Preparative Fractionation of Brazilian Red Propolis Extract Using Step-Gradient Counter-Current Chromatography.

Propolis is a resinous bee product with a very complex composition, which is dependent upon the plant sources that bees visit. Due to the promising antimicrobial activities of red Brazilian propolis, it is paramount to identify the compounds responsible for it, which, in most of the cases, are not commercially available. The aim of this study was to develop a quick and clean preparative-scale methodology for preparing fractions of red propolis directly from a complex crude ethanol extract by combining the extractive capacity of counter-current chromatography (CCC) with preparative HPLC. The CCC method development included step gradient elution for the removal of waxes (which can bind to and block HPLC columns), sample injection in a single solvent to improve stationary phase stability, and a change in the mobile phase flow pattern, resulting in the loading of 2.5 g of the Brazilian red propolis crude extract on a 912.5 mL Midi CCC column. Three compounds were subsequently isolated from the concentrated fractions by preparative HPLC and identified by NMR and high-resolution MS: red pigment, retusapurpurin A; the isoflavan 3(R)-7-O-methylvestitol; and the prenylated benzophenone isomers xanthochymol/isoxanthochymol. These compounds are markers of red propolis that contribute to its therapeutic properties, and the amount isolated allows for further biological activities testing and for their use as chromatographic standards.

Impact of quality and transparency in scientific writing on the reduction of animal usage in experimental protocols: a review based in pertinent literature.

The irreproducibility in scientific research has become a critical issue. Despite the essential role of rigorous methodology in constructing a scientific article, more than half of publications, on average, are considered non-reproducible. The implications of this irreproducibility extend to reliability problems, hindering progress in technological production and resulting in substantial financial losses. In the context of laboratory animal research, this work emphasizes the importance of choosing an appropriate experimental model within the 3R's principle (Refine, Reduce, Replace). This study specifically addresses a deficiency in data specification in scientific articles, revealing inadequacies in the description of crucial details, such as environmental conditions, diet, and experimental procedures. For this purpose, 124 articles from journals with relevant impact factors were analyzed, conducting a survey of data considered important for the reproducibility of studies. Important flaws in the presentation of data were identified in most of the articles evaluated. The results of this study highlight the need to improve the description of essential information, standardizing studies, and ensuring the reproducibility of experiments in areas such as metabolism, immunity, hormones, stress, among others, to enhance the reliability and reproduction of experimental results, aligning with international guidelines such as ARRIVE and PREPARE.

Gene Expression of CSF3R/CD114 Is Associated with Poorer Patient Survival in Glioma.

Gliomas comprise most cases of central nervous system (CNS) tumors. Gliomas afflict both adults and children, and glioblastoma (GBM) in adults represents the clinically most important type of malignant brain cancer, with a very poor prognosis. The cell surface glycoprotein CD114, which is encoded by the CSF3R gene, acts as the receptor for the granulocyte colony stimulating factor (GCSF), and is thus also called GCSFR or CSFR. CD114 is a marker of cancer stem cells (CSCs), and its expression has been reported in several cancer types. In addition, CD114 may represent one among various cases where brain tumors hijack molecular mechanisms involved in neuronal survival and synaptic plasticity. Here, we describe CSF3R mRNA expression in human gliomas and their association with patient prognosis as assessed by overall survival (OS). We found that the levels of CSF3R/CD114 transcripts are higher in a few different types of gliomas, namely astrocytoma, pilocytic astrocytoma, and GBM, in comparison to non-tumoral neural tissue. We also observed that higher expression of CSF3R/CD114 in gliomas is associated with poorer outcome as measured by a shorter OS. Our findings provide early evidence suggesting that CSF3R/CD114 shows a potential role as a prognosis marker of OS in patients with GBM.

Antineoplastic effects of pharmacological inhibitors of aurora kinases in CSF3RT618I-driven cells.

