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Wolnik, J.

Publications and source records attributed to Wolnik, J..

2 recordsLinked to original sources
bioRxiv2026

Serotype-dependent bioenergetic and electrophysiological remodelling in iPSC-derived cardiomyocytes from rheumatoid arthritis patients

BackgroundPatients with rheumatoid arthritis (RA) exhibit increased cardiovascular morbidity and mortality that are not fully explained by traditional risk factors, with cardiovascular outcomes differing between seropositive (spRA) and seronegative (snRA) disease. The cellular mechanisms linking chronic inflammation to cardiac dysfunction remain poorly defined, and no patient-specific cardiomyocyte model has resolved cellular phenotypes by RA serotype. MethodsHuman induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) were generated from healthy donors and patients with spRA and snRA. Bioenergetic and electrophysiological responses to key RA proinflammatory cytokines (TNF-, IL-1{beta}, IL-6) and anti-rheumatic drugs (adalimumab, tofacitinib) were assessed using Seahorse assays, patch-clamp electrophysiology, multi-electrode array recordings and RT-qPCR. ResultssnRA cardiomyocytes exhibited impaired TNF--induced oxidative phosphorylation, accompanied by attenuated expression of ATP5B, LDHA and DLD. In contrast, spRA cardiomyocytes showed baseline electrophysiological alterations, including shortened APD90 and increased action-potential triangulation. TNF- depolarised the maximum diastolic potential in both RA serotypes. At the multicellular level, cytokine effects were serotype-specific: IL-1{beta} selectively prolonged QT interval in spRA monolayers (p < 0.001), whereas IL-6 prolonged QT in snRA (p < 0.05). Both RA serotypes showed impaired TNF--driven induction of KCNJ3 and KCNA5. Adalimumab selectively induced ATP5B in spRA but failed to engage either pathway in snRA, while tofacitinib selectively induced KCNJ3 in healthy but not RA cardiomyocytes. ConclusionsThese findings define distinct, serotype-specific pathways of cardiac remodelling in RA that converge on a shared proarrhythmic phenotype, provide a cellular framework for cardiovascular risk in RA and identify candidate mechanisms relevant to therapy-associated cardiovascular safety. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=94 SRC="FIGDIR/small/727798v1_ufig1.gif" ALT="Figure 1"> View larger version (38K): org.highwire.dtl.DTLVardef@ceb808org.highwire.dtl.DTLVardef@1942a26org.highwire.dtl.DTLVardef@5b32eforg.highwire.dtl.DTLVardef@16cf774_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗
bioRxiv2024

Effect of heme oxygenase-1 on the expression of interferon-stimulated genes

Heme oxygenase-1 (HO1, Hmox1) degrades excess heme and is considered an anti-oxidative and anti-inflammatory enzyme. Our previous studies in Hmox1 knockout mice revealed induction of interferon-stimulated genes (ISGs) in all cell types analyzed, despite unchanged interferon production. Here, we sought to identify the pathway underlying HO1-dependent ISG regulation and determine how ISG expression changes in cultured cells in response to stressors typical of Hmox1-deficient mice. Using murine wild-type and Hmox1-deficient (KO-Hmox1) fibroblasts, we showed that in cells cultured under control conditions, the expression of most of the tested ISGs was independent of cellular HO1 status. We then analyzed the effect of extrinsic stressors: hemolytic, oxidative, genotoxic, and replication stress, proinflammatory TNF, and endogenous heme overload. TNF (upregulated in Hmox1 knockout mice) was the sole and universal ISG inducer in both wild-type and KO-Hmox1 fibroblasts. Unexpectedly, the response of KO-Hmox1 cells to exogenous TNF was weakened, probably due to impaired NF-{kappa}B activity and reduced p65 nuclear retention. A similar decrease we observed for STAT1. Additionally, the presence of TREX1 exonuclease in the nucleus indicated impaired nuclear envelope integrity. Noteworthy, HO1 colocalizes with PARP1, a protein regulating cytoplasmic-nuclear transport. Olaparib-mediated PARP1 inhibition abolished TNA-induced nuclear accumulation of p65 and STAT1 in wild-type cells, but not in KO-Hmox1 counterparts. In summary, the inflammation typical of Hmox1-deficient mice appears to be a major inducer of ISGs in vivo. Despite this, the inflammatory response to exogenous TNF is attenuated in KO-Hmox1 cells, likely due to decreased nuclear retention of NF-{kappa}B and STAT1.

immunology↗