Pharmacological recruitment of aldehyde dehydrogenase 3A1 (ALDH3A1) to assist ALDH2 in acetaldehyde and ethanol metabolism in vivo.

Correcting a genetic mutation that leads to a loss of function has been a challenge. One such mutation is in aldehyde dehydrogenase 2 (ALDH2), denoted ALDH2*2. This mutation is present in ∼ 0.6 billion East Asians and results in accumulation of toxic acetaldehyde after consumption of ethanol. To temporarily increase metabolism of acetaldehyde in vivo, we describe an approach in which a pharmacologic agent recruited another ALDH to metabolize acetaldehyde. We focused on ALDH3A1, which is enriched in the upper aerodigestive track, and identified Alda-89 as a small molecule that enables ALDH3A1 to metabolize acetaldehyde. When given together with the ALDH2-specific activator, Alda-1, Alda-89 reduced acetaldehyde-induced behavioral impairment by causing a rapid reduction in blood ethanol and acetaldehyde levels after acute ethanol intoxication in both wild-type and ALDH2-deficient, ALDH2*1/*2, heterozygotic knock-in mice. The use of a pharmacologic agent to recruit an enzyme to metabolize a substrate that it usually does not metabolize may represent a novel means to temporarily increase elimination of toxic agents in vivo.

Aldehyde dehydrogenase 2 activation and coevolution of its εPKC-mediated phosphorylation sites.

BACKGROUND: Mitochondrial aldehyde dehydrogenase 2 (ALDH2) is a key enzyme for the metabolism of many toxic aldehydes such as acetaldehyde, derived from alcohol drinking, and 4HNE, an oxidative stress-derived lipid peroxidation aldehyde. Post-translational enhancement of ALDH2 activity can be achieved by serine/threonine phosphorylation by epsilon protein kinase C (εPKC). Elevated ALDH2 is beneficial in reducing injury following myocardial infarction, stroke and other oxidative stress and aldehyde toxicity-related diseases. We have previously identified three εPKC phosphorylation sites, threonine 185 (T185), serine 279 (S279) and threonine 412 (T412), on ALDH2. Here we further characterized the role and contribution of each phosphorylation site to the enhancement of enzymatic activity by εPKC. METHODS: Each individual phosphorylation site was mutated to a negatively charged amino acid, glutamate, to mimic a phosphorylation, or to a non-phosphorylatable amino acid, alanine. ALDH2 enzyme activities and protection against 4HNE inactivation were measured in the presence or absence of εPKC phosphorylation in vitro. Coevolution of ALDH2 and its εPKC phosphorylation sites was delineated by multiple sequence alignments among a diverse range of species and within the ALDH multigene family. RESULTS: We identified S279 as a critical εPKC phosphorylation site in the activation of ALDH2. The critical catalytic site, cysteine 302 (C302) of ALDH2 is susceptible to adduct formation by reactive aldehyde, 4HNE, which readily renders the enzyme inactive. We show that phosphomimetic mutations of T185E, S279E and T412E confer protection of ALDH2 against 4HNE-induced inactivation, indicating that phosphorylation on these three sites by εPKC likely also protects the enzyme against reactive aldehydes. Finally, we demonstrate that the three ALDH2 phosphorylation sites co-evolved with εPKC over a wide range of species. Alignment of 18 human ALDH isozymes, indicates that T185 and S279 are unique ALDH2, εPKC specific phosphorylation sites, while T412 is found in other ALDH isozymes. We further identified three highly conserved serine/threonine residues (T384, T433 and S471) in all 18 ALDH isozymes that may play an important phosphorylation-mediated regulatory role in this important family of detoxifying enzymes. CONCLUSION: εPKC phosphorylation and its coevolution with ALDH2 play an important role in the regulation and protection of ALDH2 enzyme activity.

Continuous access to snacks from weaning onwards in female rats causes weight gain, insulin insensitivity, and sustained leptin resistance in adulthood.

