Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 97
Filtrar
1.
BMB Rep ; 56(11): 584-593, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37915135

RESUMEN

Hypoxia, a widespread occurrence observed in various malignant tumors, results from rapid tumor growth that outpaces the oxygen supply. Tumor hypoxia precipitates several effects on tumor biology; these include activating angiogenesis, intensifying invasiveness, enhancing the survival of tumor cells, suppressing anti-tumor immunity, and fostering resistance to therapy. Aligned with the findings that correlate CMGC kinases with the regulation of Hypoxia-Inducible Factor (HIF), a pivotal modulator, reports also indicate that hypoxia governs the activity of CMGC kinases, including DYRK1 kinases. Prolyl hydroxylation of DYRK1 kinases by PHD1 constitutes a novel mechanism of kinase maturation and activation. This modification "primes" DYRK1 kinases for subsequent tyrosine autophosphorylation, a vital step in their activation cascade. This mechanism adds a layer of intricacy to comprehending the regulation of CMGC kinases, and underscores the complex interplay between distinct post-translational modifications in harmonizing precise kinase activity. Overall, hypoxia assumes a substantial role in cancer progression, influencing diverse aspects of tumor biology that include angiogenesis, invasiveness, cell survival, and resistance to treatment. CMGC kinases are deeply entwined in its regulation. To fathom the molecular mechanisms underpinning hypoxia's impact on cancer cells, comprehending how hypoxia and prolyl hydroxylation govern the activity of CMGC kinases, including DYRK1 kinases, becomes imperative. This insight may pave the way for pioneering therapeutic approaches that target the hypoxic tumor microenvironment and its associated challenges. [BMB Reports 2023; 56(11): 584-593].


Asunto(s)
Hipoxia , Neoplasias , Humanos , Neoplasias/terapia , Fosforilación , Hipoxia de la Célula , Procesamiento Proteico-Postraduccional , Subunidad alfa del Factor 1 Inducible por Hipoxia , Microambiente Tumoral
2.
Biochem Biophys Res Commun ; 653: 126-132, 2023 04 23.
Artículo en Inglés | MEDLINE | ID: mdl-36868076

RESUMEN

Obesity is commonly associated with excessive adipogenesis, a process by which preadipocytes undergo differentiation into mature adipocytes; however, the mechanisms underlying adipogenesis are not completely understood. Potassium channel tetramerization domain-containing 17 (Kctd17) belongs to the Kctd superfamily and act as a substrate adaptor of the Cullin 3-RING E3 ubiquitin ligase, which is involved in a wide variety of cell functions. However, its function in the adipose tissue remains largely unknown. Here, we found that Kctd17 expression levels were increased in white adipose tissue, especially in adipocytes, in obese mice compared to lean control mice. Gain or loss of function of Kctd17 in preadipocytes inhibited or promoted adipogenesis, respectively. Furthermore, we found that Kctd17 bound to C/EBP homologous protein (Chop) to target it for ubiquitin-mediated degradation, and this process was likely associated with increased adipogenesis. In conclusion, these data suggest that Kctd17 plays an important role in adipogenesis and can be a novel therapeutic target for obesity.


Asunto(s)
Adipogénesis , Tejido Adiposo , Animales , Ratones , Células 3T3-L1 , Adipocitos/metabolismo , Adipogénesis/fisiología , Tejido Adiposo/metabolismo , Diferenciación Celular , Obesidad/genética , Obesidad/metabolismo
3.
Gastroenterology ; 164(3): 439-453, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36402191

