NADH-DLEM-seq: A High-Fidelity Multimodal Platform Revealing Fiber-Type-Specific Metabolic and Transcriptional Remodeling in Sarcopenia

Unraveling the spatial heterogeneity of tissue microenvironments is essential for understanding complex pathologies like sarcopenia. However, existing spatial omics technologies often compromise between single-cell resolution, macromolecular integrity, and metabolic context. Here, we present "Donut" Laser Ejection Microdissection (DLEM), a high-throughput, non-contact spatial sampling platform. By integrating Spatial Light Modulator (SLM)-based vortex beam shaping with a metal-assisted ejection mechanism, DLEM achieves subcellular precision (5µm) and "cold-cutting" isolation, fundamentally eliminating thermal damage. This ensures superior RNA quality, maintaining > 82.5% genome alignment rates even at the single-cell level. We developed a multimodal NADH-DLEM-seq workflow to link in situ metabolic phenotypes with transcriptomic profiles. Applying this to a murine model of chronic kidney disease (CKD)-induced sarcopenia, we dissected the distinct molecular trajectories of oxidative (Type I) and glycolytic (Type IIB) myofibers. We reveal a dichotomous response to stress: Type I fibers undergo profibrotic remodeling via collagen signaling activation, whereas Type IIB fibers exhibit pronounced catabolic atrophy and mitochondrial disassembly. These findings, obscured in bulk analyses, underscore DLEM as a powerful tool for deciphering the metabolic-transcriptional coupling in aging and disease, offering precise targets for therapeutic intervention in sarcopenia.