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Park, M.

Publications and source records attributed to Park, M..

At least 37 records · Page 2Linked to original sources
bioRxiv2025

Multi-omics analysis of TNBC organoids identifies phosphorylation of the membrane trafficking machinery as a key event associated with FER-mediated invasion

Triple Negative Breast Cancer (TNBC) is characterised by unfavourable outcome due to the combination of its metastatic propensity, chemo-refractory behaviour and the lack of effective targeted interventions. Expression of the feline sarcoma-related (FER) kinase constitutes an independent prognostic factor that correlates with poor patient survival. FER promotes invasive behaviour in TNBC cells by regulating endosomal sorting and recycling (ESR) of adhesion proteins. Yet, the ESR machinery supporting invasion in TNBC, particularly within 3D environments, remains poorly understood. Here, we used FER-expressing TNBC patient-derived xenograft organoids (PDXOs) and MDA-MB-231 cells to identify the membrane trafficking machinery promoting invasion. Using a combination of proteomics, phospho-proteomics, and single cell RNA-sequencing, we show that the invasion of FER-expressing PDXO cells in collagen-I is mainly associated with the differential phosphorylation of membrane trafficking regulators, including SEC16A and a marked increase in Rab4-positive tubules. SEC16A depletion impairs cell invasion and reduces the number of focal adhesions and Rab4-positive tubules. Importantly, FER regulates SEC16A levels and localization, specifically in TNBC. Altogether, we identified SEC16A as a key player in FER-driven TNBC invasion, highlighting the membrane trafficking machinery as a promising target for the development of new therapeutic strategies.

cancer biology↗
bioRxiv2025

Divergent roles of DNA methylation, TRIM28, and p53 surveillance in human embryonic and trophoblast stem cells

Transcriptional regulation of transposons and genes by TRIM28 and 5mC is critical for proper mammalian embryonic development, but the specific roles for these mediators in human embryonic and placental lineage remain unclear. We find that loss of TRIM28 has a limited effect on global transposon expression and instead results in upregulation of genes proximal to TRIM28-bound Long Terminal Repeats (LTRs) in both human trophoblast stem cells (hTSCs) and human embryonic stem cells (hESCs). MER11A elements show especially strong regulatory importance in hTSCs: these elements are bound by both TRIM28 and placental transcription factors and show both heterochromatic and euchromatic features. Some genes are positively regulated by MER11A elements in hTSC basal state, while other MER11A-proximal genes show upregulation only upon TRIM28 deletion. By contrast, loss of DNA methylation in hESCs or hTSCs leads to a global increase in transposon expression. While many genic 5mC targets are shared in hESCs and hTSCs, we also observe evidence that a handful of genes important for somatic development are repressed by 5mC in trophoblast, while a small parallel set of placental genes are repressed by methylation in embryonic tissue. Interestingly, loss of DNMT1 causes hESCs to be rapidly lost from culture in a TP53 and mitotic surveillance checkpoint-dependent manner, while hTSCs show little p53 response to DNMT1 loss or DNA damage generally, instead showing gradual mitotic defects and aneuploidy and slow loss from culture. This discrepancy may explain the higher frequency of karyotypic abnormality found in human placental cells. Together, this study charts the role of TRIM28 and DNA methylation in regulating embryonic and placental transcription and demonstrates divergent p53-dependent responses to genomic instability.

molecular biology↗
bioRxiv2025

Integrated Metabolic Complex Genetic Interaction 1 Network of Chromosome 4p Loss in Basal Breast Cancer

