PBMC-mediated modulation of macrophage polarization in RAW264.7 cells through STAT1/STAT6 signaling cascades.

Peripheral blood mononuclear cells (PBMC), sourced autologously, offer numerous advantages when procured: easier acquisition process, no in vitro amplification needed, decreased intervention and overall increased acceptability make PBMC an attractive candidate for cell therapy treatment. However, the exact mechanism by which PBMC treat diseases remains poorly understood. Immune imbalance is the pathological basis of many diseases, with macrophages playing a crucial role in this process. However, research on the role and mechanisms of PBMC in regulating macrophages remains scarce. This study employed an in vitro co-culture model of PBMC and RAW264.7 macrophages to explore the role and mechanisms of PBMC in regulating macrophages. The results showed that the co-culturing led to decreased expression of inflammatory cytokines and increased expression of anti-inflammatory cytokines in RAW264.7 or in the culture supernatant. Additionally, the pro-inflammatory, tissue matrix-degrading M1 macrophages decreased, while the anti-inflammatory, matrix-synthesizing, regenerative M2 macrophages increased in both RAW264.7 and monocytes within PBMC. Moreover, co-cultured macrophages exhibited a significantly decreased p-STAT1/STAT1 ratio, while the p-STAT6/STAT6 ratio significantly increased. This suggests that PBMC may inhibit M1 macrophage polarization by blocking STAT1 signaling cascades and may promote M2 macrophage polarization through the activation of STAT6 signaling cascades. Overall, this study sheds light on the role and mechanism of PBMC in regulating macrophages. Moreover, it was found that monocytes within co-cultured PBMC differentiated into M2 macrophages in the presence of macrophages. This finding provides experimental evidence for the use of PBMC in treating inflammatory diseases, especially macrophage-depleting inflammatory diseases such as osteoarthritis.

Tandem Mass Tag-Based Proteomic Analysis of Normal and Degenerated Human Intervertebral Discs.

Background: Intervertebral disc degeneration (IVDD) is the main cause of low back pain (LBP), but the specific regulatory factors, pathways and specific molecular mechanisms remain unclear. Methods: We identified and quantitatively analyzed Pfirrmann Grade II (n=3) and Pfirrmann Grade IV (n=3) pulposus samples via MRI. The differential abundance of proteins in the samples was determined and quantitatively analyzed by relative and absolute quantitative analysis of the isotope marker levels combined with the liquid chromatography-tandem mass spectrometry (LC‒MSMS/MS). Results: A total of 70 proteins (30 significantly increased proteins (> 1.2-fold change) and 40 significantly decreased proteins (< 0.8-fold change)) showed different levels among the groups. Kyoto Encyclopedia of Genes and Genomes and Gene Ontology (GO) enrichment analyses and Western blot analysis showed that CYCS, RAC1, and PSMD14 may play important roles in IVDD and that Epstein‒Barr virus infection, viral myocarditis, colorectal cancer, nonalcoholic fatty liver disease (NAFLD) and amyotrophic lateral sclerosis (ALS) are the main pathways involved in IVDD. Conclusion: CYCS, RAC1 and PSMD14 may play important roles in IVDD, and Epstein‒Barr virus infection, viral myocarditis, colorectal cancer, NAFLD and ALS may be the main pathways involved in IVDD.