Netrin G1 Ligand is a new stromal immunomodulator that promotes pancreatic cancer.

Understanding pancreatic cancer biology is fundamental for identifying new targets and for developing more effective therapies. In particular, the contribution of the stromal microenvironment to pancreatic cancer tumorigenesis requires further exploration. Here, we report the stromal roles of the synaptic protein Netrin G1 Ligand (NGL-1) in pancreatic cancer, uncovering its pro-tumor functions in cancer-associated fibroblasts and in immune cells. We observed that the stromal expression of NGL-1 inversely correlated with patients' overall survival. Moreover, germline knockout (KO) mice for NGL-1 presented decreased tumor burden, with a microenvironment that is less supportive of tumor growth. Of note, tumors from NGL-1 KO mice produced less immunosuppressive cytokines and displayed an increased percentage of CD8 + T cells than those from control mice, while preserving the physical structure of the tumor microenvironment. These effects were shown to be mediated by NGL-1 in both immune cells and in the local stroma, in a TGF-ß-dependent manner. While myeloid cells lacking NGL-1 decreased the production of immunosuppressive cytokines, NGL-1 KO T cells showed increased proliferation rates and overall polyfunctionality compared to control T cells. CAFs lacking NGL-1 were less immunosuppressive than controls, with overall decreased production of pro-tumor cytokines and compromised ability to inhibit CD8 + T cells activation. Mechanistically, these CAFs downregulated components of the TGF-ß pathway, AP-1 and NFAT transcription factor families, resulting in a less tumor-supportive phenotype. Finally, targeting NGL-1 genetically or using a functionally antagonistic small peptide phenocopied the effects of chemotherapy, while modulating the immunosuppressive tumor microenvironment (TME), rather than eliminating it. We propose NGL-1 as a new local stroma and immunomodulatory molecule, with pro-tumor roles in pancreatic cancer. Statement of Significance: Here we uncovered the pro-tumor roles of the synaptic protein NGL-1 in the tumor microenvironment of pancreatic cancer, defining a new target that simultaneously modulates tumor cell, fibroblast, and immune cell functions. This study reports a new pathway where NGL-1 controls TGF-ß, AP-1 transcription factor members and NFAT1, modulating the immunosuppressive microenvironment in pancreatic cancer. Our findings highlight NGL-1 as a new stromal immunomodulator in pancreatic cancer.

Rethinking the Roles of Cancer-Associated Fibroblasts in Pancreatic Cancer.

Bearing a dismal 5-year survival rate, pancreatic ductal adenocarcinoma (PDAC) is a challenging disease that features a unique fibroinflammatory tumor microenvironment. As major components of the PDAC tumor microenvironment, cancer-associated fibroblasts are still poorly understood and their contribution to the several hallmarks of PDAC, such as resistance to therapies, immunosuppression, and high incidence of metastasis, is likely underestimated. There have been encouraging advances in the understanding of these fascinating cells, but many controversies remain, leaving the field still actively exploring the full scope of their contributions in PDAC progression. Here we pose several important considerations regarding PDAC cancer-associated fibroblast functions. We posit that transcriptomic analyses be interpreted with caution, when aiming to uncover the functional contributions of these cells. Moreover, we propose that normalizing these functions, rather than eliminating them, will provide the opportunity to enhance therapeutic response. Finally, we propose that cancer-associated fibroblasts should not be studied in isolation, but in conjunction with its extracellular matrix, because their respective functions are coordinated and concordant.

Microarray data analysis of antileukemic action of Cinnamoylated benzaldehyde LQB-461 in Jurkat cell line.

