Browsing by Author "Arima, Kazuhiko"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Constitutive overexpression of periostin delays wound healing in mouse skin
    (Wiley, 2018) Nunomura, Satoshi; Nanri, Yasuhiro; Ogawa, Masahiro; Arima, Kazuhiko; Mitamura, Yasutaka; Yoshihara, Tomohito; Hasuwa, Hidetoshi; Conway, Simon J.; Izuhara, Kenji; Pediatrics, School of Medicine
    Periostin is a matricellular protein involved in development, maintenance and regulation of tissues and organs via by binding to cell surface integrin receptors. Pathologically, periostin plays an important role in the process of wound healing: as a deficiency of the Postn gene delays wound closure and periostin is consistently upregulated in response to injury and skin diseases. However, the functional role of elevated periostin in the process of wound healing has not been tested. In this study, we generated Postn-transgenic mice under the control of the CAG promoter/enhancer to investigate the effects of constitutive overexpression of full length periostin during its pathophysiological roles. Transgenic mice showed significant overexpression of periostin in skin, lung, and heart, but no morphological changes were observed. However, when these transgenic mice were injured, periostin overexpression delayed the closure of excisional wounds. Expression of IL-1β and TNFα, pro-inflammatory cytokines important for wound healing, was significantly decreased in the transgenic mice, prior to delayed healing. Infiltration of neutrophils and macrophages, the main sources of IL-1β and TNFα, was also downregulated in the transgenic wound sites. From these data, we conclude that enforced expression of periostin delays wound closure due to reduced infiltration of neutrophils and macrophages followed by downregulation of IL-1β and TNFα expression. This suggests that regulated spatiotemporal expression of periostin is important for efficient wound healing and that constitutive periostin overexpression interrupts the normal process of wound closure.
  • Thumbnail Image
    Item
    Periostin, a matricellular protein, plays a role in the induction of chemokines in pulmonary fibrosis
    (American Thoracic Society, 2012-05) Uchida, Masaru; Shiraishi, Hiroshi; Ohta, Shoichiro; Arima, Kazuhiko; Taniguchi, Kazuto; Suzuki, Shoichi; Okamoto, Masaki; Ahlfeld, Shawn K.; Ohshima, Koichi; Kato, Seiya; Toda, Shuji; Sagara, Hironori; Aizawa, Hisamichi; Hoshino, Tomoaki; Conway, Simon J.; Hayashi, Shinichiro; Izuhara, Kenji; Department of Pediatrics, IU School of Medicine
    Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and usually fatal form of interstitial lung disease (ILD). The precise molecular mechanisms of IPF remain poorly understood. However, analyses of mice receiving bleomycin (BLM) as a model of IPF established the importance of preceding inflammation for the formation of fibrosis. Periostin is a recently characterized matricellular protein involved in modulating cell functions. We recently found that periostin is highly expressed in the lung tissue of patients with IPF, suggesting that it may play a role in the process of pulmonary fibrosis. To explore this possibility, we administered BLM to periostin-deficient mice, and they subsequently showed a reduction of pulmonary fibrosis. We next determined whether this result was caused by a decrease in the preceding recruitment of neutrophils and macrophages in the lungs because of the lower production of chemokines and proinflammatory cytokines. We performed an in vitro analysis of chemokine production in lung fibroblasts, which indicated that periostin-deficient fibroblasts produced few or no chemokines in response to TNF-α compared with control samples, at least partly explaining the lack of inflammatory response and, therefore, fibrosis after BLM administration to periostin-deficient mice. In addition, we confirmed that periostin is highly expressed in the lung tissue of chemotherapeutic-agent-induced ILD as well as of patients with IPF. Taking these results together, we conclude that periostin plays a unique role as an inducer of chemokines to recruit neutrophils and macrophages important in the process of pulmonary fibrosis in BLM-administered model mice. Our results suggest a therapeutic potential for periostin in IPF and drug-induced ILD.