Scavenger receptor class B, member 2 (SCARB2) is linked to Gaucher disease and Parkinson's disease. Deficiency in the SCARB2 gene causes progressive myoclonus epilepsy (PME), a rare group of inherited neurodegenerative diseases characterized by myoclonus. We found that Scarb2 deficiency in mice leads to age-dependent dietary lipid malabsorption, accompanied with vitamin E deficiency. Our investigation revealed that Scarb2 deficiency is associated with gut dysbiosis and an altered bile acid pool, leading to hyperactivation of FXR in intestine. Hyperactivation of FXR impairs epithelium renewal and lipid absorption. Patients with SCARB2 mutations have a severe reduction in their vitamin E levels and cannot absorb dietary vitamin E. Finally, inhibiting FXR or supplementing vitamin E ameliorates the neuromotor impairment and neuropathy in Scarb2 knockout mice. These data indicate that gastrointestinal dysfunction is associated with SCARB2 deficiency-related neurodegeneration, and SCARB2-associated neurodegeneration can be improved by addressing the nutrition deficits and gastrointestinal issues.
Animals ; Mice ; Dysbiosis/metabolism* ; Mice, Knockout ; Humans ; Lysosomal Membrane Proteins/genetics* ; Receptors, Scavenger/genetics* ; Gastrointestinal Microbiome ; Myoclonic Epilepsies, Progressive/genetics* ; Vitamin E Deficiency/complications* ; Neurodegenerative Diseases/genetics* ; Bile Acids and Salts/metabolism* ; Male ; Lipid Metabolism ; Intestinal Mucosa/pathology*

Adult ; Humans ; Male ; Myoclonic Epilepsies, Progressive ; diagnostic imaging ; genetics ; therapy ; Nerve Tissue Proteins ; genetics ; Pedigree

SCARB2 (scavenger receptor class B, member 2) is a lysosomal membrane glucoprotein, which is encoded by SCARB2 gene. It takes vital parts in the physiological and pathological processes including the transportation of beta-glucocerebrosidase to the lysosome, infection of EV71 and load-induced cardiac myocyte hypertrophy. This article has reviewed the molecular structure and functions of SCARB2 gene and its protein, as well as their relationship with diseases.
Hand, Foot and Mouth Disease ; genetics ; Humans ; Lysosome-Associated Membrane Glycoproteins ; chemistry ; genetics ; physiology ; Myoclonic Epilepsies, Progressive ; genetics ; Parkinson Disease ; genetics ; Receptors, Scavenger ; chemistry ; genetics ; physiology

OBJECTIVETo investigate genetics and clinical characteristics of dentatorubral-pallidoluysian atrophy (DRPLA) in Chinese kindreds.

METHODSFragment analysis with laser-induced fluorescence in capillary electrophoresis was performed for the cytosine-adenine-guanine (CAG) repeats of DRPLA gene in 708 probands of autosomal dominant ataxia pedigrees and 119 sporadic ataxia cases.

RESULTSExpanded CAG repeats of DRPLA gene were detected in probands of three ataxia pedigrees, with the numbers of repeats being 16/58, 16/58 and 14/54, respectively. In addition to ataxia, patients with adult-onset disease also exhibited spasm and neck torsion.

CONCLUSIONOnly three cases of DRPLA have been identified among 827 cases, which suggested that DRPLA is a relatively rare subtype of SCA in Chinese population. Clinical variation among the patients suggested DRPLA has a wide spectrum of phenotype.

Adolescent ; Adult ; Aged ; Asian Continental Ancestry Group ; Brain ; pathology ; Child ; Child, Preschool ; China ; Female ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Mutation ; Myoclonic Epilepsies, Progressive ; diagnosis ; genetics ; Nerve Tissue Proteins ; genetics ; Pedigree ; Phenotype ; Trinucleotide Repeats ; Young Adult

OBJECTIVETo assist the establishment of platform and provide the reference standard for mutation detection in spinocerebellar ataxia (SCA) subtypes 1, 2, 3, 6, 7, 8, 10, 12, 17 and dentatorubral-pallidoluysian atrophy (DRPLA) in Chinese Han population.

METHODSThe nucleotide repeat numbers of the 9 SCA subtypes and DRPLA were detected using fluorescence-PCR and capillary gel electrophoresis technique in 300 healthy Chinese Han individuals.

RESULTSAmong the 300 healthy controls, the range of the CAG trinucleotide repeat number was 17 to 35 in SCA1, 14-28 in SCA2, 13-41 in SCA3/MJD, 4-16 in SCA6, 5-17 in SCA7, 5-21 in SCA12, 23-41 in SCA17, and 12-33 in DRPLA; and the range of CTA/CTG trinucleotide repeat number on SCA8 locus was 12-43 and the range of ATTCT pentanucleotide repeat number on SCA10 locus was 9-32. Of which, the 12 CTA/CTG repeats of SCA8, 9 ATTCT repeats of SCA10, 23 CAG repeats of SCA17 were the shortest normal repeat number, while the 41 CAG repeats of SCA3/MJD, 32 CAG repeats of SCA10 were the largest normal number that have not been reported.

CONCLUSIONThe normal ranges of polynucleotide repeats of different subtypes of SCA vary with geographical areas and ethnicities. It might be associated with the genetic and ethnic backgrounds. This is the first normal reference standard of polynucleotide repeat number of these ten SCA subtypes in Chinese Han.

Adult ; Asian Continental Ancestry Group ; ethnology ; genetics ; Base Sequence ; Case-Control Studies ; Humans ; Male ; Middle Aged ; Molecular Sequence Data ; Myoclonic Epilepsies, Progressive ; ethnology ; genetics ; Spinocerebellar Ataxias ; ethnology ; genetics ; Trinucleotide Repeat Expansion