Effector CD4+ T cell subsets in Takayasu arteritis - Differences between the peripheral blood and the aorta.

Takayasu arteritis (TAK) is a granulomatous vasculitis that affects large arteries. T cells are important in TAK pathophysiology as these cells orchestrate granulomatous infiltration in arteries. This study aims to evaluate effector CD4+ T cells in the peripheral blood and the aortic wall of TAK patients and to analyze associations with disease activity and therapy. We performed a longitudinal study including 30 TAK patients and 30 controls. CD3+ T cells, CD3+CD4- T cells, CD4+ T cells, and Th1, Th2, and Th17 cells were evaluated in peripheral blood by flow cytometry, and the expression of CD4, CD8, Tbet, GATA-3, and RORγT was analyzed in the aorta of 6 patients by immunohistochemistry. TAK patients presented lower CD3+ T cells and CD4+ T cells (p=0.031 and p=0.039, respectively) than controls. Patients with active disease and those in remission had higher proportions of Th17 cells than controls (p=0.016 and p=0.004, respectively). Therapy for TAK did not result in significant differences concerning CD4+ effector T cell subpopulations. Disease duration correlated with the number and percentage of Th2 cells (rho=-0.610 and rho=-0.463, respectively) and with Th17 cells (rho=-0.365 and rho=-0.568). In the aorta, the expression of CD8 was higher than CD4, whereas GATA-3, Tbet and RORγT were expressed in this order of frequency. In conclusion, TAK patients present an increased Th17 response in the peripheral blood regardless of disease activity, whereas in the aortic tissue CD8 cells and the Th2 response were predominant.

Design and Synthesis of Novel 3-Nitro-1H-1,2,4-triazole-1,2,3-triazole-1,4-disubstituted Analogs as Promising Antitrypanosomatid Agents: Evaluation of In Vitro Activity against Chagas Disease and Leishmaniasis.

A series of 28 compounds, 3-nitro-1H-1,2,4-triazole, were synthesized by click-chemistry with diverse substitution patterns using medicinal chemistry approaches, such as bioisosterism, Craig-plot, and the Topliss set with excellent yields. Overall, the analogs demonstrated relevant in vitro antitrypanosomatid activity. Analog 15g (R1 = 4-OCF3-Ph, IC50 = 0.09 µM, SI = >555.5) exhibited an outstanding antichagasic activity (Trypanosoma cruzi, Tulahuen LacZ strain) 68-fold more active than benznidazole (BZN, IC50 = 6.15 µM, SI = >8.13) with relevant selectivity index, and suitable LipE = 5.31. 15g was considered an appropriate substrate for the type I nitro reductases (TcNTR I), contributing to a likely potential mechanism of action for antichagasic activity. Finally, 15g showed nonmutagenic potential against Salmonella typhimurium strains (TA98, TA100, and TA102). Therefore, 3-nitro-1H-1,2,4-triazole 15g is a promising antitrypanosomatid candidate for in vivo studies.

Recent Trends in Curcumin-Containing Inorganic-Based Nanoparticles Intended for In Vivo Cancer Therapy.

Curcumin is a natural compound that has been widely investigated thanks to its various biological properties, including antiproliferative. This molecule acts on different cancers such as lung, breast, pancreatic, colorectal, etc. However, the bioactive actions of curcumin have limitations when its physicochemical properties compromise its pharmacological potential. As a therapeutic strategy against cancer, curcumin has been associated with inorganic nanoparticles. These nanocarriers are capable of delivering curcumin and offering physicochemical properties that synergistically enhance anticancer properties. This review highlights the different types of curcumin-based inorganic nanoparticles and discusses their physicochemical properties and in vivo anticancer activity in different models of cancer.

Neuroprotective Profile of Triazole Grandisin Analogue against Amyloid-Beta Oligomer-Induced Cognitive Impairment.

