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1.
Nutrients ; 16(1)2024 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-38201998

RESUMEN

The receptor protein tyrosine phosphatase phogrin primarily localizes to hormone secretory granules in neuroendocrine cells. Concurrent with glucose-stimulated insulin secretion, phogrin translocates to pancreatic ß-cell plasma membranes, where it interacts with insulin receptors (IRs) to stabilize insulin receptor substrate 2 (IRS2) that, in turn, contributes to glucose-responsive ß-cell growth. Pancreatic ß-cell development was not altered in ß-cell-specific, phogrin-deficient mice, but the thymidine incorporation rate decreased in phogrin-deficient islets with a moderate reduction in IRS2 protein expression. In this study, we analyzed the ß-cell response to high-fat diet stress and found that the compensatory expansion in ß-cell mass was significantly suppressed in phogrin-deficient mice. Phogrin-IR interactions occurred only in high-fat diet murine islets and proliferating ß-cell lines, whereas they were inhibited by the intercellular binding of surface phogrin under confluent cell culture conditions. Thus, phogrin could regulate glucose-stimulated compensatory ß-cell growth by changing its binding partner from another ß-cell phogrin to IR in the same ß-cells.


Asunto(s)
Técnicas de Cultivo de Célula , Dieta Alta en Grasa , Animales , Ratones , Dieta Alta en Grasa/efectos adversos , Proliferación Celular , Ciclo Celular , Glucosa
2.
Histochem Cell Biol ; 161(3): 223-238, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38150052

RESUMEN

We recently reported that phogrin, also known as IA-2ß or PTPRN2, forms a complex with the insulin receptor in pancreatic ß cells upon glucose stimulation and stabilizes insulin receptor substrate 2. In ß cells of systemic phogrin gene knockout (IA-2ß-/-) mice, impaired glucose-induced insulin secretion, decreased insulin granule density, and an increase in the number and size of lysosomes have been reported. Since phogrin is expressed not only in ß cells but also in various neuroendocrine cells, the precise impact of phogrin expressed in ß cells on these cells remains unclear. In this study, we performed a comprehensive analysis of morphological changes in RIP-Cre+/-Phogrinflox/flox (ßKO) mice with ß cell-specific phogrin gene knockout. Compared to control RIP-Cre+/- Phogrin+/+ (Ctrl) mice, aged ßKO mice exhibited a decreased density of insulin granules, which can be categorized into three subtypes. While no differences were observed in the density and size of lysosomes and crinosomes, organelles involved in insulin granule reduction, significant alterations in the regions of lysosomes responding positively to carbohydrate labeling were evident in young ßKO mice. These alterations differed from those in Ctrl mice and continued to change with age. These electron microscopic findings suggest that phogrin expression in pancreatic ß cells plays a role in insulin granule homeostasis and crinophagy during aging, potentially through insulin autocrine signaling and other mechanisms.


Asunto(s)
Células Secretoras de Insulina , Insulina , Animales , Ratones , Glucosa/metabolismo , Insulina/metabolismo , Secreción de Insulina , Células Secretoras de Insulina/metabolismo , Proteínas de la Membrana/metabolismo , Ratones Noqueados
3.
J Histochem Cytochem ; 70(5): 335-356, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35400231

RESUMEN

Secretogranin II (SgII) and III (SgIII) function within peptide hormone-producing cells and are involved in secretory granule formation. However, their function in active amine-producing cells is not fully understood. In this study, we analyzed the expression profiles of SgII and SgIII in canine adrenal medulla and pheochromocytomas by immunohistochemical staining. In normal adrenal tissues, the intensity of coexpression of these two secretogranins (Sgs) differed from each chromaffin cell, although a complete match was not observed. The coexpression of vesicular monoamine transporter 2 (VMAT2) with SgIII was similar to that with chromogranin A, but there was a subpopulation of VMAT2-expressing cells that were negative or hardly detectable for SgII. These results are the first to indicate that there are distinct expression patterns for SgII and SgIII in adrenal chromaffin cells. Furthermore, the expression of these two Sgs varied in intensity among pheochromocytomas and did not necessarily correlate with clinical plasma catecholamine levels in patients. However, compared with SgIII, the expression of SgII was shown to be strong at the single-cell level in some tumor tissues. These findings provide a fundamental understanding of the expression differences between SgII and SgIII in normal adrenal chromaffin cells and pheochromocytomas.


