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Cellular and Molecular Mechanisms of Ischemic Acute Renal Failure and Repair
Published in Robin S. Goldstein, Mechanisms of Injury in Renal Disease and Toxicity, 2020
Joseph V. Bonventre, Ralph Witzgall
Renal brush border membranes are rich in proteases (Bond and Butler, 1987). The involvement of these proteases, which include meprin, endopeptidase 24.11, and exopeptidases, or the Ca2+-dependent neutral cysteine proteinases, calpains (Mellgren, 1987), in ischemic injury, is not well understood. Calpains have been implicated in a number of cellular functions, including membrane calcium channel regulation, protein kinase activity, receptor expression, and modification of cytoskeletal proteins (Belles, et al., 1988; Mellgren, 1987).
Mechanisms of Resistance to Antineoplastic Drugs
Published in Robert I. Glazer, Developments in Cancer Chemotherapy, 2019
Philip J. Vickers, Alan J. Townsend, Kenneth H. Cowan
In attempts to identify other proteins involved in the development of MDR, several workers have screened cells for the overexpression of proteins other than P-glycoprotein. Meyers and co-workers201,202 have reported the overexpression of a 22-kDa protein (termed V19 or sorcin) in MDR Chinese hamster and mouse cells selected for resistance to vincristine. A protein of similar size has been shown to be overexpressed in a number of other multidrug-resistant cell lines.203,204 This protein has been purified and sequenced and has been shown to have amino acid sequence homology with the calcium-binding light chain of calpain.205
Post-Exercise Recovery Period
Published in Atko Viru, Adaptation in Sports Training, 2017
Ca-activated proteinases — calpains — may have contributed to a post-exercise increase in protein turnover. After eight swims of 1 min with an additional load of 12% b.w. (rest intervals between repetitions 90 s) the activity of calpains remained at the control level during the first hours. The following increase in the calpains activity led to the highest level 24 h after the exercise. The high level was maintained for 60 h. A return to the control level was found only 96 h after the exercise.311
Rational repurposing, synthesis, in vitro and in silico studies of chromone-peptidyl hybrids as potential agents against Leishmania donovani
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2023
Ahmed H. E. Hassan, Waleed A. Bayoumi, Selwan M. El-Sayed, Trong-Nhat Phan, Yeon Ju Kim, Chae Hyeon Lee, Soo Bin Cho, Taegeun Oh, Gyeongpyo Ham, Kazem Mahmoud, Joo Hwan No, Yong Sup Lee
Calpains are a group of mammalian proteolytic proteins which are calcium-dependent cysteine proteases that are involved in several cellular functions. It was discovered that Leishmania has a calpain-like protein (CALP) whose inhibition was found to be connected to induction of Leishmania’s cell death25. Fortunately, MDL28170 (Figure 1) which was originally developed as an inhibitor of mammalian calpain cysteine proteases was found to show potential antileishmanial activity. MDL28170 showed a dose-dependent antiproliferative activity against L. amazonensis promastigotes26,27. Furthermore, another cysteine protease inhibitor derivative 2 (Figure 1) was discovered to possess potential antileishmanial activity28. Consequently, repurposing cysteine protease inhibitors, particularly, calpain inhibitors was suggested as an interesting rational to generate new antileishmanial lead compounds26,27,29,30.
m-Calpain is released from striatal synaptosomes
Published in International Journal of Neuroscience, 2023
Nina Pestereva, Irina Ivleva, Alexander Zubov, Maria Tikhomirova, Marina Karpenko
Calpains are a family of intracellular cysteine calcium-dependent proteases [1]. Sixteen representatives of this family are currently known: calpain1–calpain 15 (with different substrate and tissue specificity) and a highly specific endogenous inhibitor, calpastatin. Two of them are well studied: calpain 1 (or µ-calpain), which requires micromolar concentrations of Ca2+ for its activation, and calpain 2 (or m-calpain), which requires millimolar concentrations. Calpain substrates undergo limited proteolysis, resulting in the formation of stable protein fragments that lose properties of the intact molecule and acquire new, sometimes opposite, functions. Thus, calpains are involved in the regulation of many physiological functions. However, alterations in calcium homeostasis lead to pathologic activation of calpain in neurological, cardiovascular and metabolic diseases [1, 2].
Effects of 6-(Methylsulfinyl)hexyl Isothiocyanate Ingestion on Muscle Damage after Eccentric Exercise in Healthy Males: A Pilot Placebo-Controlled Double-Blind Crossover Study
Published in Journal of Dietary Supplements, 2022
Yoko Tanabe, Nobuhiko Akazawa, Mio Nishimaki, Kazuhiro Shimizu, Naoto Fujii, Hideyuki Takahashi
Many factors can contribute to the muscle damage-associated loss of muscle force, including abnormalities in excitation-contraction coupling (8), disruption in muscle fibers to force-generating structures such as actin and myosin (9), and altered central nervous system (10,11). In addition to these factors, recent animal studies suggest that a primarily calpain-associated proteolysis of key muscle contraction-associated proteins could, at least in part, lead to such a large and long-lasting, eccentric contraction-associated force deficit (12,13). A mechanical force, especially induced by eccentric contraction, leads to overstretching and disruption of sarcomeres. This response is followed by increased Ca2+ influx into the muscle cells due to mechanical disruption in the membrane (14) and opening stretch-activated Ca2+ channels (15). Ca2+ in the muscle cells then binds to the domain of calpain in a Ca2+-dependent manner, cleaving a variety of protein substrates including cytoskeletal and myofibrillar proteins such as α-actinin and titin, ultimately accelerating myofibrillar structure degradation (16,17). In addition, calpain activity inhibition promotes the restoration process of force production after eccentric contractions in mice (12) Therefore, if post-exercise calpain activity is suppressed, muscle damage and associated responses (e.g. elevated CK, U-titin, and T2) might be partially prevented.