Patient 1. Patient 1 was a 67-year-old woman. When she was 62, right-sided blindness developed over 4 days, but the vision was restored in a year. At age 65, she became quadriplegic and felt numb below the neck. After 3 months of rehabilitation, she could walk using a cane. At age 67, she developed bilateral blurred vision, paraplegia, and dysuria subacutely, …
Background: In recent years, there has been increasing evidence that several lipid metabolism abnormalities play an important role in the pathogenesis of neurodegenerative diseases. However, it is still unclear which lipid metabolism abnormalities play the most important role in neurodegenerative diseases. Plasma lipid metabolomics (lipidomics) has been shown to be an unbiased method that can be used to explore lipid metabolism abnormalities in neurodegenerative diseases. Plasma lipidomics in neurodegenerative diseases has been performed only in idiopathic Parkinson’s disease (IPD) and Alzheimer’s disease (AD), and comprehensive studies are needed to clarify the pathogenesis. Methods: In this study, we investigated plasma lipids using lipidomics in individuals with neurodegenerative diseases and healthy controls (CNs). Plasma lipidomics was evaluated by liquid chromatography-tandem mass spectrometry (LC–MS/MS) in those with IPD, dementia with Lewy bodies (DLB), multiple system atrophy (MSA), AD, and progressive supranuclear palsy (PSP) and CNs. Results: The results showed that (1) plasma sphingosine-1-phosphate (S1P) was significantly lower in all neurodegenerative disease groups (IPD, DLB, MSA, AD, and PSP) than in the CN group. (2) Plasma monohexylceramide (MonCer) and lactosylceramide (LacCer) were significantly higher in all neurodegenerative disease groups (IPD, DLB, MSA, AD, and PSP) than in the CN group. (3) Plasma MonCer levels were significantly positively correlated with plasma LacCer levels in all enrolled groups. Conclusion: S1P, Glucosylceramide (GlcCer), the main component of MonCer, and LacCer are sphingolipids that are biosynthesized from ceramide. Recent studies have suggested that elevated GlcCer and decreased S1P levels in neurons are related to neuronal cell death and that elevated LacCer levels induce neurodegeneration by neuroinflammation. In the present study, we found decreased plasma S1P levels and elevated plasma MonCer and LacCer levels in those with neurodegenerative diseases, which is a new finding indicating the importance of abnormal sphingolipid metabolism in neurodegeneration.
We studied the processing of amyloid β-peptides (Aβs) including Aβ1-40, Aβ1-42 and pAβ3-42 by rat neutral cysteine protease bleomycin hydrolase (BH) according to the methods of SDS-PAGE, HPLC and matrix-assisted laser desorption/inonization time-of-flight mass spectrometry (MALDI-TOF MS). BH significantly processed them by novel features of its diverse activities. It initially cleaved at two sites, His14-Gln15 and Phe19-Phe20 bonds, in Aβ1-40 and Aβ1-42 by endopeptidase activity. The resultant peptides were degraded to short intermediates then to amino acids by aminopeptidase and/or carboxypeptidase activities. Also, full-length Aβs were clipped at the carboxyl(C)-terminal region. On the other hand, BH cleaved at only the His14-Gln15 bond in pβA3-42 within A short period of the reaction by endopeptidase activity, and processed the intermediates in order by carboxypeptidase activity. On processing by BH, it found that both fibrillar Aβ1-40 and Aβ1-42 were more resistant than non-fibrillar peptides. These results indicate that the processing specificity of BH depends upon the structure and sequence of Aβs.