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1.
PLoS One ; 18(4): e0284012, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37115796

RESUMEN

Cd248 has recently been associated with adipose tissue physiology, demonstrated by reduced weight gain in high fat diet-fed mice with genetic deletion of Cd248 relative to controls. Here we set out to determine the metabolic consequences of loss of Cd248. Strikingly, we find these to be sex specific; By subjecting Cd248-/- and Cd248+/+ mice to a high fat diet and indirect calorimetry study, we identified that only male Cd248-/- mice show reduced weight gain compared to littermate control wildtype mice. In addition, male (but not female) mice showed a lower respiratory exchange ratio on both chow and high fat diets, indicating a predisposition to metabolise lipid. Lipidomic studies on specific fat depots found reduced triglyceride and diglyceride deposition in male Cd248-/- mice, and this was supported by reduced expression of lipogenic and adipogenic genes. Finally, metabolomic analysis of isolated, differentiated preadipocytes found alterations in metabolic pathways associated with lipid deposition in cells isolated from male, but not female, Cd248-/- mice. Overall, our results highlight the importance of sex controls in animal studies and point to a role for Cd248 in sex- and depot-specific regulation of lipid metabolism.


Asunto(s)
Tejido Adiposo , Lipidómica , Animales , Femenino , Masculino , Ratones , Tejido Adiposo/metabolismo , Antígenos CD/metabolismo , Antígenos de Neoplasias/metabolismo , Dieta Alta en Grasa , Metabolismo de los Lípidos/genética , Ratones Endogámicos C57BL , Triglicéridos/metabolismo , Aumento de Peso
2.
J Dairy Sci ; 105(2): 1797-1814, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34799116

RESUMEN

The complex and interrelated management components of dairy farming are associated with health, production, and profitability of the herd, yet there is limited objective data on current management practices of the far-off, close-up, and fresh periods across Canadian dairy farms. We aimed to describe management practices of Canadian dairy farms by using a pre-existing risk assessment tool and outline potential management opportunities. Upon veterinarians' or producers' request, a transition management risk assessment (The Vital 90, Elanco) was performed by trained observers (n = 10) during farm visits (n = 78) between August 2014 and March 2018. Most farms were in Ontario (n = 64), whereas the remaining were in Alberta (n = 5), British Columbia (n = 4), Manitoba (n = 1), Prince Edward Island (n = 2), Newfoundland (n = 1), and Saskatchewan (n = 1). The study included 79 questions about nutrition, pen management, and cow comfort of the dry (approximate ranges: far-off, -60 to -20 d in milk; close-up, -20 to 0 d in milk) and fresh (0-30 d in milk) periods. The herds averaged 125 milking cows, and most had 2 defined dry groups (81%). Freestall (FS; 54%) and straw-bedded loose pack (BP; 81%) were the most common housing systems observed in the far-off and close-up periods, respectively. Heifers and cows were housed together in 56, 80, and 59% of the far-off, close-up, and fresh pens, respectively. A large proportion of the far-off (FS: >100% stocking density; BP: <9.3 m2/cow; 41%), close-up, and fresh pens (FS: >80% stocking density; BP: <13.9 m2/cow; 52 and 49%, respectively) were overstocked. Poor water access was observed across all periods (65, 58, and 24% of the far-off, close-up, and fresh, respectively). Only a few farms had proper heat abatement systems in place (absence of properly functioning soakers or fans; <10% in the dry and 15% in the fresh periods). Cows were able to sort their ration in 60% of the dry period pens and 31% of the fresh pens. In 73% of the farms, fresh cow health monitoring protocols were not in place. Colostrum cows and sick cows were housed together in 40% of the farms; 59% separated the newborn from the dam within 2 to 12 h of birth with colostrum harvested immediately thereafter. This work describes prevalent management practices in the dry and fresh periods and highlights areas for potential improvement. Future research should focus on the associations between management choices and health performance of dairy farms.


