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Malaria parasite invasion to host erythrocytes is mediated by multiple interactions between merozoite ligands and erythrocyte receptors that contribute toward the development of disease pathology. Here, we report a novel antigen Plasmodium prohibitin "PfPHB2" and identify its cognate partner "Hsp70A1A" in host erythrocyte that plays a crucial role in mediating host-parasite interaction during merozoite invasion. Using small interfering RNA (siRNA)- and glucosamine-6-phosphate riboswitch (glmS) ribozyme-mediated approach, we show that loss of Hsp70A1A in red blood cells (RBCs) or PfPHB2 in infected red blood cells (iRBCs), respectively, inhibit PfPHB2-Hsp70A1A interaction leading to invasion inhibition. Antibodies targeting PfPHB2 and monoclonal antibody therapeutics against Hsp70A1A efficiently block parasite invasion. Recombinant PfPHB2 binds to RBCs which is inhibited by anti-PfPHB2 antibody and monoclonal antibody against Hsp70A1A. The validation of PfPHB2 to serve as antigen is further supported by detection of anti-PfPHB2 antibody in patient sera. Overall, this study proposes PfPHB2 as vaccine candidate and highlights the use of monoclonal antibody therapeutics for future malaria treatment.
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Ex vivo cellular system that accurately replicates sickle cell disease and ß-thalassemia characteristics is a highly sought-after goal in the field of erythroid biology. In this study, we present the generation of erythroid progenitor lines with sickle cell disease and ß-thalassemia mutation using CRISPR/Cas9. The disease cellular models exhibit similar differentiation profiles, globin expression and proteome dynamics as patient-derived hematopoietic stem/progenitor cells. Additionally, these cellular models recapitulate pathological conditions associated with both the diseases. Hydroxyurea and pomalidomide treatment enhanced fetal hemoglobin levels. Notably, we introduce a therapeutic strategy for the above diseases by recapitulating the HPFH3 genotype, which reactivates fetal hemoglobin levels and rescues the disease phenotypes, thus making these lines a valuable platform for studying and developing new therapeutic strategies. Altogether, we demonstrate our disease cellular systems are physiologically relevant and could prove to be indispensable tools for disease modeling, drug screenings and cell and gene therapy-based applications.
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Anemia Falciforme , Talassemia beta , Humanos , Talassemia beta/genética , Talassemia beta/terapia , Hemoglobina Fetal/genética , Hemoglobina Fetal/metabolismo , Anemia Falciforme/tratamento farmacológico , Anemia Falciforme/genética , Células-Tronco Hematopoéticas/metabolismo , Genótipo , Sistemas CRISPR-CasRESUMO
Modern agriculture is primarily focused on the massive production of cereals and other food-based crops in a sustainable manner in order to fulfill the food demands of an ever-increasing global population. However, intensive agricultural practices, rampant use of agrochemicals, and other environmental factors result in soil fertility degradation, environmental pollution, disruption of soil biodiversity, pest resistance, and a decline in crop yields. Thus, experts are shifting their focus to other eco-friendly and safer methods of fertilization in order to ensure agricultural sustainability. Indeed, the importance of plant growth-promoting microorganisms, also determined as "plant probiotics (PPs)," has gained widespread recognition, and their usage as biofertilizers is being actively promoted as a means of mitigating the harmful effects of agrochemicals. As bio-elicitors, PPs promote plant growth and colonize soil or plant tissues when administered in soil, seeds, or plant surface and are used as an alternative means to avoid heavy use of agrochemicals. In the past few years, the use of nanotechnology has also brought a revolution in agriculture due to the application of various nanomaterials (NMs) or nano-based fertilizers to increase crop productivity. Given the beneficial properties of PPs and NMs, these two can be used in tandem to maximize benefits. However, the use of combinations of NMs and PPs, or their synergistic use, is in its infancy but has exhibited better crop-modulating effects in terms of improvement in crop productivity, mitigation of environmental stress (drought, salinity, etc.), restoration of soil fertility, and strengthening of the bioeconomy. In addition, a proper assessment of nanomaterials is necessary before their application, and a safer dose of NMs should be applicable without showing any toxic impact on the environment and soil microbial communities. The combo of NMs and PPs can also be encapsulated within a suitable carrier, and this method aids in the controlled and targeted delivery of entrapped components and also increases the shelf life of PPs. However, this review highlights the functional annotation of the combined impact of NMs and PPs on sustainable agricultural production in an eco-friendly manner.
