Angiopoietin-1 and ανß3 integrin peptide promote the therapeutic effects of L-serine in an amyotrophic lateral sclerosis/Parkinsonism dementia complex model.

Amyotrophic lateral sclerosis (ALS) is an adult disorder of neurodegeneration that manifests as the destruction of upper and lower motor neurons. Beta-N-methylamino-L-alanine (L-BMAA), an amino acid not present in proteins, was found to cause intraneuronal protein misfolding and to induce ALS/Parkinsonism dementia complex (PDC), which presents symptoms analogous to those of Alzheimer's-like dementia and Parkinsonism. L-serine suppresses the erroneous incorporation of L-BMAA into proteins in the human nervous system. In this study, angiopoietin-1, an endothelial growth factor crucial for vascular development and angiogenesis, and the integrin αvß3 binding peptide C16, which inhibits inflammatory cell infiltration, were utilized to improve the local microenvironment within the central nervous system of an ALS/PDC rodent model by minimizing inflammation. Our results revealed that L-serine application yielded better effects than C16+ angiopoietin-1 treatment alone for alleviating apoptotic and autophagic changes and improving cognition and electrophysiological dysfunction, but not for improving the inflammatory micro-environment in the central nerve system, while further advances in attenuating the functional disability and pathological impairment induced by L-BMAA could be achieved by co-treatment with C16 and angiopoietin-1 in addition to L-serine. Therefore, C16+ angiopoietin-1 could be beneficial as a supplement to promote the effects of L-serine treatment.

Integrin Alpha-9 Mediates Lymphatic Valve Formation in Corneal Lymphangiogenesis.

PURPOSE: We recently reported that corneal lymphatic vessels develop integrin alpha-9 (Itga-9)-positive valves during inflammatory lymphangiogenesis. The purpose of this study was to further investigate the role of Itga-9 in corneal lymphatic valve formation in vivo and lymphatic endothelial cell (LEC) functions in vitro. METHODS: Standard murine suture placement model was used to study the effect of Itga-9 blockade on lymphatic valve formation in vivo using Itga-9 neutralizing antibody. Whole-mount corneas were harvested for immunofluorescent microscopic analysis. Additionally, human LEC culture system was used to examine the effect of Itga-9 gene knockdown on cell functions using small interfering RNAs (siRNAs). RESULTS: Itga-9 blockade in vivo significantly reduced the number of lymphatic valves formed in the inflamed cornea. Moreover, Itga-9 gene knockdown in human LECs suppresses cell functions of proliferation, adhesion, migration, and tube formation. CONCLUSIONS: Itga-9 is critically involved in corneal lymphatic valve formation. Further investigation of the Itga-9 pathway may provide novel strategies to treat lymphatic-related diseases occurring both inside and outside the eye.