Biology subjects

Zeldin, D. C.

Publications and source records attributed to Zeldin, D. C..

3 recordsLinked to original sources

bioRxiv2026

Astrocytic sEH-EET signaling regulates microglial lysosomal function and suppresses the STING-Type I interferon pathway in Alzheimer's disease

Background: The development of {beta}-amyloid (A{beta}) pathology in Alzheimer's disease (AD) is accompanied by profound changes in astrocytes and microglia and associated neuroinflammation. Soluble epoxide hydrolase (sEH), which degrades anti-inflammatory epoxyeicosatrienoic acids (EETs), is elevated in the AD brain, yet how EETs restrain inflammation remains poorly understood. Methods: We performed single-nucleus RNA sequencing (snRNA-seq) on brains from wild-type, sEH knockout, 5xFAD, and 5xFAD; sEH knockout mice, and used primary mouse microglia and human induced pluripotent stem cell (iPSC)-derived microglia to define the underlying mechanism. To test cell-type-specific contributions, we generated astrocyte- and endothelial-specific she knockout mice and crossed them with 5xFAD mice. Results: Genetic disruption of sEH in 5xFAD mice markedly reduced the abundance of a type I interferon (IFN)-responsive microglial subcluster and lowered phospho-STING (pSTING) levels. In primary microglia, supplementation with 11,12-EET attenuated STING activation and IFN target gene expression; blocking lysosomal acidification abolished this effect and caused pSTING to accumulate, identifying lysosomal degradation as a critical route for terminating STING signaling. 11,12-EET also enhanced microglial lysosomal acidification and A{beta} phagocytosis. Astrocytic, but not endothelial, disruption of sEH recapitulated the reductions in A{beta} pathology and microglial STING activation seen in global sEH-deficient mice, identifying astrocytes as the major cellular source of EETs regulating this pathway. Conclusion: We define an astrocyte-microglia axis in which astrocytic sEH limits EET availability and thereby sustains microglial STING signaling. By promoting lysosomal clearance of pSTING, EETs suppress type I IFN signaling and enhance microglial A{beta} clearance, highlighting sEH inhibition as a therapeutic strategy targeting both neuroinflammation and lysosomal dysfunction in AD.

neuroscience↗

bioRxiv2021

Proteome and functional decline as platelets age in the circulation

Anucleate platelets circulate in the blood of healthy individuals for approximately 7-10 days during which time their protein composition may change. We hypothesized such changes would be linked to altered structure and function. Here, we separated platelets of different ages based on mRNA content and characterised them using proteomics, immunofluorescence and functional assays. Total protein content was 45{+/-}5% (n=4) lower in old platelets compared to young platelets. Predictive proteomic pathway analysis identified associations with 28 biological processes, notably increased haemostasis in young platelets and apoptosis in old platelets. Further studies confirmed platelet ageing was linked to a reduction decrease in cytoskeletal proteins, a reduction in mitochondria number, and lower calcium dynamics and granule secretion. This work delineates physical and functional changes in platelets as they age and serves as a base to examine differences associated with altered mean age of platelet populations in conditions such as immune thrombocytopenia and diabetes.

cell biology↗

bioRxiv2021

Furin cleavage of the SARS-CoV-2 spike is modulated by O-glycosylation

The SARS-CoV-2 coronavirus responsible for the global pandemic contains a unique furin cleavage site in the spike protein (S) that increases viral infectivity and syncytia formation. Here, we show that O-glycosylation near the furin cleavage site is mediated by specific members of the GALNT enzyme family and is dependent on the novel proline at position 681 (P681). We further demonstrate that O-glycosylation of S decreases furin cleavage. Finally, we show that GALNT family members capable of glycosylating S are expressed in human respiratory cells that are targets for SARS-CoV-2 infection. Our results suggest that O-glycosylation may influence viral infectivity/tropism by modulating furin cleavage of S and provide mechanistic insight into the potential role of P681 mutations in the recently identified, highly transmissible B.1.1.7 variant.

biochemistry↗