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1.
JNMA J Nepal Med Assoc ; 62(270): 72-75, 2024 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-38409991

RESUMEN

Introduction: The majority of trauma-related deaths occur in low- and middle-income countries; however, limited data exists in these settings related to injury types and severity. The prevalence of trauma similar to our setting was less estimated. This study aimed to find the prevalence of traumatic injury among patients presented to the department of emergency medicine of a tertiary care centre. Methods: This is a descriptive cross-sectional study conducted among patients presented to the Department of Emergency Medicine from 15 September 2021 to 14 September 2022. Ethical approval was taken from the Institutional Review Committee. World Health Organization trauma minimum data set, injury mechanism, types and patient disposition data were collected and injury severity scores were calculated. A convenience sampling method was used. The point estimate was calculated at a 95% Confidence Interval. Results: Among 47,825 patients, 1,524 (3.19%) (3.03-3.34, 95% Confidence Interval) patients presented with a traumatic injury. A total of 967 (63.45%) were males and had a median age of 30 years (Interquartile range: 25). Most injuries were caused by falls 650 (42.65%), followed by road traffic accidents 411 (26.97%). A majority had minor Injury Severity Scores 1280 (83.99%). Conclusions: The prevalence of traumatic injury among patients presenting to emergency was found to be lower than other studies done in similar settings. Keywords: emergency care; injuries and wounds; injury severity score; trauma unit.


Asunto(s)
Servicios Médicos de Urgencia , Medicina de Emergencia , Masculino , Humanos , Adulto , Femenino , Centros de Atención Terciaria , Estudios Transversales , Proyectos de Investigación
2.
Ann Med Surg (Lond) ; 85(12): 6222-6226, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38098590

RESUMEN

Introduction and importance: A small bowel perforation occurring in isolation as a result of blunt abdominal trauma (BAT) is a rare event, especially in pediatric patients. The unusual presentation and lack of distinct clinical indications can pose a challenge in promptly diagnosing this condition. This study seeks to underscore the importance of early detection and immediate surgical intervention when dealing with small bowel perforations following BAT. Case presentation: A 13-year-old girl arrived at the emergency department after falling from a cliff. Initial evaluations, including a physical examination and imaging studies, did not uncover any notable irregularities. Nevertheless, the persistent abdominal discomfort and pain prompted further concerns. A contrast-enhanced computed tomography scan was performed, confirming ileal perforation. The patient subsequently underwent exploratory laparotomy, which resulted in successful surgical treatment. Clinical discussion: BAT causes increased intraluminal pressure, leading to blowout perforation of the small bowel. Diagnosis can be challenging, particularly in the absence of immediate symptoms or conclusive radiographic findings. Close observation and repeated examinations are essential to detect delayed perforations. Early surgical intervention within 12 h of injury has been shown to significantly reduce complications and mortality rates. Conclusion: Isolated small bowel perforation is a rare occurrence in pediatric patients, and timely diagnosis and surgical intervention are crucial for favorable outcomes. Diagnostic imaging, like contrast-enhanced computerized tomography, helps identify the condition when clinical findings are inconclusive. Comprehensive counseling is essential for patients and their families to understand potential risks and intervention needs, ensuring appropriate management, and treatment delays.

3.
Ann Med Surg (Lond) ; 85(10): 5196-5199, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37811019

RESUMEN

Introduction: Lung cancer is a major contributor of burden of disease globally. Early diagnosis plays a crucial role in determining the patient's prognosis. However, diagnostic constraints and healthcare-seeking behavior in rural areas contribute to the increased mortality and morbidity associated with this disease. Case presentation: The authors present a case that came in with mood and personality changes who was diagnosed with lung cancer with metastasis in the brain and did not seek health care services despite a prolonged duration of her neurocognitive symptoms. Clinical discussion: Rural communities face multiple barriers to early diagnosis and treatment, including healthcare-seeking behavior. It is crucial to develop policies aimed at addressing these barriers in order to enhance the health status of rural Nepal. Conclusion: The presentation of lung cancer with atypical symptoms can contribute to delays in diagnosis and treatment, ultimately impacting the overall prognosis of the patient. Late presentation to healthcare centers further exacerbates the burden of the disease, emphasizing the critical importance of proper healthcare-seeking behavior.

