB low-risk individuals, as discerned through patient and exposure history, ocular examination, and clinical judgment, in neuro-ophthalmology practice.


Asunto(s)
Antígenos Bacterianos/análisis , Ensayos de Liberación de Interferón gamma/instrumentación , Tuberculosis Latente/diagnóstico , Mycobacterium tuberculosis/inmunología , Neurología/métodos , Oftalmología/métodos , Prueba de Tuberculina/instrumentación , Adulto , Anciano , Diseño de Equipo , Femenino , Humanos , Tuberculosis Latente/microbiología , Masculino , Persona de Mediana Edad , Mycobacterium tuberculosis/aislamiento & purificación , Reproducibilidad de los Resultados , Estudios Retrospectivos
6.
Br J Ophthalmol ; 108(3): 343-348, 2024 02 21.
Artículo en Inglés | MEDLINE | ID: mdl-36746614

RESUMEN

PURPOSE: Corneal biomechanical failure is the hallmark of keratoconus (KC); however, the cause of this failure remains elusive. Collagen type XII (COL12A1), which localises to Bowman's layer (BL), is thought to function in stress-bearing areas, such as BL. Given the putative protective role of COL12A1 in biomechanical stability, this study aims to characterise COL12A1 expression in all corneal layers involved in KC. METHODS: TaqMan quantitative PCR was performed on 31 corneal epithelium samples of progressive KC and myopic control eyes. Tissue microarrays were constructed using full-thickness corneas from 61 KC cases during keratoplasty and 18 non-KC autopsy eyes and stained with an antibody specific to COL12A1. Additionally, COL12A1 was knocked out in vitro in immortalised HEK293 cells. RESULTS: COL12A1 expression was reduced at transcript levels in KC epithelium compared with controls (ratio: 0.58, p<0.03). Immunohistochemical studies demonstrated that COL12A1 protein expression in BL was undetectable, with reduced expression in KC epithelium, basement membrane and stroma. CONCLUSIONS: The apparent absence of COL12A1 in KC BL, together with the functional importance that COL12A1 is thought to have in stress bearing areas, suggests that COL12A1 may play a role in the pathogenesis of KC. Further studies are necessary to investigate the mechanisms that lead to COL12A1 dysregulation in KC.


Asunto(s)
Epitelio Corneal , Queratocono , Humanos , Queratocono/metabolismo , Colágeno Tipo XII/genética , Colágeno Tipo XII/metabolismo , Células HEK293 , Córnea/patología , Epitelio Corneal/patología
7.
Cornea ; 42(1): 105-109, 2023 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-35965394

RESUMEN

PURPOSE: The aim of the current research was to measure the thickness of the residual central corneal bed after performing the manual "Groove and Peel" deep anterior lamellar keratoplasty (GP-DALK) technique on human cadaveric eyes. METHODS: The manual GP-DALK technique was performed on 6 human cadaver eyes by an experienced corneal surgeon. After surgery, the eye globes were fixed in 10% buffered formalin and embedded in paraffin. For each eye, 4-µm-thick hematoxylin and eosin sections involving the pupillary axis were obtained and examined. Using an image-processing software, 2 observers measured the corneal thickness of the residual central corneal bed and the peripheral corneal rims. RESULTS: The overall mean central corneal bed thickness was 35.5 ± 12.9 µm, whereas the mean right and left peripheral rim thicknesses were 993.0 ± 141.1 and 989.3 ± 147.1 µm, respectively ( P = 0.0006 ). In most corneas, the level of dissection reached almost to the pre-Descemetic collagen (Dua) layer. CONCLUSIONS: The GP-DALK technique is effective in removing most of the corneal stroma and may be non-inferior to "big-bubble" deep anterior lamellar keratoplasty in some cases.


