Oral administration of phytochemicals protects honey bees against cognitive and motor impairments induced by the insecticide fipronil.

Pollution produced by exposure to pesticides is a major concern for food security because the negative impacts on pollinators. Fipronil, an insecticide broadly used around the globe has been associated with the ongoing decline of bees. With a characteristic neuroactive toxicodynamic, fipronil leads to cognitive and motor impairments at sublethal dosages. Despite of regional bans, multilevel strategies are necessary for the protection of pollinators. Recent evidence suggests that specific nutrients in the diets of bees may induce protection against insecticides. Here, we evaluated whether the administration of three phytochemicals, namely rutin, kaempferol and p-coumaric acid provide protection to the Africanized honey bee Apis mellifera against oral administration of realistic dosages of fipronil. We tested the potential impairment produced by fipronil and the protection induced by the phytochemicals in learning, 24h memory, sucrose sensitivity and motor control. We found that the administration of fipronil induced a concentration-dependent impairment in learning and motor control, but not 24h memory or sucrose sensitivity across a 24h window. We also found that the administration of rutin, p-coumaric acid, kaempferol and the mixture was innocuous and generally offered protection against the impairments induced by fipronil. Overall, our results indicate that bees can be prophylactically protected against insecticides via nutrition, providing an alternative to the ongoing conflict between the use of insecticides and the decline of pollinators. As the studied phytochemicals are broadly present in nectar and pollen, our results suggest that the nutritional composition, and not only its production, should be considered when implementing strategies of conservation via gardens and co-cropping.

Orosomucoid-1 Arises as a Shared Altered Protein in Two Models of Multiple Sclerosis.

Multiple sclerosis (MS) is a complex autoimmune and neurodegenerative disorder that affects the central nervous system (CNS). It is characterized by a heterogeneous disease course involving demyelination and inflammation. In this study, we utilized two distinct animal models, cuprizone (CPZ)-induced demyelination and experimental autoimmune encephalomyelitis (EAE), to replicate various aspects of the disease. We aimed to investigate the differential CNS responses by examining the proteomic profiles of EAE mice during the peak disease (15 days post-induction) and cuprizone-fed mice during the acute phase (38 days). Specifically, we focused on two different regions of the CNS: the dorsal cortex (Cx) and the entire spinal cord (SC). Our findings revealed varied glial, synaptic, dendritic, mitochondrial, and inflammatory responses within these regions for each model. Notably, we identified a single protein, Orosomucoid-1 (Orm1), also known as Alpha-1-acid glycoprotein 1 (AGP1), that consistently exhibited alterations in both models and regions. This study provides insights into the similarities and differences in the responses of these regions in two distinct demyelinating models.

Catalytic Gasification and Reforming of Residual Biomass in a Bench Scale System with Low Cost Catalysts.

This paper demonstrates the effectiveness of using of different catalysts for reforming tars contained in the syngas of biomass gasifiers. The conversion of the tar content allows to obtain high quality syngas and to maximize the gas fraction. A bench scale equipment consisting of an autothermal fluidized bed gasifier and a downstream packed bed reformer was used. Pine sawdust was selected as the feedstock for gasification. TGA analysis showed that the temperature must be above 350 °C to ensure the ignition of the biomass and maintain the process in an autothermal steady-state. Dolomite and pyrolysis char were used to test of the fluidized bed catalysts. In the reformer, dolomite, pyrolysis char, iron doped activated carbon and spent HDS catalyst were used. All catalysts decreased the CO2 concentration in the product gas and increased H2 , CH4 and CO. When iron doped activated carbon is used, tar contents below 60 g/Nm3 in the product gas could be obtained, reaching less than 1 g/Nm3 . The best value of LHV (lower heating value) was obtained with pyrolysis char as a catalyst (4.8 MJ/Nm3 ). The results demonstrate that catalytic biomass gasification with downstream tar reforming with low-cost catalysts is a promising solution for energy applications.

In Situ DRIFTS Analysis during Hydrogenation of 1-Pentyne and Olefin Purification with Ag Nanoparticles.

