scholarly journals Molecular Factors and Biochemical Pathways Induced by Febrile Temperature in Intraerythrocytic Plasmodium falciparum Parasites

2007 ◽  
Vol 75 (4) ◽  
pp. 2012-2025 ◽  
Author(s):  
Miranda S. M. Oakley ◽  
Sanjai Kumar ◽  
Vivek Anantharaman ◽  
Hong Zheng ◽  
Babita Mahajan ◽  
...  

ABSTRACT Intermittent episodes of febrile illness are the most benign and recognized symptom of infection with malaria parasites, although the effects on parasite survival and virulence remain unclear. In this study, we identified the molecular factors altered in response to febrile temperature by measuring differential expression levels of individual genes using high-density oligonucleotide microarray technology and by performing biological assays in asexual-stage Plasmodium falciparum parasite cultures incubated at 37°C and 41°C (an elevated temperature that is equivalent to malaria-induced febrile illness in the host). Elevated temperature had a profound influence on expression of individual genes; 336 of approximately 5,300 genes (6.3% of the genome) had altered expression profiles. Of these, 163 genes (49%) were upregulated by twofold or greater, and 173 genes (51%) were downregulated by twofold or greater. In-depth sensitive sequence profile analysis revealed that febrile temperature-induced responses caused significant alterations in the major parasite biologic networks and pathways and that these changes are well coordinated and intricately linked. One of the most notable transcriptional changes occurs in genes encoding proteins containing the predicted Pexel motifs that are exported into the host cytoplasm or inserted into the host cell membrane and are likely to be associated with erythrocyte remodeling and parasite sequestration functions. Using our sensitive computational analysis, we were also able to assign biochemical or biologic functional predictions for at least 100 distinct genes previously annotated as “hypothetical.” We find that cultivation of P. falciparum parasites at 41°C leads to parasite death in a time-dependent manner. The presence of the “crisis forms” and the terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling-positive parasites following heat treatment strongly support the notion that an apoptosis-like cell death mechanism might be induced in response to febrile temperatures. These studies enhance the possibility of designing vaccines and drugs on the basis of disruption in molecules and pathways of parasite survival and virulence activated in response to febrile temperatures.

2014 ◽  
Vol 84 (3-4) ◽  
pp. 0183-0195 ◽  
Author(s):  
Takashi Nakamura ◽  
Tomoya Takeda ◽  
Yoshihiko Tokuji

The common water-soluble organic germanium compound poly-trans-[(2-carboxyethyl) germasesquioxane] (Ge-132) exhibits activities related to immune responses and antioxidant induction. In this study, we evaluated the antioxidative effect of dietary Ge-132 in the plasma of mice. Male ICR mice (seven mice per group) received an AIN-76 diet with 0.05 % Ge-132; three groups received the Ge-132-containing diet for 0, 1 or 4 days. The plasma alpha-tocopherol (α-tocopherol) concentration increased from 6.85 to 9.60 μg/ml after 4 days of Ge-132 intake (p < 0.05). We evaluated the changes in hepatic gene expression related to antioxidative activity as well as in the entire expression profile after one day of Ge-132 intake, using DNA microarray technology. We identified 1,220 genes with altered expression levels greater than 1.5-fold (increased or decreased) as a result of Ge-132 intake, and α-tocopherol transfer protein (Ttpa) gene expression was increased 1.62-fold. Immune activation was identified as the category with the most changes (containing 60 Gene Ontology (GO) term biological processes (BPs), 41 genes) via functional clustering analysis of altered gene expression. Ge-132 affected genes in clusters related to ATP production (22 GO term BPs, 21 genes), lipid metabolism (4 GO term BPs, 38 genes) and apoptosis (5 GO term BPs). Many GO term BPs containing these categories were significantly affected by the Ge-132 intake. Oral Ge-132 intake may therefore have increased plasma α-tocopherol levels by up-regulating α-tocopherol transfer protein (Ttpa) gene expression.


Author(s):  
MA Parker ◽  
E Nell ◽  
A Mowlana ◽  
MS Moolla ◽  
S Karamchand ◽  
...  

