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The AWARD-11 trial demonstrated the safety and efficacy of dulaglutide 3.0 and 4.5 mg compared to dulaglutide 1.5 mg in patients with type 2 diabetes inadequately controlled with metformin. This post hoc analysis examined the change from baseline in glycated haemoglobin (HbA1c) and proportions of patients achieving HbA1c <7% at weeks 36 and 52 with dulaglutide 1.5 mg, 3.0 mg or 4.5 mg across clinically relevant baseline HbA1c subgroups (<8%; 8.0% to < 9.0%; 9.0% to < 10%; and ≥ 10%). Mean reductions in HbA1c were observed across all baseline HbA1c subgroups at 36 weeks (range of HbA1c change: 1.5 mg: -1.0% to -2.2%; 3.0 mg: -1.2% to -2.5%; and 4.5 mg: -1.2% to -3.2%). More patients randomized to 3.0 mg or 4.5 mg (vs. 1.5 mg) achieved HbA1c <7% at 36 weeks regardless of baseline HbA1c; the difference in proportions was greater at higher baseline HbA1c (P-interaction = 0.096). Similar patterns in glycaemic improvement and proportions achieving HbA1c <7% were observed at 52 weeks. Hypoglycaemia and gastrointestinal adverse events were similar among the HbA1c subgroups. Glycaemic control was improved with dulaglutide dose escalation from 1.5 mg to 3.0 mg or 4.5 mg across baseline HbA1c subgroups (<8%; 8.0% to < 9.0%; 9.0% to < 10%; and ≥ 10%).
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Diabetes Mellitus Tipo 2 , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Péptidos Similares al Glucagón/efectos adversos , Péptidos Similares al Glucagón/análogos & derivados , Hemoglobina Glucada/análisis , Humanos , Hipoglucemiantes/efectos adversos , Fragmentos Fc de Inmunoglobulinas/efectos adversos , Proteínas Recombinantes de Fusión , Resultado del TratamientoRESUMEN
AIM: To evaluate the impact of dulaglutide 3.0 and 4.5 mg versus 1.5 mg on body weight in patients with type 2 diabetes (T2D) based on exploratory analyses of the AWARD-11 trial. MATERIALS AND METHODS: Patients were randomized to once-weekly dulaglutide 1.5 (n = 612), 3.0 (n = 616) or 4.5 mg (n = 614) for 52 weeks. The primary objective was superiority of dulaglutide 3.0 and/or 4.5 mg over 1.5 mg in HbA1c reduction at 36 weeks. Secondary and exploratory assessments included weight reduction in the overall trial population and baseline body mass index (BMI) and HbA1c subgroups. RESULTS: At baseline, patients had a mean age of 57.1 years, HbA1c 8.6% (70 mmol/mol), weight 95.7 kg and BMI 34.2 kg/m2 . At 36 weeks, dulaglutide 3.0 and 4.5 mg were superior to 1.5 mg for weight change from baseline (1.5 mg, -3.1 kg; 3.0 mg, -4.0 kg [P = .001]; 4.5 mg, -4.7 kg [P < .001]). Higher dulaglutide doses were associated with numerically greater weight reduction compared with 1.5 mg in each baseline BMI and HbA1c subgroup. Absolute weight reduction increased with increasing BMI category, but percentage weight loss was similar between subgroups. Weight reductions with dulaglutide were greater in patients with lower versus higher baseline HbA1c. CONCLUSIONS: In patients with T2D, inadequately controlled by metformin, incremental weight loss was observed with dulaglutide 1.5, 3.0 and 4.5 mg doses regardless of baseline BMI or HbA1c. Although absolute weight loss was numerically greater in patients with higher baseline BMI, percentage of weight loss was similar between BMI subgroups.
