Beneficial effect of new thiol protease inhibitors, epoxide derivatives, on dystrophic mice

Komatsu, Keiji; Inazuki, Kohko; Hosoya, Jun; Satoh, Susumu

doi:10.1016/0014-4886(86)90022-1

Cited by 32 publications

(21 citation statements)

References 14 publications

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“…E-64d was also found to significantly alleviate clinical arthritis in murine monoclonal antibodyinduced arthritis [200]. In addition, E-64 and E-64d reduce muscle degeneration in dystrophic mice and hamster models [193,201], while E-64, E-64c and E-64d reduce nuclear opacity and proteolysis of crystallins in calcium ionophoreinduced cataract lenses [195]. The benzyloxycarbonyl substituted derivative Ep-460 (Fig.…”

Section: Epoxysuccinate Derivativesmentioning

confidence: 90%

Calpains: Attractive Targets for the Development of Synthetic Inhibitors

Pietsch

Chua²,

Abell

2010

CTMC

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The physiological roles of calpains are discussed, as are the associated pathological disorders that result from their over-activation. We also present practical information for establishing functional inhibition assays and an overview of X-ray crystal structures of calpain-inhibitor complexes to aid inhibitor design. These structures reveal the expected extended beta-strand conformation for the inhibitor backbone, a geometry that has been engineered into inhibitors with the introduction of either an N-terminal heterocycle or a macrocycle that links the P(1) and P(3) residues. The structure and function of all the main classes of inhibitors are reviewed, with most examples being classified according to the nature of the C-terminal reactive warhead group that reacts with the active site cysteine of calpains. These inhibitor classes include epoxysuccinate derivatives, aldehydes, aldehyde prodrugs (hemiacetals) and alpha-keto carbonyl compounds. Inhibitors derived from the endogenous inhibitor calpastatin and examples lacking a warhead, are now known and these are also discussed.

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Section: Epoxysuccinate Derivativesmentioning

confidence: 90%

Calpains: Attractive Targets for the Development of Synthetic Inhibitors

Pietsch

Chua²,

Abell

2010

CTMC

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“…Normoxic tubules demonstrated significant membrane injury with E-64-d, suggesting that E-64-d has nonspecific effects or that complete inhibition of calpain activity in normoxic tubules is damaging. The possibility that 100% inhibition of calpain may be damaging to normoxic tubules is suggested by the regulatory role of calpain in cytoskeletal or cell membrane modeling during normal cell development (33). In spite of this deleterious effect in normoxic tubules, E-64-d elicited cytoprotection against both 15 and 25 min of hypoxia.…”

Section: Discussionmentioning

confidence: 99%

The role of cysteine proteases in hypoxia-induced rat renal proximal tubular injury.

Edelstein

Wieder

Yaqoob

et al. 1995

Proc. Natl. Acad. Sci. U.S.A.