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Cold shock proteins are characterized by the presence of one or more cold shock domains that bestow them with nucleic acid binding ability. Although cold shock proteins are well characterized in bacteria, plants and humans, there is no information on their existence and role in malaria parasite. Here, we have identified and delineated the function of a cold shock protein of Plasmodium falciparum (Pf) 'PfCoSP'. We demonstrate that PfCoSP exhibits nucleic acid binding properties and regulates gene expression. PfCoSP promotes microtubule assembly by interacting with Pf α/ß tubulin. We identified a human cold shock protein LIN28A inhibitor 'LI71' as a binding partner of PfCoSP which inhibited PfCoSP-DNA and α/ß tubulin interactions and, also inhibited the development of asexual blood stages and gametocyte stage of malaria parasite. Because PfCoSP is essential for parasite survival, characterization of its interacting partners may form the basis for development of future anti-malarials.
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The evolution of resistance to practically all antimalarial drugs poses a challenge to the current malaria elimination and eradication efforts. Given that the epigenome of Plasmodium falciparum governs several crucial parasite functions, pharmaceutical interventions with transmission-blocking potential that target epigenetic molecular markers and regulatory mechanisms are likely to encounter drug resistance. In the malaria parasite, histone deacetylases (HDACs) are essential epigenetic modulators that regulate cellular transcriptional rearrangements, notably the molecular mechanisms underlying parasite proliferation and differentiation. We establish "lipid sequestration" as a mechanism by which sphingolipids, specifically Sphingosine-1-Phosphate (S1P) (a metabolic product of Sphingosine Kinase 1 [SphK-1]), regulate epigenetic reprogramming in the parasite by interacting with, and modulating, the histone-deacetylation activity of PfHDAC-1, thereby regulating Plasmodium pathogenesis. Furthermore, we demonstrate that altering host S1P levels with PF-543, a potent and selective Sphk-1 inhibitor, dysregulates PfHDAC-1 activity, resulting in a significant increase in the global histone acetylation signals and, consequently, transcriptional modulation of genes associated with gametocytogenesis, virulence, and proliferation. Our findings point to a hitherto unrecognized functional role for host S1P-mediated sphingolipid signaling in modulating PfHDAC-1's enzymatic activity and, as a result, the parasite's dynamic genome-wide transcriptional patterns. The epigenetic regulation of parasite proliferation and sexual differentiation offers a novel approach for developing host-targeted therapeutics to combat malaria resistance to conventional regimens. IMPORTANCE Sphingolipid is an 18-carbon amino-alcohol-containing lipid with a sphingosine backbone, which when phosphorylated by sphingosine kinase 1 (SphK-1), generates sphingosine-1-phosphate (S1P), an essential lipid signaling molecule. Dysregulation of S1P function has been observed in a variety of pathologies, including severe malaria. The malaria parasite Plasmodium acquires a host S1P pool for its growth and survival. Here, we describe the molecular attuning of histone deacetylase-1 (PfHDAC-1), a crucial epigenetic modulator that contributes to the establishment of epigenetic chromatin states and parasite survival, in response to S1P binding. Our findings highlight the host lipid-mediated epigenetic regulation of malaria parasite key genes.
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The emergence of resistance to conventional antimalarial treatments remains a major cause for concern. New drugs that target the distinct development stages of Plasmodium parasites are required to address this risk. Herein, water-soluble aggregation-induced emission active cyclometalated iridium(III) polypyridyl complexes (Ir1-Ir12) are developed for the elimination of malaria parasites. Remarkably, these complexes show potent antimalarial activity in low nanomolar range against 3D7 (chloroquine and artemisinin sensitive strain), RKL9 (chloroquine resistant strain), and R539T (artemisinin resistant strains) strains of Plasmodium falciparum with faster killing rate of malaria parasites. Concomitantly, these complexes exhibit efficient in vivo antimalarial activity against both the asexual and gametocyte stages of Plasmodium berghei malaria parasite, suggesting promising transmission-blocking potential. The complexes tend to localize into mitochondria of P. falciparum determined by image and cell-based assay. The mechanistic studies reveal that these complexes exert their antimalarial activity by increasing reactive oxygen species levels and disrupting its mitochondrial membrane potential. Furthermore, the mitochondrial-dependent antimalarial activity of these complexes is confirmed in yeast model. Thus, this study for the first time highlights the potential role of targeting P. falciparum mitochondria by iridium complexes in discovering and developing the next-generation antimalarial agents for treating multidrug resistant malaria parasites.