RESUMEN

BACKGROUND & AIMS: Obesity predisposes to type 2 diabetes (T2D) and nonalcoholic fatty liver disease (NAFLD), but underlying mechanisms are incompletely understood. Potassium channel tetramerization domain-containing protein 17 (Kctd17) levels are increased in livers from obese mice and humans. In this study, we investigated the mechanism of increased Kctd17 and whether it is causal to obesity-induced metabolic complications. METHODS: We transduced Rosa26-LSL-Cas9 knockin mice with AAV8-TBG-Cre (Control), AAV8-U6-Kctd17 sgRNA-TBG-Cre (L-Kctd17), AAV8-U6-Oga sgRNA-TBG-Cre (L-Oga), or AAV8-U6-Kctd17/Oga sgRNA-TBG-Cre (DKO). We fed mice a high-fat diet (HFD) and assessed for hepatic glucose and lipid homeostasis. We generated Kctd17, O-GlcNAcase (Oga), or Kctd17/Oga-knockout hepatoma cells by CRISPR-Cas9, and Kctd17-directed antisense oligonucleotide to test therapeutic potential in vivo. We analyzed transcriptomic data from patients with NAFLD. RESULTS: Hepatocyte Kctd17 expression was increased in HFD-fed mice due to increased Srebp1c activity. HFD-fed L-Kctd17 or Kctd17 antisense oligonucleotide-treated mice show improved glucose tolerance and hepatic steatosis, whereas forced Kctd17 expression caused glucose intolerance and hepatic steatosis even in lean mice. Kctd17 induced Oga degradation, resulting in increasing carbohydrate response element-binding protein (Chrebp) protein, so concomitant Oga knockout negated metabolic benefits of hepatocyte Kctd17 deletion. In patients with NAFLD, KCTD17 messenger RNA was positively correlated with expression of Chrebp target and other lipogenic genes. CONCLUSIONS: Srebp1c-induced hepatocyte Kctd17 expression in obesity disrupted glucose and lipid metabolism by stabilizing Chrebp, and may represent a novel therapeutic target for obesity-induced T2D and NAFLD.


Asunto(s)
Diabetes Mellitus Tipo 2 , Intolerancia a la Glucosa , Resistencia a la Insulina , Enfermedad del Hígado Graso no Alcohólico , Humanos , Animales , Ratones , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Diabetes Mellitus Tipo 2/complicaciones , Resistencia a la Insulina/fisiología , Factores de Transcripción/genética , Hígado/metabolismo , Hepatocitos/metabolismo , Obesidad/complicaciones , Glucosa/metabolismo , Dieta Alta en Grasa , Ratones Endogámicos C57BL , Proteínas Adaptadoras Transductoras de Señales/metabolismo
4.
J Orthop Translat ; 37: 100-112, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36262961

RESUMEN

Background: The osteogenic capabilities and biodegradability of octacalcium phosphate (OCP) composites make them unique. Despite the excellent characteristics of OCP, their use is limited due to handling difficulties. In this study, we aimed to evaluate and compare three types of OCPs (cemented OCP (C-OCP), C-OCP with collagen (OCP/Col), and synthetic OCP (S-OCP) with alginate (OCP/Alg)) versus commercially available ß-tricalcium phosphate (ß-TCP) regarding their potential to accelerate bone formation in defective rat tibias. Methods: The specimens with OCP composite were manufactured into 5 â€‹mm cubes and inserted into the segmental defects of rat tibias fixed with an external fixator. In addition, 3 â€‹mm-hole defects in rat tibias were evaluated to compare the graft material properties in different clinical situations. Serial X-ray studies were evaluated weekly and the tibias were harvested at postoperative 6 weeks or 8 weeks for radiologic evaluation. Histological and histomorphometric analyses were performed to evaluate the acceleration of bone formation. Results: In the critical-defect model, OCP/Alg showed bone bridges between segmentally resected bone ends that were comparable to those of ß-TCP. However, differences were observed in the residual graft materials. Most ß-TCP was maintained until 8 weeks postoperatively; however, OCP/Alg was more biodegradable. In addition calcification in the ß-TCP occurred at the directly contacted area between graft particles and bony ingrowth was observed in the region adjacent resected surface of tibia. In contrast, no direct bony ingrowth was observed in OCP-based materials, but osteogenesis induced from resected surface of tibia was more active. In the hole-defect model, OCP/Col accelerated bone formation. ß-TCP and OCP/Alg showed similar patterns with relatively higher biodegradability. In histology, among the OCP-based materials, directly contacted new bone was formed only in OCP/Alg group. The new bone formation in the periphery area of graft materials was much more active in the OCP-based materials, and the newly formed bone showed a thicker trabecular and more mature appearance than the ß-TCP group. Conclusions: In this study, OCP/Alg was equivalent to ß-TCP in the acceleration of bone formation with better biodegradability appropriate for clinical situations in different circumstances. Our OCP/Col composite showed fast degradation, which makes it unsuitable for use in mechanical stress conditions in clinical orthopedic settings. The Translational Potential of this Article: In our research, we compared our various manufactured OCP composites to commercially available ß-TCP in critical-defect rat tibia model. OCP/Col showed acceleration in hole-defect model as previous studies in dental field but in our critical-sized defect model it resorbed fast without acceleration of bony union. OCP/Alg showed matched results compared to ß-TCP and relatively fast resorption so we showed market value in special clinical indication depending on treatment strategy. This is the first OCP composite study in orthopaedics with animal critical-sized tibia bone study and further study should be considered for clinical application based on this study.

