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1.
Diabetes Ther ; 15(4): 855-867, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38427164

RESUMEN

INTRODUCTION: Optimal glycemic management after diabetes onset remains a challenge in Hispanic/Latino adults with type 2 diabetes (T2D), often resulting in poor health outcomes and higher rates of diabetes-related complications. The aim of this study was to examine and compare demographic and clinical characteristics, glycemic outcomes, health care resource utilization (HCRU), and costs among injection-naïve Hispanic/Latino adults with T2D initiating dulaglutide or basal insulin. METHODS: This retrospective, observational study used administrative claims data from the Optum Research Database. Hispanic/Latino adults with T2D were assigned to dulaglutide or basal insulin cohorts on the basis of pharmacy claims and were propensity-score matched on demographic and baseline characteristics. Measures of glycemic management included 12 month follow-up glycated hemoglobin (HbA1c) and change in HbA1c from baseline. Follow-up all-cause and diabetes-related HCRU and costs, including costs per 1% change in HbA1c, were compared between cohorts. RESULTS: The final propensity-score matched sample included 2872 patients: 1436 patients in each cohort. Mean (SD) reduction in HbA1c from baseline to 12 month follow-up was greater in the dulaglutide cohort compared with the basal insulin cohort [-1.40% (1.88) versus -0.92% (2.07); p < 0.001]. The dulaglutide cohort had significantly lower proportions of patients with ≥ 1 all-cause and diabetes-related outpatient visits, emergency room visits, and inpatient stays compared with the basal insulin cohort (p < 0.05). The dulaglutide cohort had significantly lower all-cause total costs per 1% HbA1c reduction than the basal insulin cohort ($13,768 versus $19,128; p < 0.001). Diabetes-related costs per 1% reduction were numerically lower for the dulaglutide cohort, but the difference was not statistically significant ($9737 versus $11,403; p = 0.081). CONCLUSIONS: Dulaglutide demonstrated better glycemic outcomes and lower all-cause costs per 1% HbA1c reduction among Hispanic/Latino adults compared with those initiating basal insulin. Our real-world findings in the Hispanic/Latino population were consistent with results obtained from the overall population and confirm the glycemic benefits of dulaglutide observed in clinical settings.

2.
J Clin Endocrinol Metab ; 109(7): 1745-1753, 2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-38252888

RESUMEN

CONTEXT: In previous SURPASS studies tirzepatide reduced hemoglobin glycated A1c (HbA1c) and body weight and improved markers of insulin sensitivity and ß-cell function to a greater extent than comparators. OBJECTIVE: Explore changes in biomarkers of ß-cell function and insulin sensitivity and in efficacy profiles in baseline biomarker quartile analyses with tirzepatide compared to semaglutide. DESIGN: Post hoc analysis of SURPASS-2 phase 3 trial (participants randomly assigned to receive weekly subcutaneous tirzepatide or semaglutide for 40 weeks). SETTING: Post hoc analysis of 128 sites in 8 countries. PARTICIPANTS: A total of 1879 participants with type 2 diabetes. INTERVENTIONS: Once-weekly tirzepatide (5, 10, 15 mg) or semaglutide 1 mg. MAIN OUTCOMES MEASURES: Change in homeostatic model assessment indices for pancreatic ß-cell function (HOMA2-B) and for insulin resistance (HOMA2-IR), fasting glucagon, fasting C-peptide, and fasting insulin. RESULTS: At week 40, a greater increase in HOMA2-B was seen with tirzepatide (5, 10, 15 mg) doses (96.9-120.4%) than with semaglutide 1 mg (84.0%) (P < .05). There was a greater reduction in HOMA2-IR with all doses of tirzepatide (15.5%-24.0%) than with semaglutide 1 mg (5.1%) (P < .05). Tirzepatide 10 and 15 mg resulted in a significant reduction in both fasting C-peptide (5.2%-6.0%) and fasting glucagon (53.0%-55.3%) compared with an increase of C-peptide (3.3%) and a reduction of glucagon (47.7%) with semaglutide 1 mg (P < .05). HbA1c and body weight reductions were greater with all tirzepatide doses than semaglutide within each HOMA2-B and HOMA2-IR baseline quartile. CONCLUSION: In this post hoc analysis, improvements in HbA1c and weight loss were consistent and significantly higher with tirzepatide, regardless of baseline ß-cell function and insulin resistance, compared with semaglutide.


