摘要
Mitochondrial diseases are caused by variants in both mitochondrial and nuclear genomes.A nuclear gene HPDL(4-hydroxyphenylpyruvate dioxygenase-like),which encodes an intermembrane mitochondrial protein,has been recently implicated in causing a neurodegenerative disease characterized by pediatric-onset spastic movement phenotypes.Here,we report six Chinese patients with bi-allelic HPDL pathogenic variants from four unrelated families showing neuropathic symptoms of variable severity,including developmental delay/intellectual disability,spasm,and hypertonia.Seven different pathogenic variants are identified,of which five are novel.Both fibroblasts and immortalized lymphocytes derived from patients show impaired mitochondrial respiratory function,which is also observed in HPDL-knockdown(KD)He La cells.In these He La cells,overexpression of a wild-type HPDL gene can rescue the respiratory phenotype of oxygen consumption rate.In addition,a decreased activity of the oxidative phosphorylation(OXPHOS)complex II is observed in patient-derived lymphocytes and HPDL-KD He La cells,further supporting an essential role of HPDL in the mitochondrial respiratory chain.Collectively,our data expand the clinical and mutational spectra of this mitochondrial neuropathy and further delineate the possible disease mechanism involving the impairment of the OXPHOS complex II activity due to the bi-allelic inactivations of HPDL.
基金
funded by the Precision Medical Research of National Key Research and Development Program(2018YFC1002200,2019YFC1005100 to Y.Yu,2018YFC1002400 to Y.Sun,and 2018YFC1002501 to Y.Shen)
National Natural Science Foundation of China(81873633 and 82071276 to Y.Shen,81830071 to J.Lyu,81873724 to Y.Sun,and 82070914 and 81873671 to Y.Yu)
Shanghai Shen Kang Hospital Development Center(SHDC12017109 to Y.Yu)
the Shanghai Science and Technology Commission(19140904500 to Y.Yu)
Jiaotong University Cross Biomedical Engineering(YG2017MS72 to Y.Yu)
the“Eastern Scholar”Fund
the“Guangxi Bagui Scholar”fund(to Y.Shen)
the Major Research Plan of the Provincial Science and Technology Foundation of Guangxi(AB16380214 to Y.Shen)
Foundation of Shanghai Municipal Health Commission(shslczdzk05702,to Y.Yu and Y.Sun)
Municipal Education Commission-Gaofeng Clinical Medicine Grant Support(20191908,to Y.Yu)。
