RESUMEN

Metacaspases are a distinct class of cysteine proteases predominantly found in plants, fungi, and protozoa, crucial for regulating programmed cell death (PCD). They possess unique structural features and differ markedly from caspases in their activation mechanisms and substrate specificities, with a notable preference for binding basic residues in substrates. In this study, we introduced vanillin-derived oximic compounds to explore their pharmaceutical potential. We evaluated these compounds for their inhibitory effects on TbMCA2, a metacaspase in Trypanosoma brucei, identifying AO-7, AO-12, and EO-20 as promising inhibitors. AO-12 showed significant potential as a non-competitive inhibitor with notable IC50 values. Molecular docking studies were also conducted to evaluate the binding affinity of these compounds for TbMCA2. This research is particularly relevant given the urgent need for more effective and less toxic treatments for trypanosomiasis, a parasitic disease caused by trypanosomes. The absence of available vaccines and the limitations imposed by drug toxicity underscore the importance of these findings. Our study represents a significant advancement in developing therapeutic agents targeting metacaspases in trypanosomatids and highlights the necessity of understanding metacaspase regulation across various species. It provides valuable insights into inhibitor sensitivity and potential species-specific therapeutic strategies. In conclusion, this research opens promising avenues for novel therapeutic agents targeting metacaspases in trypanosomatids, addressing a critical gap in combating neglected diseases associated with these pathogens. Further research is essential to refine the efficacy and safety profiles of these compounds, aiming to deliver more accessible and effective therapeutic solutions to populations afflicted by these debilitating diseases.

Asunto(s)

Caspasas , Simulación del Acoplamiento Molecular , Trypanosoma brucei brucei , Trypanosoma brucei brucei/enzimología , Trypanosoma brucei brucei/efectos de los fármacos , Caspasas/metabolismo , Caspasas/química , Inhibidores de Caspasas/farmacología , Inhibidores de Caspasas/química , Benzaldehídos/farmacología , Benzaldehídos/química , Proteínas Protozoarias/antagonistas & inhibidores , Proteínas Protozoarias/metabolismo , Proteínas Protozoarias/química , Tripanocidas/farmacología , Tripanocidas/química

RESUMEN

Experiments conducted on triple-negative breast cancer have shown that fucoidan from Lessonia trabeculata (FLt) exhibits cytotoxic and antitumor properties. However, further research is necessary to gain a complete understanding of its bioactivity and level of cytotoxicity. The cytotoxic effect of FLt was determined by the 2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Apoptosis was analyzed using annexin V and caspase 3/7 staining kit and DNA fragmentation. In addition, transcriptional expression of antiapoptotic (Bcl-2 and XIAP) and proapoptotic (caspase 8, caspase 9, and AIF) genes were analyzed in TNBC 4T1 cells. After 72 h of culture, the IC50 for FLt was 561 µg/mL, while doxorubicin (Dox) had an IC50 of 0.04 µg/mL. In addition, assays for FLt + Dox were performed. Annexin V and caspase 3/7 revealed that FLt induces early and late-stage apoptosis. DNA fragmentation results support necrotic death of 4T1 cells. Similarly, transcripts that prevent cell death were decreased, while transcripts that promote cell death were increased. This study showed that FLt induces apoptosis by both caspase-dependent and caspase-independent mechanisms. These findings suggest that FLt may have potential applications in breast cancer treatment. Further research will provide more information to elucidate the mechanism of action of FLt.

Asunto(s)

Apoptosis , Caspasas , Polisacáridos , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Polisacáridos/farmacología , Animales , Femenino , Caspasas/metabolismo , Ratones , Antineoplásicos/farmacología , Doxorrubicina/farmacología , Humanos , Adenocarcinoma/tratamiento farmacológico , Adenocarcinoma/patología , Fragmentación del ADN/efectos de los fármacos , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Neoplasias de la Mama Triple Negativas/patología , Kelp

RESUMEN

The protein scaffold that includes the caspases is ancient and found in all domains of life. However, the stringent specificity that defines the caspase biologic function is relatively recent and found only in multicellular animals. During the radiation of the Chordata, members of the caspase family adopted roles in immunity, events coinciding with the development of substrates that define the modern innate immune response. This review focuses on the switch from the non-inflammatory cellular demise of apoptosis to the highly inflammatory innate response driven by distinct members of the caspase family, and the interplay between these two regulated cell death pathways.

