Efecto del extracto de alcaloides de Berberis darwinii Hook sobre respuestas celulares innatas en fagocitos murinos / Effect of the extract of Berberis darwinii Hook alkaloids on innate cellular responses in murine phagocytes

Berberis darwinii Hook es una especie que habita el sur de Chile y la Patagonia. Siendo utilizada por la etnia mapuche para el tratamiento de procesos inflamatorios, estados febriles, y dolor estomacal. El propósito del siguiente estudio fue evaluar in vitro las propiedades del extracto de alcaloides de raíz de B. darwinii sobre respuestas celulares en monocitos desde sangre periférica de rata. Los resultados de la cuantificación del extracto muestran una concentración de alcaloides totales de 1,67 mg/g y la caracterización por HPLC- MS determinó la presencia de berberina y palmatina. In vitro se observó que los extractos disminuyeron la capacidad de adhesión y la actividad fagocítica de los monocitos e inhibieron la translocación del factor nuclear NF-κB asociado a la modulación de la inflamación, pero no así la producción de anión superóxido. Estos resultados indicarían que los alcaloides totales de B. darwinii inhiben algunos mecanismos específicos de defensa celular.

Berberis darwinii Hook is a species that inhabits southern Chile and Patagonia. This is being used by the Mapuche ethnic group for the treatment of inflammatory processes, febrile states, and stomach pain. The purpose of the following study was to evaluate in vitro the properties of an alkaloid extract of B. darwinii root on cellular responses in monocytes from the rat peripheral blood. The results of the quantification of the extract showed a total alkaloid concentration of 1.67 mg/g and the characterization by HPLC-MS determined the presence of berberine and palmatine. In vitro, it was observed that the extracts decreased the adhesion capacity and phagocytic activity of the monocytes and inhibited the translocation of the nuclear factor NF-κB associated with the modulation of inflammation, but not the production of superoxide anion. These results indicate that the total alkaloids of B. darwinii inhibit some specific mechanisms of cellular defense.

Circulatory and Ventilatory Power: Characterization in Patients with Coronary Artery Disease / Potência Circulatória e Ventilatória: Caracterização em Pacientes com Doença Arterial Coronariana

Background: Circulatory power (CP) and ventilatory power (VP) are indices that have been used for the clinical evaluation of patients with heart failure; however, no study has evaluated these indices in patients with coronary artery disease (CAD) without heart failure. Objective: To characterize both indices in patients with CAD compared with healthy controls. Methods: Eighty-seven men [CAD group = 42 subjects and healthy control group (CG) = 45 subjects] aged 40–65 years were included. Cardiopulmonary exercise testing was performed on a treadmill and the following parameters were measured: 1) peak oxygen consumption (VO2), 2) peak heart rate (HR), 3) peak blood pressure (BP), 4) peak rate-pressure product (peak systolic HR x peak BP), 5) peak oxygen pulse (peak VO2/peak HR), 6) oxygen uptake efficiency (OUES), 7) carbon dioxide production efficiency (minute ventilation/carbon dioxide production slope), 8) CP (peak VO2 x peak systolic BP) and 9) VP (peak systolic BP/carbon dioxide production efficiency). Results: The CAD group had significantly lower values for peak VO2 (p < 0.001), peak HR (p < 0.001), peak systolic BP (p < 0.001), peak rate-pressure product (p < 0.001), peak oxygen pulse (p = 0.008), OUES (p < 0.001), CP (p < 0.001), and VP (p < 0.001) and significantly higher values for peak diastolic BP (p = 0.004) and carbon dioxide production efficiency (p < 0.001) compared with CG. Stepwise regression analysis showed that CP was influenced by group (R2 = 0.44, p < 0.001) and VP was influenced by both group and number of vessels with stenosis after treatment (interaction effects: R2 = 0.46, p < 0.001). Conclusion: The indices CP and VP were lower in men with CAD than healthy controls. .

