The interaction between aging and protein malnutrition modulates peritoneal macrophage function: An experimental study in male mice.

Malnutrition is considered one of the most common problems in the elderly population worldwide and can significantly interfere in health evolution in these individuals, predisposing them to increased infection susceptibility. The immune response triggered by infections comprises several mechanisms, and macrophages play important roles in this response. This study aimed to evaluate mechanisms related to macrophage function in a model of protein malnutrition in the elderly. Two age groups (young: 3-5 months and elderly: 18-19 months) male C57BL/6NTac mice were subjected to protein malnutrition with a low-protein diet (2 %). The nutritional status, hemogram and number of peritoneal cells were affected by both age and nutritional status. Additionally, the spreading capacity as well as the phagocytic and fungicidal activity of peritoneal macrophages were affected by the nutritional status and age of the animal. Interestingly, the percentages of F4/80+/CD11b+ and CD86+ cells were reduced mostly in elderly animals, while the TLR-4+ population was more affected by nutritional status than by age. The production of pro-inflammatory cytokines such as TNF-α, IL-1α, and IL-6 was also influenced by nutritional status and/or by age, and malnourished animals of advanced age produced higher amounts of the anti-inflammatory cytokine IL-10. Furthermore, the phosphorylation ratio of the transcription factor NFκB (pNFκB/NFκB) was directly affected by the nutritional status, independently of age. Thus, these results allow us to conclude that aging and protein malnutrition compromise macrophage function, likely affecting their immune function, and in aged protein-malnourished animals, this impairment tends to be more pronounced.

Endothelial cells from different anatomical origin have distinct responses during SNAIL/TGF-ß2-mediated endothelial-mesenchymal transition.

BACKGROUND: Endothelial-mesenchymal transition (EndMT) is a complex process whereby differentiated endothelial cells undergo phenotypic transition to mesenchymal cells. EndMT can be stimulated by several factors and the most common are the transforming growth factor-beta (TGF-ß) and SNAIL transcription factor. Given the diversity of the vascular system, it is unclear whether endothelial cells lining different vessels are able to undergo EndMT through the same mechanisms. Here we evaluate the molecular and functional changes that occur in different types of endothelial cells following induction of EndMT by overexpression of SNAIL and TGF-ß2. RESULTS: We found that responses to induction by SNAIL are determined by cell origin and marker expression. Human coronary endothelial cells (HCAECs) showed the greatest EndMT responses evidenced by significant reciprocal changes in the expression of mesenchymal and endothelial markers, effects that were potentiated by a combination of SNAIL and TGF-ß2. Key molecular events associated with EndMT driven by SNAIL/TGF-ß2 involved extracellular-matrix remodeling and inflammation (IL-8, IL-12, IGF-1, and TREM-1 signaling). Notch signaling pathway members DLL4, NOTCH3 and NOTCH4 as well as members of the Wnt signaling pathway FZD2, FZD9, and WNT5B were altered in the combination treatment strategy, implicating Notch and Wnt signaling pathways in the induction process. CONCLUSION: Our results provide a foundation for understanding the roles of specific signaling pathways in mediating EndMT in endothelial cells from different anatomical origins.