Ming Luo,1â 3 Yang Wang,1â 3 Xiaohang Guo,1â 3 Weikang Luo,1â 3 Zhiqiang Yuan,1â 3 Xueping Yang,1â 3 Xudong Fan,1â 3 Zhaoyu Yang,1â 3 Tao Tang1â 3 1Department of Integrated Traditional Chinese and Western Medicine, Institute of Integrative Medicine, Xiangya Hospital, Central South University, Changsha, 410008, Peopleâs Republic of China; 2Center for Interdisciplinary Research in Traditional Chinese Medicine, Xiangya Hospital, Central South University, Changsha, 410008, Peopleâs Republic of China; 3National Clinical Research Center for Geriatric Disease, Xiangya Hospital, Central South University, Changsha, 410008, Peopleâs Republic of ChinaCorrespondence: Tao Tang; Zhaoyu Yang, Department of Integrated Traditional Chinese and Western Medicine, Institute of Integrative Medicine, Xiangya Hospital, Central South University, Changsha, 410008, Peopleâs Republic of China, Email tangtaotay@csu.edu.cn; zhyangzoe@csu.edu.cnPurpose: Traumatic brain injury (TBI) triggers profound neuroinflammatory responses; however, the regulatory role of small nucleolar RNAs (snoRNAs) in TBI-associated neuroinflammation remains poorly understood. This study evaluated its prognostic value in TBI.Mice and Methods: A controlled cortical impact (CCI) model was established in male C57BL/6 mice and validated through modified neurological severity scoring (mNSS), hematoxylin-eosin (H&E) staining, and immunostaining for IgG leakage and Nissl substance. Cortical snoRNA expression profiles were assessed using microarray analysis, with differentially expressed candidates confirmed by quantitative real-time PCR (qRT-PCR). The spatial distribution of snoRNAs was determined via fluorescence in situ hybridization (FISH), while the anti-inflammatory effects of snoRNA Gm24418 were evaluated in vivo and vitro. Downstream molecular pathways were identified through transcriptomic sequencing combined with bioinformatics analysis.Results: Mice subjected to CCI exhibited significant motor and cognitive impairments (elevated mNSS), neuronal loss (as indicated by H&E and Nissl staining), and blood-brain barrier disruption (evidenced by IgG extravasation). Microarray analysis identified 47 dysregulated small nucleolar RNAs (snoRNAs), comprising 43 that were downregulated and 4 that were upregulated, with Gm24418 exhibiting the most significant downregulation. FISH confirmed the localization of Gm24418 predominantly in cortical neurons. Overexpression of Gm24418 in N2A cells and mice significantly reduced the levels of pro-inflammatory cytokines, including IL-1β, TNF-α, and IL-6, and suppressed the activation of Ccl2 and TNF signaling pathways. Mechanistic analyses indicated that Gm24418 overexpression is associated with downregulation of the TNF signaling pathway, thereby attenuating neuroinflammation and promoting the restoration of blood-brain barrier integrity following TBI.Conclusion: Gm24418 is identified as a neuron-specific snoRNA that ameliorates TBI-induced neuropathology through influencing the expression of key inflammatory mediators, including CCL2 and TNF-α, representing a promising novel therapeutic target for post-traumatic neuroinflammation. At the top, Gm24418 DNA is transcribed into pre-snoRNA, which is processed into C/D box snoRNA and H/ACA box snoRNA. These snoRNAs form snoRNP complexes. The diagram is divided into two sections: low snoRNP level and high snoRNP level. In the low snoRNP level section, Gm24418 snoRNP is shown interacting with CCL2, leading to a pro-inflammatory phenotype with increased TNF alpha, IL-1 beta and IL-6. In the high snoRNP level section, multiple Gm24418 snoRNP complexes interact with CCL2, resulting in an anti-inflammatory phenotype with decreased TNF alpha, IL-1 beta and IL-6. Arrows indicate the direction of snoRNA processing and the effects on inflammatory phenotypes.Diagram showing Gm24418 snoRNA processing, snoRNP levels and their effects on inflammatory phenotypes.Keywords: traumatic brain injury, bioinformatics analysis, small RNA microarray profiling, RNA-seq, neuroinflammation, biomarkers
Luo et al. (Wed,) studied this question.