RESUMO
A relationship between cholesterol levels and Niemann-Pick C1-Like 1 (NPC1L1) polymorphisms in diverse populations was found in previous studies. However, relevant research on this association in the Korean population is relatively scarce. Therefore, the current study sought to examine the correlation between the NPC1L1 rs217434 A > G polymorphism and clinical as well as biochemical variables pertaining to dyslipidemia in the Korean population. This cross-sectional single-center study included 1404 Korean subjects aged 20-86 years, grouped based on dyslipidemia presence (normal and dyslipidemia) and genotype (AA or AG). After adjusting for sex and age, it was discovered that the dyslipidemia group's BMI, diastolic blood pressure, glucose-related indicators, lipid profile, high-sensitivity C-reactive protein (hs-CRP), and parameters of oxidative stress were considerably different from the normal group's values. When grouped according to genotype, individuals in the AG group exhibited greater total cholesterol, low-density lipoprotein cholesterol, hs-CRP, and 8-epi-prostaglandin F2α in comparison to those in the AA group. Moreover, individuals with dyslipidemia and the AG genotype exhibited unfavorable outcomes for lipid profiles, markers related to glucose and inflammation, and markers of oxidative stress. This study provided evidence for a relationship between the NPC1L1 rs217434 A > G genotype and dyslipidemia in the Korean population, which highlights the potential of the NPC1L1 rs217434 A > G genotype as an early predictor of dyslipidemia.
RESUMO
Mounting evidence indicates that the gut microbiota influences the neurodevelopment and behavior of insects through the gut-brain axis. However, it is currently unclear whether the gut microbiota affect the head profiles and immune pathway in pests. Here, we find that gut bacteria is essential for the immune and neural development of adult Spodoptera frugiperda, which is an extremely destructive agricultural pest worldwide. 16 S rRNA sequencing analysis showed that antibiotics exposure significantly disturbed the composition and diversity of gut bacteria. Further transcriptomic analysis revealed that the adult head transcripts were greatly affected by gut dysbacteriosis, and differently expression genes critical for brain and neural development including A4galt, Tret1, nsun4, Galt, Mitofilin, SLC2A3, snk, GABRB3, Oamb and SLC6A1 were substantially repressed. Interestingly, the dysbacteriosis caused sex-specific differences in immune response. The mRNA levels of pll (serine/threonine protein kinase Pelle), PGRP (peptidoglycan-sensing receptor), CECA (cecropin A) and CECB (cecropin B) involved in Toll and Imd signaling pathway were drastically decreased in treated male adults' heads but not in female adults; however, genes of HIVEP2, ZNF131, inducible zinc finger protein 1-like and zinc finger protein 99-like encoding zinc-finger antiviral protein (ZAP) involved in the interferon (IFNα/ß) pathway were significantly inhibited in treated female adults' heads. Collectively, these results demonstrate that gut microbiota may regulate head transcription and impact the S. frugiperda adults' heads through the immune pathway in a sex-specific manner. Our finding highlights the relationship between the gut microbiota and head immune systems of S. frugiperda adults, which is an astonishing similarity with the discoveries of other animals. Therefore, this is the basis for further research to understand the interactions between hosts and microorganisms via the gut-brain axis in S. frugiperda and other insects.