Myeloproliferative neoplasms (MPN) are consolidated as a relevant group of diseases derived from the malfunction of the hematopoiesis process and have as a particular attribute the increased proliferation of myeloid lineage. Among these, chronic neutrophilic leukemia (CNL) is distinguished, caused by the T618I mutation of the CSF3R gene, a trait that generates ligand-independent receptor activation and downstream JAK2/STAT signaling. Previous studies reported that mutations in BCR::ABL1 and JAK2V617F increased the expression of the aurora kinase A (AURKA) and B (AURKB) in Ba/F3 cells and their pharmacological inhibition displays antineoplastic effects in human BCR::ABL1 and JAK2V617F positive cells. Delimiting the current scenario, aspects related to the AURKA and AURKB as a potential target in CSF3RT618I-driven models is little known. In the present study, the cellular and molecular effects of pharmacological inhibitors of aurora kinases, such as aurora A inhibitor I, AZD1152-HQPA, and reversine, were evaluated in Ba/F3 expressing the CSF3RT618I mutation. AZD1152-HQPA and reversine demonstrated antineoplastic potential, causing a decrease in cell viability, clonogenicity, and proliferative capacity. At molecular levels, all inhibitors reduced histone H3 phosphorylation, aurora A inhibitor I and reversine reduced STAT5 phosphorylation, and AZD1152-HQPA and reversine induced PARP1 cleavage and γH2AX expression. Reversine more efficiently modulated genes associated with cell cycle and apoptosis compared to other drugs. In summary, our findings shed new insights into the use of AURKB inhibitors in the context of CNL.

Effects on cell cycle progression and cytoskeleton organization of five Bothrops spp. venoms in cell culture-based assays.

Snake envenomation is a neglected tropical disease. In Brazil, the Bothrops genus is responsible for about 86% of snakebite accidents. Despite extensive evidence of the cytotoxicity of snake venoms, the cellular and molecular mechanisms involved are not fully understood, especially regarding the effects on cell cycle progression and cytoskeleton organization. Traditionally, the effectiveness and quality control tests of venoms and antivenoms are assessed by in vivo assays. Despite this, there is a rising effort to develop surrogate in vitro models according to the 3R principle (Replacement, Reduction, and Refinement). In this study, we treated rat liver cells (BRL-3A) with venoms from five Bothrops species (B. jararaca, B. jararacussu, B. moojeni, B. alternatus, and B. neuwiedi) and analyzed cell viability and IC50 by MTT assay, cell cycle phases distribution by flow cytometry, and morphology and cytoskeleton alterations by immunofluorescence. In addition, we evaluated the correlation between IC50 and the enzymatic and biological activities of each venom. Our results indicated that Bothrops spp. venoms decreased the cell viability of rat liver BRL-3A cells. The rank order of potency was B. jararacussu > B. moojeni > B. alternatus > B. jararaca > B. neuwiedi. The mechanisms of cytotoxicity were related to microtubules and actin network disruption, but not to cell cycle arrest. No clear correlation was found between the IC50 and retrieved literature data of in vitro enzymatic and in vivo biological activities. This work contributed to understanding cellular and molecular mechanisms underlying the Bothrops spp. venom cytotoxicity, which can help to improve envenomation treatment, as well as disclose potential therapeutic properties of snake venoms.

Preliminary Study on Artificial versus Animal-Based Feeding Systems for Amblyomma Ticks (Acari: Ixodidae).

Hard ticks pose a threat to animal and human health. Active life stages need to feed on a vertebrate host in order to complete their life cycle. To study processes such as tick-pathogen interactions or drug efficacy and pharmacokinetics, it is necessary to maintain tick colonies under defined laboratory conditions, typically using laboratory animals. The aim of this study was to test a membrane-based artificial feeding system (AFS) applicable for Amblyomma ticks using Amblyomma tonelliae as a biological model. Adult ticks from a laboratory colony were fed in a membrane-based AFS. For comparison, other A. tonelliae adults were fed on calf and rabbit. The proportions of attached (AFS: 76%; calf/rabbit: 100%) and engorged females (AFS: 47.4%; calf/rabbit: 100%) in the AFS were significantly lower compared to animal-based feeding (p = 0.0265). The engorgement weight of in vitro fed ticks (x¯ = 658 mg; SD ± 259.80) did not significantly differ from that of ticks fed on animals (p = 0.3272, respectively 0.0947). The proportion of females that oviposited was 100% for all three feeding methods. However, the incubation period of eggs (x¯ = 54 days; SD ± 7) was longer in the AFS compared to conventional animal-based feeding (p = 0.0014); x¯ = 45 days; SD ± 2 in the rabbit and (p = 0.0144). x¯ = 48 days; SD ± 2 in the calf). Egg cluster hatching (x¯ = 41%; SD ± 44.82) was lower in the AFS than in the other feeding methods (rabbit: x¯ = 74%; SD ± 20; p = 0.0529; calf: x¯ = 81%; SD ± 22; p = 0.0256). Although the attachment, development, and the hatching of AFS ticks were below those from animal-based feeding, the method may be useful in future experiments. Nevertheless, further experiments with a higher number of tick specimens (including immature life stages) and different attractant stimuli are required to confirm the preliminary results of this study and to evaluate the applicability of AFS for Amblyomma ticks as an alternative to animal-based feeding methods.

