Activation of nuclear factor kappa B in peripheral blood mononuclear cells from malaria patients

BACKGROUND: Malaria parasites and their products can activate a specific immune response by stimulating cytokine production in the host’s immune cells. Transcription nuclear factor kappa B (NF-κB) is an important regulator for the control of many pro-inflammatory genes, such as interleukin-1 (IL-1) and tumor necrosis factor (TNF). The activation and expression of NF-κB p65 in peripheral blood mononuclear cells (PBMCs) of malaria patients were investigated and correlated with the levels of IL-10 and TNF to study the nature of NF-κB p65 and its linkage to inflammatory cytokines. METHODS: The sample group comprised 33 patients admitted with malaria caused by Plasmodium vivax (n = 11), uncomplicated Plasmodium falciparum (n = 11), and complicated Plasmodium falciparum (n = 11). Peripheral blood was collected at admission and on day 7 for PBMC isolation. Healthy subjects were used as a control group. The expressions of NF-κB p65 in the PBMCs from malaria patients and the plasma levels of IL-10 and TNF were measured by using enzyme-linked immunosorbent assay (ELISA). The immunofluorescence technique was used to determine NF-κB nuclear translocation. RESULTS: At admission, patients with P. vivax and uncomplicated P. falciparum had significantly elevated phospho-NF-κB p65 levels in the PBMCs compared with those of healthy controls. However, patients with complicated P. falciparum malaria had decreased levels of phospho-NF-κB p65. On day 7 post-treatment, significantly increased phospho-NF-κB p65 was found in the PBMCs of patients with complicated P. falciparum, compared with healthy controls. The plasma level of IL-10 was elevated in day 0 in patients with complicated P. falciparum malaria and was found to be negatively correlated with phospho-NF-κB p65 level (r(s) = −0.630, p = 0.038). However, there was no correlation between phospho-NF-κB p65 expression and TNF level in patients with complicated P. falciparum malaria. CONCLUSIONS: This is the first report demonstrating alterations in NF-κB p65 activity in the PBMCs of malaria patients. The altered lower features of NF-κB p65 in the PBMCs of patients with complicated P. falciparum at admission could be due to a suppressive effect of high IL-10 associated with complicated P. falciparum malaria

Erratum for “Effect of aqueous leaf extract of Thunbergia laurifolia on alcohol-induced liver injury in rats”

Purpose: To investigate the antioxidant and anti-inflammatory effects of aqueous leaf extract of T. laurifolia against alcoholic liver injury in rats. Methods: Male Wistar rats were administered either normal saline, ethanol (EtOH), normal saline with low or high dose T. laurifolia leaf extract (TL-LD or TL-HD), EtOH with TL-LD or EtOH with TL-HD. Blood biochemical indices: hepatic malondialdehyde (MDA) levels, liver histopathology, hepatic cytochrome P450 2E1 (CYP2E1), nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, and proinflammatory cytokines, including interleukin 1 beta (IL-1β) and tumor necrotic factor alpha (TNF-α) mRNA expressions, were determined using standard methods. Results: The leaf extract of T. Laurifolia decreased hepatic MDA levels, improved liver pathology and down-regulated mRNA expressions of CYP2E1, NADPH oxidase and pro-inflammatory cytokinesin ethanol-treated rats. Conclusion: These results demonstrate that aqueous extract of T. Laurifolia exerts hepatoprotective effect against alcoholic liver injury through a mechanism involving inhibition of oxidative stress and inflammation

Effect of aqueous leaf extract of Thunbergia laurifolia on alcohol-induced liver injury in rats

Purpose: To investigate the antioxidant and anti-inflammatory effects of aqueous leaf extract of T. laurifolia against alcoholic liver injury in rats. Methods: Male Wistar rats were administered either normal saline, ethanol (EtOH), normal saline with low or high dose T. laurifolia leaf extract (TL-LD or TL-HD), EtOH with TL-LD or EtOH with TL-HD. Blood biochemical indices: hepatic malondialdehyde (MDA) levels, liver histopathology, hepatic cytochrome P450 2E1 (CYP2E1), nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, and pro-inflammatory cytokines, including interleukin 1 beta (IL-1β) and tumor necrotic factor alpha (TNF-α) mRNA expressions, were determined using standard methods. Results: The leaf extract of T. Laurifolia decreased hepatic MDA levels, improved liver pathology and down-regulated mRNA expressions of CYP2E1, NADPH oxidase and pro-inflammatory cytokinesin ethanol-treated rats. Conclusion: These results demonstrate that aqueous extract of T. Laurifolia exerts hepatoprotective effect against alcoholic liver injury through a mechanism involving inhibition of oxidative stress and inflammation

