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1.
BMC Mol Cell Biol ; 25(1): 4, 2024 Feb 10.
Article in English | MEDLINE | ID: mdl-38336617

ABSTRACT

BACKGROUND: The lack of appropriate prognostic biomarkers remains a significant obstacle in the early detection of Head and Neck Squamous Cell Carcinoma (HNSCC), a cancer type with a high mortality rate. Despite considerable advancements in treatment, the success in diagnosing HNSCC at an early stage still needs to be improved. Nuclear factor erythroid 2-related factor 2 (Nrf2) and Sonic Hedgehog (Shh) are overexpressed in various cancers, including HNSCC, and have recently been proposed as possible therapeutic targets for HNSCC. Circulating Tumor Cell (CTC) is a novel concept used for the early detection of cancers, and studies have suggested that a higher CTC count is associated with the aggressiveness of HNSCC and poor survival rates. Therefore, we aimed to establish molecular markers for the early diagnosis of HNSCC considering Shh/Nrf2 overexpression in the background. In addition, the relation between Shh/Nrf2 and CTCs is still unexplored in HNSCC patients. METHODS: In the present study, we selected a cohort of 151 HNSCC patients and categorized them as CTC positive or negative based on the presence or absence of CTCs in their peripheral blood. Data on demographic and clinicopathological features with the survival of the patients were analyzed to select the patient cohort to study Shh/Nrf2 expression. Shh and Nrf2 expression was measured by qRT-PCR. RESULTS: Considering significant demographic [smoking, betel leaf (p-value < 0.0001)] and clinicopathological risk factors [RBC count (p < 0.05), Platelet count (p < 0.05), Neutrophil count (p < 0.005), MCV (p < 0.0001), NLR (p < 0.05), MLR (p < 0.05)], patients who tested positive for CTC also exhibited significant overexpression of Shh/Nrf2 in both blood and tissue compared to CTC-negative patients. A strong association exists between CTCs and tumor grade. Following chemotherapy (a combination of Cisplatin, 5FU, and Paclitaxel), the frequency of CTCs was significantly decreased in patients with HNSCC who had tested positive for CTCs. The Kaplan-Meier plot illustrated that a higher number of CTCs is associated with poorer overall survival (OS) in patients with HNSCC. CONCLUSIONS: Detecting CTCs, and higher expression of Shh and Nrf2 in HNSCC patients' blood, can be a promising tool for diagnosing and prognosticating HNSCC.


Subject(s)
Head and Neck Neoplasms , NF-E2-Related Factor 2 , Humans , Squamous Cell Carcinoma of Head and Neck/diagnosis , Squamous Cell Carcinoma of Head and Neck/genetics , Prospective Studies , Hedgehog Proteins , Head and Neck Neoplasms/diagnosis , Head and Neck Neoplasms/genetics
2.
Exp Hematol ; 118: 53-64.e1, 2023 02.
Article in English | MEDLINE | ID: mdl-36574579

ABSTRACT

The manifestation of coronavirus disease 2019 (COVID-19) severity and mortality has been associated with dysregulation of the immune response, often influenced by racial disparities and conferred by changes in hematologic and immunologic parameters. These biological and hematologic parameters as well as cytokine profiles were investigated in a cohort of 61 COVID-19-positive patients (categorized into mild, moderate, and severe groups) from Bangladesh using standard analytical methods. The data reported that the interleukin (IL)-4 and IL-6 levels were significantly increased, whereas the levels of interferon (IFN)-γ were significantly reduced in patients with severe COVID-19 (p < 0.05) compared with those in patients with mild and/or moderate COVID-19. The extent of erythrocyte sedimentation rate (ESR); neutrophil count; and levels of ferritin, C-reactive protein (CRP), and D-dimer (p < 0.05) were found to be significantly increased, whereas the white blood cell (WBC), lymphocyte, eosinophil, and platelet counts (p < 0.05) were observed to be significantly reduced in patients with severe COVID-19 compared with those in the patients in other 2 groups. Our study exhibited a significantly higher IL-6-to-lymphocyte ratio in patients with severe COVID-19 than in those with mild and moderate COVID-19. The calculated neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), and ferritin-to-ESR ratio were significantly increased in patients with severe COVID-19. The increase in the IL-4 and IL-6 levels along with CRP and D-dimer levels may envisage a hyperinflammatory environment and immune dysregulation, which contribute to prolonged viral persistence, leading to severe disease. However, the reduced level of IFN-γ can be attributed to a less fatality toll in Bangladesh compared with that in the rest of the world.