Basal breast cancer subtype is enriched for triple-negative breast cancer (TNBC) and exhibits a recurrent large chromosomal deletion in chromosome 4p (chr4p). Chr4p loss is associated with poor survival, evolves early in tumorigenesis and confers on cells a proliferative state. Here, we map the integrated metabolic complex genetic interaction network of chr4p in basal breast cancer to identify targetable vulnerabilities. Differential gene expression analysis of patient derived xenografts and cancer cell models revealed that chr4p loss is associated with changes in cellular energetics and reduction/oxidation balance. Analysis of DepMap pooled genome-wide CRISPR-Cas9 screens identified complex genetic interactions specific to chr4p deletion in basal breast cancer cell models. Functional assays revealed that chr4p loss is associated with disrupted mitochondrial respiratory function and reduced glycolytic capacity, suggesting metabolic rewiring. Increased reactive oxygen species and lipid peroxidation compromised antioxidant defense mechanisms. Ultimately, this study sheds light on targeted therapies for basal breast cancer harboring large chromosomal deletions.

genomics↗
bioRxiv2025

A Cross-scale Causal Mapping Framework Pinpoints Macrophage Orchestrators of Balanced Arterial Development

Postnatal pulmonary arteries experience an abrupt surge in flow that demands tightly coordinated remodeling of vascular structure and mechanical compliance. However, the cellular programs orchestrating these multiscale adaptation remain poorly defined, partly due to the absence of analytical tools integrating gene-cell-tissue scales. Here, we present CausaLink, a cross-scale causal mapping framework that predicts how altered gene expression propagates through gene-cell-tissue networks by integrating time-course transcriptomic and tissue morpho-mechanical data. We constructed a single-cell transcriptomic atlas of 11,143 proximal pulmonary artery-derived cells from C57BL/6J mice across five developmental stages (P2, P10, P21, P42, and P84), revealing dynamic lineage transitions and transient mesenchymal population specifying into fibroblasts and smooth muscle cells from P2 to P21. Using this framework, we identified Mgl2 macrophages as central regulators promoting lumen expansion while preventing pathological wall thinning or thickening. To validate these predictions, we established a human induced pluripotent stem cell-derived arterial assembloid enriched in MGLhigh macrophages. In this model, MGLhigh macrophages supported lumen enlargement while maintaining overall wall thickness and induced formation of an adventitia-like fibroblast layer that recapitulated approximately 80% of the native adventitial fraction with balanced collagen-elastin remodeling. By linking predictive modeling to human organoid validation, this study establishes a cross-scale workflow for tracing how gene programs shape vascular architecture, offering mechanistic insights and a foundation for predictive regenerative medicine.

bioengineering↗
bioRxiv2025

Rejuvenation-Responsive and Senolytic-Sensitive Muscle Stem Cells Unveiled by CD200 and CD63 in Geriatric Muscle

Muscle stem cells (MuSCs) are parenchymal cells in skeletal muscle regeneration and maintenance. With aging, MuSCs experience a decline in their regenerative function and reduction in their number. However, recent evidence points to substantial heterogeneity within the aged MuSC population, raising questions about the underlying mechanisms of age-associated dysfunction. Here, we used Pax7CreERT2;RosaYFP mice (MuSCYFP) to label Pax7-expressing MuSCs and chronologically traced MuSCs until geriatric age. Genetic labeling and chronological tracing revealed that the number of YFP+ MuSC remained comparable between young, middle and geriatric ages. At geriatric age, YFP+ MuSCs exhibited reduced expression of traditional MuSC markers such as VCAM1 and PAX7. A previously unrecognized subpopulation emerged, characterized by loss of VCAM1 and low or absent PAX7. Despite their altered marker profile, these cells retained transcriptional signatures of quiescence and myogenic potential, but displayed significantly reduced proliferative and regenerative capacities. They displayed gene expression patterns indicative of senescence-like state and were selectively ablated by senolytic treatment. DHT restored regenerative function in aged mice and re-induced VCAM1 expression in YFP+/Pax7-/low/VCAM1- cells, indicating responsiveness to rejuvenation. Based on their emergence with aging, functional impairment and responsiveness to rejuvenation, we termed this population GERI-MuSCs (Geriatric Emerging Rejuvenation-responsive and Impaired MuSCs). CD63 and CD200 were identified as novel surface markers that together with VCAM1, reliably detect GERI-MuSCs as well as classical Pax7+/VCAM1High MuSCs, providing a tool for comprehensive isolation of MuSCs from aged wild-type mice. Together, our findings provide a refined framework for studying MuSC aging and offer new tools for isolating functionally distinct MuSC subsets from aged skeletal muscle.