Asunto(s)

Caspasas , Inmunidad Innata , Piroptosis , Humanos , Caspasas/metabolismo , Animales , Evolución Molecular , Apoptosis

RESUMEN

BACKGROUND: Inflammation in adipose tissue, resulting from imbalanced caloric intake and energy expenditure, contributes to the metabolic dysregulation observed in obesity. The production of inflammatory cytokines, such as IL-1ß and IL-18, plays a key role in this process. While IL-1ß promotes insulin resistance and diabetes, IL-18 regulates energy expenditure and food intake. Previous studies have suggested that caspase-1, activated by the Nlrp3 inflammasome in response to lipid excess, mediates IL-1ß production, whereas activated by the Nlrp1b inflammasome in response to energy excess, mediates IL-18 production. However, this has not been formally tested. METHODS: Wild-type and caspase-1-deficient Balb/c mice, carrying the Nlrp1b1 allele, were fed with regular chow or a high-fat diet for twelve weeks. Food intake and mass gain were recorded weekly. At the end of the twelve weeks, glucose tolerance and insulin resistance were evaluated. Mature IL-18 protein levels and the inflammatory process in the adipose tissue were determined. Fasting lipid and cytokine levels were quantified in the sera of the different experimental groups. RESULTS: We found that IL-18 production in adipose tissue is independent of caspase-1 activity, regardless of the metabolic state, while Nlrp3-mediated IL-1ß production remains caspase-1 dependent. Additionally, caspase-1 null Balb/c mice did not develop metabolic abnormalities in response to energy excess from the high-fat diet. CONCLUSION: Our findings suggest that IL-18 production in the adipose tissue is independent of Nlrp3 inflammasome and caspase-1 activation, regardless of caloric food intake. In contrast, Nlrp3-mediated IL-1ß production is caspase-1 dependent. These results provide new insights into the mechanisms underlying cytokine production in the adipose tissue during both homeostatic conditions and metabolic stress, highlighting the distinct roles of caspase-1 and the Nlrp inflammasomes in regulating inflammatory responses.

Asunto(s)

Tejido Adiposo , Caspasa 1 , Caspasas Iniciadoras , Interleucina-18 , Proteína con Dominio Pirina 3 de la Familia NLR , Animales , Ratones , Tejido Adiposo/metabolismo , Caspasa 1/metabolismo , Caspasas/metabolismo , Citocinas/metabolismo , Inflamasomas/metabolismo , Resistencia a la Insulina , Interleucina-18/metabolismo , Lípidos , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Caspasas Iniciadoras/metabolismo

RESUMEN

BACKGROUND: Metacaspases comprise a family of cysteine proteases implicated in both cell death and cell differentiation of protists that has been considered a potential drug target for protozoan parasites. However, the biology of metacaspases in Plasmodium vivax - the second most prevalent and most widespread human malaria parasite worldwide, whose occurrence of chemoresistance has been reported in many endemic countries, remains largely unexplored. Therefore, the present study aimed to address, for the first time, the expression pattern of metacaspases in P. vivax parasites. METHODS AND RESULTS: P. vivax blood-stage parasites were obtained from malaria patients in the Brazilian Amazon and the expression of the three putative P. vivax metacaspases (PvMCA1-3) was detected in all isolates by quantitative PCR assay. Of note, the expression levels of each PvMCA varied noticeably across isolates, which presented different frequencies of parasite forms, supporting that PvMCAs may be expressed in a stage-specific manner as previously shown in P. falciparum. CONCLUSION: The detection of metacaspases in P. vivax blood-stage parasites reported herein, allows the inclusion of these proteases as a potential candidate drug target for vivax malaria, while further investigations are still required to evaluate the activity, role and essentiality of metacaspases in P. vivax biology.