The catalytic performance of nanoparticles (NPs) of Ag anchored on different supports was evaluated during the selective hydrogenation of 1-pentyne and the purification of a mixture of 1-pentene/1-pentyne (70/30 vol %). The catalysts were identified: Ag/Al (Ag supported on É£-Al2 O3 ), Ag/Al-Mg (Ag supported on É£-Al2 O3 modified with Mg), Ag/Ca (Ag supported on CaCO3 ) and Ag/RX3 (Ag supported on activated carbon-type: RX3). In addition, in situ DRIFTS analysis of 1-pentyne adsorption on each support, catalyst, and 1-pentyne hydrogenation were investigated. The results showed that the synthesized catalysts were active and very selective (≥85 %) for obtaining the desired product (1-pentene). Different adsorbed species (-C≡C- and -C=C-) were observed on the supports and catalysts surface using in situ DRIFT analysis, which can be correlated to the activity and high selectivity reached. The role of the supports and electronic properties over Ag improve the H2 dissociative chemisorption during the hydrogenation reactions; promoting the selectivity and the high catalytic performance. Ag/Al and Ag/Al-Mg were the most active catalysts. This was due to the synergism between the active Ag/Ag+ species and the supports (electronic effects). The results show that Ag/Al and Ag/Al-Mg catalysts have favorable properties and are promising for the alkyne hydrogenation and olefin purification reactions.

Protocol for designing and bioprinting multi-layered constructs to reconstruct an endothelial-epithelial 3D model.

3D bioprinting has opened new possibilities and elevated tissue engineering complexity. Here, we present a protocol to design a 3D model with two cell lineage layers (A549 and HUVEC) to recreate multi-cell constructs. We describe the steps for slicing the constructs, handling hydrogels, and detailing the bioprinting setup. These 3D-bioprinted constructs can be adapted to various cell models-from primary cell cultures to commercial cell lines and induced pluripotent stem cells (IPCs)-and applications, including drug screening and disease modeling. For complete details on the use and execution of this protocol, please refer to Cruz et al.1.

Yeast Chaperone Hsp70-Ssb Modulates a Variety of Protein-Based Heritable Elements.

Prions are transmissible self-perpetuating protein isoforms associated with diseases and heritable traits. Yeast prions and non-transmissible protein aggregates (mnemons) are frequently based on cross-ß ordered fibrous aggregates (amyloids). The formation and propagation of yeast prions are controlled by chaperone machinery. Ribosome-associated chaperone Hsp70-Ssb is known (and confirmed here) to modulate formation and propagation of the prion form of the Sup35 protein [PSI+]. Our new data show that both formation and mitotic transmission of the stress-inducible prion form of the Lsb2 protein ([LSB+]) are also significantly increased in the absence of Ssb. Notably, heat stress leads to a massive accumulation of [LSB+] cells in the absence of Ssb, implicating Ssb as a major downregulator of the [LSB+]-dependent memory of stress. Moreover, the aggregated form of Gγ subunit Ste18, [STE+], behaving as a non-heritable mnemon in the wild-type strain, is generated more efficiently and becomes heritable in the absence of Ssb. Lack of Ssb also facilitates mitotic transmission, while lack of the Ssb cochaperone Hsp40-Zuo1 facilitates both spontaneous formation and mitotic transmission of the Ure2 prion, [URE3]. These results demonstrate that Ssb is a general modulator of cytosolic amyloid aggregation, whose effect is not restricted only to [PSI+].

The complexity of female orgasm and ejaculation.

The anatomy and physiology of the female orgasm are often neglected. The female orgasm is a normal psychophysiological function to all women, and some even can achieve ejaculation as part of the normal physiological response at the height of sexual arousal. The complexity of female sexuality requires a deep understanding of genital anatomy. The clitoris is the principal organ for female pleasure. The vaginal stimulation of the anterior vaginal wall led women to orgasm due to the stimulation of the clitourethrovaginal complex and not due to stimulation of a particular organ called the G spot in the anterior distal vaginal wall. Female ejaculation follows orgasm. It consists of the orgasmic expulsion of a smaller quantity of whitish fluid produced by the female prostate. Squirting can be differentiated from female ejaculation because it is the orgasmic transurethral expulsion of a substantial amount of diluted urine during sexual activity, and it is not considered pathological. The female orgasm is influenced by many aspects such as communication, emotional intimacy, long-standing relationship, adequate body image and self-esteem, proper touching and knowledge of the female body, regular masturbation, male sexual performance, male and female fertility, chronic pain, and capacity to engage in new sexual acts. Stronger orgasms could be achieved when clitoral stimulation, anterior vaginal wall stimulation, and oral sex is involved in the same sexual act.