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Diabetes Mellitus Tipo 2 , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Péptidos Similares al Glucagón/efectos adversos , Péptidos Similares al Glucagón/análogos & derivados , Hemoglobina Glucada/análisis , Humanos , Hipoglucemiantes/efectos adversos , Fragmentos Fc de Inmunoglobulinas/efectos adversos , Persona de Mediana Edad , Proteínas Recombinantes de FusiónRESUMEN
This white paper provides a summary of the presentations and discussions from a think tank on "Enabling Social Listening for Cardiac Safety Monitoring" trials that was cosponsored by the Drug Information Association and the Cardiac Safety Research Consortium, and held at the White Oak headquarters of the US Food and Drug Administration on June 3, 2016. The meeting's goals were to explore current methods of collecting and evaluating social listening data and to consider their applicability to cardiac safety surveillance. Social listening is defined as the act of monitoring public postings on the Internet. It has several theoretical advantages for drug and device safety. First, these include the ability to detect adverse events that are "missed" by traditional sources and the ability to detect adverse events sooner than would be allowed by traditional sources, both by affording near-real-time access to data from culturally and geographically diverse sources. Social listening can also potentially introduce a novel patient voice into the conversation about drug safety, which could uniquely augment understanding of real-world medication use obtained from more traditional methodologies. Finally, it can allow for access to information about drug misuse and diversion. To date, the latter 2 of these have been realized. Although regulators from the Food and Drug Administration and the United Kingdom's Medicines and Healthcare Products Regulatory Agency participated in the think tank along with representatives from industry, academia, and patient groups, this article should not be construed to constitute regulatory guidance.
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Investigación Biomédica , Fármacos Cardiovasculares/uso terapéutico , Enfermedades Cardiovasculares/tratamiento farmacológico , Monitoreo de Drogas/métodos , Determinación de Punto Final/métodos , Corazón/efectos de los fármacos , HumanosRESUMEN
The etiology of most pediatric hormone deficiency diseases is poorly understood. Children with combined pituitary hormone deficiency (CPHD) have insufficient levels of multiple anterior pituitary hormones causing short stature, metabolic disease, pubertal failure, and often have associated nervous system symptoms. Mutations in developmental regulatory genes required for the specification of the hormone-secreting cell types of the pituitary gland underlie severe forms of CPHD. To better understand these diseases, we have created a unique mouse model of CPHD with a targeted knockin mutation (Lhx3 W227ter), which is a model for the human LHX3 W224ter disease. The LHX3 gene encodes a LIM-homeodomain transcription factor, which has essential roles in pituitary and nervous system development in mammals. The introduced premature termination codon results in deletion of the carboxyl terminal region of the LHX3 protein, which is critical for pituitary gene activation. Mice that lack all LHX3 function do not survive beyond birth. By contrast, the homozygous Lhx3 W227ter mice survive, but display marked dwarfism, thyroid disease, and female infertility. Importantly, the Lhx3 W227ter mice have no apparent nervous system deficits. The Lhx3 W227ter mouse model provides a unique array of hormone deficits and facilitates experimental approaches that are not feasible with human patients. These experiments demonstrate that the carboxyl terminus of the LHX3 transcription factor is not required for viability. More broadly, this study reveals that the in vivo actions of a transcription factor in different tissues are molecularly separable.
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Modelos Animales de Enfermedad , Proteínas de Homeodominio/metabolismo , Hipopituitarismo/etiología , Modelos Biológicos , Hormonas Hipofisarias/deficiencia , Animales , Western Blotting , Codón sin Sentido/genética , Femenino , Técnicas de Sustitución del Gen , Técnicas Histológicas , Proteínas de Homeodominio/genética , Humanos , Inmunohistoquímica , Proteínas con Homeodominio LIM , Masculino , Ratones , Ratones Transgénicos , Reacción en Cadena de la Polimerasa , Factores de TranscripciónRESUMEN
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.
