Biological characteristics of the Trypanosoma cruzi Arequipa strain make it a good model for Chagas disease drug discovery

Trypanosoma cruzi, the causative agent of Chagas disease (CD), is a genuine parasite with tremendous genetic diversity and a complex life cycle. Scientists have studied this disease for more than 100 years, and CD drug discovery has been a mainstay due to the absence of an effective treatment. Technical advances in several areas have contributed to a better understanding of the complex biology and life cycle of this parasite, with the aim of designing the ideal profile of both drug and therapeutic options to treat CD. Here, we present the T. cruzi Arequipa strain (MHOM/Pe/2011/Arequipa) as an interesting model for CD drug discovery. We characterized acutephase parasitaemia and chronic-phase tropism in BALB/c mice and determined the in vitro and in vivo benznidazole susceptibility profile of the different morphological forms of this strain. The tropism of this strain makes it an interesting model for the screening of new compounds with a potential anti-Chagas profile for the treatment of this disease.Alfonso Martin Escudero Foundation Junta de Andalucia A-CTS-383-UGR1

Identification of Aryl Polyamines Derivatives as Anti-Trypanosoma cruzi Agents Targeting Iron Superoxide Dismutase

Chagas disease (CD) is a tropical and potentially fatal infection caused by Trypanosoma cruzi. Although CD was limited to Latin America as a silent disease, CD has become widespread as a result of globalization. Currently, 6–8 million people are infected worldwide, and no effective treatment is available. Here, we identify new effective agents against T. cruzi. In short, 16 aryl polyamines were screened in vitro against different T. cruzi strains, and lead compounds were evaluated in vivo after oral administration in both the acute and chronic infections. The mode of action was also evaluated at the energetic level, and its high activity profile could be ascribed to a mitochondria-dependent bioenergetic collapse and redox stress by inhibition of the Fe-SOD enzyme. We present compound 15 as a potential compound that provides a step forward for the development of new agents to combat CD.Ministerio de Economia, Industria y Competitividad (CONSOLIDER CSD2010–00065 and CTQ2017–90852-REDC)MINECO and FEDER funds from the EU (Projects PID2019-110751RB-I00, RED2018-102331-T and Unidad de Excelencia María de Maeztu CEX2019-000919-M)Alfonso Martín Escudero Foundatio

Selenium Derivatives as Promising Therapy for Chagas Disease: In Vitro and In Vivo Studies

This work was financially supported by the Ministerio de Economia, Industria y Competitividad (CONSOLIDER CSD2010-00065 and CTQ2017-90852-REDC). R.M.-E. is grateful for the fellowship from the Alfonso Martin Escudero Foundation.Chagas disease is a tropical infection caused by the protozoan parasite Trypanosoma cruzi and a global public health concern. It is a paradigmatic example of a chronic disease without an effective treatment. Current treatments targeting T. cruzi are limited to two obsolete nitroheterocyclic drugs, benznidazole and nifurtimox, which lead to serious drawbacks. Hence, new, more effective, safer, and affordable drugs are urgently needed. Selenium and their derivatives have emerged as an interesting strategy for the treatment of different prozotoan diseases, such as African trypanosomiasis, leishmaniasis, and malaria. In the case of Chagas disease, diverse selenium scaffolds have been reported with antichagasic activity in vitro and in vivo. On the basis of these premises, we describe the in vitro and in vivo trypanocidal activity of 41 selenocompounds against the three morphological forms of different T. cruzi strains. For the most active selenocompounds, their effect on the metabolic and mitochondrial levels and superoxide dismutase enzyme inhibition capacity were measured in order to determine the possible mechanism of action. Derivative 26, with a selenocyanate motif, fulfills the most stringent in vitro requirements for potential antichagasic agents and exhibits a better profile than benznidazole in vivo. This finding provides a step forward for the development of a new antichagasic agent.Spanish Government CONSOLIDER CSD2010-00065 CTQ2017-90852-REDCAlfonso Martin Escudero Foundatio

Library of Selenocyanate and Diselenide Derivatives as In Vivo Antichagasic Compounds Targeting Trypanosoma Cruzi Mitochondrion

