Aim: TRIB1 is a pseudokinase and recent GWAS analyses have linked this gene to the control of lipid homeostasis. Analysis of full body TRIB1 knockout and a liver specific TRIB1 overexpressing mouse have demonstrated that hepatic expression of TRIB1 reduces VLDL production, plasma triglycerides and cholesterol. Additionally, TRIB1 has been shown to be necessary for the development of M2 tissue macrophages. However, the interplay between TRIB1, macrophages and hepatocytes is unexplored.

Introduction Mitogen activated protein kinase (MAPK) cascades are involved in the regulation of several cellular responses including migration or proliferation. We have shown previously that tribbles-1 (trb-1), a member of the tribbles family of adaptor/scaffold proteins controls vascular smooth muscle proliferation and chemotaxis via a direct interaction with the JNK activator kinase, MKK4. However, a regulatory role in monocyte/macrophage function for members of the tribbles family has also been reported. With the current work, we aimed to gain a better understanding of the early steps of monocyte recruitment under inflammatory conditions, and in particular, the contribution of tribbles-1 to these processes. Methods We induced experimental peritonitis in trb-1 KO and trb-1 transgenic mice, where the expression of this gene was specifically modulated in the monocyte/macrophage lineage, and their littermate controls by injecting 1ml 4% thioglycollate to the peritoneal cavity. The composition of the cells infiltrating the peritoneum was analysed at 0, 6 and 24 hours post-injection by multi-colour flow cytometry. We also measured the cytokine content of the lavage fluids via the BDTM Cytometric Bead Array (CBA). Results At 6 and 24 hours post-injection we found a significant increase in the infiltration of monocytes to the peritoneal cavity in trb-1 KO animals compared to littermate controls, while the trb-1 over-expressing monocytes refrained from entering the peritoneum. We quantified the amount of IL-1a/b, TNFa, MIP1a/b and KC in the samples and found no significant difference in the production of any of these cytokines. Conclusions Trb-1 is involved in the regulation of monocyte migration under inflammatory conditions and therefore may play a significant role in the early steps of monocyte recruitment. Via this mechanism, trb-1 may contribute to the development of chronic inflammation and atherosclerosis. Further investigations will determine whether differences in the expression of leukocyte cell adhesion molecules (CAM) or other signalling abnormalities are responsible for the altered migration pattern of trb-1 KO and trb-1 transgenic monocytes.

Introduction Cardiovascular disease such as atherosclerosis is currently the leading cause of death by noncommunicable diseases worldwide. Development of atherosclerosis which is considered a chronic inflammatory disease has been associated with a number of pro-inflammatory cytokines including interleukin-1 (IL-1). IL-1 has been associated with atherosclerotic plaque formation as well as plaque rupture. Previous reports using ApoE−/−/IL1-β−/− mice have described a significant decrease in atherosclerotic area further highlighting the importance of this apical cytokine. IL-1β is released by monocytes and macrophages following P2X7 receptor activation by ATP, however the exact mechanism by which release occurs is poorly understood. We have previously identified the GAS3/PMP22 family member, epithelial membrane protein-2 (EMP2), as a P2X7 C-terminus interacting protein. Blocking EMP2 has been shown to reduce early Chlamydia trachomatis infectivity and modify cytokine secretion; however the function of EMP2 in this role is not described. The purpose of this study was to establish the role of EMP2 in P2X7 receptor dependent IL-1β release. Methods THP1 monocytic cells were transfected with non-targeting control siRNA, siRNA specific for EMP2 or the fluorescent indicator SiGLO, using the reagent Dharmafect Duo with an optimised protocol for THP-1 cells. Transfection efficiency was determined by flow cytometry and the efficiency of the knock-down was assessed by real-time PCR. THP1 cells were then treated with PMA (500 nM) for 3 hours to promote differentiation to a more macrophage like phenotype. Differentiated THP1 cells were stimulated with 1 µg/ml of LPS with and without a P2X7 receptor antagonist (A438079 hydrochloride), followed by BzATP (300 µM, P2X7 agonist) for 20 minutes. Cell supernatants were collected and IL-1β release was measured by ELISA; cytotoxicity was determined by lactate dehydrogenase (LDH) release. Results BzATP treatment of THP1 cells significantly enhanced IL-1β release compared with LPS stimulation alone. P2X7 receptor dependent IL-1β release was almost completely inhibited by pre-treatment with the receptor antagonist. SiRNA knockdown of EMP2 was approximately 40%, as confirmed by real-time PCR, and significantly enhanced P2X7 receptor dependent IL-1β release compared with controls. There was no significant difference in LDH release following stimulation with LPS or BzATP, suggesting that the increase in IL-1β release was not due to cytotoxicity. Conclusions EMP2 contributes to the regulation of P2X7 receptor dependent IL-1β release by differentiated THP1 cells.

The primary objective of this study was to perform new, relevant information about cranial suture closure in adults. Single nucleotide polymorphisms (SNPs) in targeted genes were examined, which encode factors that play an important role in cranial suture development and maintenance. Our hypothesis was that some of these genes and polymorphisms can influence the cranial suture obliteration status in adulthood as well.

In the last few years, it has been recognized that the unbalanced regulation of survival and apoptosis of bronchial inflammatory cells is a key component in the development of asthma. Baculoviral IAP repeat containing 5 (BIRC5) (also known as survivin) is an important anti-apoptotic protein that has been implicated in many cancer types, and recent studies provide evidence for its role in controlling inflammatory disorders as well. Our aim was to investigate at both genetic and transcriptional levels if BIRC5 has an impact on asthma development. We found that induced sputum samples of patients with bronchial asthma contained elevated levels of BIRC5 mRNA compared with healthy subjects and its level was in correlation with sputum eosinophil percentages. Furthermore, in a case–control study examining single nucleotide polymorphisms (SNPs) in the BIRC5 regulatory regions, the minor alleles of rs8073903 and rs8073069 were found to be significantly associated with asthma and especially nonallergic asthma phenotypes, which associations were more prominent among women. Two marker haplotype analyses further strengthen the impact of these two polymorphisms on both asthma and non-allergic asthma. In the female cohort, rs1508147 was also significantly associated with increased risk of non-allergic asthma. Additionally, with linear regression analysis, we showed that rs9904341 was significantly correlated with both absolute and relative serum eosinophil levels. In conclusion, our results suggest that possibly by inhibition of the eosinophil apoptosis, BIRC5 might be an important regulator of the asthmatic processes and we provide some evidence that its effect might be affected by SNPs located in the gene regulatory regions.