Sensorineural correlates of failed functional recovery after natural regeneration of vestibular hair cells in adult mice.

Vestibular hair cells (HCs) are mechanoreceptors that sense head motions by modulating the firing rate of vestibular ganglion neurons (VGNs), whose central processes project to vestibular nucleus neurons (VNNs) and cerebellar neurons. We explored vestibular function after HC destruction in adult Pou4f3+/DTR (DTR) mice, in which injections of high-dose (50 ng/g) diphtheria toxin (DT) destroyed most vestibular HCs within 2 weeks. At that time, DTR mice had lost the horizontal vestibulo-ocular reflex (aVORH), and their VNNs failed to upregulate nuclear cFos expression in response to a vestibular stimulus (centrifugation). Five months later, 21 and 14% of HCs were regenerated in utricles and horizontal ampullae, respectively. The vast majority of HCs present were type II. This degree of HC regeneration did not restore the aVORH or centrifugation-evoked cFos expression in VNNs. The failure to regain vestibular pathway function was not due to degeneration of VGNs or VNNs because normal neuron numbers were maintained after HC destruction. Furthermore, sinusoidal galvanic stimulation at the mastoid process evoked cFos protein expression in VNNs, indicating that VGNs were able to regulate VNN activity after HC loss. aVORH and cFos responses in VNNs were robust after low-dose (25 ng/g) DT, which compared to high-dose DT resulted in a similar degree of type II HC death and regeneration but spared more type I HCs in both organs. These findings demonstrate that having more type I HCs is correlated with stronger responses to vestibular stimulation and suggest that regenerating type I HCs may improve vestibular function after HC loss.

17-ß Estradiol up-regulates energy metabolic pathways, cellular proliferation and tumor invasiveness in ER+ breast cancer spheroids.

Several biological processes related to cancer malignancy are regulated by 17-ß estradiol (E2) in ER+-breast cancer. To establish the role of E2 on the atypical cancer energy metabolism, a systematic study analyzing transcription factors, proteins, and fluxes associated with energy metabolism was undertaken in multicellular tumor spheroids (MCTS) from human ER+ MCF-7 breast cancer cells. At E2 physiological concentrations (10 and 100 nM for 24 h), both ERα and ERß receptors, and their protein target pS2, increased by 0.6-3.5 times vs. non-treated MCTS, revealing an activated E2/ER axis. E2 also increased by 30-470% the content of several transcription factors associated to mitochondrial biogenesis and oxidative phosphorylation (OxPhos) (p53, PGC1-α) and glycolytic pathways (HIF1-α, c-MYC). Several OxPhos and glycolytic proteins (36-257%) as well as pathway fluxes (48-156%) significantly increased being OxPhos the principal ATP cellular supplier (>75%). As result of energy metabolism stimulation by E2, cancer cell migration and invasion processes and related proteins (SNAIL, FN, MM-9) contents augmented by 24-189% vs. non-treated MCTS. Celecoxib at 10 nM blocked OxPhos (60%) as well as MCTS growth, cell migration and invasiveness (>40%); whereas the glycolytic inhibitor iodoacetate (0.5 µM) and doxorubicin (70 nM) were innocuous. Our results show for the first time using a more physiological tridimensional cancer model, resembling the initial stages of solid tumors, that anti-mitochondrial therapy may be useful to deter hormone-dependent breast carcinomas.

Reporte de una nueva mutación en Colombia: un paciente con síndrome de Kabuki / Report of a new mutation in Colombia in a patient with Kabuki Syndrome

RESUMEN Introducción: el síndrome de Kabuki es un desorden pediátrico congénito de origen genético. Los pacientes presentan anormalidades morfológicas como paladar hendido, globos oculares prominentes, eversión del tercio externo del párpado inferior, persistencia de cojinetes dactilares y anormalidades vertebrales. La mayoría cursan con dificultad del aprendizaje. Objetivo: reportar un caso pediátrico de síndrome de Kabuki y fomentar el reconocimiento del fenotipo asociado para facilitar su diagnóstico oportuno. Caso Clínico: paciente masculino de 9 años con características clínicas y diagnóstico genético probable para síndrome de Kabuki. Presenta fisuras palpebrales largas, paladar en ojival, baja implantación auricular, persistencia de almohadillas en pulpejos de dedos, talla baja y colangitis esclerosante primaria. Conclusión: el síndrome de Kabuki tipo 1, se caracteriza por alteraciones faciales que inducen una sospecha diagnóstica. El paciente reportado presentaba múltiples hallazgos descritos. En el estudio genético realizado se considera la variante identificada en el gen KMT2D, probablemente patogénica.

SUMMARY Introduction: Kabuki Syndrome is a pediatric congenital disorder of genetic origin. These patients present morphological abnormalities such as cleft palate, prominent eyeballs, persistence of fingerpads, and vertebral abnormalities. Most also have learning difficulty. Objective: Report a pediatric case of Kabuki Syndrome to increase the recognition of the phenotype associated with it and the likelihood of a diagnosis with the use of a clinical case report. Case report: A nine-year-old male patient with clinical characteristics and probable genetic diagnosis of Kabuki Syndrome. He exhibits elongated eyelids, cleft palate, low auricular implantation, persistence of fingerpads, reduced height, and primary sclerosing cholangitis. Conclusion: Diagnostic suspicion of type one Kabuki Syndrome is characterized mainly by facial alterations. The following patient presents multiple distinctive characteristics described in literature. A genetic study considers the gene KMT2D a possible pathologic genetic variant of the disease.

Disfunción edoltelial inducida por hipercolesterolemia: esudio in vitroen un modelo animal / Endothelial dysfunction induced by hypercholesterolemia: in vitro study ina animal model

Los factores de riesgo tradicionales como hipercolesterolemia afectan la producción endotelial o acción de sustancias vasoactivas fundamentales como el óxido nítrico (NO). Este fenómeno tiene efectos proa terogénicos y protombóricos. El objetivo del presente estudio fue evaluar los efectos in vitro de la hipercolesterolemia sobre la función endotelial y la formación de placa ateroesclerótica en tejido aórtico proveniente de conejos hipercolesterolémicos.Los resultados encontrados sugieren que los niveles elevados de colesterol sérico producen una alteración en la vasodilatación arterial dependiente de endotelio funcional, la cual se presenta sin cambios morfológicos de las células endoteliales. Se corrobora que la hipercolesterolemia es un factor de riesgo independiente de ateroesclerosis el cual contribuye a la disfunción como evento inicial en la génesis del proceso