Chagas disease is usually caused by tropical infection with the insect-transmitted protozoan Trypanosoma cruzi. Currently, Chagas disease is a major public health concern worldwide due to globalization, and there are no treatments neither vaccines because of the long-term nature of the disease and its complex pathology. Current treatments are limited to two obsolete drugs, benznidazole and nifurtimox, which lead to serious drawbacks. Taking into account the urgent need for strict research efforts to find new therapies, here, we describe the in vitro and in vivo trypanocidal activity of a library of selected forty-eight selenocyanate and diselenide derivatives that exhibited leishmanicidal properties. The inclusion of selenium, an essential trace element, was due to the wellknown extensive pharmacological activities for selenium compounds including parasitic diseases as T. cruzi. Here we present compound 8 as a potential compound that exhibits a better profile than benznidazole both in vitro and in vivo. It shows a fast-acting behaviour that could be attributed to its mode of action: it acts in a mitochondrion-dependent manner, causing cell death by bioenergetic collapse. This finding provides a step forward for the development of a new antichagasic agent.Ministerio de Economia, Industria y Competitividad, grant number CSD2010–00065 and CTQ2017–90852-REDCConserjería de Economía, Conocimiento, Empresas y Universidad de la Junta de Andalucia, grant number A-CTS-383-UGR18Institute of Tropical Health of University of Navarre (ISTUN)Caixa FoundationRoviralta and UbesolAlfonso Martín Escudero Foundatio

Effective Tetradentate Compound Complexes against Leishmania spp. that Act on Critical Enzymatic Pathways of These Parasites

The spectrum and efficacy of available antileishmanial drugs is limited. In the present work we evaluated in vitro the antiproliferative activity of 11 compounds based on tetradentate polyamines compounds against three Leishmania species (L. braziliensis, L. donovani and L. infantum) and the possible mechanism of action. We identified six compounds (3, 5, 6, 7, 8 and 10) effective against all three Leishmania spp both on extracellular and intracellular forms. These six most active leishmanicidal compounds also prevent the infection of host cells. Nevertheless, only compound 7 is targeted against the Leishmania SOD. Meanwhile, on the glucose metabolism the tested compounds have a species-specific effect on Leishmania spp.: L. braziliensis was affected mainly by 10 and 8, L. donovani by 7, and L. infantum by 5 and 3. Finally, the cellular ultrastructure was mainly damaged by 11 in the three Leishmania spp. studied. These identified antileishmania candidates constitute a good alternative treatment and will be further studied.This research was funded by THE SPANISH MINISTRY OF ECONOMY AND COMPETITIVENESS (MINECO), CONSOLIDER-INGENIO 2010, grant number CDS2010-00065; THE EUROPEAN RESEARCH FOUNDATION, grant number ERC-2009-StG-239910; THE MICINN, grant number CTQ2009-08464; and INNPLANTA, grant number INP-2011-0059-PCT-420000-ACT1

Preclinical studies of toxicity and safety of the AS-48 bacteriocin

The in vitro antimicrobial potency of the bacteriocin AS-48 is well documented, but its clinical application requires investigation, as its toxicity could be different in in vitro (haemolytic and antibacterial activity in blood and cytotoxicity towards normal human cell lines) and in vivo (e.g. mice and zebrafish embryos) models. Overall, the results obtained are promising. They reveal the negligible propensity of AS-48 to cause cell death or impede cell growth at therapeutic concentrations and support the suitability of this peptide as a potential therapeutic agent against several microbial infections, due to its selectivity and potency at low concentrations. In addition, AS-48 exhibits low haemolytic activity in whole blood and does not induce nitrite accumulation in non-stimulated RAW macrophages, indicating a lack of pro-inflammatory effects. The unexpected heightened sensitivity of zebrafish embryos to AS-48 could be due to the low differentiation state of these cells. The low cytotoxicity of AS-48, the absence of lymphocyte proliferation in vivo after skin sensitization in mice, and the lack of toxicity in a murine model support the consideration of the broad spectrum antimicrobial peptideThis research was funded by the Spanish Ministry of Economy and Competitiveness (SAF2013-48971-C2-1-R, CSD2010-00065, and AGL2015-67995-C3-3-R, all including funds from the European Regional Development Funding, ERDF) and by the Research Groups (BIO160, CTS 944 and CTS 164, UGR) from Junta de Andalucía (Spain). The CIBER-EHD is funded by the Instituto de Salud Carlos III. RM-E is grateful for an FPU Grant (FPU14/01537) from the Ministry of Education, (Spain)

Tetradentate polyamines as efficient metallodrugs for Chagas disease treatment in murine model.