Asunto(s)
Enfermedades de los Bovinos , Industria Lechera , Animales , Bovinos , Granjas , Femenino , Vivienda para Animales , Leche , Ontario , Estudios Retrospectivos
3.
Nat Commun ; 12(1): 1905, 2021 03 26.
Artículo en Inglés | MEDLINE | ID: mdl-33772024

RESUMEN

Brown and beige adipose tissue are emerging as distinct endocrine organs. These tissues are functionally associated with skeletal muscle, adipose tissue metabolism and systemic energy expenditure, suggesting an interorgan signaling network. Using metabolomics, we identify 3-methyl-2-oxovaleric acid, 5-oxoproline, and ß-hydroxyisobutyric acid as small molecule metabokines synthesized in browning adipocytes and secreted via monocarboxylate transporters. 3-methyl-2-oxovaleric acid, 5-oxoproline and ß-hydroxyisobutyric acid induce a brown adipocyte-specific phenotype in white adipocytes and mitochondrial oxidative energy metabolism in skeletal myocytes both in vitro and in vivo. 3-methyl-2-oxovaleric acid and 5-oxoproline signal through cAMP-PKA-p38 MAPK and ß-hydroxyisobutyric acid via mTOR. In humans, plasma and adipose tissue 3-methyl-2-oxovaleric acid, 5-oxoproline and ß-hydroxyisobutyric acid concentrations correlate with markers of adipose browning and inversely associate with body mass index. These metabolites reduce adiposity, increase energy expenditure and improve glucose and insulin homeostasis in mouse models of obesity and diabetes. Our findings identify beige adipose-brown adipose-muscle physiological metabokine crosstalk.


Asunto(s)
Tejido Adiposo Beige/metabolismo , Tejido Adiposo Pardo/metabolismo , Metabolismo Energético/genética , Homeostasis/genética , Transducción de Señal/genética , Adipocitos Marrones/metabolismo , Adipocitos Blancos/metabolismo , Tejido Adiposo Beige/citología , Tejido Adiposo Pardo/citología , Animales , Línea Celular , Células Cultivadas , Cromatografía Liquida , Cromatografía de Gases y Espectrometría de Masas , Perfilación de la Expresión Génica/métodos , Humanos , Masculino , Espectrometría de Masas , Metabolómica/métodos , Ratones Endogámicos C57BL
4.
PLoS One ; 16(2): e0247300, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33606810

RESUMEN

OBJECTIVE: Gremlin 1 (GREM1) is a secreted BMP2/4 inhibitor which regulates commitment and differentiation of human adipose precursor cells and prevents the browning effect of BMP4. GREM1 is an insulin antagonist and serum levels are high in type 2 diabetes (T2D). We here examined in vivo effects of AAV8 (Adeno-Associated Viral vectors of serotype eight) GREM 1 targeting the liver in mature mice to increase its systemic secretion and also, in a separate study, injected recombinant GREM 1 intraperitoneally. The objective was to characterize systemic effects of GREM 1 on insulin sensitivity, glucose tolerance, body weight, adipose cell browning and other local tissue effects. METHODS: Adult mice were injected with AAV8 vectors expressing GREM1 in the liver or receiving regular intra-peritoneal injections of recombinant GREM1 protein. The mice were fed with a low fat or high fat diet (HFD) and followed over time. RESULTS: Liver-targeted AAV8-GREM1 did not alter body weight, whole-body glucose and insulin tolerance, or adipose tissue gene expression. Although GREM1 protein accumulated in liver cells, GREM1 serum levels were not increased suggesting that it may not have been normally processed for secretion. Hepatic lipid accumulation, inflammation and fibrosis were also not changed. Repeated intraperitoneal rec-GREM1 injections for 5 weeks were also without effects on body weight and insulin sensitivity. UCP1 was slightly but significantly reduced in both white and brown adipose tissue but this was not of sufficient magnitude to alter body weight. We validated that recombinant GREM1 inhibited BMP4-induced pSMAD1/5/9 in murine cells in vitro, but saw no direct inhibitory effect on insulin signalling and pAkt (ser 473 and thr 308) activation. CONCLUSION: GREM1 accumulates intracellularly when overexpressed in the liver cells of mature mice and is apparently not normally processed/secreted. However, also repeated intraperitoneal injections were without effects on body weight and insulin sensitivity and adipose tissue UCP1 levels were only marginally reduced. These results suggest that mature mice do not readily respond to GREMLIN 1 but treatment of murine cells with GREMLIN 1 protein in vitro validated its inhibitory effect on BMP4 signalling while insulin signalling was not altered.