Asunto(s)
Biomarcadores , Diabetes Mellitus Tipo 2 , Péptidos Similares al Glucagón , Hipoglucemiantes , Resistencia a la Insulina , Humanos , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/metabolismo , Masculino , Femenino , Persona de Mediana Edad , Péptidos Similares al Glucagón/administración & dosificación , Péptidos Similares al Glucagón/farmacología , Hipoglucemiantes/administración & dosificación , Hipoglucemiantes/farmacología , Hipoglucemiantes/uso terapéutico , Biomarcadores/sangre , Hemoglobina Glucada/análisis , Células Secretoras de Insulina/efectos de los fármacos , Células Secretoras de Insulina/metabolismo , Glucemia/efectos de los fármacos , Glucemia/metabolismo , Anciano , Adulto , Método Doble Ciego , Insulina/sangre , Insulina/metabolismo , Islotes Pancreáticos/efectos de los fármacos , Islotes Pancreáticos/metabolismo , Resultado del Tratamiento , Receptor del Péptido 2 Similar al Glucagón , Polipéptido Inhibidor Gástrico
3.
J Clin Endocrinol Metab ; 109(2): 557-568, 2024 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-37602701

RESUMEN

CONTEXT: Efficacy and safety of tirzepatide, a once-weekly glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 receptor agonist, have been studied in patients with type 2 diabetes in the global phase 3 SURPASS program. OBJECTIVE: This work aimed to assess the efficacy and safety of tirzepatide in Hispanic/Latino and non-Hispanic/Latino patients in SURPASS-1 to -4 clinical trials. METHODS: A total of 5679 patients were included, 2895 of self-reported Hispanic/Latino ethnicity, in this exploratory analysis of SURPASS-1 to -4 trial data. Interventions included tirzepatide 5, 10, or 15 mg, placebo, or active comparator (semaglutide 1 mg, insulin degludec, and insulin glargine). Change in glycated hemoglobin A1c (HbA1c) and body weight from baseline to week 40 (SURPASS-1 and -2) and to week 52 (SURPASS-3 and -4), and other efficacy and safety outcomes were evaluated within Hispanic/Latino and non-Hispanic/Latino subgroups. RESULTS: Among Hispanic/Latino and non-Hispanic/Latino patients treated with tirzepatide, respectively, HbA1c decreased significantly from baseline, ranging from 1.9% to 2.7% and 1.7% to 2.5%, and body weight decreased significantly from baseline, ranging from 5.3 kg to 12.4 and 6.5 kg to 17.1 kg (both P < .05) vs comparators across all trials. Subgroup trends were consistent with the overall trial populations. Treatment-emergent adverse events were reported in similar proportions across the subgroups and were primarily gastrointestinal disorders. The incidence of hypoglycemia was low. CONCLUSION: Tirzepatide significatively reduced HbA1c and body weight in Hispanic/Latino and non-Hispanic/Latino patients. Tirzepatide was generally well tolerated in both subgroups. Efficacy and safety trends were comparable between subgroups and within the overall trial populations.