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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 terapéuticoRESUMEN
PURPOSE: Greater medication adherence and persistence have been associated with improved glycemic control in patients with type 2 diabetes mellitus. This study compared adherence, persistence, and treatment patterns among patients naïve to glucagon-like peptide 1 receptor agonists initiating once-weekly injectable treatment with dulaglutide versus semaglutide over 6-month (6M) and 12-month (12M) follow-up periods. METHODS: This retrospective, observational cohort study used administrative claims data from three IBM MarketScan research databases. Data from adult patients with type 2 diabetes newly initiating treatment with dulaglutide or semaglutide between January 2018 and January 2020 (index date was defined as the earliest fill date), without evidence of glucagon-like peptide 1 receptor agonist use in the 6M baseline period, and with continuous enrollment in the 6M baseline and 6M or 12M follow-up period were included. Dulaglutide initiators were propensity score-matched, in a 1:1 ratio, to semaglutide initiators in each 6M and 12M follow-up cohort (26,284 and 13,837 pairs, respectively). FINDINGS: In the matched cohorts, baseline characteristics were balanced; the mean age was 53 years, and 50% of patients were women. Compared to semaglutide initiators, dulaglutide initiators were more adherent (6M, 63.4% vs 47.8%; 12M, 54.4% vs 43.3%; both, P < 0.0001), more persistent on therapy (6M, 72% vs 62%, 12M, 55.5% vs 45.3%, both, P < 0.001), and had more mean days of persistence (6M, 145 vs 132, 12M, 254.3 vs 220.7; both, P < 0.001). IMPLICATIONS: At both 6M and 12M follow-up, dulaglutide initiators had significantly greater adherence and greater persistence compared with matched semaglutide initiators.
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Diabetes Mellitus Tipo 2 , Adulto , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Femenino , Péptido 1 Similar al Glucagón , Péptidos Similares al Glucagón/efectos adversos , Péptidos Similares al Glucagón/análogos & derivados , Humanos , Hipoglucemiantes/uso terapéutico , Fragmentos Fc de Inmunoglobulinas , Masculino , Persona de Mediana Edad , Proteínas Recombinantes de Fusión , Estudios RetrospectivosRESUMEN
INTRODUCTION: The administration of medications targeting type 2 diabetes mellitus (T2D) has evolved over time. As injection delivery systems continue to evolve, it is necessary to understand patients' perceptions of currently available treatments. The objective of this study was to examine the patient perspective of injectable treatment for T2D and identify characteristics of these treatments that are most important to patients. METHODS: Data were collected via an online survey study with a sample of individuals in the UK and US who were treated for T2D with injectable medication. The survey was designed to elicit perceptions of the treatment process for injectable glucagon-like peptide 1 (GLP-1) receptor agonists and insulin. RESULTS: The sample included 504 participants (251 UK, 253 US). Approximately half (50.4%) were treated with a GLP-1 receptor agonist and half (49.6%) were treated with insulin. Respondents were presented with a list of 17 characteristics of injectable medication and asked to indicate which were most important to them. Respondents most frequently selected confidence in administering the correct dose (n = 300, 59.5%); ease of selecting the correct dose (n = 268, 53.2%); overall ease of using the injection device (n = 239, 47.4%); frequency of injections (n = 223, 44.2%); and ease of carrying the device when necessary to inject away from home (n = 190, 37.7%). Characteristics least frequently cited as important included dose escalation (n = 79, 15.7%); handling the needle (n = 74, 14.7%); connectivity to an electronic device (n = 70, 13.9%); and the time required to prepare and inject each dose (n = 62, 12.3%). CONCLUSION: Results of this survey suggest that patients prioritize some attributes of injectable treatments over others. These findings may have implications for clinical practice and development of injection devices.
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PURPOSE: This study examines the relationship between timing of initiation on a glucagon-like peptide-1 receptor agonist (GLP-1 RA) and glycosylated hemoglobin (HbA1c) values. METHODS: The IBM MarketScan databases were used to identify adults with type 2 diabetes mellitus (T2DM) who initiated GLP-1 RA therapy and had multiple recorded HbA1c results. Time to GLP-1 RA initiation was proxied by the number of classes of glucose-lowering agents prescribed in the 2 years before GLP-1 RA initiation, with fewer glucose-lowering agents indicating initiation of a GLP-1 RA earlier in disease progression. Paired t tests examined differences in HbA1c values from preperiod to 2-year postperiod. Multivariable analyses examined the relationship between time to GLP-1 RA initiation and postperiod HbA1c values. FINDINGS: Initiation on a GLP-1 RA was associated with a 0.6% reduction in HbA1c values over 2 years (P < 0.0001). Earliest starts were associated with a 1.3% reduction in HbA1c levels (P < 0.0001) and the highest likelihood of achieving a postperiod HbA1c level <7% (odds ratio, 4.9; 95% CI, 3.0-8.1). IMPLICATIONS: Results indicate that although initiation on a GLP-1 RA is generally associated with reduced HbA1c levels, there may be additional clinical benefits associated with earlier initiation of a GLP-1 RA.