Reemplazar ideas, reducir equívocos y refinar argumentos: una reinterpretación de las 3R de la experimentación animal

Propósito/Contexto. En el presente trabajo se llevará a cabo una reinterpretación de las tres erres (3R) propuestas por William Russell y Rex Burch (reemplazo, reducción y refinamiento), con el objetivo de ampliar su alcance y mejorar las prácticas de experimentación con animales no humanos. Metodología/Enfoque. Se revisará el sentido que le dieron Russell y Burch a las 3R y se evaluará el modo en que cada una de ellas podría redefinirse o complementarse a la luz de las prácticas científicas, las posibilidades técnicas y los conocimientos bioéticos actuales vinculados al uso de animales en investigación. Resultados/Hallazgos. El artículo mostrará que 1) no solo habrían de reemplazarse animales, sino también las ideas equívocas que tenemos, tanto sobre ellos, como sobre la importancia de la educación bioética en la formación científica, 2) que la reducción, además de referirse al número de sujetos utilizados en cada experimento, debería servir para acabar con investigaciones innecesarias, repetitivas y superfluas, así como con algunos persistentes equívocos sobre el modo de operar de la ciencia y 3) que el refinamiento tendría que salir del espacio experimental para extenderse al modo en que pensamos sobre ética animal en el ámbito de la investigación. Discusión/Conclusiones/Contribuciones. El trabajo da cuenta de la importancia que tiene la incorporación del conocimiento bioético contemporáneo en las prácticas de experimentación con animales para mejorar el carácter reflexivo y ético de la ciencia.

Purpose/Background. In the present work, a reinterpretation of the 3Rs (3Rs) proposed by William Russell and Rex Burch (Replacement, Reduction and Refinement) will be carried out with the aim of broadening its scope and improving nonhuman animal experimentation practices. Methodology/Approach. The meaning given by Russell and Burch to the 3Rs will be reviewed and the way in which each of them could be redefined or complemented in the light of current scientific practices, technical possibilities and bioethical knowledge related to the use of animals in research will be evaluated. Results/Findings. The article will show that 1) not only animals should be replaced, but also the misconceptions we have, both about them and about the importance of bioethics education in scientific training, 2) that the reduction, in addition to the number of subjects used in each experiment, should serve to end unnecessary, repetitive and superfluous research, as well as some persistent misconceptions about the way science operates, and 3) that refinement should go beyond the experimental space to extend to the way we think about animal ethics in the research setting. Discussion/Conclusions/Contributions. The paper reports on the importance of incorporating contemporary bioethical knowledge into animal experimentation practices to enhance the reflexive and ethical character of science.

Objetivo/Contexto. Neste documento, uma reinterpretação dos 3Rs (3Rs) propostos por William Russell e Rex Burch (Substituição, Redução e Refinamento) será realizada com o objetivo de ampliar seu escopo e melhorar as práticas não-humanas de testes em animais. Metodologia/ Abordagem. Revisaremos o significado dado por Russell e Burch aos 3Rs e avaliaremos como cada um deles poderia ser redefinido ou complementado à luz das práticas científicas atuais, possibilidades técnicas e conhecimentos bioéticos relacionados ao uso de animais na pesquisa. Resultados/Descobertas. O artigo mostrará que 1) não somente os animais devem ser substituídos, mas também conceitos errôneos sobre eles e a importância da educação bioética no treinamento científico, 2) que a redução, além do número de sujeitos utilizados em cada experimento, deve servir para eliminar pesquisas desnecessárias, repetitivas e supérfluas, assim como alguns conceitos errôneos persistentes sobre a maneira como a ciência funciona, e 3) que o refinamento deve se estender além do espaço experimental para a maneira como pensamos sobre a ética animal na pesquisa. Discussão/Conclusões/Contribuições. O artigo explica a importância de incorporar o conhecimento bioético contemporâneo nas práticas de experimentação animal para realçar o caráter reflexivo e ético da ciência.

Heterogeneity of the endoplasmic reticulum Ca2+ store determines colocalization with mitochondria.