A call for implementation of the Law 2120 against junk food during pandemic times in Colombia / Llamado a la implementación de la Ley 2120 de 2021 contra la comida chatarra en los tiempos del COVID-19 en Colombia

Durante dos años y medio, tanto en Colombia como en el resto del mundo, hemos enfrentado la pandemia generada por el SARS-CoV-2, agudizando los múltiples problemas de salud pública que venían cursando a manera de sindemias. Tal es el caso de las enfermedades crónicas no transmisibles asociadas, entre otros factores, a los malos hábitos alimenticios, especialmente por el gran consumo de alimentos ultraprocesados y bebidas azucaradas. En julio del 2021, se aprobó la Ley 2120, por medio de la cual se adoptaron medidas para fomentar entornos alimentarios saludables. Entre estas medidas, también se promueve que los alimentos empacados, procesados y que afectan negativamente la salud humana, tengan un sello que identifique sus componentes y valor nutricional para informar a los consumidores sobre el producto que están comprando o consumiendo. Entre las enfermedades más prevalentes en Colombia que afectan la salud bucal, se encuentran las caries y las periodontitis, ambas con factores de riesgo comunes con las enfermedades crónicas no transmisibles. Dados sus costos y prevalencia, dichas enfermedades crónicas no transmisibles resultan primordiales desde un enfoque de gestión del riesgo en salud pública, siendo, quizá, su gravedad mayor durante la pandemia generada por el SARS CoV-2. Asimismo, se especula que la población confinada pudo llegar a consumir más comida chatarra durante la pandemia del COVID-19 en comparación con otros períodos, además, porque en aquellos con enfermedades crónicas no transmisibles, el confinamiento obligado se asocia con mayor sedentarismo y con un menor número de controles médicos regulares, asuntos que se han reportado previamente. La promulgación de la ley de comida chatarra no va a cambiar los hábitos de alimentación de los colombianos "de la noche a la mañana" y, por esto, se necesita con urgencia implementar procesos de educación y sensibilización frente a los efectos adversos de los alimentos procesados y ultraprocesados en la salud.

Durante dos años y medio, tanto en Colombia como en el resto del mundo, hemos enfrentado la pandemia generada por el SARS-CoV-2, agudizando los múltiples problemas de salud pública que venían cursando a manera de sindemias. Tal es el caso de las enfermedades crónicas no transmisibles asociadas, entre otros factores, a los malos hábitos alimenticios, especialmente por el gran consumo de alimentos ultraprocesados y bebidas azucaradas. En julio del 2021, se aprobó la Ley 2120, por medio de la cual se adoptaron medidas para fomentar entornos alimentarios saludables. Entre estas medidas, también se promueve que los alimentos empacados, procesados y que afectan negativamente la salud humana, tengan un sello que identifique sus componentes y valor nutricional para informar a los consumidores sobre el producto que están comprando o consumiendo. Entre las enfermedades más prevalentes en Colombia que afectan la salud bucal, se encuentran las caries y las periodontitis, ambas con factores de riesgo comunes con las enfermedades crónicas no transmisibles. Dados sus costos y prevalencia, dichas enfermedades crónicas no transmisibles resultan primordiales desde un enfoque de gestión del riesgo en salud pública, siendo, quizá, su gravedad mayor durante la pandemia generada por el SARS CoV-2. Asimismo, se especula que la población confinada pudo llegar a consumir más comida chatarra durante la pandemia del COVID-19 en comparación con otros períodos, además, porque en aquellos con enfermedades crónicas no transmisibles, el confinamiento obligado se asocia con mayor sedentarismo y con un menor número de controles médicos regulares, asuntos que se han reportado previamente. La promulgación de la ley de comida chatarra no va a cambiar los hábitos de alimentación de los colombianos "de la noche a la mañana" y, por esto, se necesita con urgencia implementar procesos de educación y sensibilización frente a los efectos adversos de los alimentos procesados y ultraprocesados en la salud.