Effect of a heme oxygenase-1 inducer on NADPH oxidase expression in alcohol-induced liver injury in male Wistar rats

Purpose: To investigated the effect of hemin, a heme oxygenase-1 (HO-1) inducer, on nicotinamide adenine dinucleotide phosphate oxidase (NOX) expression in rats with alcohol-induced liver injury.Methods: Male Wistar rats were randomly divided into four groups consisting of the control group, the ethanol (EtOH) group, the EtOH + zinc protoporphyrin IX (ZnPP-IX) group and EtOH + hemin group. Hepatic NOX gene expression and immunohistochemistry of hepatic NOX1 and NOX4 were investigated in week 4.Results: EtOH significantly increased levels of NOX. An immunohistochemical study demonstrated a high number of immunopositive hepatocytes for NOX1 in the EtOH group and EtOH + ZnPP-IX group compared with the control group. Hemin administration downregulated NOX gene expression and lowered the number of immunopositive hepatocytes for NOX1. In contrast, ZnPP-IX (HO-1 inhibitor) administration caused upregulation of NOX gene expression and increased the number of immunopositive hepatocytes for NOX1.Conclusion: HO-1 inducer, hemin, alleviates oxidative stress-induced alcoholic liver injury by reducing NOX, especially NOX1.Keywords: NADPH oxidase, Immunohistochemistry, Heme oxygenase-1, Hemin, Reactive oxygen species, Alcohol-induced liver diseas

Nuclear factor kappa B in urine sediment: a useful indicator to detect acute kidney injury in Plasmodium falciparum malaria

BACKGROUND: Acute kidney injury (AKI) is one of the major complications of Plasmodium falciparum malaria, especially among non-immune adults. It has recently been revealed that activation of transcription factor nuclear factor kappa B (NF-κB) induces pro-inflammatory gene expression involved in the development of progressive renal inflammatory diseases. The aim of this study was to determine whether urinary sediment NF-κB p65 can act as a biomarker for AKI in patients with P. falciparum malaria. METHODS: Urinary sediments from malaria patients, including Plasmodium vivax malaria, uncomplicated P. falciparum malaria, complicated P. falciparum malaria without AKI (serum creatinine-Cr <3 mg/dl) and complicated P. falciparum malaria with AKI (Cr ≥3 mg/dl) were used to determine NF-κB p65 level by sandwich enzyme-linked immunosorbent assay (ELISA). Urinary sediments obtained from healthy controls were used as a normal baseline. Correlations between levels of urinary sediment NF-κB p65 and pertinent clinical data were analysed. RESULTS: Urinary sediment NF-κB p65 levels were significantly increased on the day of admission (day 0) and on day 7 post-treatment in complicated P. falciparum malaria patients with AKI, compared with those without AKI (p = 0.001, p <0.001, respectively), P. vivax patients (all p <0.001) and healthy controls (all p <0.001). NF-κB p65 levels in urinary sediment cells showed a significant positive correlation with serum Cr (Day 0: r(s) = 0.792; p <0.001, Day 7: r(s) = 0.605; p <0.001) and blood urea nitrogen (BUN) (Day 0: r(s) = 0.839; p <0.001, Day 7: r(s) = 0.596; p <0.001). CONCLUSIONS: Urinary sediment NF-κB p65 level is a useful indicator for estimating renal tubular epithelial cell damage and subsequent development of AKI among patients with P. falciparum malaria

Nuclear factor kappa B modulates apoptosis in the brain endothelial cells and intravascular leukocytes of fatal cerebral malaria

