"MiR-7 controls cholesterol biosynthesis through posttranscriptional regulation of DHCR24 expression".

Dysregulation of cholesterol homeostasis is associated with several pathologies including cardiovascular diseases and neurological disorders such as Alzheimer's disease (AD). MicroRNAs (miRNAs) have emerged as key post-transcriptional regulators of cholesterol metabolism. We previously established the role of miR-7 in regulating insulin resistance and amyloidosis, which represents a common pathological feature between type 2 diabetes and AD. We show here an additional metabolic function of miR-7 in cholesterol biosynthesis. We found that miR-7 blocks the last steps of the cholesterol biosynthetic pathway in vitro by targeting relevant genes including DHCR24 and SC5D posttranscriptionally. Intracranial infusion of miR-7 on an adeno-associated viral vector reduced the expression of DHCR24 in the brain of wild-type mice, supporting in vivo miR-7 targeting. We also found that cholesterol regulates endogenous levels of miR-7 in vitro, correlating with transcriptional regulation through SREBP2 binding to its promoter region. In parallel to SREBP2 inhibition, the levels of miR-7 and hnRNPK (the host gene of miR-7) were concomitantly reduced in brain in a mouse model of Niemann Pick type C1 disease and in murine fatty liver, which are both characterized by intracellular cholesterol accumulation. Taken together, the results establish a novel regulatory feedback loop by which miR-7 modulates cholesterol homeostasis at the posttranscriptional level, an effect that could be exploited for therapeutic interventions against prevalent human diseases.

Role of miR-199a-5p in the post-transcriptional regulation of ABCA1 in response to hypoxia in peritoneal macrophages.

Hypoxia is a crucial factor contributing to maintenance of atherosclerotic lesions. The ability of ABCA1 to stimulate the efflux of cholesterol from cells in the periphery, particularly foam cells in atherosclerotic plaques, is an important anti-atherosclerotic mechanism. The posttranscriptional regulation by miRNAs represents a key regulatory mechanism of a number of signaling pathways involved in atherosclerosis. Previously, miR-199a-5p has been shown to be implicated in the endocytic and retrograde intracellular transport. Although the regulation of miR-199a-5p and ABCA1 by hypoxia has been already reported independently, the role of miR-199a-5p in macrophages and its possible role in atherogenic processes such us regulation of lipid homeostasis through ABCA1 has not been yet investigated. Here, we demonstrate that both ABCA1 and miR-199a-5p show an inverse regulation by hypoxia and Ac-LDL in primary macrophages. Moreover, we demonstrated that miR-199a-5p regulates ABCA1 mRNA and protein levels by directly binding to its 3'UTR. As a result, manipulation of cellular miR-199a-5p levels alters ABCA1 expression and cholesterol efflux in primary mouse macrophages. Taken together, these results indicate that the correlation between ABCA1-miR-199a-5p could be exploited to control macrophage cholesterol efflux during the onset of atherosclerosis, where cholesterol alterations and hypoxia play a pathogenic role.

New Insights on the Regulation of the Insulin-Degrading Enzyme: Role of microRNAs and RBPs.

The evident implication of the insulin-degrading enzyme (IDE) in Alzheimer's disease (AD) and type 2 diabetes mellitus (T2DM), among its capacity to degrade insulin and amyloid-ß peptide (Aß), suggests that IDE could be an essential link in the relation between hyperinsulinemia, insulin resistance and AD. However, little is known about the cellular and molecular regulation of IDE expression, and even less has been explored regarding the post-transcriptional regulation of IDE, although it represents a great molecular target of interest for therapeutic treatments. We recently described that miR-7, a novel candidate for linking AD and T2DM at the molecular level, regulates IDE and other key genes in both pathologies, including some key genes involved in the insulin signaling pathway. Here, we explored whether other miRNAs as well as other post-transcriptional regulators, such as RNA binding proteins (RBP), could potentially participate in the regulation of IDE expression in vitro. Our data showed that in addition to miR-7, miR-125, miR-490 and miR-199 regulate IDE expression at the post-transcriptional level. Moreover, we also found that IDE contains multiple potential binding sites for several RBPs, and a narrow-down prediction analysis led us to speculate on a novel regulation of IDE by RALY and HuD. Taken together, these results demonstrate the novel players controlling IDE expression that could represent potential therapeutical targets to treat several metabolic diseases with a high impact on human health, including AD and T2DM.

Posttranscriptional Regulation of Insulin Resistance: Implications for Metabolic Diseases.