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Diabetes Mellitus Tipo 2/tratamiento farmacológico , Receptor del Péptido 1 Similar al Glucagón/agonistas , Hemoglobina Glucada/análisis , Bases de Datos Factuales , Femenino , Humanos , Hipoglucemiantes/uso terapéutico , Masculino , Persona de Mediana Edad , Estudios RetrospectivosRESUMEN
INTRODUCTION: Randomized controlled trials (RCTs) have demonstrated the efficacy of dulaglutide in adults with type 2 diabetes mellitus (T2DM), but results may not be generalizable in routine practice. This pragmatic literature review aimed to summarize real-world evidence (RWE) for dulaglutide. METHODS: The MEDLINE, EMBASE, NHS Economic Evaluation Database, and Health Technology Assessment databases were searched from January 2014 to July 2019 for studies providing RWE for dulaglutide in adults with T2DM regarding at least one outcome of interest (change in glycated hemoglobin [HbA1c]; weight; adherence; persistence; discontinuation; costs; healthcare resource utilization; health-related quality of life; patient satisfaction; and preference). Relevant congress abstracts were identified from EMBASE. RESULTS: A total of 29 studies (11 articles; 18 abstracts) were included. RWE for dulaglutide was not identified for all outcomes of interest. Dulaglutide reduced HbA1c from baseline to 3-24 months by 0.5-2.2% across studies (n = 20), and 23.4-55.7% of patients achieved HbA1c < 7.0%. Weight was reduced by 2.1-6.4 kg across studies of 3-12 months (n = 15). Based on outcomes from ten studies, 27.2-61.0% of dulaglutide patients were adherent. Mean persistence was 146-152 days and > 250 days in 6- and 12-month studies, respectively. Most studies reported discontinuation rates of 26.2-37.0%. Adherence and persistence were consistently reported to be greater in dulaglutide-treated patients in RW settings compared with other glucagon-like peptide-1 receptor agonists. Dulaglutide was associated with lower costs per 1% reduction in HbA1c compared with exenatide, liraglutide, or basal insulin (n = 3 studies). CONCLUSION: Evidence from RWE studies suggests that dulaglutide may be associated with clinically relevant reductions in HbA1c, with a favorable adherence, persistence, and discontinuation profile in patients with T2DM in routine clinical practice. These findings provide additional insights regarding the potential value of dulaglutide in real-world settings that may assist healthcare decision makers in the delivery of patient-centered care.
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The EU is a member of the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH), and therefore adopts the ICH Guidelines, including the ICH M3 Guideline on Nonclinical Safety Studies. Following the 2016 incident in France with BIA 10-2474, and in light of the substantial evolvement of how early clinical development has been undertaken during the last 10 years, for example, conducting integrated (FIH) studies that include multiple parts (eg, single ascending doses, multiple ascending doses, food effect), EMA decided to update the existing 2007 FIH guideline. The key revisions to the 2007 guideline, now titled "Guideline on Strategies to Identify and Mitigate Risks for First-in-Human and Early Clinical Trials With Investigational Medicinal Products," include additional information. The revision reinforces the importance and impact of pharmacologic data, which supports the intended efficacy of the compound, risk assessment, and protocol design. The updates, effective February 2018, are intended to provide additional guidance and clarity for Sponsors developing FIH and early phase clinical research programs, and ultimately support subject safety. At the 2018 DIA Europe Annual Meeting in Basel, Switzerland, European regulators, industry representatives and academics convened a DIAlogue Session on April 17 to discuss how the revised 2017 guideline is being applied, and to establish recommendations for its application. Using two case studies as examples, the session participants discussed the nonclinical and clinical considerations for applying the newly revised recommendations, and interacted with a panel including regulators and industry representatives. The proceedings from this session reflect practical considerations for the implementation of the revised guideline.
