No abstract

No abstract

Accumulating data have indicated a fundamental role of eosinophils in regulating adipose tissue homeostasis. Here, we performed whole-genome RNA sequencing of the small intestinal tract, which suggested the presence of impaired lipid metabolism in eosinophil-deficient ΔdblGATA mice. ΔdblGATA mice fed a high-fat diet (HFD) showed reduced body fat mass, impaired enlargement of adipocytes, decreased expression of adipogenic genes, and developed glucose intolerance. HFD induced accumulation of eosinophils in the perigonadal white adipose tissue. Concordantly, adipocyte-differentiated 3T3-L1 cells promoted the migration of eosinophils through the expression of CCL11 (eotaxin-1) and likely promoted their survival through the expression of interleukin (IL)-3, IL-5, and granulocyte-macrophage colony-stimulating factor. HFD-fed ΔdblGATA mice showed increased infiltration of macrophages, CD4+ T-cells, and B-cells, increased expression of interferon-γ, and decreased expression of IL-4 and IL-13 in white adipose tissue. Interferon-γ treatment significantly decreased lipid deposition in adipocyte-differentiated 3T3-L1 cells, while IL-4 treatment promoted lipid accumulation. Notably, HFD-fed ΔdblGATA mice showed increased lipid storage in the liver as compared with wild-type mice. We propose that obesity promotes the infiltration of eosinophils into adipose tissue that subsequently contribute to the metabolic homeostasis by promoting adipocyte maturation.

Leucine-rich glioma inactivated 3 (LGI3) is a secreted protein that belongs to LGI/epitempin family. LGI3 is highly expressed in brain in a transcriptionally and developmentally regulated manner. Here we found that LGI3 induced neurite outgrowth in Neuro-2a cells and dorsal root ganglia explants. LGI3 treatment or overexpression increased neurite outgrowth and knockdown of LGI3 by siRNA had opposite effect. LGI3 treatment increased phosphorylation of Akt and a 125-kDa protein. Immunoprecipitation identified the 125-kDa protein as focal adhesion kinase (FAK). LGI3 overexpression increased phospho-Akt, phospho-FAK and FAK protein. Inhibition of Akt activation by PI3 kinase inhibitor attenuated LGI3-induced FAK phosphorylation and neurite outgrowth. Taken together, we propose that LGI3 is a neuritogenic factor whose signaling pathway involves Akt-mediated FAK activation.

No abstract