BACKGROUND: Leukemias stand out for being the main type of childhood cancer in the world. Current treatments have strong side effects for patients, and there is still a high rate of development of resistance to multidrug therapy. Previously, our research group developed a structure-activity study with novel synthetic molecules analogous to LQB-278, described as an essential molecule with in vitro antileukemic action. Among these analogs, LQB-461 stood out, presenting more significant antileukemic action compared to its derivative LQB-278, with cytostatic and cytotoxicity effect by apoptosis, inducing caspase-3, and increased sub-G1 phase on cell cycle analysis. METHODS AND RESULTS: Deepening the study of the mechanism of action of LQB-461 in Jurkat cells in vitro, a microarray assay was carried out, which confirmed the importance of the apoptosis pathway in the LQB-461 activity. Through real-time PCR, we validated an increased expression of CDKN1A and BAX genes, essential mediators of the apoptosis intrinsic pathway. Through the extrinsic apoptosis pathway, we found an increased expression of the Fas receptor by flow cytometry, showing the presence of a more sensitive population and another more resistant to death. Considering the importance of autophagy in cellular resistance, it was demonstrated by western blotting that LQB-461 decreased LC-3 protein expression, an autophagic marker. CONCLUSIONS: These results suggest that this synthetic molecule LQB-461 induces cell death by apoptosis in Jurkat cells through intrinsic and extrinsic pathways and inhibits autophagy, overcoming some mechanisms of cell resistance related to this process, which differentiates LQB-461 of other drugs used for the leukemia treatment.

Pulsed low-dose-rate radiation (PLDR) reduces the tumor-promoting responses induced by conventional chemoradiation in pancreatic cancer-associated fibroblasts.

Pancreatic cancer is becoming increasingly deadly, with treatment options limited due to, among others, the complex tumor microenvironment (TME). This short communications study investigates pulsed low-dose-rate radiation (PLDR) as a potential alternative to conventional radiotherapy for pancreatic cancer neoadjuvant treatment. Our ex vivo research demonstrates that PLDR, in combination with chemotherapy, promotes a shift from tumor-promoting to tumor-suppressing properties in a key component of the pancreatic cancer microenvironment we called CAFu (cancer-associated fibroblasts and selfgenerated extracellular matrix functional units). This beneficial effect translates to reduced desmoplasia (fibrous tumor expansion) and suggests PLDR's potential to improve total neoadjuvant therapy effectiveness. To comprehensively assess this functional shift, we developed the HOST-Factor, a single score integrating multiple biomarkers. This tool provides a more accurate picture of CAFu function compared to individual biomarkers and could be valuable for guiding and monitoring future therapeutic strategies. Our findings support the ongoing NCT04452357 clinical trial testing PLDR safety and TME normalization potential in pancreatic cancer patients. The HOST-Factor will be used in samples collected from this trial to validate its potential as a key tool for personalized medicine in this aggressive disease.

Testosterone modulates vasodilation in mesenteric arteries of hypertensive rats.

AIMS: To evaluate the effects of testosterone on endothelium-dependent vasodilation and oxidative stress in mesenteric resistance arteries. MAIN METHODS: Spontaneously hypertensive rats (SHR), aged 8 to 10 weeks, were divided into four groups: intact (SHAM), intact treated with testosterone (TTO; 3 mg/kg/day) via subcutaneous route (s.c.), intact treated with testosterone and anastrozole [aromatase enzyme inhibitor (TTO + ANA; 0.1 mg/kg/day, s.c.)] and intact treated with testosterone and finasteride [5 α-reductase enzyme inhibitor (TTO + FIN; 5 mg/kg/day, s.c.)] for four weeks. Concentration-response curves to acetylcholine (ACh, 0.1 nmol/L - 10 µmol/L) were obtained in mesenteric resistance arteries previously contracted with phenylephrine (PE, 3 µmol/L), before and after the use of selective inhibitors. Reactive oxygen species (ROS) levels were assessed in the vessels and the endothelium analyzed by scanning electron microscopy. KEY FINDINGS: TTO group showed a lower participation of nitric oxide (NO), increased oxidative stress, and participation of prostanoids and endothelium-dependent hyperpolarization (EDH), possibly to maintain the vasodilator response. Lower participation of NO and prostanoids, combined to an increased participation of EDH, were observed in the TTO + ANA group, in addition to higher levels of ROS and altered endothelial morphology. The vasodilation to ACh was impaired in TTO + FIN, along increased participation of NO, reduction of prostanoids, and greater EDH-dependent vasodilation. SIGNIFICANCE: Testosterone contributes to endothelial vasodilation by enhancing EDH through an increased participation of epoxyeicosatrienoic acids. While the decrease in NO appears to involve the participation of dihydrotestosterone, 17 ß-estradiol seems to stimulate the action of the NO pathway and prostanoids.