Subject(s)
COVID-19 , Humans , Interleukin-6 , Lymphocytes , Leukocyte Count , C-Reactive Protein/analysis , Neutrophils , Interferon-gamma , Retrospective Studies
3.
JNCI Cancer Spectr ; 4(1): pkz063, 2020 Feb.
Article in English | MEDLINE | ID: mdl-32296756

ABSTRACT

BACKGROUND: Triple-negative breast cancer (TNBC) is characterized by poor prognosis and lack of targeted therapies and biomarkers to guide decisions on adjuvant chemotherapy. Parathyroid hormone-related protein (PTHrP) is frequently overexpressed in breast cancer and involved in proliferation and metastasis, two hallmarks of poor prognosis for node-negative breast cancer. We investigated the prognostic value of PTHrP with respect to organ-specific metastasis and nodal status in TNBC. METHODS: We assessed PTHrP expression using immunohistochemistry in a clinically annotated tissue microarray for a population-based study of 314 patients newly diagnosed with TNBC, then analyzed its correlation to progression and survival using Kaplan-Meier and Cox regression analyses. The Cancer Genome Atlas (TCGA) validation analysis was performed through Bioconductor. All statistical tests were two-sided. RESULTS: PTHrP overexpression (160 of 290 scorable cases, 55.2%) was statistically significantly associated in univariate analysis with decreased overall survival (OS) in our cohort (P = .0055) and The Cancer Genome Atlas (P = .0018) and decreased central nervous system (CNS)-progression-free survival (P = .0029). In multivariate analysis, PTHrP was a statistically significant independent prognostic factor for CNS-progression-free survival in TNBC (hazard ratio [HR] = 5.014, 95% confidence interval [CI] = 1.421 to 17.692, P = .0122) and for OS selectively in node-negative TNBC (HR = 2.423, 95% CI = 1.129 to 5.197, P = .0231). Strikingly, PTHrP emerged as the only statistically significant prognostic factor (HR = 2.576, 95% CI = 1.019 to 6.513, P = .0456) for OS of low-clinical risk node-negative patients who did not receive adjuvant chemotherapy. CONCLUSIONS: PTHrP is a novel independent prognostic factor for CNS metastasis and adjuvant chemotherapy selection of low-clinical risk node-negative TNBC. Its predictive value needs to be prospectively assessed in clinical trials.

4.
Chemosphere ; 120: 336-42, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25180936

ABSTRACT

Arsenic exposure is associated with cancer and vascular diseases. Angiogenesis is an important step for the pathological development of cancer and vascular diseases. Vascular endothelial growth factor (VEGF) is a specific marker for angiogenesis. However, human study showing the association between arsenic exposure and serum VEGF levels has not yet been documented. This study was aimed to investigate the association between arsenic exposure and serum VEGF levels in the arsenic-endemic individuals in Bangladesh. A total of 260 individuals were recruited for this study. Arsenic exposure levels were measured by ICP-MS and VEGF levels were quantified using VEGF immunoassay kit. The study subjects were stratified into tertile (low, medium and high) groups based on the arsenic in water, hair and nails. Serum VEGF levels were correlated with water (rs = 0.363, p < 0.001), hair (rs = 0.205, p < 0.01) and nail (rs = 0.190, p < 0.01) arsenic. Further, VEGF levels showed dose-response relationships with water, hair and nail arsenic. Mean VEGF levels in ⩽ 10 µg L(-1), 10.1-50 µg L(-1) and > 50 µg L(-1) groups were 91.84, 129.54, and 169.86 pg mL(-1), respectively, however, significant (p < 0.01) difference in VEGF levels was only found in > 50 µg L(-1) versus ⩽ 10 µg L(-1) groups. Significant associations of arsenic exposure with VEGF levels were found even after adjusting with relevant covariates. Therefore, these results provide evidence that arsenic exposure has a pro-angiogenic effect on humans, which may be implicated in arsenic-induced tumorigenesis and vascular diseases.