Asunto(s)
Neoplasias de las Glándulas Suprarrenales , Células Cromafines , Feocromocitoma , Neoplasias de las Glándulas Suprarrenales/metabolismo , Neoplasias de las Glándulas Suprarrenales/patología , Neoplasias de las Glándulas Suprarrenales/veterinaria , Animales , Células Cromafines/metabolismo , Células Cromafines/patología , Cromograninas/metabolismo , Perros , Humanos , Feocromocitoma/metabolismo , Feocromocitoma/patología , Feocromocitoma/veterinaria , Secretogranina II/metabolismo
4.
J Histochem Cytochem ; 69(4): 229-243, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33622062

RESUMEN

Secretogranin III (SgIII) is a granin protein involved in secretory granule formation in peptide-hormone-producing endocrine cells. In this study, we analyzed the expression of the LacZ reporter in the SgIII knockout mice produced by gene trapping (SgIII-gtKO) for the purpose of comprehensively clarifying the expression patterns of SgIII at the cell and tissue levels. In the endocrine tissues of SgIII-gtKO mice, LacZ expression was observed in the pituitary gland, adrenal medulla, and pancreatic islets, where SgIII expression has been canonically revealed. LacZ expression was extensively observed in brain regions, especially in the cerebral cortex, hippocampus, hypothalamic nuclei, cerebellum, and spinal cord. In peripheral nervous tissues, LacZ expression was observed in the retina, optic nerve, and trigeminal ganglion. LacZ expression was particularly prominent in astrocytes, in addition to neurons and ependymal cells. In the cerebellum, at least four cell types expressed SgIII under basal conditions. The expression of SgIII in the glioma cell lines C6 and RGC-6 was enhanced by excitatory glutamate treatment. It also became clear that the expression level of SgIII varied among neuron and astrocyte subtypes. These results suggest that SgIII is involved in glial cell function, in addition to neuroendocrine functions, in the nervous system.


Asunto(s)
Cromograninas/genética , Operón Lac/genética , Animales , Células Cultivadas , Cromograninas/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratas
5.
Sci Rep ; 10(1): 7454, 2020 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-32350339

RESUMEN

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

6.
Sci Rep ; 10(1): 4802, 2020 03 16.
Artículo en Inglés | MEDLINE | ID: mdl-32179849

RESUMEN

The future time of emergence when precipitation changes due to anthropogenic influences begins to continuously exceed the previous maximum value is defined as the 'tipping year' Historical experiments and future experiments simulated by state-of-the-art climate models were utilized. A total of 510,000 time series from year 1856 to 2095 were generated by sampling the natural internal variability in precipitation. The time evolutions of internal variability in the whole time period were estimated from the combination of past and future experiments with preindustrial control experiments. A large ensemble size enabled an estimation of the probability density function of the tipping year at each grid point, providing precise information on the uncertainty of the projection. The tipping year of average precipitation emerges earlier in high latitudes than in lower latitudes. In some regions in lower latitudes and mid-latitudes, the tipping year of intense precipitation emerges faster than that of average precipitation. The tipping years of average and intense precipitation are earlier for higher anthropogenic forcing scenarios than for lower scenarios. The global average of the tipping year for intense precipitation might be attributed to the enhancement of the thermodynamic effect (moisture) rather than the dynamic effect (vertical motion).

7.
Biochem J ; 476(5): 827-842, 2019 03 12.
Artículo en Inglés | MEDLINE | ID: mdl-30787050

RESUMEN

To closely mimic physiological conditions, low oxygen cultures have been employed in stem cell and cancer research. Although in vivo oxygen concentrations in tissues are often much lower than ambient 21% O2 (ranging from 3.6 to 12.8% O2), most cell cultures are maintained at 21% O2 To clarify the effects of the O2 culture concentration on the regulated secretion of peptide hormones in neuro-endocrine cells, we examined the changes in the storage and release of peptide hormones in neuro-endocrine cell lines and endocrine tissues cultured in a relatively lower O2 concentration. In both AtT-20 cells derived from the mouse anterior pituitary and freshly prepared mouse pituitaries cultured in 10% O2 for 24 h, the storage and regulated secretion of the mature peptide hormone adrenocorticotropic hormone were significantly increased compared with those in cells and pituitaries cultured in ambient 21% O2, whereas its precursor proopiomelanocortin was not increased in the cells and tissues after being cultured in 10% O2 Simultaneously, the prohormone-processing enzymes PC1/3 and carboxypeptidase E were up-regulated in cells cultured in 10% O2, thus facilitating the conversion of prohormones to their active form. Similarly, culturing the mouse ß-cell line MIN6 and islet tissue in 10% O2 also significantly increased the conversion of proinsulin into mature insulin, which was secreted in a regulated manner. These results suggest that culture under 10% O2 is more optimal for endocrine tissues/cells to efficiently generate and secrete active peptide hormones than ambient 21% O2.


