Acetylcholinesterase distribution in subpopulations of murine thymocyte

Abstract

The presence of acetylcholinesterase has been detected in the thymus of several species both biochemically and histochemically. In this study we have investigated the molecular forms and the level of this enzyme in separate compartments of the murine thymus and in different thymocyte subpopulations. Similar levels of acetylcholinesterase activity are present both in thymocytes and in the stromal component. Sucrose density gradient analysis revealed the presence of a single molecular form of about 5 S, presumably a dimeric form. Moreover the results demonstrate a preferential association of AChE with mature thymocyte subsets (Peanut Agglutinin negative and Corticoresistant). This finding correlates with the preferential sensitivity of these cells to cholinergic drugs and supports the hypothesis that acetylcholinesterase modulates the cholinergic effects on thymocytes.

Muscular dystrophy by merosin deficiency decreases acetylcholinesterase activity in thymus of Lama2dy mice

“…Our data do not support the exclusive presence of AChE in the gland (Rossi et al . 1991), the discrepancy being explained by the improved resolution of and forms in sucrose gradients with 0.5–1% TX‐100 (present work) than in those containing 0.1% TX‐100 (Rossi et al . 1991).…”

“…Sedimentation analyses and exposure to PIPLC allowed us to identify in thymus abundant GPI‐anchored AChE dimers (, 64%), fewer monomers (, 19%), and a few hydrophilic tetramers (, 9%) and monomers (, 8%). The results extend previous data concerning the molecular composition of AChE in mouse thymus and clarify the controversy relating to the presence or otherwise of species (Bulloch and Lucito 1988; Rossi et al . 1991).…”

“…1994) express AChE mRNAs, and rat thymus (Cavallotti et al . 2000a), mouse thymocytes (Rossi et al . 1991) and spleen (Nieto‐Cerón et al .…”

Choline acetyltransferase activity in murine thymus

“…In a previous study, we reported that murine thymocytes exhibit a different responsiveness when incubated in vitro with cholinergic agonists, which induce selective proliferation of the mature peanut agglutinin-0 1992 Wiley-Liss, Inc. negative (PNA-) thymocyte subset (Rossi et al, 1989). The significantly higher levels of the enzyme acetylcholinesterase (AChE), which is responsible for the hydrolysis of ACh, in this subset of cells constitutes an interesting coincidence (Rossi et al, 1991). Taken together, these results suggest the possibility of a differential regulatory role for ACh on thymocyte subpopulations and have led us to investigate, by means of a radiochemical assay, the presence in the thymus gland of choline acetyltransferase (ChAT), the key enzyme in the synthesis of ACh.…”

PNA Lectin-Based Separation of Thymocytes into Mature and Immature Subpopulations: CD4–8- Double Negative Cells Display Characteristics of PNAloMature Thymocytes

“…consistent witb earlier reports involving pre-and postnatal exposure of mice to TCDD (22.24.28-30). In addition, a small but significant increase in the percentage of PNAlo thymocytes was present in TCDD-treated mice.DISCUSSIONDifferential PNA binding properties of mature versus immature thymocytes have made PNA a convenient and a popular tool for separating mature medullary thymocytes from immature cortical precursor cells (1.4-5 [26][27][28][29]…”