Contact sites between the endoplasmic reticulum (ER) and mitochondria play a pivotal role in cell signaling, and the interaction between these organelles is dynamic and finely regulated. We have studied the role of ER Ca2+ concentration ([Ca2+]ER) in modulating this association in HeLa and HEK293 cells and human fibroblasts. According to Manders' coefficient, ER-mitochondria colocalization varied depending on the ER marker; it was the highest with ER-Tracker and the lowest with ER Ca2+ indicators (Mag-Fluo-4, erGAP3, and G-CEPIA1er) in both HeLa cells and human fibroblasts. Only GEM-CEPIA1er displayed a high colocalization with elongated mitochondria in HeLa cells, this ER Ca2+ indicator reveals low Ca2+ regions because this ion quenches its fluorescence. On the contrary, the typical rounded and fragmented mitochondria of HEK293 cells colocalized with Mag-Fluo-4 and, to a lesser extent, with GEM-CEPIA1er. The ablation of the three IP3R isoforms in HEK293 cells increased mitochondria-GEM-CEPIA1er colocalization. This pattern of colocalization was inversely correlated with the rate of ER Ca2+ leak evoked by thapsigargin (Tg). Moreover, Tg and Histamine in the absence of external Ca2+ increased mitochondria-ER colocalization. On the contrary, in the presence of external Ca2+, both Bafilomycin A1 and Tg reduced the mitochondria-ER interaction. Notably, knocking down MCU decreased mitochondria-ER colocalization. Overall, our data suggest that the [Ca2+] is not homogenous within the ER lumen and that mitochondria-ER interaction is modulated by the ER Ca2+ leak and the [Ca2+]i.

Multitargeting approaches to cognitive impairment: Synthesis of aryl-alkylpiperazines and assessment at cholinesterases, histamine H3 and dopamine D3 receptors.

Multitargeting ligands on enzymes and receptors may generate a profile for a potential treatment of cognitive impairment. Considering this, a set of 21 substituted aryl-alkyl-piperazines were designed, prepared and tested for their binding affinities at histamine H3 and dopamine D3 receptors (H3R and D3R, respectively) as well as acetyl- and butyrylcholinesterases (AChE/BChE) as potentially synergistic profile. Initial screening of the compounds at H3R and D3R was done at 1 or 10 µM and 100 µM at AChE and BChE assays. The most promising compounds were then evaluated in full concentration-response curves to estimate the Ki and IC50 values. Results showed that several compounds were ligands at H3R (n = 10), D3R (n = 6), AChE (n = 3), and BChE (n = 9). Compounds LINS05006 (Ki H3R 2.8 µM; D3R 0.7 µM; IC50 BChE 26.3 µM) and LINS05015 (Ki H3R 1.1 µM; D3R 3.1 µM; IC50 AChE 97.8 µM; BChE 43.7 µM) are highlighted since presented affinity in three different. These results suggest that methylpiperazine moiety led to balanced activity at all three classes of targets, and longer linker provided the best affinities. These compounds presented high ligand efficiency values (LE > 0.3) and may have adequate pharmacokinetic profile as suggested by calculated physicochemical properties.

PIK3R2 predicts poor outcomes for patients with melanoma and contributes to the malignant progression via PI3K/AKT/NF-κB axis.

BACKGROUND: Melanoma is an aggressive form of skin cancer worldwide. Phosphoinositide-3-kinase regulatory subunit 2 (PIK3R2) exerts carcinogenic roles in various tumors. So far, the function and mechanism of PIK3R2 in melanoma are not been fully clarified. OBJECTIVE: We aimed to clarify the role of PIK3R2 in melanoma. METHODS: PIK3R2 expressions in melanoma clinical tissues and melanoma cells were measured using quantitative real-time PCR and Western blot. In addition, PIK3R2 expressions in different tumor stages of melanoma were determined by immunohistochemistry assay. Meanwhile, PIK3R2 function was evaluated using loss or gain-of-function assays, Cell Counting Kit-8 assay, flow cytometry, and Transwell analysis. Furthermore, PIK3R2 mechanism in melanoma was assessed by a series of rescue experiments. RESULTS: PIK3R2 was highly expressed in melanoma tissues and cells, and PIK3R2 expressions were the highest in Stage IV. Functionally, PIK3R2 knockdown repressed melanoma cell proliferation, invasion, epithelial-mesenchymal transition, and facilitated cell apoptosis. Also, PIK3R2 overexpression produced an opposite trend. Mechanistically, PIK3R2 facilitated melanoma progression by activating PI3K/AKT/NF-κB pathway. Furthermore, PIK3R2 knockdown restrained the melanoma tumor growth in vivo. CONCLUSIONS: PIK3R2 aggravated melanoma by activating PI3K/AKT/NF-κB pathway, prompting that PIK3R2 might be a therapeutic target for melanoma.