Asunto(s)

Malaria Vivax , Plasmodium vivax , Proteínas Protozoarias , Plasmodium vivax/genética , Plasmodium vivax/aislamiento & purificación , Brasil , Humanos , Malaria Vivax/parasitología , Proteínas Protozoarias/genética , Proteínas Protozoarias/metabolismo , Caspasas/genética , Caspasas/metabolismo , Expresión Génica/genética

RESUMEN

Metacaspases are cysteine proteases belonging to the CD clan of the C14 family. They possess important characteristics, such as specificity for cleavage after basic residues (Arg/Lys) and dependence on calcium ions to exert their catalytic activity. They are defined by the presence of a large subunit (p20) and a small subunit (p10) and are classified into types I, II, and III. Type I metacaspases have a characteristic pro-domain at the N-terminal of the enzyme, preceding a region rich in glutamine and asparagine. In the yeast Saccharomyces cerevisiae, a type I metacaspase is found. This organism encodes a single metacaspase that participates in the process of programmed cell death by apoptosis. The study focuses on cloning, expressing, and mutating Saccharomyces cerevisiae metacaspase (ScMCA-Ia). Mutations in Cys155 and Cys276 were introduced to investigate autoprocessing mechanisms. Results revealed that Cys155 plays a crucial role in autoprocessing, initiating a conformational change that activates ScMCA-Ia. Comparative analysis with TbMCA-IIa highlighted the significance of the N-terminal region in substrate access to the active site. The study proposes a two-step processing mechanism for type I metacaspases, where an initial processing step generates the active form, followed by a distinct intermolecular processing step. This provides new insights into ScMCA-Ia's activation and function. The findings hold potential implications for understanding cellular processes regulated by metacaspases. Overall, this research significantly advances knowledge in metacaspase biology.

Asunto(s)

Caspasas , Saccharomyces cerevisiae , Caspasas/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Cisteína/genética , Apoptosis , Dominio Catalítico

RESUMEN

The NLRP3, one of the most heavily studied inflammasome-related proteins in mammals, remains inadequately characterized in Atlantic salmon (Salmo salar), despite the significant commercial importance of this salmonid. The NLRP3 inflammasome is composed of the NLRP3 protein, which is associated with procaspase-1 via an adapter molecule known as ASC. This work aims to characterize the Salmo salar NLRP3 inflammasome through in silico structural modeling, functional transcript expression determination in the SHK-1 cell line in vitro, and a transcriptome analysis on Atlantic salmon. The molecular docking results suggested a similar arrangement of the ternary complex between NLRP3, ASC, and caspase-1 in both the Atlantic salmon and the mammalian NLRP3 inflammasomes. Moreover, the expression results confirmed the functionality of the SsNLRP3 inflammasome in the SHK-1 cells, as evidenced by the lipopolysaccharide-induced increase in the transcription of genes involved in inflammasome activation, including ASC and NLRP3. Additionally, the transcriptome results revealed that most of the inflammasome-related genes, including ASC, NLRP3, and caspase-1, were down-regulated in the Atlantic salmon following its adaptation to seawater (also known as parr-smolt transformation). This is correlated with a temporary detrimental effected on the immune system. Collectively, these findings offer novel insights into the evolutionarily conserved role of NLRP3.

Asunto(s)

Inflamasomas , Salmo salar , Animales , Inflamasomas/genética , Inflamasomas/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Salmo salar/genética , Salmo salar/metabolismo , Simulación del Acoplamiento Molecular , Perfilación de la Expresión Génica , Caspasas/metabolismo , Transcriptoma , Mamíferos/metabolismo

RESUMEN

Resistance physical exercise has neuroprotective and anti-inflammatory effects on many known diseases and, therefore, it has been increasingly explored. The way in which this type of exercise exerts these actions is still under investigation. In this study, we aimed to analyze the enzymes and components of the purinergic system involved in the inflammatory process triggered by the P2X7R. Rats were divided into four groups: control, exercise (EX), lipopolysaccharide (LPS), and EX + LPS. The animals in the exercise groups were subjected to a 12-week ladder-climbing resistance physical exercise and received LPS after the last session for sepsis induction. Enzymes activities (NTPDase, 5'-nucleotidase, and adenosine deaminase), purinoceptors' density (P2X7R, A1, and A2A), and the levels of inflammatory indicators (pyrin domain-containing protein 3 (NLRP3), Caspase-1, interleukin (IL)- 6, IL-1B, and tumor necrosis factor (TNF) -α) were measured in the cortex and hippocampus of the animals. The results show that exercise prevented (in the both structures) the increase of: 1) nucleoside-triphosphatase (NTPDase) and 5'-nucleotidase activities; 2) P2X7R density; 3) NLRP3 and Caspase-1; and 4) IL-6, IL-1ß, and TNF-α It is suggested that the purinergic system and the inflammatory pathway of P2X7R are of fundamental importance and influence the effects of resistance physical exercise on LPS-induced inflammation. Thus, the modulation of the P2X7R by resistance physical exercise offers new avenues for the management of inflammatory-related illnesses.

