Cell Research最新文献

Advances in transcriptomic technologies have progressively transformed the questions we can ask and answer about muscle stem cells (MuSCs) during aging. Early microarray and bulk RNA sequencing studies established foundational population-level signatures of aged MuSCs, including attenuation of myogenic and metabolic programs as well as induction of inflammatory and stress-associated transcription. However, these averaged readouts obscured cell-to-cell variability and rare functional states. The transition to single-cell and single-nucleus RNA sequencing marked a turning point by resolving MuSC heterogeneity and revealing that MuSC aging is not purely stochastic. Instead, aged MuSC pools show reproducible changes in state composition, delayed or altered myogenic lineage progression, and selective vulnerability of specific functional subsets. Emerging spatial transcriptomic approaches, although still limited by sensitivity and cell-type discrimination in muscle, are beginning to place these MuSC states into their native tissue context, directly linking transcriptional states, niche organization, and age-associated remodeling. In parallel, integrative multi-omic designs that pair transcriptomics with chromatin accessibility and metabolic measurements have strengthened mechanistic connections among age-associated gene programs, epigenetic remodeling, and metabolic state shifts. Finally, computational frameworks - including trajectory inference, dynamic modeling, and machine learning - are increasingly applied to high-dimensional transcriptomic data to predict aging trajectories and identify candidate rejuvenation targets. In this Perspective, we trace the evolution of transcriptomic technologies through the lens of MuSC aging and highlight how increasing resolution has reframed core models of MuSC decline and plasticity.

AMPA receptors (AMPARs) mediate the majority of fast excitatory synaptic transmission throughout the central nervous system. Calcium-permeable AMPARs and GluA4-containing receptors are critical for cerebellar functions, such as motor learning, associative memory, auditory processing, and synaptic plasticity. In contrast to the well-characterized, predominantly GluA2-containing AMPARs of the hippocampus and cortex, cerebellar AMPARs contain a higher proportion of GluA4 and remain poorly understood. Here, we generated a highly GluA4-specific antibody. Using this antibody in combination with antibodies specifically recognizing GluA1 and GluA2, we purified native AMPARs and determined the subunit compositions of both calcium-impermeable and calcium-permeable native AMPARs in the cerebellum. The isolated cerebellar AMPARs that contained both GluA1 and GluA4 were calcium-permeable, with GluA4 occupying mainly the B/D positions, GluA1 occupying the A/C positions, and the complex associated primarily with cornichon 3 (CNIH3). We determined the structures of the complex in distinct functional states, including the resting, active, and desensitized states, and characterized the conformational transitions that underlie its activity. During desensitization, the receptor adopts a pseudo-4-fold configuration of the ligand-binding domain layer, which may be important for its functional properties. This study provides a blueprint for the subunit compositions of AMPARs in the cerebellum and clarifies the gating mechanism of the calcium-permeable native AMPAR^A1A4-CNIH3 complex, providing significant insight into AMPAR-mediated synaptic transmission in the cerebellum.