ARP, A Peptide Derived from the Stress-Associated Acetylcholinesterase Variant, Has Hematopoietic Growth Promoting Activities

Abstract

Background: Psychological stress induces rapid and longlasting changes in blood cell composition, implying the existence of stress-induced factors that modulate hematopoiesis. Here we report the involvement of the stressassociated "readthrough" acetylcholinesterase (AChE-R) variant, and its 26 amino acid C-terminal domain (ARP) in hematopoietic stress responses. Materials and Methods:We studied the effects of stress, cortisol, antisense oligonucleotides to AChE, and synthetic ARP on peripheral blood cell composition and clonogenic progenitor status in mice under normal and stress conditions, and on purified CD34 1 cells of human origin. We employed in situ hybridization and immunocytochemical staining to monitor gene expression, and 5-bromo-2-deoxyuridine (BrdU), primary liquid cultures, and clonogenic progenitor assays to correlate AChE-R and The first two authors contributed equally to this investigation. ARP with proliferation and differentiation of hematopoietic progenitors. Results: We identified two putative glucocorticoid response elements in the human ACHE gene encoding AChE. In human CD34 1 hematopoietic progenitor cells, cortisol elevated AChE-R mRNA levels and promoted hematopoietic expansion. In mice, a small peptide crossreacting with anti-ARP antiserum appeared in serum following forced swim stress. Ex vivo, ARP was more effective than cortisol and equally as effective as stem cell factor in promoting expansion and differentiation of early hematopoietic progenitor cells into myeloid and megakaryocyte lineages. Conclusions: Our findings attribute a role to AChE-R and ARP in hematopoietic homeostasis following stress, and suggest the use of ARP in clinical settings where ex vivo expansion of progenitor cells is required.

Hematology and Blood Chemistry Parameters Differ in Free-Ranging Maned Wolves (Chrysocyon Brachyurus) Living in the Serra Da Canastra National Park Versus Adjacent Farmlands, Brazil

“…Exposure to organophosphate or carbamate insecticides significantly decreases cholinesterase activity (Furlanello et al, 2006). Stress also has been recognized to induce secretion of acetylcholinesterase, a type of cholinesterase that modulates hematopoiesis (Grisaru et al, 2001(Grisaru et al, , 2006 and neuronal functions (Small et al, 1996;Nizri et al, 2007), as well as promoting inflammation associated thrombopoiesis . Cholinesterase has also been suggested to play a role in tumorigenesis, especially in hemopoietic malignancies (Soreg et al, 1991).…”

Megakaryocyte development and platelet production

“…This unique peptide is derived from the cleavable C-terminus of the stress associated form of acetylcholinesterase (AChE), a molecule known to be involved in the regulation of megakaryocytopoiesis (Long et al, 1982;Lev-Lehman et al, 1997). This readthrough variant (AChE-R), is physiologically functional during stress thrombopoiesis and is currently in preclinical development as a new thrombopoietic factor (Grisaru et al, 2001;Deutsch et al, 2002;Pick et al, 2005).…”

Stress-induced alternative splicing of acetylcholinesterase results in enhanced fear memory and long-term potentiation

“…22 Therefore, we analysed whether elevated contextual fear observed under AChE-R overexpression could be mimicked by mARP, a synthetic peptide with the sequence of the mouse AChE-R C-terminus. FVB/N mice were first microinjected with rhodamine-labeled mARP to the lateral ventricle.…”

“…The purified product was characterized by MALDI-TOF mass spectrometry on a PerSeptive Biosystems Voyager Mass Spectrometer using acyano-4-hydoxycinnamic acid matrix: mass calculated 3543.8, mass found 3544.2. PBAN 22 was from Phoenix Pharmaceuticals (Belmont, CA, USA).…”