Asunto(s)

Lipopolisacáridos , Proteína con Dominio Pirina 3 de la Familia NLR , Ratas , Animales , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Lipopolisacáridos/toxicidad , 5'-Nucleotidasa/metabolismo , Enfermedades Neuroinflamatorias , Hipocampo/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Interleucina-6/metabolismo , Ejercicio Físico , Caspasas/metabolismo , Receptores Purinérgicos P2X7/metabolismo

RESUMEN

The innate immune response represents the first line of host defense, and it is able to detect pathogen- and damage-associated molecular patterns (PAMPs and DAMPs, respectively) through a variety of pattern recognition receptors (PRRs). Among these PRRs, certain cytosolic receptors of the NLRs family (specifically NLRP1, NLRP3, NLRC4, and NAIP) or those containing at least a pyrin domain (PYD) such as pyrin and AIM2, activate the multimeric complex known as inflammasome, and its effector enzyme caspase-1. The caspase-1 induces the proteolytic maturation of the pro-inflammatory cytokines IL-1ß and IL-18, as well as the pore-forming protein gasdermin D (GSDMD). GSDMD is responsible for the release of the two cytokines and the induction of lytic and inflammatory cell death known as pyroptosis. Each inflammasome receptor detects specific stimuli, either directly or indirectly, thereby enhancing the cell's ability to sense infections or homeostatic disturbances. In this chapter, we present the activation mechanism of the so-called "canonical" inflammasomes.

Asunto(s)

Inmunidad Innata , Inflamasomas , Inflamasomas/metabolismo , Proteínas Portadoras , Citocinas/metabolismo , Caspasas/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo

RESUMEN

The bacillus Calmette-Guérin (BCG) can elicit enhanced innate immune responses against a wide range of infections, known as trained immunity. Brucella abortus is the causative agent of brucellosis, a debilitating disease that affects humans and animals. In this study, we demonstrate that C57BL/6 mouse bone marrow-derived macrophages under BCG training enhance inflammatory responses against B. abortus. BCG-trained macrophages showed increased MHC class II and CD40 expression on the cell surface and higher IL-6, IL-12, and IL-1ß production. The increase in IL-1ß secretion was accompanied by enhanced activation of canonical and noncanonical inflammasome platforms. We observed elevated caspase-11 expression and caspase-1 processing in BCG-trained macrophages in response to B. abortus compared with untrained cells. In addition, these BCG-trained cells showed higher NLRP3 expression after B. abortus infection. From a metabolic point of view, signaling through the Akt/mammalian target of rapamycin/S6 kinase pathway was also enhanced. In addition, BCG training resulted in higher inducible NO synthase expression and nitrite production, culminating in an improved macrophage-killing capacity against intracellular B. abortus. In vivo, we monitored a significant reduction in the bacterial burden in organs from BCG-trained C57BL/6 mice when compared with the untrained group. In addition, previous BCG immunization of RAG-1-deficient mice partially protects against Brucella infection, suggesting the important role of the innate immune compartment in this scenario. Furthermore, naive recipient mice that received BM transfer from BCG-trained donors showed greater resistance to B. abortus when compared with their untrained counterparts. These results demonstrate that BCG-induced trained immunity in mice results in better control of intracellular B. abortus in vivo and in vitro.

Asunto(s)

Brucella abortus , Brucelosis , Humanos , Animales , Ratones , Vacuna BCG , Ratones Endogámicos C57BL , Macrófagos , Brucelosis/metabolismo , Caspasas/metabolismo , Mamíferos

RESUMEN

Tau protein plays a pivotal role in the central nervous system (CNS), participating in microtubule stability, axonal transport, and synaptic communication. Research interest has focused on studying the role of post-translational tau modifications in mitochondrial failure, oxidative damage, and synaptic impairment in Alzheimer's disease (AD). Soluble tau forms produced by its pathological cleaved induced by caspases could lead to neuronal injury contributing to oxidative damage and cognitive decline in AD. For example, the presence of tau cleaved by caspase-3 has been suggested as a relevant factor in AD and is considered a previous event before neurofibrillary tangles (NFTs) formation.Interestingly, we and others have shown that caspase-cleaved tau in N- or C- terminal sites induce mitochondrial bioenergetics defects, axonal transport impairment, neuronal injury, and cognitive decline in neuronal cells and murine models. All these abnormalities are considered relevant in the early neurodegenerative manifestations such as memory and cognitive failure reported in AD. Therefore, in this review, we will discuss for the first time the importance of truncated tau by caspases activation in the pathogenesis of AD and how its negative actions could impact neuronal function.

