Calpeptin provides functional neuroprotection to rat retinal ganglion cells following Ca2+ influx

Das, Arabinda; Garner, Dena P.; Re, Angelo M. Del; Woodward, John J.; Kumar, D.M.; Agarwal, Neeraj; Banik, Naren L.; Ray, Swapan K.

doi:10.1016/j.brainres.2006.02.051

Cited by 72 publications

(55 citation statements)

References 66 publications

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“…We have recently observed that these effects could be abolished by chelation of extracellular Ca 2ϩ (using EDTA⅐Na) or by use of an inhibitor of the Na ϩ /Ca 2ϩ exchanger (Inokuchi et al, 2009). Furthermore, exposing RGC-5 cells in culture to ionomycin (a calcium ionophore) or interferon-␥ increases intracellular Ca 2ϩ influx, and calpeptin (a calpain-specific inhibitor) attenuates both proteolytic activities and apoptosis (Das et al, 2006). These findings support the idea that calpain activation may be involved in the RGC cell death seen under hypoxic conditions.…”

Section: Discussionsupporting

confidence: 61%

A Novel Calpain Inhibitor, ((1S)-1-((((1S)-1-Benzyl-3-cyclopropylamino-2,3-di-oxopropyl)amino)carbonyl)-3-methylbutyl)carbamic Acid 5-Methoxy-3-oxapentyl Ester (SNJ-1945), Reduces Murine Retinal Cell Death In Vitro and In Vivo

Shimazawa¹,

Suemori²,

Inokuchi³

et al. 2009

J Pharmacol Exp Ther

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We examined whether ((1S)-1-((((1S)-1-benzyl-3-cyclopropylamino-2,3-di-oxopropyl)amino)carbonyl)-3-methylbutyl)carbamic acid 5-methoxy-3-oxapentyl ester (SNJ-1945), a new orally available calpain inhibitor, might reduce retinal cell death in vivo and/or in vitro. Retinal cell damage was induced in vivo in mice by intravitreal injection of N-methyl-D-aspartate (NMDA), and SNJ-1945 was intraperitoneally or orally administered twice. NMDA-induced calpain activity (measured as the cleaved products of ␣-spectrin) and its substrate, p35 (a neuron-specific activator for cyclin-dependent kinase 5), in the retina were examined by immunoblotting. In RGC-5 (a rat retinal ganglion cell line) cell culture, cell damage was induced by a 4-h oxygenglucose deprivation (OGD) treatment followed by an 18-h reoxygenation period. In mouse retinas, SNJ-1945 (30 or 100 mg/kg i.p., 100 or 200 mg/kg p.o.) significantly inhibited the cell loss in the ganglion cell layer (GCL) and the thinning of the inner plexiform layer induced by NMDA. Furthermore, the number of positive cells for terminal deoxynucleotidyl transferase dUTP nick-end labeling was significantly reduced in the GCL and the inner nuclear layer of retinas treated with SNJ-1945 compared with vehicle-treated retinas 24 h after NMDA injection. Levels of cleaved ␣-spectrin products increased and p35 decreased 6 h after NMDA injection or later, and their effects were attenuated by SNJ-1945. In vitro, SNJ-1945 (10 and 100 M) inhibited the OGD stress-induced reduction in cell viability. In conclusion, SNJ-1945 may afford valuable neuroprotection against retinal diseases, because it was effective against retinal damage both in vitro and in vivo. Our results also indicate that calpain activation and subsequent p35 degradation may be involved in the mechanisms underlying retinal cell death.Retinal ganglion cell (RGC) death is a common feature of many ophthalmic disorders, including glaucoma, optic neuropathies, and various retinovascular diseases (diabetic retinopathy and retinal vein occlusions). Retinal ganglion cells are extremely sensitive to the effects of both glutamate and its analog N-methyl-D-aspartate (NMDA), both of which produce a dosedependent cell loss in vivo and in vitro. In addition, glutamate toxicity has been implicated in the pathophysiology of glaucoma (Dreyer, 1998). Activation of Ca 2ϩ -permeable NMDA receptors and the subsequent neuronal Ca 2ϩ overloading have been shown to mediate glutamate-induced neuron death (Choi, 1994). Induction of the Ca 2ϩ -activated neutral cysteine protease -calpain by micromolar concentrations of Ca 2ϩ occurs early in excitotoxic neuron death (Siman et al., 1989;Faddis et al., 1997). Similar to the caspases, -calpain cleaves a variety of cytoskeletal proteins, enzymes, and transcription factors and could also interfere with the proteolytic activity of the caspases (Croall and DeMartino, 1991).

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Section: Discussionsupporting

confidence: 61%

A Novel Calpain Inhibitor, ((1S)-1-((((1S)-1-Benzyl-3-cyclopropylamino-2,3-di-oxopropyl)amino)carbonyl)-3-methylbutyl)carbamic Acid 5-Methoxy-3-oxapentyl Ester (SNJ-1945), Reduces Murine Retinal Cell Death In Vitro and In Vivo

Shimazawa¹,

Suemori²,

Inokuchi³

et al. 2009

J Pharmacol Exp Ther

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“…The proteolysis of calpastatin suggests a cross-talk between the caspase and calpain systems in course of apoptosis in T98G and U87MG cells. The degradation of 270 kD α-spectrin to 145 kD spectrin breakdown product (SBDP) and 120 kD SBDP has been attributed to increased activities of calpain and caspase-3, respectively (Das et al, 2005(Das et al, ,2006(Das et al, ,2007(Das et al, , 2008. So, we examined increases in calpain and caspase-3 activities in the formation of 145 kD SBDP and 120 kD SBDP, respectively, on the Western blots (Fig.…”