developmental biology↗
bioRxiv2025

A unified derivative-like dopaminergic computation across valences

Dopamine activity in the brain affects decision-making and adaptive behaviors. A wealth of studies indicate that dopamine activity encodes discrepancy between actual and predicted reward, leading to the reward prediction error (RPE) hypothesis. Specifically, it has been claimed that mesolimbic dopamine activity conforms to temporal-difference reward prediction error (TD RPE), a teaching signal in machine learning algorithms. Recently, there is growing evidence suggesting that dopamine is also involved in learning during aversive situations. However, the fundamental computation of dopamine activity in aversive situations is still unknown. A plausible but untested hypothesis is that dopamine activity in aversive situations also encodes TD RPE. Here, we tested this hypothesis by using mice in virtual reality. Mice were trained to avoid electrical tail shocks by running out of a virtual shock zone. Using probe conditions with speed manipulation or teleportation, we revealed that the dopamine signal in the ventral striatum follows the temporal derivative form of a value function. Delivering a reward at the end of the track enabled us to observe the integration of aversion and reward in a derivative form. Moreover, the value functions unbiasedly estimated from the recorded signal is consistent with the initial hypothetical form, with a realistic reflection of a received shock distribution. Taken together, our results show that mesolimbic dopamine activity can operate as a unified teaching signal in natural situations with positive and negative valences.

neuroscience↗
bioRxiv2025

In vivo and in silico alpha-synuclein propagation dynamics: The role of genotype, epicentre, and connectivity

Neurodegeneration observed in synucleinopathies, like Parkinsons disease (PD), are hypothesized to be a consequence of the progressive accumulation and spread of misfolded alpha-synuclein (aSyn) throughout the brain. Here, we study the generalizability of this hypothesis across multiple biologically-relevant factors including genotype, aSyn species, and regional vulnerability (i.e.: does the introduction of aSyn into different brain regions have a similar impact) using a detailed longitudinal brain (using magnetic resonance imaging; [MRI]) and behavioural approaches. We first examined wild-type and M83 A53T hemizygous transgenic (engineered to over-express human aSyn) C57BL/6 x C3H mice receiving striatal inoculation with human or mouse preformed fibrils (PFFs) (n=89 mice at the last time point; n=687 MRI). Longitudinal analyses demonstrated a time-dependent increase in network-like atrophy and motor deficits, generalized across genotype and PFF species. We further derived latent dimensions relating brain-behaviour relationships revealing a pattern of sex- and genotype-relevant atrophy. Overall, atrophy was most prominent in M83 mice with mouse PFFs, while human PFFs or wild-type hosts showed attenuated effects. Changing the inoculation site to the hippocampus, a major connectivity hub, revealed differential regional vulnerability in the form of localized atrophy. Computational models previously validated in clinical PD further indicated regional vulnerability with increased predictive ability for atrophy patterns associated with striatal compared to hippocampal inoculation. Our findings reveal atrophy resulting from aSyn spreading is generalizable across genotype and PFF species, but not disease epicentres, emphasizing the role of regional vulnerability in disease progression.

neuroscience↗
bioRxiv2025

Optimized large-scale longitudinal biorepository of gastroesophageal adenocarcinoma patient-derived organoids: High-fidelity models for personalized treatment to overcome resistance.

