Divergent CNS–Peripheral Signaling Reflects Astrocyte Dysfunction and Contributes to Insulin Resistance in Early Aβ Pathology
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1314074 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Alzheimer’s disease (AD) and type 2 diabetes mellitus (T2DM) are age-related disorders with similar pathological features, particularly insulin resistance and chronic inflammation. However, the primary drivers of insulin resistance in the AD brain remain debated. Although astrocytes and their metabolic functions have been increasingly implicated in AD, their specific role in brain insulin resistance is still unclear. In this study, we excluded peripheral metabolic confounders and focused on the alterations during a narrow time window surrounding amyloid-β (Aβ) plaque deposition in J20 mice. As Aβ pathology progressed, we observed a reduction in astrocyte numbers with increased morphological complexity. Furthermore, transcriptomic profiling demonstrated altered gene expression in synaptic, glial, and metabolic levels, along with a general suppression of insulin signaling pathways that indicated insulin resistance. Notably, we found a significant downregulation of serum and glucocorticoid-inducible kinase 1 (SGK1) and upregulation of insulin receptor substrate 2 (IRS2) expression, which diverged from the classic pattern observed in peripheral insulin resistance. We also detected a contradictory cytokine pattern in T-helper 17, where interleukin (IL)-6 and IL-17 levels were decreased in the hippocampus but elevated in the serum. This opposing trajectory suggest that astrocyte dysfunction and SGK1 downregulation have a critical role in immune signaling imbalance. Taken together, these findings highlight astrocyte depletion and/or dysfunction as key drivers of brain-specific insulin resistance and immune dysregulation in early AD, and that metabolic impairments in AD has a central nervous system-specific nature distinct from that in T2DM.
2025-09-10 | GSE306976 | GEO
Project description:The innate immune system can develop a form of memory called priming, where prior exposure to a stimulus enhances subsequent responses. While well-characterized in peripheral immunity, its function in brain-resident cells such as astrocytes under non-disease conditions remains unclear. Here we show that human astrocytes derived from the induced pluripotent stem cells of healthy female donors, but not microglia, acquire a primed state following transient immune stimulations. Upon subsequent exposure to amyloid-β (Aβ), these astrocytes secrete elevated levels of cytokines and promote microglial Aβ uptake. In contrast, astrocytes carrying the Alzheimer’s disease (AD) risk allele APOE4 exhibit reduced priming and fail to support microglial phagocytosis. These findings are validated in astrocyte-microglial co-cultures, cerebral organoids, and male mice, where astrocyte priming enhances Aβ clearance in an APOE4-sensitive manner. Our findings identify astrocytic immune memory as a modulator of microglial function and Aβ pathology, providing insights into how early protective responses in AD may be disrupted by genetic risk factors.
2025-07-06 | GSE274869 | GEO
Project description:The innate immune system can develop a form of memory called priming, where prior exposure to a stimulus enhances subsequent responses. While well-characterized in peripheral immunity, its function in brain-resident cells such as astrocytes under non-disease conditions remains unclear. Here we show that human astrocytes derived from the induced pluripotent stem cells of healthy female donors, but not microglia, acquire a primed state following transient immune stimulations. Upon subsequent exposure to amyloid-β (Aβ), these astrocytes secrete elevated levels of cytokines and promote microglial Aβ uptake. In contrast, astrocytes carrying the Alzheimer’s disease (AD) risk allele APOE4 exhibit reduced priming and fail to support microglial phagocytosis. These findings are validated in astrocyte-microglial co-cultures, cerebral organoids, and male mice, where astrocyte priming enhances Aβ clearance in an APOE4-sensitive manner. Our findings identify astrocytic immune memory as a modulator of microglial function and Aβ pathology, providing insights into how early protective responses in AD may be disrupted by genetic risk factors.
2025-07-06 | GSE274868 | GEO
Project description:The innate immune system can develop a form of memory called priming, where prior exposure to a stimulus enhances subsequent responses. While well-characterized in peripheral immunity, its function in brain-resident cells such as astrocytes under non-disease conditions remains unclear. Here we show that human astrocytes derived from the induced pluripotent stem cells of healthy female donors, but not microglia, acquire a primed state following transient immune stimulations. Upon subsequent exposure to amyloid-β (Aβ), these astrocytes secrete elevated levels of cytokines and promote microglial Aβ uptake. In contrast, astrocytes carrying the Alzheimer’s disease (AD) risk allele APOE4 exhibit reduced priming and fail to support microglial phagocytosis. These findings are validated in astrocyte-microglial co-cultures, cerebral organoids, and male mice, where astrocyte priming enhances Aβ clearance in an APOE4-sensitive manner. Our findings identify astrocytic immune memory as a modulator of microglial function and Aβ pathology, providing insights into how early protective responses in AD may be disrupted by genetic risk factors.
2025-07-06 | GSE274870 | GEO
Project description:Astrocyte-produced HB-EGF limits autoimmune CNS pathology
| PRJNA1028105 | ENA
Project description:Astrocyte-produced HB-EGF limits autoimmune CNS pathology [WGBS]
| PRJNA1028108 | ENA
Project description:Disease-associated astrocyte epigenetic memory promotes CNS pathology
2025-03-14 | GSE261763 | GEO
Project description:Extracellular matrix (ECM) remodeling is strongly linked to Alzheimer’s disease (AD) risk, but its functions are not fully understood. Here, we found that medial prefrontal cortex (mPFC) injection with chondroitinase ABC (ChABC) to remodel ECM reverses short-term memory loss and reduces Aβ deposition in 5xFAD mice. ECM remodeling also reactivates astrocytes, untangles aggrecan’s entanglement with amyloid-beta (Aβ) plaques, and encourages astrocyte recruitment to the surrounding plaques. ECM remodeling promotes astrocyte phagocytosis of Aβ plaque by activating the astrocyte phagocytosis receptor mertk and astrocytic vesicle circulation. Importantly, ECM remodeling enhances the autophagy-lysosome pathway in astrocytes to mediate Aβ clearance and alleviate AD pathology. Our work thus discovers a cellular mechanism to remodel the ECM to active astrocyte autophagic lysosomal pathway alleviation AD pathology. It may represent a potential therapeutic strategy and serve as a hallmark for treating AD.
2024-10-17 | PXD046784 | Pride
Project description:Microgliosis and astrogliosis characteristically occur at Aβ plaques in the brains of Alzheimer’s disease (AD) patients although the impact of gliosis in AD is poorly understood. We studied the impact of Aβ-induced gliosis using human induced pluripotent stem cell (hiPSC)-derived 3D neurospheres (hiNS), containing only astrocytes and neurons versus hiNS with the addition of iPSC-derived microglia (hiMG). Applying Aβ to hiNS containing only astrocytes and neurons triggered pathological features of AD including plaque-like aggregates, reactive astrocytes, oxidative stress, neuronal dysfunction and cell death. In contrast, when hiMG were combined with hiNS, infiltrating hiMG effectively phagocytose Aβ and facilitate neuroprotection. Our findings further support a pivotal role for microglia in modulating astrocyte Aβ responses by inducing AD-associated gene expression in astrocytes, including the upregulation of APOE, crucial for Aβ clearance. This model, highlighting the neuroprotective potential of microglia-astrocyte interactions, offers a novel platform for exploring AD mechanisms and novel therapeutic strategies.
2025-04-30 | GSE272186 | GEO
Project description:Astrocyte-produced HB-EGF limits autoimmune CNS pathology [RNA-Seq]
| PRJNA936611 | ENA