Understanding organellar protein folding capacities and assessing their pharmacological modulation by small molecules

Identification of Natural Products as Potential Pharmacological Chaperones for Protein Misfolding Diseases

Defective protein folding and accumulation of misfolded proteins is associated with neurodegenerative, cardiovascular, secretory, and metabolic disorders. Efforts are being made to identify small-molecule modulators or structural-correctors for conformationally destabilized proteins implicated in various protein aggregation diseases. Using a metastable-reporter-based primary screen, we evaluated pharmacological chaperone activity of a diverse class of natural products. We found that a flavonoid glycoside (C-10, chrysoeriol-7-O-β-D-glucopyranoside) stabilizes metastable proteins, prevents its aggregation, and remodels the oligomers into protease-sensitive species. Data was corroborated with additional secondary screen with disease-specific pathogenic protein. In vitro and cell-based experiments showed that C-10 inhibits α-synuclein aggregation which is implicated in synucleinopathies-related neurodegeneration. C-10 interferes in its structural transition into β-sheeted fibrils and mitigates α-synuclein aggregation-associated cytotoxic effects. Computational modeling suggests that C-10 binds to unique sites in α-synuclein which may interfere in its aggregation amplification. These findings open an avenue for comprehensive SAR development for flavonoid glycosides as pharmacological chaperones for metastable and aggregation-prone proteins implicated in protein conformational diseases.

Gut microbiota changes in patients with autism spectrum disorders

Autism spectrum disorder (ASD) has a high incidence of intestinal comorbidity, indicating a strong association with gut microbiota. The purpose of this study was to characterize gut microbiota profiles in children with ASD. Seventy-seven children with ASD [33 with mild ASD and 44 with severe ASD according to the Childhood Autism Rating Scale score] and 50 age-matched healthy children were enrolled. Compared with children in the healthy control (HC) group, those in the ASD group showed higher biomass, richness, and biodiversity of gut microbiota, and an altered microbial community structure. At the genus level, there was a significant increase in the relative abundance of unidentified Lachnospiraceae, Clostridiales, Erysipelotrichaceae, Dorea, Collinsella, and Lachnoclostridium, whereas Bacteroides, Faecalibacterium, Parasutterella, and Paraprevotella were significantly lower in the ASD group than in the control group. The presence of unidentified Erysipelotrichaceae, Faecalibacterium, and Lachnospiraceae was positively correlated with ASD severity. Notably, three microbial markers (Faecalitalea, Caproiciproducens and Collinsella) were identified in a random forest model with an area under the curve (AUC) of 0.94 for differentiation between HCs and ASD patients. Furthermore, the validation model was consistent with the discovery set (AUC = 0.98, 95% CI: 97.9%-100%). The training and testing sets were more effective when the number of bacteria was increased. In addition, the functional properties (such as galactose metabolism, glycosyltransferase activity, and glutathione metabolism) displayed significant differences between the ASD and HC groups. The current study provides evidence for the relationship between gut microbiota and ASD, with the findings suggesting that gut microbiota could contribute to symptomology. Thus, modulation of gut microbiota may be a new therapeutic strategy for ASD.