Fundamento: Os índices da Potência Circulatória (PC) e Potência Ventilatória (PV) têm sido utilizados para avaliação clínica de pacientes com insuficiência cardíaca, mas nenhum estudo avaliou esses índices em pacientes com Doença Arterial Coronariana (DAC). Objetivo: Caracterizar ambos os índices em pacientes com DAC comparados a indivíduos saudáveis. Métodos: Oitenta e sete homens [grupo DAC = 42 sujeitos e, grupo controle (GC) = 45 sujeitos] com idade entre 45 e 65 anos foram incluídos. Um Teste de Exercício Cardiopulmonar (TECP) foi realizado em esteira e as seguintes variáveis foram obtidas: 1) consumo de oxigênio (VO2) pico; 2) Frequência Cardíaca (FC) pico; 3) Pressão Arterial (PA) pico; 4) duplo produto pico (PA sistólica pico x FC pico); 5) pulso de oxigênio pico (VO2 pico dividido pela FC pico); 6) eficiência ventilatória para o consumo de oxigênio (OUES); 7) eficiência ventilatória para a produção de dióxido de carbono (VE/VCO2 slope); 8) PC (VO2 pico x PA sistólica pico); e 9) PV (PA sistólica pico dividido pelo VE/VCO2 slope). Resultados: O grupo DAC apresentou valores significativamente menores das seguintes variáveis no pico do exercício: VO2 (p < 0,001), FC (p < 0,001), PA sistólica (p < 0,001), duplo produto (p < 0,001), pulso de oxigênio (p = 0,008), OUES (p < 0,001), PC (p < 0,001) e PV (p < 0,001), e valores significativamente maiores de PA diastólica (p = 0,004) e VE/VCO2 slope (p < 0,001) em relação ao GC. Uma análise de regressão pelo método stepwise mostrou que a PC foi influenciada pelo grupo (R2 = 0,44, p < 0,001) e a PV tanto pelo grupo quanto pelo número de vasos com estenose pós tratamento (efeito de interação: R2 = 0,46, p < 0,001). Conclusion: Os índices da PC e PV foram menores em homens com DAC comparados ao GC, podendo dessa forma ser utilizados na caracterização dessa população. .

Cell accumulation and antileishmanial effect of exogenous and endogenous protoporphyrin IX after photodynamic treatment / Acumulación celular y efecto anti- Leishmania de la protoporfirina IX exógena y endógena después del tratamiento fotodinámico

Introduction: Photodynamic therapy (PDT) using 5-aminolevulinic acid-induced protoporphyrin IX (ALA-PpIX) constitutes an interesting alternative for cutaneous leishmaniasis treatment. Objective: To evaluate the production of PpIXbased on the administration of ALA and MAL and the effect of ALA-PDTat cellular level on non-infected and infected THP-1 cells using Leishmania ( Viannia ) panamensis or Leishmania ( Leishmania ) infantum (syn Leishmania chagasi ) parasites. Materials and methods: Protoporphyrin IX (PpIX) production and mitochondrial colocalization were evaluated by confocal microscopy. Cell toxicities were evaluated after treatment with the compounds, followed by light irradiation (597-752 nm) at 2.5 J/cm 2 fluency using a colorimetric MTT assay for THP-1 cells and a standard microscopic analysis of parasites. Results were expressed as compound concentration activity against 50% of cells or parasites (CC 50 or IC 50 ). Results: ALA or MAL induced an endogenous PpIX with a red fluorescence localized mainly in the mitochondria inside human cells. ALA and MAL-PDT induced a similar range of toxicities on THP-1 cells (CC 50 0.16±0.01mM and 0.33±0.019 mM, respectively) without any apparent inhibition of intracellular parasites in the infected cells as compared to untreated controls. Exogenous PpIX-PDT was toxic to THP-1 cells (CC 50 0.00032±0.00002 mM), L. (L.) infantum (IC 50 0.003±0.0001 mM) and L. (V.) panamensis (IC 50 0.024±0.0001 mM) promastigotes. Conclusions: Despite the effectiveness of exogenous PpIX on promastigotes and the production of PpIX by human infected cells, treatment with ALA or MAL before irradiation was unable to completely destroy L. (L.) infantum or L. (V.) panamensis intracellular amastigotes.