Asunto(s)

Enfermedad de Alzheimer , Ratones , Humanos , Animales , Enfermedad de Alzheimer/patología , Proteínas tau/metabolismo , Neuronas/metabolismo , Caspasas/metabolismo , Mitocondrias/metabolismo

RESUMEN

Caspases are crucial mediators of programmed cell death (apoptosis). Apoptosis can occur in spermatozoa during spermatogenesis or epididymal transit, as well as in ejaculated spermatozoa. A high proportion of apoptotic sperm would be a poor indicator of the freezability of a raw seminal sample. Alpaca spermatozoa are notoriously difficult to freeze successfully. Therefore, the objectives of this study were to study caspase activation during incubation (37°C) of fresh alpaca spermatozoa, as well as before and after cryopreservation, to gain some insight into the mechanisms behind the vulnerability of alpaca spermatozoa. Eleven sperm samples were incubated for 4 h at 37°C (Study 1), and 23 samples were frozen using an automated system (Study 2). Caspase-3/7 activation was assessed at 0,1,2,3, and 4 h in samples incubated at 37°C (Study 1); and before/after cryopreservation (Study 2) using CellEvent™ Caspase 3/7 Green Detection Reagent and flow cytometry. The proportions of alpaca spermatozoa with caspase-3/7 activated increased (p < 0.05) after 3-4 h of incubation at 37°C; however, caspase activation was similar before and after cryopreservation (36.2 ± 11.2% vs. 36.6 ± 33.7%, p > 0.05). The high standard deviation found after freezing could be explained by the existence of two subpopulations: one subpopulation where caspase-3/7 activation decreased during cryopreservation (from 36.6 ± 9.1% to 1.5 ± 2.2%), and the other subpopulation where caspase-3/7 activation increased after cryopreservation (from 37.7 ± 13.0% to 64.3 ± 16.7%). In conclusion, after 3-4 h of incubation, caspase-3/7 activation increased in fresh alpaca sperm, whereas cryopreservation affects alpaca sperm samples in different ways.

Asunto(s)

Camélidos del Nuevo Mundo , Preservación de Semen , Masculino , Animales , Camélidos del Nuevo Mundo/fisiología , Caspasa 3 , Semen/fisiología , Espermatozoides/fisiología , Criopreservación/veterinaria , Caspasas/metabolismo , Preservación de Semen/veterinaria , Motilidad Espermática/fisiología

RESUMEN

Cancer is a relevant health problem worldwide. In 2020, leukemias represented the 13th most commonly reported cancer cases worldwide but the 10th most likely to cause deaths. There has been a progressive increase in the efficacy of treatments for leukemias; however, these still generate important side effects, so it is imperative to search for new alternatives. Defensins are a group of antimicrobial peptides with activity against cancer cells. However, the cytotoxic mechanism of these peptides has been described mainly for animal defensins. This study shows that defensin γ-thionin (Capsicum chinense) is cytotoxic to the K562 leukemia cells with an IC50 = 290 µg/mL (50.26 µM) but not for human peripheral blood mononuclear cells. Results showed that γ-thionin did not affect the membrane potential; however, the peptide modified the mitochondrial membrane potential (ΔΨm) and the intracellular calcium release. In addition, γ-thionin induced apoptosis in K562 cells, but the activation of caspases 8 and 9 was not detected. Moreover, the activation of calpains was detected at one hour of treatment, suggesting that γ-thionin activates the caspase-independent apoptosis. Furthermore, the γ-thionin induced epigenetic modifications on histone 3 in K562 cells, increased global acetylation (~2-fold), and specific acetylation marks at lysine 9 (H3K9Ac) (~1.5-fold). In addition, γ-thionin increased the lysine 9 methylation (H3K9me) and dimethylation marks (H3K9me2) (~2-fold), as well as the trimethylation mark (H3K9me3) (~2-fold). To our knowledge, this is the first report of a defensin that triggers caspase-independent apoptosis in cancer cells via calpains and regulating chromatin remodelation, a novel property for a plant defensin.

