Abstract: Provided are methods for characterizing microvesicles or other membranous structures. The methods involve assaying samples for microvesicles or other membranous structures, and include in certain aspects determining the presence or absence of tissue transglutaminase (tTG) and/or cross-linked fibronection (FN). The microvesicles or other membranous structures can be separated from a sample using recombinant tTG or a derivative of it, or tTG or FN binding partners. Also provided are methods for inhibiting the transfer of cargo from microvesicles which contain tTG to one or more cells. This involves administering to the individual a tTG inhibitor, such as a cell-impermeable tTG inhibitor. Also provided are compositions which contain a population of microvesicles or other membranous structures, where the population is attached to tTG or a derivative thereof, or to tTG or an FN binding partner. Kits which contain reagents and other components for carrying out the method are also provided.

Abstract: The present invention relates to a method of inhibiting beta-amyloid-induced death of neuronal cells in a subject by inhibiting human tissue transglutaminase in the subject under conditions effective to inhibit beta-amyloid-induced death of neuronal cells. Also disclosed are methods for identifying candidate compounds suitable for inhibiting beta-amyloid-induced death of neuronal cells in a subject by identifying compounds which are capable of binding to human tissue transglutaminase as candidate compounds suitable for inhibiting beta-amyloid-induced death of neuronal cells in a subject. The present invention also relates to compounds suitable for inhibiting beta-amyloid-induced death of neuronal cells in a subject, as well as methods for designing such compounds.