Asunto(s)
Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Células Neuroendocrinas/metabolismo , Oxígeno/farmacología , Adenohipófisis/metabolismo , Proopiomelanocortina/biosíntesis , Regulación hacia Arriba/efectos de los fármacos , Animales , Técnicas de Cultivo de Célula , Línea Celular , Ratones
8.
J Biol Chem ; 293(16): 5920-5933, 2018 04 20.
Artículo en Inglés | MEDLINE | ID: mdl-29483197

RESUMEN

Autocrine insulin signaling is critical for pancreatic ß-cell growth and activity and is at least partially controlled by protein-tyrosine phosphatases (PTPs) that act on insulin receptors (IRs). The receptor-type PTP phogrin primarily localizes on insulin secretory granules in pancreatic ß cells. We recently reported that phogrin knockdown decreases the protein levels of insulin receptor substrate 2 (IRS2), whereas high-glucose stimulation promotes formation of a phogrin-IR complex that stabilizes IRS2. However, the underlying molecular mechanisms by which phogrin affects IRS2 levels are unclear. Here, we found that relative to wildtype mice, IRS2 levels in phogrin-knockout mice islets decreased by 44%. When phogrin was silenced by shRNA in pancreatic ß-cell lines, glucose-induced insulin signaling led to proteasomal degradation of IRS2 via a negative feedback mechanism. Phogrin overexpression in a murine hepatocyte cell line consistently prevented chronic insulin treatment-induced IRS2 degradation. In vitro, phogrin directly bound the IR without the assistance of other proteins and protected recombinant PTP1B from oxidation to potentiate its activity toward the IR. Furthermore, phogrin expression suppressed insulin-induced local generation of hydrogen peroxide and subsequent PTP1B oxidation, which allowed progression of IR dephosphorylation. Together, these results suggest that a transient interaction of phogrin with the IR enables glucose-stimulated autocrine insulin signaling through the regulation of PTP1B activity, which is essential for suppressing feedback-mediated IRS2 degradation in pancreatic ß cells.


Asunto(s)
Glucosa/metabolismo , Proteínas Sustrato del Receptor de Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas Tirosina Fosfatasas Clase 8 Similares a Receptores/metabolismo , Transducción de Señal , Animales , Línea Celular , Femenino , Silenciador del Gen , Masculino , Proteínas de la Membrana/genética , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Proteolisis , Proteínas Tirosina Fosfatasas Clase 8 Similares a Receptores/genética
9.
Endocrinology ; 159(2): 1213-1227, 2018 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-29281094

RESUMEN

Secretogranin III (SgIII), a member of the granin family, binds both to another granin, chromogranin A (CgA), and to a cholesterol-rich membrane that is destined for secretory granules (SGs). The knockdown of SgIII in adrenocorticotropic hormone (ACTH)-producing AtT-20 cells largely impairs the regulated secretion of CgA and ACTH. To clarify the physiological roles of SgIII in vivo, we analyzed hormone secretion and SG biogenesis in newly established SgIII-knockout (KO) mice. Although the SgIII-KO mice were viable and fertile and exhibited no overt abnormalities under ordinary rearing conditions, a high-fat/high-sucrose diet caused pronounced obesity in the mice. Furthermore, in the SgIII-KO mice compared with wild-type (WT) mice, the stimulated secretion of active insulin decreased substantially, whereas the storage of proinsulin increased in the islets. The plasma ACTH was also less elevated in the SgIII-KO mice than in the WT mice after chronic restraint stress, whereas the storage level of the precursor proopiomelanocortin in the pituitary gland was somewhat increased. These findings suggest that the lack of SgIII causes maladaptation of endocrine cells to an inadequate diet and stress by impairing the proteolytic conversion of prohormones in SGs, whereas SG biogenesis and the basal secretion of peptide hormones under ordinary conditions are ensured by the compensatory upregulation of other residual granins or factors.