Asunto(s)
Diabetes Mellitus Tipo 2 , Receptor del Péptido 1 Similar al Glucagón , Hipoglucemiantes , Incretinas , Humanos , Peso Corporal , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Polipéptido Inhibidor Gástrico , Receptor del Péptido 1 Similar al Glucagón/agonistas , Receptor del Péptido 2 Similar al Glucagón , Hemoglobina Glucada , Hispánicos o Latinos , Hipoglucemiantes/uso terapéutico , Incretinas/uso terapéutico
4.
Scand Cardiovasc J ; 57(1): 2166101, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-36723445

RESUMEN

Objectives. To assess whether the use of cardioprotective therapies for type 2 diabetes varies by gender and whether the risk of cardiovascular events is higher in women versus men in the REWIND trial, including an international type 2 diabetes patient population with a wide range of baseline risk. Design. Gender differences in baseline characteristics, cardioprotective therapy, and the achieved clinical targets at baseline and two years were analyzed. Hazards for cardiovascular outcomes (fatal/nonfatal stroke, fatal/nonfatal myocardial infarction, cardiovascular death, all-cause mortality, and heart failure hospitalization), in women versus men were analyzed using two Cox proportional hazard models, adjusted for randomized treatment and key baseline characteristics respectively. Time-to-event analyses were performed in subgroups with or without history of cardiovascular disease using Cox proportional hazards models that included gender, subgroup, randomized treatment, and gender-by-subgroup interactions. Results. Of 9901 participants, 46.3% were women. Significantly fewer women than men had a cardiovascular disease history. Although most women met treatment targets for blood pressure (96.7%) and lipids (72.8%), fewer women than men met the target for cardioprotective therapies at baseline and after two years, particularly those with prior cardiovascular disease, who used less renin-angiotensin-aldosterone system inhibitors, statins, and aspirin than men. Despite these differences, women had lower hazards than men for all outcomes except stroke. No significant gender and cardiovascular disease history interactions were identified for cardiovascular outcomes. Conclusions. In REWIND, most women met clinically relevant treatment targets, but in lower proportions than men. Women had a lower risk for all cardiovascular outcomes except stroke. Clinical trials.gov registration number: NCT01394952.


Asunto(s)
Enfermedades Cardiovasculares , Diabetes Mellitus Tipo 2 , Accidente Cerebrovascular , Masculino , Humanos , Femenino , Enfermedades Cardiovasculares/diagnóstico , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/terapia , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/epidemiología , Factores de Riesgo , Factores Sexuales , Factores de Riesgo de Enfermedad Cardiaca , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/epidemiología
5.
Diabetes Care ; 45(3): 547-554, 2022 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-35043140

RESUMEN

OBJECTIVE: To evaluate participant characteristics and long-term changes in glycated hemoglobin (HbA1c) levels in patients treated with dulaglutide 1.5 mg in a post hoc analysis of the Researching cardiovascular Events with a Weekly INcretin in Diabetes (REWIND) trial. RESEARCH DESIGN AND METHODS: Change from baseline in HbA1c was assessed during and up to 72 months of treatment before and after adjustment for duration of diabetes, prior microvascular disease (nephropathy or retinopathy), and BMI. Slope analyses were used to assess the change in HbA1c during 0-12 months and 12-72 months of therapy. RESULTS: HbA1c was significantly reduced in patients treated with dulaglutide compared with placebo during 72 months of treatment (least-squares mean difference = -0.61%, P < 0.001), regardless of diabetes duration, prior microvascular disease, and BMI (all interaction P > 0.07). Significant reductions were apparent at all time points and were independent of these baseline characteristics. Slope analyses revealed that the dulaglutide group experienced a higher rate of HbA1c reduction compared with the placebo group from 0 to 12 months before and after adjustment. The dulaglutide group also experienced a higher rate of HbA1c increase from 12 to 72 months compared with the placebo group that became nonsignificant after adjustment for diabetes duration, prior microvascular disease, and BMI combined. Despite the greater rate of HbA1c increase in the dulaglutide group during this period, mean HbA1c values remained below baseline in the dulaglutide group and below mean HbA1c values in the placebo group. CONCLUSIONS: Dulaglutide 1.5-mg treatment was statistically associated with a long-lasting decrease in HbA1c over 72 months, irrespective of baseline duration of diabetes, microvascular disease, and BMI.