Alzheimer's disease (AD) is a neurodegenerative disorder caused by accumulation of amyloid-ß oligomers (AßO) in the brain, neuroinflammation, oxidative stress, and cognitive decline. Grandisin, a tetrahydrofuran neolignan, exhibits relevant anti-inflammatory and antioxidant properties. Interestingly, grandisin-based compounds were shown to prevent AßO-induced neuronal death in vitro. However, no study has assessed the effect of these compounds on the AD animal model. This study focuses on a triazole grandisin analogue (TGA) synthesized using simplification and bioisosteric drug design, which resulted in improved potency and solubility compared with the parent compound. This study aimed to investigate the possible in vivo effects of TGA against AßO-induced AD. Male C57/Bl6 mice underwent stereotaxic intracerebroventricular AßO (90 µM) or vehicle injections. 24 h after surgery, animals received intraperitoneal treatment with TGA (1 mg/kg) or vehicle, administered on a 14 day schedule. One day after treatment completion, a novel object recognition task (NORT) was performed. Memantine (10 mg/kg) was administered as a positive control. NORT retention sessions were performed on days 8 and 16 after AßO injection. Immediately after retention sessions, animals were euthanized for cortex and hippocampus collection. Specimens were subjected to oxidative stress and cytokine analyses. TGA reduced the level of cortex/hippocampus lipoperoxidation and prevented cognitive impairment in AßO-injected mice. Additionally, TGA reduced tumor necrosis factor (TNF) and interferon-γ (IFN-γ) levels in the hippocampus. By contrast, memantine failed to prevent cortex/hippocampus lipid peroxidation, recognition memory decline, and AßO-induced increases in TNF and IFN-γ levels in the hippocampus. Thus, memantine was unable to avoid the AßO-induced persistent cognitive impairment. The results showed that TGA may prevent memory impairment by exerting antioxidant and anti-inflammatory effects in AßO-injected mice. Moreover, TGA exhibited a persistent neuroprotective effect compared to memantine, reflecting an innovative profile of this promising agent against neurodegenerative diseases, such as AD.

Biomarkers of oxidative stress and inflammation in subjects with COVID-19: Characterization and prognosis of the disease.

Coronavirus disease (COVID-19) is an acute respiratory disease caused by the new coronavirus (SARS-CoV-2) that has spread throughout the world causing millions of deaths. COVID-19 promotes excessive release of pro-inflammatory cytokines leading to acute lung injury and death. Reactive oxygen species (ROS) and oxidative stress (OS) may also play a role in the pathophysiology of COVID-19. The present study investigated levels of inflammatory cytokines (IL-1ß, IL-6, IL-8, IL-10, IL-12) and OS biomarkers (MPO, SOD, CAT, GST enzymes and contents of GSH, TBARS and PC) in patients with SARS-CoV-2 infection, which were correlated with disease severity. Patients with SARS significantly increased IL-1ß levels, while IL-6 levels were elevated in both groups of SARS-CoV-2 positive patients. The most severe patients showed increased levels of IL-8 and IL-10, while subjects without SARS showed lower values. MPO activity were higher in both groups of SARS-CoV-2 positive patients, while SOD and CAT activity were decreased in both groups. Compared to controls, GGT was elevated only in the SARS patient group, while GST values were increased in the group of positive patients in SARS-CoV-2 without SARS and were decreased in patients with SARS. GSH and UA contents decreased in SARS-CoV-2 positive subjects, whereas TBARS and PC contents increased in both groups of SARS-CoV-2 positive patients, particularly in the SARS patient group. In addition, several important correlations were found between cytokines and the different OS parameters suggesting some inter-relationship in the complex antioxidant system of the patients. In general, patients with SARS-CoV-2 infection showed higher levels of OS biomarkers, and also elevated contents of IL-6 and IL-10, probably worsening the damage caused by SARS-CoV-2 infection. This damage may contribute to the severity of the disease and its complications, as well as a prognosis for SARS-CoV-2 patients.

Protein restriction impairs the response activation/responsivity of MAPK signaling pathway of hematopoietic stem cells.

