Biology subjects

Podlesny-Drabiniok, A.

Publications and source records attributed to Podlesny-Drabiniok, A..

3 recordsLinked to original sources

bioRxiv2026

A rapid, genetically-tractable human iPSC-derived model for studying tissue-resident macrophage biology in Alzheimer's and other diseases

Large-scale genetic and preclinical studies strongly implicate myeloid cells, particularly brain-resident macrophages, in the pathogenesis of Alzheimer's disease (AD). Efferocytic clearance of apoptotic cells and other cholesterol-rich cellular debris is a core macrophage function and represents an active area of AD research. However, human tissue-resident macrophages remain difficult to model in vitro as they acquire their transcriptional and functional identities in response to signals from their host tissue microenvironment. Many existing differentiation protocols mimic human brain macrophage developmental trajectories, but these protocols rely either on multi-step cytokine cocktails and lengthy differentiation or transduction of multiple transcription factors, both of which introduce variability and complicate genetic manipulation. To address these limitations, we developed a simplified protocol that generates high-purity (>90% CD45+CD11b+) human iPSC-derived macrophage-like cells (iMacs) from cryopreservable erythro-myeloid progenitor (EMP)-like intermediates in 19 days, including a final 7-day maturation step driven by macrophage colony-stimulating factor (M-CSF) alone. Transcriptomic profiling reveals that iMacs show enrichment for phagocytic and lysosomal programs, processes integral to efferocytosis. At both the transcriptional and protein level, iMacs have higher expression of scavenger receptors such as CD36, CD163 and MRC1, and of AD risk genes such as TREM2. Functionally, iMacs show enhanced phagocytic uptake of diverse substrates relative to iPSC-derived microglia, including carboxylated latex beads, zymosan, amyloid-{beta} 1-42, and amyloid-{beta} 1-40, and exhibit expanded lysosomal mass. Robust TREM2 expression and signaling make iMacs a sensitive platform for interrogating TREM2 biology, with markedly higher phosphorylation of SYK and PLC{gamma}2 in response to TREM2 engagement compared to iPSC-derived microglia. iMacs also tolerate lipid-mediated siRNA transfection with high survival and knockdown efficiency, enabling rapid genetic perturbation of AD risk genes. Together, these features make iMacs a practical, scalable, and genetically tractable human macrophage model for studying the regulation and cell biology of core macrophage functions that are known to play critical roles in AD, aging, and other disorders.

neuroscience↗

bioRxiv2024

Cytokine-induced reprogramming of human macrophages toward Alzheimer's disease-relevant molecular and cellular phenotypes in vitro

Myeloid cells including brain-resident (microglia) and peripheral macrophages play a crucial role in various pathological conditions, including neurodegenerative disorders like Alzheimers disease (AD). They respond to disruption of tissue homeostasis associated with disease conditions by acquiring various transcriptional and functional states. Experimental investigation of these states is hampered by the lack of tools that enable accessible and robust reprogramming of human macrophages toward Alzheimers disease-relevant molecular and cellular phenotypes in vitro. In this study, we investigated the ability of a cytokine mix, including interleukin-4 (IL4), colony stimulating factor 1 (CSF1/MCSF), interleukin 34 (IL34) and transforming growth factor beta (TGF{beta}), to induce reprogramming of cultured human THP-1 macrophages. Our results indicate this treatment led to significant transcriptomic changes, driving THP-1 macrophages towards a transcriptional state reminiscent of disease-associated microglia (DAM) and lipid-associated macrophages (LAM) collectively referred to as DLAM. Transcriptome profiling revealed gene expression changes related to oxidative phosphorylation, lysosome function, and lipid metabolism. Single-cell RNA sequencing revealed an increased proportion of DLAM clusters in cytokine mix-treated THP-1 macrophages. Functional assays demonstrated alterations in cell motility, phagocytosis, lysosomal activity, and metabolic and energetic profiles. Our findings provide insights into the cytokine-mediated reprogramming of macrophages towards disease-relevant states, highlighting their role in neurodegenerative diseases and potential for therapeutic development.

immunology↗

bioRxiv2023

BHLHE40/41 regulate macrophage/microglia responses associated with Alzheimer's disease and other disorders of lipid-rich tissues

BackgroundGenetic and experimental evidence strongly implicates myeloid cells in the etiology of AD and suggests that AD-associated alleles and genes may modulate disease risk by altering the transcriptional and cellular responses of macrophages (like microglia) to damage of lipid-rich tissues (like the brain). Specifically, recent single-cell/nucleus RNA sequencing (sc/nRNA-seq) studies identified a transcriptionally distinct state of subsets of macrophages in aging or degenerating brains (usually referred to as disease- associated microglia or DAM) and in other diseased lipid-rich tissues (e.g., obese adipose tissue, fatty liver, and atherosclerotic plaques). We collectively refer to these subpopulations as lipid-associated macrophages or LAMs. Importantly, this particular activation state is characterized by increased expression of genes involved in the phagocytic clearance of lipid-rich cellular debris (efferocytosis), including several AD risk genes. MethodsWe used sc/nRNA-seq data from human and mouse microglia from healthy and diseased brains and macrophages from other lipid-rich tissues to reconstruct gene regulatory networks and identify transcriptional regulators whose regulons are enriched for LAM response genes (LAM TFs) across species. We then used gene knock- down/knock-out strategies to validate some of these LAM TFs in human THP-1 macrophages and iPSC-derived microglia in vitro, as well as mouse microglia in vivo. ResultsWe nominate 11 strong candidate LAM TFs shared across human and mouse networks (BHLHE41, HIF1A, ID2, JUNB, MAF, MAFB, MEF2A, MEF2C, NACA, POU2F2 and SPI1). We also demonstrate a strong enrichment of AD risk alleles in the cistrome of BHLHE41 (and its close homolog BHLHE40), thus implicating its regulon in the modulation of disease susceptibility. Loss or reduction of BHLHE40/41 expression in human THP-1 macrophages and iPSC-derived microglia, as well as loss of Bhlhe40/41 in mouse microglia led to increased expression of LAM response genes, specifically those involved in cholesterol clearance and lysosomal processing, with a concomitant increase in cholesterol efflux and storage, as well as lysosomal mass and degradative capacity. ConclusionsTaken together, this study nominates transcriptional regulators of the LAM response, experimentally validates BHLHE40/41 in human and mouse macrophages/microglia, and provides novel targets for therapeutic modulation of macrophage/microglia function in AD and other disorders of lipid-rich tissues. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=95 SRC="FIGDIR/small/528372v1_ufig1.gif" ALT="Figure 1"> View larger version (22K): org.highwire.dtl.DTLVardef@10f356forg.highwire.dtl.DTLVardef@17d259forg.highwire.dtl.DTLVardef@1312809org.highwire.dtl.DTLVardef@3b6a8f_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