• Animal cells and systems
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• 제5권4호
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• pp.267-274
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• 2001

Calpains are a family of cysteine proteases existing primarily in two forms designated by the $Ca^{2+}$ concentration needed for activation in vitro, $\mu$-calpain (calpain-I) and m-calpain (calpain-II). The physiologica1 roles of calpains remain unclear. Many groups have proposed a role for calpains In apoptosis, but their patterns of activation are not well characterized. Calpains have been implicated in neutrophil apoptosis, glucocorticoid-induced thymocyte apoptosis, as well as many other apoptotic pathways. Calpain activation in apoptosis is usually linked upstream or downstream to caspase activation, or in a parallel pathway alongside caspase activation. Calpains have been suggested to be involved in DNA fragmentation (via endonuclease activation), but also as effector proteases that cleave cellular proteins involved in DNA repair, membrane associated proteins and other homeostatic regulatory proteins. Recently, our laboratory demonstrated $\mu$-calpain activation in NAD(P)H: quinone oxidoreducatse 1 (NQO1)-expressing cells after exposure to $\beta$-lapachone, a novel quinone and potential chemo- and radio-therapeutic agent. Increased cytosolic $Ca^{2+}$ in NQO1-expressing cells after $\beta$-lapachone exposures were shown to lead to $\mu$-calpain activation. In turn, $\mu$-calpain activation was important for substrate proteolysis and DNA fragmentation associated with apoptosis. Upon activation, $\mu$-calpain translocated to the nucleus where it could proteolytically cleave PARP and p53. We provided evidence that $\beta$-lapachone-induced, $\mu$-calpain stimulated, apoptosis did not involve any of the known caspases; known apoptotic caspases were not activated after $\beta$-lapachone treatment of NQO1-expressing cells, nor did caspase inhibitors have any effect on $\beta$-1apachone-induced cell death. Elucidation of processes by which $\beta$-1apachone-stimulated $\mu$-calpain activation and calpains ability to activate endonucleases and induce apoptosis independent of caspase activity will be needed to further develop/modulate $\beta$-lapachone for treatment of human cancers that over-express NQO1.

• Bulletin of the Korean Chemical Society
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• 제32권9호
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• pp.3459-3464
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• 2011

In order to extend the scaffold of non-peptidic calpain inhibitor, we have designed and synthesized 14 chalcone derivatives categorized into two groups based on their structures. Compounds 7 ($IC_{50}=16.67{\pm}0.42{\mu}M$) and 8 ($IC_{50}=16.92{\pm}0.14{\mu}M$) in group A were most selective ${\mu}$-calpain inhibitor over cathepsins B and L. On the other hand, compound 14 possessing furan ring exhibited inhibitory activities for ${\mu}$-calpain ($IC_{50}=15.39{\pm}1.34{\mu}M$) as well as cathepsin B ($IC_{50}=20.59{\pm}1.35{\mu}M$). The results discovered implicated that chalcone analogues possessing proper size and functional groups can be a potential lead core for selective non-peptidic ${\mu}$-calpain inhibitor. Furthermore, dual inhibitors for ${\mu}$-calpain and cathepsin B can also be developed from chalcones by elaborate structure manipulation.

• Animal cells and systems
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• 제16권6호
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• pp.431-437
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• 2012

Calpains are a class of proteins that belong to the calcium-dependent, non-lysosomal cysteine proteases. There are three major types of calpains expressed in the skeletal muscle, namely, ${\mu}$-calpain, m-calpain, and calpain 3, which show proteolytic activities. Skeletal muscle fibers possess all three calpains, and they are $Ca^{2+}$-dependent proteases. The functional role of calpains was found to be associated with apoptosis and myogenesis. However, calpain 3 is likely to be involved in sarcomeric remodeling. A defect in the expression of calpain 3 leads to limb-girdle muscular dystrophy type 2A. Calpain 3 is found in skeletal muscle fibers at the N2A line of the large elastic protein, titin. A substantial proportion of calpain 3 is activated 24 h following a single bout of eccentric exercise. In vitro studies indicated that calpain 3 can be activated 2-4 fold higher than normal resting cytoplasmic [$Ca^{2+}$]. Characterization of the calpain system in the developing muscle is essential to explain which calpain isoforms are present and whether both ${\mu}$-calpain and m-calpain exist in differentiating myoblasts. Information from such studies is needed to clarify the role of the calpain system in skeletal muscle growth. It has been demonstrated that the activation of ubiquitous calpains and calpain 3 in skeletal muscle is very well regulated in the presence of huge and rapid changes in intracellular [$Ca^{2+}$].