4.
High Alt Med Biol ; 24(3): 201-208, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37306966

RESUMEN

Small, Elan, Caleb Phillips, William Bunzel, Lakota Cleaver, Nishant Joshi, Laurel Gardner, Rony Maharjan, and James Marvel. Prior ambulatory mild coronavirus disease 2019 does not increase risk of acute mountain sickness. High Alt Med Biol. 24:201-208, 2023. Background: Given its long-term morbidity, understanding how prior coronavirus disease 2019 (COVID-19) may affect acute mountain sickness (AMS) susceptibility is important for preascent risk stratification. The objective of this study was to examine if prior COVID-19 impacts risk of AMS. Materials and Methods: This was a prospective observational study conducted in Lobuje (4,940 m) and Manang (3,519 m), Nepal, from April to May 2022. AMS was defined by the 2018 Lake Louise Questionnaire criteria. COVID-19 severity was defined using the World Health Organization-developed criteria. Results: In the Lobuje cohort of 2,027, 46.2% of surveyed individuals reported history of COVID-19, with 25.7% AMS point-prevalence. There was no significant relationship between prior ambulatory mild COVID-19 and AMS (p = 0.6) or moderate AMS (p = 1.0). In the Manang cohort of 908, 42.8% reported history of COVID-19, with 14.7% AMS point-prevalence. There was no significant relationship between prior ambulatory mild COVID-19 and AMS (p = 0.3) or moderate AMS (p = 0.4). Average months since COVID-19 was 7.4 (interquartile range [IQR] 3-10) for Lobuje, 6.2 (IQR 3-6) for Manang. Both cohorts rarely exhibited moderate COVID-19 history. Conclusions: Prior ambulatory mild COVID-19 was not associated with increased risk of AMS and should not preclude high-altitude travel.


Asunto(s)
Mal de Altura , COVID-19 , Humanos , Mal de Altura/etiología , COVID-19/complicaciones , Enfermedad Aguda , Prevalencia , Encuestas y Cuestionarios , Altitud
5.
Cell Death Discov ; 9(1): 160, 2023 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-37173329

RESUMEN

Despite several initiatives to subside the global malaria burden, the spread of artemisinin-resistant parasites poses a big threat to malaria elimination. Mutations in PfKelch13 are predictive of ART resistance, whose underpinning molecular mechanism remains obscure. Recently, endocytosis and stress response pathways such as the ubiquitin-proteasome machinery have been linked to artemisinin resistance. With Plasmodium, however, ambiguity persists regarding a role in ART resistance for another cellular stress defence mechanism called autophagy. Therefore, we investigated whether, in the absence of ART treatment, basal autophagy is augmented in PfK13-R539T mutant ART-resistant parasites and analyzed whether PfK13-R539T endowed mutant parasites with an ability to utilize autophagy as a pro-survival strategy. We report that in the absence of any ART treatment, PfK13-R539T mutant parasites exhibit increased basal autophagy compared to PfK13-WT parasites and respond aggressively through changes in autophagic flux. A clear cytoprotective role of autophagy in parasite resistance mechanism is evident by the observation that a suppression of PI3-Kinase (PI3K) activity (a master autophagy regulator) rendered difficulty in the survival of PfK13-R539T ART-resistant parasites. In conclusion, we now show that higher PI3P levels reported for mutant PfKelch13 backgrounds led to increased basal autophagy that acts as a pro-survival response to ART treatment. Our results highlight PfPI3K as a druggable target with the potential to re-sensitize ART-resistant parasites and identify autophagy as a pro-survival function that modulates ART-resistant parasite growth.

6.
Microbiol Spectr ; : e0276622, 2023 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-36744922

RESUMEN

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.