5.
Nat Commun ; 13(1): 2089, 2022 04 19.
Artículo en Inglés | MEDLINE | ID: mdl-35440621

RESUMEN

Tissue-specific transcriptional activity is silenced in mitotic cells but it remains unclear whether the mitotic regulatory machinery interacts with tissue-specific transcriptional programs. We show that such cross-talk involves the controlled interaction between core subunits of the anaphase-promoting complex (APC) and the ID2 substrate. The N-terminus of ID2 is independently and structurally compatible with a pocket composed of core APC/C subunits that may optimally orient ID2 onto the APCCDH1 complex. Phosphorylation of serine-5 by CDK1 prevented the association of ID2 with core APC, impaired ubiquitylation and stabilized ID2 protein at the mitosis-G1 transition leading to inhibition of basic Helix-Loop-Helix (bHLH)-mediated transcription. The serine-5 phospho-mimetic mutant of ID2 that inefficiently bound core APC remained stable during mitosis, delayed exit from mitosis and reloading of bHLH transcription factors on chromatin. It also locked cells into a "mitotic stem cell" transcriptional state resembling the pluripotent program of embryonic stem cells. The substrates of APCCDH1 SKP2 and Cyclin B1 share with ID2 the phosphorylation-dependent, D-box-independent interaction with core APC. These results reveal a new layer of control of the mechanism by which substrates are recognized by APC.


Asunto(s)
Anafase , Proteínas de Ciclo Celular , Ciclosoma-Complejo Promotor de la Anafase/genética , Proteínas de Ciclo Celular/metabolismo , Mitosis , Serina
6.
BMB Rep ; 54(9): 451-457, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34353431

RESUMEN

Over the last decades, research has focused on the role of pleckstrin homology (PH) domain leucine-rich repeat protein phosphatases (PHLPPs) in regulating cellular signaling via PI3K/Akt inhibition. The PKB/Akt signaling imbalances are associated with a variety of illnesses, including various types of cancer, inflammatory response, insulin resistance, and diabetes, demonstrating the relevance of PHLPPs in the prevention of diseases. Furthermore, identification of novel substrates of PHLPPs unveils their role as a critical mediator in various cellular processes. Recently, researchers have explored the increasing complexity of signaling networks involving PHLPPs whereby relevant information of PHLPPs in metabolic diseases was obtained. In this review, we discuss the current knowledge of PHLPPs on the well-known substrates and metabolic regulation, especially in liver, pancreatic beta cell, adipose tissue, and skeletal muscle in relation with the stated diseases. Understanding the context-dependent functions of PHLPPs can lead to a promising treatment strategy for several kinds of metabolic diseases. [BMB Reports 2021; 54(9): 451-457].


Asunto(s)
Fosfoproteínas Fosfatasas/metabolismo , Tejido Adiposo/metabolismo , Humanos , Resistencia a la Insulina , Hígado/metabolismo , Enfermedades Metabólicas/metabolismo , Enfermedades Metabólicas/patología , Fosfatidilinositol 3-Quinasas/metabolismo , Fosfoproteínas Fosfatasas/química , Fosfoproteínas Fosfatasas/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal , Especificidad por Sustrato
7.
BMB Rep ; 54(6): 329-334, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34078526

RESUMEN

Collagen type I is the most abundant form of collagen in human tissues, and is composed of two identical α-1 type I chains and an α-2 type I chain organized in a triple helical structure. A previous study has shown that human collagen α-2 type I (hCOL1A2) promotes collagen synthesis, wound healing, and elastin production in normal human dermal fibroblasts (HDFs). However, the biological effects of human collagen α-1 type I (hCOL1A1) on various skin properties have not been investigated. Here, we isolate and identify the hCOL1A1-collagen effective domain (CED) which promotes collagen type I synthesis. Recombinant hCOL1A1-CED effectively induces cell proliferation and collagen biosynthesis in HDFs, as well as increased cell migration and elastin production. Based on these results, hCOL1A1-CED may be explored further for its potential use as a preventative agent against skin aging. [BMB Reports 2021; 54(6): 329-334].


