Ischemia-induced increase in long-term potentiation is warded off by specific calpain inhibitor PD150606

Farkas, Bence; Tantos, Ágnes; Schlett, Katalin; Világi, Ildikó; Friedrich, Péter

doi:10.1016/j.brainres.2004.07.059

Cited by 21 publications

(13 citation statements)

References 58 publications

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“…To further explore the usefulness of flow cytometric measurement of calpain activity, we used the assay to determine the inhibitory nature of 3‐(4‐iodophenyl)‐2‐mercapto‐(Z)‐2‐propenoic acid (PD 150606) in live cells (51–54). Calpain activity dependence on substrate concentration was measured at increasing concentrations of the inhibitor (Fig.…”

Section: Resultsmentioning

confidence: 99%

Flow cytometric measurement of calpain activity in living cells

Niapour

Berger

2007

Cytometry Pt A

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Background: Calpains are intracellular, calcium‐sensitive, neutral cysteine proteases that play crucial roles in many physiological and pathological processes. Calpain regulation is complex and activity is poorly correlated with calpain protein levels. Therefore a full understanding of calpain function requires robust methods for measuring activity. Methods: We describe and characterize a flow cytometric method for measuring calpain activity in live cells. This method uses the BOC‐LM‐CMAC reagent that readily diffuses into cells where it reacts with free thiols to enhance retention. Results: We show that the reagent is cleaved specifically by calpains and follows saturation kinetics. We use the assay to measure calpain activation following PDGF stimulation of rat fibroblasts. We also show that the calpain inhibitor PD150606 inhibits calpain with a Ki of 12.5 μM and show that Mek inhibitors PD89059 and U0126 also suppress calpain activity. We also show that the assay can measure calpain activity in subpopulations of cells present in unfractionated cord blood or in HL60 human myelomonocytic leukemia cells. Conclusion: Taken together, these experiments demonstrate that this assay is a reliable and useful method for measuring calpain activity in multiple cell types. © 2007 International Society for Analytical Cytology

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Section: Resultsmentioning

confidence: 99%

Flow cytometric measurement of calpain activity in living cells

Niapour

Berger

2007

Cytometry Pt A

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“…These findings suggest that calpastatin overexpression in this transgenic line does not produce notable changes in baseline learning and memory functions, despite evidence implicating calpains in hippocampal long-term potentiation (LTP). Application of calpain inhibitors has been shown to reduce or block hippocampal LTP (del Cerro et al, 1990, Denny et al, 1990, Suzuki et al, 1992, Farkas et al, 2004), although some inhibitors tested were not selective. Conversely, rats with a genetic deficiency in calpastatin exhibited enhanced LTP (Muller et al, 1995).…”

Section: Discussionmentioning

confidence: 99%

Calpastatin overexpression limits calpain-mediated proteolysis and behavioral deficits following traumatic brain injury

Schoch

Evans

Brelsfoard

et al. 2012

Experimental Neurology

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Traumatic brain injury (TBI) results in abrupt, initial cell damage leading to delayed neuronal death. The calcium-activated proteases, calpains, are known to contribute to this secondary neurodegenerative cascade. Although the specific inhibitor of calpains, calpastatin, is present within neurons, normal levels of calpastatin are unable to fully prevent the damaging proteolytic activity of calpains after injury. In this study, increased calpastatin expression was achieved using transgenic mice that overexpress the human calpastatin (hCAST) construct under control of a calcium-calmodulin dependent kinase II α promoter. Naïve hCAST transgenic mice exhibited enhanced neuronal calpastatin expression and significantly reduced protease activity. Acute calpain-mediated spectrin proteolysis in the cortex and hippocampus induced by controlled cortical impact brain injury was significantly attenuated in calpastatin overexpressing mice. Aspects of posttraumatic motor and cognitive behavioral deficits were also lessened in hCAST transgenic mice compared to their wildtype littermates. However, volumetric analyses of neocortical contusion revealed no histological neuroprotection at either acute or long-term time points. Partial hippocampal neuroprotection observed at a moderate injury severity was lost after severe TBI. This study underscores the effectiveness of calpastatin overexpression in reducing calpain-mediated proteolysis and behavioral impairment after TBI, supporting the therapeutic potential for calpain inhibition. In addition, the reduction in spectrin proteolysis without accompanied neocortical neuroprotection suggests the involvement of other factors that are critical for neuronal survival after contusion brain injury.

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“…In the early phase of global hypoperfusion damage, glutamate-evoked NMDA receptor activation contributes to the increase in the cytosolic Ca 2+ concentration (Dirnagl et al, 2003;Zhang and Lipton, 1999). The CA1 region of the hippocampus is particularly vulnerable to the permanent hypoxic conditions induced by 2VO (de la Torre et al, 1997;Farkas et al, 2004;Pappas et al, 1996). The present study has revealed that the acute brain hypoperfusion induced by 2VO also results in an immediate dysfunction of the CA1 region: the amplitude of the CA3 stimulation-evoked population spikes in the CA1 region decreases.…”

Section: Discussionmentioning

confidence: 99%