Introducción. El tratamiento fotodinámico con ácido 5-aminolevulínico como inductor de la protoporfirina IX (ALA-PpIX) constituye una alternativa interesante en el tratamiento de la leishmaniasis cutánea. Objetivo. Evaluar la producción de protoporfirina IX (PpIX) a partir de la administración de ALA o MAL y el efecto de la PDT con ALA a nivel celular en células THP-1 no infectadas e infectadas con Leishmania ( Viannia ) panamensis o Leishmania ( Leishmania ) infantum (syn. Leishmania chagasi ). Materiales y métodos. La producción de protoporfirina IX y su ‘colocalización´ mitocondrial se evaluaron mediante microscopía ‘confocal´. Se evaluó la toxicidad celular después del tratamiento con los compuestos y la aplicación de irradiación de luz (597-752 nm) en una fluencia de 2,5 J/cm 2 mediante el empleo de la prueba colorimétrica con metil-tiazol-tetrazolio (MTT) en las células, y de métodos microscópicos estándar en los parásitos. Los resultados se expresaron como la concentración del compuesto activo en el 50 % de las células o parásitos (CC 50 o CI 50 ). Resultados. El ácido aminolevulínico o el metil-5-aminolevulinato indujeron la protoporfirina IX endógena en células humanas, y se observó fluorescencia de color rojo en las mitocondrias. La actividad del ácido aminolevulínico y del metil-5-aminolevulinato utilizados con terapia fotodinámica fue similar en las células THP-1 (CC 50 0,16±0,01 mM y 0,33±0,019 mM, respectivamente) y, aparentemente, no inhibió los parásitos en las células infectadas, en comparación con los controles. El tratamiento exógeno con protoporfirina IX y terapia fotodinámica fue tóxico para las células THP-1 (CC 50 0,00032 ±0,00002 mM) y para los promastigotes de L. (L .) infantum (IC 50 0,003±0,0001 mM) y L. ( V .) panamensis (CI 50 0,024±0,0001 mM). Conclusiones. A pesar de la ‘fotoactividad´ del tratamiento con protoporfirina IX en promastigotes y de su producción después del tratamiento con ácido aminolevulínico y metil-5-aminolevulinato en las células infectadas con Leishmania , no se observó daño en los amastigotes presentes en las células de L. ( L .) infantum o L . ( V .) panamensis .

Diclofenac topical gel in excisional wounds maintain heal quality and reduce phlogistic signals1

PURPOSE: To investigate diclofenac topical gel as an alternative to reduce phlogistic signals and maintain quality of wound repair. METHODS: Fifteen Wistar rats were used in this study; four excisional wounds were performed on the dorsum of each animal. Once in a day, cranial wounds received topical diclofenac gel administration and caudal wounds were washed with isotonic saline. After seven, 14 and 21 postoperative days, five animals were randomly chosen for macroscopic and microscopic wound analysis. RESULTS: On the 7th day: diclofenac wounds showed significant higher scab formation, however showed less phlogistic signal; diclofenac wounds had larger area and had less neutrophil invasion. On the 14th day: No area difference was noted and diclofenac wounds showed less hyperemia and phlogistic signals; diclofenac wounds showed greater keratinocytes invasion. On the 21st day: Almost all wounds were closed and there were no difference regarding the type of scar formation; diclofenac wounds showed greater monocytes invasion and lower angiogenesis level. No difference was noted in any postoperative day regarding fibroblast invasion, collagen deposit quantity and quality. CONCLUSION: Diclofenac topical gel is capable of reducing phlogistic signals and do not cause fibroblast or keratinocyte downregulation thus do not lead to excisional wound healing impairment. .

KR-31543 reduces the production of proinflammatory molecules in human endothelial cells and monocytes and attenuates atherosclerosis in mouse model

KR-31543, (2S, 3R, 4S)-6-amino-4-[N-(4-chlorophenyl)-N-(2-methyl-2H-tetrazol-5-ylmethyl) amino]-3,4-dihydro-2-dimethyoxymethyl-3-hydroxy-2-methyl-2H-1-benz opyran is a new neuroprotective agent for ischemia-reperfusion damage. It has also been reported that KR-31543 has protective effects on lipid peroxidation and H2O2-induced reactive oxygen species production. In this study, we investigated the anti-inflammatory and anti-atherogenic properties of KR-31543. We observed that KR-31543 treatment reduced the production of MCP-1, IL-8, and VCAM-1 in HUVECs, and of MCP-1 and IL-6 in THP-1 human monocytes. We also examined the effect of KR-31543 on monocytes migration in vitro. KR-31543 treatment effectively reduced the migration of THP-1 human monocytes to the HUVEC monolayer in a dose-dependent manner. We next examined the effects of this compound on atherogenesis in LDL receptor deficient (Ldlr-/-) mice. After 10 weeks of western diet, the formation of atherosclerotic lesion in aorta was reduced in the KR-31543-treated group compared to the control group. The accumulation of macrophages in lesion was also reduced in KR-31543 treated group. However, the plasma levels of total cholesterol, HDL, LDL, and triglyceride were not affected by KR-31543 treatment. Taken together, these results show that KR-31543 has anti-inflammatory properties on human monocytes and endothelial cells, and inhibits fatty streak lesion formation in mouse model of atherosclerosis, suggesting the potential of KR-31543 for the treatment for atherosclerosis.