7.
J Biomol Struct Dyn ; 41(19): 9462-9475, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-36351236

RESUMEN

Intraerythrocytic stages of Plasmodium falciparum responsible for all clinical manifestations of malaria are regulated by array of signalling cascades that represent attractive targets for antimalarial therapy. G-protein coupled receptors (GPCRs) are druggable targets in the treatment of various pathological conditions, however, there is limited understanding about the role of GPCRs in malaria pathogenesis. In Plasmodium, serpentine receptors (PfSR1, PfSR10, PfSR12 and PfSR25) with GPCR-like membrane topology have been reported with the finite knowledge about their potential as antimalarial targets. We analyzed the localization of these receptors in malaria parasite by immunofluorescence assays. All four receptors were expressed in blood stages with PfSR12 expressing more in late intraerythrocytic stages. Further, we evaluated the druggability of PfSR12 using FDA-approved P2Y purinergic receptor antagonist, Prasugrel and its active metabolite R138727, which is proposed to be specific towards PfSR12. Interestingly, biophysical analysis indicated strong binding between PfSR12 and R138727 as compared to the prodrug Prasugrel. This binding interaction was further confirmed by thermal shift assay. Treatment of parasite with Prasugrel and R138727 resulted in growth inhibition of P. falciparum indicating an important role of purinergic signalling and PfSR12 in parasite survival. Next, progression studies indicated the inhibitory effect of Prasugrel begins in late erythrocyte stages corroborating with PfSR12 expression at these stages. Furthermore, Prasugrel also blocked in vivo growth of malaria parasite in a mouse experimental model. This study indicates the presence of P2Y type of purinergic signalling in growth and development of malaria parasite and suggests PfSR12, putative purinergic receptor druggability through Prasugrel.Communicated by Ramaswamy H. Sarma.


Asunto(s)
Antimaláricos , Malaria Falciparum , Malaria , Animales , Ratones , Plasmodium falciparum , Antimaláricos/metabolismo , Clorhidrato de Prasugrel/metabolismo , Clorhidrato de Prasugrel/farmacología , Clorhidrato de Prasugrel/uso terapéutico , Malaria Falciparum/tratamiento farmacológico , Malaria/tratamiento farmacológico , Receptores Purinérgicos/metabolismo , Receptores Purinérgicos/uso terapéutico , Receptores Acoplados a Proteínas G/metabolismo , Eritrocitos/metabolismo , Antagonistas Purinérgicos/metabolismo , Antagonistas Purinérgicos/farmacología , Antagonistas Purinérgicos/uso terapéutico , Proteínas Protozoarias/metabolismo
8.
Antimicrob Agents Chemother ; 66(12): e0039222, 2022 12 20.
Artículo en Inglés | MEDLINE | ID: mdl-36374050

RESUMEN

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.


Asunto(s)
Antimaláricos , Artemisininas , Malaria Falciparum , Malaria , Humanos , Antimaláricos/farmacología , Antimaláricos/uso terapéutico , Ciclosporina/farmacología , Ciclosporina/uso terapéutico , Reposicionamiento de Medicamentos , Resistencia a Medicamentos , Artemisininas/farmacología , Artemisininas/uso terapéutico , Malaria/tratamiento farmacológico , Malaria Falciparum/tratamiento farmacológico , Plasmodium falciparum
9.
Front Cell Infect Microbiol ; 12: 803048, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35601095