Asunto(s)
Cadena alfa 1 del Colágeno Tipo I/metabolismo , Colágeno/metabolismo , Elastina/metabolismo , Fibroblastos/metabolismo , Piel/metabolismo , Movimiento Celular , Proliferación Celular , Células Cultivadas , Cadena alfa 1 del Colágeno Tipo I/genética , Fibroblastos/citología , Humanos , Piel/citología , Cicatrización de Heridas
8.
Nat Commun ; 12(1): 1822, 2021 03 23.
Artículo en Inglés | MEDLINE | ID: mdl-33758172

RESUMEN

Increased adiposity confers risk for systemic insulin resistance and type 2 diabetes (T2D), but mechanisms underlying this pathogenic inter-organ crosstalk are incompletely understood. We find PHLPP2 (PH domain and leucine rich repeat protein phosphatase 2), recently identified as the Akt Ser473 phosphatase, to be increased in adipocytes from obese mice. To identify the functional consequence of increased adipocyte PHLPP2 in obese mice, we generated adipocyte-specific PHLPP2 knockout (A-PHLPP2) mice. A-PHLPP2 mice show normal adiposity and glucose metabolism when fed a normal chow diet, but reduced adiposity and improved whole-body glucose tolerance as compared to Cre- controls with high-fat diet (HFD) feeding. Notably, HFD-fed A-PHLPP2 mice show increased HSL phosphorylation, leading to increased lipolysis in vitro and in vivo. Mobilized adipocyte fatty acids are oxidized, leading to increased peroxisome proliferator-activated receptor alpha (PPARα)-dependent adiponectin secretion, which in turn increases hepatic fatty acid oxidation to ameliorate obesity-induced fatty liver. Consistently, adipose PHLPP2 expression is negatively correlated with serum adiponectin levels in obese humans. Overall, these data implicate an adipocyte PHLPP2-HSL-PPARα signaling axis to regulate systemic glucose and lipid homeostasis, and suggest that excess adipocyte PHLPP2 explains decreased adiponectin secretion and downstream metabolic consequence in obesity.


Asunto(s)
Adipocitos/metabolismo , Tejido Adiposo/metabolismo , Hígado Graso/prevención & control , Resistencia a la Insulina/genética , Metabolismo de los Lípidos/genética , Obesidad/metabolismo , Fosfoproteínas Fosfatasas/deficiencia , Adiponectina/metabolismo , Adiposidad/genética , Animales , Dieta Alta en Grasa , Ácidos Grasos/metabolismo , Hígado Graso/genética , Hígado Graso/metabolismo , Regulación de la Expresión Génica/genética , Glucosa/metabolismo , Homeostasis , Humanos , Lipólisis/genética , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Obesos , Obesidad/genética , Obesidad/patología , PPAR alfa/metabolismo , Fosfoproteínas Fosfatasas/genética , Fosfoproteínas Fosfatasas/metabolismo , Fosforilación , Transducción de Señal/genética , Esterol Esterasa/metabolismo
9.
Polymers (Basel) ; 14(1)2021 Dec 23.
Artículo en Inglés | MEDLINE | ID: mdl-35012059

RESUMEN

Changes in intraoral pH can cause changes in the chemical decomposition and surface properties of treated resin-based pits and fissure sealants (sealant). The purpose of this study is to evaluate the release of bisphenol A (BPA) from sealants under three different pH conditions over time. The test specimen was applied with 6 sealants 5 mg each on a glass plate (10 × 10 mm) and photopolymerized. The samples were immersed for 10 min, 1 h, and 24 h in solutions of pH 3.0, 6.5, and 10.0 at 37 °C. BPA release was measured using a gas chromatography-mass spectrometer. A statistical analysis was performed by two-way ANOVA and one-way ANOVA to verify the effect of pH conditions and time on BPA release. The BPA concentration in the pH 3.0 group was higher at all points than with pH 6.5 and pH 10.0 (p < 0.05), and gradually increased over time (p < 0.05). As a result, it was confirmed that low pH negatively influences BPA release. Therefore, frequent exposure to low pH due to the consumption of various beverages after sealant treatment can negatively affect the sealant's chemical stability in the oral cavity.