High-density lipoprotein prevents SAA-induced production of TNF-α in THP-1 monocytic cells and peripheral blood mononuclear cells

In this study, we evaluated whether human serum and lipoproteins, especially high-density lipoprotein (HDL), affected serum amyloid A (SAA)-induced cytokine release. We verified the effects of SAA on THP-1 cells in serum-free medium compared to medium containing human serum or lipoprotein-deficient serum. SAA-induced tumour necrosis factor-alpha (TNF-α) production was higher in the medium containing lipoprotein-deficient serum than in the medium containing normal human serum. The addition of HDL inhibited the SAA-induced TNF-α release in a dose-dependent manner. This inhibitory effect was specific for HDL and was not affected by low-density lipoprotein or very low-density lipoprotein. In human peripheral blood mononuclear cells, the inhibitory effect of HDL on TNF-α production induced by SAA was less pronounced. However, this effect was significant when HDL was added to lipoprotein-deficient medium. In addition, a similar inhibitory effect was observed for interleukin-1 beta release. These findings confirm the important role of HDL and support our previous hypothesis that HDL inhibits the effects of SAA during SAA transport in the bloodstream. Moreover, the HDL-induced reduction in the proinflammatory activity of SAA emphasizes the involvement of SAA in diseases, such as atherosclerosis, that are characterized by low levels of HDL.

Angiotensin II induces NF-κB, JNK and p38 MAPK activation in monocytic cells and increases matrix metalloproteinase-9 expression in a PKC- andRho kinase-dependent manner

Angiotensin II (ANG II), the main effector of the renin-angiotensin system, is implicated in endothelial permeability, recruitment and activation of the immune cells, and also vascular remodeling through induction of inflammatory genes. Matrix metalloproteinases (MMPs) are considered to be important inflammatory factors. Elucidation of ANG II signaling pathways and of possible cross-talks between their components is essential for the development of efficient inhibitory medications. The current study investigates the inflammatory signaling pathways activated by ANG II in cultures of human monocytic U-937 cells, and the effects of specific pharmacological inhibitors of signaling intermediates on MMP-9 gene (MMP-9) expression and activity. MMP-9 expression was determined by real-time PCR and supernatants were analyzed for MMP-9 activity by ELISA and zymography methods. A multi-target ELISA kit was employed to evaluate IκB, NF-κB, JNK, p38, and STAT3 activation following treatments. Stimulation with ANG II (100 nM) significantly increased MMP-9 expression and activity, and also activated NF-κB, JNK, and p38 by 3.8-, 2.8- and 2.2-fold, respectively (P < 0.01). ANG II-induced MMP-9 expression was significantly reduced by 75 and 67 percent, respectively, by co-incubation of the cells with a selective inhibitor of protein kinase C (GF109203X, 5 µM) or of rho kinase (Y-27632, 15 µM), but not with inhibitors of phosphoinositide 3-kinase (wortmannin, 200 nM), tyrosine kinases (genistein, 100 µM) or of reactive oxygen species (α-tocopherol, 100 µM). Thus, protein kinase C and Rho kinase are important components of the inflammatory signaling pathways activated by ANG II to increase MMP-9 expression in monocytic cells. Both signaling molecules may constitute potential targets for effective management of inflammation.

Lipopolysaccharide-induced expression of cell surface receptors and cell activation of neutrophils and monocytes in whole human blood

