Thromboxane A2 receptor (TP) has been shown to play important roles in multiple aspects of cancer development including regulation of tumor growth, survival and metastasis. Molecular mechanisms of TP mediated cancer cell invasion remain to be identified. TP agonist, I-BOP, significantly elevated several matrix metalloproteinases (MMPs) including MMP-1, MMP-3, MMP-9 and MMP-10 in A549 human lung adenocarcinoma cells overexpressing TPα (A549-TPα) or TPβ (A549-TPβ). Signaling pathways of I-BOP-induced MMP-1 expression were examined in further detail as a model system for MMPs induction. Signaling molecules involved in I-BOP-induced MMP-1 expression were identified by using specific inhibitors including small interfering (si)-RNAs of signaling molecules and promoter reporter assay. The results indicate that I-BOP-induced MMP-1 expression is mediated by protein kinase C (PKC), extracellular signal-regulated kinase (ERK)-activator protein-1(AP-1) and ERK-CCAAT/enhancer-binding protein β (C/EBPβ) pathways. I-BOP-induced cellular invasiveness of A549-TPα cells was blocked by, GM6001, a general inhibitor of MMPs. Knockdown of MMP-1 and MMP-9 by their respective siRNA partially reduced I-BOP-stimulated A549-TPα cells invasion suggesting that other MMPs induced by I-BOP were also involved. Furthermore, secreted MMP-1 in conditioned media from I-BOP-treated A549-TPα cells (CM-I-BOP) autocrinely induced monocyte chemoattractant protein-1 (MCP-1) expression. The induction of MCP-1 by MMP-1 in A549 cells was via activation of protease-activated receptor 2 (PAR2) instead of commonly assumed PAR1. This conclusion was reached from the following findings: (1) expression of MCP-1 induced by trypsin, a PAR2 agonist, was inhibited by a PAR2 antagonist. (2) expression of MCP-1 induced by MMP-1 and by CM-I-BOP was blocked by a PAR2 antagonist but not by other PAR antagonists; (3) expression of MCP-1 induced by MMP-1 and by CM-I-BOP was attenuated significantly by pretreatment of cells with PAR2-siRNA. Finally, MCP-1 also can be induced by direct activation of TP in a SP1 involved mechanism. CM-I-BOP enhanced MCP-1-dependent migration of RAW 264.7 macrophages. Co-culture of A549 cells with RAW 264.7 macrophages induced expression of MMPs, VEGF and MCP-1 genes, and increased the invasive potential in A549 cells. My studies provide molecular mechanisms by which TP-mediated cancer cell invasion and suggest that TP is a potential anti-cancer drug target.

Thesis (Ph.D.)--University of Central Florida, 2009. / Adviser: Kiminobu Sugaya. Includes bibliographical references (p. 45-50).

The presence of inflammation in the progression of fatty liver disease induced by fasting was determined in mink. Tumour necrosis factor alpha (TNF-?), and monocyte chemoattractant protein 1 (MCP-1) liver mRNA levels were quantified by real-time PCR. Mink fasted for 5 and 7 days had significantly higher levels of TNF-? and MCP-1 liver mRNA, compared to mink fasted for 0, 1, and 3 days. Mink fasted for 7 days, but re-fed for 28 days had the lowest mRNA levels of both TNF-?, and MCP-1 demonstrating the liver’s ability to restore homeostasis post-fasting. TNF-? mRNA levels were correlated with MCP-1 liver mRNA and liver fat percent. To confirm the physical presence of inflammation, slides stained with haematoxylin and eosin were analyzed for bile ducts resulting in no significant differences. Results indicate that elevated MCP-1 and TNF-? expression are associated with fasting induced fatty liver in mink.