A large part of the daily intake of children in the U.S. consists of snacks, with the average child consuming three snacks per day. Despite this, little research has been conducted to determine the metabolic and behavioral effects of snacking. Using a developing female rat model, our studies aimed to determine the effects of snacking during development before the protective effects of estrogen on weight gain would be relevant. Additionally, to determine if snack composition is important, we created one healthy and one unhealthy snacking group provided with chow and three snacks each in addition to a chow-only group. We found that both snacking groups experienced increased weight gain, elevated abdominal fat pad mass, prolonged leptin resistance into adulthood, and insulin insensitivity that was not observed in their non-snacking counterparts. These physiological differences were measured despite both snacking groups having a similar caloric intake as the chow-only group throughout the study. In addition to physiological changes, both snacking groups showed a preference for snacks over chow and ate more often during the inactive light phase than typical for rats, with the unhealthy snacking group presenting this behavioral change earlier than the healthy snacking group. Our results suggest that constant access to palatable snacks, which is often the case for children in western countries, alters feeding behaviors in relation to food choice and time of day when eating occurs. Snacking during development seemed to promote signs of metabolic syndrome in adulthood even when excess caloric intake was not observed. Our work further suggests that development is a vulnerable time for palatable snack presentation when prepubertal females lack the protective effects of estrogen and exhibit reduced leptin feedback on food intake. Thus snacking from weaning onward could be a contributor to the current childhood obesity crisis.

Consentimiento informado en radiología odontológica: un asunto pendiente / Informed consent in dental radiology: a pending matter

Introducción: En el ámbito odontológico es muy común el uso de radiografías intraorales, extraorales e incluso de tomografías computarizadas volumétricas. Las radiografías intraorales presentan una baja dosis de radiación en comparación con las tomografías computarizadas volumétricas que pueden emitir una mayor dosis de radiación con cierto grado de riesgo para los pacientes. A pesar de que se conoce sobre la importancia del uso del consentimiento informado y los riesgos durante estos procedimientos, muy poco se ha reportado sobre la utilización del consentimiento informado en radiología oral y maxilofacial. Objetivo: Analizar los beneficios y los retos de usar el consentimiento informado en radiología odontológica. Comentarios principales: Actualmente, no existe un consenso claro en la comunidad odontológica sobre si se debe obtener el consentimiento informado del paciente antes de que se someta a un examen de imagen con radiación ionizante. Su aplicación de manera repetitiva o prolongada podría afectar al paciente a largo plazo. Consideraciones globales: Existe un consenso universal en resaltar la importancia del consentimiento informado en todo el ámbito de la salud. Sin embargo, en la práctica, su realización puede conllevar ciertas dificultades, tales como la identificación del responsable de su realización, el tiempo que lleva ejecutarla y la preocupación por causar un miedo innecesario en el paciente. Si estas dificultades logran ser superadas, podremos ver los beneficios de tener un consenso claro para la utilización de un consentimiento informado en el área odontológica(AU)

Introduction: In the dental field, the use of intraoral, extraoral and even volumetric computed tomography is very common. Intraoral X-rays have a low dose of radiation compared to volumetric CT scans that can emit a higher dose of radiation with some degree of risk to patients. Although the importance of the use of informed consent and the risks during these procedures are known, very little has been reported about the use of informed consent in oral and maxillofacial radiology. Objective: Analyze the benefits and challenges of using informed consent in dental radiology. Main Comments: Currently, there is no clear consensus in the dental community on whether the patient's informed consent should be obtained before they undergo an imaging examination with ionizing radiation. Its application repetitively or prolongedly could affect the patient in the long term. Global considerations: There is a universal consensus to highlight the importance of informed consent in the entire field of health. However, in practice, its realization can lead to certain difficulties, such as the identification of the person responsible for its implementation, the time it takes to execute it and the concern to cause unnecessary fear in the patient. If these difficulties can be overcome, we can see the benefits of having a clear consensus for the use of informed consent in the dental area(AU)

Targeting aldehyde dehydrogenase activity in head and neck squamous cell carcinoma with a novel small molecule inhibitor.