Coping strategies for chronically ill children and adolescents facing the COVID-19 pandemic.

OBJECTIVE: to understand the experiences and coping strategies of children and adolescents with chronic illnesses during the COVID-19 pandemic. METHODS: a descriptive study, with a qualitative approach, carried out with six children and adolescents at the reception of an outpatient clinic of a pediatric hospital in the state of Ceará. Data collection took place from April to September 2021, using story-drawing, analyzed in light of Coutinho's criteria. RESULTS: two thematic categories emerged: Situations experienced by children and adolescents in times of COVID-19; Coping strategies for children and adolescents in their chronic illness process during the COVID-19 pandemic. FINAL CONSIDERATIONS: understanding the experiences and coping strategies of children and adolescents with chronic illness demonstrated the expression of creative imagination, incorporated by subjective components, which brings to light an approximation with the reality perceived and interpreted in a context of the COVID-19 pandemic.

Uma Escola em Movimento: a experiência da Escola Nacional Paulo Freire / A School on the Move: the experience of the Paulo Freire National School / Una Escuela en Movimiento: la experiencia de la Escuela Nacional Paulo Freire

A finalidade deste artigo é apresentar o trabalho da Escola Nacional Paulo Freire, a partir dos seus antecedentes históricos, dos movimentos que a constroem e objetivos e desafios atuais. O texto também retoma o sentido da homenagem a Paulo Freire e as principais influências do educador no processo político-pedagógico da escola. (AU)

The objective of this work is to present the work of the Escola Nacional Paulo Freire, from its historical antecedents, the movements that build it and current objectives and challenges. The text also takes up the meaning of the homage to Paulo Freire and the main influences of the educator in our political-pedagogical process.(AU)

El objetivo de este trabajo es presentar el trabajo de la Escola Nacional Paulo Freire, desde sus antecedentes históricos, los movimientos que la construyen y los objetivos y desafíos actuales. El texto también retoma el sentido del homenaje a Paulo Freire y las principales influencias del educador en nuestro proceso político-pedagógico. (AU)

Netrin-1 feedforward mechanism promotes pancreatic cancer liver metastasis via hepatic stellate cell activation, retinoid, and ELF3 signaling.

The biology of metastatic pancreatic ductal adenocarcinoma (PDAC) is distinct from that of the primary tumor due to changes in cell plasticity governed by a distinct transcriptome. Therapeutic strategies that target this distinct biology are needed. We detect an upregulation of the neuronal axon guidance molecule Netrin-1 in PDAC liver metastases that signals through its dependence receptor (DR), uncoordinated-5b (Unc5b), to facilitate metastasis in vitro and in vivo. The mechanism of Netrin-1 induction involves a feedforward loop whereby Netrin-1 on the surface of PDAC-secreted extracellular vesicles prepares the metastatic niche by inducing hepatic stellate cell activation and retinoic acid secretion that in turn upregulates Netrin-1 in disseminated tumor cells via RAR/RXR and Elf3 signaling. While this mechanism promotes PDAC liver metastasis, it also identifies a therapeutic vulnerability, as it can be targeted using anti-Netrin-1 therapy to inhibit metastasis using the Unc5b DR cell death mechanism.

Utilización de imágenes de pacientes para marketing médico

El uso de estrategias de imagen en las redes sociales médicas está cada vez más extendido, cumpliendo el límite ético establecido por el CEM. Sabiendo esto, el presente estudio buscó comprender el problema de la exposición de los pacientes en las redes sociales médicas. Para ello, se realizó una revisión bibliográfica a partir de las bases Scientific Electronic Library Online (Scielo), PubMED, UpToDate, LILACS, incluyendo artículos en inglés, español y portugués publicados a partir de 2018. Así, se percibió en algunas ciudades la tendencia a crear leyes para regular esta exposición, dado que el uso de imágenes se ha vuelto rutinario en la publicidad médica, como una forma de demostrar resultados. Sin embargo, esta práctica está muy acompañada de faltas éticas como recomienda el CFM.