Asunto(s)

Antineoplásicos , Capsicum , Leucemia Mielógena Crónica BCR-ABL Positiva , Tioninas , Animales , Humanos , Tioninas/farmacología , Células K562 , Capsicum/química , Péptidos Antimicrobianos , Chile , Leucocitos Mononucleares/metabolismo , Lisina/farmacología , Apoptosis , Péptidos/farmacología , Antineoplásicos/farmacología , Caspasas/metabolismo , Defensinas/farmacología , Epigénesis Genética

RESUMEN

In this study, we aimed to evaluate two sets of sesquiterpene-aryl derivatives linked by an ester bond, their cytotoxic activities, and their capacity to activate caspases 3/7 and inhibit human topoisomerase I (TOP1). A total of 13 compounds were synthesized from the natural sesquiterpene (-)-drimenol and their cytotoxic activity was evaluated in vitro against three cancer cell lines: PC-3 (prostate cancer), HT-29 (colon cancer), MCF-7 (breast cancer), and an immortalized non-tumoral cell line (MCF-10). From the results, it was observed that 6a was the most promising compound due to its cytotoxic effect on three cancer cell lines and its selectivity, 6a was 100-fold more selective than 5-FU in MCF-7 and 20-fold in PC-3. It was observed that 6a also induced apoptosis by caspases 3/7 activity using a Capsase-Glo-3/7 assay kit and inhibited TOP1. A possible binding mode of 6a in a complex with TOP1-DNA was proposed by docking and molecular dynamics studies. In addition, 6a was predicted to have a good pharmacokinetic profile for oral administration. Therefore, through this study, it was demonstrated that the drimane scaffold should be considered in the search of new antitumoral agents.

Asunto(s)

Antineoplásicos , Sesquiterpenos , Humanos , Línea Celular Tumoral , ADN-Topoisomerasas de Tipo I/metabolismo , Ésteres/farmacología , Antineoplásicos/química , Sesquiterpenos/farmacología , Apoptosis , Caspasas/metabolismo , Ensayos de Selección de Medicamentos Antitumorales , Simulación del Acoplamiento Molecular , Proliferación Celular , Relación Estructura-Actividad , Estructura Molecular

RESUMEN

Down syndrome (DS) is characterized by the trisomy of chromosome 21 and by cognitive deficits that have been related to neuronal morphological alterations in humans, as well as in animal models. The gene encoding for amyloid precursor protein (APP) is present in autosome 21, and its overexpression in DS has been linked to neuronal dysfunction, cognitive deficit, and Alzheimer's disease-like dementia. In particular, the neuronal ability to extend processes and branching is affected. Current evidence suggests that APP could also regulate neurite growth through its role in the actin cytoskeleton, in part by influencing p21-activated kinase (PAK) activity. The latter effect is carried out by an increased abundance of the caspase cleavage-released carboxy-terminal C31 fragment. In this work, using a neuronal cell line named CTb, which derived from the cerebral cortex of a trisomy 16 mouse, an animal model of human DS, we observed an overexpression of APP, elevated caspase activity, augmented cleavage of the C-terminal fragment of APP, and increased PAK1 phosphorylation. Morphometric analyses showed that inhibition of PAK1 activity with FRAX486 increased the average length of the neurites, the number of crossings per Sholl ring, the formation of new processes, and stimulated the loss of processes. Considering our results, we propose that PAK hyperphosphorylation impairs neurite outgrowth and remodeling in the cellular model of DS, and therefore we suggest that PAK1 may be a potential pharmacological target.

Asunto(s)

Síndrome de Down , Ratones , Humanos , Animales , Síndrome de Down/tratamiento farmacológico , Síndrome de Down/genética , Trisomía , Neuronas/metabolismo , Neuritas/metabolismo , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Proyección Neuronal , Caspasas/metabolismo

