Biology subjects

Hagman, S.

Publications and source records attributed to Hagman, S..

3 recordsLinked to original sources

bioRxiv2026

Hypoxia and Associated Acidosis Generate Cell-Type Specific Myeloid Responses in Glioblastoma

Hypoxia is a defining feature of glioblastoma (GBM), yet how it cooperates with hypoxia-associated acidosis to shape microglia and infiltrating monocyte-derived macrophages (MDM) remains poorly understood. We integrated cyclic immunohistochemistry, single-cell RNA sequencing, spatial transcriptomics, in vitro cell cultures, and DNA methylation profiling to outline hypoxia-driven responses in up to 136 GBMs. These hypoxic niches were selectively enriched for MDMs that activated carbonic anhydrase (CA) mediated pH buffering and other metabolic adaptation programs, enabling survival in acidic hypoxia, increasingly interacted with cancer cells, and show polarization toward immunosuppressive myeloid-derived suppressor cell (MDSC)-like states. In contrast, microglia were depleted in hypoxic areas, lacked compensatory CA isoenzymes, and developed TNF-linked stress responses and loss of homeostatic identity in acidic hypoxia. These findings identify metabolic adaptation to hypoxia-associated microenvironmental stress as a key determinant of GBM immune architecture, driving myeloid cell fates, spatial TME reorganization and the emergence of immunosuppressive tumor ecosystems.

cancer biology↗

bioRxiv2025

Human iPSC-based coculture model reveals neuroinflammatory crosstalk between microglia and astrocytes

BackgroundMicroglia and astrocytes have been implicated as central mediators of neuroinflammatory processes in several neurodegenerative diseases. However, their intricate crosstalk and contributions to pathogenesis remain elusive, highlighting the need for innovative in vitro approaches for investigating glial interactions in neuroinflammation. The aim of this study was to develop advanced human-based glial coculture models to explore the inflammatory roles and interactions of microglia and astrocytes in vitro. MethodsWe utilized human induced pluripotent stem cell (iPSC)-derived microglia and astrocytes cultured both in conventional culture dishes and in a compartmentalized microfluidic chip coculture platform. This novel platform features separate compartments for both cell types, enabling the creation of fluidically isolated microenvironments with spontaneous migration of microglia toward astrocytes through interconnecting microtunnels. To induce inflammatory activation, glial cultures were stimulated with lipopolysaccharide (LPS), a combination of tumor necrosis factor- (TNF-) and interleukin-1{beta} (IL-1{beta}), or interferon-{gamma} (IFN-{gamma}) for 24 hours. The glial activation and crosstalk were analyzed with immunocytochemistry, the secretion of inflammatory factors from the culture media was measured, and microglial migration was quantified. ResultsMicroglia-astrocyte cocultures were successfully generated in both conventional cultures and the microfluidic chip platform. Inflammatory stimulation with LPS and TNF-/IL-1{beta} elicited cell type-specific responses in microglia and astrocytes, respectively. Notably, the levels of secreted inflammatory mediators were altered under coculture conditions, revealing significant glial crosstalk. Utilization of our microfluidic coculture platform facilitated the study of microglial migration and glial activation within distinct inflammatory microenvironments. Microglia migrated efficiently toward the astrocyte compartment, and the chemoattractant adenosine diphosphate (ADP) notably increased microglial migration within this platform. Furthermore, inflammatory stimulation of the microfluidic chip cocultures successfully recapitulated glial crosstalk, revealing unique responses. This crosstalk was associated with elevated levels of complement component C3 in the cocultures, emphasizing the intricate interplay between microglia and astrocytes under inflammatory conditions. ConclusionsOur results depict an elaborate molecular crosstalk between inflammatory microglia and astrocytes, providing evidence of how glial cells orchestrate responses during neuroinflammation. Importantly, we demonstrate that the microfluidic coculture platform developed in this study for microglia and astrocytes provides a more functional and enhanced setup for investigating inflammatory glial interactions in vitro.

neuroscience↗

bioRxiv2024

Microglia from patients with multiple sclerosis display a cell-autonomous immune activation state

Aberrant and sustained activation of microglia is implicated in the progression and severity of multiple sclerosis (MS). However, whether intrinsic alterations in microglial function impact the pathogenesis of this disease remains unclear. We conducted transcriptomic and functional analyses of microglia-like cells (iMGLs) differentiated from induced pluripotent stem cells (iPSCs) from patients with MS (pwMS) to answer this question. We generated iPSCs from six pwMS showing increased microglial activity via translocator protein (TSPO)-PET imaging. We demonstrated that the differentiated iMGL transcriptional profile resembled the microglial signature found in MS lesions. Importantly, compared with healthy controls, MS iMGLs presented cell-autonomous differences in their regulation of inflammation, both in the basal state and following inflammatory lipopolysaccharide challenge. Through transcriptomic profiling, we showed that MS iMGLs display increased expression of genes known to be upregulated in MS microglia. Furthermore, upregulated genes in MS iMGLs were associated with immune receptor activation, antigen presentation, and the complement system, with known MS implications. Finally, functional analyses indicated that the transcriptional changes in MS iMGLs corresponded with alterations in the secretion of inflammatory cytokines and chemokines and increased phagocytosis. Together, our results provide evidence of putative cell-autonomous microglial activation in pwMS and identify transcriptomic and functional changes that recapitulate the phenotypes observed in vivo in microglia from pwMS. These findings indicate that MS disease-specific iPSCs are valuable tools for studying disease-specific microglial activation in vitro and highlight microglia as potential therapeutic targets in MS.

neuroscience↗