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Irídio , Malária Falciparum , Mitocôndrias , Plasmodium falciparum , Humanos , Antimaláricos/farmacologia , Artemisininas/farmacologia , Cloroquina/farmacologia , Resistência a Múltiplos Medicamentos , Irídio/farmacologia , Malária Falciparum/tratamento farmacológico , Malária Falciparum/parasitologia , Mitocôndrias/efeitos dos fármacos , Plasmodium falciparum/efeitos dos fármacosRESUMO
The emergence of Plasmodium falciparum resistance raises an urgent need to find new antimalarial drugs. Here, we report the rational repurposing of the anti-hepatitis C virus drug, alisporivir, a nonimmunosuppressive analog of cyclosporin A, against artemisinin-resistant strains of P. falciparum. In silico docking studies and molecular dynamic simulation predicted strong interaction of alisporivir with PfCyclophilin 19B, confirmed through biophysical assays with a Kd value of 354.3 nM. Alisporivir showed potent antimalarial activity against chloroquine-resistant (PfRKL-9 with resistance index [Ri] 2.14 ± 0.23) and artemisinin-resistant (PfKelch13R539T with Ri 1.15 ± 0.04) parasites. The Ri is defined as the ratio between the IC50 values of the resistant line to that of the sensitive line. To further investigate the mechanism involved, we analyzed the expression level of PfCyclophilin 19B in artemisinin-resistant P. falciparum (PfKelch13R539T). Semiquantitative real-time transcript, Western blot, and immunofluorescence analyses confirmed the overexpression of PfCyclophilin 19B in PfKelch13R539T. A 50% inhibitory concentration in the nanomolar range, together with the targeting of PfCyclophilin 19B, suggests that alisporivir can be used in combination with artemisinin. Since artemisinin resistance slows the clearance of ring-stage parasites, we performed a ring survival assay on artemisinin-resistant strain PfKelch13R539T and found significant decrease in parasite survival with alisporivir. Alisporivir was found to act synergistically with dihydroartemisinin and increase its efficacy. Furthermore, alisporivir exhibited antimalarial activity in vivo. Altogether, with the rational target-based Repurposing of alisporivir against malaria, our results support the hypothesis that targeting resistance mechanisms is a viable approach toward dealing with drug-resistant parasite.
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Antimaláricos , Artemisininas , Malária Falciparum , Malária , Humanos , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Ciclosporina/farmacologia , Ciclosporina/uso terapêutico , Reposicionamento de Medicamentos , Resistência a Medicamentos , Artemisininas/farmacologia , Artemisininas/uso terapêutico , Malária/tratamento farmacológico , Malária Falciparum/tratamento farmacológico , Plasmodium falciparumRESUMO
Post-translational modifications (PTMs) including phosphorylation and palmitoylation have emerged as crucial biomolecular events that govern many cellular processes including functioning of motility- and invasion-associated proteins during Plasmodium falciparum invasion. However, no study has ever focused on understanding the possibility of a crosstalk between these two molecular events and its direct impact on preinvasion- and invasion-associated protein-protein interaction (PPI) network-based molecular machinery. Here, we used an integrated in silico analysis to enrich two different catalogues of proteins: (i) the first group defines the cumulative pool of phosphorylated and palmitoylated proteins, and (ii) the second group represents a common set of proteins predicted to have both phosphorylation and palmitoylation. Subsequent PPI analysis identified an important protein cluster comprising myosin A tail interacting protein (MTIP) as one of the hub proteins of the glideosome motor complex in P. falciparum, predicted to have dual modification with the possibility of a crosstalk between the same. Our findings suggested that blocking palmitoylation led to reduced phosphorylation and blocking phosphorylation led to abrogated palmitoylation of MTIP. As a result of the crosstalk between these biomolecular events, MTIP's interaction with myosin A was found to be abrogated. Next, the crosstalk between phosphorylation and palmitoylation was confirmed at a global proteome level by click chemistry and the phenotypic effect of this crosstalk was observed via synergistic inhibition in P. falciparum invasion using checkerboard assay and isobologram method. Overall, our findings revealed, for the first time, an interdependence between two PTM types, their possible crosstalk, and its direct impact on MTIP-mediated invasion via glideosome assembly protein myosin A in P. falciparum. These insights can be exploited for futuristic drug discovery platforms targeting parasite molecular machinery for developing novel antimalarial therapeutics.
