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Biology subjects

Ng, T. F.

Publications and source records attributed to Ng, T. F..

3 recordsLinked to original sources

Clusterin reverses epitheliopathy, reduces inflammation, and restores goblet cells and corneal nerves in a mouse model of autoimmune dry eye

Chronic ocular surface disease (OSD) is characterized by corneal epitheliopathy, reduced barrier function and loss of nerves, accompanied by persistent inflammation. Current treatments offer limited relief and there is no approved therapy that promotes neurosensory regeneration in OSD. Here, we tested the therapeutic efficacy of clusterin (CLU), a molecular chaperone and MMP9 inhibitor found in tears, in Thbs1-deficient mice, a preclinical model of autoimmune dry eye associated with Sjogrens disease (SjD). These mice were treated topically at the ocular surface, bilaterally, for 3 weeks with recombinant human CLU (rhCLU) or human plasma-derived CLU (pCLU) eyedrops and compared to standard-of-care 0.1% dexamethasone eyedrops. Treatment with CLU significantly improved corneal barrier integrity, increased corneal nerve density, enhanced the proportion of corneal nerves with immunoreactivity for CGRP and promoted conjunctival goblet cell regeneration. Furthermore, CLU reduced immunoreactivity for ADAM17 in the corneal epithelium and reduced Tnfa expression in the conjunctiva, supporting its anti-inflammatory effect. Notably, all these effects were comparable to, or even exceeded, those resulting from treatment with dexamethasone. Based on its efficacy, we introduce CLU as a multifunctional and promising biotherapeutic for a widespread range of ocular inflammatory conditions involving corneal epitheliopathy and nerve loss, including dry eye associated with SjD.

immunology↗

CIP2A is a prime synthetic-lethal target for BRCA-mutated cancers

BRCA1/2-mutated cancer cells must adapt to the genome instability caused by their deficiency in homologous recombination. Identifying and targeting these adaptive mechanisms may provide new therapeutic strategies. Here we present the results of genome-scale CRISPR/Cas9-based synthetic lethality screens in isogenic pairs of BRCA1- and BRCA2-deficient cells that identified the gene encoding CIP2A as essential in a wide range of BRCA1- and BRCA2-mutated cells. Unlike PARP inhibition, CIP2A-deficiency does not cause accumulation of replication-associated DNA lesions that require homologous recombination for their repair. CIP2A is cytoplasmic in interphase but, in mitosis, accumulates at DNA lesions as part of a complex with TOPBP1, a multifunctional genome stability factor. In BRCA-deficient cells, the CIP2A-TOPBP1 complex prevents lethal mis-segregation of acentric chromosomes that arises from impaired DNA synthesis. Finally, physical disruption of the CIP2A-TOPBP1 complex is highly deleterious in BRCA-deficient cells and tumors, indicating that targeting this mitotic chromosome stability process represents an attractive synthetic-lethal therapeutic strategy for BRCA1- and BRCA2-mutated cancers.

cancer biology↗

Identification of \"Missing Link\" Families of Small DNA Tumor Viruses

Polintons (also known as Mavericks) were initially identified as a widespread class of eukaryotic transposons named for their hallmark type B DNA polymerase and retrovirus-like integrase genes. It has since been recognized that many polintons encode possible capsid proteins and viral genome-packaging ATPases similar to those of a diverse range of double-stranded DNA (dsDNA) viruses. This supports the inference that at least some polintons are viruses that remain capable of cell-to-cell spread. At present, there are no polinton-associated capsid protein genes annotated in public sequence databases. To rectify this deficiency, we used a data-mining approach to investigate the distribution and gene content of polinton-like elements and related DNA viruses in animal genomic and metagenomic sequence datasets. The results define a discrete family-like clade of animal-specific viruses with two genus-level divisions. We suggest the family name Adintoviridae, connoting similarities to adenovirus virion proteins and the presence of a retrovirus-like integrase gene. Although adintovirus-class PolB sequences were detected in datasets for fungi and various unicellular eukaryotes, sequences resembling adintovirus virion proteins and accessory genes appear to be restricted to animals. Degraded adintovirus sequences are endogenized into the germlines of a wide range of animals, including humans.

microbiology↗