Asunto(s)
Dependovirus/genética , Dieta Alta en Grasa/efectos adversos , Resistencia a la Insulina/genética , Péptidos y Proteínas de Señalización Intercelular/genética , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Hígado/metabolismo , Células 3T3-L1 , Animales , Peso Corporal , Línea Celular , Modelos Animales de Enfermedad , Terapia Genética , Vectores Genéticos/administración & dosificación , Prueba de Tolerancia a la Glucosa , Humanos , Inyecciones Intraperitoneales , Péptidos y Proteínas de Señalización Intercelular/administración & dosificación , Masculino , Ratones , Proteínas Recombinantes/administración & dosificación
5.
J Biol Chem ; 295(44): 15054-15069, 2020 10 30.
Artículo en Inglés | MEDLINE | ID: mdl-32855239

RESUMEN

Strategies to increase energy expenditure are an attractive approach to reduce excess fat storage and body weight to improve metabolic health. In mammals, uncoupling protein-1 (UCP1) in brown and beige adipocytes uncouples fatty acid oxidation from ATP generation in mitochondria and promotes energy dissipation as heat. We set out to identify small molecules that enhance UCP1 levels and activity using a high-throughput screen of nearly 12,000 compounds in mouse brown adipocytes. We identified a family of compounds that increase Ucp1 expression and mitochondrial activity (including un-coupled respiration) in mouse brown adipocytes and human brown and white adipocytes. The mechanism of action may be through compound binding to A kinase anchoring protein (AKAP) 1, modulating its localization to mitochondria and its interaction with protein kinase A (PKA), a known node in the ß-adrenergic signaling pathway. In mice, the hit compound increased body temperature, UCP1 protein levels, and thermogenic gene expression. Some of the compound effects on mitochondrial function were UCP1- or AKAP1-independent, suggesting compound effects on multiple nodes of energy regulation. Overall, our results highlight a role for AKAP1 in thermogenesis, uncoupled respiration, and regulation energy balance.


Asunto(s)
Proteínas de Anclaje a la Quinasa A/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Bibliotecas de Moléculas Pequeñas/farmacología , Termogénesis/efectos de los fármacos , Proteína Desacopladora 1/biosíntesis , Adipocitos Marrones/enzimología , Adipocitos Marrones/metabolismo , Adipocitos Blancos/enzimología , Adipocitos Blancos/metabolismo , Animales , Células Cultivadas , Metabolismo Energético , Activación Enzimática , Perfilación de la Expresión Génica , Ensayos Analíticos de Alto Rendimiento , Humanos , Ratones , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Reproducibilidad de los Resultados , Transducción de Señal
6.
Diabetes ; 69(3): 331-341, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31882566

RESUMEN

The BMP2/4 antagonist and novel adipokine Gremlin 1 is highly expressed in human adipose cells and increased in hypertrophic obesity. As a secreted antagonist, it inhibits the effect of BMP2/4 on adipose precursor cell commitment/differentiation. We examined mRNA levels of Gremlin 1 in key target tissues for insulin and also measured tissue and serum levels in several carefully phenotyped human cohorts. Gremlin 1 expression was high in adipose tissue, higher in visceral than in subcutaneous tissue, increased in obesity, and further increased in type 2 diabetes (T2D). A similar high expression was seen in liver biopsies, but expression was considerably lower in skeletal muscles. Serum levels were increased in obesity but most prominently in T2D. Transcriptional activation in both adipose tissue and liver as well as serum levels were strongly associated with markers of insulin resistance in vivo (euglycemic clamps and HOMA of insulin resistance), and the presence of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH). We also found Gremlin 1 to antagonize insulin signaling and action in human primary adipocytes, skeletal muscle, and liver cells. Thus, Gremlin 1 is a novel secreted insulin antagonist and biomarker as well as a potential therapeutic target in obesity and its complications T2D and NAFLD/NASH.