Section: -Hpr Increased Intracellular Free [Ca 2+ ] Activated Calpamentioning

confidence: 99%

N-(4-Hydroxyphenyl) retinamide induced both differentiation and apoptosis in human glioblastoma T98G and U87MG cells

2008

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N-(4-Hydroxyphenyl) retinamide (4-HPR) is a synthetic retinoid that has shown biological activity against several malignant tumors and minimal side effects in humans. To explore the mechanisms underlying the chemotherapeutic effects of 4-HPR in glioblastoma, we used two human glioblastoma T98G and U87MG cell lines. In situ methylene blue staining showed the morphological features of astrocytic differentiation in glioblastoma cells following exposure to 1 µM and 2 µM 4-HPR for a short duration (24 h). Astrocytic differentiation was associated with an increase in expression of glial fibrillary acidic protein (GFAP) and down regulation of telomerase. Wright staining and ApopTag assay indicated appearance of apoptotic features in glioblastoma cells following exposure to 1 µM and 2 µM 4-HPR for a long duration (72 h). We found that 4-HPR caused apoptosis with activation of caspase-8 and cleavage of Bid to truncated Bid (tBid). Besides, apoptosis was associated with alterations in expression of pro-apoptotic Bax and anti-apoptotic Bcl-2 proteins resulting in an increase in Bax:Bcl-2 ratio, mitochondrial release of cytochrome c and Smac, down regulation of selective baculoviral inhibitor-of-apoptosis repeat containing (BIRC) molecules, an increase in intracellular free [Ca 2+ ], and activation of calpain and caspase-3. Taken together, these results strongly suggested that 4-HPR could be used at low doses for induction of both differentiation and apoptosis in human glioblastoma cells.

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“…Active caspase-8 processes Bid to truncated Bid (tBid), the C-terminal part of Bid, which is then translocated to mitochondrial membrane to trigger cytochrome c release and activation of caspase-9 [12][13][14]. On the other hand, drug-induced stress initiates the intrinsic pathway of apoptosis to activate apical caspase-9 directly.…”

Section: Introductionmentioning

confidence: 99%

Molecular Mechanisms of the Combination of Retinoid and Interferon-gamma for Inducing Differentiation and Increasing Apoptosis in Human Glioblastoma T98G and U87MG Cells

2008

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Glioblastoma is the deadliest brain tumor that remains incurable. We examined efficacy of combination of retinoid and interferon-gamma (IFN-gamma) in human glioblastoma T98G and U87MG cells. We conjectured that retinoid could induce differentiation with down regulation of telomerase activity to increase sensitivity to IFN-gamma for apoptosis in glioblastoma cells. Indeed, treatment of cells with 1 muM all-trans retinoic acid (ATRA) or 1 muM 13-cis retinoic acid (13-CRA) for 7 days induced astrocytic differentiation with upregulation of glial fibrillary acidic protein (GFAP) and down regulation of telomerase activity. Wright staining and ApopTag assay showed, respectively, morphological and biochemical features of apoptosis in glioblastoma cells following exposure to 200 units/ml IFN-gamma for 48 h. Induction of differentiation was associated with decreases in levels of nuclear factor kappa B (NFkappaB), inducible nitric oxide synthase (iNOS), and production of nitric oxide (NO) so as to increase sensitivity to IFN-gamma for apoptosis. Notably, IFN-gamma induced signal transducer and activator of transcription-1 (STAT-1) to bind to gamma-activated sequence (GAS) of the target gene. Also, IFN-gamma activated caspase-8 and cleaved Bid to truncated Bid (tBid) for translocation to mitochondria. Fura-2 assay showed increases in intracellular free [Ca2+] and activation of calpain in apoptotic cells. Besides, increases in Bax:Bcl-2 ratio and mitochondrial release of cytochrome c and Smac into the cytosol activated caspase-9 and caspase-3 for apoptosis. Taken together, our results showed that retinoid induced astrocytic differentiation with down regulation of telomerase activity and enhanced sensitivity to IFN-gamma for increasing apoptosis in human glioblastoma cells.

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Calpeptin provides functional neuroprotection to rat retinal ganglion cells following Ca2+ influx

Cited by 72 publications

References 66 publications

A Novel Calpain Inhibitor, ((1S)-1-((((1S)-1-Benzyl-3-cyclopropylamino-2,3-di-oxopropyl)amino)carbonyl)-3-methylbutyl)carbamic Acid 5-Methoxy-3-oxapentyl Ester (SNJ-1945), Reduces Murine Retinal Cell Death In Vitro and In Vivo

A Novel Calpain Inhibitor, ((1S)-1-((((1S)-1-Benzyl-3-cyclopropylamino-2,3-di-oxopropyl)amino)carbonyl)-3-methylbutyl)carbamic Acid 5-Methoxy-3-oxapentyl Ester (SNJ-1945), Reduces Murine Retinal Cell Death In Vitro and In Vivo

N-(4-Hydroxyphenyl) retinamide induced both differentiation and apoptosis in human glioblastoma T98G and U87MG cells

Molecular Mechanisms of the Combination of Retinoid and Interferon-gamma for Inducing Differentiation and Increasing Apoptosis in Human Glioblastoma T98G and U87MG Cells

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