Faculty Bibliography

BACKGROUND:The balance between T helper cells Th2- and Th1-related cytokines plays a key role in multiple sclerosis (MS). A shift from a Th1 towards a Th2 cytokine profile could have a beneficial effect on the clinical course of the disease. The objective of this study was to assess Th2/Th1 cytokine profile in relapsing-remitting MS (RRMS) patients receiving an immunosuppressive treatment with natalizumab (NAT), or an immunomodulatory treatment with glatiramer acetate (GA) after one year of treatment. METHODS:This was an observational cross-sectional study. All consecutive patients diagnosed with RRMS who had received GA or NAT for 12 months were included in the study. We determined serum levels of Th1 and Th2 cytokines (interleukin [IL]-1a, IL-1b, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, IL-13, monocyte chemotactic protein [MCP]-1, tumor-necrosis factor [TNF]-α, interferon [IFN]-γ and granulocyte macrophage colony stimulating factor [GM-CSF]) by flow cytometry. Th2/Th1 bias was defined based on the ratio of IL-4, IL-5, IL-6 or IL-10 Th2 cytokines and proinflammatory INF-γ or TNF-α Th1 cytokines. RESULTS:Eleven patients under treatment with NAT and 12 patients treated with GA were evaluated. RRMS patients treated with NAT showed significantly higher levels of IL-6 (p < 0.05), MCP-1 (p < 0.01), and GM-CSF (p < 0.05) compared to GA patients after one year of treatment. A trend for increasing of IL-12p70, IL-1b, TNF- α and IFN- γ levels was also found in patients receiving NAT compared to GA patients. IL-4/IFN-γ, IFN-γ/TNF-α and IL-10/IFN-γ ratios as markers of Th2/Th1 ratio were significantly elevated in GA patients compared to those receiving NAT (p < 0.05). CONCLUSION/CONCLUSIONS:In conclusion, our findings suggest that GA promotes a superior Th2-biased anti-inflammatory response as compared with NAT in the systemic circulation of RRMS patients. Future studies with larger cohorts will determine whether this immune Th2 shift in GA patients is associated with a beneficial effect on disease outcome.

Use of thrombolysis in acute ischaemic stroke may be limited by a narrow benefit/risk ratio. Pharmacological inhibition of the ischaemic cascade may constitute an effective and safer approach to stroke treatment. This study compared the effects of high doses of cytidine diphosphate-choline (CDP-choline; 1000 mg/kg) with recombinant tissue plasminogen activator (rt-PA; 5 mg/kg) in an experimental animal model of embolic stroke. Fifteen rats were embolized in the right internal carotid artery with an autologous clot and were divided into three groups: (1) infarct; (2) intravenous rt-PA 5 mg/kg 30 minutes post-embolization; and (3) CDP-choline 1000 mg/kg, intraperitoneal, three doses, 30 minutes, 24 hours, and 48 hours post-embolization. Functional evaluation scores were evaluated using Rogers test, lesion volume by haematoxylin and eosin staining, cell death with transferase-mediated dUTP nick-end labelling, and plasma levels of interleukin-6 (IL-6) and tumor necrosis factor-alpha with enzyme-linked immunosorbent assay. In this study, CDP-choline and rt-PA produced a significant reduction in brain damage considering infarct volume, cell death, and inflammatory cytokines (tumour necrosis factor-alpha and IL-6) compared with the infarct group. Additionally, CDP-choline significantly decreased infarct volume, cell death, and IL-6 levels with respect to the rt-PA group. From these results, we conclude that high-dose CDP-choline may be an effective treatment for acute ischaemic stroke even in absence of thrombolysis.

BACKGROUND:A large number of genes are regulated to promote brain repair following stroke. The thorough analysis of this process can help identify new markers and develop therapeutic strategies. This study analyzes gene expression following experimental stroke. METHODOLOGY/PRINCIPAL FINDINGS/RESULTS:A microarray study of gene expression in the core, periinfarct and contralateral cortex was performed in adult Sprague-Dawley rats (n = 60) after 24 hours (acute phase) or 3 days (delayed stage) of permanent middle cerebral artery (MCA) occlusion. Independent qRT-PCR validation (n = 12) was performed for 22 of the genes. Functional data were evaluated by Ingenuity Pathway Analysis. The number of genes differentially expressed was 2,612 (24 h) and 5,717 (3 d) in the core; and 3,505 (24 h) and 1,686 (3 d) in the periinfarct area (logFC>|1|; adjP<0.05). Expression of many neurovascular unit development genes was altered at 24 h and 3 d including HES2, OLIG2, LINGO1 and NOGO-A; chemokines like CXCL1 and CXCL12, stress-response genes like HIF-1A, and trophic factors like BDNF or BMP4. Nearly half of the detected genes (43%) had not been associated with stroke previously. CONCLUSIONS:This comprehensive study of gene regulation in the core and periinfarct areas at different times following permanent MCA occlusion provides new data that can be helpful in translational research.

Natalizumab is a widely accepted drug for the relapsing-remitting subtype of multiple sclerosis (RRMS). The present longitudinal exploratory study in RRMS patients analyzes the effects of natalizumab treatment on the levels of pro-inflammatory and anti-inflammatory cytokine protein levels and also the frequency and suppressor function of regulatory T cells. Flow cytometry was used to determine cytokines and regulatory T cell frequency while regulatory T cell suppressor function was assayed in vitro at different time-points after starting with natalizumab. Results showed serum levels of pro-inflammatory interferon gamma and interleukin (IL)-12p70, as well as anti-inflammatory IL-4 and IL-10, were elevated just a few hours or days after first IV infusion of natalizumab. Interestingly, other cytokines like IL-5 or IL-13 were also elevated while pro-inflammatory IL-17, IL-2, and IL-1β increased only after a long-term treatment, suggesting different immune mechanisms. In contrast, we did not observe any effect of natalizumab treatment on regulatory T cell frequency or activity. In conclusion, these results suggest natalizumab has other immunological effects beyond VLA-4 interaction and inhibition of CNS extravasation, the relevance of which is as yet unknown and warrants further investigation.