A major limitation in studying gastroesophageal adenocarcinoma (GEA) has been the lack of reliable models that represent the diseases complexity. We present lessons learned from a comprehensive large-scale biobanking effort combining traditional sample collection with several in vitro models including 3-dimensional patient-derived organoids (PDOs), 2-dimensional cancer-associated fibroblasts (CAFs), tumor-infiltrating lymphocytes (TILs) and/or in vivo xenografts. This initiative started in 2018, integrating multiple advanced ex-vivo models such as PDOs, patient-derived xenografts (PDXs) and organoids (PDXOs). This unique resource now includes tumor avatars from over 380 consented patients, making it the largest living GEA biobank in the world. We achieved > 90% success rate in creating per-patient models, including 227 tumor-derived and 203 neighboring normal PDOs. These organoids accurately mirror key features of the original tumors, such as their histology (e.g. microsatellite instability), mutations, and drug response, across treatment points. Notably, PDOs can predict individual patient responses to chemotherapy within five weeks, underscoring their clinical relevance. Furthermore, high-throughput drug screening on PDO subsets generates personalized chemosensitivity profiles for 22 drugs. Through a process of continued refinement of culture techniques and tumor sampling approach, our large-scale comprehensive collection of GEA avatars represents a unique and valuable preclinical experimental resource for precision oncology. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=76 SRC="FIGDIR/small/663874v1_ufig1.gif" ALT="Figure 1"> View larger version (28K): org.highwire.dtl.DTLVardef@f8a032org.highwire.dtl.DTLVardef@dd6fa3org.highwire.dtl.DTLVardef@1cc558corg.highwire.dtl.DTLVardef@492a5_HPS_FORMAT_FIGEXP M_FIG Schematic depiction of GEA live-banking workflow C_FIG

cancer biology↗
bioRxiv2025

Bidirectional regulation of glycoprotein nonmetastatic melanoma protein B by β-glucocerebrosidase deficiency in GBA1 isogenic dopaminergic neurons from a patient with Gaucher disease and parkinsonism

Variants in GBA1 are common genetic risk factors for several synucleinopathies. The increased risk has been attributed to the toxic effects of misfolded glucocerebrosidase (GCase) (gain-of-function), and the accumulation of lipid substrates due to reduced enzyme activity (loss-of-function). To delineate GBA1 pathogenicity, an iPSC line was generated from a patient with both type 1 Gaucher disease (GBA1: N370S/N370S; p.N409S/p.N409S) and Parkinson disease (PD). From this line, we created a reverted wild-type (WT) line and a GBA1 knockout (KO) line to eliminate misfolded GCase and intensify lipid accumulation. N370S/N370S and KO dopaminergic neurons (DANs) exhibited decreasing GCase levels and progressive accumulation of lipid substrates compared to WT DANs. Notably, the expression of GPNMB, whose levels correlate with PD risk, was upregulated by the mild lipid accumulation in N370S/N370S DANs but disrupted in KO DANs. These findings refine the loss-of-function mechanism by associating PD risk levels of GPNMB with lipid levels specific to GBA1 risk variants.

neuroscience↗
bioRxiv2025

Multimodal profiling unveils a reversible basal-like breast cancer cell state resistant to AKT inhibition

The PI3K/AKT/mTOR pathway is central to cell metabolism and growth. However, pharmacological inhibition of the pathway is not uniformly effective across cancer types, or even within a single cancer model. In this study, we leverage oblique plane microscopy of triple negative breast cancer organoids, as well as lineage tracing to uncover a source of heterogeneity. Non-genetic resistance to AKT inhibition is associated with basal cell features of normal breast epithelium and the master transcription factor of basal cell state, {Delta}Np63, is sufficient to confer resistance. Cells can transition between states within four weeks and therefore, AKT inhibition only delays tumour growth, with tumours rich in KRT14+ cells resulting. Thus, under selection, triple negative breast cancer exploits a repertoire of cell states inherent to the breast.

cancer biology↗
bioRxiv2025

Alternatively-Spliced CAMKK2 isoforms drive differential metabolic stress response and the regulation of ferroptosis

