Biology subjects

Shi, K.-X.

Publications and source records attributed to Shi, K.-X..

3 recordsLinked to original sources

bioRxiv2025

A Universal 6iL/E4 Culture System for Deriving and Maintaining Embryonic Stem Cells Across Mammalian Species

The derivation of authentic embryonic stem cells (ESCs) from diverse mammalian species offers valuable opportunities for advancing regenerative medicine, studying developmental biology, and enabling species conservation. Here, we report the development of a robust, serum-free culture system, termed 6iL/E4 that enables the derivation and long-term self-renewal of ESCs from multiple mammalian species, including mouse, rat, bovine, rabbit, and human. Using systematic signaling pathway analysis, we identified key regulators--including GSK3, STAT3, PDGFR, BRAF, and LATS--critical for ESC maintenance across species. Additionally, inducible expression of KLF2 and NANOG enhances the naive pluripotency and chimeric potential of bovine ESCs. The E4 medium also supports stable ESC growth while minimizing lineage bias. These findings reveal conserved principles underlying ESC self-renewal across divergent mammalian species and provide a universal platform for cross-species stem cell research, disease modeling, and biotechnology applications. In BriefWang et al. developed 6iL/E4, a serum-free system sustaining ESCs from mouse, rat, bovine, rabbit, and human. These findings reveal conserved fundamental mechanisms governing ESC self-renewal across diverse mammalian species. HighlightsO_LIDeveloped 6iL/E4 system for ESC derivation across five mammalian species. C_LIO_LIPDGFR signaling inhibition as critical for ESC derivation across species. C_LIO_LIE4 medium improves ESC maintenance and avoids neural bias of traditional N2B27. C_LIO_LIInducible KLF2/NANOG enhances naive pluripotency and chimera formation in bovine. C_LI

cell biology↗

bioRxiv2025

Selective GSK3α Inhibition Promotes Self-Renewal Across Different Stem Cell States

Pan-GSK3/{beta} inhibition promotes stem cell self-renewal through activation of WNT/{beta}-catenin signaling, but its broad effects complicate the precise control of stem cell states. Here, we show that selective inhibition of GSK3 with BRD0705 supports the long-term self-renewal of mouse embryonic stem cells (ESCs), epiblast stem cells (EpiSCs), and neural stem cells (NSCs), independent of {beta}-catenin signaling. When combined with the tankyrase inhibitor IWR1, BRD0705 broadly supports the maintenance of diverse pluripotent stem cell states, including ESCs, EpiSCs, and formative pluripotent stem cells. This BRD0705/IWR1 cocktail enables stable co-culture of naive ESCs and primed EpiSCs while preserving their distinct molecular and functional identities. Single-cell transcriptomics, epigenomic profiling, and functional assays confirm sustained lineage-specific features across stem cell types. These findings demonstrate that selective GSK3 inhibition enhances stemness by buffering against differentiation cues and promoting intrinsic self-renewal capacity. This work identifies GSK3 as a key regulator of self-renewal across distinct stem cell states and establishes a versatile culture system with broad applications. In BriefWang et al. demonstrate that selective GSK3 inhibition with BRD0705 supports self-renewal of pluripotent and neural stem cells. Combined with IWR1, it enables long-term co-culture of naive and primed stem cells while preserving their distinct molecular and functional identities. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=181 HEIGHT=200 SRC="FIGDIR/small/653860v1_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@4e371eorg.highwire.dtl.DTLVardef@104b287org.highwire.dtl.DTLVardef@164bd96org.highwire.dtl.DTLVardef@daf1ba_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIGSK3 inhibition by BRD0705 promotes self-renewal of ESCs, EpiSCs, and NSCs C_LIO_LIBRD0705/IWR1 enables long-term co-culture of ESCs and EpiSCs C_LIO_LICo-cultured ESCs and EpiSCs retain distinct naive or primed identities C_LIO_LIBRD0705 preserves stem cell states independently of {beta}-catenin signaling C_LI

cell biology↗

bioRxiv2024

APOE Christchurch enhances a disease-associated microglial response to plaque but suppresses response to tau pathology

BackgroundApolipoprotein E {varepsilon}4 (APOE4) is the strongest genetic risk factor for late-onset Alzheimers disease (LOAD). A recent case report identified a rare variant in APOE, APOE3-R136S (Christchurch), proposed to confer resistance to autosomal dominant Alzheimers Disease (AD). However, it remains unclear whether and how this variant exerts its protective effects. MethodsWe introduced the R136S variant into mouse Apoe (ApoeCh) and investigated its effect on the development of AD-related pathology using the 5xFAD model of amyloidosis and the PS19 model of tauopathy. We used immunohistochemical and biochemical analysis along with single-cell spatial transcriptomics and proteomics to explore the impact of the ApoeCh variant on AD pathological development and the brains response to plaques and tau. ResultsIn 5xFAD mice, ApoeCh enhances a Disease-Associated Microglia (DAM) phenotype in microglia surrounding plaques, and reduces plaque load, dystrophic neurites, and plasma neurofilament light chain. By contrast, in PS19 mice, ApoeCh suppresses the microglial and astrocytic responses to tau-laden neurons and does not reduce tau accumulation or phosphorylation, but partially rescues tau-induced synaptic and myelin loss. We compared how microglia responses differ between the two mouse models to elucidate the distinct DAM signatures induced by ApoeCh. We identified upregulation of antigen presentation-related genes in the DAM response in a PS19 compared to a 5xFAD background, suggesting a differential response to amyloid versus tau pathology that is modulated by the presence of ApoeCh. ConclusionsThese findings highlight the ability of the ApoeCh variant to modulate microglial responses based on the type of pathology, enhancing DAM reactivity in amyloid models and dampening neuroinflammation to promote protection in tau models. This suggests that the Christchurch variants protective effects likely involve multiple mechanisms, including changes in receptor binding and microglial programming.

neuroscience↗