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Antimaláricos , Proteínas do Citoesqueleto/metabolismo , Malária Falciparum , Proteínas de Membrana/metabolismo , Miosina não Muscular Tipo IIA , Humanos , Lipoilação , Malária Falciparum/parasitologia , Miosina não Muscular Tipo IIA/química , Miosina não Muscular Tipo IIA/metabolismo , Fosforilação , Plasmodium falciparum , Proteoma/metabolismo , Proteínas de Protozoários/metabolismoRESUMO
The increased resistance of human malaria parasite Plasmodium falciparum (Pf) to currently used drugs necessities the development of novel anti-malarials. Here, we examine the potential of erythritol, a sugar substitute for therapeutic intervention. Erythritol is a permeant of Plasmodium falciparum aquaglyceroporin (PfAQP) which is a multifunctional channel responsible for maintaining hydro-homeostasis. We show that erythritol effectively inhibited growth and progression of asexual blood stage malaria parasite, and effect invasion and egress processes. It also inhibited the liver stage (sporozoites) and transmission stage parasite (gametocytes) development. Interestingly, erythritol inhibited in vivo growth of malaria parasite in mouse experimental model. It was more effective in inhibiting parasite growth both in vivo and in vitro when tested together with a known anti-malarial 'artesunate'. Additionally, erythritol showed cytokine-modulating effect which suggests its direct effect on the host immune system. Ammonia detection assay demonstrated that erythritol uptake effects the amount of ammonia release across the parasite. Our functional complementation assays suggest that PfAQP expression in yeast mutant restores its growth in hyperosmotic conditions but showed reduced growth in the presence of erythritol. Osmotic lysis assay suggests that erythritol creates osmotic stress for killing the parasite. Overall, our data bestow erythritol as a promising lead compound with an attractive antimalarial profile and could possibly be combined with known drugs without losing its efficacy. We propose the use of erythritol based sweet candies for protection against malaria specially in children living in the endemic area.
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Antimaláricos , Aquagliceroporinas , Criança , Camundongos , Humanos , Animais , Antimaláricos/farmacologia , Plasmodium falciparum , Aquagliceroporinas/farmacologia , Eritritol/farmacologia , Edulcorantes , Amônia/farmacologia , Citocinas/farmacologiaRESUMO
LAMP diagnosis of malaria is simple and cost-effective with acceptable sensitivity and specificity as compared to standard diagnostic modules such as microscopy, RDTs and nested PCR, and thus its deployment for onsite screening of malaria in resource-limited regions is under consideration. However, the requirement of an electricity-operated dry bath and bulky read-out unit is still a major concern. In an effort to simplify this limitation, we have developed a portable LAMP device and fluorescence readout unit which can be used in the rapid point-of-care diagnosis of malaria. We have developed a point-of-care diagnostic LAMP device that is easy to operate by a mobile application, and the results can be quantified with a fluorescent readout unit. The diagnostic performance of the device was evaluated in 90 P. falciparum-infected clinical isolates stored at 4°C for 6-7 years and 10 freshly collected isolates from healthy volunteers. The LOD and quantitative ability of LAMP in estimating parasitemia levels were revealed with laboratory-grown P. falciparum strain (3D7). The LAMP assay performed in our device was exclusive for P. falciparum detection with sensitivity and specificity determined to be 98.89% and 100%, respectively, in clinical isolates. The LOD was documented to be 1 parasite/µl at the cut-off ADC value of 20. Parasite density estimated from ADC values showed concordance with microscopically determined parasite density of the cultured P. falciparum 3D7 strain. The LAMP assay performed in our device provides a possible portable platform for its deployment in the point-of-care diagnosis of malaria. Further validation of the quantitative ability of the assay with freshly collected or properly stored clinical samples of known parasitemia is necessary for field applicability.