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Preparaciones Farmacéuticas , Europa (Continente) , Humanos , SuizaRESUMEN
Epidemiological data and results from animal studies indicate that imbalances in maternal nutrition impact the expression of metabolic disorders in the offspring. We tested the hypothesis that consumption of excess saturated fats during pregnancy and lactation contributes to adult metabolic dysfunction and that these disturbances can be further influenced by the postweaning diet. Adult male offspring from chow-fed dams were compared with males from dams fed a diet high in saturated fat (45 kcal/100 kcal) before mating, pregnancy, and lactation. Offspring were weaned to a standard chow diet or high fat diet. Animals were killed at 120 days after a 24-h fast. Body weight, energy intake, fat deposition, serum leptin, and insulin were significantly higher in offspring from control or high-fat dams if fed a high-fat diet from weaning to adulthood. Only fat-fed offspring from fat-fed dams were hyperglycemic. Leptin receptor, proopiomelanocortin, and neuropeptide Y (NPY) were also significantly increased in offspring exposed to excess saturated fat during gestation and into adulthood, whereas NPY(1) receptor was downregulated. Signal transducer and activator of transcription 3 mRNA level was significantly higher in offspring from high-fat-fed dams compared with controls; however, no change was detected in cocaine and amphetamine-regulated transcript or suppressor of cytokine signaling 3. An increase in agouti-related protein expression did not reach significance. A significant reduction in phosphatidylinositol 3-kinase regulatory subunit (p85alpha) coupled to an upregulation of protein kinase B was observed in offspring from high-fat-fed dams transitioned to chow food, whereas p85alpha expression was significantly increased in high-fat offspring weaned to the high-fat diet. These data support the hypothesis that early life exposure to excess fat is associated with changes in hypothalamic regulation of body weight and energy homeostasis and that postweaning diet influences development of metabolic dysfunction and obesity.
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Fenómenos Fisiológicos Nutricionales de los Animales , Grasas de la Dieta/administración & dosificación , Regulación de la Expresión Génica , Hipotálamo/metabolismo , Fenómenos Fisiologicos Nutricionales Maternos , Enfermedades Metabólicas/genética , Efectos Tardíos de la Exposición Prenatal , Adiposidad/genética , Animales , Peso Corporal/genética , Metabolismo Energético/genética , Femenino , Edad Gestacional , Hiperglucemia/genética , Insulina/sangre , Lactancia , Leptina/sangre , Masculino , Enfermedades Metabólicas/metabolismo , Neuropéptidos/genética , Estado Nutricional , Obesidad/genética , Fosfatidilinositol 3-Quinasas/genética , Embarazo , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Factor de Transcripción STAT3/genética , Proteína 3 Supresora de la Señalización de Citocinas , Proteínas Supresoras de la Señalización de Citocinas/genética , DesteteRESUMEN
LHX3 is a LIM-homeodomain transcription factor with critical roles in pituitary and nervous system development. Mutations in the LHX3 gene are associated with pediatric diseases featuring severe hormone deficiencies, hearing loss, developmental delay, and other symptoms. The mechanisms that govern LHX3/Lhx3 transcription are poorly understood. In this study, we examined the role of DNA methylation in the expression status of the mouse Lhx3 gene. Pituitary cells that do not normally express Lhx3 (Pit-1/0 cells) were treated with 5-aza-2'-deoxycytidine, a demethylating reagent. This treatment leads to activation of Lhx3 gene expression suggesting that methylation contributes to Lhx3 regulation. Treatment of Pit-1/0 pituitary cells with a combination of a demethylating reagent and a histone deacetylase inhibitor led to rapid activation of Lhx3 expression, suggesting possible crosstalk between DNA methylation and histone modification processes. To assess DNA methylation levels, treated and untreated Pit-1/0 genomic DNAs were subjected to bisulfite conversion and sequencing. Treated Pit-1/0 cells had decreased methylation at specific sites in the Lhx3 locus compared to untreated cells. Chromatin immunoprecipitation assays demonstrated interactions between the MeCp2 methyl binding protein and Lhx3 promoter regions in the Pit-1/0 cell line. Overall, this study demonstrates that DNA methylation patterns of the Lhx3 gene are associated with its expression status.