Background: More than 90% of the global 400 000 annual malaria deaths occur in Africa. The current SARS-CoV-2 pandemic has resulted in more than 830 000 deaths in its first 10 months. Case presentation: This case describes a patient who had travelled from Mozambique to Cape Town, presented with a mild febrile illness, and was diagnosed with both COVID-19 and uncomplicated Plasmodium falciparum malaria infection. She responded well to malaria treatment and had an uneventful COVID-19 admission. Her blood smear showed a low malaria parasitaemia and a relatively high gametocyte load. Conclusion: We postulate that her clinical course and abnormal smear could well be due to reciprocal disease-modifying effects of the infections. The presenting symptoms of COVID-19 may mimic endemic infectious diseases including malaria, tuberculosis, pneumocystis pneumonia and influenza thus there is a need for clinical vigilance to identify and treat such co-infections.


Author(s):  
Han-Wen Chen ◽  
Xiao-Xia Zhang ◽  
Zhu-Ding Peng ◽  
Zu-Min Xing ◽  
Yi-Wen Zhang ◽  
...  

AbstractTreatment of bone cancer pain (BCP) caused by bone metastasis in advanced cancers remains a challenge in clinical oncology, and the underlying mechanisms of BCP are poorly understood. This study aimed to investigate the pathogenic roles of circular RNAs (circRNAs) in regulating cancer cell proliferation and BCP development. Eight differentially expressed circRNAs in the rat spinal cord were validated by agarose gel electrophoresis and Sanger sequencing. Expression of circRNAs and mRNAs was detected by quantitative RT-PCR. MTS assay and flow cytometry were performed to analyze cell proliferation and apoptosis, respectively. Differentially expressed mRNA profiles were characterized by deep RNA sequencing, hierarchical clustering, and functional categorization. The interactions among circRNAs, microRNAs (miRNAs), and mRNAs were predicted using TargetScan. Additionally, western blot was performed to determine the protein levels of Pax8, Isg15, and Cxcl10. Multiple circRNAs were differentially expressed in the spinal cords of BCP model rats; of these, circSlc7a11 showed the greatest increase in expression. The overexpression of circSlc7a11 significantly promoted cell proliferation and repressed apoptosis of LLC-WRC 256 and UMR-106 cells, whereas circSlc7a11 silencing produced the opposite effects. Altered expression of circSlc7a11 also induced substantial changes in the mRNA expression profiles of LLC-WRC 256 cells; these changes were linked to multiple apoptotic processes and signaling pathways, such as the chemokine signaling pathway, and formed a complex circRNA/miRNA/mRNA network. Additionally, Pax8, Isg15, and Cxc110 protein level in LLC-WRC 256 cells was consistent with the mRNA results. The circRNA circSlc7a11 regulates rat BCP development by modulating LLC-WRC 256 cell proliferation and apoptosis through multiple-signaling mechanisms.


Dose-Response ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 155932582110198
Author(s):  
Mohammed S. Aldughaim ◽  
Mashael R. Al-Anazi ◽  
Marie Fe F. Bohol ◽  
Dilek Colak ◽  
Hani Alothaid ◽  
...  

Cadmium telluride quantum dots (CdTe-QDs) are acquiring great interest in terms of their applications in biomedical sciences. Despite earlier sporadic studies on possible oncogenic roles and anticancer properties of CdTe-QDs, there is limited information regarding the oncogenic potential of CdTe-QDs in cancer progression. Here, we investigated the oncogenic effects of CdTe-QDs on the gene expression profiles of Chang cancer cells. Chang cancer cells were treated with 2 different doses of CdTe-QDs (10 and 25 μg/ml) at different time intervals (6, 12, and 24 h). Functional annotations helped identify the gene expression profile in terms of its biological process, canonical pathways, and gene interaction networks activated. It was found that the gene expression profiles varied in a time and dose-dependent manner. Validation of transcriptional changes of several genes through quantitative PCR showed that several genes upregulated by CdTe-QD exposure were somewhat linked with oncogenesis. CdTe-QD-triggered functional pathways that appear to associate with gene expression, cell proliferation, migration, adhesion, cell-cycle progression, signal transduction, and metabolism. Overall, CdTe-QD exposure led to changes in the gene expression profiles of the Chang cancer cells, highlighting that this nanoparticle can further drive oncogenesis and cancer progression, a finding that indicates the merit of immediate in vivo investigation.


Author(s):  
Pooja Khurana ◽  
Neil R. Smyth ◽  
Bhavwanti Sheth ◽  
Miguel A. Velazquez ◽  
Judith J. Eckert ◽  
...  

