Yandong Wang

Bio: Yandong Wang is an academic researcher from Sun Yat-sen University. The author has contributed to research in topics: Mutation (genetic algorithm) & Protein aggregation. The author has an hindex of 4, co-authored 4 publications receiving 469 citations.

Lanosterol reverses protein aggregation in cataracts

Abstract: The human lens is comprised largely of crystallin proteins assembled into a highly ordered, interactive macro-structure essential for lens transparency and refractive index. Any disruption of intra- or inter-protein interactions will alter this delicate structure, exposing hydrophobic surfaces, with consequent protein aggregation and cataract formation. Cataracts are the most common cause of blindness worldwide, affecting tens of millions of people1, and currently the only treatment is surgical removal of cataractous lenses. The precise mechanisms by which lens proteins both prevent aggregation and maintain lens transparency are largely unknown. Lanosterol is an amphipathic molecule enriched in the lens. It is synthesized by lanosterol synthase (LSS) in a key cyclization reaction of a cholesterol synthesis pathway. Here we identify two distinct homozygous LSS missense mutations (W581R and G588S) in two families with extensive congenital cataracts. Both of these mutations affect highly conserved amino acid residues and impair key catalytic functions of LSS. Engineered expression of wild-type, but not mutant, LSS prevents intracellular protein aggregation of various cataract-causing mutant crystallins. Treatment by lanosterol, but not cholesterol, significantly decreased preformed protein aggregates both in vitro and in cell-transfection experiments. We further show that lanosterol treatment could reduce cataract severity and increase transparency in dissected rabbit cataractous lenses in vitro and cataract severity in vivo in dogs. Our study identifies lanosterol as a key molecule in the prevention of lens protein aggregation and points to a novel strategy for cataract prevention and treatment.

Caspase-8 promotes NLRP1/NLRP3 inflammasome activation and IL-1β production in acute glaucoma

Abstract: Acute glaucoma is a sight-threatening condition characterized by a sudden and substantial rise in intraocular pressure (IOP) and consequent retinal ganglion cell (RGC) death. Angle closure glaucoma, a common cause of glaucoma in Asia that affects tens of millions of people worldwide, often presents acutely with loss of vision, pain, and high IOP. Even when medical and surgical treatment is available, acute angle closure glaucoma can cause permanent and irreversible loss of vision. Toll-like receptor 4 (TLR4) signaling has been previously implicated in the pathogenesis of IOP-induced RGC death, although the underlying mechanisms are largely unknown. In the present study, we used an acute IOP elevation/glaucoma model to investigate the underlying mechanism of RGC death. We found that TLR4 leads to increased caspase-8 expression; this elevation increases IL-1β expression and RGC death via a caspase-1–dependent pathway involving Nod-like receptor family, pyrin domain containing 1 (NLRP1)/NLRP3 inflammasomes and a caspase-1–independent pathway. We show that inhibition of caspase-8 activation significantly attenuates RGC death by down-regulating the activation of NLRP1 and NLRP3, thus demonstrating the pivotal role of caspase-8 in the TLR4-mediated activation of inflammasomes. These findings demonstrate collectively a critical role of caspase-8 in transducing TLR4-mediated IL-1β production and RGC death and highlight signal transduction in a caspase-1–dependent NLRP1/NLRP3 inflammasome pathway and a caspase-1–independent pathway in acute glaucoma. These results provide new insight into the pathogenesis of glaucoma and point to a treatment strategy.

A missense mutation in HK1 leads to autosomal dominant retinitis pigmentosa.

Abstract: PURPOSE Retinitis pigmentosa (RP) is a genetically heterogeneous disease with over 60 causative genes known to date. Nevertheless, approximately 40% of RP cases remain genetically unsolved, suggesting that many novel disease-causing genes are yet to be identified. In this study, we aimed to identify the causative mutation for a large autosomal dominant RP (adRP) family with negative results from known retinal disease gene screening. METHODS Linkage analysis followed by whole-exome sequencing was performed. Stringent variant filtering and prioritization was carried out to identify the causative mutation. RESULTS Linkage analysis identified a minimal disease region of 8 Mb on chromosome 10 with a peak parametric logarithm (base 10) of odds (LOD) score of 3.500. Further whole-exome sequencing identified a heterozygous missense mutation (NM_000188.2:c.2539G>A, p.E847K) in hexokinase 1 (HK1) that segregated with the disease phenotype in the family. Biochemical assays showed that the E847K mutation does not affect hexokinase enzymatic activity or the protein stability, suggesting that the mutation may impact other uncharacterized function or result in a gain of function of HK1. CONCLUSIONS Here, we identified HK1 as a novel causative gene for adRP. This is the first report that associates the glucose metabolic pathway with human retinal degenerative disease, suggesting a potential new disease mechanism.