• Asian-Australasian Journal of Animal Sciences
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• 제15권12호
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• pp.1747-1753
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• 2002

The objectives of this study were to examine the effect of early short-term temperature conditioning on metabolic rate and calpain/calpastatin system and to compare variations in metabolic rate and calpain/calpastatin system between Hanwoo and Holstein beef. Longissimus thoracis et lumborum of the right carcass from 3 Hanwoo and 3 Holstein bulls were removed within 30 min of exsanguinations, cut into three pieces, and then temperature conditioned until 3 h postmortem (PM) at 2, 16, and $30^{\circ}C$, respectively. Rigor values (R-values; $R_248$, $R_250$, and $R_258$), pH, muscle temperature, glycogen content, $\mu$- and m-calpain activities, and calpastatin acitivity were measured at 1, 3, 9, and 24 h PM, respectively. Hanwoo beef had higher muscle temperature, faster metabolic rate at early PM stage in R-values, and lower $\mu$-calpain activity than Holstein beef (p<0.05). The $30^{\circ}C$ treatment maintained muscle temperature of $30^{\circ}C$ until 3 h PM and resulted in faster pH decline at 3 and 9 h PM (p<0.05) than other treatments. The $16^{\circ}C$ had higher (p<0.05) muscle temperature at 3 h PM than the $2^{\circ}C$, but no difference in all other traits was observed between the $2^{\circ}C$ and the $16^{\circ}C$. Early shortterm temperature treatment used in this study was not sufficient to effectively activate calpain/calpastatin system. Correlations among all traits except m-calpain and muscle temperature were generally high (r>0.60; p<0.001). Among R-values, $R_258$ had higher correlations with other metabolic traits than those of $R_248$ and $R_250$. These data suggest that early PM metabolic rate, $\mu$-calpain activity, and calpastatin activity may be closely related to each other. Variations in metabolic rate and $\mu$-calpain activity at early PM stage between Hanwoo and Holstein beef may imply variations in meat quality between both breeds.

• Journal of Microbiology and Biotechnology
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• 제8권2호
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• pp.188-190
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• 1998

Penicillide, having a 5H, 7H-dibenzo［b,g］［1,5］ dioxocin-5-one skeleton, was isolated from the culture broth of Penicillium sp. F60760 as a nonpeptide inhibitor of calpain, a calcium-activated papain-like protease. The $IC_50$ value for the effect of penicillide against m-calpaln was $7.1{\mu}M$. However, penicillide did not inhibit papain at a concentration of $200{\mu}M$. These results suggest that penicillide is a new class of nonpeptide calpain inhibitor having an eight membered lactone ring.

• Natural Product Sciences
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• 제18권2호
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• pp.102-105
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• 2012

Marine organism extracts were prepared from 26 species of Korean indigenous marine organisms, including 25 species belonging in class Anthozoa of phylum Cnidaria and a species belonging to subphylum Urochordata of phylum Chordata, and screened their inhibitory effects against ${\mu}$-calpain. As a result, the thirteen extracts were found to be active in the criteria of $IC_{50}$ < 100 ${\mu}g/ml$. Among them, the MeOH extracts of Plexauroides praelonga and Alveopora japonica showed remarkable ${\mu}$-calpain inhibitory activity with $IC_{50}$ values of $4.62{\pm}0.22$ and $4.82{\pm}0.07{\mu}g/ml$, respectively. In addition, chemical investigation of A. japonica led to the isolation of an active compound, hexadecyl tetradecanoate, as a selective cathepsin B inhibitor ($IC_{50}=9.05{\pm}2.45{\mu}M$). This compound was isolated as constituent of A. japonica for the first time in the present study.

• Bulletin of the Korean Chemical Society
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• 제27권7호
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• pp.1001-1004
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• 2006

The m-calpain activity hydrolyzing a fluorogenic substrate of N-Succinyl-Leu-Leu-Val-Tyr-7-amino-4-methylcourmarin (LLVY-AMC) was significantly stimulated by more than two-fold in the presence of 5$\mu$M $\alpha$synuclein at $15{^{\circ}C}$. The stimulation was also confirmed with azocasein. The stimulation of the peptide hydrolyzing activity required structural intactness of $\alpha$-synuclein since the C-terminally or N-terminally modified proteins such as $\beta$-synuclein, $\alpha$-syn1-97, and $\alpha$-syn61-140 did not increase the proteolytic activity. Instead, however, the N-terminally truncated $\alpha$-syn61-140 was shown to drastically suppress the calpain activity. Since the N-terminal truncation was known to be the primary cleaving event of calpain-mediated proteolysis of $\alpha$-synuclein and the $\alpha$-syn61-140 has been demonstrated to be resistant against the calpain digestion, it has been proposed that the intracellular calpain activity could be regulated in a reciprocal manner by $\alpha$-synuclein and its proteolyzed C-terminal fragment. Based on the results, a possible physiological function of $\alpha$-synuclein has been suggested as a calpain regulator which contains both stimulatory and inhibitory activities.

