Identification of ETFB as a candidate protein that participates in the mechanoregulation of fibroblast cell number in collagen gel culture
JOURNAL OF DERMATOLOGICAL SCIENCE
Authors: Hirokawa, Shigenari; Shimanuki, Tomomasa; Kitajima, Hiroyuki; Nishimori, Yasutomo; Shimosaka, Makoto
Abstract
Background: Fibroblast activation is strongly influenced by mechanical environment in the wound-healing process, especially in fibrosis. Mechanically stressed three-dimensional collagen embedded culture is a useful model representing fibroblasts in morphological as well as biochemical situations encountered during fibrosis. Objective: To find key proteins involved in reducing the number of fibroblasts during mechanical stress, we performed two-dimensional gel electrophoresis (2DE)-based differential display and siRNA-based functional screening with collagen gel culture focusing on the differences between attached and detached culture environments. Methods: Membrane extracts of fibroblasts from 1 day of attached or detached cultures were subjected to 2DE. We compared protein expression levels and identified the attached-culture-dominant proteins by MALDI-TOF-MS. Next, fibroblasts were transfected with siRNA and embedded in collagen gel. Cell number was counted after 3 days in culture. Results: Eight attached culture dominant proteins were identified with MALDI-TOF-MS. Transfection of siRNA against these proteins demonstrated that electron transfer flavoprotein 13 subunit (ETFB)-specific siRNA reduced the cell number in the attached culture without a decrease in the detached culture. Conclusion: ETFB participates in the mechanoregulation of fibroblast cell number in collagen gel culture. (C) 2011 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.
CLINICAL AND GENETIC ANALYSIS OF LIPID STORAGE MYOPATHIES
MUSCLE & NERVE
Authors: Ohkuma, Aya; Noguchi, Satoru; Sugie, Hideo; Malicdan, May Christine V.; Fukuda, Tokiko; Shimazu, Kunio; Lopez, Luis Carlos; Hirano, Michio; Hayashi, Yukiko K.; Nonaka, Ikuya; Nishino, Ichizo
Abstract
Causative genes have been identified only in four types of lipid storage myopathies (LSMs): SLC22A5 for primary carnitine deficiency (PCD); ETFA, ETFB, and ETFDH for multiple acyl-coenzyme A dehydrogenation deficiency (MADD); PNPLA2 for neutral lipid storage disease with myopathy (NLSDM); and ABHD5 for neutral lipid storage disease with ichthyosis. However, the frequency of these LSMs has not been determined. We found mutations in only 9 of 37 LSM patients (24%): 3 in SLC22A5; 4 in MADD-associated genes; and 2 in PNPLA2. This low frequency suggests the existence of other causative genes. Muscle coenzyme Q,, levels were normal or only mildly reduced in two MADD patients, indicating that ETFDH mutations may not always be associated with CoQ(10) deficiency. The 2 patients with PNPLA2 mutations had progressive, non-episodic muscle disease with rimmed vacuoles. This suggests there is a different pathomechanism from other LSMs. Muscle Nerve 39: 333-342, 2009