The use of imagem strategies in medical socieal networks is increasingly widespread, meeting the ethical limit established by the CEM. Knowing this, the present study sought to understand the problem of patient exposure in medical social networks. For this, a literature review was carried out from the Scientific Electronic Library Online (Scielo), Pubmed, UpToDate, LILACS databases, articles in English, Spanish and Portuguese published from 2018 onwards were included. Thus, a tendency was noticed in some cities to create laws to regulate this exposure, given that the use of images has become routine in medical advertising, as a way to demonstrate results. However, this practice is greatly accompanied by ethical failures as recommended by the CFM.

A utilização das estratégias de imagem nas redes sociais médicas está cada vez mais disseminada, encontrando-se no limite ético estabelecido pelo CEM. Sabendo disso, o presente estudo buscou entender a problemática da exposição do paciente nas redes sociais médicas. Para isso, foi feita uma revisão da literatura a partir das bases Scientific Eletronic Library Online (Scielo), PubMED, UpToDate, LILACS, foram incluídos artigos em inglês, espanhol e português publicados a partir de 2018. Assim, percebeu-se em algumas cidades a tendência de criar leis para regular essa exposição, haja vista que a utilização de imagens tornou-se rotineira na propaganda médica, como forma demonstrar resultados. Todavia, tal prática vem acompanhada grandemente de falhas éticas segundo o preconizado pelo CFM.

Trogocytosis of cancer-associated fibroblasts promotes pancreatic cancer growth and immune suppression via phospholipid scramblase anoctamin 6 (ANO6).

In pancreatic ductal adenocarcinoma (PDAC), the fibroblastic stroma constitutes most of the tumor mass and is remarkably devoid of functional blood vessels. This raises an unresolved question of how PDAC cells obtain essential metabolites and water-insoluble lipids. We have found a critical role for cancer-associated fibroblasts (CAFs) in obtaining and transferring lipids from blood-borne particles to PDAC cells via trogocytosis of CAF plasma membranes. We have also determined that CAF-expressed phospholipid scramblase anoctamin 6 (ANO6) is an essential CAF trogocytosis regulator required to promote PDAC cell survival. During trogocytosis, cancer cells and CAFs form synapse-like plasma membranes contacts that induce cytosolic calcium influx in CAFs via Orai channels. This influx activates ANO6 and results in phosphatidylserine exposure on CAF plasma membrane initiating trogocytosis and transfer of membrane lipids, including cholesterol, to PDAC cells. Importantly, ANO6-dependent trogocytosis also supports the immunosuppressive function of pancreatic CAFs towards cytotoxic T cells by promoting transfer of excessive amounts of cholesterol. Further, blockade of ANO6 antagonizes tumor growth via disruption of delivery of exogenous cholesterol to cancer cells and reverses immune suppression suggesting a potential new strategy for PDAC therapy.

Infecção do sítio cirúrgico em pacientes submetidos a cirurgias neurológicas e ortopédicas / Infección del sitio quirúrgico en pacientes sometidos a cirugía neurológica y ortopédica / Surgical site infection in patients submitted to neurological and orthopedic surgeries abstract