Protein restriction (PR) leads to bone marrow hypoplasia with changes in stromal cellularity components of the extracellular matrix in hematopoietic stem cells (HSCs). However, the underlying signaling mechanisms are poorly understood. We hypothesize that PR impairs the HSC mitogen-activated protein kinase (MAPK) signaling pathway response activation. Our aim is to evaluate the activation of MAPK and interleukin-3 (IL-3) proteins in HSC to explain PR-induced bone marrow hypoplasia, which causes altered proliferation and differentiation. C57BL/6 male mice were subjected to a low-protein diet (2% protein) or normoproteic (12% protein). PKC, PLCγ2, CaMKII, AKT, STAT3/5, ERK1/2, JNK, and p38d phosphorylation were evaluated by flow cytometry, and GATA1/2, PU.1, C/EBPα, NF-E2, and Ikz-3 genes (mRNAs) assessed by quantitative real-time-polymerase chain reaction. Pathway proteins, such as PLCγ2, JAK2, STAT3/5, PKC, and RAS do not respond to the IL-3 stimulus in PR, leading to lower activation of ERK1/2 and Ca2+ signaling pathways, consequently lowering the production of hematopoietic transcription factors. Colony forming units granulocyte-macrophage and colony forming units macrophage formation are impaired in PR even after being stimulated with IL-3. Long-term hematopoietic stem cells, short-term hematopoietic stem cells, granulocyte myeloid progenitor, and megakaryocyte-erythroid progenitor cells were significantly reduced in PR animals. This study shows for the first time that activation of MAPK pathway key proteins in HSCs is impaired in cases of PR. Several pathway proteins, such as PLCγ2, JAK2, STAT3, PKC, and RAS do not respond to IL-3 stimulation, leading to lower activation of extracellular signal-regulated protein kinase 1/2 and consequently lower production of hematopoietic transcription factors GATA1/2, PU.1, C/EBPa, NF-E2, and Ikz3. These changes result in a reduction in colony-forming units, proliferation, and differentiation, leading to hypocellularity.

In Vivo Antileishmanial Effect of 3,5-Diaryl-isoxazole Analogues Based on Veraguensin, Grandisin, and Machilin G: A Glance at a Preclinical Study.

New treatment approaches targeting cutaneous leishmaniasis (CL) are required since conventional drugs exhibit limitations due to their several adverse effects and toxicity. In this study, we aimed to evaluate the in vivo intralesional treatment efficacy of five isoxazole derivatives previously synthesized and effective in vitro against intracellular amastigote forms of Leishmania (L.) amazonensis. Among the tested analogues, 7 exhibited relevant in vivo therapeutic effects. The in silico predictions provided interesting information about the toxicity, suggesting the safety of analogue 7. Experiments performed with Salmonella typhimurium strains (TA98, TA100, and TA102) showed a non-mutagenicity profile of 7. The treatment of Leishmania-infected BALB/c mice with isoxazole 7 showed remarkably smaller CL lesions and decreased the parasitism (by 98.4%) compared to the control group. Hence, analogue 7 is a promising drug candidate and alternative treatment for CL caused by L. amazonensis.

Monocyte subsets and monocyte-related chemokines in Takayasu arteritis.

The pathogenesis of Takayasu arteritis (TAK) is poorly understood and no previous studies have analyzed monocytes in TAK. This study evaluated monocyte subsets and monocyte-related chemokines in the peripheral blood of TAK patients and healthy controls (HC). Monocyte subsets were identified as classical (CD14+CD16-), intermediate (CD14+CD16dim), and non-classical (CD14dimCD16high) in the peripheral blood. The chemokines CCL (C-C chemokine ligand)2, CCL3, CCL4, CCL5, CCL7, CXCL (C-X-C motif ligand)10, and CX3CL (C-X3-C motif ligand)1 were measured in the sera. Thirty-two TAK patients and 30 HC were evaluated. Intermediate monocytes were higher in TAK than HC [25.0 cells ×106/L (16.7-52.0) vs. 17.2 cells ×106/L (9.2-25.3); p = 0.014]. Active disease was associated with monocytosis (p = 0.004), increased classical (p = 0.003), and intermediate (p < 0.001) subsets than HC. Prednisone reduced the percentage of non-classical monocytes (p = 0.011). TAK patients had lower CCL3 (p = 0.033) and CCL4 (p = 0.023) levels than HC, whereas CCL22 levels were higher in active TAK compared to the remission state (p = 0.008). Glucocorticoids were associated with lower CXCL10 levels (p = 0.012). In TAK, CCL4 correlated with total (Rho = 0.489; p = 0.005), classical and intermediate monocytes (Rho = 0.448; p = 0.010 and Rho = 0.412; p = 0.019). In conclusion, TAK is associated with altered counts of monocyte subsets in the peripheral blood compared to HC and CCL22 is the chemokine with the strongest association with active disease in TAK.