Subject(s)
Arsenic/analysis , Drinking Water/analysis , Vascular Endothelial Growth Factor A/metabolism , Water Pollutants, Chemical/analysis , Adolescent , Adult , Arsenic/metabolism , Bangladesh , Female , Hair/chemistry , Humans , Male , Middle Aged , Nails/chemistry , Water Pollutants, Chemical/metabolism , Young Adult
5.
J Cytol Histol ; 6(3)2015 May.
Article in English | MEDLINE | ID: mdl-26740907

ABSTRACT

Deposition of arsenic in mice through groundwater is well documented but little is known about the histological changes of organs by the metalloid. Present study was designed to evaluate arsenic-induced histological alterations in kidney, liver, thoracic artery and brain of mice which are not well documented yet. Swiss albino male mice were divided into 2 groups and treated as follows: Group 1: control, 2: arsenic (sodium arsenite at 10 mg/kg b.w. orally for 8 wks). Group 2 showed marked degenerative changes in kidney, liver, thoracic artery, and brain whereas Group 1 did not reveal any abnormalities on histopathology. We therefore concluded that arsenic induces histological alterations in the tested organs.

6.
Cancer Immunol Immunother ; 60(10): 1439-46, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21644032

ABSTRACT

An ADP ribosylation factor-GTPase activating protein (ASAP1) is highly expressed in a variety of tumor cells and is involved in the cell motility, invasion, and metastasis. In order to elucidate the involvement of ASAP1 in lipopolysaccharide (LPS)-mediated inflammatory response, the effect of ASAP1 silencing on LPS-induced proinflammatory mediators production was examined by using RAW 264.7 macrophage-like cells. ASAP1 was constitutively expressed in the cells and the expression was augmented by LPS stimulation. Silencing of ASAP1 with small interfering RNA enhanced the production of tumor necrosis factor-α, interleukin 6, interferon-ß, and nitric oxide in response to LPS. ASAP1 silencing augmented the activation of nuclear factor (NF)-κB and several mitogen-activated protein kinases (MAPKs). On the other hand, ASAP1 silencing did not affect the expression of IRAK4, TRAF6, and Akt as the upstream molecules of NF-κB signaling. A series of toll-like receptor ligands as well as LPS augmented the ASAP1 expression. Taken together, ASAP1 was suggested to negatively regulate LPS-induced proinflammatory mediators production through down-regulating LPS signaling. The feedback function of ASAP1 in LPS-mediated inflammatory response is discussed.


Subject(s)
Adaptor Proteins, Signal Transducing/immunology , Lipopolysaccharides/immunology , Signal Transduction/immunology , Adaptor Proteins, Signal Transducing/metabolism , Animals , Cell Line , Cytokines/biosynthesis , Cytokines/immunology , Immunoblotting , Inflammation/immunology , Inflammation/metabolism , Macrophages/immunology , Macrophages/metabolism , Mice , RNA, Small Interfering , Reverse Transcriptase Polymerase Chain Reaction
7.
Microbiol Immunol ; 55(3): 160-7, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21204955

ABSTRACT

Flavopiridol is a cyclin-dependent kinase inhibitor and inhibits the growth of various cancer cells. The effect of flavopiridol on lipopolysaccharide (LPS)-induced proinflammatory mediator production was examined in RAW 264.7 macrophage-like cells. Flavopiridol significantly reduced the production of tumor necrosis factor-α and, to a lesser extent, nitric oxide in LPS-stimulated cells. Flavopiridol inhibited the activation of nuclear factor-κB and IκB kinase in response to LPS. Flavopiridol also inhibited the activation of a series of mitogen-activated protein kinases, such as p38, stress-activated protein kinase/c-Jun N-terminal kinase and extracellular signal-regulated kinase 1/2 in response to LPS. However, flavopiridol did not alter the expression of tumor necrosis factor receptor-associated factor 6, myeloid differentiation factor 88 (MyD88) or CD14/toll-like receptor (TLR) 4. Flavopiridol inhibited nitric oxide production induced by a MyD88-dependent TLR2 ligand, but not a MyD88-independent TLR3 ligand. Further, flavopiridol did not alter the phosphorylation of interferon regulatory factor 3 in the MyD88-independent pathway. Therefore, it was suggested that flavopiridol exclusively inhibited the activation of nuclear factor-κB and mitogen-activated protein kinases in the MyD88-dependent pathway. Flavopiridol might be useful for the prevention of LPS-induced inflammatory response.