Asunto(s)
Diabetes Mellitus Tipo 2 , Péptidos Similares al Glucagón/uso terapéutico , Hipoglucemiantes , Fragmentos Fc de Inmunoglobulinas/uso terapéutico , Índice de Masa Corporal , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Péptidos Similares al Glucagón/análogos & derivados , Hemoglobina Glucada/análisis , Humanos , Hipoglucemiantes/uso terapéutico , Proteínas Recombinantes de Fusión/uso terapéutico , Resultado del Tratamiento
6.
Diabetes Obes Metab ; 22(12): 2209-2226, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32744372

RESUMEN

Despite treatment advances leading to improved outcomes over the past 2 decades, cardiovascular (CV) disease (CVD) remains the leading cause of morbidity and mortality in people with diabetes. People with type 2 diabetes (T2D) have a 2- to 4-fold increased risk of CVD and CV death. Individuals with T2D have not seen the same improvements in CV morbidity and mortality as those without T2D. Given this, it is important to understand the CV impact of drugs used to treat T2D. In patients with T2D, glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have shown a reduction in HbA1c and body weight regardless of their differences in chemical structure and pharmacokinetic variables. Glycaemic efficacy, accompanied by the potential for weight reduction and a low risk of hypoglycaemia, has moved GLP-1 RAs to the first treatment of choice following metformin monotherapy in the latest American Diabetes Association treatment guidelines. Additionally, all GLP-1 RAs have shown CV safety and several have proven CV benefit. GLP-1 RAs have been evaluated in cardiovascular outcomes trials (CVOTs) of varying sizes, designs and patient populations with differing reported effects on CV outcomes. The purpose of this article is to review the completed GLP-1 RA CVOTs with special attention to how their design, size, patient populations and conduct may influence the interpretation of results.


Asunto(s)
Enfermedades Cardiovasculares , Diabetes Mellitus Tipo 2 , Preparaciones Farmacéuticas , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/prevención & control , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/epidemiología , Receptor del Péptido 1 Similar al Glucagón/agonistas , Humanos , Hipoglucemiantes/uso terapéutico , Factores de Riesgo
7.
Surg Obes Relat Dis ; 16(10): 1514-1520, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32665112

RESUMEN

BACKGROUND: While patients are becoming older and the prevalence of obesity increases worldwide, literature on the impact of age on outcomes after laparoscopic Roux-en-Y gastric bypass (LRYGB) is scarce. The balance between surgical risks and clinical benefits of LRYGB are unclear in relation to age. OBJECTIVES: To evaluate the impact of age on the risk of postoperative complications, postoperative weight loss, and remission of co-morbidities for patients who underwent LRYGB. SETTING: A high-volume center for bariatric surgery. METHODS: A retrospective analysis of 582 patients who underwent LRYGB was performed. Linear logistic regression analyses were performed to evaluate the potential impact of age on the postoperative percentage of total weight loss (%TWL). Multivariable binary logistic regression analyses were performed to evaluate whether age was independently associated with the risk of postoperative complications and likelihood of remission of co-morbidities (hypertension, diabetes, and dyslipidemia). In addition, these outcomes were descriptively analyzed for the following 3 age groups: the young (18-39 yr), the middle aged (40-59 yr), and the elderly (≥60 yr). RESULTS: Patients with hypertension were more prone to developing postoperative complications (odds ratio 2.435, 95% confidence interval: 1.241-4.777) and no other factors were found to be associated with the risk of postoperative complications. Older age was significantly associated with lower %TWL at a postoperative follow-up of 6 (ß = -.117, P = .004), 12 (ß = -.177, P < .001), and 36 months (ß = -.169, P = .001), but not at 60 months (ß = -.097, P = .161). Nonetheless, a %TWL of 30% was observed in patients who were >60 years at the time of surgery. Age was not associated with the likelihood of co-morbidity resolution after LRYGB. The remission of hypertension was less likely in patients with co-existence of diabetes (odds ratio .334, 95% confidence interval: .136-.821) and in patients with a longer length of postoperative follow-up (odds ratio .982, 95% confidence interval: .966-.998). CONCLUSIONS: Although older age seems to be associated with lower postoperative %TWL, elderly patients can still achieve a %TWL of 30% after LRYGB. In this study, age was not found to be an independent predictor of postoperative complications nor the likelihood of co-morbidity resolution. Therefore, older age alone should not be an absolute contraindication for LRYGB.