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The role of the lysosomal proteases cathepsins B and L and the calcium-dependent cytosolic protease calpain in hypoxia-induced renal proximal tubular injury was investigated. As compared to normoxic tubules, cathepsin B and L activity, evaluated by the specific fluorescent substrate benzyloxycarbonyl-L-phenylalanyl-L-arginine-7-amido-4-methylcoumarin, was not increased in hypoxic tubules or the medium used for incubation of hypoxic tubules in spite of high lactate dehydrogenase (LDH) release into the medium during hypoxia. These data in rat proximal tubules suggest that cathepsins are not released from lysosomes and do not gain access to the medium during hypoxia. An assay for calpain activity in isolated proximal tubules using the fluorescent substrate N-succinyl-Leu-Tyr-7-amido-4-methylcoumarin was developed. The calcium ionophore ionomycin induced a dose-dependent increase in calpain activity. This increase in calpain activity occurred prior to cell membrane damage as assessed by LDH release. Tubular calpain activity increased signifi'cantly by 7.5 min of hypoxia, before there was significant LDH release, and further increased during 20 min of hypoxia. The cysteine protease inhibitor N-benzyloxycarbonyl-Val-Phe methyl ester (CBZ) markedly decreased LDH release after 20 min of hypoxia and completely prevented the increase in calpain activity during hypoxia. The increase in calpain activity during hypoxia and the inhibitor studies with CBZ therefore supported a role for calpain as a mediator of hypoxia-induced proximal tubular injury.The mechanisms responsible for hypoxia-induced tubular epithelial cell injury and death are controversial (1). Intracellular calcium has been suggested to be important in mediation of this hypoxic injury in renal proximal tubules (2). Our laboratory recently reported that cytosolic free Ca2+ [(Ca2+)i] is significantly increased by 2 min of hypoxia in proximal tubules, and that (Ca2+)i levels at 10 min of hypoxia correlated with subsequent damage at 20 min (3). Thus, prompt increases in (Ca2+), may play an initiating role in hypoxic injury. This conclusion was supported by the protection afforded by prevention of the increase in (Ca2+), (3,4). The mechanisms whereby increases in (Ca2+), lead to cell membrane injury, however, remain to be defined. An increase in (Ca2+)i may activate calcium-dependent enzymes, which could provide a mechanism for cell injury. The increase in (Ca2+)i during hypoxia may activate phospholipase A2 and thus be partly responsible for phospholipid degradation in membranes observed during hypoxia (5). Another potential mechanism for calcium-dependent cell injury is activation of the calciumdependent cytosolic protease calpain. In certain circumstances, proteases have been shown to play a role in cellular injury. For example, studies with cultured fibroblasts and the specific lysosomotropic detergent C12-imidazole demonstrated that cell killing can be caused by activation and/or release into the cytoplasm of cysteine proteases (6). Studies of cysteine p...

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“…The peptidyl epoxides are highly selective for cysteine proteases but do not show any greater inhibitory activity against calpains relative to other cysteine proteases [208]. Administration of E64D in vivo has been reported to reduce muscle degeneration and muscular dystrophy in dystrophic mice and hamster models [209,210]. E64D also provides significant neuroprotection following spinal cord injury in rats [168].…”

Section: Peptidyl Epoxidesmentioning

confidence: 96%

Calpain Inhibition: A Therapeutic Strategy Targeting Multiple Disease States

Carragher¹

2006

CPD

150

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The calpains represent a well-conserved family of calcium-dependent cysteine proteases. They consist of several ubiquitous and tissue specific isoforms and exhibit broad substrate specificity influencing many aspects of cell physiology including migration, proliferation and apoptosis. Calpain activity in vivo is tightly regulated by its natural endogenous inhibitor calpastatin. Calpastatin specifically inhibits calpain and not other cysteine proteases by interaction with several sites on the calpain molecule. Inappropriate regulation of the calpain-calpastatin proteolytic system is associated with several important human pathological disorders including muscular dystrophy, cancer, Alzheimer's disease, neurological injury, ischaemia/reperfusion injury, atherosclerosis, diabetes and cataract formation. Recent advances in elucidating the tertiary structures of calpain 2 and its regulatory domain calpain 4, together with identification of new modes of regulating calpain activity provide new opportunities for the design of novel calpain inhibitors. Several classes of inhibitors, including peptidyl epoxide, aldehyde, and ketoamide inhibitors, targeting the active site have proven effective against the calpains and are in the process of evaluation in animal models of human disease. However, a major limitation to the clinical use of such inhibitors is their lack of specificity among cysteine proteases and other proteolytic enzymes. The development of a new class of calpain inhibitors that interact with domains outside of the catalytic site of calpain may provide greater specificity and therapeutic potential.

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Beneficial effect of new thiol protease inhibitors, epoxide derivatives, on dystrophic mice

Cited by 32 publications

References 14 publications

Calpains: Attractive Targets for the Development of Synthetic Inhibitors

Calpains: Attractive Targets for the Development of Synthetic Inhibitors

The role of cysteine proteases in hypoxia-induced rat renal proximal tubular injury.

Calpain Inhibition: A Therapeutic Strategy Targeting Multiple Disease States

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