Assuntos
Disbiose , Transcriptoma , Masculino , Animais , Feminino , Spodoptera/microbiologia , Disbiose/veterinária , Perfilação da Expressão Gênica , Imunidade , LarvaRESUMO
BACKGROUND: Dyslipidemia is important because of its association with various metabolic complications. Numerous studies have sought to obtain scientific evidence for managing dyslipidemia patients. OBJECTIVES: This study aims to identify differences in the nutritional traits of dyslipidemia subjects based on metabolite patterns. METHODS: Dyslipidemia (n = 73) and control (n = 80) subjects were included. Dyslipidemia was defined as triglycerides ≥200 mg/dL, total cholesterol ≥240 mg/dL, low density lipoprotein cholesterol ≥160 mg/dL, high-density lipoprotein cholesterol <40 mg/dL (men) or 50 mg/dL (women), or lipid-lowering medicine use. Nontargeted metabolomics based on ultra-high performance liquid chromatography-mass spectrometry identified plasma metabolites, and K-means clustering was used to reconstitute groups based on the similarity of metabolomic patterns across all subjects. Then, with eXtreme Gradient Boosting, metabolites significantly contributing to the new grouping were selected. Statistical analysis was conducted to analyze traits demonstrating appreciable differences between the groups. RESULTS: Dyslipidemia subjects were divided into 2 groups based on whether they were (n = 24) or were not (n = 56) in a similar metabolic state as the controls by K-means clustering. The considerable contribution of 4 metabolites (3-hydroxybutyrylcarnitine, 2-octenal, 1,3,5-heptatriene, and 5ß-cholanic acid) to this new subset of dyslipidemia was confirmed by eXtreme Gradient Boosting. Furthermore, fiber intake was significantly higher in dyslipidemia subjects whose metabolic state was similar to that of the control than in the dissimilar group (P = 0.002). Moreover, significant correlations were observed between the 4 metabolites and fiber intake. Regression analysis determined that the ideal cutoff for fiber intake was 17.28 g/d. CONCLUSIONS: Dyslipidemia patients who consume 17.28 g/d or more of dietary fiber may maintain similar metabolic patterns to healthy individuals, with substantial effects on the changes in the concentrations of 4 metabolites. Our findings could be applied to developing dietary guidelines for dyslipidemia patients.
Assuntos
Dislipidemias , Masculino , Humanos , Feminino , Estudos Transversais , Metabolômica , HDL-Colesterol , Fibras na DietaRESUMO
Efforts to develop vaccines against malaria represent a major research target. The observations that 1) sterile protection can be obtained when the host is exposed to live parasites and 2) the immunity against blood stage parasite is principally mediated by protective antibodies suggest that a protective vaccine is feasible. However, only a small number of proteins have been investigated so far and most of the Plasmodium proteome has yet to be explored. To date, only few immunodominant antigens have emerged for testing in clinical trials but no formulation has led to substantial protection in humans. The nature of parasite molecules associated with protection remains elusive. Here, immunomic screening of mice immune sera with different protection efficiencies against the whole parasite proteome allowed us to identify a large repertoire of antigens validated by screening a library expressing antigens. The calculation of weighted scores reflecting the likelihood of protection of each antigen using five predictive criteria derived from immunomic and proteomic data sets, highlighted a priority list of protective antigens. Altogether, the approach sheds light on conserved antigens across Plasmodium that are amenable to targeting by the host immune system upon merozoite invasion and blood stage development. Most of these antigens have preliminary protection data but have not been widely considered as candidate for vaccine trials, opening new perspectives that overcome the limited choice of immunodominant, poorly protective vaccines currently being the focus of malaria vaccine researches.
Assuntos
Antígenos de Protozoários/imunologia , Malária/imunologia , Malária/prevenção & controle , Animais , Antígenos de Protozoários/química , Células CHO , Cricetinae , Cricetulus , Membrana Eritrocítica/metabolismo , Soros Imunes , Malária/sangue , Merozoítos/crescimento & desenvolvimento , Merozoítos/imunologia , Camundongos Endogâmicos BALB C , Parasitos/crescimento & desenvolvimento , Plasmodium/crescimento & desenvolvimento , Plasmodium/imunologia , Desnaturação Proteica , Domínios Proteicos , Proteômica , Proteínas de Protozoários/química , Proteínas de Protozoários/metabolismo , Reprodutibilidade dos TestesRESUMO
Drug resistance in Plasmodium falciparum remains a challenge for the malaria eradication programmes around the world. With the emergence of artemisinin resistance, the efficacy of the partner drugs in the artemisinin combination therapies (ACT) that include quinoline-based drugs is becoming critical. So far only few resistance markers have been identified from which only two transmembrane transporters namely PfMDR1 (an ATP-binding cassette transporter) and PfCRT (a drug-metabolite transporter) have been experimentally verified. Another P. falciparum transporter, the ATP-binding cassette containing multidrug resistance-associated protein (PfMRP2) represents an additional possible factor of drug resistance in P. falciparum. In this study, we identified a parasite clone that is derived from the 3D7 P. falciparum strain and shows increased resistance to chloroquine, mefloquine and quinine through the trophozoite and schizont stages. We demonstrate that the resistance phenotype is caused by a 4.1 kb deletion in the 5' upstream region of the pfmrp2 gene that leads to an alteration in the pfmrp2 transcription and thus increased level of PfMRP2 protein. These results also suggest the importance of putative promoter elements in regulation of gene expression during the P. falciparum intra-erythrocytic developmental cycle and the potential of genetic polymorphisms within these regions to underlie drug resistance.