Simple and efficient protocol to isolate and culture brain microvascular endothelial cells from newborn mice.

The neurovascular unit (NVU) is a multicellular structure comprising of neurons, glial cells, and non-neural cells, and it is supported by a specialized extracellular matrix, the basal lamina. Astrocytes, brain microvascular endothelial cells (BMECs), pericytes, and smooth muscle cells constitute the blood-brain barrier (BBB). BMECs have a mesodermal origin and invade the nervous system early in neural tube development, forming the BBB anatomical core. BMECs are connected by adherent junction complexes composed of integral membrane and cytoplasmic proteins. In vivo and in vitro studies have shown that, given the proximity and relationship with neural cells, BMECs acquire a unique gene expression profile, proteome, and specific mechanical and physical properties compared to endothelial cells from the general vasculature. BMECs are fundamental in maintaining brain homeostasis by regulating transcellular and paracellular transport of fluids, molecules, and cells. Therefore, it is essential to gain in-depth knowledge of the dynamic cellular structure of the cells in the NVU and their interactions with health and disease. Here we describe a significantly improved and simplified protocol using C57BL/6 newborn mice at postnatal day 1 (PND1) to isolate, purify, and culture BMECs monolayers in two different substrates (glass coverslips and transwell culture inserts). In vitro characterization and validation of the BMEC primary culture monolayers seeded on glass or insert included light microscopy, immunolabeling, and gene expression profile. Transendothelial electrical resistance (TEER) measurement and diffusion test were used as functional assays for adherent junction complexes and integrity and permeability of BMECs monolayers. The protocol presented here for the isolation and culture of BMECs is more straightforward than previously published protocols and yields a high number of purified cells. Finally, we tested BMECs function using the oxygen-glucose deprivation (OGD) model of hypoxia. This protocol may be suitable as a bioscaffold for secondary cell seeding allowing the study and better understanding of the NVU.

Llamado a la implementación de la Ley 2120 de 2021 contra la comida chatarra en los tiempos del COVID-19 en Colombia / A call for implementation of the Law 2120 against junk food during pandemic times in Colombia

Durante dos años y medio, tanto en Colombia como en el resto del mundo, hemos enfrentado la pandemia generada por el SARS-CoV-2, agudizando los múltiples problemas de salud pública que venían cursando a manera de sindemias. Tal es el caso de las enfermedades crónicas no transmisibles asociadas, entre otros factores, a los malos hábitos alimenticios, especialmente por el gran consumo de alimentos ultraprocesados y bebidas azucaradas. En julio del 2021, se aprobó la Ley 2120, por medio de la cual se adoptaron medidas para fomentar entornos alimentarios saludables. Entre estas medidas, también se promueve que los alimentos empacados, procesados y que afectan negativamente la salud humana, tengan un sello que identifique sus componentes y valor nutricional para informar a los consumidores sobre el producto que están comprando o consumiendo. Entre las enfermedades más prevalentes en Colombia que afectan la salud bucal, se encuentran las caries y las periodontitis, ambas con factores de riesgo comunes con las enfermedades crónicas no transmisibles. Dados sus costos y prevalencia, dichas enfermedades crónicas no transmisibles resultan primordiales desde un enfoque de gestión del riesgo en salud pública, siendo, quizá, su gravedad mayor durante la pandemia generada por el SARS CoV-2. Asimismo, se especula que la población confinada pudo llegar a consumir más comida chatarra durante la pandemia del COVID-19 en comparación con otros períodos, además, porque en aquellos con enfermedades crónicas no transmisibles, el confinamiento obligado se asocia con mayor sedentarismo y con un menor número de controles médicos regulares, asuntos que se han reportado previamente. La promulgación de la ley de comida chatarra no va a cambiar los hábitos de alimentación de los colombianos "de la noche a la mañana" y, por esto, se necesita con urgencia implementar procesos de educación y sensibilización frente a los efectos adversos de los alimentos procesados y ultraprocesados en la salud.