Corrigendum: Lanosterol reverses protein aggregation in cataracts

Abstract: Nature 523, 607–611 (2015); doi:10.1038/nature14650 In this Letter, author Yong-Bin Yan was incorrectly associated with affiliation number 5 (Department of Ophthalmology, Xijing Hospital) instead of affiliation number 4 (State Key Laboratory of Membrane Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China).

Cytokines in Inflammatory Disease.

Abstract: This review aims to briefly discuss a short list of a broad variety of inflammatory cytokines. Numerous studies have implicated that inflammatory cytokines exert important effects with regard to various inflammatory diseases, yet the reports on their specific roles are not always consistent. They can be used as biomarkers to indicate or monitor disease or its progress, and also may serve as clinically applicable parameters for therapies. Yet, their precise role is not always clearly defined. Thus, in this review, we focus on the existing literature dealing with the biology of cytokines interleukin (IL)-6, IL-1, IL-33, tumor necrosis factor-alpha (TNF-α), IL-10, and IL-8. We will briefly focus on the correlations and role of these inflammatory mediators in the genesis of inflammatory impacts (e.g., shock, trauma, immune dysregulation, osteoporosis, and/or critical illness).

An artificial intelligence platform for the multihospital collaborative management of congenital cataracts

Abstract: Using artificial intelligence (AI) to prevent and treat diseases is an ultimate goal in computational medicine. Although AI has been developed for screening and assisted decision-making in disease prevention and management, it has not yet been validated for systematic application in the clinic. In the context of rare diseases, the main strategy has been to build specialized care centres; however, these centres are scattered and their coverage is insufficient, which leaves a large proportion of rare-disease patients with inadequate care. Here, we show that an AI agent using deep learning, and involving convolutional neural networks for diagnostics, risk stratification and treatment suggestions, accurately diagnoses and provides treatment decisions for congenital cataracts in an in silico test, in a website-based study, in a ‘finding a needle in a haystack’ test and in a multihospital clinical trial. We also show that the AI agent and individual ophthalmologists perform equally well. Moreover, we have integrated the AI agent with a cloud-based platform for multihospital collaboration, designed to improve disease management for the benefit of patients with rare diseases. An artificial intelligence agent integrated with a cloud-based platform for multihospital collaboration performs equally as well as ophthalmologists in the diagnosis of congenital cataracts in a series of online tests and a multihospital clinical trial.

A critical appraisal of the pathogenic protein spread hypothesis of neurodegeneration

Abstract: There has been an explosion in the number of papers discussing the hypothesis of 'pathogenic spread' in neurodegenerative disease - the idea that abnormal forms of disease-associated proteins, such as tau or α-synuclein, physically move from neuron to neuron to induce disease progression. However, whether inter-neuronal spread of protein aggregates actually occurs in humans and, if so, whether it causes symptom onset remain uncertain. Even if pathogenic spread is proven in humans, it is unclear how much this would alter the specific therapeutic approaches that are in development. A critical appraisal of this increasingly popular hypothesis thus seems both important and timely.

Pharmacological chaperone for α-crystallin partially restores transparency in cataract models

Abstract: Cataracts reduce vision in 50% of individuals over 70 years of age and are a common form of blindness worldwide. Cataracts are caused when damage to the major lens crystallin proteins causes their misfolding and aggregation into insoluble amyloids. Using a thermal stability assay, we identified a class of molecules that bind α-crystallins (cryAA and cryAB) and reversed their aggregation in vitro. The most promising compound improved lens transparency in the R49C cryAA and R120G cryAB mouse models of hereditary cataract. It also partially restored protein solubility in the lenses of aged mice in vivo and in human lenses ex vivo. These findings suggest an approach to treating cataracts by stabilizing α-crystallins.