Neuronal ceroid lipofuscinosis (NCL) comprises ∼13 genetically distinct lysosomal disorders primarily affecting the central nervous system. Here we report successful reprograming of patient fibroblasts into induced pluripotent stem cells (iPSCs) for the two most common NCL subtypes: classic late-infantile NCL, caused by TPP1(CLN2) mutation, and juvenile NCL, caused by CLN3 mutation. CLN2/TPP1- and CLN3-iPSCs displayed overlapping but distinct biochemical and morphological abnormalities within the endosomal-lysosomal system. In neuronal derivatives, further abnormalities were observed in mitochondria, Golgi and endoplasmic reticulum. While lysosomal storage was undetectable in iPSCs, progressive disease subtype-specific storage material was evident upon neural differentiation and was rescued by reintroducing the non-mutated NCL proteins. In proof-of-concept studies, we further documented differential effects of potential small molecule TPP1 activity inducers. Fenofibrate and gemfibrozil, previously reported to induce TPP1 activity in control cells, failed to increase TPP1 activity in patient iPSC-derived neural progenitor cells. Conversely, nonsense suppression by PTC124 resulted in both an increase of TPP1 activity and attenuation of neuropathology in patient iPSC-derived neural progenitor cells. This study therefore documents the high value of this powerful new set of tools for improved drug screening and for investigating early mechanisms driving NCL pathogenesis.

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Mounting evidence in humans supports an etiological role for the microbiota in inflammatory atherosclerosis. Atherosclerosis is a progressive disease characterized by accumulation of inflammatory cells and lipids in vascular tissue. While retention of lipoprotein into the sub-endothelial vascular layer is believed to be the initiating stimulus leading to the development of atherosclerosis, activation of multiple pathways related to vascular inflammation and endothelial dysfunction sustain the process by stimulating recruitment of leukocytes and immune cells into the sub-endothelial layer. The Gram-negative oral pathogen Porphyromonas gingivalis has been associated with the development and acceleration of atherosclerosis in humans and these observations have been validated in animal models. It has been proposed that common mechanisms of immune signaling link stimulation by lipids and pathogens to vascular inflammation. Despite the common outcome of P. gingivalis and lipid feeding on atherosclerosis progression, we established that these pro-atherogenic stimuli induced distinct gene signatures in the ApoE-/- mouse model of atherosclerosis. In this study, we further defined the distinct roles of dietary lipids and P. gingivalis infection on atherosclerosis progression and the gut microbiota. We demonstrate that diet-induced lipid lowering resulted in less atherosclerotic plaque in ApoE-/- mice compared to ApoE-/- mice continuously fed a Western diet. However, the effect of diet-induced lipid lowering on plaque accumulation was blunted by P. gingivalis infection. Using principal component analysis and hierarchical clustering, we demonstrate that dietary intervention as well as P. gingivalis infection result in distinct bacterial communities in fecal and cecal samples of ApoE-/- mice as compared to ApoE-/- mice continuously fed either a Western diet or a normal chow diet. Collectively, we identified distinct microbiota changes accompanying atherosclerotic plaque, suggesting a future avenue for investigation on the impact of the gut microbiota, diet, and P. gingivalis infection on atherosclerosis.