LIX/CXCL5 Protein, Mouse

CXCL5 belongs to the CXC-type chemokine family with a specific amino acid sequence of glutamic acid-leucine-arginine which is shortly named as ELR motif. The ELR motif of CXC-type chemokine family plays an important role in angiogenesis. CXCL5 is expressed by many immune cells, such as macrophages, eosinophils, as well as non-immune cells including mesothelial cells, and fibroblasts^[1][2].
Human CXCL5 shares 57% amino acid sequence identity with mouse and rat CXCL5.
CXCL5 can recruit cells, such as T/B lymphocytes and eosinophils from the immune system to the corresponding regions during immune response. Besides, it also participates in promoting the adhesion and remodeling of connective tissues. CXCL5 is highly expressed in various tumor tissues. CXCL5 can be used as a potential indicator of tumor prognosis. In tumor microenvironment (TME), CXCL5 binds to its receptors, such as CXCR2, to participate in the recruitment of immune cells and promote angiogenesis, tumor growth, and metastasis. Mesenchymal stem cells (MSCs) activated by acidic TME or TNF-α can secrete CXCL5 and other pro-inflammatory factors. Besides, cancer-associated mesothelial cells, which are generated by plasminogen activator inhibitor-1 (PAI-1), can secrete IL-8 and CXCL5 via the NF-κB signaling pathway and thereby promoting peritoneal metastasis. Adipose tissue-derived stem cells (ASCs) secrete CXCL5 which subsequently promotes tumor growth and affects the development of breast tumors^[2].
The CXCL5/CXCR2 axis recruits neutrophils, promotes angiogenesis and remodels connective tissues. In addition, CXCL5 promotes angiogenesis via activating the AKT/NF-κB/FOXD1/VEGF-A pathway in a CXCR2-dependent manner. CXCL5 plays a role in cancer cell proliferation, migration, and invasion. CXCL5 promotes the proliferation of several types of tumor cells, such as the tumor cells in prostate cancer, cervical cancer, lung cancer, hepatoblastoma, and osteosarcoma^[1][2][3].

Recombinant mouse CXCL5 protein (1 μg/50 μL; intravenously injection) injected into WT and Cxcl5^{−/− mice, the results shows that the plasma concentrations of CXCL5, CXCL1, and CXCL2 in Cxcl5−/− mice are attenuated relative to those in WT mice. CXCL5 inhibits chemokine scavenging in blood in part through binding to erythrocyte DARC[4].}

Recombinant mouse CXCL5 (300 ng/mL) blocks insulin-stimulated glucose uptake in mouse embryonic fibroblasts (MEFs). CXCL5 treatment inhibits insulin-induced Akt phosphorylation. CXCL5 blocks insulin signaling by activating the Jak2/STAT5/SOCS2 pathway^[5].