Effects on cell cycle progression and cytoskeleton organization of five Bothrops spp. venoms in cell culture-based assays

Snake envenomation is a neglected tropical disease. In Brazil, the Bothrops genus is responsible for about 86% of snakebite accidents. Despite extensive evidence of the cytotoxicity of snake venoms, the cellular and molecular mechanisms involved are not fully understood, especially regarding the effects on cell cycle progression and cytoskeleton organization. Traditionally, the effectiveness and quality control tests of venoms and antivenoms are assessed by in vivo assays. Despite this, there is a rising effort to develop surrogate in vitro models according to the 3R principle (Replacement, Reduction, and Refinement). In this study, we treated rat liver cells (BRL-3A) with venoms from five Bothrops species (B. jararaca, B. jararacussu, B. moojeni, B. alternatus, and B. neuwiedi) and analyzed cell viability and IC50 by MTT assay, cell cycle phases distribution by flow cytometry, and morphology and cytoskeleton alterations by immunofluorescence. In addition, we evaluated the correlation between IC50 and the enzymatic and biological activities of each venom. Our results indicated that Bothrops spp. venoms decreased the cell viability of rat liver BRL-3A cells. The rank order of potency was B. jararacussu > B. moojeni > B. alternatus > B. jararaca > B. neuwiedi. The mechanisms of cytotoxicity were related to microtubules and actin network disruption, but not to cell cycle arrest. No clear correlation was found between the IC50 and retrieved literature data of in vitro enzymatic and in vivo biological activities. This work contributed to understanding cellular and molecular mechanisms underlying the Bothrops spp. venom cytotoxicity, which can help to improve envenomation treatment, as well as disclose potential therapeutic properties of snake venoms.

Câncer de pele não melanoma: revisão integrativa / Non-melanoma skin cancer: an integrative review

Introdução: O câncer de pele não melanoma compeende grupo de neoplasias com alta incidência na população mundial. É dividido em carcinoma basocelular e de células escamosas. Por ser de grande prevalência, entender o processo de oncogênese e a relação com íons, proteínas e receptores celulares no câncer de pele não melanoma pode contribuir para que novas terapêuticas sejam avaliadas. Objetivo: Entender o processo da oncogênese dos tumores de pele não melanomas e sua relação com a imunolocalização do IP3R. Métodos: Revisão integrativa da literatura com síntese de evidências. A base de dados foi o PubMed; a estratégia de busca: "carcinoma espinocelular, AND/ OR carcinoma basocelular, AND/OR IP3R, AND/OR imunoistoquímica". Foram considerados para revisão os trabalhos publicados entre 2018 e 2023. Foram incluídos 40 trabalhos, integralmente lidos e resumidos. Resultados: Câncer de pele não melanoma são os tumores malignos mais comuns em todo o mundo, sendo 75-80% o carcinoma basocelular, e até 25% o de células escamosas. As interações moleculares de forma geral, envolvem grande participação de moléculas supressoras tumorais, assim como de procto-oncogenes. Além disso, canais iônicos voltagem dependente controlam o fluxo citosólico de íons, dentre eles o cálcio. O IP3R (receptor do fosfatidil inositol-3) permite a saída de cálcio do retículo endoplasmático para que seja utilizado pela célula para atividades fisiológias como proliferação, angiogênese, motilidade e capacidade de invasão. Conclusão: O IP3R, pelas características de expressão imunoistoquímica, parece estar relacionado também, à fisiopatologia do câncer de pele não melanoma.

Introduction: Non-melanoma skin cancer comprises a group of neoplasms with a high incidence in the world population. It is divided into basal cell carcinoma and squamous cell carcinoma. As it is highly prevalent, understanding the process of oncogenesis and the relationship with ions, proteins and cellular receptors in nonmelanoma skin cancer can contribute to the evaluation of new therapies. Objective: To understand the oncogenesis process of non-melanoma skin tumors and its relationship with the immunolocalization of IP3R. Methods: Integrative literature review with evidence synthesis. The database was PubMed; the search strategy: "squamous cell carcinoma, AND/OR basal cell carcinoma, AND/OR IP3R, AND/OR immunohistochemistry". Works published between 2018 and 2023 were considered for review; 40 works were included, fully read and summarized. Results: Non-melanoma skin cancer is the most common malignant tumor worldwide, with 75-80% being basal cell carcinoma, and up to 25% being cell carcinoma. Molecular interactions in general involve a large participation of tumor suppressor molecules, as well as procto-oncogenes. Furthermore, voltage-dependent ion channels control the cytosolic flow of ions, including calcium. The IP3R (phosphatidyl inositol-3 receptor) allows the exit of calcium from the endoplasmic reticulum so that it can be used by the cell for physiological activities such as proliferation, angiogenesis, motility and invasion capacity. Conclusion: The IP3R, due to its immunohistochemical expression characteristics, appears may also be related to the pathophysiology of nonmelanoma skin cancer.