Asunto(s)
Diabetes Mellitus Tipo 2/genética , Péptidos y Proteínas de Señalización Intercelular/genética , Enfermedad del Hígado Graso no Alcohólico/genética , Obesidad/genética , ARN Mensajero/metabolismo , Adipocitos/efectos de los fármacos , Adipocitos/metabolismo , Adipoquinas/genética , Adipoquinas/metabolismo , Adulto , Anciano , Estudios de Casos y Controles , Diabetes Mellitus Tipo 2/metabolismo , Femenino , Técnica de Clampeo de la Glucosa , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Humanos , Insulina/metabolismo , Antagonistas de Insulina/farmacología , Resistencia a la Insulina/genética , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Péptidos y Proteínas de Señalización Intercelular/farmacología , Grasa Intraabdominal/metabolismo , Hígado/metabolismo , Masculino , Persona de Mediana Edad , Fibras Musculares Esqueléticas/efectos de los fármacos , Fibras Musculares Esqueléticas/metabolismo , Músculo Esquelético/metabolismo , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Obesidad/metabolismo , Cultivo Primario de Células , Grasa Subcutánea/metabolismo
8.
Otolaryngol Head Neck Surg ; 160(5): 839-846, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30832548

RESUMEN

OBJECTIVE: To compare the efficacy of pain control and opioid consumption between patients who receive opioid as primary analgesic therapy and those who receive ibuprofen. STUDY DESIGN: Prospective randomized trial. SETTING: Tertiary care academic hospital. SUBJECT AND METHODS: Adult patients undergoing outpatient otolaryngology surgery were assigned to take hydrocodone/acetaminophen or ibuprofen for postoperative analgesia. Patient-recorded pain scores and analgesic consumption were analyzed. RESULTS: Out of 185 recruits, 108 (58%) completed responses. Fifty-six patients (52%) received opioid medication for primary analgesic treatment versus 52 (48%) who received ibuprofen. There was no difference in reported pain scores between the treatment groups. Those who received ibuprofen as primary therapy reported a significantly lower consumption of opioid medication at 2.04 tablets/pills (95% CI, 0.9-3.1) versus 4.86 (3.6-6.1; P = .001). Based on multivariate analysis, male sex and older age exhibited lower reported pain scores, while older age and use of ibuprofen as primary therapy exhibited lower opioid requirements. CONCLUSION: For postoperative pain management in outpatient otolaryngology procedures, ibuprofen as primary therapy can provide equally effective pain control as compared with hydrocodone/acetaminophen while decreasing overall opioid requirement. Prescription pill counts are further described to help guide physician practices in the era of an opioid epidemic.


Asunto(s)
Acetaminofén/uso terapéutico , Procedimientos Quirúrgicos Ambulatorios/efectos adversos , Analgésicos Opioides/uso terapéutico , Hidrocodona/uso terapéutico , Ibuprofeno/uso terapéutico , Procedimientos Quirúrgicos Otorrinolaringológicos/efectos adversos , Dolor Postoperatorio/tratamiento farmacológico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Combinación de Medicamentos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dimensión del Dolor , Dolor Postoperatorio/diagnóstico , Dolor Postoperatorio/etiología , Estudios Prospectivos , Método Simple Ciego , Adulto Joven
9.
Endocrinology ; 160(1): 205-219, 2019 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-30445425

RESUMEN

The increased hepatic gluconeogenesis in type 2 diabetes mellitus has often been ascribed to increased transcription of phosphoenolpyruvate carboxykinase 1, cystolic form (PEPCK1), although recent evidence has questioned this attribution. To assess the metabolic role of PEPCK1, we treated regular chow fed and high-fat fed (HFF) male Sprague-Dawley rats with a 2'-O-methoxyethyl chimeric antisense oligonucleotide (ASO) against PEPCK1 and compared them with control ASO-treated rats. PEPCK1 ASO effectively decreased PEPCK1 expression in the liver and white adipose tissue. In chow fed rats, PEPCK1 ASO did not alter adiposity, plasma glucose, or insulin. In contrast, PEPCK1 ASO decreased the white adipose tissue mass in HFF rats but without altering basal rates of lipolysis, de novo lipogenesis, or glyceroneogenesis in vivo. Despite the protection from adiposity, hepatic insulin sensitivity was impaired in HFF PEPCK1 ASO-treated rats. PEPCK1 ASO worsened hepatic steatosis, although without additional impairments in hepatic insulin signaling or activation of inflammatory signals in the liver. Instead, the development of hepatic insulin resistance and the decrease in hepatic glycogen synthesis during a hyperglycemic clamp was attributed to a decrease in hepatic glucokinase (GCK) expression and decreased synthesis of glycogen via the direct pathway. The decrease in GCK expression was associated with increased expression of activating transcription factor 3, a negative regulator of GCK transcription. These studies have demonstrated that PEPCK1 is integral to coordinating cellular metabolism in the liver and adipose tissue, although it does not directly effect hepatic glucose production or adipose glyceroneogenesis.