Assuntos
Resistência a Medicamentos/genética , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/genética , Polimorfismo Genético , Regiões Promotoras Genéticas/genética , Proteínas de Protozoários/genética , Quinolinas/farmacologia , Antimaláricos/farmacologia , Pareamento de Bases/genética , Sequência de Bases , Células Clonais , Resistência a Medicamentos/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Genoma de Protozoário/genética , Espaço Intracelular/efeitos dos fármacos , Espaço Intracelular/metabolismo , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Transporte Proteico/efeitos dos fármacos , Proteínas de Protozoários/metabolismo , Análise de Sequência de DNA , Deleção de Sequência/genética , Transcrição Gênica/efeitos dos fármacos , Transcriptoma/genéticaRESUMO
Development of the erythrocytic malaria parasite requires targeting of parasite proteins into multiple compartments located within and beyond the parasite confine. Beyond the PEXEL/VTS pathway and its characterized players, increasing amount of evidence has highlighted the existence of proteins exported using alternative export-signal(s)/pathway(s); hence, the exportomes currently predicted are incomplete. The nature of these exported proteins which could have a prominent role in most of the Plasmodium species remains elusive. Using P. yoelii variant proteins, we identified a signal associated to lipophilic region that mediates export of P. yoelii proteins. This non-PEXEL signal termed PLASMED is defined by semi-conserved residues and possibly a secondary structure. In vivo characterization of exported-proteins indicated that PLASMED is a bona fide export-signal that allowed us to identify an unseen P. yoelii exportome. The repertoire of the newly predicted exported proteins opens up perspectives for unravelling the remodelling of the host-cell by the parasite, against which new therapies could be elaborated.
Assuntos
Plasmodium yoelii/genética , Plasmodium yoelii/metabolismo , Sinais Direcionadores de Proteínas , Proteínas de Protozoários/metabolismo , Sequência de Aminoácidos , Conformação Proteica , Transporte Proteico , Proteínas de Protozoários/química , Proteínas de Protozoários/genéticaRESUMO
Malaria remains a serious public health problem with significant morbidity and mortality accounting for nearly 20% of all childhood deaths in Africa. The cyclical invasion, cytoadherence and destruction of the host's erythrocyte by the parasite are responsible for the observed disease pathology. The invasive form of the parasite, the merozoite, uses a complex set of interactions between parasite ligands and erythrocyte receptors that leads to the formation of a tight junction and ultimately successful erythrocyte invasion. Understanding the molecular mechanism underlying host cell recognition and invasion is crucial for the development of a targeted intervention strategy. Two parasite protein families termed reticulocyte-binding-like protein homologues (RBL) and the erythrocyte-binding-like (EBL) protein family are conserved in all Plasmodium species and have been shown to play an important role in host cell recognition and invasion. Over the last few years significant new insights have been gained in understanding the function of the RBL family and this review attempts to provide an update with a specific focus on the role of RBL in signal transduction pathways during invasion.
Assuntos
Endocitose , Eritrócitos/parasitologia , Plasmodium/patogenicidade , Proteínas de Protozoários/metabolismo , Fatores de Virulência/metabolismo , Modelos Biológicos , Transdução de SinaisRESUMO
BACKGROUND: This study aims to report the clinical characteristics of a child with autosomal recessive polycystic kidney disease (ARPKD) within a Chinese Zhuang ethnic family. METHODS: We used whole exome sequencing (WES) in the family to examine the genetic cause of the disease. Candidate pathogenic variants were validated by Sanger sequencing. RESULTS: We identified previously unreported mutations in the PKHD1 gene of the proband with ARPKD through WES: a splice site mutation c.6809-2Aâ >â T, a nonsense mutation c.4192Câ >â T(p.Gln1398Ter), and a missense mutation c.2181Tâ >â G(p.Asn727Lys). Her mother is a heterozygous carrier of c.2181Tâ >â G(p.Asn727Lys) mutation. Her father is a carrier of c.6809-2Aâ >â T mutation and c.4192Câ >â T(p.Gln1398Ter) mutation. CONCLUSIONS: The identification of novel mutations in the PKHD1 gene through WES not only expands the spectrum of known variants but also potentially enhances genetic counseling and prenatal diagnostic approaches for families affected by ARPKD.