Asunto(s)
Adaptación Fisiológica/genética , Cromograninas/genética , Cromograninas/metabolismo , Dieta/efectos adversos , Precursores de Proteínas/genética , Precursores de Proteínas/metabolismo , Estrés Fisiológico/fisiología , Animales , Células Cultivadas , Masculino , Enfermedades Metabólicas/genética , Enfermedades Metabólicas/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Procesamiento Proteico-Postraduccional , Estrés Fisiológico/genética
10.
J Histochem Cytochem ; 65(11): 637-653, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28914590

RESUMEN

The comparative structure and expression of salivary components and vesicular transport proteins in the canine major salivary glands were investigated. Histochemical analysis revealed that the morphology of the five major salivary glands-parotid, submandibular, polystomatic sublingual, monostomatic sublingual, and zygomatic glands-was greatly diverse. Immunoblot analysis revealed that expression levels of α-amylase and antimicrobial proteins, such as lysozyme, lactoperoxidase, and lactoferrin, differed among the different glands. Similarly, Rab proteins (Rab3d, Rab11a, Rab11b, Rab27a, and Rab27b) and soluble N-ethylmaleimide-sensitive fusion protein attachment protein receptor (SNARE) proteins VAMP4, VAMP8, syntaxin-2, syntaxin-3, syntaxin-4, and syntaxin-6 were expressed at various levels in individual glands. mmunohistochemistry of Rab3d, Rab11b, Rab27b, VAMP4, VAMP8, syntaxin-4, and syntaxin-6 revealed their predominant expression in serous acinar cells, demilunes, and ductal cells. The VAMP4/syntaxin-6 SNARE complex, which is thought to be involved in the maturation of secretory granules in the Golgi field, was found more predominantly in the monostomatic sublingual gland than in the parotid gland. These results suggest that protein expression profiles in canine salivary glands differ among individual glands and reflect the properties of their specialized functions.


Asunto(s)
Proteínas de Unión al ARN/metabolismo , Proteínas SNARE/metabolismo , Glándulas Salivales/metabolismo , Animales , Western Blotting , Perros , Inmunohistoquímica , Inmunoprecipitación , Masculino , Unión Proteica , Proteínas y Péptidos Salivales/metabolismo
11.
Med Phys ; 43(3): 1437-50, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26936728

RESUMEN

PURPOSE: The main purpose in this study was to present the results of beam modeling and how the authors systematically investigated the influence of double and triple Gaussian proton kernel models on the accuracy of dose calculations for spot scanning technique. METHODS: The accuracy of calculations was important for treatment planning software (TPS) because the energy, spot position, and absolute dose had to be determined by TPS for the spot scanning technique. The dose distribution was calculated by convolving in-air fluence with the dose kernel. The dose kernel was the in-water 3D dose distribution of an infinitesimal pencil beam and consisted of an integral depth dose (IDD) and a lateral distribution. Accurate modeling of the low-dose region was important for spot scanning technique because the dose distribution was formed by cumulating hundreds or thousands of delivered beams. The authors employed a double Gaussian function as the in-air fluence model of an individual beam. Double and triple Gaussian kernel models were also prepared for comparison. The parameters of the kernel lateral model were derived by fitting a simulated in-water lateral dose profile induced by an infinitesimal proton beam, whose emittance was zero, at various depths using Monte Carlo (MC) simulation. The fitted parameters were interpolated as a function of depth in water and stored as a separate look-up table. These stored parameters for each energy and depth in water were acquired from the look-up table when incorporating them into the TPS. The modeling process for the in-air fluence and IDD was based on the method proposed in the literature. These were derived using MC simulation and measured data. The authors compared the measured and calculated absolute doses at the center of the spread-out Bragg peak (SOBP) under various volumetric irradiation conditions to systematically investigate the influence of the two types of kernel models on the dose calculations. RESULTS: The authors investigated the difference between double and triple Gaussian kernel models. The authors found that the difference between the two studied kernel models appeared at mid-depths and the accuracy of predicting the double Gaussian model deteriorated at the low-dose bump that appeared at mid-depths. When the authors employed the double Gaussian kernel model, the accuracy of calculations for the absolute dose at the center of the SOBP varied with irradiation conditions and the maximum difference was 3.4%. In contrast, the results obtained from calculations with the triple Gaussian kernel model indicated good agreement with the measurements within ±1.1%, regardless of the irradiation conditions. CONCLUSIONS: The difference between the results obtained with the two types of studied kernel models was distinct in the high energy region. The accuracy of calculations with the double Gaussian kernel model varied with the field size and SOBP width because the accuracy of prediction with the double Gaussian model was insufficient at the low-dose bump. The evaluation was only qualitative under limited volumetric irradiation conditions. Further accumulation of measured data would be needed to quantitatively comprehend what influence the double and triple Gaussian kernel models had on the accuracy of dose calculations.


