The Perceptions of Students and Lecturers on the Use of Animals in Biomedical Science Undergraduate Education in Brazil.

The use of animals in research and education is a controversial topic that has raised extensive debates. Undergraduate students (n = 404) and lecturers (n = 62) from biomedical science schools at the Federal University of Goiás (UFG) in the municipality of Goiânia, Jataí and Catalão, Goiás, Brazil, were asked about their knowledge and opinions on bioethics, the use and importance of animals in education, the replacement of animal use with non-animal alternatives, and the current legislation of the National Council for the Control of Animal Experimentation (CONCEA) that bans animal use in some practical classes within technical and higher education (i.e. Resolution No. 53/2021). Most students and lecturers agreed not only that animal use can contribute to education, but also that it is important to replace this animal use with innovative non-animal alternatives where appropriate. The lecturers emphasised that the replacement of animal models will be possible only with the provision of appropriate training to improve the skills of educators in their use, as well as ensuring reliable access to suitable facilities and materials.

Antiangiogenic and antitumoral activity of LQFM126 prototype against B16F10 melanoma cells.

Inhibition of mouse double minute 2 homolog (MDM2)-p53 interaction and reactivation of p53 signaling have been explored as effective anticancer therapeutic strategy. The potent and specific antitumor activity shown by Nutlins, first class of MDM2-p53 inhibitors discovered, has made these compounds potential antitumor candidates. To this end, we synthesized Nutlin-1 and Nutlin-2 analogs through molecular simplification and selected the compound with the most efficient antitumoral activity. Cytotoxicity of Nutlin-2 analog LQFM126 on B16F10 melanoma cells induced intense cytoplasmic vacuolization, reduction of cell size, chromatin condensation, cytoplasmic degeneration and nuclear fragmentation. LQFM126 antiproliferative effects mediated cell cycle retention in G0/G1 phase and increased the levels of cell cycle regulatory proteins p21 and p27. This Nutlin analog increased mitochondrial membrane potential, activated caspase-8, -9 and -3/7 and reduced VEGF levels in B16F10 cells. Therefore, LQFM126 promoted alterations suggestive of apoptosis, G0/G1 cell cycle arrest and suppression of angiogenesis through modulation of VEGF expression in B16F10 cells. Additionally, LQFM126 was classified as UN GHS category 4 (LD50 > 300-2000 mg/kg), suggesting it has low acute systemic toxicity. LQFM126 can be a promising prototype for anticancer therapy.

Nerve Growth Factor Gene Delivery across the Blood-Brain Barrier to Reduce Beta Amyloid Accumulation in AD Mice.

The therapeutic potential of the nerve growth factor (NGF) gene using brain-targeted liposomal nanoparticles was investigated for the treatment of Alzheimer's disease (AD). We designed brain-targeted gene delivery systems with prolonged systemic circulation and enhanced cellular penetration by conjugating the transferrin (Tf) ligand and the penetratin (Pen) peptide to liposomes via a 1, 2-distearoyl-sn-glycero-3-phosphoethanolamine-poly(ethylene glycol) phospholipid. In vitro characterization studies showed that the nanoparticles had homogeneous particle size and positive zeta potential and were able to protect the plasmid DNA against enzymatic degradation. In vivo brain targeting efficiency of designed liposomes was mimicked using an in vitro triple coculture blood-brain barrier (BBB) model. Liposomal nanoparticles dual-modified with Tf and Pen encasing plasmid NGF efficiently crossed the in vitro BBB model and, subsequently, transfected the primary neuronal cells. Increasing NGF expression in primary neuronal cells following treatment with liposomes increased the levels of the presynaptic marker synaptophysin in vitro. A dose-response study in vivo was performed in order to select the appropriate dose of plasmid NGF to induce significant NGF expression and, consequently, a therapeutic effect. Administration of PenTf-liposomes containing pNGF to amyloid precursor protein (APP)/PS1 mice (aged 3 months) for 4 weeks (one injection per week) significantly decreased (p < 0.05) the levels of toxic soluble and insoluble Aß peptides as compared to those levels in untreated APP/PS1 mice. Additionally, the treatment stimulated cell proliferation and increased the levels of synaptic markers, synaptophysin and PSD-95. These data suggest the therapeutic potential of PenTf-liposome-mediated NGF gene therapy, and this system can be considered a candidate for the treatment of AD.