RESUMEN

Human immunodeficiency virus (HIV) neuroinvasion occurs early after infection through the trafficking of virus-infected immune cells into the central nervous system (CNS) and viral dissemination into the brain. There, it can infect resident brain cells including astrocytes, the most abundant cell type that is crucial to brain homeostasis. In this report, we examined the HIV-related mechanism able to induce bystander cell death in astrocytes mediated by cell-to-cell contact with productively infected (PI) ones. We first demonstrate that HIV-induced bystander cell death involves mitochondrial dysfunction that promotes exacerbated reactive oxygen species production. Such a phenomenon is a contagious cell death that requires contact with HIV-PI astrocytes that trigger caspase-dependent (apoptosis and pyroptosis) and caspase-independent cell death pathways. The HIV accessory proteins Nef, Vpu, and Vpr counteract astrocyte death among PI cells but, in contrast, participate to promote contagious bystander cell death by inducing mitochondrial reactive oxygen species production. Our findings indicate that astrocytes PI by HIV became capable to counteract infection-derived death signals, surviving, and spreading the bystander cell death into neighboring uninfected cells by a cell-to-cell contact-dependent mechanism. Considering that astrocytes have been proposed as a long-term HIV reservoir in the CNS, ascertaining the mechanism of survival and contagious bystander death will afford clear targets in the current goal to achieve a functional cure.

Asunto(s)

Infecciones por VIH , VIH-1 , Humanos , Astrocitos/metabolismo , VIH-1/fisiología , Especies Reactivas de Oxígeno/metabolismo , Muerte Celular , Caspasas/metabolismo

RESUMEN

Different hybrids based on curcumin and resveratrol were previously synthesized and characterized by spectroscopic techniques. The most active molecules (3a, 3e, 3i, and 3k) were evaluated in vitro as an approach to determine the possible mechanism of action of the hybrids. The results indicated that the evaluated curcumin/resveratrol hybrids induce mitochondrial instability in SW620 and SW480 cells. Moreover, these molecules caused a loss in membrane integrity, suggesting an apoptotic process mediated by caspases after the treatment with compounds 3i (SW480) and 3k (SW620). In addition, the results suggest that the mechanism of action of the hybrids could be independent of the p53 status. Furthermore, hybrids 3e and 3i caused G0/G1 phase arrest, which highlights the potential of these molecules not only as cytotoxic but also as cytostatic compounds. Hybrids 3e and 3i caused a negative modulation of the matrix metalloproteinase 7 (MMP7) on SW480 cells. These curcumin resveratrol hybrids could be potential candidates for further investigations in the search for potential chemopreventive agents, even in those cases with resistance to conventional chemotherapy because of the lack of p53 expression or function. Molecular docking simulations showed that compounds 3e, 3i, and 3k bind efficiently to proapoptotic human caspases 3/7 proteins, as well as human MMP-7 and p53, which, in turn, could explain at the molecular level the in vitro cytotoxic effect of these compounds in SW480 and SW620 colon cancer cell lines.

Asunto(s)

Antineoplásicos , Neoplasias del Colon , Curcumina , Antineoplásicos/química , Apoptosis , Proteínas Reguladoras de la Apoptosis/metabolismo , Caspasas/metabolismo , Quimioprevención , Neoplasias del Colon/tratamiento farmacológico , Curcumina/farmacología , Curcumina/uso terapéutico , Humanos , Simulación del Acoplamiento Molecular , Resveratrol/farmacología , Resveratrol/uso terapéutico , Proteína p53 Supresora de Tumor/metabolismo

RESUMEN

Malaria is an enormous burden on global health that caused 409,000 deaths in 2019. Severe malaria can manifest in the lungs, an illness known as acute respiratory distress syndrome (ARDS). Not much is known about the development of malaria-associated ARDS (MA-ARDS), especially regarding cell death in the lungs. We had previously established a murine model that mimics various human ARDS aspects, such as pulmonary edema, hemorrhages, pleural effusion, and hypoxemia, using DBA/2 mice infected with Plasmodium berghei ANKA. Here, we explored the mechanisms and the involvement of apoptosis in this syndrome. We found that apoptosis contributes to the pathogenesis of MA-ARDS, primarily as facilitators of the alveolar-capillary barrier breakdown. The protection of pulmonary endothelium by inhibiting caspase activation could be a promising therapeutic strategy to prevent the pathogenicity of MA-ARDS. Therefore, intervention in the programmed death cell mechanism could help patients not to develop severe malaria.