Asunto(s)
Sustancia Propia , Trasplante de Córnea , Humanos , Sustancia Propia/cirugía , Cadáver , Córnea , Membrana Celular , Progresión de la Enfermedad
8.
Cancers (Basel) ; 14(13)2022 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-35804893

RESUMEN

Alterations in metabolism and energy production are increasingly being recognized as important drivers of neoplasia, raising the possibility that metabolic analogs could disrupt oncogenic pathways. 3'-deoxyadenosine, also known as cordycepin, is an adenosine analog that inhibits the growth of several types of cancer. However, the effects of cordycepin have only been examined in a limited number of tumor types, and its mechanism of action is poorly understood. We found that cordycepin slows the growth and promotes apoptosis in uveal melanoma, as well as a range of other hard-to-treat malignancies, including retinoblastoma, atypical teratoid rhabdoid tumors, and diffuse midline gliomas. Interestingly, these effects were dependent on low adenosine deaminase (ADA) expression or activity. Inhibition of ADA using either siRNA or pharmacologic approaches sensitized tumors with higher ADA to cordycepin in vitro and in vivo, with increased apoptosis, reduced clonogenic capacity, and slower migration of neoplastic cells. Our studies suggest that ADA is both a biomarker predicting response to cordycepin and a target for combination therapy. We also describe a novel mechanism of action for cordycepin: competition with adenosine triphosphate (ATP) in binding to Hsp90, resulting in impaired processing of oncogenic Hsp90 client proteins.

9.
Oncogene ; 40(45): 6329-6342, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34433909

RESUMEN

Hepatocyte growth factor-overexpressing mice that harbor a deletion of the Ink4a/p16 locus (HP mice) form melanomas with low metastatic potential in response to UV irradiation. Here we report that these tumors become highly metastatic following hemizygous deletion of the Nme1 and Nme2 metastasis suppressor genes (HPN mice). Whole-genome sequencing of melanomas from HPN mice revealed a striking increase in lung metastatic activity that is associated with missense mutations in eight signature genes (Arhgap35, Atp8b4, Brca1, Ift172, Kif21b, Nckap5, Pcdha2, and Zfp869). RNA-seq analysis of transcriptomes from HP and HPN primary melanomas identified a 32-gene signature (HPN lung metastasis signature) for which decreased expression is strongly associated with lung metastatic potential. Analysis of transcriptome data from The Cancer Genome Atlas revealed expression profiles of these genes that predict improved survival of patients with cutaneous or uveal melanoma. Silencing of three representative HPN lung metastasis signature genes (ARRDC3, NYNRIN, RND3) in human melanoma cells resulted in increased invasive activity, consistent with roles for these genes as mediators of the metastasis suppressor function of NME1 and NME2. In conclusion, our studies have identified a family of genes that mediate suppression of melanoma lung metastasis, and which may serve as prognostic markers and/or therapeutic targets for clinical management of metastatic melanoma.


Asunto(s)
Biomarcadores de Tumor/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/secundario , Melanoma/genética , Nucleósido Difosfato Quinasas NM23/genética , Rayos Ultravioleta/efectos adversos , Animales , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Factor de Crecimiento de Hepatocito/genética , Humanos , Melanoma/etiología , Ratones , Mutación Missense , Análisis de Secuencia de ARN , Análisis de Supervivencia , Secuenciación Completa del Genoma
10.
Surv Ophthalmol ; 62(2): 150-160, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-27751821

RESUMEN

Cryptococcal meningitis is the most common and severe form of cryptococcal infection. In addition to infiltrative and inflammatory mechanisms, intracranial hypertension commonly complicates cryptococcal meningitis and may cause significant visual and neurological morbidity and mortality. The mainstays of treatment for cryptococcal meningitis include standard antifungal therapy, management of intracranial hypertension, and treatment of underlying immunosuppressive conditions. Early and aggressive management of intracranial hypertension in accordance with established guidelines reduces the risk of long-term visual and neurological complications and death. Traditional recommendations for treating elevated intracranial pressure in idiopathic intracranial hypertension including acetazolamide, weight loss, and avoiding serial lumbar punctures-are not helpful in cryptococcal meningitis and may be harmful.


