Explore the vast range of titles available.

Macrophage polarization to proinflammatory M1-like or anti-inflammatory M2-like cells is critical to mount a host defense or repair tissue. The exact molecular mechanisms controlling this process are still elusive. Here, we report that ubiquitin-specific protease 19 (USP19) acts as an anti-inflammatory switch that inhibits inflammatory responses and promotes M2-like macrophage polarization. USP19 inhibited NLRP3 inflammasome activation by increasing autophagy flux and decreasing the generation of mitochondrial reactive oxygen species. In addition, USP19 inhibited the proteasomal degradation of inflammasome-independent NLRP3 by cleaving its polyubiquitin chains. USP19-stabilized NLRP3 promoted M2-like macrophage polarization by direct association with interferon regulatory factor 4, thereby preventing its p62-mediated selective autophagic degradation. Consistent with these observations, compared to wild-type mice, Usp19−/− mice had decreased M2-like macrophage polarization and increased interleukin-1β secretion, in response to alum and chitin injections. Thus, we have uncovered an unexpected mechanism by which USP19 switches the proinflammatory function of NLRP3 into an anti-inflammatory function, and suggest that USP19 is a potential therapeutic target for inflammatory interventions.

The precise control of growth and maintenance of the retinal ganglion cell (RGC) dendrite arborization is critical for normal visual functions in mammals. However, the underlying mechanisms remain elusive. Here, we find that the N 6 -methyladenosine (m 6 A) reader YTHDF2 is highly expressed in the mouse RGCs. Conditional knockout (cKO) of Ythdf2 in the retina leads to increased RGC dendrite branching, resulting in more synapses in the inner plexiform layer. Interestingly, the Ythdf2 cKO mice show improved visual acuity compared with control mice. We further demonstrate that Ythdf2 cKO in the retina protects RGCs from dendrite degeneration caused by the experimental acute glaucoma model. We identify the m 6 A-modified YTHDF2 target transcripts which mediate these effects. This study reveals mechanisms by which YTHDF2 restricts RGC dendrite development and maintenance. YTHDF2 and its target mRNAs might be valuable in developing new treatment approaches for glaucomatous eyes.

The reversible epitranscriptomic mark, 5-methylcytosine (m 5 C) modification, is implicated in numerous cellular processes, but its role in neural development remains largely unexplored. In this study, we discovered high expression of the m 5 C reader Ybx1 in the developing mouse cortex. To elucidate its role in cortical development, Ybx1 was ablated in embryonic cortical neural stem cells (NSCs). Interestingly, conditional knockout (cKO) of Ybx1 led to perinatal mortality in mice, along with abnormal cortical development. Cortical progenitor cells lacking Ybx1 exhibited impaired proliferation and differentiation. Multi-omics analysis identified the target mRNAs of Ybx1, which encode the key cell cycle regulatory proteins converging on cyclin D2 (Ccnd2). Ybx1 was found to regulate the stability of its target transcripts. Both knockdown and overexpression of Ybx1 targets via in utero electroporation confirmed that they mediated Ybx1 regulation of proliferation and differentiation of neural precursor cells. Further analysis showed that the G1 to S phase transition in cortical progenitor cells is delayed in the Ybx1 cKO. This study highlights the crucial function of the m 5 C reader protein Ybx1 in promoting cell cycle progression of the embryonic cortical progenitors, essential for proper cortical development.

The accurate construction of neural circuits requires the precise control of axon growth and guidance, which is regulated by multiple growth and guidance cues during early nervous system development. It is generally thought that the growth and guidance cues that control the major steps of axon development have been defined. Here, we describe cerebellin-1 (Cbln1) as a novel cue that controls diverse aspects of axon growth and guidance throughout the central nervous system (CNS) by experiments using mouse and chick embryos. Cbln1 has previously been shown to function in late neural development to influence synapse organization. Here, we find that Cbln1 has an essential role in early neural development. Cbln1 is expressed on the axons and growth cones of developing commissural neurons and functions in an autocrine manner to promote axon growth. Cbln1 is also expressed in intermediate target tissues and functions as an attractive guidance cue. We find that these functions of Cbln1 are mediated by neurexin-2 (Nrxn2), which functions as the Cbln1 receptor for axon growth and guidance. In addition to the developing spinal cord, we further show that Cbln1 functions in diverse parts of the CNS with major roles in cerebellar parallel fiber growth and retinal ganglion cell axon guidance. Despite the prevailing role of Cbln1 as a synaptic organizer, our study discovers a new and unexpected function for Cbln1 as a general axon growth and guidance cue throughout the nervous system.