Asunto(s)
Método de Montecarlo , Terapia de Protones , Dosis de Radiación , Planificación de la Radioterapia Asistida por Computador/métodos , Algoritmos , Distribución Normal , Dosificación Radioterapéutica , Programas Informáticos
12.
Clim Dyn ; 47(11): 3517-3545, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32742080

RESUMEN

The second West African Monsoon Modeling and Evaluation Project Experiment (WAMME II) is designed to improve understanding of the possible roles and feedbacks of sea surface temperature (SST), land use land cover change (LULCC), and aerosols forcings in the Sahel climate system at seasonal to decadal scales. The project's strategy is to apply prescribed observationally based anomaly forcing, i.e., "idealized but realistic" forcing, in simulations by climate models. The goal is to assess these forcings' effects in producing/amplifying seasonal and decadal climate variability in the Sahel between the 1950s and the 1980s, which is selected to characterize the great drought period of the last century. This is the first multi-model experiment specifically designed to simultaneously evaluate such relative contributions. The WAMME II models have consistently demonstrated that SST forcing is a major contributor to the 20th century Sahel drought. Under the influence of the maximum possible SST forcing, the ensemble mean of WAMME II models can produce up to 60% of the precipitation difference during the period. The present paper also addresses the role of SSTs in triggering and maintaining the Sahel drought. In this regard, the consensus of WAMME II models is that both Indian and Pacific Ocean SSTs greatly contributed to the drought, with the former producing an anomalous displacement of the Intertropical Convergence Zone (ITCZ) before the WAM onset, and the latter mainly contributes to the summer WAM drought. The WAMME II models also show that the impact of LULCC forcing on the Sahel climate system is weaker than that of SST forcing, but still of first order magnitude. According to the results, under LULCC forcing the ensemble mean of WAMME II models can produces about 40% of the precipitation difference between the 1980s and the 1950s. The role of land surface processes in responding to and amplifying the drought is also identified. The results suggest that catastrophic consequences are likely to occur in the regional Sahel climate when SST anomalies in individual ocean basins and in land conditions combine synergistically to favor drought.

13.
J Biosci Bioeng ; 121(3): 247-52, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26272416

RESUMEN

Industrial yeasts are generally unable to sporulate but treatment with the immunosuppressive drug rapamycin restores this ability in a sake yeast strain Kyokai no. 7 (K7), Saccharomyces cerevisiae. This finding suggests that TORC1 is active under sporulation conditions. Here, using a reporter gene assay, Northern and Western blots, we tried to gain insight into how TORC1 function under nitrogen starvation conditions in K7 cells. Similarly to a laboratory strain, RPS26A transcription was repressed and Npr1 was dephosphorylated in K7 cells, indicative of the expected loss of TORC1 function under nitrogen starvation. The expression of nitrogen catabolite repression-sensitive genes, however, was not induced, the level of Cln3 remained constant, and autophagy was more slowly induced than in a laboratory strain, all suggestive of active TORC1. We conclude that TORC1 activity is partially reduced under nitrogen starvation conditions in K7 cells.


Asunto(s)
Bebidas Alcohólicas/microbiología , Complejos Multiproteicos/metabolismo , Nitrógeno/metabolismo , Saccharomyces cerevisiae/metabolismo , Serina-Treonina Quinasas TOR/metabolismo , Autofagia/efectos de los fármacos , Represión Catabólica/genética , Ciclinas/metabolismo , Regulación Fúngica de la Expresión Génica/efectos de los fármacos , Diana Mecanicista del Complejo 1 de la Rapamicina , Nitrógeno/farmacología , Fosforilación/efectos de los fármacos , Proteínas Quinasas/metabolismo , Saccharomyces cerevisiae/efectos de los fármacos , Proteínas de Saccharomyces cerevisiae/metabolismo , Sirolimus/farmacología , Esporas Fúngicas/efectos de los fármacos , Transcripción Genética/efectos de los fármacos
14.
J Biosci Bioeng ; 120(5): 562-9, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25817697