Selenylated Imidazo[1,2-a]pyridine Induces Cell Senescence and Oxidative Stress in Chronic Myeloid Leukemia Cells.

Imidazo[1,2-a]pyridines (IPs) have been studied regarding drug development. The objective of this work was to evaluate the antileukemic capacity of IP derivatives by screening their ability as a pro-oxidant. IP derivatives were synthesized and oral bioavailability and toxicity were analyzed in silico. Redox screening was performed on human Kasumi, KG-1, K562, and Jurkat leukemia cells. The IP derivative and the most responsive leukemic cell were selected for cytotoxicity, cell proliferation, cell senescence, and oxidative stress assays. The predictive toxicity analysis showed a possible effect on the reproductive system, but without mutagenic, carcinogenic, or irritability effects. MRK-107 against K562 cells was the compound that showed the best redox profile. MRK-107 did not induce cell death in K562 and monocyte cells. However, this compound was able to decrease cell proliferation and increase cell senescence after 48 and 72 h. Furthermore, MRK-107 induced oxidative stress in K562 cells after 72 h, increasing lipid peroxidation and decreasing reduced glutathione (GSH) contents. This study demonstrated that MRK-107-induced senescence with the involvement of oxidative stress is a possible mechanism of action, addressing this compound as a potential antitumor drug against chronic myeloid leukemia.

In Vitro Study of Cytotoxic Mechanisms of Alkylphospholipids and Alkyltriazoles in Acute Lymphoblastic Leukemia Models.

This study investigates the efficacy of miltefosine, alkylphospholipid, and alkyltriazolederivative compounds against leukemia lineages. The cytotoxic effects and cellular and molecular mechanisms of the compounds were investigated. The inhibitory potential and mechanism of inhibition of cathepsins B and L, molecular docking simulation, molecular dynamics and binding free energy evaluation were performed to determine the interaction of cathepsins and compounds. Among the 21 compounds tested, C9 and C21 mainly showed cytotoxic effects in Jurkat and CCRF-CEM cells, two human acute lymphoblastic leukemia (ALL) lineages. Activation of induced cell death by C9 and C21 with apoptotic and necrosis-like characteristics was observed, including an increase in annexin-V+propidium iodide-, annexin-V+propidium iodide+, cleaved caspase 3 and PARP, cytochrome c release, and nuclear alterations. Bax inhibitor, Z-VAD-FMK, pepstatin, and necrostatin partially reduced cell death, suggesting that involvement of the caspase-dependent and -independent mechanisms is related to cell type. Compounds C9 and C21 inhibited cathepsin L by a noncompetitive mechanism, and cathepsin B by a competitive and noncompetitive mechanism, respectively. Complexes cathepsin-C9 and cathepsin-C21 exhibited significant hydrophobic interactions, water bridges, and hydrogen bonds. In conclusion, alkyltriazoles present cytotoxic activity against acute lymphoblastic lineages and represent a promising scaffold for the development of molecules for this application.

First generation of multifunctional peptides derived from latarcin-3a from Lachesana tarabaevi spider toxin.

The need for discovering new compounds that can act selectively on pathogens is becoming increasingly evident, given the number of deaths worldwide due to bacterial infections or tumor cells. New multifunctional biotechnological tools are being sought, including compounds present in spider venoms, which have high biotechnological potential. The present work aims to perform the rational design and functional evaluation of synthetic peptides derived from Lachesana tarabaevi spider toxin, known as latarcin-3a. The antimicrobial activity was tested against Gram-positive and -negative bacteria, with minimum inhibitory concentrations (MIC) between 4 and 128 µg.ml-1. Anti-biofilm tests were then performed to obtain MICs, where the peptides demonstrated activity from 4 to 128 µg.ml-1. In vitro cell cytotoxicity assays were carried out from tumor cell lines, lineages C1498, Kasumi-1, K-562, Jurkat, MOLT4, and Raji. Erythrocyte integrity was evaluated in the presence of synthetic peptides analog, which did not promote hemolysis at 128 µg.ml-1. The peptide that showed the best antibacterial activity was Lt-MAP3 and the best antitumor was Lt-MAP2. In conclusion, rational design of multifunctional antimicrobial peptides may be promising alternative tools in the treatment of emerging diseases such as bacterial infections and tumor cells.

