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Distribution of HAP1‐immunoreactive cells in the spinal cord is suggestive of its protective roles against neurodegeneration in vivo
Author(s) -
Islam Nabiul,
Takeshita Yukio,
Jahan Mir Rubayet,
Yanai Akie,
Masumoto Kohhei,
Shinoda Koh
Publication year - 2019
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2019.33.1_supplement.450.7
Subject(s) - neurodegeneration , spinal cord , biology , neuroscience , striatum , atrophy , huntingtin , pathology , anatomy , huntington's disease , medicine , disease , dopamine
Huntingtin‐associated protein 1 (HAP1) is a neuronal interactor with causatively polyglutamine (polyQ)‐expanded huntingtin in Huntington's disease and also associated with pathologically polyQ‐expanded androgen receptor (AR) in spinobulbar muscular atrophy (SBMA), being considered as a protective factor against neurodegenerative apoptosis. In normal rodent brains, it is abundantly expressed particularly in the limbic‐hypothalamic regions that tend to be spared from neurodegeneration, whereas the areas with little HAP1 expression, including the striatum, thalamus, cerebral neocortex and cerebellum, are targets in several neurodegenerative diseases. While the spinal cord is another major neurodegenerative target, HAP1‐immunoreactive (ir) structures have yet to be determined there. In the current study, HAP1 expression was immunohistochemically evaluated in light and electron microscopy through the cervical, thoracic, lumbar, and sacral spinal cords of the adult rats and mice. Our results showed that HAP1 is specifically expressed in neurons through the spinal segments and that more than 90% of neurons expressed HAP1 in lamina I–II, lamina X, and autonomic preganglionic regions. Double‐immunostaining for HAP1 and AR demonstrated that more than 80% of neurons expressed both in laminae I‐II and X. In contrast, HAP1 was specifically lacking in the lamina IX motoneurons with or without AR expression. The present study first demonstrated that HAP1 is abundantly expressed in spinal neurons of the somatosensory, viscerosensory, and autonomic regions but absent in somatomotor neurons, suggesting that the spinal motoneurons are, due to lack of putative HAP1 protectivity, more vulnerable to stresses in neurodegenerative diseases than other HAP1‐expressing neurons probably involved in spinal sensory and autonomic functions. Support or Funding Information This work was supported by Japan Society for the Promotion of Science KAKENHI (Grant Numbers 18K15006 to Md Nabiul Islam and 16H05118 to Koh Shinoda). This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .