Biology subjects

Naguib, S.

Publications and source records attributed to Naguib, S..

3 recordsLinked to original sources

bioRxiv2026

IOP-independent treatment for neurodegeneration in glaucoma using optimized ROS-scavenging microparticles for sustained release of erythropoietin

Glaucoma is a slow-progressing neurodegenerative disease of the optic projection to the brain and a leading cause of blindness worldwide. Current treatments are targeted towards lowering intraocular pressure (IOP), the only known, modifiable risk factor; however, this strategy is ineffective in many patients. An early hallmark of glaucomatous neurodegeneration is increased reactive oxygen species (ROS), representing an alternative opportunity for intervention to halt or slow disease progression. In this work, we optimize a ROS-scavenging copolymer, poly(propylene sulfide-co-ethylene sulfide) (PPSES), for formulation of size-controlled, stabilized, antioxidant microparticles (MPs) for sustained release of the protein erythropoietin (EPO). EPO promotes biological antioxidant defense via activation of NRF2-mediated transcription of antioxidant genes. This MP system overcomes the short half-life of EPO and leverages the combined benefits of bioactive EPO with long-lasting, inherently antioxidant PPSES MPs. The lead EPO-MP formulation preserves neurons in both mouse and non-human primate models of glaucoma through suppression of oxidative stress and optic nerve degeneration. EPO-loaded PPSES MPs represent a translationally relevant therapy for long-term management of glaucoma independent of IOP.

bioengineering↗

bioRxiv2026

Cortical astrocytes control stress resilience

BackgroundChronic stress exposure is a risk factor for several psychiatric disorders, including post-traumatic stress disorder (PTSD) and major depression (MDD), with the prefrontal cortex (PFC) playing a key role in mediating this stress susceptibility. However, most individuals who are exposed to chronic stress are resilient and do not develop psychopathology. Recent evidence suggests that glial cells, especially astrocytes, play an important role in controlling stress-induced anxiety- and depression-like behavior, yet their role in contributing to stress resilience is not understood. MethodsUsing fiber photometry, chemogenetics, and RNA-sequencing in male mice, we establish a role for PFC astrocytes in stress resilience. ResultsWe demonstrate that stress-induced increases in astrocytic calcium activity are both necessary and sufficient for resilience. Bioinformatic analysis reveals robust transcriptional responses in PFC astrocytes that differ between susceptible vs. resilient mice and are unique when compared to astrocytic transcriptional changes in other limbic regions. Comparison with human RNA-sequencing data indicates that molecular changes observed in PFC astrocytes from susceptible mice converge with gene expression changes observed in MDD patients. ConclusionsTogether, these data support targeting astrocytes as a potential therapy for negative behavioral consequences following stress exposure and reveal potential molecular mechanisms within PFC astrocytes that could contribute to depressive-like behaviors.

neuroscience↗

bioRxiv2026

Transplantation of Human IPSC-derived Microglia Ameliorates Neuropathology and Circuit Dysfunction in Progranulin-Deficient Mice

Frontotemporal dementia (FTD) is a major cause of early-onset neurodegeneration characterized by progressive behavioral, emotional, and cognitive decline. Progranulin haploinsufficiency, a leading genetic cause of familial FTD, disrupts lysosomal function, lipid metabolism, autophagy, and neuroimmune signaling across multiple cell types. Increasing evidence indicates that microglia are particularly sensitive to progranulin loss, exhibiting elevated complement activation that contributes to TDP-43 proteinopathy and neuronal dysfunction. Here, we investigate the biological role of restoring progranulin exclusively within microglia by transplanting human induced pluripotent stem cell-derived microglia (iMG) into progranulin (Grn)-deficient mice. We find that wild-type, but not Grn-deficient, human iMG restore brain-wide progranulin levels, normalize microglial transcriptional states, and ameliorate pathological, functional, and behavioral phenotypes associated with progranulin loss. Because microglia are the only source of progranulin in this system, these findings demonstrate that microglial progranulin is sufficient to restore key aspects of cellular, circuit, and behavioral homeostasis in a progranulin-deficient FTD model. More broadly, this work highlights a central, microglia-intrinsic role for progranulin in maintaining brain function and provides a framework for dissecting microglia-specific mechanisms across FTD and related neurodegenerative disorders. One Sentence SummaryOur study demonstrates that xenotransplantation of wild-type human iPSC-derived microglia into progranulin-deficient mice mitigates core neuropathological, network-level, and behavioral features of Frontotemporal Dementia.

neuroscience↗