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Malária Falciparum , Malária , Humanos , Malária/parasitologia , Malária Falciparum/diagnóstico , Malária Falciparum/parasitologia , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificação de Ácido Nucleico , Parasitemia/diagnóstico , Plasmodium falciparum/genética , Sistemas Automatizados de Assistência Junto ao Leito , Sensibilidade e EspecificidadeRESUMO
Phosphorylation and other post-translational modifications of red blood cell (RBC) proteins govern membrane function and have a role in the invasion of RBCs by the malaria parasite, Plasmodium falciparum. Furthermore, a percentage of RBC proteins are palmitoylated, although the functional consequences are unknown. We establish dynamic palmitoylation of 118 RBC membrane proteins using click chemistry and acyl biotin exchange (ABE)-coupled LC-MS/MS and characterize their involvement in controlling membrane organization and parasite invasion. RBCs were treated with a generic palmitoylation inhibitor, 2-bromopalmitate (2-BMP), and then analyzed using ABE-coupled LC-MS/MS. Only 42 of the 118 palmitoylated proteins detected were palmitoylated in the 2-BMP-treated sample, indicating that palmitoylation is dynamically regulated. Interestingly, membrane receptors such as semaphorin 7A, CR1, and ABCB6, which are known to be involved in merozoite interaction with RBCs and parasite invasion, were found to be dynamically palmitoylated, including the blood group antigen, Kell, whose antigenic abundance was significantly reduced following 2-BMP treatment. To investigate the involvement of Kell in merozoite invasion of RBCs, a specific antibody to its extracellular domain was used. The antibody targeting Kell inhibited merozoite invasion of RBCs by 50%, implying a role of Kell, a dynamically palmitoylated potent host-derived receptor, in parasite invasion. Furthermore, a significant reduction in merozoite contact with the RBC membrane and a consequent decrease in parasite invasion following 2-BMP treatment demonstrated that palmitoylation does indeed regulate RBC susceptibility to parasite invasion. Taken together, our findings revealed the dynamic palmitoylome of RBC membrane proteins and its role in P. falciparum invasion.
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Antígenos de Grupos Sanguíneos , Malária Falciparum , Parasitos , Semaforinas , Animais , Biotina/metabolismo , Antígenos de Grupos Sanguíneos/metabolismo , Cromatografia Líquida , Lipoilação , Proteínas de Membrana/metabolismo , Merozoítos/metabolismo , Parasitos/metabolismo , Plasmodium falciparum/metabolismo , Semaforinas/metabolismo , Espectrometria de Massas em TandemRESUMO
BACKGROUND AND AIM: Ischemic Stroke has been recognized as the principal cause of disability and the third leading cause of mortality worldwide. The aim of this study was to determine the frequency and pattern of dyslipidemia in patients presenting with ischemic stroke at a tertiary care hospital in Karachi, Pakistan and to evaluate the effect of demographic and clinical factors on the frequency and pattern of dyslipidemia in ischemic stroke subjects. Methods: A cross-sectional study carried on a sample size of 235 patients presenting to the out-patient clinic with paralysis, difficulty in speech, and/or loss of consciousness lasting for one hour or more. Blood samples were analyzed for total cholesterol (TC), triglycerides (TG), low-density lipoproteins (LDL), very low-density lipoproteins (VLDL) and high-density lipoproteins (HDL) by the enzymatic colorimetric methodology. These values were recorded on the pre-defined proforma by the investigators. All analysis was performed using SPSS version 23.0. Results: The average age of the patients was 50.84±11.51 years and 62.1% of them were males. The frequency of dyslipidemia was observed in more than half (n=134/235, 57.02%) of ischemic stroke patients. Regarding the dyslipidemia pattern, TC, VLDL-C and TG levels were deranged in more than 50% of the cases. The most commonly deranged values were of TC and VLDL-C, followed by TG levels. It was observed that patients with a previous history of DM (73.9%, p=0.002) and HTN (81.3%, p=0.001) had significantly higher rates of deranged lipid profiles. Lipid values were found to be more deranged in patients aged 41-50 years (p=0.002) however, no statistically significant differences were observed with respect to BMI (p=0.192) and symptoms duration (p=0.334). Conclusions: Dyslipidemia is an important risk factor for ischemic stroke, and elevated LDL-C is usually the lipid fraction implicated in the pathologic mechanism of stroke.
