Altered expression of metabolic proteins and adipokines in patients with amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is an adult-onset neurodegenerative disease characterized by the loss of upper cortical and lower motor neurons. ALS causes death within 2-5years of diagnosis. Diet and body mass index influence the clinical course of disease, however there is limited information about the expression of metabolic proteins and fat-derived cytokines (adipokines) in ALS. In healthy controls and subjects with ALS, we have measured levels of proteins and adipokines that influence metabolism. We find altered levels of active ghrelin, gastric inhibitory peptide (GIP), pancreatic polypeptide (PP), lipocalin-2, plasminogen activator inhibitor-1 (PAI-1), interleukin-6 (IL-6) and 8 (IL-8), and tumor necrosis factor alpha (TNFα) in the plasma of ALS patients relative to controls. We also observe a positive correlation between the expression of plasma nerve growth factor (NGF) relative to disease duration, and an inverse correlation between plasma glucagon and the ALS functional rating scale-revised (ALSFRS-R). Further studies are required to determine whether altered expression of metabolic proteins and adipokines contribute to motor neuron vulnerability and how these factors act to modify the course of disease.

Elevation of the terminal complement activation products C5a and C5b-9 in ALS patient blood.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease, characterized by the progressive loss of motor neurons within the central nervous system. Neural degeneration and inflammatory processes, including activation of the complement system are hallmarks of this pathology. Our past work in ALS animal models (hSOD1 G93A rodents) has revealed that blockade of the receptor for complement activation fragment C5a (C5aR), improves ALS-like symptoms and extends survival. We now show that the levels of C5a and C5b-9, but not C3a nor C4a, are significantly elevated in plasma from ALS patients compared to healthy controls. C5a was also elevated within leukocytes from ALS patients suggesting heightened C5a receptor interaction. Overall, these findings indicate that there is enhanced peripheral immune complement terminal pathway activation in ALS, which may have relevance in the disease process.

Reduced levels of interleukin 33 and increased levels of soluble ST2 in subjects with amyotrophic lateral sclerosis.

Interleukin 33 (IL-33) is a cytokine that functions as an alarmin and is released from damaged tissue. The receptor for IL-33 is ST2, which exists as membrane bound and soluble forms. Levels of IL-33 and soluble ST2 (sST2) are elevated in some inflammatory diseases. Amyotrophic lateral sclerosis (ALS) is a disease that is due to loss of motor neurones, with some neuro-inflammation at the site of pathology. This study was performed to measure levels of IL-33 and sST2 in ALS. Serum was obtained from subjects with ALS (n=42) and healthy controls (n=38). Levels of IL-33 and s ST2 were measured with ELISA. The level of Il-33 was significantly lower in ALS subjects than healthy controls, and the levels of sST2 were significantly higher. The lower levels of IL-33 could be due to degradation of IL-33 by caspases released from apoptotic cells. However the levels of IL-33 could also be lower due to effects of sST2 which acts as a receptor for IL-33. The levels of sST2 could reflect inflammation in ALS.

Decreased T cell reactivity to Epstein-Barr virus infected lymphoblastoid cell lines in multiple sclerosis.

OBJECTIVE: To investigate T cell and antibody immunity to Epstein-Barr virus (EBV) in multiple sclerosis (MS). METHODS: Immunoglobulin G (IgG) immunity to EBV nuclear antigen 1 (EBNA1) and viral capsid antigen was measured by enzyme linked immunosorbent assays, and T cell immunity was assessed using enzyme linked immunospot assays to measure the frequency of peripheral blood mononuclear cells (PBMC) producing interferon gamma in response to autologous EBV infected B cell lymphoblastoid cell lines (LCL) in 34 EBV seropositive healthy subjects and 34 EBV seropositive patients with MS who had not received immunomodulatory therapy in the previous 3 months. RESULTS: Patients with MS had increased levels of anti-EBNA1 IgG but a decreased frequency of LCL specific T cells compared with healthy subjects. Using purified populations of CD4(+) T cells and CD8(+) T cells, we showed that the LCL specific response resides predominantly in the CD8(+) population, with a frequency 5-7-fold higher than in the CD4(+) population. The decreased CD8(+) T cell response to LCL in MS was not caused by decreased HLA class I expression by LCL, and LCL from MS patients could be killed normally by HLA matched EBV specific cytotoxic CD8(+) T cell clones from healthy subjects. Furthermore, the decreased CD8(+) T cell immunity to EBV was not due to a primary defect in the function of CD8(+) T cells because EBV specific cytotoxic CD8(+) T cell lines could be generated normally from the PBMC of patients with MS. CONCLUSION: This quantitative deficiency in CD8(+) T cell immunity to EBV might be responsible for the accumulation of EBV infected B cells in the brains of patients with MS.