10.
BMB Rep ; 53(10): 539-544, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32843132

RESUMEN

Skin aging appears to be the result of overlapping intrinsic (including genetic and hormonal factors) and extrinsic (external environment including chronic light exposure, chemicals, and toxins) processes. These factors cause decreases in the synthesis of collagen type I and elastin in fibroblasts and increases in the melanin in melanocytes. Collagen Type I is the most abundant type of collagen and is a major structural protein in human body tissues. In previous studies, many products containing collagen derived from land and marine animals as well as other sources have been used for a wide range of purposes in cosmetics and food. However, to our knowledge, the effects of human collagenderived peptides on improvements in skin condition have not been investigated. Here we isolate and identify the domain of a human COL1A2-derived protein which promotes fibroblast cell proliferation and collagen type I synthesis. This human COL 1A2-derived peptide enhances wound healing and elastin production. Finally, the human collagen alpha-2 type I-derived peptide (SMM) ameliorates collagen type I synthesis, cell proliferation, cell migration, and elastin synthesis, supporting a significant anti-wrinkle effect. Collectively, these results demonstrate that human collagen alpha-2 type I-derived peptides is practically accessible in both cosmetics and food, with the goal of improving skin condition. [BMB Reports 2020; 53(10): 539-544].


Asunto(s)
Colágeno Tipo I/metabolismo , Fibroblastos/metabolismo , Piel/metabolismo , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Colágeno/biosíntesis , Colágeno/metabolismo , Colágeno Tipo I/fisiología , Elastina/biosíntesis , Elastina/metabolismo , Elastina/farmacología , Humanos , Envejecimiento de la Piel/fisiología , Cicatrización de Heridas/fisiología
11.
Mol Cell ; 79(3): 376-389.e8, 2020 08 06.
Artículo en Inglés | MEDLINE | ID: mdl-32640193

RESUMEN

Activation of dual-specificity tyrosine-phosphorylation-regulated kinases 1A and 1B (DYRK1A and DYRK1B) requires prolyl hydroxylation by PHD1 prolyl hydroxylase. Prolyl hydroxylation of DYRK1 initiates a cascade of events leading to the release of molecular constraints on von Hippel-Lindau (VHL) ubiquitin ligase tumor suppressor function. However, the proline residue of DYRK1 targeted by hydroxylation and the role of prolyl hydroxylation in tyrosine autophosphorylation of DYRK1 are unknown. We found that a highly conserved proline in the CMGC insert of the DYRK1 kinase domain is hydroxylated by PHD1, and this event precedes tyrosine autophosphorylation. Mutation of the hydroxylation acceptor proline precludes tyrosine autophosphorylation and folding of DYRK1, resulting in a kinase unable to preserve VHL function and lacking glioma suppression activity. The consensus proline sequence is shared by most CMGC kinases, and prolyl hydroxylation is essential for catalytic activation. Thus, formation of prolyl-hydroxylated intermediates is a novel mechanism of kinase maturation and likely a general mechanism of regulation of CMGC kinases in eukaryotes.


Asunto(s)
Neoplasias Encefálicas/genética , Glioma/genética , Isoenzimas/genética , Prolina/metabolismo , Procesamiento Proteico-Postraduccional , Proteínas Serina-Treonina Quinasas/genética , Proteínas Tirosina Quinasas/genética , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/genética , Secuencia de Aminoácidos , Animales , Sitios de Unión , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patología , Línea Celular Tumoral , Cristalografía por Rayos X , Regulación Neoplásica de la Expresión Génica , Glioma/metabolismo , Glioma/patología , Células HEK293 , Xenoinjertos , Humanos , Hidroxilación , Prolina Dioxigenasas del Factor Inducible por Hipoxia/genética , Prolina Dioxigenasas del Factor Inducible por Hipoxia/metabolismo , Isoenzimas/química , Isoenzimas/metabolismo , Ratones , Ratones Desnudos , Proteína Quinasa 14 Activada por Mitógenos/química , Proteína Quinasa 14 Activada por Mitógenos/genética , Proteína Quinasa 14 Activada por Mitógenos/metabolismo , Modelos Moleculares , Mutación , Neuroglía/metabolismo , Neuroglía/patología , Fosforilación , Unión Proteica , Dominios y Motivos de Interacción de Proteínas , Proteínas Serina-Treonina Quinasas/química , Proteínas Serina-Treonina Quinasas/metabolismo , Estructura Secundaria de Proteína , Proteínas Tirosina Quinasas/química , Proteínas Tirosina Quinasas/metabolismo , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/metabolismo , Quinasas DyrK
13.
Cell Rep ; 29(1): 62-75.e7, 2019 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-31577956

