Lectin-Positive Spherical Deposits (SPD) Detected in the Molecular Layer of Hippocampal Dentate Gurus of Dementia, Down’s Syndrome, and Schizophrenia

Lectins are proteins which specifically bind (or crosslink) carbohydrates. Recent studies have shown the importance of glycosylation in pathogenesis of diseases. Lectin-positive spherical deposits (SPD), 3-10 micron in diameter, have been detected in the molecular layer of dentate gyrus of hippocampus in dementia, Down’s syndrome, and schizophrenia. In schizophrenia, SPD was observed without exception, regardless of having history of pharmacotherapy. Multi-labeling histochemical methods, revealed that single strand DNA was co-localized in hippocampal SPD of schizophrenia with lectin, including GSI-B4 for galactose, and UEA-I for fucose, suggesting that SPD formation in schizophrenia is related to apoptotic process. The molecular basis of SPD formation should detailly investigated in brains with neuropsychiatric illnesses, including Alzheimer’s disease and Parkinson’s disease. spherical deposits (SPD) in the molecular layer of hippocampal dentate gyrus of schizophrenia (Figures 1-3), dementia, and Down’s syndrome (Figure 4) [4]. In the present mini-review, possible nature and pathophysiological significance of lectin-positive SPD would be introduced. Spherical Deposits (SPD) in the Molecular Layer of Hippocampal Dentate Gyrus Lectin immunohistochemistry using various antibodies that detects carbohydrates (Table 1), combined with conventional staining methods, revealed SPD, 3-10 micron in diameter, in the molecular layer of the dentate gyrus of the hippocampal formation (Figures 1-3) from patients with Alzheimer’s disease (dementia of Alzheimer type), dementia with tangles, Down’ s syndrome and schizophrenia, and aged individuals (Figure 4) [2]. The lectin-positive SPD did not show immunoreactivity for antibodies against ubiquitin and tau-protein, though the corpora amylacea showed clear immunoreactivity for these substances (Figure 1D-b) [4]. The SPD contained fucose (α-Fuc), galactose (α-Gal) (Figures 2C, 6), N-acetyl galactosamine (α-GalNAc) (Figure 5), N-acetyl glucosamine (GlcNAc), sialic acid, mannose (Man) and chondroitin sulfate (Figure 1D-a), suggesting that there might be unusual glycometabolism (Table 1), possibly related to the process *Corresponding author: Keiko Ikemoto, Department of Psychiatry, Iwaki Kyoritsu General Hospital, Iwaki, 973-8555, Japan, Tel: +90-4869-4135; E-mail: [email protected] Received July 26, 2014; Accepted November 10, 2014; Published November 17, 2014 Citation: Ikemoto K, Nishimura A, Nishi K (2014) Lectin-Positive Spherical Deposits (SPD) Detected in the Molecular Layer of Hippocampal Dentate Gyrus of Dementia, Down’s Syndrome, and Schizophrenia. J Alzheimers Dis Parkinsonism 4: 169. doi: 10.4172/2161-0460.1000169 Copyright: © 2014 Ikemoto K, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Lectin and antibodies Abbreviation Carbohydrate binding specificity Archis hypogaea agglutinin PNA Gal(β1,3)GalNAc Canavalia ensiformis agglutinin Con A Branched α-Man ( Manα1-6 (Manα1-3) Man ) Datura stramonium DSA GlcNAc Dolichos biflorus agglutinin DBA α-GalNAc Erythrina cristagalli ECA Gal(β1,3)GlcNAc Glycine max agglutinin SBA GalNAc(α1,3)Gal Griffonia simplicifolia iso agglutinin I-B4 GSI-B4 α-Gal Pisum sativum agglutinin PSA Fuc(α1,6)Glc, α-Man Triticum vulgare WGA Manβ(1,4)GlcNAc(1,4) GlcNAc Ulex europaeus agglutinin UEA-I α-Fuc Table 1: Interaction between lectins and antibodies, abbreviation, and the carbohydrate binding specificity is shown. Citation: Ikemoto K, Nishimura A, Nishi K (2014) Lectin-Positive Spherical Deposits (SPD) Detected in the Molecular Layer of Hippocampal Dentate Gyrus of Dementia, Down’s Syndrome, and Schizophrenia. J Alzheimers Dis Parkinsonism 4: 169. doi: 10.4172/2161-0460.1000169