Protein & Cell最新文献

Genome-wide off-target effect poses a safety risk for clinical use of adenine base editor (ABEs), among which ABE8e is one of the most efficient. Two-cell embryo injection (GOTI) analysis showed that the rate of genome-wide single nucleotide variants (SNVs) in ABE8e-edited cells was ∼30-fold higher than that of spontaneous SNVs in control cells, indicating prevalent off-target effects of ABE8e, but no off-target effect for ABE7.10, from which ABE8e was derived. We performed saturation mutagenesis of eight amino acid sites of the deaminase (TadA8e) within ABE8e and obtained ABE8eY149V that exhibited high editing efficiency without detectable off-target effect. Furthermore, TadA8eY149V could be fused with other Cas homologs (PAM-relaxed SpRY, hypercompact SaKKH, or IscB) to expand its target range. Finally, ABE8eY149V editing of hydroxyphenylpyruvate dioxygenase (Hpd) gene prevented lethality in hereditary tyrosinemia type I mice. The high efficiency and fidelity of ABE8eY149V suggest its potential application in ABE-based gene therapies.

Esophageal squamous cell carcinoma (ESCC) remains a major health burden, particularly in Asia, with poor patient prognosis despite advancements in radiotherapy, chemotherapy, and immunotherapy. The marked inter-patient and intra-tumor heterogeneity of ESCC underscores the need for molecularly informed diagnostic and therapeutic strategies. Recent high-throughput omics technologies, including genomics, transcriptomics, proteomics, and metabolomics, have substantially advanced our understanding of ESCC biology. Genomic profiling has revealed recurrent alterations such as TP53 and NOTCH1 mutations, as well as actionable targets including PIK3CA, FGFR1, and SOX2 amplifications, which provide new opportunities for precision therapy. Epigenomic and transcriptomic analyses have identified methylation-based early detection markers (e.g., PAX9, SIM2) and immune-related transcriptomic subtypes associated with prognosis and immunotherapy responsiveness. Proteomic and metabolomic studies have further uncovered cell cycle and spliceosome pathway activation and altered lactate metabolism, offering additional biomarker and therapeutic insights. In this review, we synthesize these multi-omics advances and highlight how they collectively inform improved diagnostic, prognostic, and therapeutic strategies for ESCC. Despite these developments, the clinical translation of multi-omics findings remains limited due to the lack of standardized analytical pipelines, insufficient multi-center validation, and the high cost and technical complexity of integrating multi-omics data into routine clinical workflows. Future research integrating artificial intelligence with multi-omics data holds promise for enhancing diagnostic accuracy and enabling more precise therapeutic decision-making in ESCC.

The endocrine system is crucial for maintaining overall homeostasis. However, its cellular signatures have not been elucidated during aging. Here, we conducted the first-ever single-cell transcriptomic profiles from eight endocrine organs in young and aged mice, revealing the activation of cell-type-specific aging pathways, such as loss of proteostasis, genomic instability and reactive oxygen species (ROS). Among six sex-shared endocrine organs, aging severely impaired gene expression networks in functional endocrine cells, accompanied by enhanced immune infiltration and unfolded protein response (UPR). Mechanism investigations showed that expanded aging-associated exhausted T cells activated MHC-I-UPR axis across functional endocrine cells by releasing GZMK. The inhibition of GZMK receptors by small chemical molecules counteracted the UPR and senescence, suggesting the immune infiltration is a possible driver of endocrine aging. Machine learning identified CD59 as a novel aging feature in sex-shared functional endocrine cells. For two sex-specific endocrine organs, both aged ovaries and testes showed enhanced immune responses. Meanwhile, cell-type-specific aging-associated transcriptional changes revealed an enhanced ROS mainly in aged theca cells of ovaries, while aged spermatogonia in testes showed impaired DNA repair. This study provides a comprehensive analysis of endocrine system aging at single-cell resolution, offering profound insights into mechanisms of endocrine aging.

Respiratory syncytial virus (RSV) exploits host proteases to enhance its replication efficiency; however, the precise mechanisms remain unclear. Through high-throughput screening, we identified four matrix metalloproteinase 9 (MMP-9) inhibitors (including JNJ0966 and doxycycline hyclate) that suppress RSV infection in vitro and in vivo. Mechanistic studies revealed a proteolytic cascade wherein MMP-9 cleaves transglutaminase 2 (TGM2) at the PVP375↓VR site, generating an N-terminal fragment (1-375) that activates its protein disulfide isomerase (PDI) activity. This TGM2-dependent PDI activity catalyzes disulfide bond rearrangement in the RSV fusion glycoprotein (F), enabling F protein maturation, a prerequisite for membrane fusion and syncytium formation-key processes driving late-stage viral propagation. Genetic ablation of MMP-9 significantly attenuated RSV infectivity, while pharmacological inhibition reduced pulmonary viral loads and mitigated lung pathology in infected mice. Our study defines a unified MMP-9→TGM2→F axis as the core mechanism driving RSV replication and validates MMP-9 as a therapeutic target.