Assuntos
Códon sem Sentido , Linhagem , Rim Policístico Autossômico Recessivo , Receptores de Superfície Celular , Humanos , Rim Policístico Autossômico Recessivo/genética , Receptores de Superfície Celular/genética , Feminino , China , Masculino , Sequenciamento do Exoma , Povo Asiático/genética , Sítios de Splice de RNA/genética , Mutação de Sentido Incorreto , Adulto , População do Leste AsiáticoRESUMO
Introduction: Spodoptera frugiperda is a serious world-wide agricultural pest. Gut microorganisms play crucial roles in growth, development, immunity and behavior of host insects. Methods: Here, we reported the composition of gut microbiota in a laboratory-reared strain of S. frugiperda using 16S rDNA sequencing and the effects of gut microbiota on the reproduction. Results: Proteobacteria and Firmicutes were the predominant bacteria and the taxonomic composition varied during the life cycle. Alpha diversity indices indicated that the eggs had higher bacterial diversity than larvae, pupae and adults. Furthermore, eggs harbored a higher abundance of Ralstonia, Sediminibacterium and microbes of unclassified taxonomy. The dynamics changes in bacterial communities resulted in differences in the metabolic functions of the gut microbiota during development. Interestingly, the laid eggs in antibiotic treatment groups did not hatch much due to the gut dysbacteriosis, the results showed gut microbiota had a significant impact on the male reproduction. Discussion: Our findings provide new perspectives to understand the intricate associations between microbiota and host, and have value for the development of S. frugiperda management strategies focusing on the pest gut microbiota.
RESUMO
BACKGROUND: The association between the total bilirubin/albumin (B/A) and the all-cause mortality of critically ill patients with acute kidney injury (AKI) remains unclear. This retrospective study aimed to investigate the relationship between B/A ratio and mortality in patients with AKI. METHODS: The clinical data of AKI patients in the Medical Information Mart for Intensive Care III (MIMIC-III) database were retrospectively analyzed. Patients were divided into the low and high B/A groups (B/A ≤ 0.25 and B/A > 0.25, respectively). The primary outcome was 28-day all-cause mortality, and the secondary outcomes were 60-day, 1-year and 4-year all-cause mortality. Kaplan-Meier survival curves and Cox proportional risk models were constructed to evaluate the effect of B/A on survival outcomes. RESULTS: The 28-day mortality rates were 18.00% and 25.10% in the low and high B/A groups, respectively (P < 0.001). The Kaplan-Meier analysis showed that patients with higher B/A values had higher all-cause mortality risk (log-rank P < 0.0001). The multivariate Cox proportional risk analysis showed that B/A was an independent risk predictor for death at 28 days, 60 days, 1 year, and 4 years. CONCLUSION: B/A is an independent risk factor for increased mortality in patients with AKI and may be used as a predictor of clinical outcomes in AKI.
Assuntos
Injúria Renal Aguda , Cuidados Críticos , Humanos , Estudos Retrospectivos , Prognóstico , Modelos de Riscos Proporcionais , Injúria Renal Aguda/etiologia , Estado TerminalRESUMO
Object: With the aim of enhancing prevention and regional control of epidemics, the mental health status of medical personnel was analyzed before the implementation of closed-loop management during the COVID-19 pandemic in the regional hospital representative. Methods: In accordance with directives from the unified deployment of the national and regional health bureaus, and following the inclusion and exclusion criteria, from September 2021 to November 2022, all medical personnel assigned to a closed-loop working environment by Guangzhou Panyu Central Hospital were enrolled as research subjects through cluster sampling method. Using a cross-sectional survey method, relevant data such as age, gender, professional title, and mental health status were collected. The Patient Health Questionnaire-9 (PHQ-9) scale, the Generalized Anxiety Disorder-7 (GAD-7) scale, and the Insomnia Severity Index (ISI) scale were administered. Logistic regression analysis was used to study the influencing factors of depression, anxiety, and insomnia. Single factor logistic regression analysis was performed first, followed by multiple factor logistic regression analysis. Results: A total of 500 valid responses were received. Depression was reported by a higher proportion of physicians than nurses. Anxiety was reported by higher proportion of men than women and by a higher proportion of physicians than nurses. Medical personnel under the age of 30 years reported fewer symptoms of insomnia than those over the age of 41 years, and medical personnel with intermediate professional titles reported more severe symptoms of insomnia than junior personnel. There was no significant difference between the results of the three questionnaires for medical personnel from other hospital departments or in the different type of closed-loop work environments. Conclusion: During the pandemic, conducting psychological health assessments for medical personnel undergoing pre-job training in closed-loop management was beneficial for the timely detection of psychological problems. Although this study only conducted a cluster sampling survey and lacked comparative analysis on other medical institutions, it still suggested that it was necessary to strengthen timely psychological counseling and intervention for senior male physicians.