RESUMO Objetivo: analisar a incidência das infecções de sítio cirúrgico (ISC) em pacientes submetidos a cirurgias neurológicas e ortopédicas e seus determinantes em um hospital público. Método: estudo de coorte retrospectivo, conduzido entre pacientes submetidos a cirurgias neurológicas e ortopédicas, de janeiro de 2015 a dezembro de 2020. Resultados: dos 3.029 procedimentos cirúrgicos realizados, 1.327 (43,8%) foram neurocirúrgicos; e 1.702 (56,2%), ortopédicos. A incidência da ISC foi 6,7% (89) em neurocirurgias e 3,3% (56) em ortopedias. A taxa global e de óbitos foi 4,8% e 12,4%, respectivamente. Na análise univariada, os fatores de risco associados às ISC em neurocirurgiasenvolveram tempo cirúrgico (>231 minutos), pontuação da American Society of Anesthesiologistsmaior que doise cirurgias emergenciais; para os procedimentos ortopédicos: cirurgias emergenciais, tempo de internação pré-operatório (>quatro dias) e cirúrgico (>149 minutos). Na análise multivariada, permaneceram cirurgias emergenciais e maior tempo cirúrgico como fatores de risco de ISC para ambas as especialidades;e, para as cirurgias ortopédicas e neurológicas, tempo de internação pré-operatório e classificação ASA, respectivamente. Conclusão: a taxa de incidência das ISC e de mortalidade bem como os fatores de risco identificados neste estudo devem ser considerados para elaborar estratégias destinadas a prevenir e controlar essas infecções.

RESUMEN Objetivo: analizar la incidencia de las infecciones de sitio quirúrgico (ISC) en pacientes sometidos a cirugías neurológicas y ortopédicas y sus determinantes en un hospital público. Método: estudio de cohorte retrospectivo, realizado entre pacientes sometidos a cirugías neurológicas y ortopédicas, de enero de 2015 a diciembre de 2020. Resultados: de los 3.029 procedimientos quirúrgicos realizados, 1.327 (43,8%) fueron neuroquirúrgicos; y 1.702 (56,2%), ortopédicos. La incidencia de la ISC fue 6,7% (89) en neurocirugía y 3,3% (56) en ortopedias. La tasa global y de muertes fue 4,8% y 12,4%, respectivamente. En el análisis univariado, los factores de riesgo asociados a las ISC en neurocirugía involucraron tiempo quirúrgico (>231 minutos), puntuación de la American Society of Anesthesiologists (ASA) mayor que dos y cirugías de emergencia; para los procedimientos ortopédicos: cirugías de emergencia, tiempo de internación preoperatorio (> cuatro días) y quirúrgico (>149 minutos). En el análisis multivariado, permanecieron cirugías de emergencia y mayor tiempo quirúrgico como factores de riesgo de ISC para ambas especialidades; y, para las cirugías ortopédicas y neurológicas, tiempo de internación preoperatorio y clasificación ASA, respectivamente. Conclusión: la tasa de incidencia de las ISC y de mortalidad, así como los factores de riesgo identificados en este estudio, debenser consideradosa la hora de elaborar estrategias para prevenir y controlar estas infecciones.

ABSTRACT Objective: to analyze the incidence of surgical site infections (SSI) in patients submitted to neurological and orthopedic surgeries and their determinants in a public hospital. Method: retrospective cohort study, conducted between patients submitted to neurological and orthopedic surgeries, from January 2015 to December 2020. Results: of the 3,029 surgical procedures performed, 1,327 (43.8%) were neurosurgical; and 1,702 (56.2%) were orthopedic. The incidence of SSI was 6.7% (89) in neurosurgeries and 3.3% (56) in orthopedic surgery. The overall rate and death rates were 4.8% and 12.4%, respectively. In the univariate analysis, the risk factors associated with SSI in neurosurgeries involved surgical time (>231 minutes), an American Society of Anesthesiologists score greater than two and emergency surgeries; the risk factors for orthopedic procedures were emergency surgeries, preoperative hospitalization time (> four days), and surgical procedures (>149 minutes). In the multivariate analysis, emergency surgeries and longer surgical time remained as risk factors for SSI for both specialties; the SSI risk factors for orthopedic and neurological surgeries were preoperative hospitalization time and ASA classification, respectively. Conclusion: the incidence rate of SSI and mortality, as well as the risk factors identified in this study, should be considered in order to develop strategies aimed at preventing and controlling these infections.

