Acetylated Diacylglycerol 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol in Autoimmune Arthritis and Interstitial Lung Disease in SKG Mice

Deer Velvet Antler Extracts Exert Anti-Inflammatory and Anti-Arthritic Effects on Human Rheumatoid Arthritis Fibroblast-Like Synoviocytes and Distinct Mouse Arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease that causes joint deformity and disability. Deer velvet antler (DA), a traditional Chinese medicine, has been used to treat various types of arthritis for several thousands of years, but the underlying mechanisms are unknown. Herein, we investigated the anti-arthritic and anti-inflammatory effects of DA in vitro and in vivo. The ethyl acetate layer of DA ethanol extract (DA-EE-EA) was used to treat tumor necrosis factor (TNF)-[Formula: see text]-stimulated fibroblast-like synoviocyte MH7A cells, collagen-induced arthritis DBA/1 mice, and SKG mice with zymosan-induced arthritis. DA-EE-EA reduced nitric oxide production, prostaglandin E2 levels, and levels of pro-inflammatory cytokines including interleukin (IL)-1[Formula: see text], IL-6, and IL-8 in MH7A cells. DA-EE-EA also downregulated the phosphorylation of mitogen-activated protein kinase p38 and c-Jun N-terminal kinase and the translocation of nuclear factor kappa B p65. Intraperitoneal injection of DA-EE-EA for 3 weeks substantially reduced clinical arthritis scores in vivo models. Pathohistological images of the hind paws showed that DA-EE-EA reduced immune cell infiltration, synovial hyperplasia, and cartilage damage. The levels of pro-inflammatory cytokines, such as tumor necrosis factor alpha, IL-1[Formula: see text], IL-6, IL-8, IL-17A, and interferon-gamma, decreased in the hind paw homogenates of DA-EE-EA-treated mice. We also identified several potential components, such as hexadecanamide, oleamide, erucamide, and lysophosphatidylcholines, that might contribute to the anti-inflammatory effects of DA-EE-EA. In conclusion, DA-EE-EA has the potential to treat RA by regulating inflammatory responses. However, the individual components of DA-EE-EA and the underlying anti-inflammatory mechanisms need further investigation in future studies.

Pirfenidone inhibits cell fibrosis in connective tissue disease-associated interstitial lung disease by targeting the TNF-α/STAT3/KL6 pathway

Background

To explore the effect and mechanism of pirfenidone in inhibiting pulmonary fibrosis in connective tissue disease-associated interstitial lung disease (CTD-ILD).

Methods

From 2018 to 2020, 50 CTD-ILD patients were enrolled in the clinical study. Based on whether pirfenidone was used during treatment, patients were enrolled into the pirfenidone group and the control group. Pulmonary function tests were compared before and after treatment. Enzyme-linked immunosorbent assay (ELISA) was performed to detect the expression of tumor necrosis factor-α (TNF-α), signal transducer and activator of transcription 3 (STAT3), and Krebs Von den Lungen-6 (KL-6) in venous blood before and after treatment. Rat type II (RLE-6TN) lung epithelial cells were cultivated for in vitro experiments, and they were sorted into the control group, bleomycin group, pirfenidone group, TNF-α group, Stattic group, and TNF-α/Stattic combined treatment group. For the in vitro experiments, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) tests were used to evaluate cell proliferation, Reverse Transcription-Polymerase Chain Reaction(RT–PCR) was performed to detect STAT3 and KL-6 mRNA expression levels, ELISA was utilized to detect TNF-α and E-cadherin expression levels, and Western blotting (WB) was performed to determine α-smooth muscle actin (α-SMA), vimentin, TNF-α, STAT3, phosphorylated signal transducer and activator of transcription 3 (PSTAT3) and KL-6 expression.

Results

In the clinical study, the pulmonary function indices including forced expiratory volume in one second (FEV1), forced vital capacity (FVC), FEV1/FVC, peak expiratory flow (PEF) and partial pressure (PaO₂) of the patients in the study group were superior to those in the control group (P<0.05). The serum TNF-α, STAT3 and KL-6 levels in the study group were significantly lower than those in the control group (P<0.05). In the in vitro experiments, the α-SMA, vimentin, STAT3 and KL-6 levels in the treatment group were significantly lower than those in the bleomycin group (P<0.05). Compared with those in the pirfenidone group, the α-SMA, vimentin, STAT3 and KL-6 levels in the TNF-α-treated group were significantly upregulated (P<0.05). Meanwhile, cell viability was further upregulated (P<0.05), and the expression of STAT3 and KL-6 was further decreased in the Stattic-treated group (P<0.05). In the group treated with infliximab combined with Stattic, TNF-α expression was significantly increased (P<0.05), cell activity was significantly restored (P<0.05), and the STAT3, KL-6 and E-cadherin expression levels were inhibited (P<0.05).

Conclusions

Pirfenidone improved pulmonary function 1 and decreased TNF-α, STAT3, and KL-6 expression in CTD-ILD patients. Moreover, pirfenidone inhibits cell fibrosis through the TNF-α/STAT3/Mucin 1(MUC1) pathway.