BACKGROUND:The effects of advanced glycation end products (AGEs) on osteoclast-induced bone resorption is controversial and the underlying mechanisms remain unclear. Most of the studies indicate that AGEs can enhance bone resorption, while some othersshowthe opposite effects.
OBJECTIVE:To investigate the effects of AGEs on osteoclast-induced inorganicmatrixdissolution and organic componentdegradation and the underlying mechanisms.
METHODS:RAW 264.7 cels were induced to generate osteoclasts,and AGEs (50-400 μg/mL) or control-bovine serum albumin (100 μg/mL) was added since the beginning of the induction. The effect of AGEs on bone resorption was evaluated by analyzing the area of resorption pits on the Osteo Assay Surface plates and the expression of cathepsin K. Furthermore, the number of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cels, nuclei per osteoclasts and the expression of integrinανβ3were detected.
RESULTS AND CONCLUSION:The area of resorption pits and expression of cathepsin K in AGEs groups were significantly decreased compared withthecontrol group, and this inhibiting effect became more obvious with the increase of AGEs concentration. TRAP staining also showed that number of TRAP-positivemultinucleated celsand nuclei per osteoclast were significantly reduced in an AGE dose-dependent manner. Quantitative PCR revealed that the expression of integrin ανβ3decreased significantly with the extension of AGEs incubation time. These data indicate that AGEs can exert inhibitory effects on organic and inorganicmatrixdegradation induced by osteoclasts. The underlying mechanism may be involved in the inhibitory effects of AGEs on directed differentiation and cel fusion of osteoclast precursor cels, and migration and adhension of osteoclasts.

BACKGROUND:Previous studies have indicated that resistin stimulates a large set of chemokines in chondrocytes that are known to be important in inflammatory joint lesions.
OBJECTIVE:To further investigate the mechanism of co-regulation roles of transcription and post-transcription in the up-regulation of two chemokine genes CCL3 and CCL4 in chondrocytes in response to resistin.
METHODS:Human chondrocytes, T/C-28a2 and ATDC5 cels were cultured. The function of resistin on the chemokine genes, and the expression of C/EBPβ, nuclear factor-κB isoforms and chondrogenic specific miRNAs were tested by qPCR. The co-regulation of C/EBPβ and nuclear factor-κB was investigated by nuclear factor-κB inhibitor (IKK-NBD) and C/EBPβ inhibitor (SB303580) treatments, and subcelular localization was detected with or without resistin stimulation.
RESULTS AND CONCLUSION:Resistin could increase the expression of chemokine genes independently. Chondrocytes reacted in a non-restrictedly cel-specific manner to resistin; C/EBPβ inhibitor, nuclear factor-κB and some chondrogenic specific miRNAs in a combinatorial manner regulated chemokine gene expression. The activity of C/EBPβ was augmented by a transient increase in activity of nuclear factor-κB, and both transcription factors acted independently on the chemokine genes, CCL3 and CCL4.

Cholangiocarcinoma is a malignant tumor originating from the bile duct epithelium, with the increasing incidence year by year. Its early symptoms are atypical and the diagnosis rate is low. Most of the patients are already in advanced stage when they are diagnosed, losing the best surgery period. Currently, the conservative treatments for unresectable extrahepatic cholangiocarcinoma include stent placement, radiofrequency ablation, radiotherapy and chemotherapy, targeted and immunotherapy and other systemic treatments. But due to the high malignancy of biliary tract tumors, the tendency to develop drug resistance and the limited population benefited from the emerging treatment modalities, we urgently need to explore new treatment strategies to break this bottleneck. As a new treatment for cholangiocarcinoma, photodynamic therapy has attracted much attention for its clinical application and therapeutic effects. In this paper, we summarize the principles of photodynamic therapy, the combination of photodynamic and other therapeutic modalities, especially the combination of photodynamic with emerging immune and targeted therapies, and describe the current hotspot directions of photodynamic therapy research at home and abroad to provide reference for clinical treatment and research.