IL-27 regulates autophagy in rheumatoid arthritis fibroblast-like synoviocytes via STAT3 signaling

Geniposide augments apoptosis in fibroblast-like synoviocytes by restoring hypoxia-enhanced JNK-BNIP3-mediated autophagy

BACKGROUND

As the main effector cells of chronic inflammation and hyperplasia of synovium, fibroblast-like synoviocytes (FLSs) show abnormal proliferation and insufficient apoptosis in the hypoxic microenvironment, which is due to the increase of BNIP3-mediated autophagy. This study aimed to explore the mechanism of geniposide (GE) on hypoxia-induced hyper-proliferative FLSs with a focus on autophagy and the JNK-BNIP3 pathway.

METHODS

The dynamic changes of autophagy, apoptosis, and hypoxia-related proteins in adjuvant arthritis (AA) rats were detected by immunohistochemistry and Western blot. The proliferation, autophagy, apoptosis, and mitochondrial state of FLSs were detected by CCK-8, flow cytometry, immunofluorescence, and transmission electron microscopy, respectively. Western blot, qRT-PCR, and co-immunoprecipitation were used to detect the expression of the JNK-BNIP3 pathway.

RESULTS

The excessive accumulation of BNIP3 in the synovium of AA rats was accompanied by inhibition of apoptosis and an increase in autophagy. GE inhibited the expression of BNIP3, enhanced apoptosis, decreased autophagy, and improved chronic inflammation and hyperplasia of synovium. The amount of autophagy under different oxygen concentrations was the key to mediating the different survival rates of FLSs, and the inhibition of autophagy triggered apoptosis. GE suppressed the proliferation of FLSs and down-regulated autophagy, leading to the accumulation of ROS and the decrease of mitochondrial membrane potential, induced the increase of apoptosis, and suppressed the accumulation of BNIP3 and the hyperphosphorylation of JNK.

CONCLUSION

GE inhibited autophagy by restoring the hypoxia-induced activated JNK-BNIP3 pathway, inducing mitochondrial oxidative damage, augmented apoptosis, and decreased survival rate of FLSs.

Panlongqi tablet suppresses adjuvant-induced rheumatoid arthritis by inhibiting the inflammatory reponse in vivo and in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Panlongqi Tablet is prepared with the ancestral secret recipe provided by Mr. Wang Jiacheng, a famous specialist in orthopedics and traumatology of China. The efficacy and safety of PLQT have been supported by years of clinical practice in the treatment of joint-related conditions. Has remarkable effect for treating rheumatoid arthritis (RA) clinically. However, its mechanism is not entirely clear.

AIM OF THE STUDY

We aim to evaluate the anti-inflammatory activity of PLQT and explore its mechanism in adjuvant-induced arthritis (AA) mice and LPS-induced Human fibroblast-like synovial (HFLS) cells.

MATERIALS AND METHODS

To this end, we analyzed the active ingredients in PLQT by HPLC-MS/MS. Furthermore, the anti-RA effect of PLQT was studied through proliferation, apoptosis, foot swelling, cytokine levels, immune organ index, histopathology and related signal pathways in LPS-induced HFLS cells and AA-treated mice.

RESULTS

HPLC-MS/MS results showed that PLQT contained a variety of active compounds, such as epicatechin, imperatorin, hydroxysafflor yellow A and so on. PLQT significantly inhibited the abnormal proliferation of HFLS cells induced by LPS, promoted cell apoptosis. In AA-treated mice, PLQT alleviated RA symptoms by alleviating paw swelling, synovial hyperplasia, pannus formation, inflammatory cell infiltration, and inhibiting abnormal immune responses. The results showed that PLQT significantly decreased the expression of inflammatory mediators (IL-1β, IL-6, IL-17) in vivo and in vitro, which may be related to the regulation of PI3K/Akt, MAPK and JAK/STAT signaling pathways.

CONCLUSION

Based on serum pharmacology and in vivo pharmacology studies, PLQT may regulate RA symptoms by regulating inflammatory and immune response-related pathways, which is an effective method for the treatment of RA.

Phospholipase A2 regulates autophagy in gouty arthritis: proteomic and metabolomic studies

BACKGROUND

Acute gouty arthritis is inflammatory joint arthritis. Gouty arthritis (GA) involves multiple pathological processes. Deposition of joints by monosodium urate (MSU) crystals has been shown to play a critical role in the injury process. Due to the different effects of MSU stimulation on the joints, the exact changes in the synovial fluid are unknown. We want to explore the changes in proteins and metabolites in the joints of gouty arthritis. Regulating various functional substances in the joint can reduce inflammation and pain symptoms.

METHODS

10 patients with gouty knee arthritis and 10 normal controls were selected from clinical, surgical cases. The biological function of the metabolome was assessed by co-expression network analysis. A molecular network based on metabolomic and proteomic data was constructed to study critical molecules. The fundamental molecular changes in the relevant pathways were then verified by western blot.

RESULTS

Proteomic analysis showed that the expressions of proteases Cathepsin B, Cathepsin D, Cathepsin G, and Cathepsin S in synovial fluid patients with gouty arthritis were significantly increased. Enrichment analysis showed a positive correlation between lysosomal and clinical inflammatory cell shape changes. Untargeted metabolomic analysis revealed that lipids and lipoids accumulate, inhibit autophagic flux, and modulate inflammation and immunity in gouty arthritis patients. It was determined that the accumulation of lipid substances such as phospholipase A2 led to the imbalanced state of the autophagy-lysosome complex, and the differentially expressed metabolites of Stearoylcarnitine, Tetradecanoylcarnitine, Palmitoylcarnitine were identified (|log2 fold change|> 1.5, adjusted P value < 0.05 and variable importance in prediction (VIP) > 1.5). The autophagy-lysosomal pathway was found to be associated with gouty knee arthritis. Essential molecular alterations of multi-omics networks in gouty knee arthritis patients compared with normal controls involve acute inflammatory response, exosomes, immune responses, lysosomes, linoleic acid metabolism, and synthesis.

CONCLUSIONS

Comprehensive analysis of proteomic and untargeted metabolomics revealed protein and characteristic metabolite alterations in gouty arthritis, it mainly involves lipids and lipid like molecules, phospholipase A2 and autophagic lysosomes. This study describes the pathological characteristics, pathways, potential predictors and treatment goals of gouty knee arthritis.