Lipopolysaccharide (LPS) activates neutrophils and monocytes, inducing a wide array of biological activities. LPS rough (R) and smooth (S) forms signal through Toll-like receptor 4 (TLR4), but differ in their requirement for CD14. Since the R-form LPS can interact with TLR4 independent of CD14 and the differential expression of CD14 on neutrophils and monocytes, we used the S-form LPS from Salmonella abortus equi and the R-form LPS from Salmonella minnesota mutants to evaluate LPS-induced activation of human neutrophils and monocytes in whole blood from healthy volunteers. Expression of cell surface receptors and reactive oxygen species (ROS) and nitric oxide (NO) generation were measured by flow cytometry in whole blood monocytes and neutrophils. The oxidative burst was quantified by measuring the oxidation of 2',7'-dichlorofluorescein diacetate and the NO production was quantified by measuring the oxidation of 4-amino-5-methylamino-2',7'-difluorofluorescein diacetate. A small increase of TLR4 expression by monocytes was observed after 6 h of LPS stimulation. Monocyte CD14 modulation by LPS was biphasic, with an initial 30 percent increase followed by a 40 percent decrease in expression after 6 h of incubation. Expression of CD11b was rapidly up-regulated, doubling after 5 min on monocytes, while down-regulation of CXCR2 was observed on neutrophils, reaching a 50 percent reduction after 6 h. LPS induced low production of ROS and NO. This study shows a complex LPS-induced cell surface receptor modulation on human monocytes and neutrophils, with up- and down-regulation depending on the receptor. R- and S-form LPS activate human neutrophils similarly, despite the low CD14 expression, if the stimulation occurs in whole blood.

Human monocytes tolerant to LPS retain the ability to phagocytose bacteria and generate reactive oxygen species

Tolerance to lipopolysaccharide (LPS) occurs when animals or cells exposed to LPS become hyporesponsive to a subsequent challenge with LPS. This mechanism is believed to be involved in the down-regulation of cellular responses observed in septic patients. The aim of this investigation was to evaluate LPS-induced monocyte tolerance of healthy volunteers using whole blood. The detection of intracellular IL-6, bacterial phagocytosis and reactive oxygen species (ROS) was determined by flow cytometry, using anti-IL-6-PE, heat-killed Staphylococcus aureus stained with propidium iodide and 2',7'-dichlorofluorescein diacetate, respectively. Monocytes were gated in whole blood by combining FSC and SSC parameters and CD14-positive staining. The exposure to increasing LPS concentrations resulted in lower intracellular concentration of IL-6 in monocytes after challenge. A similar effect was observed with challenge with MALP-2 (a Toll-like receptor (TLR)2/6 agonist) and killed Pseudomonas aeruginosa and S. aureus, but not with flagellin (a TLR5 agonist). LPS conditioning with 15 ng/mL resulted in a 40 percent reduction of IL-6 in monocytes. In contrast, phagocytosis of P. aeruginosa and S. aureus and induced ROS generation were preserved or increased in tolerant cells. The phenomenon of tolerance involves a complex regulation in which the production of IL-6 was diminished, whereas the bacterial phagocytosis and production of ROS was preserved. Decreased production of proinflammatory cytokines and preserved or increased production of ROS may be an adaptation to control the deleterious effects of inflammation while preserving antimicrobial activity.

Grifola frondosa water extract alleviates intestinal inflammation by suppressing TNF-alpha production and its signaling

TNF-alpha is a major cytokine involved in inflammatory bowel disease (IBD). In this study, water extract of Grifola frondosa (GFW) was evaluated for its protective effects against colon inflammation through the modulation of TNF-alpha action. In coculture of HT-29 human colon cancer cells with U937 human monocytic cells, TNF-alpha-induced monocyte adhesion to HT-29 cells was significantly suppressed by GFW (10, 50, 100 microg/ml). The reduced adhesion by GFW correlated with the suppressed expression of MCP-1 and IL-8, the major IBD-associated chemokines. In addition, treatment with GFW significantly suppressed TNF-alpha-induced reactive oxygen species production and NF-kappaB transcriptional activity in HT-29 cells. In differentiated U937 monocytic cells, LPS-induced TNF-alpha production, which is known to be mediated through NF-kappaB activation, was significantly suppressed by GFW. In an in vivo rat model of IBD, oral administration of GFW for 5 days (1 g/kg per day) significantly inhibited the trinitrobenzene sulfonic acid (TNBS)-induced weight loss, colon ulceration, myeloperoxidase activity, and TNF-alpha expression in the colon tissue. Moreover, the effect of GFW was similar to that of intra-peritoneal injection of 5-aminosalicylic acid (5-ASA), an active metabolite of sulfasalazine, commonly used drug for the treatment of IBD. The results suggest that GFW ameliorates colon inflammation by suppressing production of TNF-alpha as well as its signaling through NF-kappaB leading to the expression of inflammatory chemokines, MCP-1 and IL-8. Taken together, the results strongly suggest GFW is a valuable medicinal food for IBD treatment, and thus may be used as an alternative medicine for IBD.