Subject(s)
Flavonoids/pharmacology , Gene Expression Regulation, Archaeal/drug effects , Lipopolysaccharides/metabolism , Mitogen-Activated Protein Kinases/metabolism , Myeloid Differentiation Factor 88/metabolism , NF-kappa B/metabolism , Piperidines/pharmacology , Protein Kinase Inhibitors/pharmacology , Tumor Necrosis Factor-alpha/biosynthesis , Animals , Cell Line , Lipopolysaccharide Receptors/metabolism , Macrophages/drug effects , Mice , Nitric Oxide/biosynthesis , Phosphorylation/drug effects , Signal Transduction/drug effects , TNF Receptor-Associated Factor 6/metabolism , Toll-Like Receptors/metabolism
8.
Cell Immunol ; 264(2): 114-8, 2010.
Article in English | MEDLINE | ID: mdl-20557878

ABSTRACT

The involvement of retinoblastoma protein-interacting zinc finger 1 (RIZ1), a tumor suppressor, in lipopolysaccharide (LPS)-induced inflammatory responses was investigated by using RAW 264.7 macrophage-like cells. LPS significantly augmented the expression of RIZ1 and the augmentation was mediated by the activation of nuclear factor (NF)-kappaB and Akt. The silencing of RIZ1 with the siRNA led to the inactivation of NF-kappaB in response to LPS. Moreover, the RIZ1 silencing caused the down-regulation of p53 activation and a p53 pharmacological inhibitor attenuated the RIZ1 expression. LPS-induced tumor necrosis factor-alpha and interleukin-6 production was prevented by RIZ1 siRNA or a p53 pharmacological inhibitor. Therefore, RIZ1 was suggested to augment LPS-induced NF-kappaB activation in collaboration with p53 and enhance the production of proinflammatory cytokines in response to LPS.


Subject(s)
Histone-Lysine N-Methyltransferase/metabolism , Interleukin-6/biosynthesis , Macrophages/metabolism , NF-kappa B/metabolism , Transcription Factors/metabolism , Tumor Necrosis Factor-alpha/biosynthesis , Animals , Cell Line , Cloning, Molecular , Histone-Lysine N-Methyltransferase/genetics , Histone-Lysine N-Methyltransferase/immunology , Inflammation , Interleukin-6/genetics , Interleukin-6/metabolism , Lipopolysaccharides/immunology , Lipopolysaccharides/metabolism , Macrophages/immunology , Macrophages/pathology , Mice , Mutation/genetics , NF-kappa B/genetics , RNA, Small Interfering/genetics , Transcription Factors/genetics , Transcription Factors/immunology , Transcriptional Activation/genetics , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/metabolism , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism
9.
Immunol Lett ; 131(2): 166-9, 2010 Jul 08.
Article in English | MEDLINE | ID: mdl-20417662

ABSTRACT

The role of retinoblastoma protein-interacting zinc finger 1 (RIZ1) in receptor activator of NF-kappaB ligand (RANKL)-induced osteoclast formation was examined in mouse RAW 264.7 macrophage-like cells. The expression of RIZ1 was significantly augmented by RANKL-treated cells. Silencing of RIZ1 with the siRNA significantly reduced the appearance of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells as osteoclasts in RANKL-treated cells. The expression of nuclear factor of activated T cell 1 (NFATc1) as the terminal transcription factor of osteoclast formation was prevented by RIZ1 siRNA. It was suggested that that RIZ1 might participate in RANKL-induced osteoclast formation through the regulation of NFATc1 expression.


Subject(s)
Histone-Lysine N-Methyltransferase/metabolism , Macrophages/metabolism , NFATC Transcription Factors/biosynthesis , Neoplasms/metabolism , Osteoclasts/metabolism , Transcription Factors/metabolism , Acid Phosphatase/biosynthesis , Animals , Antigens, Differentiation/biosynthesis , Bone Resorption , Cell Line , Gene Expression Regulation , Histone-Lysine N-Methyltransferase/genetics , Histone-Lysine N-Methyltransferase/immunology , Isoenzymes/biosynthesis , Macrophages/immunology , Macrophages/pathology , Mice , NFATC Transcription Factors/genetics , Neoplasms/pathology , Neoplasms/physiopathology , Osteoclasts/immunology , Osteoclasts/pathology , RANK Ligand/metabolism , RNA, Small Interfering/genetics , Signal Transduction/genetics , Signal Transduction/immunology , Tartrate-Resistant Acid Phosphatase , Transcription Factors/genetics , Transcription Factors/immunology
10.
Immunology ; 129(1): 97-104, 2010 Jan.
Article in English | MEDLINE | ID: mdl-20050332