Os sentidos do aposentar-se na visão de sujeitos aposentados / The senses of retirement in the perspective of retired subjects

O artigo tem o objetivo de investigar como se dá o processo de interrupção do trabalhar no momento da aposentadoria e como os sujeitos passam por essa experiência em um cenário em que o trabalho é considerado fundamental na vida das pessoas. Foi utilizada metodologia qualitativa, composta por análise de narrativa de entrevistas realizadas com 20 sujeitos aposentados. Os resultados da pesquisa evidenciam que o fator financeiro é bastante relevante, no entanto existem aspectos subjetivos que não são ponderados no momento de parar de trabalhar. De maneira complementar, percebeu-se que ficar sem trabalho em uma sociedade produtivista faz com que os sujeitos se sintam desconfortáveis, mesmo tendo o direito legitimado para o descanso. Eles dizem se sentir julgados como inúteis e improdutivos pela sociedade, o que torna o ócio penoso em muitos momentos. Por fim, as narrativas demonstraram que se aposentar é percebido como ficar velho e sem perspectiva de futuro

The article aims to investigate how retirement occurs and is perceived by subjects in a society in which work is seen as fundamental in people's lives. A qualitative approach was used and data were collected and analysed through interviews with 20 subjects and narrative analysis. Results show that finances is quite a relevant factor when choosing to retire, while subjective aspects to this process are disregarded. Complementarily, not working in a productivity-bound society makes subjects uncomfortable, despite their legitimized right to rest. The participants reported feeling judged as useless and unproductive by society, which makes idleness painful in many moments. Finally, the narrative analysis showed that retiring is perceived as getting old and having no perspective for the future

NetrinG1+ cancer-associated fibroblasts generate unique extracellular vesicles that support the survival of pancreatic cancer cells under nutritional stress.

It is projected that in 5 years, pancreatic cancer will become the second deadliest cancer in the United States. A unique aspect of pancreatic ductal adenocarcinoma (PDAC) is its stroma; rich in cancer-associated fibroblasts (CAFs) and a dense CAF-generated extracellular matrix (ECM). These pathogenic stroma CAF/ECM units cause the collapse of local blood vessels rendering the tumor microenvironment nutrient-poor. PDAC cells are able to survive this state of nutrient stress via support from CAF-secreted material, which includes small extracellular vesicles (sEVs). The tumor-supportive CAFs possess a distinct phenotypic profile, compared to normal-like fibroblasts, expressing NetrinG1 (NetG1) at the plasma membrane, and active Integrin α5ß1 localized to the multivesicular bodies; traits indicative of poor patient survival. We herein report that NetG1+ CAFs secrete sEVs that stimulate Akt-mediated survival in nutrient-deprived PDAC cells, protecting them from undergoing apoptosis. Further, we show that NetG1 expression in CAFs is required for the pro-survival properties of sEVs. Additionally, we report that the above-mentioned CAF markers are secreted in distinct subpopulations of EVs; with NetG1 being enriched in exomeres, and Integrin α5ß1 being enriched in exosomes. Finally, we found that NetG1 and Integrin α5ß1 were detected in sEVs collected from plasma of PDAC patients, while their levels were significantly lower in plasma-derived sEVs of sex/age-matched healthy donors. The discovery of these tumor-supporting CAF-EVs elucidates novel avenues in tumor-stroma interactions and pathogenic stroma detection.

In Vitro Models to Study Angiogenesis and Vasculature.

The development of vasculature in vivo is an extremely complex process that requires temporal and spatial coordination between multiple cell types to produce an effective vessel. The formation of vasculature from preexisting blood vessels, known as angiogenesis, plays important roles in several physiological and pathological processes, including wound healing, organ development and growth, ischemia, inflammatory disorders, fibrosis, and cancer. Means to deconstruct these complicated biological systems are necessary to gain mechanistic insight into their development, function, and modulation that can be tested in in vivo models and ultimately the clinic. In this chapter, we will first review the classical in vitro techniques to study angiogenesis. Next, we will explore the exciting recent advances that rely on 3D multicellular systems to more accurately mimic vasculature development in vitro. Finally, we will discuss the applications of in vitro angiogenic methods to study related vasculature phenomena, such as vasculogenic mimicry.