RESUMEN

Visceral leishmaniasis (VL) and post kala-azar dermal leishmaniasis (PKDL) affect most of the poor populations worldwide. The current treatment modalities include liposomal formulation or deoxycholate salt of amphotericin B, which has been associated with various complications and severe side effects. Encouraged from the recent marked antimalarial effects from plant-derived glycosides, in this study, we have exploited a green chemistry-based approach to chemically synthesize a library of diverse glycoside derivatives (Gly1-12) and evaluated their inhibitory efficacy against the AG83 strain of Leishmania donovani. Among the synthesized glycosides, the in vitro inhibitory activity of Glycoside-2 (Gly2) (1.13 µM IC50 value) on L. donovani promastigote demonstrated maximum cytotoxicity with ~94% promastigote death as compared to amphotericin B that was taken as a positive control. The antiproliferative effect of Gly2 on promastigote encouraged us to analyze the structure-activity relationship of Gly2 with Gp63, a zinc metalloprotease that majorly localizes at the surface of the promastigote and has a role in its development and multiplication. The result demonstrated the exceptional binding affinity of Gly2 toward the catalytic domain of Gp63. These data were thereafter validated through cellular thermal shift assay in a physiologically relevant cellular environment. Mechanistically, reduced multiplication of promastigotes on treatment with Gly2 induces the destabilization of redox homeostasis in promastigotes by enhancing reactive oxygen species (ROS), coupled with depolarization of the mitochondrial membrane. Additionally, Gly2 displayed strong lethal effects on infectivity and multiplication of amastigote inside the macrophage in the amastigote-macrophage infection model in vitro as compared to amphotericin B treatment. Gp63 is also known to bestow protection against complement-mediated lysis of parasites. Interestingly, Gly2 treatment enhances the complement-mediated lysis of L. donovani promastigotes in serum physiological conditions. In addition, Gly2 was found to be equally effective against the clinical promastigote forms of PKDL strain (IC50 value of 1.97 µM); hence, it could target both VL and PKDL simultaneously. Taken together, this study reports the serendipitous discovery of Gly2 with potent antileishmanial activity and proves to be a novel chemotherapeutic prototype against VL and PKDL.


Asunto(s)
Antiprotozoarios , Leishmania donovani , Leishmaniasis Visceral , Anfotericina B/farmacología , Antiprotozoarios/farmacología , Antiprotozoarios/uso terapéutico , Glicósidos , Humanos , Leishmaniasis Visceral/tratamiento farmacológico , Metaloproteasas
10.
J Biomol Struct Dyn ; 40(11): 5159-5174, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-33416018

RESUMEN

Malaria infection caused by Plasmodium falciparum is majorly responsible for millions of deaths in humans every year. Moreover, a rapid increase in resistance to existing drugs has posed an urgent need for new anti-malarials. Herein, we report the highly potent anti-malarial activity of benzopyrano(4,3-b)benzopyran derivatives, inspired from naturally occurring dependensin against chloroquine (CQ) sensitive and resistant P. falciparum strains. Chemically synthesized, four dependensin analogs 85(A-D) exhibited growth inhibition at nanomolar concentrations ranging from 63.96 to 725.8 nM by blocking the parasite development at the ring and early trophozoite stages. The growth inhibitory activity of dependensin analogs was correlated with their anti-plasmodial lactate dehydrogenase activity by computational analysis. Molecular docking, 50 ns simulation and a 2D-Quantitative Structure-Activity Relationship (2D-QSAR) modelling revealed the interaction with their putative target P. falciparum lactate dehydrogenase (PfLDH). Here, developing the predictive 2D descriptors such as thermodynamic, spatial, electronic, and topological with multiple linear regression analysis (MLRA), the structural requirements for potent and selective PfLDH inhibitory activity has been identified. The strong binding of compound 85D to the catalytic Nicotinamide adenine dinucleotide (NADH) binding pocket of the PfLDH further supported the PfLDH targeting potential of dependensin analogs. Overall, this study revealed a highly potent anti-malarial activity of benzopyrano(4,3-b)benzopyran derivatives with their putative anti-PfLDH activity.Communicated by Ramaswamy H. Sarma.


Asunto(s)
Antimaláricos , Benzopiranos , L-Lactato Deshidrogenasa , Plasmodium falciparum , Antimaláricos/química , Antimaláricos/farmacología , Benzopiranos/farmacología , L-Lactato Deshidrogenasa/antagonistas & inhibidores , Simulación del Acoplamiento Molecular , Plasmodium falciparum/efectos de los fármacos , Plasmodium falciparum/enzimología
11.
Sci Rep ; 11(1): 4688, 2021 02 25.
Artículo en Inglés | MEDLINE | ID: mdl-33633135

RESUMEN

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.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Plasmodium falciparum/metabolismo , Proteínas Protozoarias/metabolismo , Tubulina (Proteína)/metabolismo , Microtúbulos/metabolismo , Plasmodium falciparum/crecimiento & desarrollo , Unión Proteica
12.
Cell Death Discov ; 7(1): 10, 2021 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-33441562

RESUMEN

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.