4-Nerolidylcatechol: apoptosis by mitochondrial mechanisms with reduction in cyclin D1 at G0/G1 stage of the chronic myelogenous K562 cell line.

CONTEXT: 4-Nerolidylcatechol (4-NRC) has showed antitumor potential through apoptosis. However, its apoptotic mechanisms are still unclear, especially in leukemic cells. OBJECTIVES: To evaluate the cytotoxic potential of 4-NRC and its cell death pathways in p53-null K562 leukemic cells. MATERIALS AND METHODS: Cytotoxicity of 4-NRC (4.17-534.5 µM) over 24 h of exposure was evaluated by MTT assay. 4-NRC-induced apoptosis in K562 cells was investigated by phosphatidylserine (PS) externalization, cell cycle, sub-G1, mitochondrial evaluation, cytochrome c, cyclin D1 and intracellular reactive oxygen species (ROS) levels, and caspase activity analysis. RESULTS: IC50 values obtained were 11.40, 27.31, 15.93 and 15.70 µM for lymphocytes, K562, HL-60 and Jurkat cells, respectively. In K562 cells, 4-NRC (27 µM) promoted apoptosis as verified by cellular morphological changes, a significant increase in PS externalization and sub-G1 cells. Moreover, it significantly arrested the cells at the G0/G1 phase due to a reduction in cyclin D1 expression. These effects of 4-NRC also significantly promoted a reduction in mitochondrial activity and membrane depolarization, accumulation of cytosolic cytochrome c and ROS overproduction. Additionally, it triggered an increase in caspases -3/7, -8 and -9 activities. When the cells were pretreated with N-acetyl-l-cysteine ROS scavenger, 4-NRC-induced apoptosis was partially blocked, which suggests that it exerts cytotoxicity though not exclusively through ROS-mediated mechanisms. DISCUSSION AND CONCLUSION: 4-NRC has antileukemic properties, inducing apoptosis mediated by mitochondrial-dependent mechanisms with cyclin D1 inhibition. Given that emerging treatment concepts include novel combinations of well-known agents, 4-NRC could offer a promising alternative for chemotherapeutic combinations to maximize tumour suppression.

Eugenia dysenterica DC. (Myrtaceae) exerts chemopreventive effects against hexavalent chromium-induced damage in vitro and in vivo.

CONTEXT: Eugenia dysenterica DC. (Myrtaceae) has been widely used in the folk medicine and it presents phytochemicals constituents associated to antioxidant properties. OBJECTIVE: The objective of this study was to investigate the protective effects of E. dysenterica leaf hydroalcoholic extract (EDE) in vitro and in vivo using AMJ2-C11 cells and Swiss mice exposed to hexavalent chromium [Cr(VI)], respectively. MATERIALS AND METHODS: AMJ2-C11 cells were pretreated with EDE and exposed to Cr(VI) to evaluate cytotoxicity and the pathways involved in the chemopreventive effects of the extract. Mice were daily pretreated with EDE and then exposed to Cr(VI). Survival analysis, histopathological examination and determination of Cr levels in biological tissues were carried out. RESULTS: In vitro studies showed that pretreatment of the AMJ2-C11 cells with EDE protected against the cytotoxicity and oxidative stress induced by Cr(VI). Consequently, the pretreatment with EDE reduced reactive oxygen species and apoptosis triggered by Cr(VI), probably by a marked antioxidant and chelating activities demonstrated by EDE. Regarding in vivo studies, pretreatment for 10 days with EDE increased survival of the mice exposed to Cr(VI). In addition, EDE prevented liver and kidney pathological damages, in parallel with reduction in chromium levels found in these organs and plasma. EDE also showed a marked antioxidant potential associated with the presence of polyphenols, especially flavonoids and tannins, as confirmed by HPLC-PDA. CONCLUSION: The study showed that EDE protects against Cr(VI)-induced damage in vitro and in vivo supporting further studies for the development of therapeutic products applied to prevent the damage induced by toxic metals, especially Cr(VI).