For more than one year and a half, Colombia and the world have been facing the effects caused by the pandemics of SARS CoV-2 with concomitant and aggravating deterioration of multiple public health problems such as noncommunicable diseases. Noncommunicable diseases are frequently associated with poor eating habits and regular consumption of processed and ultra-processed foods, among other important risk factors related to culture, genetics, and sedentarism. In July, 2021, Colombia ratified the Law 2120 that promotes healthy food habits and recreational environments, by forcing food producers to include nutritional advertisement seals on processed food packages, with explanatory guidelines for consumers about calories and nutritional value. This editorial note highlights the importance in Odontology of promoting and implementing this Law through education and sensitization of populations, in order to cope with some of the adverse risk factors of the hypercaloric diet.

A set of principles and practical suggestions for equitable fieldwork in biology.

Field biology is an area of research that involves working directly with living organisms in situ through a practice known as "fieldwork." Conducting fieldwork often requires complex logistical planning within multiregional or multinational teams, interacting with local communities at field sites, and collaborative research led by one or a few of the core team members. However, existing power imbalances stemming from geopolitical history, discrimination, and professional position, among other factors, perpetuate inequities when conducting these research endeavors. After reflecting on our own research programs, we propose four general principles to guide equitable, inclusive, ethical, and safe practices in field biology: be collaborative, be respectful, be legal, and be safe. Although many biologists already structure their field programs around these principles or similar values, executing equitable research practices can prove challenging and requires careful consideration, especially by those in positions with relatively greater privilege. Based on experiences and input from a diverse group of global collaborators, we provide suggestions for action-oriented approaches to make field biology more equitable, with particular attention to how those with greater privilege can contribute. While we acknowledge that not all suggestions will be applicable to every institution or program, we hope that they will generate discussions and provide a baseline for training in proactive, equitable fieldwork practices.

Prevalencia y caracterización del riesgo cardiovascular en una población rural / Prevalence and characterization of cardiovascular risk in a rural population

Resumen Introducción: Las enfermedades cardiovasculares son la primera causa de muerte en el mundo. Su incidencia depende de factores de riesgo, los cuales pueden ser evaluados mediante escalas de riesgo cardiovascular que, de acuerdo con este, permiten establecer estrategias de prevención. Sin embargo, están dirigidas principalmente a áreas urbanas de Colombia donde se ha estudiado la carga de la enfermedad, y muy poco a las áreas rurales. Objetivo: Describir las características clínicas de una población rural que asiste a un programa rural de riesgo cardiovascular. Método: Estudio transversal en 540 participantes de un programa de riesgo cardiovascular de nivel primario. Se obtuvieron los datos sociodemográficos, clínicos y bioquímicos. Se estimó el riesgo cardiovascular mediante la escala de Framingham. Resultados: La hipertensión arterial fue el factor de riesgo de mayor prevalencia entre los participantes (95.5%); de ellos, el 70% presentaba un control adecuado de las cifras de presión arterial. En segundo lugar, se encontró sobrepeso/obesidad, con una proporción mayor en mujeres que en hombres (56.4% vs. 70.7%, p = 0.001). El tabaquismo fue de muy baja prevalencia (0.09%), al igual que las complicaciones en órgano blanco (hombres 8% vs. mujeres 2.2%, p = 0.001). El 75% de la población (n = 409) se estratificó como riesgo bajo de acuerdo con la escala de Framingham. Conclusiones: En esta población, la hipertensión arterial, el sobrepeso/obesidad y la coexistencia de diabetes mellitus tipo 2 tienen una prevalencia similar a la de otras poblaciones rurales y urbanas. El estrato de bajo riesgo cardiovascular agrupa a la mayoría de individuos y el tabaquismo es de muy baja prevalencia.