Asunto(s)
Derivación Gástrica , Laparoscopía , Obesidad Mórbida , Anciano , Humanos , Persona de Mediana Edad , Obesidad Mórbida/cirugía , Complicaciones Posoperatorias/epidemiología , Estudios Retrospectivos , Resultado del Tratamiento , Pérdida de Peso
8.
Rev. argent. cir ; 112(3): 293-302, jun. 2020. graf
Artículo en Español | LILACS | ID: biblio-1279742

RESUMEN

RESUMEN Introducción: los octogenarios son un grupo demográficamente en crecimiento. Este aumento en la esperanza de vida pone al cirujano frecuentemente frente a pacientes de edad avanzada con una hernia inguinal. Objetivo: analizar la aplicabilidad, seguridad y eficacia del tratamiento quirúrgico ambulatorio de la hernia inguinal en pacientes mayores de 80 años. Material y método: estudio comparativo, de cohorte retrospectiva. Se analizaron todas las hernio plastias inguinales por vía abierta con técnica de Lichtenstein realizadas entre 2008 y 2017, con al menos un mes de seguimiento. Estos pacientes fueron comparados de forma retrospectiva con todos aquellos de iguales características de entre 50 y 79 años tratados durante el mismo período de tiempo. Resultados: entre 2008 y 2017, 491 pacientes ingresaron en el Programa de Cirugía Mayor Ambulato ria y fueron sometidos a reparación de una hernia inguinal con técnica de Lichtenstein. De estos, 133 pacientes (27, 1%) eran mayores de 80 años, y 358 pacientes (72,9%) de entre 50 y 79 años. La mor bilidad posoperatoria global de la serie fue del 9,75% (13,5% para mayores de 80 años y 8,4% para el grupo control, p = NS). Tampoco hubo diferencia estadísticamente significativa en admisión temprana (3,8% vs. 2,8% del grupo control, p = NS). Conclusión: la cirugía ambulatoria en la hernioplastia por vía abierta, en pacientes mayores de 80 años, fue aplicada de forma segura y eficaz.


ABSTRACT Background: Octogenarians are a demographically growing group. This increase in life expectancy of ten makes surgeons face older patients with inguinal hernia. Objective: The aim of this study was to analyze the applicability, safety and efficacy of ambulatory inguinal hernia in patients > 80 years, Material and methods: We conducted a retrospective and observational cohort study. Data from all the open inguinal hernia repair procedures performed using the Lichtenstein technique between January 2008 and December 2017 and followed-up after one month were analyzed. These patients were retrospectively compared with similar patients aged 50-79 years who were treated during the same period. Results: Between 2008 and 2017, 491 patients admitted in the Major Ambulatory Surgery program underwent inguinal hernia repair using the Lichtenstein technique. 133 (27.1%) were > 80 years and 358 (72.9%) were between 50 and 79 years. Overall postoperative morbidity was 9.75% (13.5% in > 80 years and 8.4% in the control group; p = NS). There were no significant differences in unanticipated mortality (3.8% vs. 2.8%un the control group, p = NS). Conclusion: Ambulatory surgery for open inguinal hernia repair in patients > 80 years is a safe and effective strategy.


