Involvement of increased expression of chemokine C-C motif chemokine 22 (CCL22)/CC chemokine receptor 4 (CCR4) in the inflammatory injury and cartilage degradation of chondrocytes.

CCL22, which could induce chondrocyte apoptosis, was identified to be overexpressed in damaged cartilage. This study was conducted with the aim of investigating the effects of CCL22 interference on chondrocyte injury. The osteoarthritis model was established by stimulating chondrocytes with LPS. The expressions of CCL22, CCR4, matrix metallopeptidase (MMP) 3, MMP9, MMP13, (a disintegrin and metalloproteinase with thrombospondin-like motifs) ADAMTS-4, collagen II and inflammatory cytokines were measured using quantitative reverse transcription PCR (RT-qPCR) and western blot. Besides, immunoprecipitation (IP) was employed to verify the binding of CCL22 and CCR4. After CCR4 was overexpressed, cell viability was observed using Cell Counting Kit-8 (CCK-8). Additionally, cell apoptosis as well as its related proteins was detected by TUNEL and western blot, respectively. ng What's more, glycosaminoglycan (GAG) level was detected using GAG kits. CCL22 and CCR4 expression increased noticeably in LPS-stimulated ATDC5 chondrocytes. CCL22 inhibition could suppress the expression of CCR4 in LPS-induced ATDC5 cells. Likewise, CCL22 inhibition could revive the activation of LPS-induced ATDC5 cells by regulating CCR4. In addition, CCL22 knockdown alleviated inflammatory response and cell apoptosis through CCR4. Furthermore, the cartilage degradation of ADTC5 cells could be relieved by CCL22 silence via regulating CCR4. CCL22/CCR4 expression was increased in osteoarthritic cartilage injury and participated in the inflammation and cartilage degradation of chondrocytes.

Functionalization of the electronic and magnetic properties of silicene by halogen atoms unilateral adsorption: a first-principles study.

Based on first-principles calculations, the structure, electronic and magnetic properties of unilateral halogenated silicene Si2X1 (X = F, Cl, Br, I) are investigated. The formation energies of all the configurations of studied Si2X1 (X = F, Cl, Br, I) are found to be lower than that in pristine silicene, which indicates the strong stability. The band structure of half-fluorinated configuration Si2F1 presents metallic property, while other unilateral halogenated silicene Si2X1 (X = Cl, Br, I) exhibits half-metallic properties. In unilateral halogenated silicene Si2X1 (X = Cl, Br, I), the unpaired electrons in unsaturated silicon atom produce the localized magnetic moment. However, due to the strong electronegativity in F atom, the half-fluorinated silicene Si2F1 is almost non-magnetic. The metallic property of Si2F1 configuration can be tuned to half-metallic by applying biaxial tensile strain from 11.95% to 13.51%. Furthermore, applying biaxial tensile strains can tune the half-metallic property of unilateral halogenated silicene Si2X1 (X = Cl, Br, I) to a semiconductor. This half-metallic property in unilateral halogenated silicene Si2X1 (X = Cl, Br, I) can be recovered and can even be tuned to metallic if continually increasing the biaxial tensile strains.