• Parasites, Hosts and Diseases
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• 제49권2호
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• pp.177-180
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• 2011

Entamoeba histolytica is an enteric tissue-invading protozoan parasite that can cause amebic colitis and liver abscess in humans. E. histolytica has the capability to kill colon epithelial cells in vitro; however, information regarding the role of calpain in colon cell death induced by ameba is limited. In this study, we investigated whether calpains are involved in the E. histolytica-induced cell death of HT-29 colonic epithelial cells. When HT-29 cells were co-incubated with E. histolytica, the propidium iodide stained dead cells markedly increased compared to that in HT-29 cells incubated with medium alone. This pro-death effect induced by ameba was effectively blocked by pretreatment of HT-29 cells with the calpain inhibitor, calpeptin. Moreover, knockdown of m- and ${\mu}$-calpain by siRNA significantly reduced E. histolytica-induced HT-29 cell death. These results suggest that m- and ${\mu}$-calpain may be involved in colon epithelial cell death induced by E. histolytica.

• 대한한방부인과학회지
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• 제19권2호
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• pp.77-91
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• 2006

Purpose : To address the ability of Dohaekseungkitang (DST: a commonly used herb formulation in Korea, Japan and China to have anti-cancer effect on cervical carcinoma), we investigated the effects of DST on programmed cell death (apoptosis) in HeLa human cervical carcinoma cells. Methods : We cultured HeLa cell which is human metrocarcinoma cell in D-MEM included 10% fetal bovine serum(Hyclone Laboratories) below $37^{\circ}C$, 5% CO2. Then we observed apoptosis of log phage cell which is changed cultivation liquid 24 Hours periodically. Results : After the treatment of DST for 48 hours, apoptosis occurred in a dose-dependent manner. In this study, we have shown that DST induces calpain and the associated caspase-8 and -9 activations. Apoptosis was prevented by pre-incubation of the cells with the calcium cHeLator-BAPTA-AM, calcium channel blocker-Nif edipine or Ryonidine agonist-Ryonidine peptide, implicating calcium in the apoptotic process. Ubiquitous calpains (mu- and m-calpain) have been repeatedly implicated in apoptosis, especially in calcium-related apoptosis. However this study showed 1hat either calpain inhibitor-calpastin or caspase-3 inhibitor-DEVD- did not blocked the herb formulation-induced apoptosis in HeLa human cervical carcinoma cells. D ST initiates a cell death pathway that is partially dependent of caspases. DST-induced apoptosis requires caspase-independent mechanism. Conclusion : We conclude that DST-induced calpain activation triggers the intrinsic apoptotic pathway in which caspase-independent mechanism is also involved.

• 한국축산식품학회지
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• 제25권3호
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• pp.310-315
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• 2005

본 연구는 한우고기의 품질에 영향을 미치는 사후 대사변화를 구명하고자 사후 1, 3, 9, 24시간별에 따라 한우 거세우 배최장근의 pH, 도체온도, R-value 및 단백질분해효소 활성측정을 수행하였다. 도체 pH와 온도는 사후 시간이 경과함에 따라 유의적으로 감소하였고(p<0.05), 사후 3시간에 6.50($31.99^{\circ}C$)을 나타내었다. $R_{248}$과 $R_{250}$ 값은 사후 9시간부터 유의적으로 증가하였지만, $R_{258}$ 값은 사후 9시간부터 감소하였다(p<0.05). Calpain I 활성은 사후 3시간부터 유의적으로 감소하였고, calpastatin 활성은 사후 9시간부터 유의적으로 감소하였다(p<0.05). pH와 도체온도는 $R_{258}$, calpain I, calpastatin에서 0.95이상의 높은 정의 상관관계를 나타내었지만, $R_{248}$과 $R_{250}$에서는 -0.97 이상의 부의 상관관계를 보였다. 이상의 결과를 종합하면, 사후9시간 이후에 대사 변화가 급격히 발생하는 것으로 나타났고, pH와 도체온도의 상관도가 높아 잠재적인 연화능력의 예측이 가능할 것으로 사료되지만, 사후 3시간부터 9시간 사이의 대사변화에 대하여 좀 더 심도 깊은 연구할 필요가 있을 것으로 생각된다.