13.
Int J Mol Sci ; 21(17)2020 Aug 26.
Artículo en Inglés | MEDLINE | ID: mdl-32859024

RESUMEN

Apicomplexan parasites, through their motor machinery, produce the required propulsive force critical for host cell-entry. The conserved components of this so-called glideosome machinery are myosin A and myosin A Tail Interacting Protein (MTIP). MTIP tethers myosin A to the inner membrane complex of the parasite through 20 amino acid-long C-terminal end of myosin A that makes direct contacts with MTIP, allowing the invasion of Plasmodium falciparum in erythrocytes. Here, we discovered through screening a peptide library, a de-novo peptide ZA1 that binds the myosin A tail domain. We demonstrated that ZA1 bound strongly to myosin A tail and was able to disrupt the native myosin A tail MTIP complex both in vitro and in vivo. We then showed that a shortened peptide derived from ZA1, named ZA1S, was able to bind myosin A and block parasite invasion. Overall, our study identified a novel anti-malarial peptide that could be used in combination with other antimalarials for blocking the invasion of Plasmodium falciparum.


Asunto(s)
Antimaláricos/farmacología , Proteínas de la Membrana/metabolismo , Miosina Tipo IIA no Muscular/metabolismo , Péptidos/farmacología , Plasmodium falciparum/crecimiento & desarrollo , Secuencias de Aminoácidos , Antimaláricos/química , Sitios de Unión , Evaluación Preclínica de Medicamentos , Eritrocitos/parasitología , Ensayos Analíticos de Alto Rendimiento , Humanos , Proteínas de la Membrana/química , Modelos Moleculares , Complejos Multiproteicos/efectos de los fármacos , Miosina Tipo IIA no Muscular/química , Biblioteca de Péptidos , Péptidos/química , Plasmodium falciparum/efectos de los fármacos , Plasmodium falciparum/metabolismo , Unión Proteica , Proteínas Protozoarias/química , Proteínas Protozoarias/metabolismo
14.
Front Microbiol ; 11: 656, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32351484

RESUMEN

Understanding the dynamics of host innate immune responses against a pathogen marks the first step toward developing intervention strategies against the pathogen. The cytosolic pattern recognition receptor retinoic acid-inducible gene I (RIG-I) has been shown to be the major innate immune sensor for hepatitis E virus (HEV). Here, we show that HEV capsid protein (ORF2), a 660 amino acid long protein, interferes with the RIG-I signaling. Interestingly, only the full length ORF2 protein but not the 112-608 ORF2 protein inhibited RIG-I dependent interferon response. Both synthetic agonist and virus induced RIG-I activation was modulated by ORF2. Interference of interferon response was confirmed by reporter assays involving different interferon inducible promoters, qRT PCR, ELISA, and immunofluorescence microscopy. Neither glycosylation nor dimerization of the ORF2 protein had any effect on the observed inhibition. Further analyses revealed that the ORF2 protein antagonized Toll-like receptor (TLR) pathways as well. ORF2 inhibited signaling by RIG-I and TLR adapters, IPS-1, MyD88, and TRIF but was unable to inhibit activation by ectopically expressed IRF3 suggesting that it may be acting at a site upstream of IRF3 and downstream of adapter proteins. Our data uncover a new mechanism by which HEV may interfere with the host antiviral signaling.

