title: Neuronal and epithelial cell rescue resolves chronic systemic inflammation in the lipid storage disorder Niemann-Pick C.
abstract: Chronic systemic inflammation is thought to be a major contributor to metabolic and neurodegenerative diseases. Since inflammatory components are shared among different disorders, targeting inflammation is an attractive option for mitigating disease. To test the significance of inflammation in the lipid storage disorder (LSD) Niemann-Pick C (NPC), we deleted the macrophage inflammatory gene Mip1a/Ccl3 from NPC diseased mice. Deletion of Ccl3 had been reported to delay neuronal loss in Sandhoff LSD mice by inhibiting macrophage infiltration. For NPC mice, in contrast, deleting Ccl3 did not retard neurodegeneration and worsened the clinical outcome. Depletion of visceral tissue macrophages also did not alter central nervous system (CNS) pathology and instead increased liver injury, suggesting a limited macrophage infiltration response into the CNS and a beneficial role of macrophage activity in visceral tissue. Prevention of neuron loss or liver injury, even at late stages in the disease, was achieved through specific rescue of NPC disease in neurons or in liver epithelial cells, respectively. Local epithelial cell correction was also sufficient to reduce the macrophage-associated pathology in lung tissue. These results demonstrate that elevated inflammation and macrophage activity does not necessarily contribute to neurodegeneration and tissue injury, and LSD defects in immune cells may not preclude an appropriate inflammatory response. We conclude that inflammation remains secondary to neuronal and epithelial cell dysfunction and does not irreversibly contribute to the pathogenic cascade in NPC disease. Without further exploration of possible beneficial roles of inflammatory mediators, targeting inflammation may not be therapeutically effective at ameliorating disease severity.
authors.affiliation: Department of Developmental Biology, Howard Hughes Medical Institute, Stanford University School of Medicine Clark Center, 318 Campus Drive, Stanford, CA 94305-5439, USA
authors.forename: Manuel E
authors.initials: ME
authors.lastname: Lopez
authors.forename: Andrés D
authors.initials: AD
authors.lastname: Klein
authors.forename: Jennifer
authors.initials: J
authors.lastname: Hong
authors.forename: Ubah J
authors.initials: UJ
authors.lastname: Dimbil
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Scott
mesh_terms: D000818:Animals; D002490:Central Nervous System / Q000276:immunology / Q000473:pathology; D054405:Chemokine CCL3 / Q000096:biosynthesis / Q000172:deficiency / Q000235:genetics*; D004195:Disease Models, Animal; D004847:Epithelial Cells / Q000473:pathology; D007249:Inflammation / Q000235:genetics / Q000473:pathology*; D047908:Intracellular Signaling Peptides and Proteins; D008099:Liver / Q000276:immunology / Q000473:pathology; D008264:Macrophages / Q000502:physiology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009410:Nerve Degeneration; D009474:Neurons / Q000473:pathology*; D000077296:Niemann-Pick C1 Protein; D052556:Niemann-Pick Disease, Type C / Q000235:genetics / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D011506:Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: C496534:Ccl3 protein, mouse; D054405:Chemokine CCL3; D047908:Intracellular Signaling Peptides and Proteins; D000077296:Niemann-Pick C1 Protein; C106831:Npc1 protein, mouse; D011506:Proteins