Generic Pheromones Identified from Northern Hemisphere Cerambycidae (Coleoptera) Are Attractive to Native Longhorn Beetles from Central-Southern Chile.

We conducted field bioassays with several known cerambycid pheromones in two zones of central-southern Chile: (1) Las Trancas (Ñuble region) and Coñaripe (Los Rios region) (Study 1) and (2) Rucamanque and Maquehue (La Araucania region) (Study 2). Up to eight compounds were tested individually, including 3-hydroxy-2-hexanone, (2R*,3S*)- and (2R*,3R*)-2,3-hexanediol, fuscumol, fuscumol acetate, monochamol, 2-methylbutanol, and geranylacetone. Compounds were loaded in plastic sachets placed in either multiple funnel or cross-vane panel traps hung in trees in a randomized block design (n = 3 or 4). The number of treatments and bioassay periods varied depending on the study. A total of 578 specimens belonging to 11 native species were collected, with the three captured in the highest numbers being Eryphus laetus (292 specimens), Calydon submetallicum (n = 234), and Chenoderus testaceus (n = 20). The three species are of economic importance: E. laetus is considered a minor pest in apple orchards, and the other two species infest Nothophagus hosts, including some timber species. Traps baited with 3-hydroxy-2-hexanone collected significant numbers of both sexes of the two most abundant species, and this compound was the only treatment that attracted C. submetallicum. (2R*,3R*)- and (2R*,3S*)-2,3-Hexanediols were also significantly attractive to E. laetus. Our results suggested that 3-hydroxy-2-hexanone and 2,3-hexanediols, which are known pheromone components of cerambycid species worldwide, are also likely to be conserved aggregation pheromone components among some species in western South America.

Substituted Purines as High-Affinity Histamine H3 Receptor Ligands.

Continuing with our program to obtain new histamine H3 receptor (H3R) ligands, in this work we present the synthesis, H3R affinity and in silico studies of a series of eight new synthetically accessible purine derivatives. These compounds are designed from the isosteric replacement of the scaffold presented in our previous ligand, pyrrolo[2,3-d]pyrimidine ring, by a purine core. This design also considers maintaining the fragment of bipiperidine at C-4 and aromatic rings with electron-withdrawing groups at N-9, as these fragments are part of the proposed pharmacophore. The in vitro screening results show that two purine derivatives, 3d and 3h, elicit high affinities to the H3R (Ki values of 2.91 and 5.51 nM, respectively). Both compounds are more potent than the reference drug pitolisant (Ki 6.09 nM) and show low toxicity with in vitro models (IC50 > 30 µM on HEK-293, SH-SY5Y and HepG2 cell lines). Subsequently, binding modes of these ligands are obtained using a model of H3R by docking and molecular dynamics studies, thus determining the importance of the purine ring in enhancing affinity due to the hydrogen bonding of Tyr374 to the N-7 of this heterocycle. Finally, in silico ADME properties are predicted, which indicate a promising future for these molecules in terms of their physical−chemical properties, absorption, oral bioavailability and penetration in the CNS.

A metabotropic glutamate receptor 3 (mGlu3R) isoform playing neurodegenerative roles in astrocytes is prematurely up-regulated in an Alzheimer's model.

