Insuela DBR, Azevedo CT, Coutinho DS, Magalhães NS, Ferrero MR, Ferreira TPT, Cascabulho CM, Henriques-Pons A, Olsen PC, Diaz BL, Silva PMR, Cordeiro RSB, Martins MA, Carvalho VF. Glucagon reduces airway hyperreactivity, inflammation, and remodeling induced by ovalbumin. Sci Rep. 2019 Apr 24;9(1):6478. 

DOI: 10.1038/s41598-019-42981-6

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Glucagon has been shown to be beneficial as a treatment for bronchospasm in asthmatics. Here, we investigate if glucagon would prevent airway hyperreactivity (AHR), lung inflammation, and remodeling in a murine model of asthma. Glucagon (10 and 100 µg/Kg, i.n.) significantly prevented AHR and eosinophilia in BAL and peribronchiolar region induced by ovalbumin (OVA) challenge, while only the dose of 100 µg/Kg of glucagon inhibited subepithelial fibrosis and T lymphocytes accumulation in BAL and lung. The inhibitory action of glucagon occurred in parallel with reduction of OVA-induced generation of IL-4, IL-5, IL-13, TNF-α, eotaxin-1/CCL11, and eotaxin-2/CCL24 but not MDC/CCL22 and TARC/CCL17. The inhibitory effect of glucagon (100 µg/Kg, i.n.) on OVA-induced AHR and collagen deposition was reversed by pre-treatment with indomethacin (10 mg/Kg, i.p.). Glucagon increased intracellular cAMP levels and inhibits anti-CD3 plus anti-CD28-induced proliferation and production of IL-2, IL-4, IL-10, and TNF- α from TCD4+ cells in vitro. These findings suggest that glucagon reduces crucial features of asthma, including AHR, lung inflammation, and remodeling, in a mechanism probably associated with inhibition of eosinophils accumulation and TCD4+ cell proliferation and function. Glucagon should be further investigated as an option for asthma therapy.

de Oliveira GP, Kitoko JZ, de Souza Lima-Gomes P, Rochael NC, de Araújo CC, Lugon PN, Dos Santos HL, Martins EGL, Ornellas FM, de Oliveira HD, Morales MM, Olsen PC, Galina A, Silva PL, Saraiva EM, Pelosi P, Rocco PRM. Glutamine Therapy Reduces Inflammation and Extracellular Trap Release in Experimental Acute Respiratory Distress Syndrome of Pulmonary Origin. Nutrients. 2019 Apr 12;11(4):831.

DOI: 10.3390/nu11040831

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The innate immune response plays an important role in the pathophysiology of acute respiratory distress syndrome (ARDS). Glutamine (Gln) decreases lung inflammation in experimental ARDS, but its impact on the formation of extracellular traps (ETs) in the lung is unknown. In a mouse model of endotoxin-induced pulmonary ARDS, the effects of Gln treatment on leukocyte counts and ET content in bronchoalveolar lavage fluid (BALF), inflammatory profile in lung tissue, and lung morphofunction were evaluated in vivo. Furthermore, ET formation, reactive oxygen species (ROS) production, glutathione peroxidase (GPx), and glutathione reductase (GR) activities were tested in vitro. Our in vivo results demonstrated that Gln treatment reduced ET release (as indicated by cell-free-DNA content and myeloperoxidase activity), decreased lung inflammation (reductions in interferon-γ and increases in interleukin-10 levels), and improved lung morpho-function (decreased static lung elastance and alveolar collapse) in comparison with ARDS animals treated with saline. Moreover, Gln reduced ET and ROS formation in BALF cells stimulated with lipopolysaccharide in vitro, but it did not alter GPx or GR activity. In this model of endotoxin-induced pulmonary ARDS, treatment with Gln reduced pulmonary functional and morphological impairment, inflammation, and ET release in the lung.

Chaves OA, de Castro IS, Goulart CM, Bellieny MSS, Netto-Ferreira JC, Echevarria-Lima J, Echevarria A. In vitro and in vivo cytotoxic activity and human serum albumin interaction for a methoxy-styryl-thiosemicarbazone. Invest New Drugs. 2019 Oct;37(5):994-1005.