RESUMEN

We previously reported that transcripts encoding the homeoprotein EGAM1N are expressed in preimplantation mouse embryos and embryonic stem (ES) cells, and the exogenous expression of EGAM1N inhibits the differentiation of ES cells. In order to clarify the relationship between the inhibition of differentiation and EGAM1N, we generated mouse MG1.19 ES cells stably expressing EGAM1N. Control transfectants with an empty vector formed relatively flattened cell colonies similar to those observed in parental MG1.19 cells. In contrast, Egam1n transfectants formed tightly aggregated cell colonies with increased localization of CDH1 at cell-to-cell interfaces. The protein levels of pluripotency factors, including TBX3 and SOX2, were also increased. The expression of Tbx3 transcripts was induced, although the level of Sox2 transcripts was almost unchanged. The expression of EGAM1N resulted in no obvious changes in the expression of genes encoding receptors, protein kinases, transcription factors, and their encoded proteins involved in the LIF-STAT3 signaling pathway. Alkaline phosphatase activity, a marker for the undifferentiated state, in Egam1n transfectants was exhibited in a clonal proliferation assay. When differentiation of Egam1n transfectants was induced, progression was prevented with increases in transcript levels of Pou5f1, Sox2, Nanog, Klf4, Tbx3, and their encoded proteins. However, Egam1n transfectants formed relatively flattened-cell layers as observed in the control, indicating that the expression of EGAM1N could not maintain LIF-independent self-renewal of ES cells. Overall, we suggest that expression of EGAM1N could inhibit differentiation, at least in part, by elevating the protein levels of pluripotency factors in MG1.19 ES cells.


Asunto(s)
Diferenciación Celular/genética , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Células Madre Embrionarias de Ratones/citología , Células Madre Embrionarias de Ratones/metabolismo , Factores de Transcripción/metabolismo , Fosfatasa Alcalina/metabolismo , Animales , Proteínas Cdh1/metabolismo , Línea Celular , Autorrenovación de las Células , Forma de la Célula , Células Clonales/citología , Células Clonales/metabolismo , Perfilación de la Expresión Génica , Factor 4 Similar a Kruppel , Factores de Transcripción de Tipo Kruppel/genética , Factores de Transcripción de Tipo Kruppel/metabolismo , Factor Inhibidor de Leucemia/metabolismo , Ratones , Proteína Homeótica Nanog , Factor 3 de Transcripción de Unión a Octámeros/genética , Factor 3 de Transcripción de Unión a Octámeros/metabolismo , ARN Mensajero/metabolismo , Factores de Transcripción SOXB1/genética , Factores de Transcripción SOXB1/metabolismo , Factor de Transcripción STAT3/metabolismo , Transducción de Señal , Proteínas de Dominio T Box/genética , Proteínas de Dominio T Box/metabolismo , Transfección
15.
J Histochem Cytochem ; 63(5): 350-66, 2015 05.
Artículo en Inglés | MEDLINE | ID: mdl-25673289

RESUMEN

The expression of secretogranin III (SgIII) in chicken endocrine cells has not been investigated. There is limited data available for the immunohistochemical localization of SgIII in the brain, pituitary, and pancreatic islets of humans and rodents. In the present study, we used immunoblotting to reveal the similarities between the expression patterns of SgIII in the common endocrine glands of chickens and rats. The protein-protein interactions between SgIII and chromogranin A (CgA) mediate the sorting of CgA/prohormone core aggregates to the secretory granule membrane. We examined these interactions using co-immunoprecipitation in chicken endocrine tissues. Using immunohistochemistry, we also examined the expression of SgIII in a wide range of chicken endocrine glands and gastrointestinal endocrine cells (GECs). SgIII was expressed in the pituitary, pineal, adrenal (medullary parts), parathyroid, and ultimobranchial glands, but not in the thyroid gland. It was also expressed in GECs of the stomach (proventriculus and gizzard), small and large intestines, and pancreatic islet cells. These SgIII-expressing cells co-expressed serotonin, somatostatin, gastric inhibitory polypeptide, glucagon-like peptide-1, glucagon, or insulin. These results suggest that SgIII is expressed in the endocrine cells that secrete peptide hormones, which mature via the intragranular enzymatic processing of prohormones and physiologically active amines in chickens.


