A beta-lactone related to lactacystin induces neurite outgrowth in a neuroblastoma cell line and inhibits cell cycle progression in an osteosarcoma cell line.

Abstract

Lactacystin (structure 1 in Fig. 1) is a Streptomyces metabolite that inhibits cell proliferation and induces neurite outgrowth in the mouse neuroblastoma cell line Neuro 2A (1, 2). Cells induced to differentiate by treatment with lactacystin display a predominantly bipolar (two-neurite-bearing) morphology, particularly between 16 and 32 h after treatment, and become more multipolar (multiple-neurite-bearing) upon continued exposure, with increased branching of neurites. In contrast, serum deprivation or treatment of Neuro 2A cells with agents that increase intracellular cAMP levels tends to induce a predominantly multipolar type of neurite outgrowth (3, 4), whereas treatment with agents such as retinoic acid, natural gangliosides, and synthetic sialyl compounds tends to result in a predominantly unipolar (single-neurite-bearing) type of neurite outgrowth in the population of differentiated cells (3, 4).Mature neurons exhibit a variety ofphenotypes in terms of both morphology and physiology. In vertebrate development, neuroblasts from the neural tube and neural crest differentiate into specialized neurons with uni-, bi-or multipolar morphology depending on developmental history (5). The molecular mechanisms underlying these cell-fate determinations remain to be fully elucidated. Lactacystin may prove to be a useful reagent for studying the signal transduction pathways involved in neuronal differentiation and the induction of bipolar morphology. MATERIALS AND METHODSMaterials. Lactacystin used in the biological assays was provided by S. 'Omura of the Kitasato Institute. Lactacystin analogs were synthesized by methods reported elsewhere (6-9). The structure of clasto-lactacystin 3-lactone (structure 4 in Fig. 1 3358The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact.

The ubiquitin-proteasome pathway and synaptic plasticity

“…Later studies on LTF, however, showed that bath application of the active form of lactacystin, clasto-lactacystin b-lactone, to sensory-motor neuron synapses resulted in enhanced LTF and an increase in neurite outgrowth in isolated sensory neuron (Zhao et al 2003). The increase in neurite elongation is consistent with results obtained in PC12 and Neuro2A cells in which lactacystin induces neurite outgrowth (Fenteany et al 1994). Both sets of results can be reconciled if one postulates that proteasome has different roles in different cellular compartments (Hegde 2004).…”

In vivo degradation of N-myc in neuroblastoma cells is mediated by the 26S proteasome

“…Indeed, although some of the biochemical properties of the proteasome are well characterized (Orlowski, 1990;Orlowski et al, 1993), the physiologic functions of this proteinase complex have been di cult to study due to the lack of speci®c inhibitors. Recently, a novel streptomyces metabolite, lactacystin, discovered on the basis of its ability to induce neurite outgrowth in the murine neuroblastoma cell line Neuro-2A (Katagiri et al, 1995;Fenteany et al, 1994;Fenteany and Schreiber, 1996), has emerged as a highly speci®c, irreversible inhibitor of 26S proteasome chymotrypsin-like and trypsin-like activity, without a ecting lysosomal and nonlysosomal cysteine proteases, cathepsin or calpain (Fenteany et al, 1995). The inhibitory e ect of lactacystin on ubiquitin/ATP-dependent degradation of several proteins has been demonstrated both in mammalian cells (Blagosklonny et al, 1996;Bies and Wol , 1997;Oda et al, 1996;Mimnaugh et al, 1996;Lee and Goldberg, 1996; Je ers et al, 1997; Whitesell et al, 1997) and in yeast .…”

Lactacystin, Proteasome Function, and Cell Fate

“…1) was discovered on the basis of its ability to inhibit cell growth and to induce neurite outgrowth in a murine neuroblastoma cell line, Neuro-2a (3). The cytostatic effects of lactacystin are not unique to Neuro-2a cells (4), and lactacystin has been found to inhibit cell cycle progression in both the G 0 /G 1 and G 2 /M phases of the cell cycle (4,5). Lactacystin treatment of Neuro-2a cells results in a predominantly bipolar morphology with two long processes emanating from opposite sides of the cell body, maximal between 16 and 32 h after the start of treatment (4).…”