Biology subjects

Skladal, P.

Publications and source records attributed to Skladal, P..

5 recordsLinked to original sources

bioRxiv2024

Regulation of cell-nanoparticle interactions through mechanobiology

Bio-nano interactions have been extensively explored in nanomedicine to develop selective delivery strategies, reduce systemic toxicity, and minimize therapeutic dosing requirements. To enhance the delivery of nanocarriers to cancer cells and improve the therapeutic efficiency and clinical translation of nanomedicines, numerous nanomaterials with diverse and tunable properties have been developed. However, the limited clinical translation of nanoparticle-based therapies, largely due to issues associated with poor targeting and therapeutic delivery, requires a deeper understanding of the biological phenomena underlying cell-nanoparticle interactions. In this context, herein we investigate the molecular and cellular mechanobiology parameters that control such interactions. We demonstrate that the pharmacological inhibition or the genetic ablation of the key mechanosensitive component of the Hippo pathway, i.e., yes-associated protein, enhances nanoparticle internalization by 1.5-fold. Importantly, this phenomenon occurs independently of nanoparticle properties, such as size, or cell properties such as surface area, substrate adhesion, and stiffness. Our study reveals that the internalization of nanoparticles in target cells can be controlled by modulating cell mechanosensing pathways, potentially ultimately enhancing nanoparticle delivery and nanotherapy specificity.

bioengineering↗

bioRxiv2023

YAP signaling regulates the cellular uptake and therapeutic effect of nanoparticles

Interactions between living cells and nanoparticles have been extensively studied to enhance the delivery of therapeutics. Nanoparticles size, shape, stiffness and surface charge have been regarded as the main features able to control the fate of cell-nanoparticle interactions. However, the clinical translation of nanotherapies has so far been limited, and there is a need to better understand the biology of cell-nanoparticle interactions. This study investigated the role of cellular mechanosensitive components in cell-nanoparticle interactions. We demonstrate that the genetic and pharmacologic inhibition of yes-associated protein (YAP), a key component of cancer cell mechanosensing apparatus and Hippo pathway effector, improves nanoparticle internalization in triple-negative breast cancer cells regardless of nanoparticle properties or substrate characteristics. This process occurs through YAP-dependent regulation of endocytic pathways, cell mechanics, and membrane organization. Hence, we propose targeting YAP may sensitize triple negative breast cancer cells to chemotherapy and increase the selectivity of nanotherapy.

bioengineering↗

bioRxiv2023

FGF2-induced Redox Signaling: A Mechanism Regulating Pyruvate Dehydrogenase Driven Histone Acetylation and NANOG Upregulation

Precise control of pluripotency is a requirement for the safe and effective use of hPSCs in research and therapies. Here we report that pyruvate dehydrogenase upregulates histone H3 pan acetylation and levels of pluripotency marker NANOG in 5% O2. Pyruvate dehydrogenase (PDH) is an essential metabolic switch and a bottleneck for the glycolytic production of acetyl-CoA. Silencing of gene expression showed that PDH is regulated by the activity of its phosphatase PDP1. We show that PDP1 is sensitive to reactive oxygen species-mediated inactivation, leading to the downregulation of H3 pan acetylation and NANOG levels. Furthermore, we show that FGF2, a cytokine commonly used to maintain pluripotency activates pyruvate dehydrogenase through MEK1/2-ERK1/2 signaling pathway-mediated downregulation of ROS in 5% O2, thus promoting histone acetylation. Our results show the importance of pyruvate dehydrogenase in regulating energy metabolism and its connection to pluripotency. Furthermore, our data highlight the role of reactive oxygen species and redox homeostasis in pluripotency maintenance and differentiation. Highlights- PDP1-induced activation of PDH leads to increased histone H3 pan acetylation and NANOG levels in hPSCs - Reactive oxygen species (ROS) inactivate PDP1 and decrease histone H3 pan acetylation and NANOG levels in hPSCs - MEK1/2-ERK1/2 signaling-mediated downregulation of ROS in 5% O2 activates PDH in hPSCs Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=129 SRC="FIGDIR/small/524871v1_ufig1.gif" ALT="Figure 1"> View larger version (39K): org.highwire.dtl.DTLVardef@133f8dcorg.highwire.dtl.DTLVardef@1176d94org.highwire.dtl.DTLVardef@11b153corg.highwire.dtl.DTLVardef@10f2e4d_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

bioRxiv2022

Dual role of Pectin Methyl Esterase activity for plant cell growth regulation.

Acid-growth theory has been postulated in the 70s to explain the rapid elongation of cells in response to plant hormone auxin. More recently, it has been demonstrated that activation of the proton ATPs pump (H+-ATPs) promoting acidification of the apoplast is the principal mechanism through which hormones like auxin as well as brassinosteroids (BR) induce cell elongation. However, the impact of this acidification on the mechanical properties of the cell wall remained largely unexplored. Here, we use Atomic Force Microscopy (AFM) to demonstrate that acidification of apoplast is necessary and sufficient to induce cell elongation through cell wall relaxation. Moreover, we demonstrate that Pectin Methyl Esterase (PME) can induce both cell wall softening or stiffening in extracellular calcium dependent-manner and that tight control of PME activity is required for hypocotyl elongation.

cell biology↗

bioRxiv2020

PDZ and LIM domain protein 2 plays dual and context-dependent roles in breast cancer development

ABSTRACTO_ST_ABSBackgroundC_ST_ABSPDZ and LIM domain protein 2 (PDLIM2) is a cytoskeletal and nuclear effector that regulates the activity of several transcription factors (e.g., NF-{kappa}B, STAT), and its deregulation has been associated with oncogenesis. Our recent study identified PDLIM2 as a protein associated with the lymph node metastasis of low grade luminal A breast cancer tissues. Here, we aim to understand this association at the molecular and cellular levels. MethodsTo investigate the link between PDLIM2 and epithelial-to-mesenchymal transition (EMT), stably transduced MCF7-PDLIM2 cells, and MCF7 or MCF10A cells with PDLIM2 protein levels modified using siRNA or PDLIM2 gene carrying plasmid, were used. Additionally, MCF7 and MCF10A cells were exposed to hypoxic conditions and TGF{beta}1 treatment. EMT was monitored using immunoblotting of EMT markers and atomic force microscopy (AFM). The role of PDLIM2 in cell migration and/or invasion was investigated using Transwell assay and xCELLigence system. ResultsFirst, we observe a positive effect of PDLIM2 overexpression on EMT in MCF7 cells, a model of luminal A tumors, using EMT markers and AFM. On the other hand, PDLIM2 helps to maintain the epithelial phenotype in MCF10A cells, a model of normal breast epithelial cells. Second, we find that exposure of the MCF7 cells to hypoxic conditions increases levels of PDLIM2 and carbonic anhydrase-9 (CA-9), a marker of the response to hypoxia. However, none of these effects are observed in the MCF10A cells. Third, PDLIM2 overexpression promotes migration, invasion, and proliferation and decreases adhesion of the MCF7 cells, but an opposite effect is observed in the MCF10A cells. ConclusionsOur data indicate that PDLIM2 plays a dual role: (i) as an EMT-supporting and hypoxia-responding oncoprotein in luminal breast cancer cells, and (ii) as an epithelial phenotype-maintaining tumor suppressor in normal epithelial breast cells.

cancer biology↗