Expression of huntingtin-associated protein 1 in adult mouse dorsal root ganglia and its neurochemical characterization in reference to sensory neuron subpopulations
Md Nabiul Islam,
Naoki Maeda,
Emi Miyasato,
Mir Rubayet Jahan,
Abu Md Mamun Tarif,
Taiga Ishino,
Kanako Nozaki,
Koh-hei Masumoto,
Akie Yanai,
Koh Shinoda
Affiliations
Md Nabiul Islam
Division of Neuroanatomy, Department of Neuroscience, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, 755-8505, Japan
Naoki Maeda
Division of Neuroanatomy, Department of Neuroscience, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, 755-8505, Japan
Emi Miyasato
Division of Neuroanatomy, Department of Neuroscience, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, 755-8505, Japan
Mir Rubayet Jahan
Division of Neuroanatomy, Department of Neuroscience, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, 755-8505, Japan; Department of Anatomy and Histology, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh, 2202, Bangladesh
Abu Md Mamun Tarif
Division of Neuroanatomy, Department of Neuroscience, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, 755-8505, Japan
Taiga Ishino
Division of Neuroanatomy, Department of Neuroscience, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, 755-8505, Japan
Kanako Nozaki
Division of Neuroanatomy, Department of Neuroscience, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, 755-8505, Japan
Koh-hei Masumoto
Division of Neuroanatomy, Department of Neuroscience, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, 755-8505, Japan
Akie Yanai
Division of Neuroanatomy, Department of Neuroscience, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, 755-8505, Japan; Department of Basic Laboratory Sciences, Faculty of Medicine and Health Sciences, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, 755-8505, Japan
Koh Shinoda
Division of Neuroanatomy, Department of Neuroscience, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, 755-8505, Japan; Corresponding author at: Division of Neuroanatomy, Department of Neuroscience, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, 755-8505, Japan.
Huntingtin-associated protein 1 (HAP1) is a polyglutamine (polyQ) length-dependent interactor with causal agents in several neurodegenerative diseases and has been regarded as a protective factor against neurodegeneration. In normal rodent brain and spinal cord, HAP1 is abundantly expressed in the areas that are spared from neurodegeneration while those areas with little HAP1 are frequent targets of neurodegeneration. We have recently showed that HAP1 is highly expressed in the spinal dorsal horn and may participate in modification/protection of certain sensory functions. Neurons in the dorsal root ganglia (DRG) transmits sensory stimuli from periphery to spinal cord/brain stem. Nevertheless, to date HAP1 expression in DRG remains unreported. In this study, the expression of HAP1 in cervical, thoracic, lumbar and sacral DRG in adult male mice and its relationships with different chemical markers for sensory neurons were examined using Western blot and immunohistochemistry. HAP1-immunoreactivity was detected in the cytoplasm of DRG neurons, and the percentage of HAP1-immunoreactive (ir) DRG neurons was ranged between 28–31 %. HAP1-immunoreactivity was comparatively more in the small cells (47–58 %) and medium cells (40–44 %) than that in the large cells (9–11 %). Double-immunostaining for HAP1 and markers for nociceptive or mechanoreceptive neurons showed that about 70–80 % of CGRP-, SP-, CB-, NOS-, TRPV1-, CR- and PV-ir neurons expressed HAP1. In contrast, HAP1 was completely lacking in TH-ir neurons. Our current study is the first to clarify that HAP1 is highly expressed in nociceptive/proprioceptive neurons but absent in light-touch-sensitive TH neurons, suggesting the potential importance of HAP1 in pain transduction and proprioception.