Asunto(s)
Cromograninas/metabolismo , Glándulas Endocrinas/metabolismo , Secuencia de Aminoácidos , Animales , Encéfalo/metabolismo , Pollos , Femenino , Tracto Gastrointestinal/metabolismo , Masculino , Ratones , Datos de Secuencia Molecular , Especificidad de Órganos , Ratas Wistar , Homología de Secuencia de Aminoácido
16.
Anal Chem ; 87(5): 2710-7, 2015 Mar 03.
Artículo en Inglés | MEDLINE | ID: mdl-25634116

RESUMEN

Small luminescent molecular probes based on the iridium(III) complex BTP, (btp)2Ir(acac) (btp = benzothienylpyridine, acac = acetylacetone) have been developed for sensing intracellular and in vivo O2. These compounds are BTPSA (containing an anionic carboxyl group), BTPNH2 (containing a cationic amino group), and BTPDM1 (containing a cationic dimethylamino group); all substituents are incorporated into the ancillary acetylacetonato ligand of BTP. Introduction of the cationic dimethylamino group resulted in an almost 20-fold increase in cellular uptake efficiency of BTPDM1 by HeLa cells compared with BTP. The phosphorescence intensity of BTPDM1 internalized in living cells provided a visual representation of the O2 gradient produced by placing a coverslip over cultured monolayer cells. The intracellular O2 levels (pO2) inside and outside the edge of the coverslip could be evaluated by measuring the phosphorescence lifetime of BTPDM1. Furthermore, intravenous administration of 25 nmol BTPDM1 to tumor-bearing mice allowed the tumor region to be visualized by BTPDM1 phosphorescence. The lifetime of BTPDM1 phosphorescence from tumor regions was much longer than that from extratumor regions, thereby demonstrating tumor hypoxia (pO2 = 6.1 mmHg for tumor and 50 mmHg for extratumor epidermal tissue). Tissue distribution studies showed that 2 h after injection of BTPDM1 into a mouse, the highest distribution was in liver and kidney, while after 24 h, BTPDM1 was excreted in the feces. These results demonstrate that BTPDM1 can be used as a small molecular probe for measuring intracellular O2 levels in both cultured cells and specific tissues and organs.


Asunto(s)
Técnicas Biosensibles/métodos , Iridio/química , Sustancias Luminiscentes/química , Neoplasias Experimentales/diagnóstico , Compuestos Organometálicos/química , Oxígeno/química , Animales , Femenino , Células HeLa , Humanos , Mediciones Luminiscentes , Células MCF-7 , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Neoplasias Experimentales/metabolismo
17.
Chemistry ; 20(20): 6054-60, 2014 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-24710805

RESUMEN

The effects of silyl and hydrophilic groups on the photodynamic properties of tetraphenylporphyrin (TPP) derivatives have been studied in vitro and in vivo. Silylation led to an improvement in the quantum yield of singlet oxygen sensitization for both sulfo and carboxy derivatives, although the silylation did not affect other photophysical properties. Silylation also improved the cellular uptake efficiency for both sulfo and carboxy derivatives, enhancing the in vitro photodynamic activity of the photosensitizer in U251 human glioma cells. The carboxy derivative (SiTPPC4 ) was found to show higher cellular uptake efficiency and in vitro photodynamic activity than the corresponding sulfo derivative (SiTPPS4 ), which indicates that the carboxy group is a more promising hydrophilic group than the sulfo group in the silylated porphyrin. SiTPPC4 was found to show high selective accumulation efficiency in tumors, although almost no tumor selectivity was observed for the nonsilylated porphyrin. The concentration of SiTPPC4 in tumors was 13 times higher than that in muscle 12 h after drug administration. We also studied tumor response after treatment and found that silylation enhanced in vivo photodynamic activity significantly. SiTPPC4 shows higher photodynamic activity than NPe6 with white light irradiation.


Asunto(s)
Neoplasias Encefálicas/tratamiento farmacológico , Glioma/tratamiento farmacológico , Fármacos Fotosensibilizantes/química , Fármacos Fotosensibilizantes/uso terapéutico , Porfirinas/química , Porfirinas/uso terapéutico , Animales , Encéfalo/efectos de los fármacos , Encéfalo/patología , Neoplasias Encefálicas/patología , Línea Celular Tumoral , Femenino , Fluorescencia , Glioma/patología , Humanos , Ratones , Ratones Desnudos , Fármacos Fotosensibilizantes/farmacocinética , Fármacos Fotosensibilizantes/farmacología , Porfirinas/farmacocinética , Porfirinas/farmacología , Silanos/química , Silanos/farmacocinética , Silanos/farmacología , Silanos/uso terapéutico
18.
Mol Cell Endocrinol ; 385(1-2): 88-96, 2014 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-24121198

RESUMEN

In contrast to the widely accepted images of the Golgi apparatus as a cup-like shape, the Golgi in pituitary gonadotropes is organized as a spherical shape in which the outer and inner faces are cis- and trans-Golgi elements, respectively. At the center of the spherical Golgi, a pair of centrioles is situated as a microtubule-organizing center from which radiating microtubules isotropically extend toward the cell periphery. This review focuses on the significance of the characteristic organization of the Golgi and microtubule network in gonadotropes, considering the roles of microtubule-dependent membrane transport in the formation and maintenance of the Golgi structure. Because the highly symmetrical organization of the Golgi is possibly perturbed in response to experimental treatments of gonadotropes, monitoring of the Golgi structure in gonadotropes under various experimental conditions will be a novel in vivo approach to elucidate the biogenesis of the Golgi apparatus.


Asunto(s)
Aparato de Golgi/metabolismo , Gonadotrofos/metabolismo , Microtúbulos/metabolismo , Animales , Gonadotrofos/citología , Humanos
19.
Ecol Evol ; 3(6): 1798-807, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23789086

RESUMEN

Reports indicate that leaf onset (leaf flush) of deciduous trees in cool-temperate ecosystems is occurring earlier in the spring in response to global warming. In this study, we created two types of phenology models, one driven only by warmth (spring warming [SW] model) and another driven by both warmth and winter chilling (parallel chill [PC] model), to predict such phenomena in the Japanese Islands at high spatial resolution (500 m). We calibrated these models using leaf onset dates derived from satellite data (Terra/MODIS) and in situ temperature data derived from a dense network of ground stations Automated Meteorological Data Acquisition System. We ran the model using future climate predictions created by the Japanese Meteorological Agency's MRI-AGCM3.1S model. In comparison to the first decade of the 2000s, our results predict that the date of leaf onset in the 2030s will advance by an average of 12 days under the SW model and 7 days under the PC model throughout the study area. The date of onset in the 2090s will advance by 26 days under the SW model and by 15 days under the PC model. The greatest impact will occur on Hokkaido (the northernmost island) and in the central mountains.

20.
J Biosci Bioeng ; 116(2): 141-6, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23510645

RESUMEN

Recently, we identified the structurally related homeoproteins EGAM1, EGAM1N, and EGAM1C in both preimplantation mouse embryos and mouse embryonic stem (ES) cells. These EGAM1 homeoproteins act as positive or negative regulators of differentiation and cell growth in mouse ES cells, such that these proteins are considered transcriptional regulators. In this study, we investigated their nuclear localization and identified the amino acid residues crucial for the nuclear translocation of EGAM1 and EGAM1C. When expressed exogenously in pluripotent ES cells and somatic NIH3T3 cells, all EGAM1 homeoproteins localized to the nucleus. Analysis using the web-based tool PSORTII predicted a potential nuclear localization signal (NLS) motif, RKDLIRSWFITQRHR, in the homeodomain shared by EGAM1 and EGAM1C. The introduction of mutations, such as mutations from K or R, both basic amino acid residues, to A, in this potential NLS resulted in significant impairment of the nuclear localization of both EGAM1 and EGAM1C. In contrast, GFP fusion proteins of all the full-length EGAM1 homeoproteins failed to localize to the nucleus. These results, when taken together, suggest that basic amino acid residues in the common homeodomain of EGAM1 and EGAM1C and the intact structures of the EGAM1 homeoproteins contribute, at least in part, to the nuclear localization of these proteins in mouse ES cells.


Asunto(s)
Aminoácidos Básicos/química , Núcleo Celular/metabolismo , Células Madre Embrionarias/metabolismo , Proteínas de Homeodominio/química , Proteínas de Homeodominio/metabolismo , Secuencia de Aminoácidos , Animales , Línea Celular , Proteínas Fluorescentes Verdes/genética , Proteínas de Homeodominio/genética , Ratones , Datos de Secuencia Molecular , Células 3T3 NIH , Señales de Localización Nuclear , Estructura Terciaria de Proteína
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