RESUMEN

Id helix-loop-helix (HLH) proteins (Id1-4) bind E protein bHLH transcription factors, preventing them from forming active transcription complexes that drive changes in cell states. Id proteins are primarily expressed during development to inhibit differentiation, but they become re-expressed in adult tissues in diseases of the vasculature and cancer. We show that the genetic loss of Id1/Id3 reduces ocular neovascularization in mouse models of wet age-related macular degeneration (AMD) and retinopathy of prematurity (ROP). An in silico screen identifies AGX51, a small-molecule Id antagonist. AGX51 inhibits the Id1-E47 interaction, leading to ubiquitin-mediated degradation of Ids, cell growth arrest, and reduced viability. AGX51 is well-tolerated in mice and phenocopies the genetic loss of Id expression in AMD and ROP models by inhibiting retinal neovascularization. Thus, AGX51 is a first-in-class compound that antagonizes an interaction formerly considered undruggable and that may have utility in the management of multiple diseases.


Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Neovascularización Patológica/tratamiento farmacológico , Bibliotecas de Moléculas Pequeñas/farmacología , Animales , Línea Celular , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Femenino , Células HCT116 , Células HEK293 , Células Endoteliales de la Vena Umbilical Humana , Humanos , Proteína 1 Inhibidora de la Diferenciación/metabolismo , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Desnudos , Neovascularización Patológica/metabolismo
14.
J Biol Chem ; 294(42): 15435-15445, 2019 10 18.
Artículo en Inglés | MEDLINE | ID: mdl-31471318

RESUMEN

Akt signaling is an important regulator of neural development, but the distinctive function of Akt isoforms in brain development presents a challenge. Here we show Siah1 as an ubiquitin ligase that preferentially interacts with Akt3 and facilitates ubiquitination and degradation of Akt3. Akt3 is enriched in the axonal shaft and branches but not growth cone tips, where Siah1 is prominently present. Depletion of Siah1 enhanced Akt3 levels in the soma and axonal tips, eliciting multiple branching. Brain-specific somatic mutation in Akt3-E17K escapes from Siah1-mediated degradation and causes improper neural development with dysmorphic neurons. Remarkably, coexpression of Siah1 with Akt3-WT restricted disorganization of neural development is caused by Akt3 overexpression, whereas forced expression of Siah1 with the Akt3-E17K mutant fails to cope with malformation of neural development. These findings demonstrate that Siah1 limits Akt3 turnover during brain development and that this event is essential for normal organization of the neural network.


Asunto(s)
Encéfalo/crecimiento & desarrollo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Animales , Axones/metabolismo , Encéfalo/metabolismo , Ratones , Neurogénesis , Neuronas/metabolismo , Proteolisis , Proteínas Proto-Oncogénicas c-akt/genética , Ratas , Ubiquitina/metabolismo , Ubiquitina-Proteína Ligasas/genética , Ubiquitinación
15.
Front Physiol ; 10: 1062, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31481899

RESUMEN

Many studies have demonstrated that an alteration in hemorheological properties is closely correlated with diabetic microcirculatory diseases. However, most of these studies have been limited to animal studies or used a small number of clinical samples, due to a lack of effective point-of-care (POC) devices to measure such properties within clinical environments. Owing to recent developments in microfluidic technology, several hemorheological POC devices have been designed that allow for the possibility of conducting extensive clinical studies using hemorheological measurements. Here, we reviewed recent clinical studies of diabetic kidney disease (DKD) associated with hemorheological parameters. We found that RBC deformability alone did not show a significant difference according to the degree of DKD, whereas critical shear stress (CSS) was found to be closely related to the ratio of albumin to creatinine and glomerular filtration rate. We also reviewed studies that alteration of hemorheological properties are associated with the development of DKD, which showed that CSS could be considered as a potential index to diagnose other diabetic complications as well as DKD.

