Profiling Temporal Changes of the Pineal Transcriptomes at Single Cell Level Upon Neonatal HIBD

Xin Ding; Tao Pan; Qiuyan Tian; Wenxi Huang; Lauren S Hayashi; Qin Liu; Fuyong Li; Li-Xiao Xu; Po Miao; Xiaofeng Yang; Bin Sun; Chen-Xi Feng; Xing Feng; Mei Li; Jian Huang

doi:10.3389/fcell.2022.794012

Profiling Temporal Changes of the Pineal Transcriptomes at Single Cell Level Upon Neonatal HIBD

Front Cell Dev Biol. 2022 Mar 8:10:794012. doi: 10.3389/fcell.2022.794012. eCollection 2022.

Authors

Xin Ding¹, Tao Pan¹, Qiuyan Tian², Wenxi Huang³, Lauren S Hayashi⁴, Qin Liu², Fuyong Li², Li-Xiao Xu², Po Miao¹, Xiaofeng Yang¹, Bin Sun¹, Chen-Xi Feng², Xing Feng^{1

2

3

4

5}, Mei Li², Jian Huang⁵

Affiliations

¹ Soochow Key Laboratory of Prevention and Treatment of Child Brain Injury, Children's Hospital of Soochow University, Suzhou, China.
² Pediatrics Research Institute, Children's Hospital of Soochow University, Suzhou, China.
³ Undergraduate Program, University of Virginia, Charlottesville, VA, United States.
⁴ IRTA Fellow, National Institutes of Health, Bethesda, MD, United States.
⁵ School of Basic Medicine and Biological Sciences, Medical College of Soochow University, Suzhou, China.

Abstract

Neonatal hypoxic-ischemic brain damage (HIBD) often results in various neurological deficits. Among them, a common, yet often neglected, symptom is circadian rhythm disorders. Previous studies revealed that the occurrence of cysts in the pineal gland, an organ known to regulate circadian rhythm, is associated with circadian problems in children with HIBD. However, the underlying mechanisms of pineal dependent dysfunctions post HIBD remain largely elusive. Here, by performing 10x single cell RNA sequencing, we firstly molecularly identified distinct pineal cell types and explored their transcriptome changes at single cell level at 24 and 72 h post neonatal HIBD. Bioinformatic analysis of cell prioritization showed that both subtypes of pinealocytes, the predominant component of the pineal gland, were mostly affected. We then went further to investigate how distinct pineal cell types responded to neonatal HIBD. Within pinealocytes, we revealed a molecularly defined β to α subtype conversion induced by neonatal HIBD. Within astrocytes, we discovered that all three subtypes responded to neonatal HIBD, with differential expression of reactive astrocytes markers. Two subtypes of microglia cells were both activated by HIBD, marked by up-regulation of Ccl3. Notably, microglia cells showed substantial reduction at 72 h post HIBD. Further investigation revealed that pyroptosis preferentially occurred in pineal microglia through NLRP3-Caspase-1-GSDMD signaling pathway. Taken together, our results delineated temporal changes of molecular and cellular events occurring in the pineal gland following neonatal HIBD. By revealing pyroptosis in the pineal gland, our study also provided potential therapeutic targets for preventing extravasation of pineal pathology and thus improving circadian rhythm dysfunction in neonates with HIBD.

Keywords: astrocyte; hypoxic-ischemic brain damage; microglia; pineal gland; pinealocyte; pyroptosis; single cell RNA sequencing.