Lack of effective treatments for aggressive breast cancer is still a major global health problem. We have previously reported that photodynamic therapy using methylene blue as photosensitizer ...(MB-PDT) massively kills metastatic human breast cancer, marginally affecting healthy cells. In this study, we aimed to unveil the molecular mechanisms behind MB-PDT effectiveness and specificity towards tumor cells. Through lipidomics and biochemical approaches, we demonstrated that MB-PDT efficiency and specificity rely on polyunsaturated fatty acid-enriched membranes and on the better capacity to deal with photo-oxidative damage displayed by non-tumorigenic cells. We found out that, in tumorigenic cells, lysosome membrane permeabilization is accompanied by ferroptosis and/or necroptosis. Our results also pointed at a cross-talk between lysosome-dependent cell death (LDCD) and necroptosis induction after photo-oxidation, and contributed to broaden the understanding of MB-PDT-induced mechanisms and specificity in breast cancer cells. Therefore, we demonstrated that efficient approaches could be designed on the basis of lipid composition and metabolic features for hard-to-treat cancers. The results further reinforce MB-PDT as a therapeutic strategy for highly aggressive human breast cancer cells.
Purpose This study aimed to assess the exercise capacity and muscle strength in elderly people using drugs for angiotensin-II blockage. Subjects and Methods Four hundred and seven older adults were ...recruited for this study. Data about comorbidities and medication use were recorded and the individuals were divided into three groups: control group- elderly people with normal exercise capacity (n=235); angiotensin-converting enzyme inhibitor group − individuals using angiotensin-converting enzyme inhibitors (n=140); and angiotensin-II receptor blocker group- patients using angiotensin-II receptor blockers (n= 32). Exercise capacity was evaluated by a 6-minute walking test and muscle strength was measured using a handgrip dynamometer. Results Patients from the angiotensin-converting enzyme inhibitor group (mean: 99 ± 12%) and the angiotensin-II receptor blocker group (mean: 101 ± 14%) showed higher predicted values in the 6-minute walking test than the control group patients (mean: 96 ± 10%). Patients from the angiotensin-converting enzyme inhibitor group (mean: 105 ± 19%) and the angiotensin-II receptor blocker group (mean: 105.1 ± 18.73%) showed higher predicted values of muscle strength than control group patients (mean: 98.15 ± 18.77%). Conclusion Older adults using angiotensin-converting enzyme inhibitors or angiotensin-II receptor blockers have better functional exercise capacity and muscle strength.
Recently, castellated columns have been increasingly used in buildings because of their flexibility, easy compatibility and potential savings due to less steel consumption. However, there is a lack ...of research related to the subject. In view of that, this work evaluates the influence of the opening type and size on the resistant capacity of the column, considering a nonlinear plastic analysis by the finite element method (792 simulations). For this, columns without openings were modeled to validate the methodology proposed. After validation, a nonlinear buckling analysis of castellated columns was performed. In this study, different cut patterns of the beam web are evaluated, as well as residual stresses, material and geometric imperfections, based on a statistical design. The loads obtained by castellated columns and columns without web are compared. Also, the resistance reduction factors associated with global buckling (χ) for castellated profiles are compared to the values proposed by ABNR NBR 8800 (2008). Furthermore, statistically, there are no differences between the opening types evaluated. Finally, in order to contribute to the design of castellated columns, equations based on regression models were found to predict the load capacity of these elements.
We report a series of 1,3-diphenylureido hydroxamate HDAC inhibitors evaluated against sensitive and drug-resistant P. falciparum strains. Compounds 8a-d show potent antiplasmodial activity, ...indicating that a phenyl spacer allows improved potency relative to cinnamyl and di-hydrocinnamyl linkers. In vitro, mechanistic studies demonstrated target activity for PfHDAC1 on a recombinant level, which agreed with cell quantification of the acetylated histone levels. Compounds 6c, 7c, and 8c, identified as the most active in phenotypic assays and PfHDAC1 enzymatic inhibition. Compound 8c stands out as a remarkable inhibitor, displaying an impressive 85% inhibition of PfHDAC1, with an IC
value of 0.74 µM in the phenotypic screening on Pf3D7 and 0.8 µM against multidrug-resistant PfDd2 parasites. Despite its potent inhibition of PfHDAC1, 8c remains the least active on human HDAC1, displaying remarkable selectivity. In silico studies suggest that the phenyl linker has an ideal length in the series for permitting effective interactions of the hydroxamate with PfHDAC1 and that this compound series could bind as well as in HsHDAC1. Taken together, these results highlight the potential of diphenylurea hydroxamates as a privileged scaffold for the generation of potent antimalarial HDAC inhibitors with improved selectivity over human HDACs.