Calcium/Calmodulin-dependent protein kinase kinase 2 (CAMKK2) is a multifunctional kinase that regulates metabolic processes by phosphorylating downstream targets. CAMKK2 is expressed as several highly similar protein isoforms, although the specific functions of these individual isoforms remain largely unexplored. These isoforms have been shown to display tissue-specific expression patterns, suggesting unique roles in distinct cellular contexts. In this study, we investigated the biochemical and functional relevance of CAMKK2 isoforms, LF and SF, in the context of glucose metabolism. Co-immunoprecipitation experiments revealed that the LF isoform preferentially binds the adaptor protein 14-3-3, while the SF isoform interacts with Calmodulin. Furthermore, the interaction between SF and Calmodulin was enhanced upon glucose starvation, whereas this interaction was not observed for LF. To assess their functional significance, we generated doxycycline-inducible, isoform-specific HeLa cell lines. Under low glucose conditions, cells expressing the LF isoform failed to activate AMPK, while cells expressing the SF isoform exhibited robust increase in AMPK phosphorylation. Moreover, LF-expressing cells accumulated higher levels of reactive oxygen species, upregulated ferroptosis-related genes via BACH1/NRF2, and displayed increased cell death compared to SF-expressing cells. Collectively, these findings demonstrate that CAMKK2 isoforms exhibit differential selectivity for protein partners and mediate distinct downstream signaling pathways, impacting metabolism in cancer.

biochemistry↗
bioRxiv2025

14-3-3ϵ UFMylation promotes RIG-I-mediated signaling

Post-translational modifications regulate RIG-I signaling in diverse ways. We previously showed that UFMylation, the covalent attachment of the ubiquitin-fold modifier UFM1 to proteins, enhances RIG-I signaling by promoting its interaction with its membrane-targeting adaptor 14-3-3{varepsilon}. Here, we map UFM1 conjugation to lysines K50 and K215 on 14-3-3{varepsilon} and demonstrate how these UFMylation events control RIG-I signaling. Using in vitro and cellular UFMylation assays, we reveal that K50R/K215R mutations abolish UFMylation and reduce type I and III interferon induction following RIG-I activation. Unexpectedly, these mutations do not disrupt 14-3-3{varepsilon}-RIG-I interaction. Instead, they paradoxically enhance RIG-I interaction with MAVS while simultaneously reducing 14-3-3{varepsilon}-MAVS interaction. These findings establish UFMylation of 14-3-3{varepsilon} as an important control that shapes MAVS complex architecture to ensure optimal RIG-I signaling and highlights the broader regulatory role of UFMylation in antiviral innate immunity. ImportancePost-translational modifications provide regulatory control of antiviral innate immune responses. Our study reveals that UFMylation of 14-3-3{varepsilon} is required for RIG-I-mediated innate immune signaling. We demonstrate that conjugation of UFM1 to specific lysine residues on 14-3-3{varepsilon} enhances downstream signaling events that facilitate interferon induction. It does this by stabilizing 14-3-3{varepsilon} association with the MAVS signaling complex and coordinating productive complex architecture. By identifying the precise sites of UFMylation on 14-3-3{varepsilon} and their functional consequences, we provide insights into the regulatory layers governing antiviral innate immunity. These findings complement emerging evidence that UFMylation serves as a versatile modulator across diverse immune pathways. Furthermore, our work highlights how protein chaperones like 14-3-3{varepsilon} can be dynamically modified to orchestrate complex signaling cascades, suggesting potential therapeutic approaches for targeting dysregulated innate immunity.

immunology↗
bioRxiv2025

Examining Alzheimer's Disease Modifiable Risk Factors: Impact of Physical Activity and Diet on Neuroanatomy and Behaviour in Mice

Dementia is a global public health challenge, with obesity emerging as an important modifiable risk factor. Here, we examined whether lifestyle interventions can mitigate the effects of diet-induced obesity on body weight, behaviour, and brain anatomy in mouse models. Using a longitudinal design, wild-type and triple-transgenic (3xTgAD) mouse models of Alzheimers disease were exposed to a high-fat diet and assigned to one of three interventions: voluntary physical activity, a low-fat diet, and their combination. A high-fat diet significantly increased body weight and induced widespread neuroanatomical changes, with effects modulated by sex and genotype. The combined intervention led to significant weight loss in males of both genotypes. Neuroanatomical analyses revealed that a high-fat diet significantly reduced hippocampal and cerebellar volumes in wild-type mice but had a less pronounced effect on 3xTgAD mice; nevertheless, interventions, particularly the combined approach, increased localized brain volumes in these regions regardless of genotype. Multivariate integration of behavioural and neuroanatomical measures identified a brain pattern linking hippocampal and cerebellar volumes to intervention and behavioural performance. Spatial gene enrichment analysis of this pattern identified biological processes, including glucose homeostasis, as potential biological mechanisms underlying intervention effects. Overall, these findings suggest that voluntary physical activity and a low-fat diet can modulate brain structure and behaviour, partially counteracting the effects of a high-fat diet, and potentially recruiting biological processes that may support brain health.