Subtype 3 metabotropic glutamate receptor (mGlu3R) displays a broad range of neuroprotective effects. We previously demonstrated that mGlu3R activation in astrocytes protects hippocampal neurons from Aß neurotoxicity through stimulation of both neurotrophin release and Aß uptake. Alternative-spliced variants of mGlu3R were found in human brains. The most prevalent variant, mGlu3Δ4, lacks exon 4 encoding the transmembrane domain and can inhibit ligand binding to mGlu3R. To date, neither its role in neurodegenerative disorders nor its endogenous expression in CNS cells has been addressed. The present paper describes for the first time an association between altered hippocampal expression of mGlu3Δ4 and Alzheimer's disease (AD) in the preclinical murine model PDAPP-J20, as well as a deleterious effect of mGlu3Δ4 in astrocytes. As assessed by western blot, hippocampal mGlu3R levels progressively decreased with age in PDAPP-J20 mice. On the contrary, mGlu3Δ4 levels were drastically increased with aging in nontransgenic mice, but prematurely over-expressed in 5-month-old PDAPP-J20-derived hippocampi, prior to massive senile plaque deposition. Also, we found that mGlu3Δ4 co-precipitated with mGlu3R mainly in 5-month-old PDAPP-J20 mice. We further showed by western blot that primary cultured astrocytes and neurons expressed mGlu3Δ4, whose levels were reduced by Aß, thereby discouraging a causal effect of Aß on mGlu3Δ4 induction. However, heterologous expression of mGlu3Δ4 in astrocytes induced cell death, inhibited mGlu3R expression, and prevented mGlu3R-dependent Aß glial uptake. Indeed, mGlu3Δ4 promoted neurodegeneration in neuron-glia co-cultures. These results provide evidence of an inhibitory role of mGlu3Δ4 in mGlu3R-mediated glial neuroprotective pathways, which may lie behind AD onset.

The endocannabinoid system in zebrafish and its potential to study the effects of Cannabis in humans.

Zebrafish is considered an unprecedented animal model in drug discovery. A review of the literature presents highlights and elucidates the biological effects of chemical components found in Cannabis sativa. Particular attention is paid to endocannabinoid system (eCB) and its main receptors (CB1 and CB2). The zebrafish model is a promising one for the study of cannabinoids because of the many similarities to the human system. Despite the recent advances on the eCB system, there is still the need to elucidate some of the interactions and, thus, the zebrafish model can be used for that purpose as it respects the 3Rs concept and reduced time and costs. In view of the relevance of cannabinoids in the treatment and prevention of diseases, as well as the importance of the zebrafish animal model in elucidating the biological effects of new drugs, the aim of this study was to bring to light information on the use of the zebrafish animal model in testing C. sativa-based medicines.

SHORT syndrome in an adult Brazilian patient.

We report an individual from Brazil with SHORT syndrome. The term SHORT stands for its common characteristics: short stature (S), hyperextensibility of joints, and/or inguinal hernia (H), ocular depression (O), Rieger anomaly (R), and teething delay (T). In addition to most of the clinical signs previously described in SHORT syndrome, the patient presented here also shows microcephaly and intellectual disability. Diagnosis was confirmed by exome sequencing revealing a novel heterozygous variant c.1456G>A (p.Ala486Thr) at PIK3R1. Human recombinant growth hormone (r-hGH) therapy was administered prior to diagnosis; however, the use of r-hGH may have had a role in anticipating and worsening the glucose metabolic profile in the patient, as previously described. This article contributes to providing a better understanding of the SHORT syndrome genotype and its correlation with the phenotype, by comparing with it other reported cases.

Análise de viabilidade celular em linhagem RPE - 1 para teste de toxicidade do veneno de Bothrops jararaca (Wied - Neuwied, 1824)

Snake envenomation is classified by the WHO as a neglected tropical disease. Since 2019, due to the 138,000 deaths/year, it has become a target of the organization's plan to reduce deaths and disability. In Brazil, Bothrops jararaca is responsible for 86.8% of accidents, being the subject of many studies to better understand the mechanisms of action of its venom. Toxicity testing commonly involves the use of animal models. Created in 1959, the 3 R’s principle aims to reduce, refine and replace the use of animals with alternative methods with equivalent results. Based on this premise, the objective of this work was to evaluate the toxicity of B. jararaca venom in cell culture as an alternative or complement to toxicity tests performed on animals, aiming at a greater alignment with the 3 R’s principle. RPE-1 cells (15.000 cells/well) were treated with B. jararaca venom between 0.1 μg/mL to 200 μg/mL for 24 h, cell viability and IC50 were calculated by MTT colorimetric assay. Five initial trials established optimal venom concentrations between 10 μg/mL and 200 μg/mL. The results indicated a dose-dependent decrease in cell viability, with a significant drop from 50 μg/mL, presenting viability of 70% and decreasing up to 7% at 200 μg/m. The IC50 calculation resulted in 75.20 μg/mL In conclusion, the work showed that the use of cell culture to analyze cell viability through the MTT test represents an effective method for obtaining data on the cytotoxicity of B. jararaca venom, contributing to the development of alternative methods to the use of animals, according to the principle of the 3 R’s.

