Gubi Zhitong formula alleviates osteoarthritis in vitro and in vivo via regulating BNIP3L-mediated mitophagy.

BACKGROUND: Osteoarthritis (OA) is characterized by degeneration of articular cartilage, leading to joint pain and dysfunction. Gubi Zhitong formula (GBZTF), a traditional Chinese medicine formula, has been used in the clinical treatment of OA for decades, demonstrating definite efficacy. However, its mechanism of action remains unclear, hindering its further application. METHODS: The ingredients of GBZTF were analyzed and performed with liquid chromatography-mass spectrometry (LC-MS). 6 weeks old SD rats were underwent running exercise (25 m/min, 80 min, 0°) to construct OA model with cartilage wear and tear. It was estimated by Micro-CT, Gait Analysis, Histological Stain. RNA-seq technology was performed with OA Rats' cartilage, and primary chondrocytes induced by IL-1ß (mimics OA chondrocytes) were utilized to evaluated and investigated the mechanism of how GBZTF protected OA cartilage from being damaged with some functional experiments. RESULTS: A total of 1006 compounds were identified under positive and negative ion modes by LC-MS. Then, we assessed the function of GBZTF through in vitro and vivo. It was found GBZTF could significantly up-regulate OA rats' limb coordination and weight-bearing capacity, and reduce the surface and sub-chondral bone erosions of OA joints, and protect cartilage from being destroyed by inflammatory factors (iNOS, IL-6, IL-1ß, TNF- α, MMP13, ADAMTS5), and promote OA chondrocytes proliferation and increase the S phage of cell cycle. In terms of mechanism, RNA-seq analysis of cartilage tissues revealed 1,778 and 3,824 differentially expressed genes (DEGs) in model vs control group and GBZTF vs model group, respectively. The mitophagy pathway was most significantly enriched in these DEGs. Further results of subunits of OA chondrocytes confirmed that GBZTF could alleviate OA-associated inflammation and cartilage damage through modulation BCL2 interacting protein 3-like (BNIP3L)-mediated mitophagy. CONCLUSION: The therapeutic effectiveness of GBZTF on OA were first time verified in vivo and vitro through functional experiments and RNA-seq, which provides convincing evidence to support the molecular mechanisms of GBZTF as a promising therapeutic decoction for OA.

Immune factors have a complex causal regulation on pulmonary fibrosis: Insights from a two-sample Mendelian randomization analysis.

Pulmonary fibrosis is a chronic, progressive lung disease characterized by excessive scarring of lung tissue, and its pathophysiological mechanisms have not been fully elucidated. Immune cells play a key role in many diseases, and this study aims to explore the causal link between immune cell characteristics and pulmonary fibrosis using Mendelian randomization. Utilizing the public GWAS database Open GWAS, this study collected whole-genome association study datasets of peripheral blood immune phenotypes and summary data of GWAS related to pulmonary fibrosis. Through Mendelian randomization (MR) analysis, we identified single nucleotide polymorphisms (SNPs) significantly associated with immune traits as instrumental variables. After pleiotropy and heterogeneity tests, causal effects were assessed using methods such as inverse-variance weighted (IVW), weighted median, and MR-Egger. Comprehensive MR analysis indicated a significant causal relationship between various immune cell types, including regulatory T cells (Tregs), natural killer (NK) cells, and specific monocyte subgroups, with the risk of pulmonary fibrosis. Specifically, phenotypes such as Activated & resting Treg %CD4+, CCR2-positive monocytes, and CD16-CD56 positive NK cells were associated with a reduced risk of pulmonary fibrosis. In contrast, CD8 + T cell subgroups were associated with an increased risk. This study provides evidence of a causal relationship between immune cell characteristics and pulmonary fibrosis, highlighting the protective role of regulatory T cells and specific NK cell subgroups, as well as the potential harm of CD8 + T cell subgroups. These findings offer new insights into the immunoregulatory mechanisms of pulmonary fibrosis and the development of novel therapeutic strategies.