Downregulation of osteopontin in the mouse salivary gland after X-ray irradiation

Autor: Gen-yuki Yamane, Kazumasa Ohta, Harutoshi Kizaki, Morio Tonogi, Sachiko Takaki, Yasuhiro Kizu
Rok vydání: 2012
Předmět:
Zdroj: Oral Radiology. 28:75-81
ISSN: 1613-9674
0911-6028
DOI: 10.1007/s11282-012-0089-x
Popis: Radiation-induced xerostomia is a frequent consequence of radiotherapy for head and neck cancer, but its mechanisms remain unclear. Osteopontin (OPN), a highly phosphorylated glycoprotein, has been shown to be involved in the modulation of inflammatory and tissue repair processes and to be expressed in the salivary gland. In this study, using a murine model of radiation-induced xerostomia, expression of OPN in the mouse sublingual gland (SLG) and submandibular gland (SMG) after irradiation was determined by quantitative RT-PCR (qRT-PCR) and western blotting. To explore the cellular location of OPN and its relationships with matrix metalloproteinase 3 (MMP3)-positive and CD11b-positive cells, both of which are also involved in radiation-induced tissue responses, immunofluorescence analysis was performed with anti-OPN, anti-MMP3, and anti-CD11b antibodies. In both the SLG and SMG, a transient increase in OPN mRNA expression was observed on day 5 post-irradiation; this subsequently decreased by day 10 post-irradiation. Western blotting and immunofluorescence analysis revealed downregulation of OPN and MMP3 in duct cells on day 10 post-irradiation, whereas CD11b-positive cells, which were not detected in non-irradiated mice, were increased in the stroma after irradiation. The downregulation of OPN and MMP3, together with the concomitant increase in CD11b-positive cells, may modulate radiation-induced inflammatory responses, resulting in salivary gland dysfunction at a later stage after irradiation.
Databáze: OpenAIRE
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