The success of islet transplantation has improved lately. Unfortunately, it is still compromised by cell loss. We have shown that prolactin (PRL) inhibits beta-cell apoptosis and up-regulates the ...antiapoptotic Heat Shock Protein B1 (HSPB1) in human islets. Since its function in pancreatic islets has not been studied, we explored the role of HSPB1 in PRL-induced beta-cell survival. The significant PRL-induced cytoprotection in control cells was abrogated in HSPB1 silenced cells, overexpression of HSPB1 recovered survival. PRL-mediated inhibition of cytokine-induced caspase activities and cytokine-induced decrease of BCL-2/BAX ratio was significantly reverted in knocked-down cells. Kinetics of HSPB1 and HSF1 expression were studied in primary cultures of murine and human pancreatic islets. These findings are highly relevant for the improvement of clinical islet transplantation success rate since our results demonstrated a key role for HSPB1 pointing it as a promising target for beta-cell cytoprotection through the up-regulation of an endogenous protective pathway.
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•HSPB1 displays a key role in PRL-induced cytoprotection on mouse beta-cells.•HPSB1 induction inhibits caspase activation and thus promotes beta-cell survival.•PRL promotes an up-regulation of HSF1 and HSPB1 in pancreatic islet cells.•Increasing HSPB1 levels promotes the same beneficial effects as PRL exposure.
During type 1 diabetes mellitus (T1DM) development, beta-cells undergo intense endoplasmic reticulum (ER) stress that could result in apoptosis through the failure of adaptation to the unfolded ...protein response (UPR). Islet transplantation is considered an attractive alternative among beta-cell replacement therapies for T1DM. To avoid the loss of beta-cells that will jeopardize the transplant’s outcome, several strategies are being studied. We have previously shown that prolactin induces protection against proinflammatory cytokines and redox imbalance-induced beta-cell death by increasing heat-shock protein B1 (HSPB1) levels. Since the role of HSPB1 in beta cells has not been deeply studied, we investigated the mechanisms involved in unbalanced protein homeostasis caused by intense ER stress and overload of the proteasomal protein degradation pathway. We tested whether HSPB1-mediated cytoprotective effects involved UPR modulation and improvement of protein degradation via the ubiquitin-proteasome system. We demonstrated that increased levels of HSPB1 attenuated levels of pro-apoptotic proteins such as CHOP and BIM, as well as increased protein ubiquitination and the speed of proteasomal protein degradation. Our data showed that HSPB1 induced resistance to proteotoxic stress and, thus, enhanced cell survival via an increase in beta-cell proteolytic capacity. These results could contribute to generate strategies aimed at the optimization of beta-cell replacement therapies.
Photodynamic therapy (PDT) appears as a promising alternative in the treatment of breast cancer since it can be highly effective in curing cancer while preserving normal tissue. However, predicting ...outcomes in PDT still constitutes a great challenge. One of the parameters that are usually empirically determined is the rate of photon flux delivered to the tissue (light fluence rate). In the present study, we intended to understand why monolayers of human cells derived from mammary adenocarcinomas (MDA‐MB‐231 and MCF‐7) respond quite differently to fluence rates (cells were irradiated either for 6 or for 16 min) at a fixed light dose (4.5 J cm−2) delivered with an array of LEDs in a typical methylene blue PDT protocol. While death rates of MDA‐MB‐231 cells were insensitive to the fluence rate, MCF‐7 cells showed a quite impressive (three times) decrease in cell death levels in the shorter irradiation protocol. Independent on cell type cell death was invariably correlated with the depletion of reduced glutathione intracellular levels and consequently with widespread redox misbalance. Our data show the potential to optimize fluence rates to provide exhaustion of the cell antioxidant responses in order to circumvent therapy resistance of breast tumors.
