More blood in the brain evidence.
http://www.nationalmssociety.org/news/n ... px?nid=410
Progressive MS and KLK enzymes (Dr. Scarisbrick’s team): Understanding the processes that lead to tissue damage in MS is crucial to feed parallel efforts to protect and repair the brain and spinal cord. Dr. Scarisbrick previously found elevated levels of “KLK6” (a newly identified member of the kallikrein enzyme family) in areas of damage found in tissue samples from people with MS. Now, in a follow-up study, the group has studied the levels of KLK6 and other kallikreins in blood samples taken from 35 people with different clinical courses of MS and 62 controls without MS.
The results show that KLK1 and KLK6 were elevated in people with MS, with the highest levels appearing in people with secondary-progressive MS (a course of MS that initially is relapsing-remitting and then becomes progressive, with or without occasional relapses and minor remissions).
The team also exposed nerve cells isolated from mice to KLK1 or KLK6 in the laboratory, and found that the enzymes promoted nerve cell loss. Dr. Scarisbrick is continuing to study the role of these enzymes in nerve fiber injury and hopes to find a way to target them with therapeutic strategies for people with progressive MS.
Kallikrein-binding protein inhibits retinal neovascularization and decreases vascular leakage
Aims/hypothesis. Kallikrein-binding protein (KBP) is a serine proteinase inhibitor (serpin). It specifically binds to tissue kallikrein and inhibits kallikrein activity. Our study was designed to test its effects on retinal neovascularization and vascular permeability.
Methods. Endothelial cell proliferation was determined by [3H] thymidine incorporation assay and apoptosis quantified by Annexin V staining and flow cytometry. Effect on retinal neovascularization was determined by fluorescein angiography and count of pre-retinal vascular cells in an oxygen-induced retinopathy (OIR) model. Vascular permeability was assayed by the Evans blue method. Vascular endothelial growth factor (VEGF) was measured by Western blot analysis and ELISA.
Results. Kallikrein-binding protein specifically inhibited proliferation and induced apoptosis in retinal capillary endothelial cells. Intravitreal injection of KBP inhibited retinal neovascularization in an OIR model. Moreover, KBP decreased vascular leakage in the retina, iris and choroid in rats with OIR. Blockade of kinin receptors by specific antagonists showed significantly weaker inhibition of endothelial cells, when compared to that of KBP, suggesting that the anti-angiogenic activity of KBP is not through inhibiting kallikrein activity or kinin production. KBP competed with 125I-VEGF for binding to endothelial cells and down-regulated VEGF production in endothelial cells and in the retina of the OIR rat model.
Conclusion/interpretation. Kallikrein-binding protein is a multi-functional serpin, and its vascular activities are independent of its interactions with the kallikrein-kinin system. Inhibition of VEGF binding to its receptors and down-regulation of VEGF expression could represent a mechanism for the vascular activities of KBP.