Parainflammation, chronic inflammation, and age‐related macular degeneration

摘要

Inflammationisanadaptiveresponseoftheimmunesystemtonoxiousinsultstomaintainhomeostasisandrestorefunctionality.Theretinaisconsideredanimmune‐privilegedtissueasaresultofitsuniqueanatomicandphysiologicproperties.Duringaging,theretinasuffersfromalow‐gradechronicoxidativeinsult,whichsustainsfordecadesandincreasesinlevelwithadvancingage.Asaresult,theretinalinnate‐immunesystem,particularlymicrogliaandthecomplementsystem,undergoeslowlevelsofactivation(parainflammation).Inmanycases,thisparainflammatoryresponsecanmaintainhomeostasisinthehealthyagingeye.However,inpatientswithage‐relatedmaculardegeneration,thisparainflammatoryresponsebecomesdysregulatedandcontributestomaculardamage.Factorscontributingtothedysregulationofage‐relatedretinalparainflammationincludegeneticpredisposition,environmentalriskfactors,andoldage.Dysregulatedparainflammation(chronicinflammation)inage‐relatedmaculardegenerationdamagesthebloodretinabarrier,resultinginthebreachofretinal‐immuneprivilege,leadingtothedevelopmentofretinallesions.Thisreviewdiscussesthebasicprinciplesofretinalinnate‐immuneresponsestoendogenouschronicinsultsinnormalagingandinage‐relatedmaculardegenerationandexploresthedifferencebetweenbeneficialparainflammationandthedetrimentalchronicinflammationinthecontextofage‐relatedmaculardegeneration...