Chemoresistant cancer cells express high levels of aldehyde dehydrogenases (ALDHs), particularly in head and neck squamous cell carcinoma (HNSCC). The ALDH family of enzymes detoxify both exogenous and endogenous aldehydes. Since many chemotherapeutic agents, such as cisplatin, result in the generation of cytotoxic aldehydes and oxidative stress, we hypothesized that cells expressing high levels of ALDH may be more chemoresistant due to their increased detoxifying capacity and that inhibitors of ALDHs may sensitize them to these drugs. Here, we show that overall ALDH activity is increased with cisplatin treatment of HNSCC and that ALDH3A1 protein expression is particularly enriched in cells treated with cisplatin. Activation of ALDH3A1 by a small molecule activator (Alda-89) increased survival of HNSCC cells treated with cisplatin. Conversely, treatment with a novel small molecule ALDH inhibitor (Aldi-6) resulted in a marked decrease in cell viability, and the combination of Aldi-6 and cisplatin resulted in a more pronounced reduction of cell viability and a greater reduction in tumor burden in vivo than what was observed with cisplatin alone. These data indicate that ALDH3A1 contributes to cisplatin resistance in HNSCC and that the targeting of ALDH, specifically, ALDH3A1, appears to be a promising strategy in this disease.

6-Azido-7-nitro-1,4-dihydroquinoxaline-2,3-dione (ANQX) forms an irreversible bond to the active site of the GluR2 AMPA receptor.

AMPA receptors mediate fast excitatory synaptic transmission and are essential for synaptic plasticity. ANQX, a photoreactive AMPA receptor antagonist, is an important biological probe used to irreversibly inactivate AMPA receptors. Here, using X-ray crystallography and mass spectroscopy, we report that ANQX forms two major products in the presence of the GluR2 AMPAR ligand-binding core (S1S2J). Upon photostimulation, ANQX reacts intramolecularly to form FQX or intermolecularly to form a covalent adduct with Glu705.

Incidencia y tratamiento de las cardiopatías congénitas en San Miguel del Padrón / Incidence and treatment of congenital heart disease in San Miguel del Padrón

Introducción: los defectos congénitos cardiovasculares son en la actualidad con frecuencia, la causa de muerte en los primeros años de vida, y la detección de estos en la etapa fetal, les proporciona a los futuros padres, los conocimientos que les permite tomar una decisión, con respecto a continuar o no con el embarazo. Objetivo: analizar la incidencia y tratamiento de las cardiopatías congénitas, en el municipio San Miguel del Padrón, en el periodo entre enero de 2007 y diciembre de 2010. Métodos: se realizó un estudio descriptivo acerca del diagnóstico prenatal y postnatal de las cardiopatías congénitas, en el municipio San Miguel del Padrón, entre el 1ro de enero de 2007 y el 31 de diciembre de 2010. ..

Introduction: Nowadays, cardiovascular birth defects are often the cause of death in the first years of life, and the detection of these in the fetal stage, provides prospective parents, the knowledge that enables them to make a decision, regarding whether to continue pregnancy. Objective: To analyze incidence and treatment of congenital heart disease in the municipality of San Miguel del Padrón, from January 2007 to December 2010. Methods: We carried out a descriptive study on the prenatal and postnatal diagnosis of congenital heart disease in the municipality of San Miguel del Padrón, from 1st January 2007 to December 31st, 2010. ..

Small-molecule inhibition of TNF-alpha.

We have identified a small-molecule inhibitor of tumor necrosis factor alpha (TNF-alpha) that promotes subunit disassembly of this trimeric cytokine family member. The compound inhibits TNF-alpha activity in biochemical and cell-based assays with median inhibitory concentrations of 22 and 4.6 micromolar, respectively. Formation of an intermediate complex between the compound and the intact trimer results in a 600-fold accelerated subunit dissociation rate that leads to trimer dissociation. A structure solved by x-ray crystallography reveals that a single compound molecule displaces a subunit of the trimer to form a complex with a dimer of TNF-alpha subunits.