Assuntos
COVID-19 , Distúrbios do Início e da Manutenção do Sono , Humanos , Masculino , Feminino , Adulto , COVID-19/epidemiologia , Pandemias , Distúrbios do Início e da Manutenção do Sono/epidemiologia , Estudos Transversais , Depressão/epidemiologia , Inquéritos e Questionários , Inquéritos EpidemiológicosRESUMO
Plasmodium parasites contribute to one of the highest global infectious disease burdens. To achieve this success, the parasite has evolved a range of specialized subcellular compartments to extensively remodel the host cell for its survival. The information to fully understand these compartments is likely hidden in the so far poorly characterized Plasmodium species spatial proteome. To address this question, we determined the steady-state subcellular location of more than 12,000 parasite proteins across five different species by extensive subcellular fractionation of erythrocytes infected by Plasmodium falciparum, Plasmodium knowlesi, Plasmodium yoelii, Plasmodium berghei, and Plasmodium chabaudi. This comparison of the pan-species spatial proteomes and their expression patterns indicates increasing species-specific proteins associated with the more external compartments, supporting host adaptations and post-transcriptional regulation. The spatial proteome offers comprehensive insight into the different human, simian, and rodent Plasmodium species, establishing a powerful resource for understanding species-specific host adaptation processes in the parasite.
Assuntos
Malária , Proteômica , Humanos , Malária/parasitologia , Proteoma/metabolismo , Plasmodium berghei/metabolismo , Eritrócitos/parasitologiaRESUMO
We aimed to use a genetic risk score (GRS) constructed with prediabetes and type 2 diabetes-related single nucleotide polymorphisms (SNPs) and an oxidative stress score (OSS) to construct an early-prediction model for prediabetes and type 2 diabetes (T2DM) incidence in a Korean population. The study population included 549 prediabetes and T2DM patients and 1036 normal subjects. The GRS was constructed using six prediabetes and T2DM-related SNPs, and the OSS was composed of three recognized oxidative stress biomarkers. Among the nine SNPs, six showed significant associations with the incidence of prediabetes and T2DM. The GRS was profoundly associated with increased prediabetes and T2DM (OR = 1.946) compared with individual SNPs after adjusting for age, sex, and BMI. Each of the three oxidative stress biomarkers was markedly higher in the prediabetes and T2DM group than in the normal group, and the OSS was significantly associated with increased prediabetes and T2DM (OR = 2.270). When BMI was introduced to the model with the OSS and GRS, the area under the ROC curve improved (from 69.3% to 70.5%). We found that the prediction model composed of the OSS, GRS, and BMI showed a significant prediction ability for the incidence of prediabetes and T2DM.
RESUMO
This study aimed to assess the impact of the dietary supplementation of N-carbamoylglutamate (NCG) on nutrient digestibility, rumen fermentation, milk quality, oxidative stress, and metabolites in the plasma and feces of Jersey cattle under high altitude with the hypoxic condition. A total of 14 healthy lactating Jersey dairy cows with similar body conditions were selected and randomly divided into 2 groups. The control group (CON group, N = 6 replicates) was fed with a conventional complete diet, whereas the experimental group (NCG group, N = 8 replicates) received 20 g/d per head NCG supplementation. The experiment lasted for 60 days, the adaptation period was 12 days, and the formal experiment period was 48 days. Except that the NCG group showed an upward trend in dry matter intake (DMI) (p = 0.09) and the fermentation parameters, the molar proportion of butyric acid tended to decrease (p = 0.08); the two groups had no significant differences (p > 0.05) in nutrients digestibility, plasma immunity, and antioxidant ability. However, compared with the CON group, the milk fat rate and blood oxygen saturation of the NCG group showed an upward trend (p = 0.09). For indexes associated with altitude stress, the contents of thyroxine, transferrin, and endothelin both decreased significantly (p < 0.05) in the NCG group. Meanwhile, heat shock protein (p = 0.07) and aldosterone (p = 0.06) also showed a downward trend. A total of 114 different metabolites were identified from feces and plasma, 42 metabolites were derived from plasma that mainly included 5 kinds of Super Class, and 72 metabolites were derived from feces that mainly included 9 kinds of Super Class. The significantly increased plasma differential metabolites were 2,5-dihydroxybenzoate and salicyluric acid, and the significantly increased fecal differential metabolites were Butenafine (fold change > 2). Pathway analysis showed that after applying NCG as a feed additive, the changes of the Jersey dairy cows mainly focused on amino acid metabolism and lipid metabolism. These results indicated that adding NCG to the diet can prevent the hypoxic stress state of lactating Jersey cows in high-altitude areas and has a tendency to improve milk quality.