neuroscience↗
bioRxiv2025

ATR and PKMYT1 inhibition re-sensitize a subset of TNBC patient-derived models to carboplatin inducing mitotic catastrophe

Triple negative breast cancer (TNBC) is associated with poor prognosis and is mainly treated with chemotherapy-based regimens, often including carboplatin. Resistance to carboplatin is a common clinical issue that is either initially present or develops with treatment. Overcoming this resistance is a significant clinical challenge, which highlights the need for novel therapeutic strategies. We used a pooled shRNA screening approach with a chemoresistant TNBC patient-derived xenograft (PDX) cell (PDXC) line to identify targets whose knockdown would enhance the efficacy of carboplatin. This screening led to the identification of the ATR (ataxia telangiectasia and Rad3-related) gene as a key therapeutic vulnerability. Inhibiting ATR with BAY1895344 or AZD6738 re-sensitized carboplatin-resistant PDXCs and PDXs to carboplatin, resulting in an increase in DNA damage, and apoptosis. ATR inhibition disrupts the dependence of carboplatin-resistant cells on the S and G2/M checkpoints for DNA repair, leading to mitotic catastrophe. We further found that the addition of ATR inhibitors to carboplatin reversed a FOXM1-targeted gene program enabling premature passage into mitosis. Moreover, targeting PKMYT1, a regulator of cyclin-dependent kinase 1 (CDK1) controlling the G2/M checkpoint, through knockdown or with the novel PKMYT1 inhibitor RP-6306, also enhanced carboplatin efficacy in our TNBC PDXC. Molecular factors associated with response to the ATR inhibitor/carboplatin combination included low RNA levels of PKMYT1. These results underscore the pivotal roles of ATR and PKMYT1 in mediating resistance to carboplatin in TNBC and support targeting these pathways to overcome carboplatin resistance in this disease.

cancer biology↗
bioRxiv2025

UFMylation promotes orthoflavivirus infectious particle production

Post-translational modifications play crucial roles in viral infections, yet many potential modifications remain unexplored in orthoflavivirus biology. Here we demonstrate that the UFMylation system, a post-translational modification system that catalyzes the transfer of UFM1 onto proteins, promotes infection by multiple orthoflaviviruses including dengue virus, Zika virus, West Nile virus, and yellow fever virus. We found that depletion of the UFMylation E3 ligase complex proteins UFL1 and UFBP1, as well as other UFMylation machinery components (UBA5, UFC1, and UFM1), significantly reduces infectious virion production for orthoflaviviruses but not the hepacivirus, hepatitis C. Mechanistically, UFMylation does not regulate viral RNA translation or RNA replication but instead affects a later stage of the viral lifecycle. We identified novel interactions between UFL1, and several viral proteins involved in orthoflavivirus virion assembly, including NS2A, NS2B-NS3, and Capsid. These findings establish UFMylation as a previously unrecognized post-translational modification system that promotes orthoflavivirus infection, likely through modulation of viral assembly. This work expands our understanding of the post-translational modifications that control orthoflavivirus infection and identifies new potential therapeutic targets. ImportanceOrthoflaviviruses depend on host-mediated post-translational modifications to successfully complete their lifecycle, yet many of these critical interactions remain undefined. Here, we describe a role for a post-translational modification pathway, UFMylation, in promoting infectious particle production of ZIKV and DENV. We show that UFMylation regulates these viruses at a lifecycle stage after initial RNA translation and RNA replication. Additionally, we find that regulation of infection by UFMylation extends to other orthoflaviviruses, including West Nile virus and yellow fever virus, but not to the broader Flaviviridae family. Finally, we demonstrate that UFMylation machinery directly interacts with specific DENV and ZIKV proteins during infection. These studies reveal a previously unrecognized role for UFMylation in regulating orthoflavivirus infection.

microbiology↗
bioRxiv2024

LAG3 marks activated but hyporesponsive NK cells.

