ABSTRACT
Olfactory dysfunction is one of the prodromal symptoms in dementia with Lewy bodies (DLB). However, the molecular pathogenesis associated with decreased smell function remains largely undeciphered. We generated quantitative proteome maps to detect molecular alterations in olfactory bulbs (OB) derived from DLB subjects compared to neurologically intact controls. A total of 3214 olfactory proteins were quantified, and 99 proteins showed significant alterations in DLB cases. Protein interaction networks disrupted in DLB indicated an imbalance in translation and the synaptic vesicle cycle. These alterations were accompanied by alterations in AKT/MAPK/SEK1/p38 MAPK signaling pathways that showed a distinct expression profile across the OB-olfactory tract (OT) axis. Taken together, our data partially reflect the missing links in the biochemical understanding of olfactory dysfunction in DLB.
Subject(s)
Alzheimer Disease/complications , Biomarkers/metabolism , Lewy Body Disease/complications , Olfactory Nerve Diseases/diagnosis , Proteome/analysis , Proteome/metabolism , Aged , Aged, 80 and over , Case-Control Studies , Disease Progression , Female , Humans , Male , Olfactory Nerve Diseases/etiology , Olfactory Nerve Diseases/metabolismABSTRACT
Olfactory ensheathing cells are glial cells located in the olfactory bulb and nerve. Microscopically, both olfactory ensheathing cells and Schwann cells have similar morphological and immunohistochemical features. However, olfactory ensheathing cells are negative for Leu-7(CD-57), whereas Schwann cells are positive. We present the case of a 49 year-old male with a history of visual impairment and hyposmia. Radiological CT and MRI studies showed a subfrontal cystic extra-axial mass, which eroded the right cribriform plate, with heterogeneous contrast enhancement. Total excision of the tumour was performed by bifrontal craniotomy. Histological examination initially suggested a schwannoma, with immunohistochemical staining being positive for S-100 protein and negative for epithelial membrane antigen (EMA). However, the tumour was negative for Leu-7. Accordingly, the final diagnosis was olfactory ensheathing cell tumour. Herein, we describe the sixth case of intracranial olfactory ensheathing cell tumour and stress the important role of immunohistochemical techniques in obtaining a definitive diagnosis.