Abstract Introduction: Cardiovascular diseases are the leading cause of death in the world. Its presentation depends on risk factors, which can be evaluated using cardiovascular risk scores and according to its risk establish preventive strategies. However, these strategies have been mainly addressed to urban areas, where the burden of disease has been studied, and not so much to rural areas of Colombia. Objective: To describe the clinical characteristics of a rural population that attends a rural cardiovascular risk program. Method: It was performed a cross-sectional study in 540 participants in a primary-level cardiovascular risk program. Sociodemographic, clinical, and biochemical data were collected. Cardiovascular risk was estimated using the Framingham score. Results: High blood pressure was the highest risk factor in prevalence among the participants (95.5%), of whom 70% had adequate blood pressure values. Overweight/obesity was the second more prevalent risk factor, with a higher proportion in women respect to men (56.4 vs. 70.7%, p = 0.001). Smoking had a low prevalence (0.09%), as well as target organ dysfunction (men 8% vs. women 2.2%, p = 0.001). The 75% of the population (n = 409) was classified in low risk, according to the Framingham score. Conclusions: In this population hypertension, overweight/obesity and the coexistence of type 2 diabetes mellitus had similar prevalence respect to other rural and urban populations. The lower cardiovascular risk stratum grouped most of the participants and smoking had a very low prevalence.

Military Dogs and Their Soldier Companions: The More-than-human Biopolitics of Leishmaniasis in Conflict-torn Colombia.

Cutaneous leishmaniasis is a vector-borne disease that produces growing skin ulcers. In Colombia, the transmitting phlebotomine sandfly is native to the same jungles that have been the primary theater of war. Although combatants are the most affected by leishmaniasis, military landmine detection dogs are also significantly impacted. This article draws on ethnographic field research with human and canine members of the Colombian military. While their leishmaniasis ulcers constitute a shared expression of violence that makes evident the closeness of the human-dog bond, differences in their state-provided health care reveal the production of shifting species hierarchies. I argue that war scrambles both human-dog affective relationships and biopolitically configured interspecies hierarchies in ways that produce suffering, not just for humans and dogs separately, but also for the bonds they forge together. Building peace through health care demands repairing the ways in which armed violence has rendered the bonds between humans and nonhumans pathological.

Astrocytes as essential time-keepers of the central pacemaker.

Since the early observations made by Santiago Ramon y Cajal more than a century ago till now, astrocytes have gradually gained protagonism as essential partners of neurons in building brain circuits that regulate complex behavior. In mammals, processes such as sleep-wake cycle, locomotor activity, cognition and memory consolidation, homeostatic and hedonic appetite and stress response (among others), are synchronized in 24-h rhythms by the circadian system. In such a way, physiology efficiently anticipates and adapts to daily recurring changes in the environment. The hypothalamic suprachiasmatic nucleus (SCN) is considered the central pacemaker, it has been traditionally described as a nucleus of around 10,000 neurons nearly all GABAergic able to be entrained by light and to convey time information through multiple neuronal and hormonal pathways. Only recently, this neuro-centered view was challenged by breakthrough discoveries implicating astrocytes as essential time-keepers. In the present review, we will describe the current view on the SCN circuit and discuss whether astrocytic functions described in other brain regions and state-of-the-art experimental approaches, could help explaining better those well- and not so well-known features of the central pacemaker.

Case Report: Three Case Reports of Rapidly Progressive Dementias and Narrative Review.

Rapidly progressive dementia (RPD) is a heterogeneous group of diseases characterized by cognitive impairment and other neurological disorders developed in a short span of fewer than 2 years. Currently viewed as new and infrequent entities, most medical personnel have little understanding of it. Nevertheless, they significantly compromise many patients' quality of life. Here, we drive 3 clinical cases that evolve as RPD with different etiologies. Case 1: 70-year-old woman presented to the emergency with neuropsychiatric syndrome for 18 days. The researchers identified inflammatory cerebrospinal fluid (CSF), protein 14-3-3-positive T-tau protein, MRI: T2 and FLAIR hyperintensities in bilateral caudate nuclei with diffusion restriction, EEG shows a generalized periodic pattern with triphasic wave morphology. Case 2: 29-year-old man with cognitive impairment and faciobrachial dystonia seizure. The diagnosis was confirmed by achieving elevated antibodies against voltage-gated potassium channels. Case 3: A 49-year-old woman with encephalopathy and myoclonic seizures; EEG and MRI showed subtle changes. The patient also had a normal CSF but a positive CBA serologic NMDA-R antibody test. We described fundamental aspects of RPD to allow made differential diagnoses in patients with cognitive impairment and encephalopathy. Establishing an early and accurate diagnosis can benefit patients with RPD etiologies that are treatable and even reversible, decreasing in morbidity and mortality.

