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Biology subjects

Palecek, S.

Publications and source records attributed to Palecek, S..

4 recordsLinked to original sources

Multi-omic analysis reveals maturation programs in human pluripotent stem cell-derived cardiomyocytes during long-term culture

Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) hold tremendous promise for disease modeling, drug discovery, and cardiac regenerative therapies. However, the immature phenotype of hPSC-CMs remains a major barrier limiting their translational utility. Here, we performed integrated multi-omic profiling to identify molecular pathways and regulatory programs associated with hPSC-CM maturation during long-term culture. hPSC-CMs were cultured for 113 days and analyzed using metabolomics, proteomics, and transcriptomics across progressive stages of maturation. Long-term culture induced widespread multi-omic remodeling, including significant changes in 142/934 metabolites, 550/3,556 proteins, and 2,892/23,309 transcripts from Day 30 to Day 113. Metabolomic analyses revealed early increases in phospholipid biosynthesis and mitochondrial beta oxidation of fatty acids from Day 30 to Day 60, suggesting metabolic priming precedes later maturation events. In contrast, proteomic remodeling was more prominent during later stages of maturation and was characterized by enhanced calcium handling and cell cycle exit. Transcriptomic analyses demonstrated progressive increases in ion channel expression, t-tubule organization, fatty acid metabolism, creatine shuttle pathways, and cell cycle arrest programs. Transcriptomic and integrative multi-omic pathway analyses identified coordinated suppression of TGF{beta}, MAPK, Wnt, and Hedgehog signaling together with activation of integrin-related, respiratory electron transport, muscle contraction, and Slit-Robo signaling pathways during maturation. Moreover, multi-omic transcription factor activity analysis prioritized a GATA4-centered network of putative cardiomyocyte maturation regulators including SOX7, SOX18, TBX2, and ZFPM2 (FOG2). Together, these findings elucidate the degree and pace of hPSC-CM maturation during long-term culture and establish an integrated multi-omic framework for identifying strategies to accelerate hPSC-CM maturation.

Cell Biology↗

A Multi-omics Strategy Enabled by Sequential Metabolomics and Proteomics for Human Pluripotent Stem Cell-derived Cardiomyocytes

Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) show immense promise for patient-specific disease modeling, cardiotoxicity screening, and regenerative therapy development. However, hPSC-CMs in culture have not recapitulated the structural or functional properties of adult CMs in vivo thus far. To gain global insight into hPSC-CM biology, we established a multi-omics method for analyzing the hPSC-CM metabolome and proteome from the same cell culture, creating multi-dimensional profiles of hPSC-CMs. Specifically, we developed a sequential extraction to capture metabolites and proteins from the same hPSC-CM monolayer cultures, and analyzed these extracts using high-resolution mass spectrometry (MS). Using this method, we annotated 205 metabolites/lipids and 4,008 proteins from 106 cells with high reproducibility. We further integrated the proteome and metabolome measurements to create network profiles of molecular phenotypes for hPSC-CMs. Out of 310 pathways identified using metabolomics and proteomics, 40 pathways were considered significantly overrepresented (FDR-corrected p [≤] 0.05). Highly populated pathways included those involved in protein synthesis (ribosome, spliceosome), ATP generation (oxidative phosphorylation), and cardiac muscle contraction. This multi-omics method achieves deep coverage of metabolites and proteins, creating a multidimensional view of the hPSC-CM phenotype, which provides a strong technological foundation to advance the understanding of hPSC-CM biology.

systems biology↗

A Human 3D neural assembloid model for SARS-CoV-2 infection

Clinical evidence suggests the central nervous system (CNS) is frequently impacted by SARS-CoV-2 infection, either directly or indirectly, although mechanisms remain unclear. Pericytes are perivascular cells within the brain that are proposed as SARS-CoV-2 infection points1. Here we show that pericyte-like cells (PLCs), when integrated into a cortical organoid, are capable of infection with authentic SARS-CoV-2. Prior to infection, PLCs elicited astrocytic maturation and production of basement membrane components, features attributed to pericyte functions in vivo. While traditional cortical organoids showed little evidence of infection, PLCs within cortical organoids served as viral replication hubs, with virus spreading to astrocytes and mediating inflammatory type I interferon transcriptional responses. Therefore, PLC-containing cortical organoids (PCCOs) represent a new assembloid model2 that supports SARS-CoV-2 entry and replication in neural tissue, and PCCOs serve as an experimental model for neural infection.

microbiology↗

14-helical β-peptides Elicit Toxicity against C. albicans by Forming Pores in the Cell Membrane and Subsequently Disrupting Intracellular Organelles

Synthetic peptidomimetics of antimicrobial peptides are promising as antimicrobial drug candidates because they promote membrane disruption and exhibit greater structural and proteolytic stability. We previously reported selective antifungal 14-helical {beta}-peptides, but the mechanism of antifungal toxicity of {beta}-peptides remains unknown. To provide insight into the mechanism, we studied antifungal {beta}-peptide binding to artificial membranes and living Candida albicans cells. We investigated the ability of {beta}-peptides to interact with and permeate small unilamellar vesicle models of fungal and bacterial membranes. The partition coefficient supported a pore-mediated mechanism characterized by the existence of a critical {beta}-peptide concentration separating low and high partition coefficient regimes. Live cell intracellular tracking of {beta}-peptides showed that {beta}-peptides translocated into the cytoplasm, and then disrupted the nucleus and vacuole sequentially, leading to cell death. This understanding of the mechanisms of antifungal activity will facilitate design and development of peptidomimetic AMPs, including 14-helical {beta}-peptides, for antifungal applications.\n\nGraphical Abstract\n\nO_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=46 SRC=\"FIGDIR/small/430850_ufig1.gif\" ALT=\"Figure 1\">\nView larger version (14K):\norg.highwire.dtl.DTLVardef@10ee335org.highwire.dtl.DTLVardef@66da40org.highwire.dtl.DTLVardef@82d132org.highwire.dtl.DTLVardef@7429e1_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