Cardiovascular diseases are the number one cause of death in Western societies. Endothelial dysfunction is an early event in the pathology of atherosclerosis, which is an underlying cause in the majority of cardiovascular events. Exposure to persistent environmental pollutants, such as polychlorinated biphenyls (PCBs), is a risk factor for the development of atherosclerosis. First, we tested a hypothesis that coplanar PCBs, dioxin-like chemicals with affinity for aryl hydrocarbon receptor (AhR), can stimulate up-regulation of monocyte chemoattractant protein-1 (MCP-1), an endothelium-derived chemokine that attracts monocytes into sub-endothelial space in early stages of atherosclerosis. Coplanar PCBs 77 and 126 increased expression of MCP-1 in endothelial cells, and this effect was dependent on activation of AhR and increased levels of cytochrome P450 monoxygenases. Subsequent rise in the levels of reactive oxygen species (ROS) led to a downstream stimulation of redox-sensitive kinases and transcription factors. Lipid rafts, and particularly caveolae, are enriched in endothelial cells, and down-regulation of caveolin-1, a key structural protein of caveolae, decreases the progression of atherosclerosis. Studies using deletion of caveolin-1 in vitro and in vivo demonstrated that intact caveolae were required for up-regulation of MCP-1 and pro-inflammatory interleukin-6 (IL-6) by PCB77. Nutrition can modulate adverse outcomes of human exposure to environmental chemicals. Fish oil-derived long-chain omega-3 polyunsaturated fatty acids, such as docosahexaenoic acid (DHA, 22:6ω-3), can alleviate inflammatory responses and the risk of cardiovascular disease. Cyclopentenone metabolites produced by oxidation of DHA contribute to these protective effects. Endothelial cells were pre-treated with oxidized DHA (oxDHA), prepared by incubation of the fatty acid with a free radical generator. Subsequent up-regulation of MCP-1 by coplanar PCB77 was markedly reduced. DHA-derived cyclopentenones increased nuclear translocation and DNA binding of a transcription factor NF-E2-related factor-2 (Nrf2), as well as expression levels of its target, antioxidant enzyme NAD(P)H:quinone oxidoreductase (NQO1). This stimulation of antioxidant responses prevented ROS production and inflammatory responses induced by PCB77. These data support the concept that nutrition prevents toxicity caused by environmental pollutants; thus, nutrition and can be a sensible approach to alleviate chronic pathologies associated with these chemicals.

Background: There is need for judicious use of immunosuppression in patients with active lupus nephritis (LN), however this is guided by renal biopsy which is invasive and not freely available in most centres. Novel urinary biomarkers such as monocyte chemoattractant protein-1 (MCP-1) and tumour necrosis factor-like weak inducer of apoptosis (TWEAK) are secreted in the kidney and may be useful for predicting histological class, monitoring flares and assessing response to therapy. We assessed the utility of urinary MCP-1 (uMCP-1) and TWEAK (uTWEAK) in predicting renal histological findings, disease flares and treatment response 6 months following initiation of treatment for LN in newly biopsied patients. Methods: We recruited consenting patients with active LN confirmed on kidney biopsy. Relevant baseline demographic, biochemical and histological information was collected from the patients. ELISA methods were used to assess uMCP-1 and uTWEAK at baseline and at 6 months after completion of induction therapy. Results: There were 14 females and 6 male patients with a mean age of 29.8 ± 10.7 years, 60% were of mixed ancestry, 70% had proliferative LN. There was no association between uMCP-1 and uTWEAK and histological features (LN class, activity index, chronicity index and interstitial fibrosis). At 6 months, 6 patients were lost to follow-up and of the remaining 14, 12 (85%) attained remission (partial remission (n = 7) or complete remission (n = 5)). Both biomarkers were elevated in patients with active disease and significantly declined amongst those attaining remission, p = 0.018 and p = 0.015 respectively. However, for those not attaining remission, no association was found for both biomarkers (p >0.05). Conclusion: Our study did not show correlation between uMCP-1 and uTWEAK with histological features of LN. However, both biomarkers were elevated in patients with active disease and correlated with the remission status at the end of induction phase of treatment.