RESUMO
Heterochromatin-dependent gene silencing is central to the adaptation and survival of Plasmodium falciparum malaria parasites, allowing clonally variant gene expression during blood infection in humans. By assessing genome-wide heterochromatin protein 1 (HP1) occupancy, we present a comprehensive analysis of heterochromatin landscapes across different Plasmodium species, strains, and life cycle stages. Common targets of epigenetic silencing include fast-evolving multi-gene families encoding surface antigens and a small set of conserved HP1-associated genes with regulatory potential. Many P. falciparum heterochromatic genes are marked in a strain-specific manner, increasing the parasite's adaptive capacity. Whereas heterochromatin is strictly maintained during mitotic proliferation of asexual blood stage parasites, substantial heterochromatin reorganization occurs in differentiating gametocytes and appears crucial for the activation of key gametocyte-specific genes and adaptation of erythrocyte remodeling machinery. Collectively, these findings provide a catalog of heterochromatic genes and reveal conserved and specialized features of epigenetic control across the genus Plasmodium.
Assuntos
Proteínas Cromossômicas não Histona/genética , Proteínas Cromossômicas não Histona/metabolismo , Epigênese Genética/genética , Epigenômica , Perfilação da Expressão Gênica , Heterocromatina/genética , Plasmodium/genética , Plasmodium/fisiologia , Adaptação Fisiológica/genética , Adaptação Fisiológica/fisiologia , Animais , Variação Antigênica/genética , Antígenos de Protozoários/genética , Proliferação de Células , Homólogo 5 da Proteína Cromobox , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica , Inativação Gênica , Interações Hospedeiro-Parasita/genética , Interações Hospedeiro-Parasita/fisiologia , Humanos , Estágios do Ciclo de Vida/genética , Estágios do Ciclo de Vida/fisiologia , Malária Falciparum/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Parasitos/genética , Filogenia , Plasmodium/classificação , Plasmodium falciparum/genética , Plasmodium falciparum/metabolismo , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Diferenciação SexualRESUMO
Plasmodium associated virulence in the host is linked to extensive remodelling of the host erythrocyte by parasite proteins that form the "remodellome". However, without a common motif or structure available to identify these proteins, little is known about the proteins that are destined to reside in the parasite periphery, the host-cell cytoplasm and/or the erythrocyte membrane. Here, the subcellular fractionation of erythrocytic P. yoelii at trophozoite and schizont stage along with label-free quantitative LC-MS/MS analysis of the whole proteome, revealed a proteome of 1335 proteins. Differential analysis of the relative abundance of these proteins across the subcellular compartments allowed us to map their locations, independently of their predicted features. These results, along with literature data and in vivo validation of 61 proteins enabled the identification of a remodellome of 184 proteins. This approach identified a significant number of conserved remodelling proteins across plasmodium that likely represent key conserved functions in the parasite and provides new insights into parasite evolution and biology.
