HISTOLOGY AND HISTOPATHOLOGY

From Cell Biology to Tissue Engineering

 

The distribution and time-dependent expression of HIPK2 during the repair of contused skeletal muscle in mice

Miao Zhang1,2,3*, Meng-Zhou Zhang1*, Shu-Heng Wen1, Ying-Fu Sun1, Peng-Hao Jiang1, Lin-Lin Wang1,2,3, Rui Zhao1,2,3, Chang-Liang Wang1,2, Shu-Kun Jiang1,2,3 and Da-Wei Guan1,2,3

1Department of Forensic Pathology, China Medical University School of Forensic Medicine, Liaoning Province, 2Collaborative Laboratory of Intelligentized Forensic Science (CLIFS) and 3Remote Forensic Consultation Center, Collaborative Innovation Center of Judicial Civilization, China University of Political Science and Law, Beijing, P.R. China
*These authors have contributed equally to this work

Offprint requests to: Shu-Kun Jiang or Da-Wei Guan, Department of Forensic Pathology, China Medical University School of Forensic Medicine, Liaoning Proviince, P.R. China. e-mail: skjiang@cmu.edu.cn or dwguan@cmu.edu.cn


Summary. HIPK2 is an evolutionarily conserved serine/threonine kinase and is considered a co-regulator of an increasing number of transcription factors modulating a variety of cellular processes, including inflammation, proliferation and fibrosis. Skeletal muscle injuries repair is an overlapping event between inflammation and tissue repair. There are no reports about HIPK2 expression in skeletal muscles after trauma. A foundational study on distribution and time-dependent expression of HIPK2 was performed by immunohistochemical staining, Western blotting and quantitative real-time PCR, which is expected to obtain a preliminary insight into the functions of HIPK2 during the repair of contused skeletal muscle in mice. An animal model of skeletal muscle contusion was established in 50 C57B6/L male mice. Samples were taken at 1, 3, 5, 7, 9, 14, 17, 21 and 28 days after contusion, respectively (5 mice at each posttraumatic interval). 5 mice were employed as control. No HIPK2-positive staining was detected in uninjured skeletal muscle. Intensive immunoreactivties of HIPK2 were observed in polymorphonuclear cells, round-shaped mononuclear cells, regenerated multinucleated myotubes and spindle-shaped fibroblastic cells in the contused tissue. The HIPK2-positive cells were identified as neutrophils, macrophages and myofibroblasts by double immunofluorescent procedure. HIPK2 protein and mRNA expression were remarkably up-regulated after contusion by Western blotting and qPCR analysis. The results demonstrated that the expression of HIPK2 is distributed in certain cell types and is time-dependently expressed in skeletal muscle after contusion, which suggested that HIPK2 may participate in the whole process of skeletal muscle wound healing, including inflammatory response, muscle regeneration and fibrogenesis. Histol Histopathol 34, 745-753 (2019)

Key words: HIPK2, Skeletal muscle, Wound repair, Trauma

DOI: 10.14670/HH-18-072