When MB is activated using a low fluence rate, this results in GSH depletion and ROS accumulation, culminating in cell death for both cell types. However, the basal intracellular GSH content can determine the cell sensitivity in a high energy fluence rate MB‐PDT protocol. TNBC cells presents less GSH content and more susceptibility to respond to the high energy fluence rate. Unlike TNBC cells, luminal A cells display higher levels of GSH, and when submitted to MB‐PDT using high energy fluence rate, a less pro‐oxidative milieu is generated leading to lower levels of cell death.
Placental malaria (PM) is associated with severe inflammation leading to abortion, preterm delivery, and intrauterine growth restriction. Innate immunity responses play critical roles, but the ...mechanisms underlying placental immunopathology are still unclear. Here, we investigated the role of inflammasome activation in PM by scrutinizing human placenta samples from an endemic area and ablating inflammasome components in a PM mouse model. The reduction in birth weight in babies from infected mothers is paralleled by increased placental expression of AIM2 and NLRP3 inflammasomes. Using genetic dissection, we reveal that inflammasome activation pathways are involved in the production and detrimental action of interleukin-1β (IL-1β) in the infected placenta. The IL-1R pharmacological antagonist Anakinra improved pregnancy outcomes by restoring fetal growth and reducing resorption in an experimental model. These findings unveil that IL-1β-mediated signaling is a determinant of PM pathogenesis, suggesting that IL-1R antagonists can improve clinical outcomes of malaria infection in pregnancy.
Pancreatic ductal adenocarcinomas (PDAC) are the fourth leading cause of death due to neoplasms. In view of the urgent need of effective treatments for PDAC, photodynamic therapy (PDT) appears as a ...promising alternative. However, its efficacy against PDAC and the mechanisms involved in cell death induction remain unclear. In this study, we set out to evaluate PDT's cytotoxicity using methylene blue (MB) as a photosensitizer (PS) (MB-PDT) and to evaluate the contribution of necroptosis in its effect in human PDAC cells. Our results demonstrated that MB-PDT induced significant death of different human PDAC models presenting two different susceptibility profiles. This effect was independent of MB uptake or its subcellular localization. We found that the ability of triggering necroptosis was determinant to increase the treatment efficiency. Analysis of single cell RNA-seq data from normal and neoplastic human pancreatic tissues showed that specific necroptosis proteins RIPK1, RIPK3 and MLKL presented significant higher expression levels in cells displaying a transformed phenotype providing further support to the use of approaches that activate necroptosis, like MB-PDT, as useful adjunct to surgery of PDAC to tackle the problem of microscopic residual disease as well as to minimize the chance of local and metastatic recurrence.
•We describe the typification of polar compounds of twelve cuts obtained from a true boiling point system.•We examine changes in the cuts composition by ESI(−) FT-ICR MS analysis.•A correlation ...between the composition and TAN, total sulfur and the corrosion process was performed.•The structures of some naphthenic acids, phenols and pyridines were confirmed using ESI(±)-MS/MS.
In this work, electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI(±)-FT-ICR MS) was applied in the chemical characterization of polar compounds. These compounds were identified as the oxygen-containing compound classes (naphthenic acids, O2 class, and phenols, O1 class), the sulfur-containing compound classes (mainly sulfides, S1 class), and the basic and non-basic nitrogen-containing compound classes (carbazoles and pyridines, N class). For access the sulfur-containing compounds were employed the methylation reactions. As the increasing of distillation cut temperature, the amount of O2 compounds increased (from 9 for cut 2 to 66 for cut 12), and the average molecular weight distribution, Mw, shifted to higher m/z values (Mw=169→321Da). These results were consistent with the increase of TAN with the boiling point. Plots of the DBE versus the carbon number for the O2 class of heavy distillation cuts (cuts 4–12) suggested a maximum abundance of the carbon numbers located at C12–C18 with a constant DBE of 3. For the nitrogen-containing compounds, 100 compounds were detected with m/z ranging from 160 to 414. Similar to O2 class, the amount of nitrogen species increased, and the Mw shifted for high values in function of distillation cut temperature: 6 species and Mw=206Da for cut 3; and 64 species and Mw=340Da for cut 12. The structures and the connectivity of naphthenic acids, phenols and pyridines were confirmed using ESI(±)-MS/MS. The most abundant sulfur compounds in heavy distillation cuts presented a carbon number of C23 (for cut 11) and C25 (for cut 12) with constant DBE of 3. Results of ESI(±)-FT-ICR MS contributed to the understanding of the chemical composition of Brazilian crude oil and the establishment of a correlation with the corrosion process.
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