2. Academic Validation
  3. Spatiotemporal mapping reveals Ccl8hi macrophages as key drivers of testicular inflammaging

Spatiotemporal mapping reveals Ccl8hi macrophages as key drivers of testicular inflammaging

  • Clin Transl Med. 2025 Nov;15(11):e70527. doi: 10.1002/ctm2.70527.
Yanping Huang 1,  Jiahui Yao 2 3,  Zhiqiang Zhang 4,  Bin Ouyang 5,  Jintao Zhuang 3,  Xianshen Sha 6,  Canhui Qu 3,  Chengqiang Mo 3,  Mujun Lu 1,  Nanhe Lin 3,  Xiangzhou Sun 3,  Qiyun Yang 3,  Yun Xie 3
Affiliations

Affiliations

  • 1 Department of Urology and Andrology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Institute of Andrology, Shanghai, China.
  • 2 Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.
  • 3 Department of Urology and Andrology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
  • 4 Department of Andrology, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, China.
  • 5 Center for Reproductive Medicine, Guangdong Women and Children Hospital, Guangzhou, China.
  • 6 Department of Urology, The First Affiliated Hospital of Jinan University, Guangzhou, China.
PMID: 41251087 DOI: 10.1002/ctm2.70527
Abstract

Background: Testicular macrophages (TMs) are key regulators of testicular immune privilege and endocrine function in the testis. However, their age-related heterogeneity and role in testicular degeneration remain poorly characterized.

Methods: We performed spatial transcriptomics and FACS-enriched single-cell RNA Sequencing (scRNA-seq) to characterize testicular macrophage heterogeneity across ageing. Key findings were validated through intratesticular injection of recombinant CCL8 protein, organotypic culture of seminiferous tubules, and immunofluorescence analysis.

Results: Using spatial transcriptomics, we identified pronounced Leydig niche senescence in aged testes, mechanistically linked to TM-mediated inflammatory remodelling. Coupling FACS-enriched TM isolation with scRNA-seq resolved seven transcriptionally distinct subpopulations, including ageing-associated subsets (Ccl8hi and Cxcl13hi). These subsets exhibited inflammatory signalling rewiring (e.g., CCL8-CCR2 axis) and activation of senescence transcriptional regulators (ASCL2, SPI1, CEBPB, JUNB), with conserved mediators (CCL8, TREM2, IL1β, and CXCL2) across murine and human testes. Functional validation showed that intratesticular injection of recombinant CCL8 protein in 3-month-old mice recapitulated ageing phenotypes, such as germ cell Apoptosis and steroidogenic decline.

Conclusions: Our multi-omics atlas highlights TM heterogeneity as a driver of testicular inflammaging and identifies CCL8 as a conserved target for therapeutic interventions aimed at mitigating age-associated male reproductive decline.

Key points: Spatiotemporal multi‑omics establish inflammaging as a defining feature of testicular ageing. A refined CD74‑based sorting strategy improves enrichment of testicular macrophages. scRNA-seq resolves seven TM subsets with age‑dependent shifts. TM‑secreted inflammatory mediators-especially CCL8-drive testicular inflammaging.

Keywords

CCL8; inflammaging; spatiotemporal transcriptomics; testicular macrophages.

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