In Vitro Tube Formation Assays in Matrigel.

Vasculature development is a combination of complex processes that require precise coordination of multiple cell types, through time and space, to generate functional blood-carrying vessels. Moreover, vasculature development can be altered when normal physiological conditions are disrupted, such as in cancer, and means to study blood vessels are of great importance. While the gold standard to explore these processes is the use of in vivo animal models, they are costly and time-consuming, and it is often difficult to dissect the molecular mechanisms involved. Thus, there are several ways to deconstruct vasculature development in vitro, in order to produce tunable systems that lead to a better understanding of cellular and molecular communication between different cell types involved, such as endothelial cells and supporting mesenchymal cells. In this method chapter, we will go into detail for one of the most popular ways of studying vasculature development in the context of cancer, which is the application of Matrigel to study tube formation of various cell types involved with vasculature development. We will provide step-by-step instructions to perform mono- and co-cultures of the major cells involved with the production of vasculature, how the results of these assays can be interpreted, and some advice to avoid common mistakes associated with Matrigel tube formation assays.

Antiproliferative Activity of Two Unusual Dimeric Flavonoids, Brachydin E and Brachydin F, Isolated from Fridericia platyphylla (Cham.) L.G.Lohmann: In Vitro and Molecular Docking Evaluation.

Despite the breakthrough in the development of anticancer therapies, plant-derived chemotherapeutics continue to be the basis of treatment for most types of cancers. Fridericia platyphylla is a shrub found in Brazilian cerrado biome which has cytotoxic, anti-inflammatory, and analgesic properties. The aim of this study was to investigate the antiproliferative potential of the crude hydroethanolic extract, subfraction (containing 59.3% of unusual dimeric flavonoids Brachydin E and 40.7% Brachydin F), as well as Brachydin E and Brachydin F isolated from F. platyphylla roots. The cytotoxic activity was evaluated in glioblastoma, lung, prostate, and colorectal human tumor cell lines. The crude hydroethanolic extract did not present cytotoxic activity, but its subfraction presented lower IC50 values for glioblastoma (U-251) and prostate adenocarcinoma (PC-3) cell lines. Brachydins E and F significantly reduced cell viability, proliferation, and clonogenic potential of PC-3, inducing them to the process of regulated cell death. In silico studies have indicated nuclear receptors as targets for Brachydins E and F, and molecular docking has pointed out their binding into glucocorticoid receptor (GR) ligand pocket. Targeting GR pathway has been described as a therapeutic strategy, especially for prostate cancer. These results suggest that Brachydin E and Brachydin F are promising compounds to be further explored for their antitumor effects.

Synthesis and Biological Evaluation of Cyclic Analogues from Nitrone LQB-278: A New Potential Antileukemia Compound.

BACKGROUND/AIM: A new set of LQB-nitrones and analogues was synthesized to evaluate anticancer activity based on the substitution of the terpenyl moiety of the antileukemic compound LQB-278 by the conformationally restricted cinnamyl ether. MATERIALS AND METHODS: A structure-activity relationship study was performed in vitro on Jurkat cells to screen the antileukemic activity of LQB-nitrones and analogues and elucidate the mechanisms of action of the most active derivatives. RESULTS: The cynamyl ramification and its ortho position aldehyde substitution improved the antileukemic activity. Three compounds showed an in vitro antiproliferative action, but only 5b induced apoptosis. Analysis of the molecular mechanisms showed increased expression of the cell cycle inhibitor p21CIP1/WAF1/Sdi1, caspase 3, Fas receptor, and Bax/Bcl-2 ratio. CONCLUSION: The cinnamyl derivative 5b (LQB-461) presented higher antileukemic effects than the prototype terpenyl nitrone, inducing Jurkat cell death by activating both extrinsic and intrinsic pathways of apoptosis. Therefore, this compound is a new promising candidate drug against leukemia.

Monocyclic Nitro-heteroaryl Nitrones with Dual Mechanism of Activation: Synthesis and Antileishmanial Activity.

