The nervous system-specific leucine-rich repeat Ig-containing protein LINGO-1 is associated with the Nogo-66 receptor complex and is endowed with a canonical EGF receptor (EGFR)-like tyrosine phosphorylation site. Our studies indicate that LINGO-1 expression is elevated in the substantia nigra of Parkinson's disease (PD) patients compared with age-matched controls and in animal models of PD after neurotoxic lesions. LINGO-1 expression is present in midbrain dopaminergic (DA) neurons in the human and rodent brain. Therefore, the role of LINGO-1 in cell damage responses of DA neurons was examined in vitro and in experimental models of PD induced by either oxidative (6-hydroxydopamine) or mitochondrial (N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) toxicity. In LINGO-1 knockout mice, DA neuron survival was increased and behavioral abnormalities were reduced compared with WT. dopamine neuron ͉ substantia nigra ͉ degeneration ͉ neuroprotection ͉ axon N ew therapeutics are required that simultaneously preserve dopamine (DA) neurons and their functional connections to limit or eliminate the progression of the movement disorder of Parkinson's disease (PD) (1, 2). Several growth factors normally active in cell growth and survival during brain development have been shown to provide protection against cell death in animal models of PD (1-5). The phosphoinositide 3-kinases (PI3-Ks) and Akt (protein kinase B) signaling pathways have been shown to participate in such growth factor actions (1, 2, 5, 6). Recent studies also suggest that some leucine-rich repeat (LRR) Ig-containing proteins can influence growth factors by modulating EGF receptor (EGFR) signaling-related pathways (7,8). LINGO-1 is a LRR-Ig protein first identified as a critical component of the NogoR1-p75NTR complex in RhoA activation, and it is responsible for some inhibition of axonal regeneration by myelin-associated factors (9, 10). Unlike NogoR1, LINGO-1 gene expression is increased when adult nerve cells are exposed to traumatic injuries (9), indicating that LINGO-1 may be involved in cell injury responses. LRRK2, another LRR protein, was recently genetically linked to PD and Lewy body disease (11, 12). As we describe here, LINGO-1 appears to regulate neurite growth and the structural integrity of neurons, in analogy with LRRK2 (9, 13).In this study, elevated LINGO-1 levels were found after selective experimental damage to DA nerve terminals in the striatum of mice, and increased expressed levels of LINGO-1 were found in the substantia nigra (SN) of some PD patients. Using methods that reduced or eliminated the negative actions of LINGO-1, we demonstrate that midbrain DA neuron survival, growth, and function improve in primary in vitro cultures and in vivo experimental models of parkinsonism in mice. We also show that LINGO-1 normally binds to EGFR and negatively regulates the EGFR/Akt signaling pathway in cells and tissues relevant to these studies. Fig. 4 B and C). LINGO-1 is expressed in remaining DA neurons in the SN of PD patients (SI Fig. 4 A and B)....

Ocular neovascularization, including age-related macular degeneration (AMD), is a primary cause of blindness in individuals of industrialized countries. With a projected increase in the prevalence of these blinding neovascular diseases, there is an urgent need for new pharmacological interventions for their treatment or prevention. Increasing evidence has implicated eicosanoid-like metabolites of long-chain polyunsaturated fatty acids (LCPUFAs) in the regulation of neovascular disease. In particular, metabolites generated by the cytochrome P450 (CYP)-epoxygenase pathway have been shown to be potent modulators of angiogenesis, making this pathway a reasonable previously unidentified target for intervention in neovascular ocular disease. Here we show that dietary supplementation with ω-3 LCPUFAs promotes regression of choroidal neovessels in a well-characterized mouse model of neovascular AMD. Leukocyte recruitment and adhesion molecule expression in choroidal neovascular lesions were down-regulated in mice fed ω-3 LCPUFAs. The serum of these mice showed increased levels of anti-inflammatory eicosanoids derived from eicosapentaenoic acid and docosahexaenoic acid. 17,18-epoxyeicosatetraenoic acid and 19,20-epoxydocosapentaenoic acid, the major CYP-generated metabolites of these primary ω-3 LCPUFAs, were identified as key lipid mediators of disease resolution. We conclude that CYP-derived bioactive lipid metabolites from ω-3 LCPUFAs are potent inhibitors of intraocular neovascular disease and show promising therapeutic potential for resolution of neovascular AMD.choroidal neovascularization | immune cell recruitment | PPARγ | adhesion molecules | epoxy-metabolites

