. Cluzeau et al., 2012 demonstrated that Lgals3 and Ctsd transcripts reduced in response to HbCD in Npc12/2 mice. We show that lysozyme levels decrease in 
plasma in response to HbCD in mice carrying a point mutation in NPC1. Together, these data strongly validate our predictions of lysosomal, secretory innate immune proteins alone or in combination, may provide useful surrogate disease markers for NPC in plasma. As indicated earlier, many are also up regulated in other lysosomal disorders, suggesting they may also developed as pan or specific plasma markers for neurological diseases associated with lysosomal storage and where diagnosis is a major problem. To further validate our gene expression data we compared them to prior gene expression studies undertaken in NPC whole animals and/or cultured cells. Since NPC is a lipid storage disease, we examined whether there were changes in genes related to metabolism of lipids and fatty acids. Indeed, 180 genes and 117 genes were respectively linked to lipid and fatty acid metabolism. This is consistent with prior analysis of single time points analyzed from Npc12/2 mice. In contrast, we found no major changes in Liver X receptor pathways which regulate levels of cellular cholesterol but consistent with prior reports that there is no significant activation Elevation of Innate Immunity in NPC Disease of LXR genes in NPC organs. As exception, Abcg1, Lpl and Pltp were slightly elevated, but this was also noted by Cluzeau et al., 2012. Prior gene expression analyses in the brain by qPCR, revealed over expression of genes involved in extracellular cholesterol trafficking, intracellular cholesterol trafficking, sterol synthesis and metabolism and cell abundance . Our data suggest that other than Npc2 and Gfap, none were consistently up regulated across the animal life span in the brain. However inflammatory genes such as Cd68, Itgax, Itgb2, C3ar1, Cd44, Cyba, Fcgr2b, Grn, Ptprc etc were consistently up regulated in NPC brain. Genes related to calcium regulation and oxidative stress reported in cell culture studies were also consistently up regulated in the liver of NPC mice. Cluzeau et al., 2012 reported age dependent expression of 18 genes in the liver. Our study confirms 14 out of 18 genes showing good correspondence between the two data sets in the liver. These genes correspond to pathways of lipid homeostasis, cell adhesion and extracellular remodeling, immune response and inflammation, developmental signaling, oxidative stress, synaptic plasticity . Lysozyme is a small, stable protein present in blood as well as additional secretions like saliva and thus particularly suited to being developed as a simple disease test. Elevation of lysozyme in both Npc1nih and Npc1nmf mice strongly suggest that secretory lysosomal protein markers may be associated with both R-547 severe and milder disease progression as observed in patients. Additionally, plasma lysozyme levels provide a simple test to follow the effectiveness of a drug in mouse models of NPC. Curiously, although transcript levels of lysozyme continue to increase with age in both brain and liver, the enzymatic activity of lysozyme plateaus at later 10884520 stages in both the Npc1nih and Npc1nmf models. One possibility is that as the disease becomes severe, lysozyme protein denatures and loses its activity due to prolonged oxidative stress, but this will require additional study. Nonetheless, at a 9874164 minimum, lysozyme activity provides a useful marker in preclinica
