Elevated alpha-synuclein impairs innate immune cell function and provides a potential peripheral biomarker for Parkinson's disease.

Alpha-synuclein protein is strongly implicated in the pathogenesis Parkinson's disease. Increased expression of α-synuclein due to genetic multiplication or point mutations leads to early onset disease. While α-synuclein is known to modulate membrane vesicle dynamics, it is not clear if this activity is involved in the pathogenic process or if measurable physiological effects of α-synuclein over-expression or mutation exist in vivo. Macrophages and microglia isolated from BAC α-synuclein transgenic mice, which overexpress α-synuclein under regulation of its own promoter, express α-synuclein and exhibit impaired cytokine release and phagocytosis. These processes were affected in vivo as well, both in peritoneal macrophages and microglia in the CNS. Extending these findings to humans, we found similar results with monocytes and fibroblasts isolated from idiopathic or familial Parkinson's disease patients compared to age-matched controls. In summary, this paper provides 1) a new animal model to measure α-synuclein dysfunction; 2) a cellular system to measure synchronized mobilization of α-synuclein and its functional interactions; 3) observations regarding a potential role for innate immune cell function in the development and progression of Parkinson's disease and other human synucleinopathies; 4) putative peripheral biomarkers to study and track these processes in human subjects. While altered neuronal function is a primary issue in PD, the widespread consequence of abnormal α-synuclein expression in other cell types, including immune cells, could play an important role in the neurodegenerative progression of PD and other synucleinopathies. Moreover, increased α-synuclein and altered phagocytosis may provide a useful biomarker for human PD.

PEG conjugates of potent α4 integrin inhibitors, maintaining sustained levels and bioactivity in vivo, following subcutaneous administration.

Mitsunobu reactions were employed to link t-butyl esters of α4 integrin inhibitors at each of the termini of a three-arm, 40 kDa, branched PEG. Cleavage of the t-butyl esters using HCO2H provided easily isolated PEG derivatives, which are potent α4 integrin inhibitors, and which achieve sustained levels and bioactivity in vivo, following subcutaneous administration to rats.

Laminin-411 is a vascular ligand for MCAM and facilitates TH17 cell entry into the CNS.

TH17 cells enter tissues to facilitate pathogenic autoimmune responses, including multiple sclerosis (MS). However, the adhesion molecules involved in the unique migratory capacity of TH17 cells, into both inflamed and uninflamed tissues remain unclear. Herein, we characterize MCAM (CD146) as an adhesion molecule that defines human TH17 cells in the circulation; following in vitro restimulation of human memory T cells, nearly all of the capacity to secrete IL-17 is contained within the population of cells expressing MCAM. Furthermore, we identify the MCAM ligand as laminin 411, an isoform of laminin expressed within the vascular endothelial basement membranes under inflammatory as well as homeotstatic conditions. Purified MCAM-Fc binds to laminin 411 with an affinity of 27 nM, and recognizes vascular basement membranes in mouse and human tissue. MCAM-Fc binding was undetectable in tissue from mice with targeted deletion of laminin 411, indicating that laminin 411 is a major tissue ligand for MCAM. An anti-MCAM monoclonal antibody, selected for inhibition of laminin binding, as well as soluble MCAM-Fc, inhibited T cell adhesion to laminin 411 in vitro. When administered in vivo, the antibody reduced TH17 cell infiltration into the CNS and ameliorated disease in an animal model of MS. Our data suggest that MCAM and laminin 411 interact to facilitate TH17 cell entry into tissues and promote inflammation.

Non-viral delivery of nuclear factor-kappaB decoy ameliorates murine inflammatory bowel disease and restores tissue homeostasis.

BACKGROUND: Nuclear factor-kappaB (NF-kappaB) is a key transcriptional regulator of inflammatory bowel disease (IBD). AIM: To investigate the therapeutic potential of a locally administered "non-viral" nuclear factor-kappaB decoy (NFkappaBD) in multiple experimental models of IBD. METHODS: A fully phosphorothioated decoy oligonucleotide with improved stability that specifically binds NF-kappaB and blocks inflammatory mediators regulated by this transcription factor without the help of viral envelope-assisted delivery was developed. The therapeutic effects of NFkappaBD were studied in the trinitrobenzene sulphonic acid, oxazolone and dextran sodium sulphate induced colitis models. RESULTS: Intracolonic administration of NFkappaBD results in the delivery of NFkappaBD to inflammatory cells and a reduction of NF-kappaB heterodimers. In the T helper cell 1-driven trinitrobenzene sulphonic acid-induced colitis model, mice receiving NFkappaBD treatment exhibit a dose-dependent reduction in disease severity and a more rapid recovery to normal body weight, similar to a clinically relevant dose of budesonide. Clinical efficacy was corroborated by considerable reductions in colitis pathology and tissue levels of several pro-inflammatory markers, including tumour necrosis factor alpha, interleukin 6, interleukin 1beta and monocyte chemotactic protein 1. NFkappaBD also mitigates disease activity in the T helper cell 2-like oxazolone colitis and epithelial injury-related acute dextran sodium sulphate colitis models. Interestingly, restoration of tissue homeostasis is observed in NFkappaBD-treated animals with the rapid re-emergence of functional goblet cells and a return to normal patterns of cell proliferation in the mucosal epithelium and smooth muscle cell layers. CONCLUSIONS: These data support the potential use of "naked" NFkappaBD as a cross-functional therapeutic in IBD, and show for the first time that it can facilitate the restoration of colon homeostasis and function.