Pericytes in Neurometabolic Diseases

Abstract

Since brain pericytes guarantee appropriate development and maintenance of the cerebrovascular system, we reviewed their role in neurometabolic diseases (NMDs), a subclass of inborn errors of metabolism that selectively cause neurological sequels and widespread cerebrovascular alterations. Main findings about pericyte involvement in NMDs arise from glutaric acidemia type I (GA-I) models. In this regard, we found that (i) a single intracisternal injection of the main accumulated metabolite (glutaric acid, GA) in rat neonates disturbed the neurovascular unit (NVU) as evidenced by blood-brain barrier hyperpermeability, and altered immunoreactivity of pericyte and astrocyte markers surrounding brain microvessels; (ii) GA-elicited capillary constriction near pericyte somata likely inducing reduced brain blood flow as reported in GA-I patients; (iii) GA-elicited pericyte contraction probably results from a defective interplay among NVU components and could be relevant in case of metabolic decompensation or energetic deficiency. Although pericyte pathological features have been studied in few NMDs, their involvement in NMD pathophysiology is largely unknown. Thus, further studies are needed to identify their roles and therapeutic potentiality.