Ni Ruiqing, Straumann Nadja, Fazio Serana, Dean-Ben Xose Luis, Louloudis Georgios, Keller Claudia, Razansky Daniel, Ametamey Simon, Mu Linjing, Nombela-Arrieta César, Klohs Jan
Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland.
Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, University of Zurich & ETH Zurich, Zurich, Switzerland.
Photoacoustics. 2023 Jul 15;32:100532. doi: 10.1016/j.pacs.2023.100532. eCollection 2023 Aug.
Emerging evidence indicates crosstalk between the brain and hematopoietic system following cerebral ischemia. Here, we investigated metabolism and oxygenation in the spleen and spinal cord in a transient middle cerebral artery occlusion (tMCAO) model. Sham-operated and tMCAO mice underwent [F]fluorodeoxyglucose (FDG)-positron emission tomography (PET) to assess glucose metabolism. Naïve, sham-operated and tMCAO mice underwent multispectral optoacoustic tomography (MSOT) assisted by quantitative model-based reconstruction and unmixing algorithms for accurate mapping of oxygenation patterns in peripheral tissues at 24 h after reperfusion. We found increased [F]FDG uptake and reduced MSOT oxygen saturation, indicating hypoxia in the thoracic spinal cord of tMCAO mice compared with sham-operated mice but not in the spleen. Reduced spleen size was observed in tMCAO mice compared with sham-operated mice . tMCAO led to an increase in the numbers of mature T cells in femoral bone marrow tissues, concomitant with a stark reduction in these cell subsets in the spleen and peripheral blood. The combination of quantitative PET and MSOT thus enabled observation of hypoxia and increased metabolic activity in the spinal cord of tMCAO mice at 24 h after occlusion compared to sham-operated mice.
新出现的证据表明，脑缺血后大脑与造血系统之间存在相互作用。在此，我们在短暂性大脑中动脉闭塞（tMCAO）模型中研究了脾脏和脊髓的代谢及氧合情况。对假手术组和tMCAO组小鼠进行[F]氟脱氧葡萄糖（FDG）正电子发射断层扫描（PET）以评估葡萄糖代谢。对未处理、假手术组和tMCAO组小鼠在再灌注24小时后，采用基于定量模型的重建和分解算法辅助的多光谱光声断层扫描（MSOT），以精确绘制外周组织中的氧合模式。我们发现，与假手术组小鼠相比，tMCAO组小鼠胸段脊髓的[F]FDG摄取增加，MSOT氧饱和度降低，表明存在缺氧，但脾脏中未出现这种情况。与假手术组小鼠相比，tMCAO组小鼠的脾脏尺寸减小。tMCAO导致股骨骨髓组织中成熟T细胞数量增加，同时脾脏和外周血中这些细胞亚群数量大幅减少。因此，与假手术组小鼠相比，定量PET和MSOT相结合能够观察到tMCAO组小鼠在闭塞24小时后脊髓中的缺氧情况及代谢活性增加。