Asunto(s)
Humanos , Masculino , Femenino , Persona de Mediana Edad , Anciano , Anciano de 80 o más Años , Eficacia , Hernia Inguinal/cirugía , Argentina , Seguridad , Anciano , Estudios Retrospectivos , Estudios de Cohortes , Herniorrafia/métodos , Procedimientos Quirúrgicos Ambulatorios/métodos
9.
Dev Dyn ; 248(11): 1059-1069, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31454122

RESUMEN

lncRNAs, genes transcribed but not translated, longer than 200 nucleotides, are classified as a separate class of nonprotein coding genes. Since their discovery, largely from RNAseq data, a number of pioneer studies have begun to unravel its myriad functions, centered on gene expression regulation, suggesting developmental and evolutionary conservation. Since they do not code for proteins and have no open reading frames, their functional constraints likely differ from that of protein coding genes, or of genes where the majority of the nucleotide sequence is required for function, like tRNAs. This has complicated assessment of both developmental and evolutionary conservation, and the identification of homologs in different species. Here we argue that other characteristics: general synteny and particular chromosomal placement regardless of sequence, sequence micro-motifs, and secondary structure allow for "homologs" to be identified and compared, confirming developmental and evolutionary conservation of lncRNAs. We conclude exemplifying a case in point: that of the evolutionarily conserved lncRNA acal, characterized and required for embryogenesis in Drosophila.


Asunto(s)
Embrión no Mamífero/embriología , Desarrollo Embrionario/fisiología , Evolución Molecular , Regulación del Desarrollo de la Expresión Génica/fisiología , ARN Largo no Codificante , Animales , Drosophila , ARN Largo no Codificante/biosíntesis , ARN Largo no Codificante/genética
10.
PeerJ ; 6: e5042, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29942698

RESUMEN

Morphogenetic movements during embryogenesis require dynamic changes in epithelial cell polarity and cytoskeletal reorganization. Such changes involve, among others, rearrangements of cell-cell contacts and protein traffic. In Drosophila melanogaster, neuroblast delamination during early neurogenesis is a well-characterized process requiring a polarized neuroepithelium, regulated by the Notch signaling pathway. Maintenance of epithelial cell polarity ensues proper Notch pathway activation during neurogenesis. We characterize here aaquetzalli (aqz), a gene whose mutations affect cell polarity and nervous system specification. The aqz locus encodes a protein that harbors a domain with significant homology to a proline-rich conserved domain of nuclear receptor co-activators. aqz expression occurs at all stages of the fly life cycle, and is dynamic. aqz mutants are lethal, showing a disruption of cell polarity during embryonic ventral neuroepithelium differentiation resulting in loss of epithelial integrity and mislocalization of membrane proteins (shown by mislocalization of Crumbs, DE-Cadherin, and Delta). As a consequence, aqz mutant embryos with compromised apical-basal cell polarity develop spotty changes of neuronal and epithelial numbers of cells.

11.
Dev Cell ; 36(3): 290-302, 2016 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-26859353

RESUMEN

Chromosomal instability (CIN) is thought to be a source of mutability in cancer. However, CIN often results in aneuploidy, which compromises cell fitness. Here, we used the dosage compensation mechanism (DCM) of Drosophila to demonstrate that chromosome-wide gene dosage imbalance contributes to the deleterious effects of CIN-induced aneuploidy and its pro-tumorigenic action. We present evidence that resetting of the DCM counterbalances the damaging effects caused by CIN-induced changes in X chromosome number. Importantly, interfering with the DCM suffices to mimic the cellular effects of aneuploidy in terms of reactive oxygen species (ROS) production, JNK-dependent cell death, and tumorigenesis upon apoptosis inhibition. We unveil a role of ROS in JNK activation and a variety of cellular and tissue-wide mechanisms that buffer the deleterious effects of CIN, including DNA-damage repair, activation of the p38 pathway, and cytokine induction to promote compensatory proliferation. Our data reveal the existence of robust compensatory mechanisms that counteract CIN-induced cell death and tumorigenesis.