Messenger RNA m6A modification is shown to regulate local translation in axons. However, how the m6A codes in axonal mRNAs are read and decoded by the m6A reader proteins is still unknown. Here, it is found that the m6A readers YTHDF1 and YTHDF2 are both expressed in cerebellar granule cells (GCs) and their axons. Knockdown (KD) of YTHDF1 or YTHDF2 significantly increases GC axon growth rates in vitro. By integrating anti‐YTHDF1&2 RIP‐Seq with the quantitative proteomic analysis or RNA‐seq after KD of YTHDF1 or YTHDF2, a group of transcripts which may mediate the regulation of GC axon growth by YTHDFs is identified. Among them, Dvl1 and Wnt5a, encoding the key components of Wnt pathway, are further found to be locally translated in axons, which are controlled by YTHDF1 and YTHDF2, respectively. Specific ablation of Ythdf1 or Ythdf2 in GCs increases parallel fiber growth, promotes synapse formation in cerebellum in vivo, and improves motor coordination ability. Together, this study identifies a mechanism by which the m6A readers YTHDF1 and YTHDF2 work synergistically on the Wnt5a pathway through regulating local translation in GC axons to control cerebellar parallel fiber development. The m6A readers, YTHDF1 and YTHDF2, negatively regulate axon growth of cerebellar granule cells (GCs) by mediating local translation of Dvl1 and Wnt5a in axons, respectively. Conditional knockout (cKO) of Ythdf1 or Ythdf2 in cerebellar GCs enhances parallel fiber growth and GC‐PC (Purkinje cells) synapse formation, which eventually improves the motor coordination ability of cKO mice.

N 6 -methyladenosine (m 6 A) modification, as the most prevalent internal modification on mRNA, has been implicated in many biological processes through regulating mRNA metabolism. Given that m 6 A modification is highly enriched in the mammalian brain, this dynamic modification provides a crucial new layer of epitranscriptomic regulation of the nervous system. Here, in this review, we summarize the recent progress on studies of m 6 A modification in the mammalian nervous system ranging from neuronal development to basic and advanced brain functions. We also highlight the detailed underlying mechanisms in each process mediated by m 6 A writers, erasers, and readers. Besides, the involvement of dysregulated m 6 A modification in neurological disorders and injuries is discussed as well.

Autophagy is a fundamental cellular process of protein degradation and recycling that regulates immune signaling pathways via multiple mechanisms. However, it remains unclear how autophagy epigenetically regulates the immune response. Here, we identified TRIM14 as an epigenetic regulator that reduces histone H3K9 trimethylation by inhibiting the autophagic degradation of the histone demethylase KDM4D. TRIM14 recruited the deubiquitinases USP14 and BRCC3 to cleave the K63-linked ubiquitin chains of KDM4D, which prevented KDM4D from undergoing optineurin (OPTN)-mediated selective autophagy. Tripartite motif-containing 14 (TRIM14) deficiency in dendritic cells significantly impaired the expression of the KDM4D-directed proinflammatory cytokines interleukin 12 (Il12) and Il23 and protected mice from autoimmune inflammation. Taken together, these findings highlight the cross-talk between epigenetic regulation and autophagy and suggest TRIM14 is a potential target of therapeutic intervention for inflammation-related diseases.

The reversible epitranscriptomic mark, 5-methylcytosine (m.sup.5 C) modification, is implicated in numerous cellular processes, but its role in neural development remains largely unexplored. In this study, we discovered high expression of the m.sup.5 C reader Ybx1 in the developing mouse cortex. To elucidate its role in cortical development, Ybx1 was ablated in embryonic cortical neural stem cells (NSCs). Interestingly, conditional knockout (cKO) of Ybx1 led to perinatal mortality in mice, along with abnormal cortical development. Cortical progenitor cells lacking Ybx1 exhibited impaired proliferation and differentiation. Multi-omics analysis identified the target mRNAs of Ybx1, which encode the key cell cycle regulatory proteins converging on cyclin D2 (Ccnd2). Ybx1 was found to regulate the stability of its target transcripts. Both knockdown and overexpression of Ybx1 targets via in utero electroporation confirmed that they mediated Ybx1 regulation of proliferation and differentiation of neural precursor cells. Further analysis showed that the G1 to S phase transition in cortical progenitor cells is delayed in the Ybx1 cKO. This study highlights the crucial function of the m.sup.5 C reader protein Ybx1 in promoting cell cycle progression of the embryonic cortical progenitors, essential for proper cortical development.