Asunto(s)
Antifúngicos/uso terapéutico , Manejo de la Enfermedad , Meningitis Criptocócica/complicaciones , Disco Óptico/diagnóstico por imagen , Papiledema/etiología , Punción Espinal/métodos , Humanos , Meningitis Criptocócica/tratamiento farmacológico , Papiledema/diagnóstico , Papiledema/terapia
11.
PLoS One ; 11(1): e0147760, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26815917

RESUMEN

PURPOSE: Define criteria for iris-related parameters in an adult open angle population as measured with swept source Fourier domain anterior segment optical coherence tomography (ASOCT). METHODS: Ninety-eight eyes of 98 participants with open angles were included and stratified into 5 age groups (18-35, 36-45, 46-55, 56-65, and 66-79 years). ASOCT scans with 3D mode angle analysis were taken with the CASIA SS-1000 (Tomey Corporation, Nagoya, Japan) and analyzed using the Anterior Chamber Analysis and Interpretation software. Anterior iris surface length (AISL), length of scleral spur landmark (SSL) to pupillary margin (SSL-to-PM), iris contour ratio (ICR = AISL/SSL-to-PM), pupil radius, radius of iris centroid (RICe), and iris volume were measured. Outcome variables were summarized for all eyes and age groups, and mean values among age groups were compared using one-way analysis of variance. Stepwise regression analysis was used to investigate demographic and ocular characteristic factors that affected each iris-related parameter. RESULTS: Mean (±SD) values were 2.24 mm (±0.46), 4.06 mm (±0.27), 3.65 mm (±0.48), 4.16 mm (±0.47), 1.14 (±0.04), 1.51 mm2 (±0.23), and 38.42 µL (±4.91) for pupillary radius, RICe, SSL-to-PM, AISL, ICR, iris cross-sectional area, and iris volume, respectively. Both pupillary radius (P = 0.002) and RICe (P = 0.027) decreased with age, while SSL-to-PM (P = 0.002) and AISL increased with age (P = 0.001). ICR (P = 0.54) and iris volume (P = 0.49) were not affected by age. CONCLUSION: This study establishes reference values for iris-related parameters in an adult open angle population, which will be useful for future studies examining the role of iris changes in pathologic states.


Asunto(s)
Glaucoma de Ángulo Abierto/patología , Iris/patología , Hipertensión Ocular/patología , Tomografía de Coherencia Óptica/métodos , Adolescente , Adulto , Factores de Edad , Anciano , Segmento Anterior del Ojo/patología , Femenino , Glaucoma de Ángulo Abierto/diagnóstico , Humanos , Masculino , Persona de Mediana Edad , Hipertensión Ocular/diagnóstico , Valores de Referencia , Adulto Joven
12.
J Ophthalmol ; 2016: 1727039, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27990300

RESUMEN

Purpose. To evaluate interobserver, intervisit, and interinstrument agreements for gonioscopy and Fourier domain anterior segment optical coherence tomography (FD ASOCT) for classifying open and narrow angle eyes. Methods. Eighty-six eyes with open or narrow anterior chamber angles were included. The superior angle was classified open or narrow by 2 of 5 glaucoma specialists using gonioscopy and imaged by FD ASOCT in the dark. The superior angle of each FD ASOCT image was graded as open or narrow by 2 masked readers. The same procedures were repeated within 6 months. Kappas for interobserver and intervisit agreements for each instrument and interinstrument agreements were calculated. Results. The mean age was 50.9 (±18.4) years. Interobserver agreements were moderate to good for both gonioscopy (0.57 and 0.69) and FD ASOCT (0.58 and 0.75). Intervisit agreements were moderate to excellent for both gonioscopy (0.53 to 0.86) and FD ASOCT (0.57 and 0.85). Interinstrument agreements were fair to good (0.34 to 0.63), with FD ASOCT classifying more angles as narrow than gonioscopy. Conclusions. Both gonioscopy and FD ASOCT examiners were internally consistent with similar interobserver and intervisit agreements for angle classification. Agreement between instruments was fair to good, with FD ASOCT classifying more angles as narrow than gonioscopy.