Abstract Advanced maternal age (AMA) is known to reduce fertility, increases aneuploidy in oocytes and early embryos and leads to adverse developmental consequences which may associate with offspring lifetime health risks. However, investigating underlying effects of AMA on embryo developmental potential is confounded by the inherent senescence present in maternal body systems further affecting reproductive success. Here, we describe a new model for the analysis of early developmental mechanisms underlying AMA by the derivation and characterisation of mouse embryonic stem cell (mESC-like) lines from naturally conceived embryos. Young (7–8 weeks) and Old (7–8 months) C57BL/6 female mice were mated with young males. Preimplantation embryos from Old dams displayed developmental retardation in blastocyst morphogenesis. mESC lines established from these blastocysts using conventional techniques revealed differences in genetic, cellular and molecular criteria conserved over several passages in the standardised medium. mESCs from embryos from AMA dams displayed increased incidence of aneuploidy following Giemsa karyotyping compared with those from Young dams. Moreover, AMA caused an altered pattern of expression of pluripotency markers (Sox2, OCT4) in mESCs. AMA further diminished mESC survival and proliferation and reduced the expression of cell proliferation marker, Ki-67. These changes coincided with altered expression of the epigenetic marker, Dnmt3a and other developmental regulators in a sex-dependent manner. Collectively, our data demonstrate the feasibility to utilise mESCs to reveal developmental mechanisms underlying AMA in the absence of maternal senescence and with reduced animal use.


2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Zhigang Zhang ◽  
Tianshu Zhai ◽  
Mingshuo Li ◽  
Kun Zhang ◽  
Jingrui Li ◽  
...  

AbstractNeutralizing antibodies (NAbs) have attracted attention as tools for achieving PRRSV control and prevention, but viral antigenic variation undermines the abilities of NAbs elicited by attenuated PRRSV vaccines to confer full protection against heterogeneous PRRSV field isolates. As demonstrated in this study, the monoclonal antibody (mAb) mAb-PN9cx3 exhibited broad-spectrum recognition and neutralizing activities against PRRSV-1 and PRRSV-2 strains in vitro. Furthermore, in vivo experiments revealed that the administration of two 10-mg doses of mAb-PN9cx3 before and after the inoculation of piglets with heterologous PRRSV isolates (HP-PRRSV-JXA1 or PRRSV NADC30-like strain HNhx) resulted in significant reduction of the PRRSV-induced pulmonary pathological changes and virus loads in porcine alveolar macrophages (PAMs) compared with the results obtained with mAb-treated isotype controls. Moreover, minimal hilar lymph node PRRSV antigen levels were observed in mAb-PN9cx3-treated piglets. A transcriptome profile analysis of PAMs extracted from lung tissues of piglets belonging to different groups (except for antibody-isotype controls) indicated that mAb-PN9cx3 treatment reversed the PRRSV infection-induced alterations in expression profiles. A gene ontology (GO) enrichment analysis of these genes traced their functions to pathways that included the immune response, inflammatory response, and response to steroid hormone, and their functions in oogenesis and positive regulation of angiogenesis have been implicated in PRRSV pathogenesis. Overall, NADC30-like HNhx infection affected more gene pathways than HP-PRRSV infection. In conclusion, our research describes a novel immunologic approach involving the use of mAbs that confer cross-protection against serious illness resulting from infection with heterogeneous PRRSV-2 isolates, which is a feat that has not yet been achieved through vaccination. Ultimately, mAb-PN9cx3 will be a powerful addition to our current arsenal for achieving PRRSV prevention and eradication.


2021 ◽  
Vol 42 (2) ◽  
pp. 242-250
Author(s):  
S.I. Oyedeji ◽  
I.M. Odoh ◽  
A.O. Ojerinde ◽  
H.O. Awobode

The gold standard for malaria diagnosis is evidence of parasitological confirmation but the traditional method by light microscopy and the routinely used rapid diagnostic tests (RDTs) have limitations. Molecular assays are known to have higher sensitivity and specificity but there are indications that they may also be compromised by genetic variability of the target sequence. The aim of this study therefore, was to evaluate the DNA sequence profile of the diagnostic target of the P. falciparum 18S rRNA PCR assay in field isolates from North-Central Nigeria. Blood samples were collected from 324 children presenting with acute febrile illness suspected to be uncomplicated malaria. Light microscopy and 18S rRNA PCR assay were employed to determine the presence of P. falciparum parasites. Sequence profile of the diagnostic target was evaluated by Sanger sequencing of the PCR products on ABI PRISM® 3100 DNA sequencer (PE Applied Biosystems). Of the 324 children enrolled into this study, 134 (41.4%) were positive for P. falciparum by microscopy while 218 (67.3%) were positive by PCR. The sensitivity of microscopy was 61.47%(95% CI= 57.88% - 69.64%) using the PCR assay as reference standard. The degree of agreement between microscopy and PCR as measured by Cohen's kappa was  moderate (κ = 0.502, 95% CI = 0.463 - 0.715).Sequence analysis showed that the DNA target of the P. falciparum 18S rRNA PCR from the field isolates were highly conserved. Only one A>T single nucleotide polymorphism was found within the target sequence  among the isolates in this study. This study showed that the DNA target sequence of the18S rRNA PCR assay is highly conserved in field isolates in the study region suggesting little or no impact of selective pressure acting on the locus and has implications for the enhanced sensitivity of the molecular assay.


