As such, the origin and physiologic functions of these vesicles are unknown, and, their roles in

the pathology of diseases have not been elucidated. Nevertheless, the strong association between their protein cargo load and disease manifestation implicates an active role in the pathophysiology, and therefore a sentinel for disease progression and resolution. The exclusiveness of the CTB and AV binding affinities for these vesicles indicate that the lipid compositions of these 2 vesicles are different and their membrane biogenesis originates from different microdomains in the plasma membranes. As different microdomains are functionally different, a difference in the origins and functions of these vesicles could be inferred. In addition, we noted that serum is a rich source of platelet microparticles but a relatively poor source

Sirolimus manufacturer of CTB- or AV-binding vesicles, suggesting that the most of CTB- or AV-binding vesicles in the plasma were not platelet microparticles. Based on our current understanding of membrane vesicles, we speculate that because the CTB-vesicles were rich in GM1 ganglioside, they could be derived from lipid rafts and therefore, were likely to be exosomes.8 On the other hand, it is difficult to speculate on the identity of AV-vesicles as exosomes, microvesicles, ectosomes and possibly GSK1349572 nmr others have been reported to have exposed phosphatidylserines.8 In healthy cells, phosphatidylserines are mainly localized on the inner leaflet of the membrane and this asymmetry is actively maintained by ATP-dependent aminophospholipid translocase.14 In dying cells or membrane vesicles where ATP production is not sustainable, phosphotidylserines become exposed by spontaneous diffusion between the 2 membrane leaflets. Linifanib (ABT-869) We hypothesize that the absence of phosphatidylserines in CTB-vesicles could be due to the characteristic rigidity of the lipid rafts15 from which the CTB-affinity was supposedly derived. This

rigidity could restrict the diffusion of lipids and proteins in the plasma membrane and prevent spontaneous distribution of phosphatidylserines between the 2 lipid membranes. Analysis of CTB- and AV-vesicles in the plasma of preeclampsia patients and matched healthy controls revealed that they carry previously reported biomarker candidates for preeclampsia. However, the relative levels of each candidate biomarker in each of these 2 vesicles from plasma of patients and matched healthy controls were distributed into nearly all possible permutations. For example, CD105 was elevated in CTB- but AV-vesicles of PE patients, PAI-1 was elevated in both CTB- and AV-vesicles of PE patients, and CD9 was reduced in CTB-vesicles but not elevated in AV-vesicles of PE patients. This diverse permutation was further validated by a global proteomic profiling of the vesicles by mass spectrometry.