Asunto(s)
Adiposidad , Diabetes Mellitus Tipo 2/enzimología , Péptidos y Proteínas de Señalización Intracelular/genética , Glucógeno Hepático/biosíntesis , Hígado/metabolismo , Oligonucleótidos Antisentido/genética , Fosfoenolpiruvato Carboxiquinasa (GTP)/genética , Tejido Adiposo Blanco/metabolismo , Animales , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/fisiopatología , Dieta Alta en Grasa/efectos adversos , Glucoquinasa/genética , Glucoquinasa/metabolismo , Humanos , Insulina/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Lipogénesis , Masculino , Ratones , Ratones Endogámicos C57BL , Fosfoenolpiruvato Carboxiquinasa (GTP)/metabolismo , Ratas , Ratas Sprague-Dawley
10.
Ear Nose Throat J ; 97(6): 167-172, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30036413

RESUMEN

Despite a lack of robust data regarding their efficacy, oral antibiotics and steroids remain two of the most common treatments for chronic rhinosinusitis without nasal polyps (CRSsNP). We sought to objectively compare the efficacy of antibiotics and steroids, independently and in combination, for the initial treatment of CRSsNP. To that end, we conducted a retrospective chart review of 100 patients-51 men and 49 women, age 20 to 85 years (mean: 50)-who were treated for CRSsNP from January 2010 through January 2015. Of this group, 17 patients were treated with an antibiotic only, 28 with a steroid only, and 55 with both agents. All patients underwent computed tomography (CT) before and after treatment, and we compared the three groups' pre- and post-treatment Lund-Mackay CT scores, symptom scores, and rates of surgery. The average time between the pre- and post-treatment visits was 4.4 weeks. The mean Lund-Mackay CT score for the entire study population was significantly lower after treatment than at baseline (6.3 vs. 9.1; p < 0.001); however, there were no significant differences among the three groups in either pre- or post-treatment scores. Symptom scores were significantly better in the combination therapy group than in the two monotherapy groups (p < 0.001). In all, 40 of the 100 patients underwent surgery; the difference in surgery rates among the three groups was not statistically significant (p = 0.884). Surgery was performed on 9 of the 52 (17.3%) patients who either were followed for at least 1 year or who had had surgery within the first year postoperatively; again, there were no significant differences among the three groups (p = 0.578). We conclude that although the Lund-Mackay CT scores decreased significantly in the antibiotic, steroid, and combination therapy groups, no one regimen was superior to any other for treating CRSsNP in our study.


Asunto(s)
Antibacterianos/administración & dosificación , Rinitis/tratamiento farmacológico , Sinusitis/tratamiento farmacológico , Esteroides/administración & dosificación , Adulto , Enfermedad Crónica , Quimioterapia Combinada , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Rinitis/diagnóstico por imagen , Sinusitis/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Resultado del Tratamiento
11.
Adipocyte ; 6(3): 224-233, 2017 07 03.
Artículo en Inglés | MEDLINE | ID: mdl-28792785

RESUMEN

Over the past 2 decades, the incidence of childhood obesity has risen dramatically. This recent rise in childhood obesity is particularly concerning as adults who were obese during childhood develop type II diabetes that is intractable to current forms of treatment compared with individuals who develop obesity in adulthood. While the mechanisms responsible for the exacerbated diabetic phenotype associated with childhood obesity is not clear, it is well known that childhood is an important time period for the establishment of normal white adipose tissue in humans. This association suggests that exposure to obesogenic stimuli during adipose development may have detrimental effects on adipose function and metabolic homeostasis. In this study, we identify the period of development associated with puberty, postnatal days 18-34, as critical for the establishment of normal adipose mass in mice. Exposure of mice to high fat diet only during this time period results in metabolic dysfunction, increased leptin expression, and increased adipocyte size in adulthood in the absence of sustained increased fat mass or body weight. These findings indicate that exposure to obesogenic stimuli during critical developmental periods have prolonged effects on adipose tissue function that may contribute to the exacerbated metabolic dysfunctions associated with childhood obesity.


