RESUMO
Heart failure, a growing concern in the United States, significantly impacts both morbidity and mortality. Classified by ejection fraction, heart failure with preserved ejection fraction (HFpEF) now accounts for half of all cases and is steadily rising. Unlike its counterpart, heart failure with reduced ejection fraction (HFrEF), HFpEF lacks clear management guidelines. Recognizing this critical gap, we aim to review existing recommendations and formulate effective management strategies for HFpEF.
RESUMO
Leishmania mexicana is one of the causative agents of cutaneous leishmaniasis in humans. There is an urgent need to identify new drug targets to combat the disease. Cysteine peptidases play crucial role in pathogenicity and virulence in Leishmania spp. and are promising targets for developing new anti-leishmanial drugs. Genetic drug target validation has been performed on a number of cysteine peptidases, but others have yet to be characterized. We targeted 16 L. mexicana cysteine peptidases for gene deletion and tagging using CRISPR-Cas9 in order to identify essential genes and ascertain their cellular localization. Our analysis indicates that two clan CA, family C2 calpains (LmCAL27.1, LmCAL31.6) and clan CD, family C11 PNT1 are essential for survival in the promastigote stage. The other peptidases analysed, namely calpains LmCAL4.1, LmCAL25.1, and members of clan CA C51, C78, C85 and clan CP C97 were found to be non-essential. We generated a gene deletion mutant (Δpnt1) which was severely compromised in its cell growth and a conditional gene deletion mutant of PNT1 (Δpnt1: PNT1flox/Δ pnt1:HYG [SSU DiCRE]). PNT1 localizes to distinct foci on the flagellum and on the surface of the parasite. The conditional gene deletion of PNT1 induced blebs and pits on the cell surface and eventual cell death. Over-expression of PNT1, but not an active site mutant PNT1C134A, was lethal, suggesting that active PNT1 peptidase is required for parasite survival. Overall, our data suggests that PNT1 is an essential gene and one of a number of cysteine peptidases that are potential drug targets in Leishmania.
Assuntos
Cisteína Endopeptidases/genética , Cisteína Endopeptidases/fisiologia , Leishmania mexicana/enzimologia , Leishmaniose Cutânea/parasitologia , Proteínas de Protozoários/genética , Proteínas de Protozoários/fisiologia , Deleção de Genes , Genes Essenciais , Humanos , Leishmania mexicana/genética , Leishmania mexicana/patogenicidade , Virulência/genéticaRESUMO
Trypanosomatid parasites cause diseases in humans and livestock. It was reported that partial inhibition of the vacuolar ATPase (V-ATPase) affects the dependence of Trypanosoma brucei on its mitochondrial genome (kinetoplast DNA [kDNA]), a target of the antitrypanosomatid drug isometamidium. Here, we report that V-ATPase inhibition with bafilomycin A1 (BafA) provides partial resistance to genetic knockdown of mitochondrial gene expression. BafA does not promote long-term survival after kDNA loss, but in its presence, isometamidium causes less damage to kDNA.
Assuntos
Genes Mitocondriais/efeitos dos fármacos , Genoma Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Tripanossomicidas/farmacologia , Trypanosoma brucei brucei/efeitos dos fármacos , ATPases Vacuolares Próton-Translocadoras/antagonistas & inibidores , Animais , DNA de Cinetoplasto/efeitos dos fármacos , DNA de Cinetoplasto/genética , Expressão Gênica/efeitos dos fármacos , Expressão Gênica/genética , Técnicas de Silenciamento de Genes/métodos , Genes Mitocondriais/genética , Genoma Mitocondrial/genética , Humanos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Fenantridinas/farmacologia , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Trypanosoma brucei brucei/genética , Trypanosoma brucei brucei/metabolismoRESUMO
The genome of Entamoeba histolytica encodes several calcium binding proteins and those characterized thus far have been shown to participate predominantly in phagocytosis and endocytosis. Our study showed that EhCaBP6 has two EF-hand domains EFI and EFIII; it can bind Ca(2+) in vitro and undergoes conformational transition on binding Ca(2+) suggesting that it can serve as a calcium signal sensor. EhCaBP6 is localized in the nucleus, cytoplasm and plasma membrane and is sensitive to heat stress. Unlike other Ca(2+) binding proteins that have been studied in E. histolytica, EhCaBP6 is found at microtubule ends and at the intercellular bridge with the microtubules during cytokinesis. Furthermore, increased expression of EhCaBP6 was correlated with a significant increase in the number of microtubular structures suggesting that this protein may regulate chromosome segregation and cytokinesis in E. histolytica.
Assuntos
Proteínas de Bactérias/metabolismo , Sinalização do Cálcio/genética , Proteínas de Ligação ao Cálcio/metabolismo , Entamoeba histolytica/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/imunologia , Cálcio/metabolismo , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/imunologia , Segregação de Cromossomos/genética , Citocinese/genética , Endocitose/genética , Microtúbulos/metabolismo , Mitose/genética , Fagocitose/genética , Ligação Proteica/genética , Estrutura Terciária de Proteína , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismoRESUMO
We have recently identified a novel galacto-glycerolipid (GGL) from the plant Oxalis corniculata that killed the human pathogen Entamoeba histolytica. In this study, we show that the anti-amoebic activity of GGL was due to the polyunsaturated fatty acid α-linolenic acid (C18:3 ) side chain. Treatment of α-linolenic acid to E. histolytica trophozoites disrupted the cytoskeletal network and led to polarization of F-actin at one end of the cells with prominent filopodial extensions. In addition, clustering of surface receptors and signaling molecules was also observed adjacent to the polarized actin similar to concanavalin-A-(Con-A) induced capping. But, in contrast to Con-A-induced capping, α-linolenic acid induced caps were not shed and showed accumulation of long and numerous filopodia at the cap site. We found that α-linolenic acid disrupts the actin cytoskeletal network, which led to the detachment of plasma membrane from the underlying cytoskeleton. A similar effect was observed with other dietary fatty acids such as linoleic acid (C18:2 ), arachidonic acid (C20:4 ), eicosapentaenoic acid (C20:5 ), and docosahexaenoic acid (C22:6 ). Our findings showed that dietary polyunsaturated fatty acids are powerful anti-amoebic agents that lead to disruption of the actin cytoskeleton.