Background: There is evidence that monocyte chemoattractant protein-1 (MCP-1) levels reflect the intensity of the inflammatory response in patients with cardiogenic shock (CS) complicating acute myocardial infarction (AMI) and have a predictive value for clinical outcomes. However, little is known about the effect of mild therapeutic hypothermia (MTH) on the inflammatory response in patients with CS complicating AMI. Therefore, we conducted a biomarker study to investigate the effect of MTH on MCP-1 levels in patients with CS complicating AMI. Methods: In the randomized mild hypothermia in cardiogenic shock (SHOCK-COOL) trial, 40 patients with CS complicating AMI were enrolled and assigned to MTH (33 ◦C) for 24 h or normothermia at a 1:1 ratio. Blood samples were collected at predefined time points at the day of admission/day 1, day 2 and day 3. Differences in MCP-1 levels between and within the MTH and normothermia groups were assessed. Additionally, the association of MCP-1 levels with the risk of all-cause mortality at 30 days was analyzed. Missing data were accounted for by multiple imputation as sensitivity analyses. Results: There were differences in MCP-1 levels over time between patients in MTH and normothermia groups (P for interaction = 0.013). MCP-1 levels on day 3 were higher than on day 1 in the MTH group (day 1 vs day 3: 21.2 [interquartile range, 0.25–79.9] vs. 125.7 [interquartile range, 87.3–165.4] pg/mL; p = 0.006) and higher than in the normothermia group at day 3 (MTH 125.7 [interquartile range, 87.3–165.4] vs. normothermia 12.3 [interquartile range, 0–63.9] pg/mL; p = 0.011). Irrespective of therapy, patients with higher levels of MCP-1 at hospitalization tended to have a decreased risk of all-cause mortality at 30 days (HR, 2.61; 95% CI 0.997–6.83; p = 0.051). Conclusions: The cooling phase of MTH had no significant effect on MCP-1 levels in patients with CS complicating AMI compared to normothermic control, whereas MCP-1 levels significantly increased after rewarming. Trial registration: NCT01890317.

The successful regeneration of muscle tissue is dependent upon the infiltration of phagocytic CD14++CD16- monocytes that support the proliferation and differentiation of myogenic precursor cells. Physiologically, the magnitude of the cellular response following resistance exercise is dictated by the level of receptor expression on the plasma membrane of the monocyte, as well as the secretion of their cognate ligands from tissue resident cells. However, it remains unclear whether the innate pro-inflammatory immune response varies with different resistance training protocols, and how it may impact recovery and the muscle remodeling process. Therefore, the purpose of this investigation was to examine temporal changes in the expression of chemotactic and adhesion receptors following an acute bout of high-volume, moderate-intensity (VOL) versus high-intensity, low-volume (HVY) lower-body resistance exercise in experienced, resistance trained men. Changes in receptor expression were assessed in conjunction with plasma concentrations of MCP-1, TNF?, and cortisol. Ten resistance-trained men (90.1 ± 11.3 kg; 176.0 ± 4.9 cm; 24.7 ± 3.4 yrs; 14.1 ± 6.1% body fat) performed each resistance exercise protocol in a random, counterbalanced order. Blood samples were obtained at baseline (BL), immediately (IP), 30 minutes (30P), 1 hour (1H), 2 hours (2H), and 5 hours (5H) post-exercise. Analysis of target receptor expression on CD14++CD16- monocytes was completed at BL, IP, 1H, 2H and 5H time points via flow cytometric analysis. Plasma concentrations of myoglobin, and LDH AUC were significantly greater following HVY compared to VOL (p = 0.003 and p = 0.010 respectively). Changes in plasma TNF?, MCP-1, and expression of CCR2, CD11b, and GCR on CD14++CD16- monocytes were similar following HVY and VOL. When collapsed across groups, TNF? was significantly increased at IP, 30P, 1H and 2H post-exercise (p = 0.001 – 0.004), while MCP-1 was significantly elevated at all post-exercise time points (p = 0.002 – 0.033). CCR2 expression was significantly lower at IP, 1H, 2H and 5H post-exercise (p = 0.020 – 0.040). In contrast, CD11b receptor expression was significantly greater at 1H relative to BL (p = 0.001), while GCR expression was not significantly different from baseline at any time point. As expected, plasma cortisol concentrations were significantly higher following VOL compared to HVY (p = 0.001), although this did not appear to be related to changes in receptor expression. Plasma testosterone concentrations and TNFr1 receptor expression did not appear to be affected by resistance exercise. Our results do not support a role for cortisol in the modulation of CCR2 receptors in vivo, while the degree of muscle damage does not appear to influence plasma concentrations of TNF?, or MCP-1. It is therefore likely that both HVY and VOL protocols constitute an exercise stimulus that is sufficient enough to promote a robust pro-inflammatory response, which is similar in timing and magnitude.