NAT10 promotes synovial aggression by increasing the stability and translation of N4-acetylated PTX3 mRNA in rheumatoid arthritis

NAT10 exacerbates acute renal inflammation by enhancing N4-acetylcytidine modification of the CCL2/CXCL1 axis

Inflammation plays an essential role in eliminating microbial pathogens and repairing tissues, while sustained inflammation accelerates kidney damage and disease progression. Therefore, understanding the mechanisms of the inflammatory response is vital for developing therapies for inflammatory kidney diseases like acute kidney injury (AKI), which currently lacks effective treatment. Here, we identified N-acetyltransferase 10 (NAT10) as an important regulator for acute inflammation. NAT10, the only known "writer" protein for N4-acetylcytidine (ac4C) acetylation, is elevated in renal tubules across various AKI models, human biopsies, and cultured tubular epithelial cells (TECs). Conditional knockout (cKO) of NAT10 in mouse kidneys attenuates renal dysfunction, inflammation, and infiltration of macrophages and neutrophils, whereas its conditional knock-in (cKI) exacerbates these effects. Mechanistically, our findings from ac4C-RIP-seq and RNA-seq analyses revealed that NAT10-mediated ac4C acetylation enhances the mRNA stability of a range of key chemokines, including C-C motif chemokine ligand 2 (CCL2) and C-X-C motif chemokine ligand 1(CXCL1), promoting macrophage and neutrophil recruitment and accelerating renal inflammation. Additionally, CCL2 and CXCL1 neutralizing antibodies or their receptor inhibitors, abrogated renal inflammation in NAT10-overexpression TECs or NAT10-cKI mice. Importantly, inhibiting NAT10, either through Adeno-associated virus 9 (AAV9)-mediated silencing or pharmacologically with our found inhibitor Cpd-155, significantly reduces renal inflammation and injury. Thus, targeting the NAT10/CCL2/CXCL1 axis presents a promising therapeutic strategy for treating inflammatory kidney diseases.

Acetyltransferase NAT10 promotes an immunosuppressive microenvironment by modulating CD8+ T cell activity in prostate cancer

N-acetyltransferase 10 (NAT10), an enzyme responsible for ac4C acetylation, is implicated in cancer progression, though its specific biological function in prostate cancer remains insufficiently understood. This study clarifies NAT10's role in prostate cancer and its effects on the tumor immune microenvironment. NAT10 expression and clinical relevance were assessed through bioinformatics, RT-qPCR, and IHC analyses, comparing prostate cancer tissues with normal controls. The impact of NAT10 on tumor cell proliferation, migration, and invasion was investigated via in vitro assays-including CCK-8, EdU, wound healing, and 3D-Transwell-as well as in vivo mouse xenograft models and organoid studies. Further, NAT10's influence on immune cell infiltration was examined using flow cytometry, IHC, cell co-culture assays, and ELISA to elucidate downstream chemokine effects, specifically targeting CD8+ T cells. Findings indicated significant upregulation of NAT10 in prostate cancer cells, enhancing their proliferative and invasive capacities. Notably, NAT10 suppresses CD8+ T cell recruitment and cytotoxicity through the CCL25/CCR9 axis, fostering an immunosuppressive microenvironment that exacerbates tumor progression. An ac4C modification score was also devised based on NAT10's downstream targets, providing a novel predictive tool for evaluating immune infiltration and forecasting immunotherapy responses in patients with prostate cancer. This study underscores NAT10's pivotal role in modulating the prostate cancer immune microenvironment, offering insights into the immune desert phenomenon and identifying NAT10 as a promising therapeutic target for improving immunotherapy efficacy.

Single-Cell Multi-Dimensional data analysis reveals the role of ARL4C in driving rheumatoid arthritis progression and Macrophage polarization dynamics

Rheumatoid arthritis (RA) is an enduring autoimmune inflammatory condition distinguished by continual joint inflammation, hyperplasia of the synovium, erosion of bone, and deterioration of cartilage.Fibroblast-like synoviocytes (FLSs) exhibiting "tumor-like" traits are central to this mechanism.ADP-ribosylation factor-like 4c (ARL4C) functions as a Ras-like small GTP-binding protein, significantly impacting tumor migration, invasion, and proliferation.However, it remains uncertain if ARL4C participates in the stimulation of RA FLSs exhibiting "tumor-like" features, thereby fostering the advancement of RA. In our investigation, we unveiled, for the inaugural instance, via the amalgamated scrutiny of single-cell RNA sequencing (scRNA-seq) and Bulk RNA sequencing (Bulk-seq) datasets, that activated fibroblast-like synoviocytes (FLSs) showcase high expression of ARL4C, and the ARL4C protein expression in FLSs derived from RA patients significantly surpasses that observed in individuals with osteoarthritis (OA) and traumatic injury (trauma).Silencing of the ARL4C gene markedly impeded the proliferation of RA FLSs by hindered the transition of cells from the G0/G1 phase to the S phase, and intensified cell apoptosis and diminished the migratory and invasive capabilities. Co-culture of ARL4C gene-silenced RA FLSs with monocytes/macrophages significantly inhibited the polarization of monocytes/macrophages toward M1 and the repolarization of M2 to M1.Furthermore, intra-articular injection of shARL4C significantly alleviated synovial inflammation and cartilage erosion in collagen-induced arthritis (CIA) rats. In conclusion, our discoveries propose that ARL4C assumes a central role in the synovial inflammation, cartilage degradation, and bone erosion associated with RA by triggering the PI3K/AKT and MAPK signaling pathways within RA FLSs.ARL4C holds promise as a prospective target for the development of pharmaceutical agents targeting FLSs, with the aim of addressing RA.