Assuntos
Plasmodium yoelii/metabolismo , Proteínas de Protozoários/metabolismo , Animais , Animais Geneticamente Modificados , Evolução Biológica , Eritrócitos/metabolismo , Eritrócitos/parasitologia , Interações Hospedeiro-Parasita , Malária/sangue , Malária/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Plasmodium/genética , Plasmodium/metabolismo , Plasmodium yoelii/genética , Plasmodium yoelii/patogenicidade , Proteoma/metabolismo , Proteômica , Proteínas de Protozoários/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Esquizontes/metabolismo , Frações Subcelulares/metabolismo , Frações Subcelulares/parasitologia , Trofozoítos/metabolismoRESUMO
Infections by malaria parasites can lead to very different clinical outcomes, ranging from mild symptoms to death. Differences in the ability of the spleen to deal with the infected red blood cells (iRBCs) are linked to differences in virulence. Using virulent and avirulent strains of the rodent malaria parasite Plasmodium yoelii, we investigated how parasite virulence modulates overall spleen function. Following parasite invasion, a difference in parasite virulence was observed in association with different levels of spleen morphology and iRBC rigidity, both of which contributed to enhanced parasite clearance. Moreover, iRBC rigidity as modulated by the spleen was demonstrated to correlate with disease outcome and thus can be used as a robust indicator of virulence. The data indicate that alterations in the biomechanical properties of iRBCs are the result of the complex interaction between host and parasite. Furthermore, we confirmed that early spleen responses are a key factor in directing the clinical outcome of an infection. IMPORTANCE The spleen and its response to parasite infection are important in eliminating parasites in malaria. By comparing P. yoelii parasite lines with different disease outcomes in mice that had either intact spleens or had had their spleens removed, we showed that upon parasite infection, the spleen exhibits dramatic changes that can affect parasite clearance. The spleen itself directly impacts RBC deformability independently of parasite genetics. The data indicated that the changes in the biomechanical properties of malaria parasite-infected RBCs are the result of the complex interaction between host and parasite, and RBC deformability itself can serve as a novel predictor of clinical outcome. The results also suggest that early responses in the spleen are a key factor directing the clinical outcome of an infection.
RESUMO
A key step for the survival of the malaria parasite is the release from and subsequent invasion of erythrocytes by the merozoite. Differences in the efficiency of these two linked processes have a direct impact on overall parasite burden in the host and thereby virulence. A number of parasite proteases have recently been shown to play important roles during both merozoite egress as well as merozoite invasion. The rodent malaria parasite Plasmodium yoelii has been extensively used to investigate the mechanisms of parasite virulence in vivo and a number of important proteins have been identified as being key contributors to pathology. Here we have utilized transcriptional comparisons to identify two protease-like SERAs as playing a potential role in virulence. We show that both SERAs are non-essential for blood stage development of the parasite though they provide a subtle but important growth advantage in vivo. In particular SERA2 appears to be an important factor in enabling the parasite to fully utilize the whole age repertoire of circulating erythrocytes. This work for the first time demonstrates the subtle contributions different protease-like SERAs make to provide the parasite with a maximal capacity to successfully maintain an infection in the host.
Assuntos
Antígenos de Protozoários/metabolismo , Eritrócitos/parasitologia , Merozoítos/fisiologia , Plasmodium yoelii/crescimento & desenvolvimento , Animais , Antígenos de Protozoários/genética , Perfilação da Expressão Gênica , Masculino , Merozoítos/crescimento & desenvolvimento , Merozoítos/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Peptídeo Hidrolases/metabolismo , Plasmodium yoelii/genética , Plasmodium yoelii/imunologia , Plasmodium yoelii/patogenicidade , Transporte Proteico , Proteômica , Análise de Sobrevida , Transcrição Gênica , Regulação para CimaRESUMO
Invasion of the erythrocyte by the merozoites of the malaria parasite is a complex process involving a range of receptor-ligand interactions. Two protein families termed Erythrocyte Binding Like (EBL) proteins and Reticulocyte Binding Protein Homologues (RH) play an important role in host cell recognition by the merozoite. In the rodent malaria parasite, Plasmodium yoelii, the 235 kDa rhoptry proteins (Py235) are coded for by a multigene family and are members of the RH. In P. yoelii Py235 as well as a single member of EBL have been shown to be key mediators of virulence enabling the parasite to invade a wider range of host erythrocytes. One member of Py235, PY01365 is most abundantly transcribed in parasite populations and the protein specifically binds to erythrocytes and is recognized by the protective monoclonal antibody 25.77, suggesting a key role of this particular member in virulence. Recent studies have indicated that overall levels of Py235 expression are essential for parasite virulence. Here we show that disruption of PY01365 in the virulent YM line directly impacts parasite virulence. Furthermore the disruption of PY01365 leads to a reduction in the number of schizonts that express members of Py235 that react specifically with the mcAb 25.77. Erythrocyte binding assays show reduced binding of Py235 to red blood cells in the PY01365 knockout parasite as compared to YM. While our results identify PY01365 as a mediator of parasite virulence, they also confirm that other members of Py235 are able to substitute for PY01365.