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Dislipidemias , AVC Isquêmico , Adulto , Estudos Transversais , Dislipidemias/epidemiologia , Feminino , Humanos , Lipídeos , Lipoproteínas LDL , Masculino , Pessoa de Meia-Idade , Estudos RetrospectivosRESUMO
Tannic acid (TA) is a natural compound present abundantly in fruit such as grapes and green tea. In this study, we have evaluated the therapeutic efficacy of TA against Lipopolysaccharide (LPS)-induced oxidative stress-mediated memory impairment, neuroinflammation, insulin signaling impairment, and Amyloid Beta (Aß) deposition in adult male mice. The LPS was administered once per week and TA twice a week to adult male mice for three months consecutively. Behavioral studies were performed using different behavioral models such as balance beam, novel object recognition (NOR), Morris water maze (MWM), and Y-maze tests. The protein expression of different mediators such as TNF-α, p-JNK, pIRS636, BACE1, APP, and Aß was evaluated through western blot and immunofluorescence staining techniques. Biochemical assays were carried out to assess the antioxidant activities of TA. The computational study was conducted to predict the binding mode of TA with target sites of TNF-α. Behavioral studies showed that the TA-treated mice exhibited gradual memory improvement. TA significantly inhibited BACE1 activity and reduced production and accumulation of Aß in the hippocampus of mice brains. Moreover, the TA significantly inhibited LPS-induced ROS production and enhanced the glutathione levels. Furthermore, we have shown via the computational method for the first time that TA inhibits LPS-triggered TNF-á½° and its downstream signaling to reduce AD pathology including memory impairment, neuroinflammation, insulin signaling impairment, and Aß deposition in adult mice. Taken together our current study demonstrates that TA is a potential candidate for the abrogation of LPS-induced neurotoxicity and AD pathology in rodent's models.
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Doença de Alzheimer , Disfunção Cognitiva , Insulinas , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Animais , Ácido Aspártico Endopeptidases/efeitos adversos , Ácido Aspártico Endopeptidases/metabolismo , Disfunção Cognitiva/induzido quimicamente , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/metabolismo , Modelos Animais de Doenças , Insulinas/efeitos adversos , Lipopolissacarídeos/farmacologia , Masculino , Aprendizagem em Labirinto , Transtornos da Memória/induzido quimicamente , Transtornos da Memória/tratamento farmacológico , Transtornos da Memória/metabolismo , Camundongos , Taninos/efeitos adversos , Fator de Necrose Tumoral alfa/metabolismoRESUMO
The development of resistance to current antimalarial therapies remains a significant source of concern. To address this risk,newdrugswithnoveltargetsin distinct developmental stages ofPlasmodiumparasites are required. In the current study,we have targetedP. falciparumTubulin(PfTubulin)proteins which represent some of thepotentialdrug targetsfor malaria chemotherapy. PlasmodialMicrotubules (MTs) play a crucial role during parasite proliferation, growth, and transmission, which render them highlydesirabletargets for the development ofnext-generation chemotherapeutics. Towards this,we have evaluated the antimalarial activity ofTubulintargetingcompounds received from theMedicines for Malaria Venture (MMV)"Pathogen Box"against the human malaria parasite,P. falciparumincluding 3D7 (chloroquine and artemisinin sensitive strain), RKL-9 (chloroquine-resistant strain), and R539T (artemisinin-resistant strain). At nanomolar concentrations, the filtered-out compounds exhibitedpronouncedmultistage antimalarialeffects across the parasite life cycle, including intra-erythrocytic blood stages, liver stage parasites, gametocytes, and ookinetes. Concomitantly, these compoundswere found toimpedemale gamete ex-flagellation, thus showingtheir transmission-blocking potential. Target mining of these potent compounds, by combining in silico, biochemical and biophysical assays,implicatedPfTubulinas their moleculartarget, which may possibly act bydisruptingMT assembly dynamics by binding at the interface of α-ßTubulin-dimer.Further, the promising ADME profile of the parent scaffold supported its consideration as a lead compound for further development.Thus, our work highlights the potential of targetingPfTubulin proteins in discovering and developing next-generation, multistage antimalarial agents against Multi-Drug Resistant (MDR) malaria parasites.
