In vitro study of inhibitory millimeter wave treatment effects on the TNF-α-induced NF-κB signal transduction pathway

Abstract

Abstract. Abnormal activation of the nuclear factor-κB (NF-κB) in chondrocytes initiates the transcription of inflammatory mediators, promotes their generation and release, and amplifies initial inflammatory signals. This results in the release of chondral matrix-degrading enzymes and accelerates the degeneration of articular cartilage. As a non-pharmaceutical and non-invasive physical therapy regimen, millimeter wave treatment has been successfully used for the treatment of osteoarthritis. In this study, chondrocytes were derived from the cartilages of knee joints of 4-week-old male Sprague-Dawley rats and were mechanically digested by collagenase type II treatment for further culture in vitro. The third-passage chondrocytes were stained with toluidine blue and treated with a gradient of tumor necrosis factor-· (TNF-·) for various times. Chondrocytic activity was measured by MTT assay, and the apoptotic rate of the chondrocytes was determined with Hocehst 33342 staining to identify effective treatment concentrations and durations and to establish an apoptosis model for the chondrocytes in response to TNF-·. Using this model, the chondrocytes were randomly divided to receive millimeter wave treatment for various times. The apoptotic rate of the chondrocytes was measured by Annexin V-FITC staining and the protein expression levels of RIP, TAK1, IκB kinase (IKK)-ß, IκB-· and NF-κB, were determined by Western blotting. Chondrocytic structure was examined by transmission electronic microscopy. The apoptotic rates were significantly lower at 4 and 8 h of treatment than at 0 and 2 h. The expression levels of RIP, TAK1, IKK-ß and NF-κB were also significantly lower at 4 and 8 h than at 0 and 2 h, whereas that of IκB-· was significantly higher at 4 and 8 h than at 0 and 2 h. Therefore, we can conclude that millimeter wave treatment can inhibit the activation of the TNF-·-mediated NF-κB signal transduction pathway through the down-regulation of RIP, TAK1, IKK-ß and NF-κB, and the up-regulation of IκB-·, in chondrocytes.

Millimeter Wave Treatment Inhibits Apoptosis of Chondrocytes via Regulation Dynamic Equilibrium of Intracellular Free Ca2+

“…Our preliminary work demonstrated that MW inhibits the activation of the TNF- α -mediated NF- κ B signal transduction pathway [ 13 ]. To further discover the millimeter wave's mechanism of action, we used TNF- α to induce apoptosis.…”

Millimeter wave treatment promotes chondrocyte proliferation via G1/S cell cycle transition

“…Millimeter wave is a high-frequency electromagnetic wave at a wavelength from 1-10 mm and a frequency of 300 million cycles/sec (300 MHz) to 300 billion cycles/second (300 GHz) (10,11). The millimeter waves within living organisms generate 0.5x10 10 -3x10 12 coherent oscillations during metabolism, which can be absorbed by biological tissues through resonance to produce a non-thermal biological effect (12).…”

Chemopreventive potential of alpha lipoic acid in the treatment of colon and cervix cancer cell lines

“…On several in vitro models have shown that inhibition and reduced activity of NF-κB is associated with decreasing of MTT reduction, which shows that there is cytotoxic, apotototic and/or antiproliferative effect (30,31). Our treatments have generally shown that decrease of NF-κB activity went along with the decline of MTT test values.…”