Effect of Ylang-Ylang (Cananga odorata Hook. F. & Thomson) Essential Oil on Acute Inflammatory Response In Vitro and In Vivo.

The aim of this study is to evaluate the phytochemical profile, oral acute toxicity, and the effect of ylang-ylang (Cananga odorata Hook. F. & Thomson) essential oil (YEO) on acute inflammation. YEO was analyzed by gas chromatography/mass spectrometry. For in vitro tests, YEO was assessed using cytotoxicity, neutrophil chemotaxis induced by N-formyl methionyl leucyl phenylalanine (fMLP), and phagocytic activity tests. YEO was orally administered in zymosan-induced peritonitis, carrageenan-induced leukocyte rolling, and adhesion events in the in situ microcirculation model and in carrageenan-induced paw edema models. YEO (2000 mg/kg) was also tested using an acute toxicity test in Swiss mice. YEO showed a predominance of benzyl acetate, linalool, benzyl benzoate, and methyl benzoate. YEO did not present in vitro cytotoxicity. YEO reduced the in vitro neutrophil chemotaxis induced by fMLP and reduced the phagocytic activity. The oral treatment with YEO reduced the leukocyte recruitment and nitric oxide production in the zymosan-induced peritonitis model, reduced rolling and adherent leukocyte number induced by carrageenan in the in situ microcirculation model, and reduced carrageenan-induced edema and mechanical hyperalgesia. YEO did not present signs of toxicity in the acute toxicity test. In conclusion, YEO affected the leukocyte activation, and presented antiedematogenic, anti-hyperalgesic, and anti-inflammatory properties.

Direct ionizing radiation and bystander effect in mouse mesenchymal stem cells.

Purpose: This study aimed to evaluate the radiation-induced direct and bystander (BYS) responses of mesenchymal stem cells (MSCs) and to characterize these cells radiobiologically.Methods and materials: MSCs were irradiated (IR) and parameters related to DNA damage and cellular signaling were verified in a dose range from 0.5 to 15 Gy; also a transwell insert co-culture system was used to study medium-mediated BYS effects.Results: The main effects on directly IR cells were seen at doses higher than 6 Gy: induction of cell death, cell cycle arrest, upregulation of p21, and alteration of redox status. Irrespective of a specific dose, induction of micronuclei formation, H2AX phosphorylation, and decreased Akt expression also occurred. Thus, mTOR expression, cell senescence, nitric oxide generation, and calcium levels, in general were not significantly modulated by radiation. Data from the linear-quadratic model showed a high alpha/beta ratio, which is consistent with a more exponential survival curve. BYS effects from the unirradiated MSCs placed into companion wells with the directly IR cells, were not observed.Conclusions: The results can be interpreted as a positive outcome, meaning that the radiation damage is restricted to the directed IR MSCs not leading to off-target cell responses.

A canthin-6-one derivative induces cell death by apoptosis/necroptosis-like with DNA damage in acute myeloid cells.

Natural products have long been considered a relevant source of new antitumor agents. Despite advances in the treatment of younger patients with acute myeloid leukemia (AML), the prognosis of elderly patients remains poor, with a high frequency of relapse. The cytotoxicity of canthin-6-one alkaloids has been extensively studied in different cell types, including leukemic strains. Among the canthin-6-one analogs tested, 10-methoxycanthin-6-one (Mtx-C) showed the highest cytotoxicity in the malignant AML cells Kasumi-1 and KG-1. Thus, we evaluated the cytotoxicity and cell death mechanisms related to Mtx-C using the EC50 (80 µM for Kasumi-1 and 36 µM for KG-1) treatment for 24 h. Our results identify reactive oxygen species production, mitochondrial depolarization, annexin V-FITC/7-AAD double staining, caspase cleave and upregulation of mitochondria-dependent apoptosis proteins (Bax, Bim, Bik, Puma and phosphorylation of p53) for both cell lineages. However, downregulation of Bcl-2 and the simultaneous execution of the apoptotic and necroptotic programs associated with the phosphorylation of the proteins receptor-interacting serine/threonine-protein kinase 3 and mixed lineage kinase domain-like pseudokinase occurred only in Kasumi-1 cells. About the lasted events, Kasumi-1 cell death was inhibited by pharmacological agents such as Zvad-FMK and necrostatin-1. The underlying molecular mechanisms of Mtx-C still include participation in the DNA damage and stress-signaling pathways involving p38 and c-Jun N-terminal mitogen-activated protein kinases and interaction with DNA. Thus, Mtx-C represents a promising tool for the development of new antileukemic molecules.

