ABSTRACT
Dental pulp cells (DPCs) are promising candidates for use as transplantable cells in regenerative medicine. However, ex vivo expansion of these cells typically requires culture media containing fetal bovine serum, which may cause infection and immunological reaction following transplantation. In addition, the proliferation and differentiation of DPCs markedly depend upon serum batches. Therefore, the present study examined whether DPCs could be expanded under serum-free conditions. DPCs obtained from four donors were identified to proliferate actively in the serum-free medium, STK2, when compared with those cells in control medium (Dulbecco's modified Eagle's medium containing 10% serum). The high proliferative potential with STK2 was maintained through multiple successive culture passages. DNA microarray analyses demonstrated that the gene expression profile of DPCs grown in STK2 was similar to that of cells grown in the control medium; however, a number of genes related to cell proliferation, including placental growth factor and inhibin-ßE, were upregulated in the STK2 cultures. Following induction of osteogenesis, DPCs grown in STK2 induced alkaline phosphatase activity and calcification at higher levels compared with the control medium cultures, indicating maintenance of differentiation potential in STK2. This serum-free culture system with DPCs may have applications in further experimental studies and as a clinical strategy in regenerative medicine.
ABSTRACT
BACKGROUND: Low-level laser is being evaluated for treating rheumatoid arthritis (RA). Recently, the linear polarized infrared light (Super Lizer, SL) irradiation may also be useful for RA treatment. However, the molecular mechanism underlying the effectiveness of SL on RA is unclear. It has been IL-20 may involved in RA disease progression. AIM: To understand how SL action, we constructed the experimental model in vitro using human rheumatoid fibroblast-like synoviocyte (MH7A) and collagen induced (CIA) RA rat in vivo. We examined the effect of SL irradiation on IL-20 gene expression in MH7A and IL-20 protein production in CIA) rat joints. MATERIALS AND METHODS: MH7A was cultured and challenged with IL-1ß, then examined IL-20 and IL-20R mRNA level by DNA microarray. IL-20 protein expression was examined by immunohistochemistry using a specific antibody against rat IL-20. RESULT: Scatter plot analysis demonstrated that an increase in IL-20 gene expression by IL-1ß was reduced by SL irradiation, but IL-20R did not show a significant change. The Immunohistochemical analysis demonstrated a strong IL-20 staining in synovial membrane tissue of CIA rat joint, and SL irradiation significantly reduced the staining. DISCUSSION: Since IL-20 has been identified as an important cytokine in the pathogenesis of RA, the reduction of IL-20 expression by SL irradiation may be one of mechanisms in reduction of inflammation in RA joints by SL irradiation suggesting that SL irradiation may be useful for RA therapy.
ABSTRACT
BACKGROUND: Rheumatoid arthritis (RA) is a systemic autoimmune disorder that involves inflammation and pain of joints. Low-level laser irradiation is being evaluated for treating RA, however, the effectiveness of linear polarized near infrared light (SuperLizer; SL) irradiation is unclear. AIM: It has been reported that interleukin 6 (IL-6) plays a key role in the progression of RA. In our previous study, using DNA microarray analysis, we examined the gene expression profiling of human rheumatoid fibroblast-like synoviocyte MH7A in response to IL-1ß administration and SL irradiation. As a result, IL-6 was listed in altered gene as increased by IL-1ß and decreased by SL irradiation. MATERIAL AND METHODS: The reduction of IL-6 gene expression in MH7A by SL irradiation was confirmed by reverse transcription polymerase chain reaction (RT-PCR) and real-time PCR. Effect of SL irradiation on the RA inflammation in the collagen induced arthritis (CIA) rats was also studied by measuring temperature. IL-6 production in knee joint of rats was analyzed by immunohisto-chemistry. RESULTS: Scatter plot analysis demonstrated that an increase in IL-6 gene expression by IL-1ß was reduced by SL irradiation. The reduction of IL-6 mRNA level by SL irradiation was successfully confirmed by RT-PCR and real-time PCR. SL irradiation treated CIA rat decreased the temperature of knee joints. The immunohistochemical analysis demonstrated a strong IL-6 staining in synovial membrane tissue of CIA rat joint, and SL irradiation significantly reduced the staining. DISCUSSION: Since IL-6 has been identified to be an important proinflarnmatory cytokine in the pathogenesis of RA, the reduction of IL-6 expression is one of mechanisms in reduction of inflammation in RA joints by SL irradiation suggesting that SL irradiation may be useful for RA therapy. CONCLUSION: SL irradiation reduced IL-6 gene expression in MH7A, and reduced inflammation and IL-6 protein expression in knee joint of CIA rats.
ABSTRACT
Although recent clinical studies have shown that laser therapy acts as an anti-inflammatory effector in the treatment of some diseases, little is known about the mechanism by which it acts in rheumatoid arthritis (RA) patients. The purpose of our work was to examine how irradiation with linear polarized infrared light (LPIL) suppresses inflammatory responses in the MH7A rheumatoid fibroblast-like synoviocyte cell line. We initially confirmed the effects of two disease-modifying anti-rheumatic treatments, LPIL irradiation and dexamethasone (Dex) administration, under experimental inflammatory conditions using gene chip technology. We found that LPIL exerted a smaller effect on gene transcription than Dex; however, IL-1beta-inducible target genes such as the CXCL type chemokines IL-8, IL-1beta and IL-6 were all clearly suppressed by LPIL to the same degree as by Dex. We also found that IL-1beta-induced release of IL-8 from MH7A cells was completely blocked by pretreatment with the (IL-8) inhibitor Bay11-7085, indicating that activation of NF-kappaB signaling plays an important role in the secretion of IL-8. Although the levels of NFKB1 and RELA transcription were unaffected by IL-1beta stimulation, phosphorylation of RelA S276 was suppressed by both LPIL and Dex. Thus LPIL likely exerts its anti-inflammatory effects by inhibiting the release of the inflammatory chemokine IL-8. A fuller understanding of the anti-inflammatory mechanism of LPIL in rheumatoid synoviocytes could serve as the basis for improved treatment of RA patients in the future.