15.
FEBS Open Bio ; 9(2): 248-264, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30761251

RESUMEN

Lipid-based palmitoylation is a post-translation modification (PTM) which acts as a biological rheostat in life cycle progression of a deadly human malaria parasite, Plasmodium falciparum. P. falciparum palmitoylation is catalyzed by 12 putative palmitoyl acyl-transferase enzymes containing the conserved DHHC-CRD (DHHC motif within a cysteine-rich domain) which can serve as a druggable target. However, the paucity of high-throughput assays has impeded the design of drugs targeting palmitoylation. We have developed a novel strategy which involves engineering of Escherichia coli, a PTM-null system, to enforce ectopic expression of palmitoyl acyl-transferase in order to study Plasmodium-specific palmitoylation and screening of inhibitors. In this study, we have developed three synthetic E. coli strains expressing Plasmodium-specific DHHC proteins (PfDHHC7/8/9). These cells were used for validating acyl-transferase activity via acyl-biotin exchange (ABE) and clickable chemistry methods. E. coli proteome was found to be palmitoylated in PfDHHC-expressing clones, suggesting that plasmodium DHHC can catalyze palmitoylation of E. coli proteins. Upon treatment with generic inhibitor 2-bromopalmitate (2-BMP), a predominant reduction in palmitic acid incorporation is detected. Overall, these findings suggest that synthetic E. coli strains expressing PfDHHCs can enforce global palmitoylation in the E. coli proteome. Interestingly, this finding was corroborated by our in silico palmitoylome profiling, which revealed that out of the total E. coli proteome, 108 proteins were predicted to be palmitoylated as represented by the presence of three cysteine consensus motifs (cluster type I, II, III). In summary, our study reports a proof of concept for screening of chemotherapeutics targeting the palmitoylation machinery using a high-throughput screening platform.


Asunto(s)
Aciltransferasas/antagonistas & inhibidores , Inhibidores Enzimáticos/farmacología , Escherichia coli/efectos de los fármacos , Ingeniería Genética , Ensayos Analíticos de Alto Rendimiento , Ácido Palmítico/antagonistas & inhibidores , Plasmodium falciparum/efectos de los fármacos , Aciltransferasas/metabolismo , Biocatálisis , Química Clic , Inhibidores Enzimáticos/química , Escherichia coli/genética , Escherichia coli/metabolismo , Simulación del Acoplamiento Molecular , Ácido Palmítico/metabolismo , Plasmodium falciparum/crecimiento & desarrollo , Plasmodium falciparum/metabolismo
16.
Sci Rep ; 7(1): 5816, 2017 07 19.
Artículo en Inglés | MEDLINE | ID: mdl-28725041

RESUMEN

Hepatitis C virus (HCV) is a global pathogen and infects more than 185 million individuals worldwide. Although recent development of direct acting antivirals (DAA) has shown promise in HCV therapy, there is an urgent need for the development of more affordable treatment options. We initiated this study to identify novel inhibitors of HCV through screening of compounds from the National Cancer Institute (NCI) diversity dataset. Using cell-based assays, we identified NSC-320218 as a potent inhibitor against HCV with an EC50 of 2.5 µM and CC50 of 75 µM. The compound inhibited RNA dependent RNA polymerase (RdRp) activity of all six major HCV genotypes indicating a pan-genotypic effect. Limited structure-function analysis suggested that the entire molecule is necessary for the observed antiviral activity. However, the compound failed to inhibit HCV NS5B activity in vitro, suggesting that it may not be directly acting on the NS5B protein but could be interacting with a host protein. Importantly, the antiviral compound also inhibited dengue virus and hepatitis E virus replication in hepatocytes. Thus, our study has identified a broad-spectrum antiviral therapeutic agent against multiple viral infections.


Asunto(s)
Antivirales/farmacología , Evaluación Preclínica de Medicamentos , Inhibidores Enzimáticos/farmacología , Hepacivirus/enzimología , ARN Polimerasa Dependiente del ARN/antagonistas & inhibidores , Antivirales/química , Línea Celular Tumoral , Virus del Dengue/efectos de los fármacos , Virus del Dengue/fisiología , Inhibidores Enzimáticos/química , Genotipo , Hepacivirus/efectos de los fármacos , Hepacivirus/genética , Hepacivirus/fisiología , Humanos , ARN Polimerasa Dependiente del ARN/metabolismo , Recombinación Genética/genética , Replicón/genética , Bibliotecas de Moléculas Pequeñas , Relación Estructura-Actividad , Replicación Viral/efectos de los fármacos
17.
J Periodontol ; 88(9): 823-829, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28548883

