Expression of secreted phosphoprotein 1 (osteopontin) in human sensorimotor cortex and spinal cord: Changes in patients with amyotrophic lateral sclerosis.
Secreted phosphoprotein 1 (SPP1, also known as osteopontin) is expressed in large pyramidal neurons in the primary motor cortex (M1) of certain primate species, including macaque monkeys, but not of rodents. Based on this, we suggested that SPP1 expression may reflect the functional or structural specialization of highly developed corticospinal systems. In the present study, we further characterized SPP1 in the human central nervous system by investigating its expression in the primary somatosensory cortex (S1) and spinal cord, in addition to M1. Although a small number of SPP1-positive pyramidal neurons were observed in S1, the number was smaller than that in M1. In the cervical segment of the spinal cord, SPP1 was principally expressed in choline acetyltransferase-positive motor neurons in lamina IX. We also examined SPP1 expression in patients with amyotrophic lateral sclerosis (ALS), a disease characterized by the degeneration of motor neurons. When SPP1 expression was compared in neurons of the same size range, expression in both M1 and the spinal cord of ALS patients was lower than that of subjects without ALS. SPP1 expression was especially reduced in surviving large neurons in both M1 and the spinal cord of ALS patients. The results further support the concept that SPP1 has a role in the specialization of motor projection neurons and suggest that its reduced expression may be implicated in the neurodegeneration seen in ALS.
Human Informatics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Umezono, Tsukuba, Ibaraki 305-8568, Japan; Department of Physical Therapy, Faculty of Medical and Health Sciences, Tsukuba International University, Tsuchiura, Ibaraki 300-0051, Japan.
Tatsuya
T
Yamamoto
Department of Neuropathology (Brain Bank for Aging Research), Tokyo Metropolitan Geriatric Hospital & Institute of Gerontology, Itabashi-ku, Tokyo 173-0015, Japan.
Shigeo
S
Murayama
Department of Neuropathology (Brain Bank for Aging Research), Tokyo Metropolitan Geriatric Hospital & Institute of Gerontology, Itabashi-ku, Tokyo 173-0015, Japan; Department of Neurology and Cerebrovascular Medicine, Saitama International Medical Center, Saitama Medical University, Hidaka, Saitama 350-1298, Japan; Department of Neurology, Mihara Memorial Hospital, Isesaki, Gunma 372-0006, Japan.
Masaki
M
Takao
Department of Developmental Physiology, National Institute for Physiological Sciences (NIPS), National Institutes of Natural Sciences, Okazaki, Aichi 444-8585, Japan; Department of Neuroscience, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan.
Tadashi
T
Isa
Human Informatics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Umezono, Tsukuba, Ibaraki 305-8568, Japan. Electronic address: n.higo@aist.go.jp.
Noriyuki
N
Higo
D000368:Aged; D000369:Aged, 80 and over; D000690:Amyotrophic Lateral Sclerosis / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000378:metabolism / Q000473:pathology; D009046:Motor Neurons / Q000378:metabolism / Q000473:pathology; D053495:Osteopontin / Q000378:metabolism*; D017966:Pyramidal Cells / Q000378:metabolism / Q000473:pathology; D066191:Sensorimotor Cortex / Q000378:metabolism* / Q000473:pathology; D013116:Spinal Cord / Q000378:metabolism* / Q000473:pathology
C506895:SPP1 protein, human; D053495:Osteopontin
Corticospinal neuron; Degeneration; Immunohistochemistry; Motor neuron; Primary somatosensory cortex; Spinal ventral horn