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Metilación de ADN , Proteínas con Homeodominio LIM/genética , Factores de Transcripción/genética , Animales , Línea Celular , Expresión Génica/genética , Histonas/genética , Histonas/metabolismo , Proteína 2 de Unión a Metil-CpG/genética , Proteína 2 de Unión a Metil-CpG/metabolismo , Ratones , Hipófisis/metabolismo , Hipófisis/fisiología , Regiones Promotoras Genéticas , ARN Mensajero/genéticaRESUMEN
LIM-homeodomain 3 (LHX3) is a transcription factor required for mammalian pituitary gland and nervous system development. Human patients and animal models with LHX3 gene mutations present with severe pediatric syndromes that feature hormone deficiencies and symptoms associated with nervous system dysfunction. The carboxyl terminus of the LHX3 protein is required for pituitary gene regulation, but the mechanism by which this domain operates is unknown. In order to better understand LHX3-dependent pituitary hormone gene transcription, we used biochemical and mass spectrometry approaches to identify and characterize proteins that interact with the LHX3 carboxyl terminus. This approach identified the LANP/pp32 and TAF-1ß/SET proteins, which are components of the inhibitor of histone acetyltransferase (INHAT) multi-subunit complex that serves as a multifunctional repressor to inhibit histone acetylation and modulate chromatin structure. The protein domains of LANP and TAF-1ß that interact with LHX3 were mapped using biochemical techniques. Chromatin immunoprecipitation experiments demonstrated that LANP and TAF-1ß are associated with LHX3 target genes in pituitary cells, and experimental alterations of LANP and TAF-1ß levels affected LHX3-mediated pituitary gene regulation. Together, these data suggest that transcriptional regulation of pituitary genes by LHX3 involves regulated interactions with the INHAT complex.
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Cromatina/metabolismo , Histona Acetiltransferasas/metabolismo , Histonas/metabolismo , Proteínas con Homeodominio LIM/metabolismo , Hipófisis/metabolismo , Subunidades de Proteína/metabolismo , Factores Asociados con la Proteína de Unión a TATA/metabolismo , Factor de Transcripción TFIID/metabolismo , Factores de Transcripción/metabolismo , Acetilación , Animales , Sitios de Unión , Línea Celular , Cromatina/genética , Regulación de la Expresión Génica , Genes Reporteros , Células HEK293 , Histona Acetiltransferasas/genética , Histonas/genética , Humanos , Proteínas con Homeodominio LIM/genética , Luciferasas , Ratones , Hipófisis/citología , Unión Proteica , Estructura Terciaria de Proteína , Subunidades de Proteína/genética , Transducción de Señal , Factores Asociados con la Proteína de Unión a TATA/genética , Factor de Transcripción TFIID/genética , Factores de Transcripción/genética , Transcripción GenéticaRESUMEN
BACKGROUND/AIMS: Recessive mutations in the LHX3 homeodomain transcription factor gene are associated with developmental disorders affecting the pituitary and nervous system. We describe pediatric patients with combined pituitary hormone deficiency (CPHD) who harbor a novel mutation in LHX3. METHODS: Two female siblings from related parents were examined. Both patients had neonatal complications. The index patient had CPHD featuring deficiencies of GH, LH, FSH, PRL, and TSH, with later onset of ACTH deficiency. She also had a hypoplastic anterior pituitary, respiratory distress, hearing impairment, and limited neck rotation. The LHX3 gene was sequenced and the biochemical properties of the predicted altered proteins were characterized. RESULTS: A novel homozygous mutation predicted to change amino acid 194 from threonine to arginine (T194R) was detected in both patients. This amino acid is conserved in the DNA-binding homeodomain. Computer modeling predicted that the T194R change would alter the homeodomain structure. The T194R protein did not bind tested LHX3 DNA recognition sites and did not activate the α-glycoprotein and PRL target genes. CONCLUSION: The T194R mutation affects a critical residue in the LHX3 protein. This study extends our understanding of the phenotypic features, molecular mechanism, and developmental course associated with mutations in the LHX3 gene.