Chemodiversity and Anti-Leukemia Effect of Metabolites from Penicillium setosum CMLD 18.

Penicillium setosum represents a Penicillium species recently described, with little up-to-date information about its metabolic and biological potential. Due to this scenario, we performed chemical and biological studies of P. setosum CMLD18, a strain isolated from Swinglea glutinosa (Rutaceae). HRMS-MS guided dereplication strategies and anti-leukemia assays conducted the isolation and characterization of six compounds after several chromatographic procedures: 2-chloroemodic acid (2), 2-chloro-1,3,8-trihydroxy-6- (hydroxymethyl)-anthraquinone (7), 7-chloroemodin (8), bisdethiobis(methylthio)acetylaranotine (9), fellutanine C (10), and 4-methyl-5,6-diihydro-2H-pyran-2-one (15). From the assayed metabolites, (10) induced cellular death against Kasumi-1, a human leukemia cell line, as well as good selectivity for it, displaying promising cytotoxic activity. Here, the correct NMR signal assignments for (9) are also described. Therefore, this work highlights more detailed knowledge about the P. setosum chemical profile as well as its biological potential, offering prospects for obtaining natural products with anti-leukemia capabilities.

Distribution of monocytes subpopulations in the peripheral blood from patients with Behçet's disease - Impact of disease status and colchicine use.

The innate immune response has a predominant role in Behçet's disease (BD) pathogenesis, but few studies have assessed monocytes in BD. This study aims to evaluate the profile of monocytes subsets in the peripheral blood of BD patients and healthy controls (HC). Monocytes subsets were identified as classical (CD14+CD16-), intermediate (CD14+CD16dim), and non-classical (CD14dimCD16high) subsets. Patients with BD presented a lower number of total monocytes (p = 0.020) and a lower number (p < 0.0001) of circulating classical monocytes than HC. In contrast, the number of intermediate monocytes was higher in BD patients than HC (p < 0.0001). In BD patients, no associations were observed with the severity of clinical manifestations or therapy. Colchicine was associated with a higher number of non-classical monocytes (p = 0.035). In conclusion, BD patients present an altered distribution of monocytes subsets with a reduction of classical and an increase of intermediate subsets.

α-amyrin-loaded nanocapsules produce selective cytotoxic activity in leukemic cells.

INTRODUCTION: Amyrins are triterpenes that have attractive pharmacological potential; however, their low water solubility and erratic stomach absorption hinders their use as a drug. The aim of this paper was to develop a novel α-amyrin-loaded nanocapsule for intestinal delivery and evaluate, preliminarily, its cytotoxic ability against leukemic cells. MATERIAL AND METHODS: Five nanocapsule formulations were designed by the solvent displacement-evaporation method. Poly-ε-caprolactone, Eudragit® E100, and Kollicoat® Mae 100 P were used as film-former materials. Particle size, polydispersity index (PdI), zeta potential, and the pH of all formulations were measured. The cytotoxic potential of the nanocapsules was evaluated in vitro using different leukemic lineages RESULTS: Nanocapsules coated with Kollicoat® Mae 100 P presented the smallest particle size (130 nm), the lowest zeta-potential (-38 mV), and the narrowest size distribution (PdI = 0.100). The entrapment efficiency was 65.47%, while the loading capacity was 2.40%. Nanocapsules release 100% of α-amyrin in 40 min (pH 7.4), by using a possible mechanism of swelling-diffusion. The formulation showed excellent on-shelf physicochemical stability during one year. Additionally, nanocapsules produced a selective cytotoxic effect on a human leukemia lineage Kasumi-1, an acute myeloid leukemia cell line, and produced cell death by apoptosis CONCLUSION: α-amyrin-loaded nanocapsules appear to be a promising nanoformulation that could be used against leukemia.

Intermittent hypoxia changes the interaction of the kinin-VEGF system and impairs myocardial angiogenesis in the hypertrophic heart.

