Issue Cover (September 2019)

Front cover: The expression of interleukin‐33 (IL‐33), a member of the IL1 family, has been found in gray matter astrocytes and white matter oligodendrocyte (OLG) lineages in the central nervous system (CNS). The glia cell‐derived IL‐33 molecules play a regulatory role in synaptic homeostasis and CNS tissue repair. We show here that in the corpus callosum IL‐33 was mainly in CC1 + ‐OLGs and NG2 + ‐ oligodendrocyte precursor cells (OPCs). Nevertheless, the functional role of IL‐33 in the progression of OLG lineage remains largely unknown. Through lentivirus‐mediated shRNA delivery against IL‐33 expression (IL33‐KD) at the stage OPCs, we demonstrated that IL33‐KD reduced the generation of mature OLGs with the expression of myelin proteins. The results were validated by the examination of OLG differentiation from OPCs with IL‐33 gene knockout (IL33‐KO). The impairment of the myelin integrity was observed in the corpus callosum of the IL33‐KO mice with anxiolytic‐like behavior. This study points out to the important role of IL‐33 in OLG lineage progression. The association of IL‐33 dysfunction in OPCs with the development of behavioral abnormality will be further dissected. Image content: Image 1: Microscope image from immunofluorescence to observe the differentiation of oligodendrocytes with the expression of the myelin basic protein (MBP; red), a marker of myelinating OLGs. This image captures mature MBP‐expressing oligodendrocytes with a sheet‐like extension. The cell nuclei were stained using DAPI (blue). Image 2. Transmission electron microscopic image to observe the compact myelin sheaths in the corpus callosum of WT mice. Image 3. Transmission electron microscopic image to observe the disruption of myelin sheaths in the corpus callosum of mice with IL33‐KO.Read the full article ‘Down‐regulation of interleukin‐33 expression in oligodendrocyte precursor cells impairs oligodendrocyte lineage progression’ by H.‐Y. Sung, W.‐Y. Chen, H.‐T. Huang, C.‐Y. Wang, S.‐B. Chang, S.‐F. Tzeng ( J. Neurochem . 2019, vol. 150 (6), pp. 691–708) on doi: 10.1111/jnc.14788