RESUMEN
Core facilities play a central role in the life sciences by generating data and ensuring quality standards. Their contributions to research should be appropriately acknowledged or cited in research papers.
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Bibliometría , Disciplinas de las Ciencias Biológicas , PublicacionesRESUMEN
CONTEXT: Hyperprolactinemia suppresses gonadotropin-releasing hormone (GnRH)-induced luteinizing hormone (LH) pulses. The hypothalamic neuropeptide kisspeptin potently stimulates the secretion of GnRH. The effects of exogenous kisspeptin administration on GnRH pulse generation in the setting of hyperprolactinemia have not previously been explored. OBJECTIVE: This work aimed to examine the effects of kisspeptin on GnRH secretion, as reflected by LH secretion, in women with hyperprolactinemia. METHODS: Women with hyperprolactinemia (n = 11) participated in two 12-hour visits. Before study visits, participants underwent washout of dopamine agonist and/or combined oral contraceptive. Frequent blood sampling was performed (1 sample was collected every 10 minutes). Visit 1 involved no intervention, to examine baseline LH pulsatility. During visit 2, kisspeptin 112-121 (0.24 nmol/kg) was administered every 1 hour, for 10 hours. At hour 11, one intravenous bolus of GnRH (75 ng/kg) was administered. RESULTS: Repetitive intravenous bolus kisspeptin administration increased the total number of LH pulses in the setting of hyperprolactinemia. The interpulse interval declined during the same time frames. LH pulse amplitude did not change, but the mean LH rose. In 6 participants with progesterone levels suggestive of an anovulatory state, mean LH and estradiol levels increased significantly at visit 2. In the entire cohort, follicle-stimulating hormone and prolactin levels did not change significantly across the 2 visits. A total of 73% of subjects exhibited an LH pulse within 30 minutes of first kisspeptin dose. CONCLUSION: Kisspeptin is capable of stimulating hypothalamic GnRH-induced LH pulses in the setting of hyperprolactinemia.
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Hiperprolactinemia , Kisspeptinas , Femenino , Hormona Folículo Estimulante , Hormona Liberadora de Gonadotropina/farmacología , Humanos , Hiperprolactinemia/tratamiento farmacológico , Kisspeptinas/farmacología , Hormona LuteinizanteRESUMEN
RNA binding proteins (RBPs) are key arbiters of post-transcriptional regulation and are found to be found dysregulated in hematological malignancies. Here, we identify the RBP RBMX and its retrogene RBMXL1 to be required for murine and human myeloid leukemogenesis. RBMX/L1 are overexpressed in acute myeloid leukemia (AML) primary patients compared to healthy individuals, and RBMX/L1 loss delayed leukemia development. RBMX/L1 loss lead to significant changes in chromatin accessibility, as well as chromosomal breaks and gaps. We found that RBMX/L1 directly bind to mRNAs, affect transcription of multiple loci, including CBX5 (HP1α), and control the nascent transcription of the CBX5 locus. Forced CBX5 expression rescued the RBMX/L1 depletion effects on cell growth and apoptosis. Overall, we determine that RBMX/L1 control leukemia cell survival by regulating chromatin state through their downstream target CBX5. These findings identify a mechanism for RBPs directly promoting transcription and suggest RBMX/L1, as well as CBX5, as potential therapeutic targets in myeloid malignancies.
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Cromatina , Leucemia Mieloide Aguda , Animales , Cromatina/genética , Regulación de la Expresión Génica , Ribonucleoproteínas Nucleares Heterogéneas/genética , Humanos , Leucemia Mieloide Aguda/genética , Ratones , Proteínas de Unión al ARN/genética , Factores de Transcripción/genéticaRESUMEN
Influenza is a leading cause of death in the elderly, and the vaccine protects only a fraction of this population. A key aspect of antibody-mediated anti-influenza virus immunity is adaptation to antigenically distinct epitopes on emerging strains. We examined factors contributing to reduced influenza vaccine efficacy in the elderly and uncovered a dramatic reduction in the accumulation of de novo immunoglobulin gene somatic mutations upon vaccination. This reduction is associated with a significant decrease in the capacity of antibodies to target the viral glycoprotein, hemagglutinin (HA), and critical protective epitopes surrounding the HA receptor-binding domain. Immune escape by antigenic drift, in which viruses generate mutations in key antigenic epitopes, becomes highly exaggerated. Because of this reduced adaptability, most B cells activated in the elderly cohort target highly conserved but less potent epitopes. Given these findings, vaccines driving immunoglobulin gene somatic hypermutation should be a priority to protect elderly individuals.