21:T54a,Dysregulation of extracellular matrix (ECM) homeostasis plays a pivotal role in the accelerated degradation of cartilage, presenting a notable challenge for effective osteoarthritis (OA) treatment and cartilage regeneration. In this study, we introduced an injectable hydrogel based on streamlined-zinc oxide (ZnO), which is responsive to matrix metallopeptidase (MMP), for the delivery of miR-17-5p. This approach aimed to address cartilage damage by regulating ECM homeostasis. The ZnO/miR-17-5p composite functions by releasing zinc ions to attract native bone marrow mesenchymal stem cells, thereby fostering ECM synthesis through the proliferation of new chondrocytes. Concurrently, sustained delivery of miR-17-5p targets enzymes responsible for matrix degradation, thereby mitigating the catabolic process. Notably, the unique structure of the streamlined ZnO nanoparticles is distinct from their conventional spherical counterparts, which not only optimizes the rheological and mechanical properties of the hydrogels, but also enhances the efficiency of miR-17-5p transfection. Our male rat model demonstrated that the combination of streamlined ZnO, MMP-responsive hydrogels, and miRNA-based therapy effectively managed the equilibrium between catabolism and anabolism within the ECM, presenting a fresh perspective in the realm of OA treatment.22:T4df,N⁶-methyladenosine (m⁶A) methylation of RNA by the methyltransferase complex (MTC), with core components including METTL3-METTL14 heterodimers and Wilms' tumor 1-associated protein (WTAP), contributes to breast tumorigenesis, but the underlying regulatory mechanisms remain elusive. Here, we identify a novel cleaved form METTL3a (residues 239-580 of METTL3). We find that METTL3a is required for the METTL3-WTAP interaction, RNA m⁶A deposition, as well as cancer cell proliferation. Mechanistically, we find that METTL3a is essential for the METTL3-METTL3 interaction, which is a prerequisite step for recruitment of WTAP in MTC. Analysis of m⁶A sequencing data shows that depletion of METTL3a globally disrupts m⁶A deposition, and METTL3a mediates mammalian target of rapamycin (mTOR) activation via m⁶A-mediated suppression of TMEM127 expression. Moreover, we find that METTL3 cleavage is mediated by proteasome in an mTOR-dependent manner, revealing positive regulatory feedback between METTL3a and mTOR signaling. Our findings reveal METTL3a as an important component of MTC, and suggest the METTL3a-mTOR axis as a potential therapeutic target for breast cancer.23:T6a0,

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