Pyrin Domain (PYD)-containing Inflammasome in Innate Immunity

Inflammasome is a cytosolic multiprotein complex to activate caspase-1 leading to the subsequent processing of inactive pro-interleukin-1-beta (Pro-IL-1beta) into its active interleukin-1 beta (IL-1beta) in response to pathogen- or danger-associated molecular pattern. In recent years, a huge progress has been made to identify inflammasome component as a molecular platform to recruit and activate caspase-1. Nucleotide-binding oligomerization domain-like receptor (NLR) family proteins such as NLRP1, NLRP3 or interleukin-1beta-converting enzyme (ICE)-protease activating factor (IPAF) have been first characterized to form inflammasome complex to induce caspase-1 activation. More recently, non-NLR type, pyrin-domain (PYD)-containing proteins such as pyrin or absent in melanoma2 (AIM2) were also proposed to form caspase-1-activating inflammasome machinery with apoptosis-associated speck-like protein containing a CARD (ASC), an essential adaptor molecule. Inflammasome pathways were shown to be crucial for protecting host organisms against diverse pathogen infections, but accumulating evidences also suggest that excessive activation of inflammasome/caspase-1 might be related to the pathogenesis of inflammation-related diseases. Indeed, mutations in NLRP3 or pyrin are closely associated with autoinflammatory diseases such as familial Mediterranean fever (FMF) syndrome or Muckle-Wells syndrome (MWS), indicating that the regulation of caspase-1 activity by inflammasome is a central process in these hereditary inflammatory disorders. Here, recent advances on the molecular mechanism of caspase-1 activation by PYD-containing inflammasomes are summarized and discussed.

Evaluation of osteogenic activity of periosteal-derived cells treated with inflammatory cytokines

INTRODUCTION: Skeletal homeostasis is normally maintained by the stability between bone formation by osteoblasts and bone resorption by osteoclasts. However, the correlation between the inflammatory reaction and osteoblastic differentiation of cultured osteoprogenitor cells has not been fully investigated. This study examined the effects of inflammatory cytokines on the osteoblastic differentiation of cultured human periosteal-derived cells. MATERIALS AND METHODS: Periosteal-derived cells were obtained from the mandibular periosteum and introduced into the cell culture. After passage 3, the periosteal-derived cells were further cultured in an osteogenic induction Dulbecco's modified Eagle's medium (DMEM) medium containing dexamethasone, ascorbic acid, and beta-glycerophosphate. In this culture medium, tumor necrosis factor (TNF)-alpha with different concentrations (0.1, 1, and 10 ng/mL) or interleukin (IL)-1beta with different concentrations (0.01, 0.1, and 1 ng/mL) were added. RESULTS: Both TNF-alpha and IL-1beta stimulated alkaline phosphatase (ALP) expression in the periosteal-derived cells. TNF-alpha and IL-1beta increased the level of ALP expression in a dose-dependent manner. Both TNF-alpha and IL-1beta also increased the level of alizarin red S staining in a dose-dependent manner during osteoblastic differentiation of cultured human periosteal-derived cells. CONCLUSION: These results suggest that inflammatory cytokines TNF-alpha and IL-1beta can stimulate the osteoblastic activity of cultured human periosteal-derived cells.

The Central and Peripheral Production of Pro-inflammatory Cytokine, IL-1b after Immune and Stress Stimulation in Rats

Interleukin-1beta (IL-1beta), one of the pro-inflammatory cytokines, acts as an endogenous pyrogen and is an important mediator of behavioral and physiological responses to immune stimulation as well as exposure to stressors. The objective of the present study was to examine the pattern of central or peripheral IL-1beta response to lipopolysaccharide (LPS) or exposure to the foot shock stress (FS) in rats. After treatment of LPS (100microgram/kg) or exposure to the FS [ten times (0.8 mA) foot shocks for 5 sec each and 90 sec interval], body temperature and IL-1beta levels in plasma, spleen and brain were measured. Both LPS and FS stimuli elicited increased body temperature but showed different patterns of peripheral IL-1beta levels. LPS produced a widespread increase in IL-1beta levels in the plasma, spleen and brain, whereas FS produced a significant increase in IL-1beta levels only in the brain regions but not in plasma and spleen. The present study suggests that IL-1beta is, centrally or peripherally in different patterns, regulated by immune stimulation or exposure to stressors and IL-1beta plays an important role in mediating responses of sickness-like behaviors induced by immune stimuli or stressors.

The Effects of Air-borne Particulate Matters on the Alveolar Macrophages for the TNF-alpha and IL-1beta Secretion / 결핵및호흡기질환

BACKGROUND: PM is known to induce various pulmonary diseases, including asthma, cancer, fibrosis and chronic bronchitis. Despite the epidemiological evidence the pathogenesis of PM-related pulmonary diseases is unclear. METHODS: This study examined the effects of PM exposure on the secretion of TNF-alpha and IL-1beta in the cultured alveolar macrophages. The cultured primary alveolar macrophages were treated with the medium, PM (5~20 microgram/cm2), LPS (5ng/ml), and PM with LPS for 24h and 48h respectively. ELISA was used to assay the secreted TNF-alpha and IL-beta in the culture medium. Western blotting was used to identify and determine the level of proteins isolated from the culture cells. The cells cultured in the Lab-Tek(R) chamber slides were stained with immunocytochemical stains. RESULTS: PM induced TNF-alpha and IL-1beta secretion in the culturing alveolar macrophages, collected from the SPF and inflammatory rats. However, the effects were only dose-dependent in the inflammatory macrophages. When the cells were co-treated with PM and LPS, there was a significant synergistic effect compared with the LPS in the both cell types. CONCLUSION: PM might be play an important role in the induction and/or potentiation of various lung diseases by oversecretion of TNF-alpha and IL-1beta.

The Regulation of Cyclooxygenase-2 Expressionby Interleukin-1beta in WISH cells / 대한산부인과학회잡지

OBJECTIVE: To determine of the regulation of cyclooxygenase-2 (COX-2) expression by Interleukin-1beta in WISH cells. METHODS: Amnion WISH cells were incubated in media containing increasing concentrations of IL-1beta or with various inhibitors. Increased COX-2 expression was determined by Western blot analysis with anti-COX-2 antibody. Concomitant measurements of culture media PGE2 were made by an enzyme immunoassay. RESULTS: The COX-2 and prostaglandin E2 production induced by IL-1beta increased in a dose- and time-dependent manner. One of the regulating factors that induced COX-2 by IL-1beta was protein kinase C (PKC). PKC inhibitor, Ro 31-8220 was pretreated and continued treating by IL-1beta. Then, PKC inhibitor completely blocked COX-2 protein induction by IL-1beta. In contrast, COX-2 induction by IL-1beta after pretreating PKC stimulator, phobol 12-myristate 13-acetate was potentiated with synergism. Another factor in controlling COX-2 protein induction was identified as phosphatidylinositol 3-kinase (PI 3K). COX-2 protein induction by IL-1beta after pretreating PI 3K inhibitors, wortmannin and LY294002 strongly increased. This kind of result reflected that PI 3K act as negative regulator. COX-2 induction by IL-1beta was known to be regulated in not only transcription step, but also translation step after performing experiment of actinomycin and cycloheximide treatment. CONCLUSION: COX-2 protein and prostaglandin E2 production induced by IL-1beta were controlled by many factors in amnion cell. Among those factors, PKC and PI 3K have an important role, but their control mechanism act as positive and negative, respectively.