Asunto(s)
Transformación Celular Neoplásica/genética , Inestabilidad Cromosómica/genética , Aneuploidia , Animales , Apoptosis/genética , Reparación del ADN/genética , Drosophila melanogaster , Dosificación de Gen/genética , Especies Reactivas de Oxígeno/metabolismo
12.
PLoS One ; 6(11): e28067, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-22132213

RESUMEN

Coordination between growth and patterning/differentiation is critical if appropriate final organ structure and size is to be achieved. Understanding how these two processes are regulated is therefore a fundamental and as yet incompletely answered question. Here we show through genetic analysis that the phospholipase C-γ (PLC-γ) encoded by small wing (sl) acts as such a link between growth and patterning/differentiation by modulating some MAPK outputs once activated by the insulin pathway; particularly, sl promotes growth and suppresses ectopic differentiation in the developing eye and wing, allowing cells to attain a normal size and differentiate properly. sl mutants have previously been shown to have a combination of both growth and patterning/differentiation phenotypes: small wings, ectopic wing veins, and extra R7 photoreceptor cells. We show here that PLC-γ activated by the insulin pathway participates broadly and positively during cell growth modulating EGF pathway activity, whereas in cell differentiation PLC-γ activated by the insulin receptor negatively regulates the EGF pathway. These roles require different SH2 domains of PLC-γ, and act via classic PLC-γ signaling and EGF ligand processing. By means of PLC-γ, the insulin receptor therefore modulates differentiation as well as growth. Overall, our results provide evidence that PLC-γ acts during development at a time when growth ends and differentiation begins, and is important for proper coordination of these two processes.


Asunto(s)
Diferenciación Celular , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/citología , Drosophila melanogaster/crecimiento & desarrollo , Fosfolipasa C gamma/metabolismo , Receptor de Insulina/metabolismo , Transducción de Señal , Animales , Proteínas de Drosophila/química , Drosophila melanogaster/enzimología , Drosophila melanogaster/ultraestructura , Ojo/anatomía & histología , Ojo/citología , Ojo/ultraestructura , Femenino , Dosificación de Gen/genética , Genes de Insecto/genética , Sistema de Señalización de MAP Quinasas/genética , Modelos Biológicos , Mutación/genética , Tamaño de los Órganos , Fenotipo , Fosfolipasa C gamma/química , Células Fotorreceptoras de Invertebrados/metabolismo , Estructura Terciaria de Proteína , Transducción de Señal/genética , Alas de Animales/citología , Alas de Animales/enzimología , Alas de Animales/crecimiento & desarrollo
13.
Diabetes ; 60(5): 1632-6, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21464442

RESUMEN

OBJECTIVE: Type 2 diabetes is the most common form of diabetes worldwide. Some of its complications, such as retinopathy and neuropathy, are long-term and protracted, with an unclear etiology. Given this problem, genetic model systems, such as in flies where type 2 diabetes can be modeled and studied, offer distinct advantages. RESEARCH DESIGN AND METHODS: We used individual flies in experiments: control and mutant individuals with partial loss-of-function insulin pathway genes. We measured wing size and tested body weight for growth phenotypes, the latter by means of a microbalance. We studied total lipid and carbohydrate content, lipids by a reaction in single fly homogenates with vanillin-phosphoric acid, and carbohydrates with an anthrone-sulfuric acid reaction. Cholinesterase activity was measured using the Ellman method in head homogenates from pooled fly heads, and electroretinograms with glass capillary microelectrodes to assess performance of central brain activity and retinal function. RESULTS: Flies with partial loss-of-function of insulin pathway genes have significantly reduced body weight, higher total lipid content, and sometimes elevated carbohydrate levels. Brain function is impaired, as is retinal function, but no clear correlation can be drawn from nervous system function and metabolic state. CONCLUSIONS: These studies show that flies can be models of type 2 diabetes. They weigh less but have significant lipid gains (obese); some also have carbohydrate gains and compromised brain and retinal functions. This is significant because flies have an open circulatory system without microvasculature and can be studied without the complications of vascular defects.


Asunto(s)
Insulina/farmacología , Animales , Peso Corporal/genética , Peso Corporal/fisiología , Encéfalo , Drosophila , Electrorretinografía , Metabolismo de los Lípidos/efectos de los fármacos , Metabolismo de los Lípidos/genética , Mutación , Receptor de Insulina/genética , Receptor de Insulina/metabolismo , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genética
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