Asunto(s)

Malaria , Síndrome de Dificultad Respiratoria , Animales , Caspasas/metabolismo , Modelos Animales de Enfermedad , Humanos , Pulmón/metabolismo , Malaria/complicaciones , Malaria/metabolismo , Ratones , Ratones Endogámicos DBA

RESUMEN

BACKGROUND: This study investigated the modulatory capacity of two Solanum green leafy vegetables; S. macrocarpon L. (African eggplant AE) and S. nigrum L. (Black nightshade BN) on dysregulation of some antioxidant, pro-apoptotic, pro-inflammatory-like, acetylcholinesterase gene expression and redox status in the Drosophila melanogaster model of aluminum-induced neurotoxicity. METHODS: Flies were exposed to AlCl3 (6.7 mM) alone or in combination with the leaves (0.1 and 1.0%) from both samples in their diet for seven days. Thereafter, the fly heads were rapidly separated, homogenized, and used to assay for reactive oxygen species (ROS), total thiol content, catalase, glutathione-S-transferase (GST), acetylcholinesterase (AChE) activities, and the expression of antioxidant-mediators (Hsp70, catalase, cnc/Nrf2, Jafrac1 and FOXO), acetylcholinesterase (Ace1), pro-apoptotic caspase-like (Dronc) and its regulator (reaper), as well as inflammation-related (NF-kB/Relish) genes. RESULTS: Results showed that AlCl3-exposed flies had significantly reduced survival rate which were ameliorated by AlCl3 also elevated ROS, GST and reduced AChE activities in fly heads while dietary inclusions of AE and BN ameliorated survial rate and oxidative stress in AlCl3-exposed flies. In addition, Hsp70, Jafrac1, reaper and NF-kҝB/Relish were significantly upregulated in AlCl3-exposed fly heads, while cnc/Nrf2 and FOXO were significantly downregulated, but catalase, Dronc and Ace were, not significantly modulated. Nevertheless, these impairments in gene expression levels were ameliorated by dietary inclusions of AE and BN during AlCl3 exposure. CONCLUSION: These findings showed that dietary inclusions of AE and BN leaves offer protection against Al-induced neurotoxicity in D. melanogaster and thus, could serve as functional foods with neuroprotective properties.

Asunto(s)

Síndromes de Neurotoxicidad , Solanum nigrum , Solanum , Acetilcolinesterasa/metabolismo , Aluminio/metabolismo , Animales , Antioxidantes/metabolismo , Caspasas/genética , Caspasas/metabolismo , Catalasa/genética , Catalasa/metabolismo , Dieta , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Glutatión/metabolismo , Glutatión Transferasa/metabolismo , Inflamación/inducido químicamente , Inflamación/prevención & control , Factor 2 Relacionado con NF-E2/metabolismo , FN-kappa B/metabolismo , Síndromes de Neurotoxicidad/etiología , Síndromes de Neurotoxicidad/metabolismo , Síndromes de Neurotoxicidad/prevención & control , Oxidación-Reducción , Estrés Oxidativo , Especies Reactivas de Oxígeno/metabolismo , Solanum/metabolismo , Solanum nigrum/metabolismo , Compuestos de Sulfhidrilo/metabolismo , Verduras

RESUMEN

Varicocele has been hypothesized to lead to seminal inflammation, which in turn interferes with sperm function. Thus, the aim of this study was to investigate the role of inflammatory cytokines in the pathogenesis of decreased semen quality observed in adult men with varicocele, and to determine if varicocelectomy corrects these potential alterations. A prospective study was carried out including fifteen control men without varicocele and with normal semen quality and 15 men with varicocele with surgical indication. Men with varicocele grades II or III underwent microsurgical subinguinal varicocelectomy. Controls collected one semen sample and men with varicocele collected one before and one 6 months after the surgery. Semen analysis, sperm function, and seminal lipid peroxidation levels were assessed. Seminal plasma inflammasome activity was evaluated by ELISA assays for IL-1ß, IL-18 and caspase-1 and by Western blotting for ASC (apoptosis-associated speck-like protein). Groups were compared by an unpaired Student's T test. Varicocelectomy samples were compared using a paired Student's T test (α = 5%). Men with varicocele had decreased semen quality, and increased seminal IL-1ß levels, when compared to control men. Varicocelectomy decreased levels of caspase-1, IL-18, and IL1ß. Thus, varicocelectomy improves sperm morphology and decreases seminal plasma inflammatory activity, after a six-month post-operative period.

Asunto(s)

Infertilidad Masculina , Varicocele , Adulto , Caspasas/metabolismo , Humanos , Infertilidad Masculina/metabolismo , Inflamasomas/metabolismo , Interleucina-18/metabolismo , Masculino , Estudios Prospectivos , Semen/metabolismo , Análisis de Semen , Varicocele/cirugía