Progressive histological and behavioral deterioration of a novel mouse model of secondary hydrocephalus after subarachnoid hemorrhage.

Xuehai Deng, Jianlin Ding, Chang Liu, Zhong Wang, Junchi Wang, Qiyue Duan, Weida Li, Xinlong Chen, Xiaoping Tang & Long Zhao.Scientific reports, 30 December 2024

https://doi.org/10.1038/s41598-024-82843-4

Figure 3. Progressive ventricular dilatation and ventricular injury in mice on day 28 after SAH

Abstract:

Hydrocephalus commonly occurs after subarachnoid hemorrhage (SAH) and is associated with increased morbidity and disability in patients with SAH. Choroid plexus cerebrospinal fl

uid (CSF) hypersecretion, obliterative arachnoiditis occluding the arachnoid villi, lymphatic obstruction, subarachnoid fibrosis, and glymphatic system injury are considered the main pathological mechanisms of hydrocephalus after SAH. Although the mechanisms of hydrocephalus after SAH are increasingly being revealed, the clinical prognosis of SAH still has not improved significantly. Further research on SAH is needed to reveal the underlying mechanisms of hydrocephalus and develop translatable therapies. A model that can stably mimic the histopathological and neuroethological features of hydrocephalus is critical for animal experiments. There have been fewer animal studies on hydrocephalus after SAH than on other stroke subtypes. The development of a reproducible and effective model of hydrocephalus after SAH is essential. In this study, we establish a mouse model of SAH that stably mimics brain injury and hydrocephalus after SAH through injections of autologous blood into the cisterna magna via different methods and characterize the model in terms of neurological behavior, histology, imaging, neuronal damage, and white matter damage.

한글 초록 요약본:

 지주막하출혈 (SAH) 이후 발생하는 수두증은 높은 이환율 (morbidity), 장애율 (disability)과 관련되어 있음. 기존에는 SAH 후 수두증의 병태기전을 설명하는 다양한 이론들이 제시되었으나, 아직도 효과적인 치료법이 부족한 실정임. 본 연구에서는 자가혈 (autologous blood)을 대후두조 (cisterna magna)로 주입하여 SAH 및 수두증을 유발하는 새로운 생쥐 모델을 확립하고, 이를 신경행독학, 조직병리, 영상학, 세포 수준에서 체계적으로 평가함. 특히, 90ul 단일 혈액주입군 (Single 90 group)이 가장 뚜렷한 수두증 증상과 조직 손상을 보였으며, 기존 모델에 비해 재현성이 높고 생존율도 양호함. 이 모델은 SAH 이후 수두증의 병태생리를 이해하고 치료법을 개발하는 데 유용한 전임상 도구가 될 수 있음.  

한글 논문 요약본 (Intro, Methods, Results)

1) Introduction: 지주막하출혈 (SAH)은 전체 뇌졸중의 2~7%를 차지하는 질환으로, 높은 사망률과 이환율을 보임. 생존자 중 상당수가 수두증과 같은 2차 합병증을 겪으며, 이는 삶의 질을 크게 저하시킴. 수두증은 뇌실 확장, 뇌압 상승, 백질 손상 등을 유발하며, 장기적으로 인지 및 운동 기능에 악영향을 미침. 이러한 병태기전을 모사할 수 있는 신뢰성 높은 동물 모델은 아직 부족하며, 본 연구는 보다 재현성이 높고 병태학적 특징이 뚜렷한 SAH-후 수두증 생쥐 모델을 개발하고자 함.

2) Methods

 C57BL/6 male mouse (총 251마리)를 대상으로 실험을 수행하였으며, 다음과 같은 네 그룹으로 나뉨.

l  Sham 그룹 (시술만 진행, 혈액 주입 없음)

l  Single 60 group (60ul autologous blood 주입)

l  Single 90 group (90ul autologous blood 주입)

l  Double group (60ul + 24시간 후 30ul 추가 주입)

 모든 그룹에 대해 SAH 점수, MRI (evans ratio, 뇌실 용적), 행동학적 평가 (Garcia 점수, Morris water maze), 조직학 (H&E, Nissl, TUNEL), 전자현미경, Western blot 등을 수행하여 수두증 발생률, 조직 손상 및 관련 단백질 발현을 평가함.

3) Results

3-1) 모델 확립 및 생존율: Single 90 group의 사망률은 7.04%로 낮았으며, SAH 점수는 다른 그룹 대비 가장 높았음.

3-2) 영상 및 조직학적 변화: MRI 상에서 Single 90 group은 3일 및 28일 모두에서 가장 심한 뇌실 확장을 보였고, 조직학적으로 뇌실벽 손상 및 염증세포 침윤이 두드러짐.

3-3) 신경세포 손상: TUNEL 및 Nissl 염색 결과, Single 90 group에서 신경세포 수축과 괴사/ 사멸이 가장 많이 관찰됨.

3-4) 백질 손상: MBP 면역염색 및 은 염색, TEM 분석에서 Single 90 group의 백질 (특히 뇌량) 손상이 가장 심각했으며, myelin 붕괴 및 축삭 손상이 관찰됨.

3-5) 행동학적 이상: Garcia 점수 및 Morris water maze 시험에서 Single 90 group은 지속적인 신경학적 결손과 인지 기능 저하를 보임.

3-6) 단백질 발현: TGF-β1, p-Smad2/3, p38, CTGF, AQP4 등의 수두증 연관 단백질이 Single 90 group에서 가장 높게 발현함.