Multi-dimensional decoding of the TSPO signal in animal models of neuroinflammation using fluorescence-conjugated DPA714 PMID: 42343311

ADC Targets in Oncology

2026-04-10

Multi-dimensional decoding of the TSPO signal in animal models of neuroinflammation using fluorescence-conjugated DPA714

J Neuroinflammation. 2026 Jun 24;23(1):212. doi: 10.1186/s12974-026-03829-9.

Huanhuan Song ^# ¹ ² , Zhibao Zhu ^# ¹ ² , Limei Xiao ^# ¹ , Qiuping Zhao ^# ² , Chun Li ² , Aowei Lv ² , Xintong Yu ² , Zhuyu Gao ³ , Jie Lin ¹ , Youliang Wang ¹ , Yuanyuan Zhang ² , Lijie Zhang ¹ , Runyun Li ² , Shaobo Yao ⁴ , Mengchao Cui ⁵ , Yi Lin ⁶ ⁷ , Ying Fu ⁸ ⁹ , V Wee Yong ¹⁰ , Rui Li ¹¹ ¹²

Affiliations

1. Department of Neurology, Fujian Institute of Neurology, the First Affiliated Hospital of Fujian Medical University, Fujian Medical University, Fuzhou, 350005, China.
2. Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, 350004, China.
3. Department of Neurosurgery, Neurosurgery Research Institute, The First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian, 350005, China.
4. Department of PET/CT Diagnostic, Tianjin Medical University General Hospital, Tianjin, 300052, China.
5. Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, 100875, China.
6. Department of Neurology, Fujian Institute of Neurology, the First Affiliated Hospital of Fujian Medical University, Fujian Medical University, Fuzhou, 350005, China. [email protected].
7. Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, 350004, China. [email protected].
8. Department of Neurology, Fujian Institute of Neurology, the First Affiliated Hospital of Fujian Medical University, Fujian Medical University, Fuzhou, 350005, China. [email protected].
9. Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, 350004, China. [email protected].
10. Hotchkiss Brain Institute, Department of Clinical Neurosciences, University of Calgary, Calgary, AB, Canada. [email protected].
11. Department of Neurology, Fujian Institute of Neurology, the First Affiliated Hospital of Fujian Medical University, Fujian Medical University, Fuzhou, 350005, China. [email protected].
12. Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, 350004, China. [email protected].
# Contributed equally.

Abstract

Neuroinflammation is a core pathological process in multiple central nervous system diseases. Although positron emission tomography (PET) targeting the translocator protein (TSPO) (e.g., ¹⁸F-DPA-714) is widely used for in vivo inflammatory imaging, the cellular heterogeneity and functional states underlying its imaging signals remain unclear, severely limiting its mechanistic research and clinical translational value. This study used the multifunctional fluorescent TSPO probe (Cy5-PEG3-DPA714) to establish a multidimensional decoding framework that enables systematic analysis of the TSPO signal in neuroinflammation across in vivo, tissue, and single-cell levels. Multiple animal models demonstrated the probe’s ability to dynamically monitor acute and chronic neuroinflammation noninvasively in vivo. Histopathology confirmed that the TSPO signal mainly comes from activated Iba1⁺ microglia. Using the probe’s fluorescence properties, we effectively isolated specific microglial subpopulations with distinct TSPO signaling profiles via flow cytometry. Single-cell analysis revealed that the TSPO signal is specifically enriched in a microglia subpopulation with TSPO probe^high. Importantly, this subpopulation shares features with disease-associated microglia (DAM), exhibiting a robust pro-inflammatory phenotype and significant metabolic reprogramming. Furthermore, we found that TSPO probe^high microglia are highly dependent on the Colony Stimulating Factor 1 Receptor (CSF1R) signal pathway, and selective elimination using the CSF1R inhibitor (PLX3397) reduces neuroinflammation. This study systematically decodes the TSPO signal in neuroinflammation through a multimodal approach, providing novel insights and tools for precision therapeutic strategies targeting specific pathological microglia subpopulations.

Supplementary Information: The online version contains supplementary material available at 10.1186/s12974-026-03829-9.

Keywords

CSF1R; Microglia; Neuroinflammation; TSPO imaging probe; Translocator protein (TSPO).