突發神經性耳聾病患 周邊血液白血球之 日夜節律基因表現變化 Altered expression of circadian clock genes in peripheral blood leukocytes of patients with sudden sensorineural hearing loss 楊昭輝1,2 楊敏瑜2 黃仲鋒1 [1]高雄長庚醫院耳鼻喉科 [2]長庚大學臨床醫學研究所

Circadian rhythm Endogenous oscillations in organisms that were observed in approximate association with the daily rotation cycle of the Earth. Daily rhythmic changes are found in many physiological processes, including sleep, appetite, hormone level, metabolism, and gene expression. 日夜節律存在於每個在地球上的生物體，藉由日夜周期來調控生理功能。 Young and Kay, 2001

Light is processed through the eye and is transmitted via the retinohypothalamic tract to neurons of the suprachiasmatic nuclei (SCN) in the hypothalamus. 日夜節律是由誰來控制呢? 最主要是光線進去我們的眼睛，會傳遞訊號藉由retinohypothalamic tract 傳到下視丘的suprachiasmatic nuclei (SCN) 的這個構造，這個SCN就像我們身體裡的時鐘，除了是central pacemaker之外，也能進一步發出訊息給身體周邊的器官，例如肺臟、心臟、肝臟等等，而讓周邊的組織也有日夜節律的現象。 Hypothalamic–pituitary–adrenal (HPA) axis

Circadian clock genes (CCGs) 那身體的生理時鐘如何被調控呢? 最主要的是靠一些基因，我們稱作Circadian clock genes。這些基因有所feedback loop(轉錄-轉譯反饋迴路)，產生transcription factor在不同時間上升及下降，造成我們身體的其他基因也有日夜節律的現象，造就生物體的生理時鐘。

For their discoveries of molecular mechanisms that control circadian rhythms

Circadian rhythm in inner ear In the inner ear, diurnal changes of otoacoustic emissions of outer hair cells in the cochlea have been reported (Wit et al, 1985) Presence of circadian oscillation in the inner ear. (Meltser et al, 2014) Mice have different threshold shifts in response to noise at day and night. (Meltser et al, 2014) A statistically significant frequency decrease during the morning hours was observed for both subjects

Alteration of circadian clock genes (CCGs) in mental and neurodegenerative disorders Parkinson’s disease Bipolar disorder Depression

Stress affects circadian rhythm in mice https://www.waseda.jp/top/en- news/28579. Yu, et al. 2015

Biopsychosocial model Hoffmeister et al. 1988 ; Claudia et al. 2000

Objectives To survey the expression of CCGS in sudden sensorineural hearing loss (SSNHL) patients and healthy control To compared the expression of CCGs in SSNHL patients with different severity of disease To compared the expression of CCGs in SSNHL patients with different quality of sleep

Methods It is proved that CCGs expression in morning PB leukocytes can reflect the peak of circadian rhythm of the body. (Yang et al, 2001; Kusanagi et al, 2008) Peripheral blood (PB) samples were collected from SSNHL patients before steroid treatment and from normal controls in the morning (8:00-9:00am). mRNA were obtained from PB leukocytes of each subject. Sleep questionnaire was gathered in SSNHL patients to investigate the quality of sleep

Expression of circadian clock genes (CCGs)

CCGs gene expression and disease severity of SSNHL

Immunocytochemistry in circadian clock genes

Sleep questionnaire

CCGs gene expression and quality of sleep in SSNHL patients

Possible explanation 1: Dysregulation of circadian corticosteroid peak in the inner ear Daily corticosteroid peak in mammals achieved by hypothalamic–pituitary–adrenal (HPA) axis. Because corticosteroid is essential in keeping homeostatic balance of inner ear, altered circadian rhythm may cause dysregulation of circadian corticosteroid peak in the body, and in turn affect the function of inner ear. 我們知道corticosteroid是影響內耳生理機能恆定很重要的腳色，日夜節律的改變會影響控制cot Kalsbeek et al, 2012

Possible explanation 2 : Dysregulation of the immune system and affect the stress response in the inner ear Stress response theory of SSNHL: systemic viral illness, inflammatory disorder, and mental or metabolic stress may induce immunity, which will result in the activation of NF-kB in the cochlea When patients suffered from ‘‘common cold,’’ sleep disturbance may disturbed the circadian rhythm in immune system, and strengthen the inflammatory stress response in the cochlea, which then cause a ‘‘second hit’’ upon the inner ear. Merchant et al, 2008

Conclusion Our results of this study present the association of altered expression of CCGs in peripheral leukocytes of patients with SSNHL. Decreased expression of circadian clock genesis more obviously found in SSNHL patients with vertigo. Future investigation : Circadian disruption in inner ear disorders

Thanks for your attention! 高雄長庚醫院耳鼻喉科 楊昭輝 chouwhay@gmail.com