Asunto(s)
Tejido Adiposo Blanco/metabolismo , Pubertad/fisiología , Adipocitos/metabolismo , Tejido Adiposo/metabolismo , Tejido Adiposo Blanco/fisiología , Adiposidad/fisiología , Animales , Diabetes Mellitus Tipo 2/etiología , Diabetes Mellitus Tipo 2/metabolismo , Dieta Alta en Grasa/efectos adversos , Femenino , Homeostasis/fisiología , Humanos , Leptina/metabolismo , Masculino , Ratones , Obesidad/metabolismo , Pubertad/metabolismo
12.
Cell Rep ; 20(5): 1038-1049, 2017 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-28768190

RESUMEN

We examined the effect of Bone Morphogenetic Protein 4 (BMP4) on energy expenditure in adult mature mice by targeting the liver with adeno-associated viral (AAV) BMP4 vectors to increase circulating levels. We verified the direct effect of BMP4 in inducing a brown oxidative phenotype in differentiating preadipocytes in vitro. AAV-BMP4-treated mice display marked browning of subcutaneous adipocytes, with increased mitochondria and Uncoupling Protein 1 (UCP1). These mice are protected from obesity on a high-fat diet and have increased whole-body energy expenditure, improved insulin sensitivity, reduced liver fat, and reduced adipose tissue inflammation. On a control diet, they show unchanged body weight but improved insulin sensitivity. In contrast, AAV-BMP4-treated mice showed beiging of BAT with reduced UCP1, increased lipids, and reduced hormone-sensitive lipase (HSL). Thus, BMP4 exerts different effects on WAT and BAT, but the overall effect is to enhance insulin sensitivity and whole-body energy expenditure by browning subcutaneous adipose tissue.


Asunto(s)
Adipocitos Marrones/metabolismo , Proteína Morfogenética Ósea 4/biosíntesis , Dependovirus , Terapia Genética/métodos , Obesidad/prevención & control , Grasa Subcutánea/metabolismo , Animales , Proteína Morfogenética Ósea 4/genética , Metabolismo Energético , Masculino , Ratones , Obesidad/genética , Obesidad/metabolismo , Proteína Desacopladora 1/genética , Proteína Desacopladora 1/metabolismo
13.
Cell Metab ; 24(1): 142-50, 2016 07 12.
Artículo en Inglés | MEDLINE | ID: mdl-27320063

RESUMEN

The sexually dimorphic distribution of adipose tissue influences the development of obesity-associated pathologies. The accumulation of visceral white adipose tissue (VWAT) that occurs in males is detrimental to metabolic health, while accumulation of subcutaneous adipose tissue (SWAT) seen in females may be protective. Here, we show that adipocyte hyperplasia contributes directly to the differential fat distribution between the sexes. In male mice, high-fat diet (HFD) induces adipogenesis specifically in VWAT, while in females HFD induces adipogenesis in both VWAT and SWAT in a sex hormone-dependent manner. We also show that the activation of adipocyte precursors (APs), which drives adipocyte hyperplasia in obesity, is regulated by the adipose depot microenvironment and not by cell-intrinsic mechanisms. These findings indicate that APs are plastic cells, which respond to both local and systemic signals that influence their differentiation potential independent of depot origin. Therefore, depot-specific AP niches coordinate adipose tissue growth and distribution.