5-Nitro-furan nitrones (1) and 5-nitro-thiophene nitrones (2) were synthesized in one step. Compounds 1a-c had the most potent leishmanicidal activity against intracellular amastigote forms of Leishmania amazonensis and L. infantum (from 0.019 to 2.76 µM), with excellent selectivity (from 39 to 5673). The comparison of the leishmanicidal activity in promastigotes of wild type L. donovani with those overexpressing nitroreductases NRT1 or NRT2 shows that 1a,b are activated by both, which could slow the development of resistance. Their redox potential (E redox) obtained by cyclic voltammetry (-0.67 and -0.62 V) shows that the reduction of the nitro group is modulated by the nitrone group. Oral administration of 1b to mice infected by L. infantum reduced the parasite load on the spleen by 76.6 and 95.0% with doses of 50 and 100 mg/kg, respectively, administered twice a day, for 5 days. In the liver, the parasite load suppression was above 75% with either treatment.

VITAMIN B12 AND HOMOCYSTEINE LEVELS IN PATIENTS WITH NAFLD: A SYSTEMATIC REVIEW AND METANALYSIS.

BACKGROUND: The vitamin B12 absorption can be affected in patients with nonalcoholic fatty liver disease (NAFLD), and low serum vitamin B12 levels has been related to the high homocysteine (HCY) levels and to the degree of NAFLD. OBJECTIVE: To carry out a systematic review and metanalysis of serum vitamin B12 and HCY levels in patients with NAFLD. METHODS: Original studies including serum vitamin B12 and HCY levels in humans with NAFLD were included. The searches were performed in four databases. RESULTS: 159 studies were identified, and after excluding the duplicates and non-eligible titles, eight original articles were included. Six out of eight showed higher B12 levels in NAFLD patients (404.9±136.2 pg/mL in relation to controls 353.91±117.3 pg/mL). Seven of the eight studies also showed higher HCY levels in NAFLD patients (14.2±3.44 umol/L in relation to controls 11.05±3.6 umol/L). The results for serum vitamin B12 and HCY levels were submitted to metanalysis, showing no difference in the vitamin B12 levels between patients with NAFLD and controls. However, the levels of Hcy were higher in NAFLD patients than in controls. CONCLUSION: There was no relashionship between the vitamin B12 levels and NAFLD. The levels of HCY were significantly higher in patients with NAFLD, suggesting this could be a potential marker for liver damage.

Intermittent Hypobaric Hypoxic Preconditioning Provides Neuroprotection by Increasing Antioxidant Activity, Erythropoietin Expression and Preventing Apoptosis and Astrogliosis in the Brain of Adult Rats Exposed to Acute Severe Hypoxia.

BACKGROUND: Exposure to intermittent hypoxia has been demonstrated to be an efficient tool for hypoxic preconditioning, preventing damage to cells and demonstrating therapeutic benefits. We aimed to evaluate the effects of respiratory intermittent hypobaric hypoxia (IHH) to avoid brain injury caused by exposure to acute severe hypoxia (ASH). METHODS: biomarkers of oxidative damage, mitochondrial apoptosis, and transcriptional factors in response to hypoxia were assessed by Western blot and immunohistochemistry in brain tissue. Four groups of rats were used: (1) normoxic (NOR), (2) exposed to ASH (FiO2 7% for 6 h), (3) exposed to IHH for 3 h per day over 8 days at 460 mmHg, and (4) ASH preconditioned after IHH. RESULTS: ASH animals underwent increased oxidative-stress-related parameters, an upregulation in apoptotic proteins and had astrocytes with phenotype forms compatible with severe diffuse reactive astrogliosis. These effects were attenuated and even prevented when the animals were preconditioned with IHH. These changes paralleled the inhibition of NF-κB expression and the increase of erythropoietin (EPO) levels in the brain. CONCLUSIONS: IHH exerted neuroprotection against ASH-induced oxidative injury by preventing oxidative stress and inhibiting the apoptotic cascade, which was associated with NF-κB downregulation and EPO upregulation.