2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Carolina Salazar-Ruales ◽  
Jessica-Viviana Arguello ◽  
Andrés López-Cortés ◽  
Alejandro Cabrera-Andrade ◽  
Jennyfer M. García-Cárdenas ◽  
...  

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer with the highest incidence worldwide. HNSCC is often diagnosed at advanced stages, incurring significant high mortality and morbidity. The use of saliva, as a noninvasive tool for the diagnosis of cancer, has recently increased. Salivary microRNAs (miRNAs) have emerged as a promising molecular tool for early diagnosis of HNSCC. The aim was to identify the differential expression of salivary miRNAs associated with HNSCC in the high altitude mestizo Ecuadorian population. Using PCR Arrays, miR-122-5p, miR-92a-3p, miR-124-3p, miR-205-5p, and miR-146a-5p were found as the most representative ones. Subsequently, miRNAs expression was confirmed in saliva samples from 108 cases and 108 controls. miR-122-5p, miR-92a-3p, miR-124-3p, and miR-146a-5p showed significant statistical difference between cases and controls with areas under the curve (AUC) of 0.73 (p < 0.001), 0.70 (p < 0.001), 0.71 (p = 0.002), and 0.66 (p = 0.008), respectively. miRNAs were also deregulated in between HNSCC localizations. A differentiated expression of miR-122-5p between oral cancer and oropharynx cancer (AUC of 0.96 p = 0.01) was found: miR-124-3p between larynx and pharynx (AUC = 0.97, p < 0.01) and miR-146a-5p between larynx, oropharynx, and oral cavity (AUC = 0.96, p = 0.01). Moreover, miR-122-5p, miR-124-3p, miR-205-5p, and miR-146a-5p could differentiate between HPV+ and HPV- (p=0.004). Finally, the expression profiles of the five miRNAs were evaluated to discriminate HNSCC patient’s tumor stages (TNM 2-4). miR-122-5p differentiates TNM 2 and 3 (p = 0.002, AUC = 0.92), miR-124-3p TNM 2, 3, and 4 (p < 0.001, AUC = 98), miR-146a-5p TNM 2 and 3 (p < 0.001, AUC = 0.97), and miR-92a-3p TNM 3 (p < 0.001, AUC = 0.99). Taken together, these findings show that altered expression of miRNAs could be used as biomarkers for HNSCC diagnosis in the high altitude mestizo Ecuadorian population.


2011 ◽  
Vol 2011 ◽  
pp. 1-21 ◽  
Author(s):  
Elizabeth G. Kane ◽  
Andrew W. Taylor-Robinson

Pregnancy-associated malaria, a manifestation of severe malaria, is the cause of up to 200,000 infant deaths a year, through the effects of placental insufficiency leading to growth restriction and preterm delivery. Development of a vaccine is one strategy for control. Plasmodium falciparum-infected red blood cells accumulate in the placenta through specific binding of pregnancy-associated parasite variants that express the VAR2CSA antigen to chondroitin sulphate A on the surface of syncytiotrophoblast cells. Parasite accumulation, accompanied by an inflammatory infiltrate, disrupts the cytokine balance of pregnancy with the potential to cause placental damage and compromise foetal growth. Multigravid women develop immunity towards VAR2CSA-expressing parasites in a gravidity-dependent manner which prevents unfavourable pregnancy outcomes. Although current vaccine design, targeting VAR2CSA antigens, has succeeded in inducing antibodies artificially, this candidate may not provide protection during the first trimester and may only protect those women living in areas endemic for malaria. It is concluded that while insufficient information about placental-parasite interactions is presently available to produce an effective vaccine, incremental progress is being made towards achieving this goal.


2013 ◽  
Vol 9 (2) ◽  
pp. 41 ◽  
Author(s):  
Seung-Hwa Jeong ◽  
Hyung-Jin Lee ◽  
Jin-Seok Yi ◽  
Hong-Jae Lee ◽  
Il-Woo Lee ◽  
...  

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