Insulin resistance defines an impairment in the biologic response to insulin action in target tissues, primarily the liver, muscle, adipose tissue, and brain. Insulin resistance affects physiology in many ways, causing hyperglycemia, hypertension, dyslipidemia, visceral adiposity, hyperinsulinemia, elevated inflammatory markers, and endothelial dysfunction, and its persistence leads to the development metabolic disease, including diabetes, obesity, cardiovascular disease, or nonalcoholic fatty liver disease (NAFLD), as well as neurological disorders such as Alzheimer's disease. In addition to classical transcriptional factors, posttranscriptional control of gene expression exerted by microRNAs and RNA-binding proteins constitutes a new level of regulation with important implications in metabolic homeostasis. In this review, we describe miRNAs and RBPs that control key genes involved in the insulin signaling pathway and related regulatory networks, and their impact on human metabolic diseases at the molecular level, as well as their potential use for diagnosis and future therapeutics.

Evaluation of Neurosecretome from Mesenchymal Stem Cells Encapsulated in Silk Fibroin Hydrogels.

Physical and cognitive disabilities are hallmarks of a variety of neurological diseases. Stem cell-based therapies are promising solutions to neuroprotect and repair the injured brain and overcome the limited capacity of the central nervous system to recover from damage. It is widely accepted that most benefits of different exogenously transplanted stem cells rely on the secretion of different factors and biomolecules that modulate inflammation, cell death and repair processes in the damaged host tissue. However, few cells survive in cerebral tissue after transplantation, diminishing the therapeutic efficacy. As general rule, cell encapsulation in natural and artificial polymers increases the in vivo engraftment of the transplanted cells. However, we have ignored the consequences of such encapsulation on the secretory activity of these cells. In this study, we investigated the biological compatibility between silk fibroin hydrogels and stem cells of mesenchymal origin, a cell population that has gained increasing attention and popularity in regenerative medicine. Although the survival of mesenchymal stem cells was not affected inside hydrogels, this biomaterial format caused adhesion and proliferation deficits and impaired secretion of several angiogenic, chemoattractant and neurogenic factors while concurrently potentiating the anti-inflammatory capacity of this cell population through a massive release of TGF-Beta-1. Our results set a milestone for the exploration of engineering polymers to modulate the secretory activity of stem cell-based therapies for neurological disorders.

Implantación del listado de verificación de seguridad quirúrgica en un hospital comarcal / Implementation of the surgical safety checklist in a regional hospital

OBJETIVO: describir el grado de cumplimentación del listado de verific ción de seguridad quirúrgica (LVSQ) en el servicio de quirófano de un hospital comarcal. MÉTODO: estudio descriptivo transversal llevado a cabo en el Hospital Santos Reyes de Aranda de Duero (Burgos) entre mayo de 2015 y mayo de 2016. Se realizó un muestreo aleatorio simple de 750 individuos sometidos a cirugía programada para la revisión de los LVSQ contenidos en sus historias clínicas. Se efectuó un análisis descriptivo con frecuencias absolutas y porcentajes de los ítems del listado categorizados por el momento del procedimiento quirúrgico (antes de la inducción anestésica, antes de la incisión cutánea y antes de la salida de quirófano) y por el profesional responsable de su cumplimentación (enfermera, anestesista y cirujano). RESULTADOS: se estudiaron un total de 604 listados de verificaciónde seguridad quirúrgica. Se observó una mayor cumplimentación del LVSQ en los momentos anteriores a la inducción anestésica y a la incisión cutánea que antes de la salida de quirófano y siempre en aquellos ítems cumplimentados por enfermeras. La cumplimentación de las cuestiones propias de las enfermeras rondó el 88%, fue del 49% en el caso de los ítems propios de los anestesistas y del 46,9% en los asignados a cirujanos. Fue necesario corregir el consentimiento informado en el 4,3% de las intervenciones. CONCLUSIONES: hay diferencias en la cumplimentación del LVSQ en función del momento quirúrgico y del profesional responsable. La formación del personal implicado, así como la implicación de los líderes institucionales, podría jugar un papel para conseguir una mayor adherencia en la cumplimentación

OBJECTIVE: to describe the level of compliance with the Surgical Safety Checklist (SSCL) at the Operating Room in a regional hospital. METHOD: a descriptive cross-sectional study conducted at the Hospital Santos Reyes of Aranda de Duero (Burgos) between May, 2015 and May, 2016. Simple random sampling was conducted on 750 individuals undergoing scheduled surgery, in order to review the SSCLs included in their clinical records. Descriptive analysis was conducted with absolute frequencies and percentages of the list items, classified by time point during the surgical procedure (before anesthetic induction, before skin incision, and before leaving the operating room), and by professional responsible for completion (nurse, anesthetist and surgeon). RESULTS: in total, 604 Surgical Safety Checklists were studied. Higher SSCL compliance was observed a the time point before anesthetic induction and skin incision, than before leaving the operating room, and always in those items completed by nurses. Completion of items by nurses reached about 88%; in the case of anesthetists, it was 49%, and 46.9% in those items assigned to surgeons. It was necessary to correct Informed Consents in 4.3% of interventions. CONCLUSIONS: there are differences in SSCL compliance according to the surgical time and the professional in charge. Training for the staff involved, as well as involvement by institution leaders, could play a role in order to achieve a higher adherence in terms of compliance