Cytotoxicity evaluation of two root canal sealers and a commercial calcium hydroxide paste on THP1 cell line by Trypan Blue assay

OBJECTIVE: The aim of this investigation was to evaluate the cytotoxicity of two brands of root canal sealers, epoxy-resin based and zinc oxide-eugenol based, and one commercial calcium hydroxide paste on a monocyte cell line THP-1. MATERIAL AND METHODS: Undiluted (crude extract) and diluted extracts to 10 percent, 1 percent, 0.1 percent, 0.01 percent, 0.001 percent and 0.0001 percent of the sealers were tested for cytotoxicity to THP-1 cells using the trypan blue assay. Extracts were obtained according to ISO standard. Data were analyzed statistically by the Kruskal-Wallis and Mann-Whitney tests at 5 percent significance level. RESULTS: Crude extract of AH Plus and Fill Canal killed approximately 90 percent of THP-1 cells versus 36 percent of THP-1 cells killed by L&C crude extract (p<0.05). Ten-fold dilutions of L&C, Fill Canal and AH Plus killed 24, 35 and 61 percent of THP-1 cells (p<0.05), respectively. Dilutions lesser than 1 percent caused minimal cell death as compared to the control groups (p>0.05), except for L&C 1 percent extract. CONCLUSIONS: The results revealed that the L&C paste crude extract was less cytotoxic to THP-1 cells than AH Plus or Fill Canal crude extracts.

Lysophosphatidylglycerol inhibits formyl peptide receptor like-1-stimulated chemotactic migration and IL-1beta production from human phagocytes

In this study, we observed that lysophosphatidylglycerol (LPG) completely inhibited a formyl peptide receptor like-1 (FPRL1) agonist (MMK-1)-stimulated chemotactic migration in human phagocytes, such as neutrophils and monocytes. LPG also dramatically inhibited IL-1beta production by another FPRL1 agonist serum amyloid A (SAA) in human phagocytes. However, LPG itself induced intracellular calcium increase and superoxide anion production in human phagocytes. Keeping in mind that phagocytes migration and IL-1beta production by FPRL1 are important for the induction of inflammatory response, our data suggest that LPG can be regarded as a useful material for the modulation of inflammatory response induced by FPRL1 activation.

A potent trypanocidal component from the fungus Lentinus strigosus inhibits trypanothione reductase and modulates PBMC proliferation

The fungus Lentinus strigosus (Pegler 1983) (Polyporaceae, basidiomycete) was selected in a screen for inhibitory activity on Trypanosoma cruzi trypanothione reductase (TR). The crude extract of L. strigosus was able to completely inhibit TR at 20 µg/ml. Two triquinane sesquiterpenoids (dihydrohypnophilin and hypnophilin), in addition to two panepoxydol derivatives (neopanepoxydol and panepoxydone), were isolated using a bioassay-guided fractionation protocol. Hypnophilin and panepoxydone displayed IC50 values of 0.8 and 38.9 µM in the TR assay, respectively, while the other two compounds were inactive. The activity of hypnophilin was confirmed in a secondary assay with the intracellular amastigote forms of T. cruzi, in which it presented an IC50 value of 2.5 µ M. Quantitative flow cytometry experiments demonstrated that hypnophilin at 4 µM also reduced the proliferation of human peripheral blood monocluear cells (PBMC) stimulated with phytohemaglutinin, without any apparent interference on the viability of lymphocytes and monocytes. As the host immune response plays a pivotal role in the adverse events triggered by antigen release during treatment with trypanocidal drugs, the ability of hypnophilin to kill the intracellular forms of T. cruzi while modulating human PBMC proliferation suggests that this terpenoid may be a promising prototype for the development of new chemotherapeutical agents for Chagas disease.

Human LZIP induces monocyte CC chemokine receptor 2 expression leading to enhancement of monocyte chemoattractant protein 1/CCL2-induced cell migration

Chemokines and chemokine receptors play a role in migration of circulating leukocytes to the region of inflammation. Human LZIP is an uncharacterized transcription factor and is known to participate in leukotactin (Lkn)-1/CCL15-induced cell migration. We investigated the role of human LZIP in expression of CC chemokine receptors (CCRs) and its involvement in monocyte migration. RNase protection analysis showed that LZIP increased mRNA expression of CCR2 and CCR1 in THP-1 cells. Surface expressions of both CCR2 and CCR1 were also increased by LZIP. Results from an electrophoretic mobility shift assay showed that LZIP binds to the C/EBP element in the CCR2 promoter. LZIP also enhanced the chemotactic activities of monocyte chemoattractant protein-1/CCL2 and Lkn-1. These results suggest that LZIP regulates expression of chemokine receptors that are involved in monocyte migration.