DOI: 10.1007/s10637-018-00722-y

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Thiosemicarbazone is a class of compounds with potential applications in medicine, presenting high capacity to inhibit the growth of cancer cells as well as low toxicity. Because of high interest in anticancer studies involving thiosemicarbazones as new chemotherapeutic agents, a synthetic thiosemicarbazone derivative, 4-N-(2′-methoxy-styryl)-thiosemicarbazone (MTSC) was evaluated in vivo against Ehrlich carcinoma in an animal model. In vivo results demonstrated that MTSC treatment induced the survival of mice and altered significantly the body weight of the surviving mice 12 days after tumor inoculation. Treatment with 30 mg/kg of MTSC exhibited effective cytotoxic activity with T/C values of 150.49% (1 dose) and 278% (2 doses). Its interaction with human serum albumin (HSA), which plays a crucial role in the biodistribution of a wide variety of ligands, was investigated by multiple spectroscopic techniques at 296 K, 303 K, and 310 K, as well as by theoretical calculations. The interaction between HSA and MTSC occurs via ground-state association in the subdomain IIA (Sudlow’s site I). The binding is moderate (Ka ≈ 104 M–1), spontaneous, entropically, and enthalpically driven. Molecular docking results suggested hydrogen bonding and hydrophobic interactions as the main binding forces. Overall, the interaction HSA:MTSC could provide therapeutic benefits, improving its cytotoxic efficacy and tolerability.

da Fonseca-Martins AM, Ramos TD, Pratti JES, Firmino-Cruz L, Gomes DCO, Soong L, Saraiva EM, de Matos Guedes HL. Immunotherapy using anti-PD-1 and anti-PD-L1 in Leishmania amazonensis-infected BALB/c mice reduce parasite load. Sci Rep. 2019 Dec 30;9(1):20275. 

DOI: 10.1038/s41598-019-56336-8

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Leishmaniasis is a neglected disease, for which current treatment presents numerous issues. Leishmania amazonensis is the etiological agent of cutaneous and diffuse cutaneous leishmaniasis. The roles of the programmed death-1 (PD-1) receptor on lymphocytes and its ligand (PD-L1) on antigen-presenting cells have been well studied in tumor and other infection models; but little is known about their roles in non-healing cutaneous leishmaniasis. In this study, we observed that L. amazonensis induced PD-1 expression on both CD4+ and CD8+ T cells and PD-L1 on dendritic cells on BALB/c mice. We tested the therapeutic potential of anti-PD-1 and anti-PD-L1 monoclonal antibodies (MoAbs) against a non-healing L. amazonensis infection in BALB/c mice, and that anti-PD-1 and anti-PD-L1 treatment significantly increased IFN-γ-producing CD4+ and CD8+ T cells, respectively. Compared with infection controls, mice treated with anti-PD-1 and anti-PD-L1, but not anti-PD-L2, displayed bigger lesions with significantly lower parasite loads. Treatment did not affect anti-Leishmania antibody (IgM, IgG, IgG1 and IgG2a) or IL-10 production, but anti-PD-1 treatment reduced both IL-4 and TGF-β production. Together, our results highlight the therapeutic potential of an anti-PD-1-based treatment in promoting the reinvigoration of T cells for the control of parasite burden.

Luz NF, DeSouza-Vieira T, De Castro W, Vivarini AC, Pereira L, França RR, Silveira-Mattos PS, Costa DL, Teixeira C, Meneses C, Boaventura VS, de Oliveira CI, Lopes UG, Aronson N, Andrade BB, Brodskyn CI, Valenzuela JG, Kamhawi S, Borges VM. Lutzomyia longipalpis Saliva Induces Heme Oxygenase-1 Expression at Bite Sites. Front Immunol. 2018 Nov 28;9:2779.  

DOI: 10.3389/fimmu.2018.02779

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Sand flies bite mammalian hosts to obtain a blood meal, driving changes in the host inflammatory response that support the establishment of Leishmania infection. This effect is partially attributed to components of sand fly saliva, which are able to recruit and activate leukocytes. Our group has shown that heme oxygenase-1 (HO-1) favors Leishmania survival in infected cells by reducing inflammatory responses. Here, we show that exposure to sand fly bites is associated with induction of HO-1 in vivo. Histopathological analyses of skin specimens from human volunteers experimentally exposed to sand fly bites revealed that HO-1 and Nrf2 are produced at bite sites in the skin. These results were recapitulated in mice ears injected with a salivary gland sonicate (SGS) or exposed to sand fly bites, indicating that vector saliva may be a key factor in triggering HO-1 expression. Resident skin macrophages were the main source HO-1 at 24–48 h after bites. Additionally, assays in vivo after bites and in vitro after stimulation with saliva both demonstrated that HO-1 production by macrophages was Nrf2-dependent. Collectively, our data demonstrates that vector saliva induces early HO-1 production at the bite sites, representing a major event associated with establishment of naturally-transmitted Leishmania infections.

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