» Articles » PMID: 26696743

Alteration of Cathepsin-D Expression in Atrophied Muscles and Apoptotic Myofibers by Hindlimb Unloading in a Low-temperature Environment

Overview
Journal J Phys Ther Sci
Date 2015 Dec 24
PMID 26696743
Citations 2
Authors
Affiliations
Soon will be listed here.
Abstract

[Purpose] The purpose of this study was to elucidate the cathepsin-D involvement in signaling pathways for the survival and apoptosis of myofibers in rats with hindlimb-unloading in a low-temperature environment. [Subjects and Methods] Wistar rats were divided into two groups: a control group and a group that underwent hindlimb unloading in a low-temperature environment to induce muscle apoptosis. Cathepsin-D localization in the soleus and extensor digitorum longus muscles, along with the expression of cathepsin-D in apoptotic myofibers, was examined. Expression of the active and inactive forms of cathepsin-D was also analyzed. [Results] Cathepsin-D was mainly expressed in type I myofibers and was observed to have punctate patterns in the control group. In the hindlimb unloading in a low-temperature environment group, the type I myofiber composition ratio decreased, and caspase-3 activation and TUNEL-positive apoptotic myofibers were observed. In caspase-3-activated myofibers, cathepsin-D overexpression and leakage of it into the cytoplasm were observed. In the hindlimb unloading in a low-temperature environment group, the amount of inactive cathepsin-D decreased, whereas that of the active form increased. [Conclusion] Cathepsin-D was deduced to be indicative of a myofiber-type classification and a factor related to myofiber type maintenance. In addition, cathepsin-D leakage into the cytoplasm was appeared to be involved in caspase-3 activation in the hindlimb unloading in a low-temperature environment group.

Citing Articles

Quantitative analysis of approximate shapes in a myofiber cross-section and their relationship with myofiber cross-sectional area.

Nagano K J Phys Ther Sci. 2021; 33(12):931-934.

PMID: 34873377 PMC: 8636916. DOI: 10.1589/jpts.33.931.


Skeletal Muscle Myofibrillar Protein Abundance Is Higher in Resistance-Trained Men, and Aging in the Absence of Training May Have an Opposite Effect.

Vann C, Roberson P, Osburn S, Mumford P, Romero M, Fox C Sports (Basel). 2020; 8(1).

PMID: 31936810 PMC: 7022975. DOI: 10.3390/sports8010007.

References
1.
Erickson A, Conner G, Blobel G . Biosynthesis of a lysosomal enzyme. Partial structure of two transient and functionally distinct NH2-terminal sequences in cathepsin D. J Biol Chem. 1981; 256(21):11224-31. View

2.
Yoshida N, Ikata T, Sairyo K, Matsuura T, SASA T, Koga K . Evaluation of disuse atrophy of rat skeletal muscle based on muscle energy metabolism assessed by 31P-MRS. J Physiol Anthropol Appl Human Sci. 2001; 20(4):247-52. DOI: 10.2114/jpa.20.247. View

3.
Matsukura U, Matsumoto T, Tashiro Y, Okitani A, Kato H . Morphological changes in myofibrils and glycerinated muscle fibers on treatment with cathepsins D and L. Int J Biochem. 1984; 16(9):957-62. DOI: 10.1016/0020-711x(84)90111-3. View

4.
Schiaffino S, Reggiani C . Fiber types in mammalian skeletal muscles. Physiol Rev. 2011; 91(4):1447-531. DOI: 10.1152/physrev.00031.2010. View

5.
Ashley Z, Sutherland H, Lanmuller H, Russold M, Unger E, Bijak M . Atrophy, but not necrosis, in rabbit skeletal muscle denervated for periods up to one year. Am J Physiol Cell Physiol. 2007; 292(1):C440-51. DOI: 10.1152/ajpcell.00085.2006. View