9a, 9f)

9a, 9f). in RR-EAE mice was tested. Incubating MBP-specific T cells with the calpain inhibitor SJA6017 before AT markedly suppressed the ability of these T cells to induce clinical symptoms of RR-EAE. These reductions correlated with decreases in demyelination, inflammation, axonal damage, and loss of oligodendrocytes and neurons. Also, calpain:calpastatin ratio, production of tBid, and Bax:Bcl-2 ratio, and activities of calpain and caspases, and internucleosomal DNA fragmentation were attenuated. Thus, these data suggest calpain as a encouraging target for treating EAE and MS. 2002). MS is usually thought to develop as a result of an infiltration of myelin-reactive T cells and other immune cells into the CNS, resulting in inflammation, myelin degradation, axonal damage, and loss of neurons and oligodendrocytes (Peterson 2001; Keegan and Noseworthy 2002). Whether or not immune components of MS pathology occur before Pixantrone or in conjunction with neurodegenerative components is still under argument, and studies have exhibited that axonal damage occurs early in disease progression and correlates with disease severity (Trapp 1999). Since the total etiology is not clearly comprehended, long-term effective therapies for MS have not yet been developed; however, only treatments are anti-inflammatory drugs that provide temporary relief by reducing the inflammatory responses. Nevertheless, the degradation of myelin proteins in the CNS of MS patients has previously implicated the involvement of various proteases in the pathogenesis of this disease (Einstein 1972; Cuzner 1975; Banik 1979) and thus proteases are therapeutic targets utilizing protease inhibitors as intervening agents (Govindarajan 1974; Marks 1974). The calcium (Ca2+)-dependent protease calpain was postulated to be involved in MS more than two decades ago (Banik 1985; de Rosbo and Bernard 1989). Calpain exists as ubiquitous and tissue-specific isoforms that are dependent on Ca2+ for activation and the ubiquitous isoforms of calpain, calpain and mcalpain, are activated by M and mM Ca2+ concentrations, respectively (Hassen 2006). Over the years, support for the involvement of ubiquitous isoforms of KLK7 antibody calpain in demyelinating diseases has accumulated (Shields 1999; Schaecher 2001a). Calpain expression and activity are increased in spinal cord and optic nerve of animals with experimental autoimmune encephalomyelitis (EAE), an animal model of MS (Shields 1998a; Shields 1998b), as well as in postmortem tissues from the patients with MS (Shields and Banik 1999; Diaz-Sanchez 2006). Increased calpain activity correlated with disease onset, T cell and macrophage migration into the CNS, axonal damage, and neuronal loss in an acute EAE rat model (Schaecher 2002; Guyton et al. 2005). Calpain is also involved in the activation of T cells (Deshpande 1995b; Schaecher 2001b) and when released from activated T cells, it degrades myelin basic protein (MBP) and other myelin components (Deshpande 1995a) strongly suggesting a role for calpain in perpetuating immune-mediated demyelination by calpain-cleaved antigenic peptides. Nuclear factor kappa-B (NF-B) is a nuclear transcription factor that plays a key role in increasing the expression of many pro-inflammatory mediators, including inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) (Surh 2001). Calpain causes indirectly the activation and nuclear translocation of NF-B via degradation of the inhibitor of B-alpha (IB) (Schaecher 2004). Calpain has also been linked to neurodegenerative events such axonal damage and loss of neurons and oligodendrocytes (Guyton 2005; Cerghet 2006), at least partially through modulation of proteins involved in classical receptor and mitochondrial apoptotic pathways (Das 2008). Targeting multiple pathogenic events of a disease has been postulated to offer better therapy in heterogeneous diseases such as MS. Since calpain has been implicated in both Pixantrone immune and neurodegenerative arms of MS and EAE, blocking this protease may inhibit multiple pathways linked to disability. Although calpain is regulated by its endogenous inhibitor calpastatin, in reality calpastatin is too large to Pixantrone be used as a therapeutic agent (Higuchi 2005). Therefore, synthetic cell-permeable calpain inhibitors have been developed for using in the treatment of neurodegenerative diseases including animal models of Parkinsons disease (PD), Alzheimers disease (AD), spinal cord injury (SCI), and traumatic brain injury (TBI) (Ray and Banik 2003). Calpain inhibitors have also proven effective in reducing clinical symptoms of EAE in.