16.
Endocrinol Metab (Seoul) ; 34(2): 179-186, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31257745

RESUMEN

BACKGROUND: Recently, the triglyceride glucose (TyG) index has been considered a surrogate marker of insulin resistance which is a well-known pathogenic factor in nonalcoholic fatty liver disease (NAFLD). However, few studies have investigated the relationship between the TyG index and NAFLD. Thus, we investigated the relationship between the TyG index and NAFLD and the effectiveness of the TyG index compared with the homeostasis model assessment of insulin resistance (HOMA-IR) in identifying NAFLD in Korean adults. METHODS: Participants of 4,986 who underwent ultrasonography in a health promotion center were enrolled. The TyG index was calculated as ln [fasting triglycerides (mg/dL)×fasting glucose (mg/dL)/2], and HOMA-IR was estimated. NAFLD was diagnosed by ultrasonography. RESULTS: Significant differences were observed in metabolic parameters among the quartiles of the TyG index. The prevalence of NAFLD significantly increased with increment in the TyG index. After adjusting for multiple risk factors, a logistic regression analysis was performed. When the highest and lowest quartiles of the TyG index and HOMA-IR were compared, the odds ratios for the prevalence of NAFLD were 2.94 and 1.93 (95% confidence interval, 2.32 to 3.72 and 1.43 to 2.61; both P for trend <0.01), respectively. According to the receiver operating characteristic analysis, the TyG index was superior to HOMA-IR in predicting NAFLD. CONCLUSION: The TyG index and prevalence of NAFLD were significantly related and the TyG index was superior to HOMA-IR in predicting NAFLD in Korean adults.


Asunto(s)
Glucemia/análisis , Resistencia a la Insulina , Enfermedad del Hígado Graso no Alcohólico/sangre , Enfermedad del Hígado Graso no Alcohólico/diagnóstico , Triglicéridos/análisis , Triglicéridos/sangre , Biomarcadores/sangre , Femenino , Homeostasis , Humanos , Masculino , Persona de Mediana Edad , República de Corea
17.
Diabetes Care ; 42(8): 1569-1573, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31182490

RESUMEN

OBJECTIVE: To investigate the triglyceride-glucose (TyG) index association with coronary artery calcification (CAC) progression in adult Koreans. RESEARCH DESIGN AND METHODS: Various cardiovascular risk factors and anthropometric profiles were assessed in 1,175 subjects who previously had a CAC evaluation at least twice by multidetector computed tomography in a health care center. The TyG index was determined using ln(fasting triglycerides [mg/dL] × fasting glucose [mg/dL]/2). The CAC progression was defined as either incident CAC in a CAC-free population at baseline or an increase of ≥2.5 units between the square roots of the baseline and follow-up coronary artery calcium scores (CACSs) of subjects with detectable CAC at baseline. RESULTS: CAC progression was seen in 312 subjects (27%) during 4.2 years follow-up. On the basis of the TyG index, subjects were stratified into three groups. Follow-up CACS and incidence of CAC progression were markedly elevated with rising TyG index tertile. Logistic regression analysis adjusted for various risk factors revealed an odds ratio for CAC progression of 1.82 (95% CI 1.20-2.77; P ≤ 0.01) when the highest and lowest TyG index tertiles were compared. CONCLUSIONS: The TyG index is an independent predictor of CAC progression.


Asunto(s)
Glucemia/análisis , Enfermedad de la Arteria Coronaria/diagnóstico , Indicadores de Salud , Triglicéridos/sangre , Calcificación Vascular/diagnóstico , Adulto , Glucemia/metabolismo , Enfermedad de la Arteria Coronaria/epidemiología , Enfermedad de la Arteria Coronaria/patología , Progresión de la Enfermedad , Ayuno/sangre , Femenino , Humanos , Incidencia , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Pronóstico , República de Corea/epidemiología , Estudios Retrospectivos , Factores de Riesgo , Triglicéridos/análisis , Calcificación Vascular/sangre , Calcificación Vascular/epidemiología
18.
Opt Express ; 27(10): 14283-14297, 2019 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-31163879

RESUMEN

The effects of ion clustering and excited state absorption occurring in holmium-doped fiber lasers are investigated experimentally and theoretically. It is found that the slope efficiencies of holmium-doped fiber lasers are reduced by inhomogeneous upconversion associated with the clustering of Ho3+ ions. Via theoretical analysis based upon Judd-Ofelt theory, it is also found that the effect of excited state absorption on the performance of Ho-doped fiber lasers is negligible, a fact indicating that ion clustering is the dominant cause of the lower-than-expected slope efficiencies observed in holmium-doped fiber lasers. We argue that ion clustering is an intrinsic flaw of holmium-doped fibers and is difficult to eliminate, because our research efforts are based on commercially available low-concentration fiber, which is fabricated with state-of-the-art techniques.