CD36 signaling inhibits the translation of heat shock protein 70 induced by oxidized low density lipoprotein through activation of peroxisome proliferators-activated receptor gamma

Oxidized LDL (OxLDL), a causal factor in atherosclerosis, induces the expression of heat shock proteins (Hsp) in a variety of cells. In this study, we investigated the role of CD36, an OxLDL receptor, and peroxisome proliferator-activated receptor gamma (PPAR gamma) in OxLDL-induced Hsp70 expression. Overexpression of dominant-negative forms of CD36 or knockdown of CD36 by siRNA transfection increased OxLDL-induced Hsp70 protein expression in human monocytic U937 cells, suggesting that CD36 signaling inhibits Hsp70 expression. Similar results were obtained by the inhibition of PPAR gamma activity or knockdown of PPAR gamma expression. In contrast, overexpression of CD36, which is induced by treatment of MCF-7 cells with troglitazone, decreased Hsp70 protein expression induced by OxLDL. Interestingly, activation of PPAR gamma through a synthetic ligand, ciglitazone or troglitazone, decreased the expression levels of Hsp70 protein in OxLDL-treated U937 cells. However, major changes in Hsp70 mRNA levels were not observed. Cycloheximide studies demonstrate that troglitazone attenuates Hsp70 translation but not Hsp70 protein stability. PPAR gamma siRNA transfection reversed the inhibitory effects of troglitazone on Hsp70 translation. These results suggest that CD36 signaling may inhibit stress- induced gene expression by suppressing translation via activation of PPAR gamma in monocytes. These findings reveal a new molecular basis for the anti-inflammatory effects of PPAR gamma.

The effects of fluconazole and cytokines on human mononuclear cells

Candida infections are common infections and fluconazole is one of the most frequently administered antifungal agents in their treatment. The resistance developed against antifungal agents has necessitated the improvement of new treatments. This study focuses on the investigation of the effect of fluconazole and cytokines such as interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), granulocyte-macrophage colony-stimulating factor (GM-CSF) on chemokine production and anticandidal activity of human monocytes. In the study it was observed that GM-CSF caused an increase in candidacidal activity of monocytes. Anticandidal activity of GM-CSF + IFN-gamma combination was not found to be more effective than GM-CSF or IFN-gamma alone. The presence of cytokine and fluconazole caused an increase in the levels of CCL3 and CCL4 chemokines. Accordingly, it was considered that chemokines could contribute to the efficacy of fluconazole in C. albicans infections. Besides, in order to strengthen the immune system some cytokines might be used in addition to antifungal agents for the treatment.

p38 MAPK and ERK activation by 9-cis-retinoic acid induces chemokine receptors CCR1 and CCR2 expression in human monocytic THP-1 cells

9-cis-retinoic acid (9CRA) plays an important role in the immune response; this includes cytokine production and cell migration. We have previously demonstrated that 9CRA increases expression of chemokine receptors CCR1 and CCR2 in human monocytes. To better understand how 9CRA induces CCR1 and CCR2 expression, we examined the contribution of signaling proteins in human monocytic THP-1 cells. The mRNA and surface protein up-regulation of CCR1 and CCR2 in 9CRA-stimulated cells were weakly blocked by the pretreatment of SB202190, a p38 MAPK inhibitor, and PD98059, an upstream ERK inhibitor. Activation of p38 MAPK and ERK1/2 was induced in both a time and dose-dependent manner after 9CRA stimulation. Both p38 MAPK and ERK1/2 phosphorylation peaked at 2 h after a 100 nM 9CRA treatment. 9CRA increased calcium influx and chemotactic activity in response to CCR1-dependent chemokines, Lkn-1/CCL15, MIP-1alpha/CCL3, and RANTES/CCL5, and the CCR2-specific chemokine, MCP-1/CCL2. Both SB202190 and PD98059 pretreatment diminished the increased calcium mobilization and chemotactic ability due to 9CRA. SB202190 inhibited the expression and functional activities of CCR1 and CCR2 more effectively than did PD98059. Therefore, our results demonstrate that 9CRA transduces the signal through p38 MAPK and ERK1/2 for CCR1 and CCR2 up-regulation, and may regulate the pro-inflammatory process through the p38 MAPK and ERK-dependent signaling pathways.