A series of tetraamine-based compounds was prepared, and their trypanocidal effects against Trypanosoma cruzi and cytotoxicity were determined through the determination of IC50 values. In vivo assays were performed in mice, where parasitaemia levels were quantified by fresh blood examination and the assignment of a cure was determined by polymerase chain reaction and reactivation of blood parasitaemia levels after immunosuppression. The mechanisms of action were elucidated at metabolic and ultra-structural levels, by 1H NMR, Fe-SOD inhibition and TEM studies. The high-selectivity indexes observed in vitro were the basis of promoting one of the tested compounds to in vivo assays. Compound 6 induced a remarkable decrease in the reactivation of parasitaemia after immunosuppression and curative rates of 33%. The experiments allowed us to select compound 6 as a promising candidate for treating Chagas disease, but a further high-level study should be considered to obtain an improved efficiency

A Zn2+-triggered two-step mechanism of CLIC1 membrane insertion and activation into chloride channels

The chloride intracellular channel (CLIC) protein family displays the unique feature of altering its structure from a soluble form to a membrane-bound chloride channel. CLIC1, a member of this family, is found in the cytoplasm or in internal and plasma membranes, with membrane relocalisation linked to endothelial disfunction, tumour proliferation and metastasis. The molecular switch promoting CLIC1 activation remains under investigation. Here, cellular Cl− efflux assays and immunofluorescence microscopy studies have identified intracellular Zn2+ release as the trigger for CLIC1 activation and membrane insertion. Biophysical assays confirmed specific binding to Zn2+, inducing membrane association and enhancing Cl− efflux in a pH-dependent manner. Together, our results identify a two- step mechanism with Zn2+ binding as the molecular switch promoting CLIC1 membrane insertion, followed by pH-mediated activation of Cl− efflux

Immunological and senescence biomarker profiles in patients after spontaneous clearance of hepatitis C virus: gender implications for long-term health risk

Background: About 25% of patients with acute hepatitis C virus (HCV) infection show spontaneous clearance within the first six months of infection but may remain at risk of inflammaging, aging, and liver and non-liver disease complications. This study evaluated the differences in the plasma levels of immune checkpoints (ICs) and senescence-associated secretory phenotype (SASP) biomarkers between patients who had spontaneously eliminated HCV infection (SC group) and individuals without evidence of HCV infection (C group). Methods: We performed a multicenter retrospective study of 56 individuals: 32 in the SC and 24 in the C groups. ICs and SASP proteins were analyzed using a Luminex 200TM analyzer. The statistical analysis used Generalized Linear Models with gamma distribution (log-link) adjusted by significant variables and sex. Results: 13 ICs (BTLA, CD137(4-1BB), CD27, CD28, CD80, GITR, HVEM, IDO, LAG-3, PD-1, PD-L1, PD-L2, and TIM-3) and 13 SASP proteins (EGF, Eotaxin, IL-1alpha, IL-1RA, IL-8, IL-13, IL-18, IP-10, SDF-1alpha, HGF, beta-NGF, PLGF-1, and SCF) were significantly higher in SC group after approximately more than two years of HCV clearance. After stratifying by sex, differences remained significant for males, which showed higher levels for 13 ICs and 4 SASP proteins in SC. While only PD-L2 was significantly higher in SC women, and no differences in SASP were found. Conclusions: Higher plasma levels of different IC and SASP proteins were found in individuals after more than two years of HCV clearance, mainly in men. Alterations in these molecules might be associated with an increased risk of developing liver and non-hepatic diseases.This study was supported by grants from Instituto de Salud Carlos III (ISCIII; grant number CP14/0010) to AFR), Fundación Universidad Alfonso X el Sabio (FUAX) – Santander (grant number 1.010.932 to AFR) and by PID2021–126781OB-I00 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”. The study was also funded by the CIBER -Consorcio Centro de Investigación Biomédica en Red- (CB 2021), Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación and Unión Europea–Next‑GenerationEU (CB21/13/00044, CB21/13/00118, and GVC16/EHD/4). M.A.J.-S. is Miguel Servet researcher supported and funded by ISCIII (grant numbers CP17CIII/00007). RME is Juan de la Cierva researcher supported and fnanced by MICINN of Spain (FJC2020-042865-I).S

Additional file 1 of Immunological and senescence biomarker profiles in patients after spontaneous clearance of hepatitis C virus: gender implications for long-term health risk

Additional file 1. Biochemical characteristics of 56 individuals stratified by HCV infection status and sex.Ministerio de Ciencia e Innovación; Consorcio Centro de Investigación Biomédica en Red; Instituto de Salud Carlos III; Fundación Universidad Alfonso X el SabioPeer reviewe