ABSTRACT
In temporomandibular disorders (TMD), pain takes place when neuropeptides stimulate synovial tissue to produce several cytokines such as interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α, which activate neurons and glia of synovial membrane at the bilaminar regions of temporomandibular joint (TMJ). It has been reported that, after neurogenic differentiation, the synovial mesenchymal stem cells (SMSCs), deriving from TMJ, possess the same cytological features as the neuronal cells. This study examined the ability of substance P (SP) and calcitonin gene-related peptide (CGRP) to stimulate SMSCs and neurogenic SMSCs secreting inflammatory cytokines during TMD, evaluated the mutual effects of inflammatory cytokines and neuropeptides and tested the analgesic effect of hyaluronic acid (HA). The levels of IL-1β, IL-6 and TNF-α in SMSCs and neurogenic SMSCs in the presence of neuropeptides were measured by ELISA. SP and CGRP produced by SMSCs and neurogenic SMSCs were determined by RT-PCR and Western blotting. The results showed that the expression of SP and CGRP was significantly enhanced in the neurogenic SMSCs in response to IL-1β, IL-6 and TNF-α, and the effect was remarkably inhibited by HA. IL-1β, IL-6 and TNF-α, in return, could be enhanced in the neurogenic SMSCs upon stimulation by SP and CGRP. Neuropeptides and inflammatory cytokines might work mutually on the TMD pain. The HA-mediated analgesic effect may be implicated in the inhibition of SP and CGRP expression in neurogenic SMSCs.
ABSTRACT
In temporomandibular disorders (TMD), pain takes place when neuropeptides stimulate synovial tissue to produce several cytokines such as interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α, which activate neurons and glia of synovial membrane at the bilaminar regions of temporomandibular joint (TMJ). It has been reported that, after neurogenic differentiation, the synovial mesenchymal stem cells (SMSCs), deriving from TMJ, possess the same cytological features as the neuronal cells. This study examined the ability of substance P (SP) and calcitonin gene-related peptide (CGRP) to stimulate SMSCs and neurogenic SMSCs secreting inflammatory cytokines during TMD, evaluated the mutual effects of inflammatory cytokines and neuropeptides and tested the analgesic effect of hyaluronic acid (HA). The levels of IL-1β, IL-6 and TNF-α in SMSCs and neurogenic SMSCs in the presence of neuropeptides were measured by ELISA. SP and CGRP produced by SMSCs and neurogenic SMSCs were determined by RT-PCR and Western blotting. The results showed that the expression of SP and CGRP was significantly enhanced in the neurogenic SMSCs in response to IL-1β, IL-6 and TNF-α, and the effect was remarkably inhibited by HA. IL-1β, IL-6 and TNF-α, in return, could be enhanced in the neurogenic SMSCs upon stimulation by SP and CGRP. Neuropeptides and inflammatory cytokines might work mutually on the TMD pain. The HA-mediated analgesic effect may be implicated in the inhibition of SP and CGRP expression in neurogenic SMSCs.
Subject(s)
Female , Humans , Male , Calcitonin Gene-Related Peptide , Cells, Cultured , Cytokines , Mesenchymal Stem Cells , Metabolism , Pathology , Substance P , Synovial Membrane , Metabolism , Pathology , Temporomandibular Joint , Metabolism , Pathology , Temporomandibular Joint Disorders , Metabolism , PathologyABSTRACT
BACKGROUND: The X-ray repair cross-complementation group 1 (XRCC1) protein plays an important role in base excision repair. AIM: To elucidate the role of XRCC1 Arg399Gln, Arg194Trp and Arg280His genotypes in esophageal cancer risk, all available studies were considered in the present meta-analysis. METHODS: Eligible studies were identified by searching several electronic databases for relevant reports published before June 2012. RESULTS: According to the inclusion criteria and exclusion criteria, a total of 21 eligible studies were included in the pooled analyses. Among the 21 studies, 18 focused on Arg399Gln polymorphism, 11 described the Arg194Trp, and 4 articles investigated on Arg280His. Our analysis suggested that there was no evidence of significant association between XRCC1 Arg399Gln polymorphism and esophageal cancer risk in any genetic model. In the stratified analysis by ethnicity for Arg399Gln polymorphism and esophageal cancer, the results showed that Arg399Gln polymorphism was not associated with esophageal cancer risk. Only 4 studies analyzed the relationship between XRCC1 Arg280His polymorphism and the risk of esophageal cancer. The Arg/His and His/His genotypes were not significantly associated with increased risk of EC. A similar negative association was maintained in dominant and recessive models. However, for XRCC1 Arg194Trp polymorphism, our study showed individuals carrying the variant genotype Trp/Trp had a significant increased risk of esophageal cancer (OR = 1.295, 95 % CI 1.053-1.591, P = 0.014). In addition, increased associations were found in recessive model (OR = 1.332, 95 % CI 1.093-1.624, P = 0.005). CONCLUSIONS: Our meta-analysis suggested that Arg194Trp Trp allele might act as a risk allele in its association with esophageal cancer.
