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Kao SY, Katsumi S, Han D, Bizaki-Vallaskangas AJ, Vasilijic S, Landegger LD, Kristiansen AG, McKenna MJ, Stankovic KM. Postnatal expression and possible function of RANK and RANKL in the murine inner ear. Bone 2021; 145:115837. [PMID: 33385614 DOI: 10.1016/j.bone.2020.115837] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 11/28/2020] [Accepted: 12/23/2020] [Indexed: 12/20/2022]
Abstract
The bone encasing the inner ear, known as the otic capsule, is unique because it remodels little postnatally compared to other bones in the body. Previous studies established that osteoprotegerin (OPG) in the inner ear inhibits otic capsule remodeling. OPG acts as a decoy receptor of receptor activator of nuclear factor κB ligand (RANKL) to disrupt the interaction between RANKL and RANK, the primary regulators of bone metabolism. Here we studied the expression and function of RANK and RANKL in the murine cochlea. Using a combination of in situ hybridization, real-time quantitative RT-PCR, and western blot, we demonstrate that Rankl and Rank genes and their protein products are expressed in the intracochlear soft tissues and the otic capsule in a developmentally regulated manner. Using a culture of neonatal murine cochlear neurons, we show that the interaction between RANK and RANKL inhibits neurite outgrowth in these neurons, and is associated with upregulation of NOGO-A expression. Taken together, our results suggest that, in addition to regulating otic capsule bone remodeling, RANK and RANKL expressed by intracochlear soft tissues may also regulate spiral ganglion neuron function by affecting neurite outgrowth.
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Affiliation(s)
- Shyan-Yuan Kao
- Department of Otolaryngology - Head and Neck Surgery, Massachusetts Eye and Ear, Boston, MA 02114, USA
| | - Sachiyo Katsumi
- Department of Otolaryngology - Head and Neck Surgery, Massachusetts Eye and Ear, Boston, MA 02114, USA; Department of Otolaryngology - Head and Neck Surgery, Harvard Medical School, Boston, MA 02115, USA
| | - Dongjun Han
- Department of Otolaryngology - Head and Neck Surgery, Massachusetts Eye and Ear, Boston, MA 02114, USA; Department of Otolaryngology - Head and Neck Surgery, Harvard Medical School, Boston, MA 02115, USA
| | | | - Sasa Vasilijic
- Department of Otolaryngology - Head and Neck Surgery, Massachusetts Eye and Ear, Boston, MA 02114, USA; Department of Otolaryngology - Head and Neck Surgery, Harvard Medical School, Boston, MA 02115, USA
| | - Lukas D Landegger
- Department of Otolaryngology - Head and Neck Surgery, Massachusetts Eye and Ear, Boston, MA 02114, USA; Department of Otolaryngology - Head and Neck Surgery, Harvard Medical School, Boston, MA 02115, USA
| | - Arthur G Kristiansen
- Department of Otolaryngology - Head and Neck Surgery, Massachusetts Eye and Ear, Boston, MA 02114, USA
| | - Michael J McKenna
- Department of Otolaryngology - Head and Neck Surgery, Massachusetts Eye and Ear, Boston, MA 02114, USA; Department of Otolaryngology - Head and Neck Surgery, Harvard Medical School, Boston, MA 02115, USA; Speech and Hearing Bioscience and Technology Program, Harvard Medical School, Boston, MA 02115, USA
| | - Konstantina M Stankovic
- Department of Otolaryngology - Head and Neck Surgery, Massachusetts Eye and Ear, Boston, MA 02114, USA; Department of Otolaryngology - Head and Neck Surgery, Harvard Medical School, Boston, MA 02115, USA; Speech and Hearing Bioscience and Technology Program, Harvard Medical School, Boston, MA 02115, USA; Harvard Stem Cell Institute, Cambridge, MA 02138, USA; Program in Therapeutic Science, Harvard Medical School, Boston, MA 02115, USA.
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Force-induced decline of TEA domain family member 1 contributes to osteoclastogenesis via regulation of Osteoprotegerin. Arch Oral Biol 2019; 100:23-32. [PMID: 30771694 DOI: 10.1016/j.archoralbio.2019.01.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 01/28/2019] [Accepted: 01/30/2019] [Indexed: 01/06/2023]
Abstract
OBJECTIVE This study aims to investigate the responsiveness of transcription factor TEA domain family member 1 (TEAD1) to mechanical force and its impact on osteoclastogenesis as well as expression of Osteoprotegerin (OPG), an inhibitor for osteoclastogenesis playing crucial roles in mechanical stress-induced bone remodeling and orthodontic tooth movement (OTM). METHODS We first analyzed the correlation between several transcription factors and OPG expression in human periodontal ligament cells (PDLCs). Then dynamic expression changes of TEAD1 with force application were analyzed due to its high correlation with OPG. Loss-of-function experiments were performed to demonstrate the role of TEAD1 in regulation of RANKL/OPG, as well as osteoclastogenesis by tartrate-resistant acid phosphatase (TRAP) staining. Combination of bioinformatics analyzes and chromatin immunoprecipitation assay was utilized to investigate occupancy of TEAD1 on the enhancer elements of OPG and the dynamic change in response to force stimuli. Involvement of Hippo signaling in regulation of OPG was further demonstrated by pharmacologic inhibitors of several components. RESULTS Expression of TEAD1 highly correlates with that of OPG and decreases in response to mechanical force in human PDLCs. Knockdown of TEAD1 downregulates expression of OPG and promotes osteoclast differentiation. Mechanical force induced decreased binding of TEAD1 on an enhancer element ˜22 kilobases upstream of OPG promoter. OPG was also affected by pharmaceutical disruption of Hippo signaling pathway. CONCLUSIONS TEAD1 is a novel mechano-responsive gene and plays an important role in force-induced osteoclastogenesis, which is dependent, as least partially, on transcriptional regulation of OPG.
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