19.
J Diabetes Investig ; 10(5): 1223-1228, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30618112

RESUMEN

AIMS/INTRODUCTION: Natural killer (NK) cells are cytotoxic lymphocytes critical to human immunity. Previous studies showed correlations between NK cell function and blood glucose concentrations. The purpose of the present study was to assess the NK cell activity and various metabolic parameters in people with type 2 diabetes, prediabetes and normal glucose tolerance. MATERIALS AND METHODS: A total of 49 participants were enrolled in the study. Anthropometric and biochemical parameters including age, sex, body mass index, smoking status, blood pressure, fasting plasma glucose, C-peptide, insulin, glycated hemoglobin, total cholesterol, triglyceride, high-density lipoprotein cholesterol and low-density lipoprotein cholesterol were assessed. The 75 g oral glucose tolerance test was carried out for 2-h postload glucose level. Homeostatic model assessment was calculated for insulin resistance and ß-cell function. NK cell activity was measured by detecting the circulating interferon-gamma level secreted from NK cells. RESULTS: NK cell activity was lower in patients with type 2 diabetes (768.01 ± 650.35) compared with those with prediabetes (2,396.08 ± 653.76, P < 0.001) and normal glucose tolerance (2,435.31 ± 633.22, P < 0.001). In patients with type 2 diabetes, there was a significant inverse linear relationship between NK cell activity and fasting plasma glucose, glycated hemoglobin, and 2-h postload glucose level (all P < 0.001). Multiple regression analysis showed glycated hemoglobin to be an independent predictor of NK cell activity in patients with type 2 diabetes. CONCLUSIONS: Compared with individuals with normal glucose tolerance or prediabetes, type 2 diabetes patients have a reduced NK cell activity, and it is significantly related to glucose control.


Asunto(s)
Biomarcadores/análisis , Glucemia/metabolismo , Diabetes Mellitus Tipo 2/patología , Células Asesinas Naturales/inmunología , Estado Prediabético/patología , Estudios Transversales , Diabetes Mellitus Tipo 2/inmunología , Diabetes Mellitus Tipo 2/metabolismo , Femenino , Estudios de Seguimiento , Hemoglobina Glucada/análisis , Humanos , Masculino , Persona de Mediana Edad , Estado Prediabético/inmunología , Estado Prediabético/metabolismo , Pronóstico
20.
Clin Hemorheol Microcirc ; 72(1): 75-84, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30452406

RESUMEN

BACKGROUND AND OBJECTIVE: Hemorheologic alterations have been suggested to play a role in the pathogenesis of diabetic microvascular complications. We measured various hemorheologic parameters and assessed their possible role as a diagnostic tool for diabetic nephropathy (DN). METHODS: 248 subjects with type 2 diabetes and 222 subjects with prediabetes were included in this study. Hemorheologic parameters, including erythrocyte sedimentation rate (ESR), elongation index at 3 Pa (EI) were measured using microfluidic hemorheometer. Various metabolic parameters were measured from fasting blood samples. The subjects were stratified into three groups according to classification of DN by urinary albumin to creatinine ratio (ACR) and four groups by estimated glomerular filtration rate (GFR), than analyzed. RESULTS: Significant differences were observed in metabolic and hemorheologic parameters according to progression of DN. Among them, (Fibrinogen×ESR)/ EI differed in all three groups of urinary ACR. In multiple regression analysis, (Fibrinogen×ESR)/ EI was an independent predictor of urine ACR after adjusted with confounding factors (ß â€Š= 0.010, p < 0.001). (Fibrinogen×ESR)/ EI also showed significant difference no or minimal CKD stage, moderate CKD and severe CKD classified by GFR. This parameter showed area under curve (AUC) of the receiver operating characteristic (ROC) curve of 0.762, and moderate sensitivity and specificity to predict prevalence of microalbuminuria. CONCLUSIONS: (Fibrinogen×ESR)/ EI is a sensitive parameter for screening diabetic nephropathy.


Asunto(s)
Diabetes Mellitus Tipo 2/complicaciones , Nefropatías Diabéticas/diagnóstico , Deformación Eritrocítica/fisiología , Hemorreología , Estudios Transversales , Diabetes Mellitus Tipo 2/fisiopatología , Nefropatías Diabéticas/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...