14.
Eye Brain ; 7: 47-57, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-28539794

RESUMEN

Papilledema is optic disc swelling due to high intracranial pressure. Possible conditions causing high intracranial pressure and papilledema include intracerebral mass lesions, cerebral hemorrhage, head trauma, meningitis, hydrocephalus, spinal cord lesions, impairment of cerebral sinus drainage, anomalies of the cranium, and idiopathic intracranial hypertension (IIH). Irrespective of the cause, visual loss is the feared morbidity of papilledema, and the main mechanism of optic nerve damage is intraneuronal ischemia secondary to axoplasmic flow stasis. Treatment is directed at correcting the underlying cause. In cases where there is no other identifiable cause for intracranial hypertension (ie, IIH) the available options include both medical and surgical modalities. Weight loss and diuretics remain the mainstays for treatment of IIH, and surgery is typically reserved for patients who fail, are intolerant to, or non-compliant with maximum medical therapy.

15.
J Ophthalmol ; 2014: 590978, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25210623

RESUMEN

Purpose. To introduce a new anterior segment optical coherence tomography parameter, trabecular-iris circumference volume (TICV), which measures the integrated volume of the peripheral angle, and establish a reference range in normal, open angle eyes. Methods. One eye of each participant with open angles and a normal anterior segment was imaged using 3D mode by the CASIA SS-1000 (Tomey, Nagoya, Japan). Trabecular-iris space area (TISA) and TICV at 500 and 750 µm were calculated. Analysis of covariance was performed to examine the effect of age and its interaction with spherical equivalent. Results. The study included 100 participants with a mean age of 50 (±15) years (range 20-79). TICV showed a normal distribution with a mean (±SD) value of 4.75 µL (±2.30) for TICV500 and a mean (±SD) value of 8.90 µL (±3.88) for TICV750. Overall, TICV showed an age-related reduction (P = 0.035). In addition, angle volume increased with increased myopia for all age groups, except for those older than 65 years. Conclusions. This study introduces a new parameter to measure peripheral angle volume, TICV, with age-adjusted normal ranges for open angle eyes. Further investigation is warranted to determine the clinical utility of this new parameter.

17.
Neoplasia ; 12(11): 856-65, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21076612

RESUMEN

GATA6 is a zinc finger transcription factor expressed in the colorectal epithelium. We have examined the expression of GATA6 in colon cancers and investigated the mechanisms by which GATA6 regulates colon cancer cell invasion. GATA6 was overexpressed in colorectal polyps and primary and metastatic tumors. GATA6 was strongly expressed in both the nuclear and cytoplasmic compartments of the colon cancer cells. GATA6 expression was upregulated in invasive HT29 and KM12L4 cells compared with the parental HT29 and KM12 cells and positively correlated with urokinase-type plasminogen activator (uPA) gene expression. Small interfering RNA (siRNA) knockdown of GATA6 resulted in reduced uPA gene expression and cell invasion. GATA6 bound to the uPA gene regulatory sequences in vivo and activated uPA promoter activity in vitro. uPA promoter deletion analysis indicated that the promoter proximal Sp1 sites were required for GATA6 activation of the uPA promoter. Accordingly, GATA6 physically associated with Sp1 and siRNA knockdown of Sp1 decreased GATA6 activation of the uPA promoter activity suggesting that Sp1 recruits GATA6 to the uPA promoter and mediates GATA6 induced activation of the uPA promoter activity. On the basis of our results, we conclude that GATA6 is an important regulator of uPA gene expression, and the dysregulated expression of GATA6 contributes to colorectal tumorigenesis and tumor invasion.


