A Histone Deacetylase 3-Dependent Pathway Delimits Peripheral Myelin Growth and Functional Regeneration [RNA-seq]. Mus musculus

Schwann cell remyelination defects impair functional restoration after nerve damage, contributing to peripheral neuropathies. The mechanisms that mediate remyelination block remain elusive. Upon small-molecule epigenetic screening, we identified HDAC3, a histone-modifying enzyme, as a potent inhibitor of peripheral myelinogenesis. Inhibition of HDAC3 markedly enhances myelin growth and regeneration, and improves functional recovery after peripheral nerve injury. HDAC3 antagonizes myelinogenic neuregulin/PI3K/AKT signaling axis. Moreover, genome-wide profiling analyses reveal that HDAC3 represses pro-myelinating programs through epigenetic silencing, while coordinating with p300 histone acetyltransferase to activate myelination-inhibitory programs that include HIPPO signaling effector TEAD4 to inhibit myelin growth. Schwann-cell-specific deletion of either Hdac3 or Tead4 results in a profound increase in myelin thickness in sciatic nerves. Thus, our findings identify the HDAC3-TEAD4 network as a dual-function switch of cell-intrinsic inhibitory machinery that counters myelinogenic signals and maintains peripheral myelin homeostasis, highlighting the therapeutic potential of transient HDAC3 inhibition for improving peripheral myelin repair. Overall design: 4 RNA-Seq samples from P6 sciatic nerves of Ctrl and Hdac3-cKO mice (Cnpcre-Ctrl, Cnpcre-cKO, Dhhcre-Ctrl, Dhhcre-cKO)