ABSTRACT
ATP (Adenosine triphosphate) is an important endogenous damage-associated molecular pattern (DAMP). P2X7R is an ATP-gated cation channel. ATP-P2X7R plays a vital role in the pathophysiology of many diseases because P2X7R is distributed on various immune cells. ATP-P2X7R signal transduction pathway has been implicated to participate in the body's im-mune defense against pathogens. This paper reviews the recent progress regarding ATP-P2X7R and its effects on parasitic diseas-es.
ABSTRACT
STUDY DESIGN: Experimental investigation in vitro. OBJECTIVES: To evaluate the relationship between the degeneration of intervertebral disc cells, and low back pain induced by degeneration of intervertebral disc cells and increases in use of proinflammatory mediators via nicotine stimulation. SUMMARY OF LITERATURE REVIEW: Smoking is a leading cause of degeneration of intervertebral disc cells and low back pain. According to the existing literature, nicotine, one of the main ingredients in cigarettes, causes the degeneration of intervertebral disk cells including decrease of glycoprotein through generation of carboxy-hemoglobin, vasoconstriction, and disability of fibrinolysis and changes of metabolism of nucleus pulposus cells. MATERIALS AND METHODS: Annulus fibrosus of intervertebral disc and knee joint cartilage were collected from pigs; these cells were acquired by gradual enzyme decomposition. Using Trypan blue, concentration and survival rate of cells were examined; cells were inserted on alginate beads for tertiary cultivation. Nicotine was then applied at 0, 50, 100, 200 and 300 nM, respectively, and the samples were cultivated for three, six and nine days, respectively. After collecting culture fluid, it was measured for interleukin(IL)-1beta, IL-6 and IL-8 with the ELISA Test. DNA of cells used for cultivation was quantitated and the amount of the resulting proinflammatory mediator was normalized. The results were then compared with the result of same study on cartilage of porcine knee joints. RESULTS: For changes of the inflammatory mediator based on the concentration of nicotine, in nicotine stimulation with low concentration of 50 nM and the control group, there was no significant change, while transient increases of inflammatory mediator showed in nicotine stimulation with concentrations of 100, 200 nM, respectively. There was not a significant increase of IL-1beta observed in all nicotine stimulation groups; these were the same results in porcine cartilage study. The level of IL-6 in 200, 300 nM nicotine concentration showed significant increases, respectively. The level of IL-8 in high dose nicotine stimulation groups also showed significant increases of DNA on the sixth day. And in porcine cartilage study group, significant changes were observed in 200, 300 nM, but the absolute value was lower than that of annulus fibrous cells group. CONCLUSION: Inflammatory mediators such as IL-6 and IL-8 increased as the result of tertiary cultivation of annulus fibrosus cells of porcine intervertebral disk and nicotine stimulation. It is believed that the cells of the disc annulus are more sensitive than articular chondrocytes to nicotine stimulation. This may be the focus of future long-term studies effects of nicotine other inflammatory cytokines.