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Antimaláricos , Artemisininas , Malária , Acesso à Informação , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Artemisininas/farmacologia , Cloroquina/farmacologia , Humanos , Malária/tratamento farmacológico , Plasmodium falciparum/metabolismo , Tubulina (Proteína)/metabolismoRESUMO
Constant emergence of drug-resistant Plasmodium falciparum warrants urgent need for effective and inexpensive drugs. Herein, phthalimide (Pht) analogs possessing the bioactive scaffolds, benzimidazole and 1,2,3-triazole, were evaluated for in vitro and in vivo anti-plasmodial activity without any apparent hemolysis, or cytotoxicity. Analogs 4(a-e) inhibited the growth of 3D7 and RKL-9 strains at submicromolar concentrations. Defects were observed during parasite egress from or invasion of the red blood cells. Mitochondrial membrane depolarization was measured as one of the causes of cell death. Phts 4(a-e) in combination with artemisinin exhibited two-to three-fold increased efficacy. Biophysical and biochemical analysis suggest that Pht analogs mediate plasmodial growth inhibition by interacting with tubulin protein of the parasite. Lastly, Phts 4(a-e) significantly decreased parasitemia and extended host survival in murine model Plasmodium berghei ANKA infection. Combined, the data indicate that Pht analogs should be further explored, which could offer novel value to the antimalarial drug development pipeline.
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Antimaláricos , Malária , Animais , Antimaláricos/química , Malária/tratamento farmacológico , Malária/parasitologia , Camundongos , Ftalimidas/química , Ftalimidas/farmacologia , Plasmodium berghei , Plasmodium falciparum , Tubulina (Proteína)RESUMO
Cytoskeletal structures of Apicomplexan parasites are important for parasite replication, motility, invasion to the host cell and survival. Apicortin, an Apicomplexan specific protein appears to be a crucial factor in maintaining stability of the parasite cytoskeletal assemblies. However, the function of apicortin, in terms of interaction with microtubules still remains elusive. Herein, we have attempted to elucidate the function of Plasmodium falciparum apicortin by monitoring its interaction with two main components of parasite microtubular structure, α-tubulin-I and ß-tubulin through in silico and in vitro studies. Further, a p25 domain binding generic drug Tamoxifen (TMX), was used to disrupt PfApicortin-tubulin interactions which led to the inhibition in growth and progression of blood stage life cycle of P. falciparum.
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Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Plasmodium falciparum/metabolismo , Proteínas de Protozoários/metabolismo , Tubulina (Proteína)/metabolismo , Microtúbulos/metabolismo , Plasmodium falciparum/crescimento & desenvolvimento , Ligação ProteicaRESUMO
Hijacking of host metabolic status by a pathogen for its regulated dissemination from the host is prerequisite for the propagation of infection. M. tuberculosis secretes an NAD+-glycohydrolase, TNT, to induce host necroptosis by hydrolyzing Nicotinamide adenine dinucleotide (NAD+). Herein, we expressed TNT in macrophages and erythrocytes; the host cells for M. tuberculosis and the malaria parasite respectively, and found that it reduced the NAD+ levels and thereby induced necroptosis and eryptosis resulting in premature dissemination of pathogen. Targeting TNT in M. tuberculosis or induced eryptosis in malaria parasite interferes with pathogen dissemination and reduction in the propagation of infection. Building upon our discovery that inhibition of pathogen-mediated host NAD+ modulation is a way forward for regulation of infection, we synthesized and screened some novel compounds that showed inhibition of NAD+-glycohydrolase activity and pathogen infection in the nanomolar range. Overall this study highlights the fundamental importance of pathogen-mediated modulation of host NAD+ homeostasis for its infection propagation and novel inhibitors as leads for host-targeted therapeutics.