Neovascular diseases of the eye are the most common causes of blindness worldwide. The mechanisms underlying pathological neovascularization in the retina remain incompletely understood. PGC-1α is a transcriptional coactivator that plays a central role in the regulation of cellular metabolism. In skeletal muscle, PGC-1α induces VEGFA expression and powerfully promotes angiogenesis, suggesting a similar role in other tissues. This study investigates the role of PGC-1α during normal and pathological vascularization in the retina. We show that PGC-1α induces the expression of VEGFA in numerous retinal cells, and that PGC-1α expression is strongly induced during postnatal retinal development, coincident with VEGFA expression and angiogenesis. PGC-1α(-/-) mice have a significant reduction of early retinal vascular outgrowth, and reduced density of capillaries and number of main arteries and veins as adults. In the oxygen-induced retinopathy model of retinopathy of prematurity, PGC-1α expression is dramatically induced in the inner nuclear layer of the retina, suggesting that PGC-1α drives pathological neovascularization. In support of this, PGC-1α(-/-) mice subjected to oxygen-induced retinopathy had decreased expression of VEGFA and were protected against pathological neovascularization. These results demonstrate that PGC-1α regulates VEGFA in the retina and is required for normal vessel development and for pathological neovascularization. The data highlight PGC-1α as a novel target in the treatment of neovascular diseases of the eye.

Objective-TGF-␤ plays a significant role in vascular injury-induced stenosis. This study evaluates the efficacy of a novel, small molecule inhibitor of ALK5/ALK4 kinase, in the rat carotid injury model of vascular fibrosis. Methods and Results-The small molecule, SM16, was shown to bind with high affinity to ALK5 kinase ATP binding site using a competitive binding assay and biacore analysis. SM16 blocked TGF-␤ and activin-induced Smad2/3 phosphorylation and TGF-␤-induced plasminogen activator inhibitor (PAI)-luciferase activity in cells. Good overall selectivity was demonstrated in a large panel of kinase assays, but SM16 also showed nanomolar inhibition of ALK4 and weak (micromolar) inhibition of Raf and p38. In the rat carotid injury model, SM16 dosed once daily orally at 15 or 30 mg/kg SM16 for 14 days caused significant inhibition of neointimal thickening and lumenal narrowing. SM16 also prevented induction of adventitial smooth muscle ␣-actin-positive myofibroblasts and the production of intimal collagen, but did not decrease the percentage of proliferative cells. Key Words: TGF beta Ⅲ restenosis Ⅲ fibrosis Ⅲ neointimal formation Ⅲ activin T GF-␤ promotes key cellular events in vascular fibrosis including the induction of adventitial myofibroblasts and activated smooth muscle cells as well as their proliferation, survival, contraction, and increased collagen deposition. 1 TGF-␤ is overexpressed in animal models of vascular fibrosis as well as human diseases such as restenosis, cardiac hypertrophy, primary pulmonary hypertension, and organ transplant vasculopathy. [1][2][3][4][5][6][7] Activin, another TGF-␤ superfamily member, is also upregulated during vascular remodeling after balloon injury of the rat carotid artery. 8,9 The association of overexpression of these 2 cytokines with inflammation and fibrotic responses to injury suggest that inhibition of either or both of these TGF-␤ superfamily pathways may prevent vascular fibrosis. [1][2][3][4][5][6][7][8][9][10] TGF-␤ and activin signal through binding to their respective type II receptors, TGF-␤RII and ActRII. The subsequent interaction of this complex with their respective type I receptors, ALK5 and ALK4, allows the interaction with and phosphorylation of type I receptor-associated signaling proteins, Smad2 and Smad3. 11,12 Blockade of TGF-␤ signaling with either the soluble TGF-␤ type II receptor extracellular domain-Fc fusion protein (sTGF-␤RII:Fc), 5,7 antibodies to TGF-␤1, 13 decorin, 14 TGF-␤ antisense oligonucleotides, 15-17 or adenovirus Smad7 18 was shown previously to inhibit vascular fibrosis in animal models. Here, we identified SM16, a potent, selective and orally active ALK5/ALK4 kinase inhibitor which potently inhibits TGF-␤-induced phosphorylation of Smad2 and Smad3 in cells and neointimal thickening and vascular remodeling in the rat carotid balloon injury model. This orally active, small molecule TGF-␤/activin signaling inhibitor prevents neointimal thickening and lumenal loss primarily through inhibition of myofibroblast induction a...