Asunto(s)
Adipogénesis , Tejido Adiposo/fisiología , Obesidad/fisiopatología , Adipocitos/metabolismo , Adipocitos/patología , Tejido Adiposo Blanco/crecimiento & desarrollo , Tejido Adiposo Blanco/metabolismo , Animales , Dieta Alta en Grasa , Femenino , Hiperplasia , Masculino , Ratones , Obesidad/patología , Tamaño de los Órganos , Caracteres Sexuales
14.
Adipocyte ; 4(3): 203-11, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26257993

RESUMEN

The production of new adipocytes requires the differentiation of adipocyte precursor (AP) cells residing within the adipose tissue stromal-vascular compartment. The objective was to obtain an immortalized primary adipogenic cell line derived from FACS isolated committed APs using the conditional expression of SV40 T antigen. Adipocyte precursors were isolated from white adipose tissue (WAT) using FACS to remove non-adipogenic cell populations from mice expressing a conditionally regulated SV40 T antigen. APs were maintained by continuous culture and induced to undergo adipogenic differentiation. Adipogenesis, determined by Oil Red O staining, was assessed with each passage and compared to wildtype controls. Adipogenic capability was rapidly lost with increased passage number in committed APs with concurrent reduction in cell proliferation and expression of essential late adipogenic genes, including Pparγ and C/ebpα. Thus, FACS purified committed APs have limited capability to undergo expansion and subsequent adipogenic differentiation in vitro even if they are immortalized with the SV40 T antigen.

15.
Am J Bioeth ; 15(5): 3-17, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25970382

RESUMEN

There is little information about the content of ethics consultations (EC) in pediatrics. We sought to describe the reasons for consultation and ethical principles addressed during EC in pediatrics through retrospective review and directed content analysis of EC records (2000-2011) at St. Jude Children's Research Hospital. Patient-based EC were highly complex and often involved evaluation of parental decision making, particularly consideration of the risks and benefits of a proposed medical intervention, and the physician's fiduciary responsibility to the patient. Nonpatient consultations provided guidance in the development of institutional policies that would broadly affect patients and families. This is one of the few existing reviews of the content of pediatric EC and indicates that the distribution of ethical issues and reasons for moral distress are different than with adults. Pediatric EC often facilitates complex decision making among multiple stakeholders, and further prospective research is needed on the role of ethics consultation in pediatrics.


Asunto(s)
Toma de Decisiones/ética , Consultoría Ética , Pediatría/ética , Centros Médicos Académicos , Adolescente , Adulto , Niño , Preescolar , Comités de Ética en Investigación , Femenino , Hospitales Pediátricos , Humanos , Lactante , Masculino , Obligaciones Morales , Negociación , Cuidados Paliativos/ética , Padres , Autonomía Personal , Estudios Retrospectivos , Medición de Riesgo , Tennessee
16.
J Pediatr Hematol Oncol ; 37(4): 257-63, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25887639

RESUMEN

PURPOSE: Pediatric cancer represents 1% to 4% of all cancers worldwide, with the majority of diagnoses in developing countries where mortality remains much higher than that in high-income countries. We sought to describe differences in ethical decision-making at the end of life among an international sample of pediatric oncologists practicing in countries with a variety of income levels and resource settings. METHODS: Pediatric oncologists subscribing to an educational international oncology Web site were invited to complete a 38-item web-based survey investigating ethical domains related to end-of-life care: level of care, fiduciary responsibility, decision making, and justice. RESULTS: Responses were received from 401 physicians in 83 countries, with most respondents practicing in middle-income or high-income countries. Significant differences in attitudes toward ethical issues existed across the national developmental indices. CONCLUSIONS: Further education on ethical principles is warranted in pediatric oncology, particularly among oncologists practicing in low-income or middle-income countries.


Asunto(s)
Toma de Decisiones/ética , Oncología Médica/ética , Cuidado Terminal/ética , Humanos , Renta , Cuidados para Prolongación de la Vida , Cuidados Paliativos , Justicia Social
17.
Int Forum Allergy Rhinol ; 5(7): 605-9, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25907564