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Alzheimer's disease (AD) is an irreversible and chronic neurological disorder that gradually destroys memory and thinking skills. The research study was designed to investigate the underlying molecular signaling involved in the neuroprotective effects of cyclopentanone derivative i.e., 2-(hydroxyl-(3-nitrophenyl)methyl)cyclopentanone (3NCP) as a therapeutic agent for AD. In this study, In vivo studies were carried out on a well-known 5xFAD mice model using different behavioural test models such as open field, rotarod, Morris water maze (MWM), and Y-maze tests. Furthermore, in vitro cholinesterase inhibition activity assays were carried out. The frontal cortex (FC) and hippocampus (HC) homogenates were tested for the levels/activities of cholinesterases, glutathione (GSH), glutathione S-transferase (GST), and catalase. Furthermore, the hippocampal expression of inflammatory cytokines was observed via RT-PCR and western blot. The results of in vivo studies show an enhancement in the learning behavior. The 3NCP treatment reduced latency time in MWM and Y-maze tests, also increase spontaneous alternation indicate significant effect of 3NCP on memory. Furthermore, open field and rotarod studies revealed that 3NCP does not cause motor coordination deficit. The results of the in vitro studies revealed that the IC50 values of the 3NCP against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) were 16.17 and 20.51 µg/mL, respectively. This decline in AChE and BChE was further supported by ex vivo studies. Further, the 3NCP mitigates the GSH level, GST, and catalase activities in HC and FC. The mRNA and protein expression of inflammatory cytokines (IL-1ß, IL-6, TNF-α) markedly declined in RT-PCR and western blotting. The results of the current study conclusively demonstrate that 3NCP reduces oxidative stress and mitigates neuroinflammation in 5xFAD mice, implying that 3NCP may be a potential therapeutic candidate for AD treatment in the future.
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Oxidative fast pyrolysis of sawdust was performed in a pilot scale fluidized bed system (3â¯kg/h) under stabilized experimental conditions (0.20 equivalence ratio and 550⯰C). Experiments were performed in non-catalytic and catalytic (ZSM-5) mode. During non-catalytic fast pyrolysis, bio-oil (â¼38â¯wt%), bio-char (â¼12â¯wt%) and pyro-gas (â¼50â¯wt%) were obtained; in contrast, for catalytic fast pyrolysis bio-oil, bio-char and pyro-gas yields were â¼44â¯wt%, â¼4â¯wt% and â¼52â¯wt% respectively. The obtained bio-oil was characterized through CHNSO, NMR (1H and 13C NMR), FT-IR and GC-MS techniques. GC-MS analysis of the bio-oil shows it is a mixture of â¼21 chemical compounds. Furthermore, NMR (1H and 13C NMR) and FT-IR results indicates presence of hydrocarbon, alcohol, phenol and aldehyde in the bio-oil. The TGA of bio-char shows that it is stable up to 950⯰C. The activation energies (Ea) of sawdust and bio-char are found to be 112.3â¯kJ/mol and 46.92â¯kJ/mol respectively. FT-IR analysis of bio-char clearly revealed removal of functionalized organic compounds during devolatilization of sawdust. In addition, GC analysis of pyro-gas suggests that it is a mixture of N2 (35.55â¯vol%), CO (34.49â¯vol%), CO2 (16.80â¯vol%), H2 (4.54â¯vol%), O2 (4.25â¯vol%), and CH4 (4.41â¯vol%).
Assuntos
Biocombustíveis , Pirólise , Biocombustíveis/análise , Biomassa , Temperatura Alta , Estresse Oxidativo , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
BRCA1 promotes error-free, homologous recombination-mediated repair (HRR) of DNA double-stranded breaks (DSBs). When excessive and uncontrolled, BRCA1 HRR activity promotes illegitimate recombination and genome disorder. We and others have observed that the BRCA1-associated protein RAP80 recruits BRCA1 to postdamage nuclear foci, and these chromatin structures then restrict the amplitude of BRCA1-driven HRR. What remains unclear is how this process is regulated. Here we report that both BRCA1 poly-ADP ribosylation (PARsylation) and the presence of BRCA1-bound RAP80 are critical for the normal interaction of BRCA1 with some of its partners (e.g., CtIP and BACH1) that are also known components of the aforementioned focal structures. Surprisingly, the simultaneous loss of RAP80 and failure therein of BRCA1 PARsylation results in the dysregulated accumulation in these foci of BRCA1 complexes. This in turn is associated with the intracellular development of a state of hyper-recombination and gross chromosomal disorder. Thus, physiological RAP80-BRCA1 complex formation and BRCA1 PARsylation contribute to the kinetics by which BRCA1 HRR-sustaining complexes normally concentrate in nuclear foci. These events likely contribute to aneuploidy suppression.