Effects of dengue virus infection on peripheral blood cells of mice exposed to hexavalent chromium with drinking water.

BACKGROUND & OBJECTIVE: The occupational and non-occupational exposure to hexavalent chromium Cr (VI) is common. The effect of chromium compromises the immune response of the host. Dengue virus (DV) infection causes various changes in the peripheral blood cells. It is, therefore, possible that the chromium toxicity may affect the disease process during DV infection. The present study aims to study the effects of dengue virus infection on peripheral blood cells of mice fed Cr (VI) with drinking water. METHODS: One group of mice was given ad libitum drinking water containing Cr (VI) and the other group used as the normal control mice was given plain water to drink. At the 3, 6 and 9 wk of Cr (VI) drinking, a set of mice from each group was inoculated intracerebrally (ic) with DV and studied at the 4th and 8th day post inoculation. RESULTS: It was observed that Cr (VI) drinking led to reduction in lymphocytes, haemoglobin and the haematocrit values while the granulocyte, monocyte and platelet counts were increased. On the other hand, most of the parameters were decreased following inoculation of normal mice with DV. In Cr (VI)-fed mice the effects of DV infection were minimal. The most significant finding of these experiments was that the reduction in platelet counts following inoculation with DV was markedly less in Cr (VI)-fed mice than that in DV-inoculated normal control mice. INTERPRETATION & CONCLUSION: Cr(VI) compounds have been declared as a potent occupational carcinogen. On the contrary, Cr(III) salts such as chromium polynicotinate, chromium chloride and chromium picolinate, are used as micronutrients and nutritional supplements, and have been shown to exhibit health benefits in animals and humans. Whether therapeutic doses of chromium (III) compounds may be able to prevent the DV-induced fall in platelet counts, needs to be investigated.

An overview of the effects of annexin 1 on cells involved in the inflammatory process

The concept of anti-inflammation is currently evolving with the definition of several endogenous inhibitory circuits that are important in the control of the host inflammatory response. Here we focus on one of these pathways, the annexin 1 (ANXA1) system. Originally identified as a 37 kDa glucocorticoid-inducible protein, ANXA1 has emerged over the last decade as an important endogenous modulator of inflammation. We review the pharmacological effects of ANXA1 on cell types involved in inflammation, from blood-borne leukocytes to resident cells. This review reveals that there is scope for more research, since most of the studies have so far focused on the effects of the protein and its peptido-mimetics on neutrophil recruitment and activation. However, many other cells central to inflammation, e.g. endothelial cells or mast cells, also express ANXA1: it is foreseen that a better definition of the role(s) of the endogenous protein in these cells will open the way to further pharmacological studies. We propose that a more systematic analysis of ANXA1 physio-pharmacology in cells involved in the host inflammatory reaction could aid in the design of novel anti-inflammatory therapeutics based on this endogenous mediator.

Ox-LDL suppresses PMA-induced MMP-9 expression and activity through CD36-mediated activation of PPAR-gamma

During chronic inflammatory response, mono- cytes/macrophages produce 92-kDa matrix metalloproteinase-9 (MMP-9), which may contribute to their extravasation, migration and tissue remodeling. Activation of peroxisome proliferator- activated factor receptor-gamma (PPAR-gamma) has been shown to inhibit MMP-9 activity. To evaluate whether ox-LDL, a PPAR-gamma activator, inhibits PMA-induced MMP-9 expression and activity, and if so, whether CD36 and PPAR-gamma are involved in this process, we investigated the effect of ox-LDL on MMP-9 expression and activity in PMA-activated human monocytic cell line U937. PMA-induced MMP-9 expression and activity were suppressed by the treatment with ox-LDL (50 micrigram/ml) or PPAR-gamma activators such as troglitazone (5 micrometer), ciglitazone (5 micrometer), and 15d- PGJ2 (1 micrometer) for 24 h. This ox-LDL or PPAR-gamma activator-mediated inhibition of micrometer P-9 activity was diminished by the pre-treatment of cells with a blocking antibody to CD36, or PGF2a (0.3 micrometer), which is a PPAR-gamma inhibitor, as well as overexpression of a dominant-negative form of CD36. Taken together, these results suggest that ox-LDL suppresses PMA-induced MMP-9 expression and activity through CD36-mediated activation of PPAR-gamma.