Intermittent hypoxia (IH) is a feature of obstructive sleep apnea (OSA), a condition highly associated with hypertension-related cardiovascular diseases. Repeated episodes of IH contribute to imbalance of angiogenic growth factors in the hypertrophic heart, which is key in the progression of cardiovascular complications. In particular, the interaction between vascular endothelial growth factor (VEGF) and the kallikrein-kinin system (KKS) is essential for promoting angiogenesis. However, researchers have yet to investigate experimental models of IH that reproduce OSA, myocardial angiogenesis, and expression of KKS components. We examined temporal changes in cardiac angiogenesis in a mouse IH model. Adult male C57BI/6 J mice were implanted with Matrigel plugs and subjected to IH for 1-5 weeks with subsequent weekly histological evaluation of vascularization. Expression of VEGF and KKS components was also evaluated. After 3 weeks, in vivo myocardial angiogenesis and capillary density were decreased, accompanied by a late increase of VEGF and its type 2 receptor. Furthermore, IH increased left ventricular myocardium expression of the B2 bradykinin receptor, while reducing mRNA levels of B1 receptor. These results suggest that in IH, an unexpected response of the VEGF and KKS systems could explain the reduced capillary density and impaired angiogenesis in the hypoxic heart, with potential implications in hypertrophic heart malfunction.

Angiotensin II modulates the murine hematopoietic stem cell and progenitors cocultured with stromal S17 cells.

Although the existence of the renin-angiotensin system (RAS) in the bone marrow is clear, the exact role of this system in hematopoiesis has not yet been fully characterized. Here the direct role of angiotensin II (AngII) in hematopoietic stem cells (HSCs), common myeloid progenitors (CMPs), granulocyte/monocyte progenitors (GMPs), and megakaryocytes/erythroid progenitors (MEPs), using a system of coculture with stromal S17 cells. Flow cytometry analysis showed that AngII increases the percentage of HSC and GMP, while reducing CMP with no effect on MEP. According to these data, AngII increased the total number of mature Gr-1+ /Mac-1+ cells without changes in Terr119+ cells. AngII does not induce cell death in the population of LSK cells. In these populations, treatment with AngII decreases the expression of Ki67+ protein with no changes in the Notch1 expression, suggesting a role for AngII on the quiescence of immature cells. In addition, exposure to AngII from murine bone marrow cells increased the number of CFU-GM and BFU-E in a clonogenic assay. In conclusion, our data showed that AngII is involved in the regulation of hematopoiesis with a special role in HSC, suggesting that AngII should be evaluated in coculture systems, especially in cases that require the expansion of these cells in vitro, still a significant challenge for therapeutic applications in humans.

A styrylpyrone dimer isolated from Aniba heringeri causes apoptosis in MDA-MB-231 triple-negative breast cancer cells.

The styrylpyrone dehydrogoniothalamin (1) and two of its dimers (2 and 3) were isolated from the leaves of Aniba heringeri (Lauraceae). Compound 3 is new, while 1 and 2 are being reported for the first time in this species. Structures were determined by 1D- and 2D-NMR spectroscopy, mass spectrometry, and optical rotation data. Cytotoxic effects and selectivity indices were evaluated in five neoplastic cell lines-PC-3 (prostate), 786-0 (renal), HT-29 (colon), MCF-7, and MDA-MB-231 (breast)-and a non-neoplastic cell line, (NIH/3T3, murine fibroblast). Compound 1 inhibited cell growth by 50% (GI50) at concentrations in the 90.4-175.7 µM range, while 2 proved active against MCF-7 and MDA-MB-231 breast cells (GI50 = 12.24, and 34.22 µM, respectively). Compound 3 showed strong cytotoxicity (GI50 = 4.4 µM) against MDA-MB-231 (an established basal triple-negative breast carcinoma (TNBC) cell line), with a high selective index of 35. This compound was subsequently evaluated for apoptosis induction in MDA-MB-231 cells, using GI50 and 50% lethal concentrations (LC50). Flow cytometry analysis showed that at LC50 compound 3 induced cell death with phosphatidylserine externalization and caspase-3 activation. Apoptotic genes were measured by RT-qPCR, revealing an upregulation of BAX, with an increase in expression of the BAX/BCL2 ratio in treated cells. Fluorescence microscopy disclosed morphological changes related to apoptosis. Overall, these findings showed compound 3 to be a promising prototype against TNBC cells that tend to respond poorly to conventional therapies.