Abstract Background Cerebral malaria (CM) caused by Plasmodium falciparum is known to be associated with the sequestration of parasitized red blood cells (PRBCs) in the microvasculature and the release of soluble cytokines. In addition, the involvement of signaling molecules has gained wide interest in the pathogenesis of CM. An important signaling factor, nuclear factor kappa B (NF-κB) is known to regulate apoptosis. This work aimed to study the expression of NF-κB p65 and its correlation with apoptosis in the brain of fatal CM. Methods The expression of NF-κB p65 and cleaved caspase-3 in the brain of fatal P. falciparum malaria cases was investigated by immunohistochemistry. Histopathological features were analysed together with the correlations of NF-κB p65 and cleaved caspase-3 expression. Results NF-κB p65 activation and cleaved caspase-3 expression were significantly increased in the neurons, glial cells, vascular endothelial cells (ECs) and intravascular leukocytes of the brain in fatal CM, compared with the control brain (p &lt; 0.001) and non-cerebral malaria (NCM) (p = 0.034). The percentage of neurons that expressed nuclear NF-κB p65 showed a positive correlation with the total score of histopathological changes (r s = 0.678; p = 0.045). Significant positive correlations were established between vascular ECs NF-κB index and ECs apoptotic index (r s = 0.717; p = 0.030) and between intravascular leukocytes NF-κB index and leukocytes apoptotic index (r s = 0.696; p = 0.037) in fatal CM. Conclusions This study documented that NF-κB p65 is one of the signaling factors that modulates apoptosis in the brain ECs and intravascular leukocytes of fatal CM. </jats:sec

Immunofluorescence study of cytoskeleton in endothelial cells induced with malaria sera

Background: Endothelial cells (ECs) play a major role in malaria pathogenesis, as a point of direct contact of parasitized red blood cells to the blood vessel wall. The study of cytoskeleton structures of ECs, whose main functions are to maintain shape and provide strength to the EC membrane is important in determining the severe sequelae of Plasmodium falciparum malaria. The work investigated the cytoskeletal changes (microfilaments-actin, microtubules-tubulin and intermediate filaments-vimentin) in ECs induced by malaria sera (Plasmodium vivax, uncomplicated P. falciparum and complicated P. falciparum), in relation to the levels of pro-inflammatory cytokines. Methods: Morphology and fluorescence intensity of EC cytoskeleton stimulated with malaria sera were evaluated using immunofluorescence technique. Levels of tumour necrosis factor (TNF) and interferon (IFN)-gamma (γ) were determined using enzyme-linked immunosorbent assay (ELISA). Control experimental groups included ECs incubated with media alone and non-malaria patient sera. Experimental groups consisted of ECs incubated with malaria sera from P. vivax, uncomplicated P. falciparum and complicated P. falciparum. Morphological scores of cytoskeletal alterations and fluorescence intensity were compared across each experiment group, and correlated with TNF and IFN-γ. Results: The four morphological changes of cytoskeleton included (1) shrinkage of cytoskeleton and ECs with cortical condensation, (2) appearance of eccentric nuclei, (3) presence of “spiking pattern” of cytoskeleton and EC membrane, and (4) fragmentation and discontinuity of cytoskeleton and ECs. Significant damages were noted in actin filaments compared to tubulin and vimentin filaments in ECs stimulated with sera from complicated P. falciparum malaria. Morphological damages to cytoskeleton was positively correlated with fluorescence intensity and the levels of TNF and IFN-γ. Conclusions: ECs stimulated with sera from complicated P. falciparum malaria showed cytoskeletal alterations and increased in fluorescence intensity, which was associated with high levels of TNF and IFN-γ. Cytoskeletal changes of ECs incubated with complicated P. falciparum malaria sera can lead to EC junctional alteration and permeability changes, which is mediated through apoptotic pathway. The findings can serve as a basis to explore measures to strengthen EC cytoskeleton and alleviate severe malaria complications such as pulmonary oedema and cerebral malaria. In addition, immunofluorescence intensity of cytoskeleton could be investigated as potential prognostic indicator for malaria severity

Study of pulsatile pressure-driven electroosmotic flows through an elliptic cylindrical microchannel with the Navier slip condition

This paper aims to study an unsteady electric field-driven and pulsatile pressure-driven flow of a Newtonian fluid in an elliptic cylindrical microchannel with Navier boundary wall slip. The governing equations of the slip flow and distributions of electric potential and charge densities are the modified Navier-Stokes equations, the Poisson equation and the Nernst-Planck equations, respectively. Analytical and numerical analyses based on the Mathieu and modified Mathieu equations are performed to investigate the interplaying effects of pulsatile pressure gradients and the slip lengths on the electroosmotic flow