Crosstalk between PPARγ Ligands and Inflammatory-Related Pathways in Natural T-Regulatory Cells from Type 1 Diabetes Mouse Model

Dual function of activated PPARγ by ligands on tumor growth and immunotherapy

As one of the peroxisome-proliferator-activated receptors (PPARs) members, PPARγ is a ligand binding and activated nuclear hormone receptor, which is an important regulator in metabolism, proliferation, tumor progression, and immune response. Increased evidence suggests that activation of PPARγ in response to ligands inhibits multiple types of cancer proliferation, metastasis, and tumor growth and induces cell apoptosis including breast cancer, colon cancer, lung cancer, and bladder cancer. Conversely, some reports suggest that activation of PPARγ is associated with tumor growth. In addition to regulating tumor progression, PPARγ could promote or inhibit tumor immunotherapy by affecting macrophage differentiation or T cell activity. These controversial findings may be derived from cancer cell types, conditions, and ligands, since some ligands are independent of PPARγ activity. Therefore, this review discussed the dual role of PPARγ on tumor progression and immunotherapy.

PFAS and Potential Adverse Effects on Bone and Adipose Tissue Through Interactions With PPARγ

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are a widely dispersed, broad class of synthetic chemicals with diverse biological effects, including effects on adipose and bone differentiation. PFAS most commonly occur as mixtures and only rarely, if ever, as single environmental contaminants. This poses significant regulatory questions and a pronounced need for chemical risk assessments, analytical methods, and technological solutions to reduce the risk to public and environmental health. The effects of PFAS on biological systems may be complex. Each may have several molecular targets initiating multiple biochemical events leading to a number of different adverse outcomes. An exposure to mixtures or coexposures of PFAS complicates the picture further. This review illustrates how PFAS target peroxisome proliferator-activated receptors. Additionally, we describe how such activation leads to changes in cell differentiation and bone development that contributes to metabolic disorder and bone weakness. This discussion sheds light on the importance of seemingly modest outcomes observed in test animals and highlights why the most sensitive end points identified in some chemical risk assessments are significant from a public health perspective.