Methylation of histone by protein arginine methyltransferases (PRMTs) plays an important role in gene regulation. PRMT1- and PRMT4-catalyzed methyl-arginine is involved in transcription activation, while PRMT5- and PRMT6-catalyzed methyl-arginine is associated with transcription repression. Histone arginine methylation can be dynamically regulated in vivo, and methyl-arginine is demethylated by "arginine demethylase". Here, the most recent progresses in the methylation studies of histone arginine were summarized.

Degenerative disc disease (DDD) is a leading cause of low back pain, which severely affects the quality of life and incurs significant medical cost. Annulus fibrosus(AF) injuries can lead to substantial deterioration of intervertebral disc degeneration. However, the AF repair/regeneration remains a challenge due to the intrinsic cellular, biochemical and biomechanical heterogeneity of AF tissue. Tissue engineering would be a promising approach for AF regeneration. This article aims to provide a brief overview of the fundamental aspects of AF, the current achievements and future challenges of AF tissue engineering. A multidisciplinary approach is proposed for future studies to fully mimic the native AF tissue and its microenvironment, including choosing adequate cell source, preparing scaffolds with hierarchical microstructures, supplementing appropriate growth factors, and enforcing suitable mechanical stimulation. Hopefully, the engineered AF tissues would be effectively used to facilitate the treatment of DDD in the future.
Humans ; Intervertebral Disc ; growth & development ; Intervertebral Disc Degeneration ; therapy ; Regeneration ; Tissue Engineering