RESUMEN

BACKGROUND: Medical treatment of chronic rhinosinusitis with nasal polyposis (CRSwNP) centers on the administration of steroids. High-dose topical nasal steroids (HDTNS) have shown promising results with less systemic effects than oral steroids. One promising HDTNS is 0.132% dexamethasone nasal spray. We investigated whether intranasal dexamethasone was associated with changes in serum cortisol and/or intraocular pressure (IOP). METHODS: Patients with CRSwNP were treated with dexamethasone sodium phosphate 0.132% nasal spray twice daily. Morning serum cortisol and IOP were checked after at least 6 weeks of therapy. RESULTS: Twenty-eight patients met study criteria. The average serum cortisol level after at least 6 weeks of therapy (average duration of 38.3 weeks) was 9.8 µg/dL (normal range, 4 to 22 µg/dL). Ten patients had suppressed cortisol levels (average, 2.5 µg/dL). Ten patients underwent IOP measurements and none revealed ocular hypertension on tonometry. CONCLUSION: High-dose dexamethasone nasal spray given for a period of at least 6 weeks does appear to have the potential to cause a decrease in serum cortisol levels; however, future studies with greater power are necessary to support this claim. Additionally, similar administration of high-dose dexamethasone nasal spray did not reveal IOP diagnostic of ocular hypertension on single-measurement tonometry readings.


Asunto(s)
Dexametasona/uso terapéutico , Glucocorticoides/uso terapéutico , Hidrocortisona/sangre , Presión Intraocular/efectos de los fármacos , Pólipos Nasales/tratamiento farmacológico , Rociadores Nasales , Rinitis/tratamiento farmacológico , Sinusitis/tratamiento farmacológico , Administración Intranasal , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Enfermedad Crónica , Dexametasona/administración & dosificación , Femenino , Glucocorticoides/administración & dosificación , Humanos , Masculino , Persona de Mediana Edad , Pólipos Nasales/sangre , Estudios Retrospectivos , Rinitis/sangre , Sinusitis/sangre , Tonometría Ocular , Adulto Joven
18.
Nat Cell Biol ; 17(4): 376-85, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25730471

RESUMEN

Excessive accumulation of white adipose tissue (WAT) is the defining characteristic of obesity. WAT mass is composed primarily of mature adipocytes, which are generated through the proliferation and differentiation of adipocyte precursors (APs). Although the production of new adipocytes contributes to WAT growth in obesity, little is known about the cellular and molecular mechanisms underlying adipogenesis in vivo. Here, we show that high-fat diet feeding in mice rapidly and transiently induces proliferation of APs within WAT to produce new adipocytes. Importantly, the activation of adipogenesis is specific to the perigonadal visceral depot in male mice, consistent with the patterns of obesogenic WAT growth observed in humans. Furthermore, we find that in multiple models of obesity, the activation of APs is dependent on the phosphoinositide 3-kinase (PI3K)-AKT2 pathway; however, the development of WAT does not require AKT2. These data indicate that developmental and obesogenic adipogenesis are regulated through distinct molecular mechanisms.


Asunto(s)
Adipocitos Blancos/citología , Adipogénesis/fisiología , Obesidad/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Adipocitos Blancos/metabolismo , Adipogénesis/efectos de los fármacos , Adipogénesis/genética , Tejido Adiposo Blanco , Androstadienos/farmacología , Animales , Proliferación Celular/efectos de los fármacos , Proliferación Celular/genética , Dieta Alta en Grasa , Ingestión de Alimentos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Inhibidores de las Quinasa Fosfoinosítidos-3 , Proteínas Proto-Oncogénicas c-akt/genética , Distribución Aleatoria , Tamoxifeno/farmacología , Wortmanina
20.
J Adolesc Young Adult Oncol ; 3(4): 160-175, 2014 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-25538861

RESUMEN

The usual age range of acute lymphoblastic malignancies (acute lymphoblastic leukemia and advanced-stage lymphoblastic lymphoma) includes teenagers and young adults (<22 years of age) and coincides with the age of fertility. Concurrence of acute lymphoblastic malignancy with pregnancy is therefore most likely to happen during the younger childbearing ages. However, the therapeutic challenges posed by the dual diagnosis of lymphoblastic malignancy and pregnancy have not specifically been studied in the context of age, and management guidelines for pregnant young patients are lacking. Inconsistency in defining the legal decision-making rights of pregnant teenaged patients adds a further level of complexity in this age group. Management of this challenging combination in the young patient therefore entails unique ethical considerations. Here we present two illustrative cases of teenage pregnancy complicated by acute lymphoblastic malignancy, review the available literature, and offer suggestions for the therapeutic management of such cases in adolescent and young adult patients. Importantly, practical management recommendations are provided in the context of clinical ethics principles that are universally applicable, including in developing countries, where the highest incidence of adolescent pregnancies has been documented.

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