O envenenamento por serpentes é classificado pela OMS como uma doença tropical negligenciada. Desde 2019, devido às 138.000 mortes/ano, tornou-se alvo do plano da organização para redução de mortes e invalidez. No Brasil, a espécie Bothrops jararaca é responsável por 86,8% dos acidentes, sendo alvo de muitos estudos para melhor compreensão dos mecanismos de ação de seu veneno. Testes de toxicidade comumente envolvem o uso de modelos animais. Criado em 1959, o princípio dos 3 R’s visa reduzir, refinar e substituir o uso de animais por métodos alternativos com resultados equivalentes. Partindo dessa premissa, o objetivo deste trabalho foi avaliar a toxicidade do veneno de B. jararaca em cultura celular como alternativa ou complemento aos testes de toxicidade realizados em animais, visando um maior alinhamento com o princípio dos 3 R’s. Células RPE-1 (15.000 células/poço) foram tratadas com veneno de B. jararaca entre 0,1 μg/mL a 200 μg/mL por 24 h, a viabilidade celular e o IC50 foram calculados através do ensaio colorimétrico de MTT. Cinco ensaios iniciais estabeleceram as concentrações ideais do veneno entre 10 μg/mL e 200 μg/mL. Os resultados indicaram uma diminuição dose-dependente de viabilidade celular, com queda significativa a partir de 50 μg/mL, apresentando viabilidade de 70% e decaindo até 7% em 200 μg/m. O cálculo do IC50 resultou em 75,20 μg/mL Em conclusão, o trabalho mostrou que o uso da cultura celular para análise da viabilidade celular através do teste de MTT representa um método eficaz na obtenção de dados sobre citotoxicidade do veneno de B. jararaca, contribuindo para o desenvolvimento de métodos alternativos ao uso de animais, segundo o princípio dos 3 R’s.

The ER-mitochondria Ca2+ signaling in cancer progression: Fueling the monster.

Cancer is a leading cause of death worldwide. All major tumor suppressors and oncogenes are now recognized to have fundamental connections with metabolic pathways. A hallmark feature of cancer cells is a reprogramming of their metabolism even when nutrients are available. Increasing evidence indicates that most cancer cells rely on mitochondrial metabolism to sustain their energetic and biosynthetic demands. Mitochondria are functionally and physically coupled to the endoplasmic reticulum (ER), the major calcium (Ca2+) storage organelle in mammalian cells, through special domains known as mitochondria-ER contact sites (MERCS). In this domain, the release of Ca2+ from the ER is mainly regulated by inositol 1,4,5-trisphosphate (IP3) receptors (IP3Rs), a family of Ca2+ release channels activated by the ligand IP3. IP3R mediated Ca2+ release is transferred to mitochondria through the mitochondrial Ca2+ uniporter (MCU). Once in the mitochondrial matrix, Ca2+ activates several proteins that stimulate mitochondrial performance. The role of IP3R and MCU in cancer, as well as the other proteins that enable the Ca2+ communication between these two organelles is just beginning to be understood. Here, we describe the function of the main players of the ER mitochondrial Ca2+ communication and discuss how this particular signal may contribute to the rise and development of cancer traits.

The nonpharmacological sequence method provides a reliable evaluation of baroreflex sensitivity in fish.

The most commonly used technique to study the barostatic regulation of blood pressure in ectothermic vertebrates consists of determining the heart rate response to pharmacological manipulations of blood pressure, the so-called "Oxford method." Although well established, the Oxford method has some important limitations, such as induction of hypervolemia in small animals and undesired effects of vasoactive drugs on central and peripheral baroreflex components. As an alternative, the sequence method, which consists in the computerized evaluation of naturally-occurring baroreflex adjustments of heart rate without the need for pharmacological administrations, was developed to study baroreflexes. In the present study, we compare this sequence method with the Oxford technique in two teleost species with different life styles, and we assess the optimal software configuration for the employment of the sequence method in fish. Calculation of baroreflex gain through the sequence method was adequate and reliable when the software was configured to search for baroreflex sequences with a minimum length of three cardiac cycles with a delay of one cardiac cycle between fluctuations in mean ventral aortic blood pressure and reflex changes in pulse interval. When properly configured, the sequence and the Oxford methods yielded similar determinations of the baroreflex gain in fish.