RESUMEN

BACKGROUND: Chronic prostatitis (CPr) and benign prostatic hyperplasia (BPH) are complex inflammatory conditions for which etiologic determinants are still poorly defined. Periodontitis is caused by subgingival colonizing bacteria in the oral cavity. The causal effect of periodontal disease on prostatic inflammation has not been established. The purpose of this study is to isolate oral pathogens from expressed prostatic secretions of patients with periodontal disease and CPr or BPH. METHODS: Twenty-four men diagnosed with CPr/BPH participated in the study. A complete periodontal examination consisting of probing depth, bleeding on probing, tooth mobility, gingival index, and plaque index was performed on the men, and prostatic secretion was collected for the study. Dental plaque and prostatic secretion samples were used for analysis of bacterial DNA for Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Treponema denticola (Td), and Escherichia coli using reverse transcription-polymerase chain reaction. RESULTS: Six patients were diagnosed with severe, seven with moderate, and four with mild chronic periodontitis. Seventeen of 24 (70.8%) of the prostatic secretion samples showed one or more of the studied oral pathogens. Nine of 10 BPH and eight of 14 patients with CPr had at least one oral pathogen in their prostatic secretions. Pg was found in both prostatic secretion and plaque samples in six of 17 (35.3%) patients, Td was found in both samples in seven of 15 (46.7%) patients, and E. coli was found in both samples in three of 15 (20%) patients. Pi was detected in all dental plaque samples but not in the prostatic secretion. CONCLUSION: An association between chronic inflammatory prostate and periodontal diseases has been demonstrated by the presence of similar bacterial DNA in both prostatic secretion and subgingival dental plaque from the same individual.


Asunto(s)
Placa Dental/microbiología , Periodontitis/microbiología , Hiperplasia Prostática/microbiología , Prostatitis/microbiología , Adulto , Anciano , Anciano de 80 o más Años , Escherichia coli/aislamiento & purificación , Humanos , Masculino , Persona de Mediana Edad , Índice Periodontal , Porphyromonas gingivalis/aislamiento & purificación , Prevotella intermedia/aislamiento & purificación , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Treponema denticola/aislamiento & purificación
18.
J Periodontol ; 81(6): 864-9, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20450358

RESUMEN

BACKGROUND: Prostate-specific antigen (PSA) is an inflammatory marker produced by the epithelial cells of the prostate acini. In the presence of inflammation or malignancy of the prostate, PSA levels are > or = 4 ng/ml. This preliminary study was conducted to evaluate any association between periodontitis and PSA levels in chronic prostatitis patients. METHODS: Thirty-five subjects who underwent prostate biopsy because of abnormal findings on digital rectal examination or elevated PSA (> or = 4 ng/ml) participated in the study. Plaque and gingival indices, bleeding on probing, probing depth, and clinical attachment level (CAL) were determined. Two-sided independent sample t tests assessed any significant differences in the PSA levels between and among the groups of prostatitis and periodontitis. RESULTS: Mean PSA levels were significantly higher (P = 0.04) in subjects with moderate/severe prostate inflammation than those with none/mild (8.8 +/- 5.8 versus 5.7 +/- 3.1 ng/ml). Subjects with CAL > or = 2.7 mm had higher but not statistically significant PSA levels than those with CAL <2.7 mm (7.7 +/- 5.2 versus 5.7 +/- 3.2 ng/ml), respectively. Individuals having both moderate/severe prostatitis and CAL > or = 2.7 mm (10.8 +/- 7 ng/ml) had significantly higher mean PSA levels (P = 0.05) than those with neither condition (5.6 +/- 3.7 ng/ml) nor only CAL > or = 2.7 mm (5.7 +/- 2.4 ng/ml) or moderate/severe prostatitis (6 +/- 1.9 ng/ml). CONCLUSION: Subjects having comorbidity of CAL > or = 2.7 mm and moderate/severe prostatitis have higher PSA levels than those with either condition alone.


Asunto(s)
Pérdida de la Inserción Periodontal/complicaciones , Antígeno Prostático Específico/sangre , Prostatitis/complicaciones , Distribución de Chi-Cuadrado , Enfermedad Crónica , Índice de Placa Dental , Humanos , Masculino , Pérdida de la Inserción Periodontal/sangre , Índice Periodontal , Proyectos Piloto , Prostatitis/sangre , Estadísticas no Paramétricas
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