Notch1 and Galectin-3 Modulate Cortical Reactive Astrocyte Response After Brain Injury.

After a brain lesion, highly specialized cortical astrocytes react, supporting the closure or replacement of the damaged tissue, but fail to regulate neural plasticity. Growing evidence indicates that repair response leads astrocytes to reprogram, acquiring a partially restricted regenerative phenotype in vivo and neural stem cells (NSC) hallmarks in vitro. However, the molecular factors involved in astrocyte reactivity, the reparative response, and their relation to adult neurogenesis are poorly understood and remain an area of intense investigation in regenerative medicine. In this context, we addressed the role of Notch1 signaling and the effect of Galectin-3 (Gal3) as underlying molecular candidates involved in cortical astrocyte response to injury. Notch signaling is part of a specific neurogenic microenvironment that maintains NSC and neural progenitors, and Gal3 has a preferential spatial distribution across the cortex and has a central role in the proliferative capacity of reactive astrocytes. We report that in vitro scratch-reactivated cortical astrocytes from C57Bl/6J neonatal mice present nuclear Notch1 intracellular domain (NICD1), indicating Notch1 activation. Colocalization analysis revealed a subpopulation of reactive astrocytes at the lesion border with colocalized NICD1/Jagged1 complexes compared with astrocytes located far from the border. Moreover, we found that Gal3 increased intracellularly, in contrast to its extracellular localization in non-reactive astrocytes, and NICD1/Gal3 pattern distribution shifted from diffuse to vesicular upon astrocyte reactivation. In vitro, Gal3-/- reactive astrocytes showed abolished Notch1 signaling at the lesion core. Notch1 receptor, its ligands (Jagged1 and Delta-like1), and Hes5 target gene were upregulated in C57Bl/6J reactive astrocytes, but not in Gal3-/- reactive astrocytes. Finally, we report that Gal3-/- mice submitted to a traumatic brain injury model in the somatosensory cortex presented a disrupted response characterized by the reduced number of GFAP reactive astrocytes, with smaller cell body perimeter and decreased NICD1 presence at the lesion core. These results suggest that Gal3 might be essential to the proper activation of Notch signaling, facilitating the cleavage of Notch1 and nuclear translocation of NICD1 into the nucleus of reactive cortical astrocytes. Additionally, we hypothesize that reactive astrocyte response could be dependent on Notch1/Jagged1-Hes5 signaling activation following brain injury.

Neuroprotective effect of heparin Trisulfated disaccharide on ischemic stroke.

Cells undergoing hypoxia experience intense cytoplasmic calcium (Ca2+) overload. High concentrations of intracellular calcium ([Ca2+]i) can trigger cell death in the neural tissue, a hallmark of stroke. Neural Ca2+ homeostasis involves regulation by the Na+/Ca2+ exchanger (NCX). Previous data published by our group showed that a product of the enzymatic depolymerization of heparin by heparinase, the unsaturated trisulfated disaccharide (TD; ΔU, 2S-GlcNS, 6S), can accelerate Na+/Ca2+ exchange via NCX, in hepatocytes and aorta vascular smooth muscle cells. Thus, the objective of this work was to verify whether TD could act as a neuroprotective agent able to prevent neuronal cell death by reducing [Ca2+]i. Pretreatment of N2a cells with TD reduced [Ca2+]i rise induced by thapsigargin and increased cell viability under [Ca2+]I overload conditions and in hypoxia. Using a murine model of stroke, we observed that pretreatment with TD decreased cerebral infarct volume and cell death. However, when mice received KB-R7943, an NCX blocker, the neuroprotective effect of TD was abolished, strongly suggesting that this neuroprotection requires a functional NCX to happen. Thus, we propose TD-NCX as a new therapeutic axis for the prevention of neuronal death induced by [Ca2+]i overload.