Blockade of Proteinase-Activated Receptor 2 (PAR2) Attenuates Neuroinflammation in Experimental Autoimmune Encephalomyelitis.

Proteinase-activated receptor-2 (PAR2), which modulates inflammatory responses, is elevated in the central nervous system in multiple sclerosis (MS) and in its murine model, experimental autoimmune encephalomyelitis (EAE). In PAR2-null mice, disease severity of EAE is markedly diminished. We therefore tested whether inhibiting PAR2 activation in vivo might be a viable strategy for the treatment of MS. Using the EAE model, we show that a PAR2 antagonist, the pepducin palmitoyl-RSSAMDENSEKKRKSAIK-amide (P2pal-18S), attenuates EAE progression by affecting immune cell function. P2pal-18S treatment markedly diminishes disease severity and reduces demyelination, as well as the infiltration of T-cells and macrophages into the central nervous system. Moreover, P2pal-18S decreases granulocyte-macrophage colony-stimulating factor (GM-CSF) production and T-cell activation in cultured splenocytes and prevents macrophage polarization in vitro. We conclude that PAR2 plays a key role in regulating neuroinflammation in EAE and that PAR2 antagonists represent promising therapeutic agents for treating MS and other neuroinflammatory diseases. SIGNIFICANCE STATEMENT: Proteinase-activated receptor-2 modulates inflammatory responses and is increased in multiple sclerosis lesions. We show that the proteinase-activated receptor-2 antagonist palmitoyl-RSSAMDENSEKKRKSAIK-amide reduces disease in the murine experimental autoimmune encephalomyelitis model of multiple sclerosis by inhibiting T-cell and macrophage activation and infiltration into the central nervous system, making it a potential treatment for multiple sclerosis.

Microenvironment proteinases, proteinase-activated receptor regulation, cancer and inflammation.

We propose that in the microenvironment of inflammatory tissues, including tumours, extracellular proteinases can modulate cell signalling in part by regulating proteinase-activated receptors (PARs). We have been exploring this mechanism in a variety of inflammation and tumour-related settings that include tumour-derived cultured cells from prostate and bladder cancer, as well as immune inflammatory cells that are involved in the pathology of inflammatory diseases including multiple sclerosis. Our work showed that proteinase signalling via the PARs affects prostate and bladder cancer-derived tumour cell behaviour and can regulate calcium signalling in human T-cell and macrophage-related inflammatory cells as well as in murine splenocytes. Further, we found that the tumour-derived prostate cancer cells and immune-related cells (Jurkat, THP1, mouse splenocytes) can produce PAR-regulating proteinases (including kallikreins: kallikrein-related peptidases), that can control tissue function by both a paracrine and autocrine mechanism. We suggest that this PAR-driven signalling process involving secreted microenvironment proteinases can play a key role in cancer and inflammatory diseases including multiple sclerosis.

HLA-B*1502 in Iranian Children with Anticonvulsant Drugs-Induced Skin Reactions.

OBJECTIVE: Anticonvulsant drugs can cause various forms of skin drug reactions, ranging from exanthema to severe blistering reactions. An association between HLA-B*1502 allele and severe skin reactions have been reported. MATERIALS & METHODS: Fifteen patients with severe skin reactions following treatment with anticonvulsant drugs (Carbamazepine, lamotrigine, phenobarbital, primidone) and 15 controls (age-matched epileptic patients taking similar anticonvulsants without drug eruption) were included. They were referred to Mofid Children's Hospital in Tehran, Iran, between Jan 2012 to Jan 2014. Genomic DNA was extracted from peripheral blood of all patients and HLA- B*1502 genotype was detected by real-time PCR. RESULTS: None of the patients was positive for HLA- B*1502, but two patients in control group had positive HLA- B*1502. CONCLUSION: The HLA- B*1502 is not correlated with severe anticonvulsant drugs -induced skin reactions in Iranian children.

The Biology of ß-D-mannuronic acid (M2000) on Human Dendritic Cell Based on MicroRNA-155 and MicroRNA-221.

BACKGROUND: The aim of this study was to evaluate the effect of ß-Dmannuronic acid (M2000) on related miRNAs to dendritic cells (DCs) differentiation. DC-based immunosuppressive drugs can suppress the progression of autoimmune diseases, however, their notable side effects in increasing the risk of infectious diseases and cancers should be considered. The ß-D-mannuronic acid, as a novel non-steroidal anti-inflammatory agent, has been tested in various experimental models. METHOD: The effect of M2000 on expression of miRNA-155 and miRNA-221 was examined. To investigate how M2000 affects differentiation of human dendritic DCs in a defined inflammatory environment, human peripheral blood mononuclear cells were isolated from healthy blood and the monocytes were purified using anti-CD14 microbeads. The so isolated monocytes were subsequently incubated in the presence of M2000 in two different doses (3 and 6 mMol/well) adding granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4 for inducing monocytes to immature DC and lipopolysaccharide for running DC differentiation. The expression of miRNA-155 and miRNA-221 were examined with Real Time PCR. RESULTS: The results demonstrate that M2000 has no significant side effect on expression of miR-155 and miR-221 in both immature DC and mature DC process in vitro. CONCLUSION: Our findings show that ß-D-mannuronic acid is a safe agent which has no adverse effect on regulatory miRNA-155 and miRNA-221 in dendritic cells.

Study of the tumor microenvironment during breast cancer progression.

BACKGROUND: Different cells and mediators in the tumor microenvironment play important roles in the progression of breast cancer. The aim of this study was to determine the composition of the microenvironment during tumor progression in order to discover new related biomarkers and potentials for targeted therapy. METHODS: In this study, breast cancer biopsies from four different stages, and control breast biopsies were collected. Then, the mRNA expression of several markers related to different CD4+ T cell subsets including regulatory T cells (Treg), T helper (Th) type 1, 2 and 17 were determined. In addition, we investigated the expression of two inflammatory cytokines (TNF-α and IL-6) and inflammatory mediators including FASL, IDO, SOCS1, VEGF, and CCR7. RESULTS: The results showed that the expression of Th1 and Th17 genes was decreased in tumor tissues compared to control tissues. In addition, we found that the gene expression related to these two cell subsets decreased during cancer progression. Moreover, the expression level of TNF-α increased with tumor progression. CONCLUSION: We conclude that the expression of genes related to immune response and inflammation is different between tumor tissues and control tissues. In addition, this difference was perpetuated through the different stages of cancer.

MicroRNAs in rheumatoid arthritis.

The role of genetic and epigenetic factors in the development of rheumatic diseases has been an interesting field of research over the past decades all around the world. Research on the role of microRNAs (miRNAs) in rheumatoid arthritis (RA) has been active and ongoing, and investigations have attempted to use miRNAs as biomarkers in disease diagnosis, prognosis, and treatment. This review focuses on experimental researches in the field of miRNAs and RA to present the data available up to this date and includes researches searched by keywords "microRNA" and "rheumatoid arthritis" in PubMed from 2008 to January 2015. All references were also searched for related papers. miRNAs are shown to act as proinflammatory or anti-inflammatory agents in diverse cell types, and their role seems to be regulatory in most instances. Researchers have evaluated miRNAs in patients compared to controls or have investigated their role by overexpressing or silencing them. Multiple targets have been identified in vivo, in vitro, or in silico, and the researches still continue to show their efficacy in clinical settings.