Natural Killer (NK) cells are critical for immunosurveillance yet become dysfunctional in contexts such as chronic stimulation by viral infections or cancer. This phenomenon is similar to T cell exhaustion but less well characterized, which limits therapeutic interventions. As shown for T cells, NK cells often display an increased expression of immune checkpoint proteins (ICP) following chronic stimulation, and ICP blockade therapies are currently being explored for several cancer types, which have remarkable patient benefits. Nevertheless, the nature of ICP expression in NK cells is still poorly documented. In this study, we aimed to identify the conditions that lead to and the phenotype of immune checkpoint LAG3 (Lymphocyte-activation gene 3) expressing NK cells. Using various experimental models, we found that LAG3 is expressed by murine NK cells upon activation in different contexts, including in response to cancer and acute viral infections. LAG3 marks a subset of immature, proliferating and activated cells, which, despite activation, have a reduced capacity to respond to a broad range of stimuli. Further characterization also revealed that LAG3+ NK cells exhibit a transcriptional signature similar to that of exhausted CD8+ T cells. Taken together, our results support the use of LAG3 as a marker of dysfunctional NK cells across diverse chronic and acute inflammatory conditions.

immunology↗
bioRxiv2024

The sodium-glucose cotransporter 2 inhibitor tofogliflozin induces vasodilation by activating Kv channels, the SERCA pump, and the sGC/cGMP pathway

OBJECTIVETofogliflozin is a sodium-glucose cotransporter 2 (SGLT2) inhibitor widely used to treat T2DM, but it also exhibits cardio-protective effects. This study investigated the vasodilatory action of tofogliflozin using rabbit femoral artery rings pre-contracted with phenylephrine. APPROACH AND RESULTSThe femoral artery quickly separated from the rabbit and fix it to the organ bath chamber. Subsequently, administer an inhibitor that modulates vascular tension in the rings or remove the endothelium to assess its impact on vasodilation. The results showed the concentration-dependent induction of vasodilation by tofogliflozin, a response that remained unchanged following endothelial removal, pretreatment with the nitric oxide synthase (NOS) inhibitor L-NAME, or the inhibition of low- and intermediate-conductance Ca2+-activated K+ channels (SKCa and IKCa) using apamin in combination with TRAM-34. Furthermore, pretreatment with the voltage-dependent K+ (Kv) channel inhibitor 4-AP reduced the vasodilatory effects of tofogliflozin whereas pretreatment with the ATP-sensitive K+ (KATP) channel inhibitor glibenclamide or the large-conductance Ca2+-activated K+ (BKCa) channel inhibitor paxilline did not. Notably, our findings indicated that Kv7.X, rather than Kv1.5 or Kv2.1, is the primary Kv subtype involved in tofogliflozin-induced vasodilation. The vasodilatory effects of tofogliflozin were also significantly inhibited in femoral arterial rings pretreated with the sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) pump inhibitors thapsigargin and cyclopiazonic acid (CPA). Tofogliflozin-induced vasodilation was unaltered in arterial rings exposed to the adenylyl cyclase inhibitor SQ 22536, the protein kinase A (PKA) inhibitor KT 5720, and the protein kinase G (PKG) inhibitor KT 582 whereas it was effectively reduced by the soluble guanylyl cyclase (sGC) inhibitor ODQ. CONCLUSIONSThese findings suggest that tofogliflozin-induced vasodilation is mediated by the activation of the SERCA pump, the sGC/cGMP pathway, and Kv channels, but not the PKA signaling pathway, other K+ channels, or endothelium-dependent mechanisms.

pharmacology and toxicology↗