Asunto(s)
Factor de Transcripción GATA6/metabolismo , Secuencias Reguladoras de Ácidos Nucleicos/genética , Activador de Plasminógeno de Tipo Uroquinasa/metabolismo , Sitios de Unión/genética , Western Blotting , Línea Celular Tumoral , Movimiento Celular , Inmunoprecipitación de Cromatina , Neoplasias del Colon/genética , Neoplasias del Colon/metabolismo , Neoplasias del Colon/patología , Factor de Transcripción GATA6/genética , Regulación Neoplásica de la Expresión Génica , Células HCT116 , Células HT29 , Humanos , Inmunohistoquímica , Luciferasas/genética , Luciferasas/metabolismo , Invasividad Neoplásica , Metástasis de la Neoplasia , Regiones Promotoras Genéticas/genética , Unión Proteica , Interferencia de ARN , Factor de Transcripción Sp1/genética , Factor de Transcripción Sp1/metabolismo , Activador de Plasminógeno de Tipo Uroquinasa/genética
18.
Am J Physiol Gastrointest Liver Physiol ; 292(6): G1520-33, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17290010

RESUMEN

Members of the transforming growth factor-beta (TGF-beta) family have been shown to play an important role in the regulation of gut epithelial gene expression. We have used the intestinal alkaline phosphatase (IAP) and intestinal fatty acid binding protein (IFABP) promoters to dissect the mechanisms by which TGF-beta1 signaling regulates gut epithelial gene expression. TGF-beta signaling alone was not sufficient for activation of IAP and IFABP promoters. However, TGF-beta signaling cooperated with the gut epithelial transcription factor GATA4 to synergistically activate IAP and IFABP promoters. Coexpression of GATA4 along with the TGF-beta1 signal transducing downstream effectors such as Smad2, 3, and 4 resulted in synergistic activation of both IAP and IFABP promoters. This synergistic activation was reduced by simultaneous expression of dominant-negative Smad4. -40 and -89 GATA binding sites in the IFABP promoter were required for the synergistic activation by Smad2, 3, and 4 and GATA4. GATA4 and Smad2, 3, and 4 physically associated with each other and this interaction was mediated through the MH2 domain of Smad2, 3, and 4 and the second zinc finger and the COOH-terminal basic domain of GATA4. The COOH-terminal activation domain and the Smad-interacting second zinc finger domain of GATA4 were required for the synergistic activation of the IFABP promoter. Naturally occurring oncogenic mutations within the GATA4-interacting MH2 domain of Smad2 reduced the coactivation of IFABP promoter by Smad2 and GATA4. Our results suggest that the TGF-beta signaling regulates gut epithelial gene expression by targeting GATA4.


Asunto(s)
Células Epiteliales/metabolismo , Proteínas de Unión a Ácidos Grasos/metabolismo , Factor de Transcripción GATA4/metabolismo , Expresión Génica , Mucosa Intestinal/metabolismo , Regiones Promotoras Genéticas , Transducción de Señal , Factor de Crecimiento Transformador beta1/metabolismo , Receptores de Activinas Tipo I/metabolismo , Fosfatasa Alcalina , Animales , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/metabolismo , Células Epiteliales/patología , Proteínas de Unión a Ácidos Grasos/genética , Factor de Transcripción GATA4/química , Factor de Transcripción GATA4/genética , Proteínas Ligadas a GPI , Genes Reporteros , Células HCT116 , Haplorrinos , Humanos , Mucosa Intestinal/patología , Luciferasas , Mutación , Unión Proteica , Proteínas Serina-Treonina Quinasas , Estructura Terciaria de Proteína , Interferencia de ARN , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/metabolismo , Receptor Tipo I de Factor de Crecimiento Transformador beta , Receptores de Factores de Crecimiento Transformadores beta/metabolismo , Transducción de Señal/genética , Proteína Smad2/metabolismo , Proteína smad3/metabolismo , Proteína Smad4/metabolismo , Transfección , Factor de Crecimiento Transformador beta1/genética , Dedos de Zinc
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