ABSTRACT

The regulatory role of tumour necrosis factor-a (TNF-a) on the expression of suppressor of cytokine signalling 3 (SOCS-3) in response to lipopolysaccharide (LPS) was examined using peritoneal macrophages from TNF-a-deficient mice. The LPS-induced SOCS-3 expression was markedly augmented in macrophages from wild-type mice whereas such augmentation was not seen in the cells from TNF-a-deficient mice. However, there was no significant difference in the level of SOCS-3 messenger RNA expression between macrophages from wild-type mice and those from TNF-a-deficient mice. The addition of exogenous TNF-a augmented the LPS-induced SOCS-3 expression in macrophages from TNF-a-deficient mice. The pulse chase analysis suggested augmented degradation of LPS-induced SOCS-3 protein in macrophages from TNF-a-deficient mice. Moreover, MG 132, a 26S proteasome inhibitor, sustained the LPS-induced SOCS-3 expression in those cells. The tyrosine phosphorylation of SOCS-3 was definitely induced in LPS-stimulated macrophages from TNF-a-deficient mice but not wild-type mice. A tyrosine phosphatase inhibitor enhanced the tyrosine phosphorylation of SOCS-3 in wild-type mice and accelerated the degradation. Therefore, it was suggested that TNF-a prevented the degradation of SOCS-3 protein via inhibition of the tyrosine phosphorylation in LPS-stimulated macrophages.


Subject(s)
Macrophages, Peritoneal/metabolism , Protein Tyrosine Phosphatases/metabolism , Recombinant Proteins/pharmacology , Suppressor of Cytokine Signaling Proteins/biosynthesis , Tumor Necrosis Factor-alpha/pharmacology , Animals , Cells, Cultured , Cysteine Proteinase Inhibitors/pharmacology , Leupeptins/pharmacology , Lipopolysaccharides/pharmacology , Macrophages, Peritoneal/drug effects , Macrophages, Peritoneal/immunology , Macrophages, Peritoneal/pathology , Male , Mice , Mice, Knockout , Phosphorylation , Protein Stability/drug effects , Suppressor of Cytokine Signaling 3 Protein , Suppressor of Cytokine Signaling Proteins/genetics , Suppressor of Cytokine Signaling Proteins/immunology , Tumor Necrosis Factor-alpha/genetics
11.
Innate Immun ; 15(4): 217-24, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19586995

ABSTRACT

The inhibitory effect of interleukin-10 (IL-10), an anti-inflammatory cytokine, on lipopolysaccharide (LPS)-induced IL-6 production was characterized by simultaneous stimulation of RAW 264.7 cells with LPS and IL-10. The presence of IL-10 significantly inhibited LPS-induced IL-6 production at a transcriptional level. The expression of IkappaB-zeta, which promotes IL-6 production, was induced in response to LPS and it was definitely suppressed in the presence of IL-10. Further, IL-10 inhibited LPS-induced NF-kappaB activation. A pharmacological inhibitor of NF-kappaB prevented LPS-induced IkappaB-zeta expression, suggesting that IL-10 might inhibit LPS-induced IkappaB-zeta expression via the inactivation of NF-kappaB. In LPS- and IL-10-stimulated cells, the expression of Bcl-3 that inhibits NF-kappaB activation was significantly augmented. Introduction of Bcl-3 siRNA abolished IL-10-mediated IkappaB-zeta inhibition. In the presence of Bcl-3, siRNA IL-10 failed to inhibit LPS-induced IL-6 production. Therefore, it was suggested that Bcl-3 induced by IL-10 might reduce LPS-induced IkappaB-zeta activity via inactivation of NF-kappaB and that reduced IkappaB-zeta activity failed to promote LPS-induced IL-6 production.


Subject(s)
Interleukin-10/pharmacology , Interleukin-6/biosynthesis , Nuclear Proteins/metabolism , Proto-Oncogene Proteins/metabolism , Recombinant Proteins/pharmacology , Transcription Factors/metabolism , Adaptor Proteins, Signal Transducing , Animals , Aspirin/pharmacology , B-Cell Lymphoma 3 Protein , Cell Line , Down-Regulation/drug effects , Down-Regulation/genetics , Down-Regulation/immunology , Interleukin-6/genetics , Interleukin-6/metabolism , Lipopolysaccharides/immunology , Lipopolysaccharides/metabolism , Macrophage Activation/drug effects , Macrophage Activation/genetics , Macrophage Activation/immunology , Mice , NF-kappa B/antagonists & inhibitors , Nuclear Proteins/genetics , Nuclear Proteins/immunology , Proto-Oncogene Proteins/genetics , Proto-Oncogene Proteins/immunology , RNA, Small Interfering/genetics , Signal Transduction/drug effects , Signal Transduction/genetics , Signal Transduction/immunology , Transcription Factors/genetics , Transcription Factors/immunology , Transcriptional Activation/drug effects , Transcriptional Activation/genetics , Transcriptional Activation/immunology , Tumor Necrosis Factor-alpha/biosynthesis , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/metabolism
12.
Int J Med Microbiol ; 299(8): 554-62, 2009 Dec.
Article in English | MEDLINE | ID: mdl-19467928

