2. Academic Validation
  3. Neuronal cathepsin S increases neuroinflammation and causes cognitive decline via CX3CL1-CX3CR1 axis and JAK2-STAT3 pathway in aging and Alzheimer's disease

Neuronal cathepsin S increases neuroinflammation and causes cognitive decline via CX3CL1-CX3CR1 axis and JAK2-STAT3 pathway in aging and Alzheimer's disease

  • Aging Cell. 2024 Oct 25:e14393. doi: 10.1111/acel.14393.
Pei-Pei Liu 1 2,  Xiao-Hui Liu 1 2,  Ming-Jing Ren 3,  Xiao-Tong Liu 4,  Xiao-Qing Shi 5,  Ming-Li Li 2,  Shu-Ang Li 1 2,  Yang Yang 1 2,  Dian-Dian Wang 1 2,  Yue Wu 1 2,  Fan-Xiang Yin 6,  Yan-Hong Guo 3,  Run-Zhou Yang 1,  Meng Cheng 7,  Yong-Juan Xin 8,  Jian-Sheng Kang 1 2,  Bing Huang 9,  Kai-Di Ren 10
Affiliations

Affiliations

  • 1 Clinical Systems Biology Laboratories, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.
  • 2 Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.
  • 3 Department of Nephropathy, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.
  • 4 Department of Clinical Laboratory, The First Hospital of Yongnian District, Hebei, China.
  • 5 Department of Clinical Laboratory, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.
  • 6 Translational Medical Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
  • 7 Henan Branch, Bank of China, Zhengzhou, Henan, China.
  • 8 Department of Child and Adolescent Health, Precision Nutrition Innovation Center, School of Public Health, Zhengzhou University, Zhengzhou, Henan, China.
  • 9 Pain and Related Disease Research Laboratory, Shantou University Medical College, Shantou, Guangdong, China.
  • 10 Department of Pharmacy, The First Affiliated Hospital of Zhengzhou University4, Zhengzhou, Henan, China.
PMID: 39453382 DOI: 10.1111/acel.14393
Abstract

Aging is an intricate process involving interactions among multiple factors, which is one of the main risks for chronic diseases, including Alzheimer's disease (AD). As a member of cysteine protease, Cathepsin S (CTSS) has been implicated in inflammation across various diseases. Here, we investigated the role of neuronal CTSS in aging and AD started by examining CTSS expression in hippocampus neurons of aging mice and identified a significant increase, which was negatively correlated with recognition abilities. Concurrently, we observed an elevation of CTSS concentration in the serum of elderly people. Transcriptome and fluorescence-activated cell sorting (FACS) results revealed that CTSS overexpression in neurons aggravated brain inflammatory milieu with microglia activation to M1 pro-inflammatory phenotype, activation of chemokine C-X3-C-motif ligand 1 (CX3CL1)-chemokine C-X3-C-motif receptor 1 (CX3CR1) axis and janus kinase 2 (JAK2)-signal transducer and activator of transcription 3 (STAT3) pathway. As CX3CL1 is secreted by neurons and acts on the CX3CR1 in microglia, our results revealed for the first time the role of neuron CTSS in neuron-microglia "crosstalk." Besides, we observed elevated CTSS expression in multiple brain regions of AD patients, including the hippocampus. Utilizing CTSS selective inhibitor, LY3000328, rescued AD-related pathological features in APP/PS1 mice. We further noticed that neuronal CTSS overexpression increased Cathepsin B (CTSB) activity, but decreased Cathepsin L (CTSL) activity in microglia. Overall, we provide evidence that CTSS can be used as an aging biomarker and plays regulatory roles through modulating neuroinflammation and recognition in aging and AD process.

Keywords

Alzheimer's disease; aging; cathepsin S; neurodegenerative disease; neuroinflammation; recognition.

Figures
Products