ABSTRACT

The effect of Clostridium perfringens alpha-toxin on production of tumor necrosis factor (TNF)-alpha and nitric oxide (NO) in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells was studied. The pretreatment of wild type alpha-toxin, but not the inactive mutant, significantly decreased LPS-induced TNF-alpha and NO production. alpha-Toxin inhibited the expression of TNF-alpha and an inducible type of NO synthase protein and mRNA. Furthermore, it inhibited the phosphorylation of IkappaB-alpha and p65 NF-kappaB subunit, and the NF-kappaB luciferase reporter gene activity in LPS-stimulated cells. The pretreatment of alpha-toxin increased the level of intracellular ceramide. Taken together, Clostridium perfringens alpha-toxin pretreatment was suggested to inhibit LPS-induced TNF-alpha and NO production through the inhibition of NF-kappaB activation. The relationship between alpha-toxin-induced intracellular ceramide generation and the NF-kappaB inhibition is discussed.


Subject(s)
Bacterial Toxins/immunology , Bacterial Toxins/metabolism , Calcium-Binding Proteins/immunology , Calcium-Binding Proteins/metabolism , Ceramides/metabolism , Lipopolysaccharides/immunology , Nitric Oxide/antagonists & inhibitors , Tumor Necrosis Factor-alpha/antagonists & inhibitors , Type C Phospholipases/immunology , Type C Phospholipases/metabolism , Animals , Cell Line , Gene Expression Regulation/drug effects , Genes, Reporter , I-kappa B Kinase/metabolism , Luciferases/biosynthesis , Luciferases/genetics , Macrophages/chemistry , Macrophages/drug effects , Macrophages/immunology , Mice , Phosphorylation , Transcription Factor RelA/metabolism
13.
Microbiol Immunol ; 53(5): 295-300, 2009 May.
Article in English | MEDLINE | ID: mdl-19457171

ABSTRACT

Nystatin is known to deplete lipid rafts from mammalian cell membranes. Lipid rafts have been reported to be necessary for lipopolysaccharide signaling. In this study, it was unexpectedly found that lipopolysaccharide-induced nitric oxide production was not inhibited, but rather increased in the presence of a non-cytotoxic concentration of nystatin. Surprisingly, treatment with nystatin induced only NO production and iNOS expression in RAW264.7 cells. At the concentration used, no changes in the expression of GM1 ganglioside, a lipid raft marker on RAW264.7 cells, was seen. From studies using several kinds of inhibitors for signaling molecules, nystatin-induced NO production seems to occur via the ikappaB/NF-kappaB and the PI3 K/Akt pathway. Furthermore, because nystatin is known to activate the Na-K pump, we examined whether the Na-K pump inhibitor amiloride suppresses nystatin-induced NO production. It was found that amiloride significantly inhibited nystatin-induced NO production. The results suggest that a moderate concentration of nystatin induces NO production by Na-pump activation through the PI3 kinase/Akt/NF-kappaB pathway without affecting the condition of lipid rafts.


Subject(s)
Macrophages/drug effects , Macrophages/immunology , Nitric Oxide/immunology , Nystatin/pharmacology , Animals , Cell Line , Gangliosides/immunology , I-kappa B Kinase/immunology , Mice , NF-kappa B/immunology , Signal Transduction
14.
Mycobiology ; 35(1): 25-9, 2007 Mar.
Article in English | MEDLINE | ID: mdl-24015064

ABSTRACT

A newly synthesized Nickel (II) tyrosine complex was screened as potential antimicrobial agent against a number of medically important bacteria (Bacillus subtilis, Streptococcus ß-haemolytica, Escherichia coli, Shigella dysenterae) and fungi (Aspergillus fumigatus, Candida albicans, Aspergillus niger, Aspergillus flavus, Penicillium sp.) strains. were used for antifungal activity. The antimicrobial activity was evaluated using the Agar Disc method. Moreover, the minimum inhibitory concentration of the complexes was determined against the same pathogenic bacteria and the values were found between 4~64 µg ml (-1). Brine shrimp bioassay was carried out for cytotoxicity measurements of the complexes. The LC50 values were calculated after probit transformation of the resulting mortality data and found to be 6 µg ml (-1).

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