Biology subjects

Shin, J.-W.

Publications and source records attributed to Shin, J.-W..

6 recordsLinked to original sources

bioRxiv2024

Matrimeres are systemic nanoscale mediators of tissue integrity and function

Tissue barriers must be rapidly restored after injury to promote regeneration. However, the mechanism behind this process is unclear, particularly in cases where the underlying extracellular matrix is still compromised. Here, we report the discovery of matrimeres as constitutive nanoscale mediators of tissue integrity and function. We define matrimeres as non-vesicular nanoparticles secreted by cells, distinguished by a primary composition comprising at least one matrix protein and DNA molecules serving as scaffolds. Mesenchymal stromal cells assemble matrimeres from fibronectin and DNA within acidic intracellular compartments. Drawing inspiration from this biological process, we have achieved the successful reconstitution of matrimeres without cells. This was accomplished by using purified matrix proteins, including fibronectin and vitronectin, and DNA molecules under optimal acidic pH conditions, guided by the heparin-binding domain and phosphate backbone, respectively. Plasma fibronectin matrimeres circulate in the blood at homeostasis but exhibit a 10-fold decrease during systemic inflammatory injury in vivo. Exogenous matrimeres rapidly restore vascular integrity by actively reannealing endothelial cells post-injury and remain persistent in the host tissue matrix. The scalable production of matrimeres holds promise as a biologically inspired platform for regenerative nanomedicine.

bioengineering↗

bioRxiv2023

Tension sensing by FAK governs nuclear mechanotransduction, endothelial transcriptome and fate

Vascular endothelium forms a restrictive barrier to defend the underlying tissue against uncontrolled influx of circulating protein and immune cells. Mechanisms that mediate the transition from restrictive to leaky endothelium, a hallmark of tissue injury exemplified by acute lung injury (ALI), remain elusive. Using endothelial cell (EC)-Fak-/-mice, we show that FAK sensing and transmission of mechanical tension to the EC nucleus governs cell fate. In FAK- deleted EC, increased EC tension induced by Rho kinase caused tyrosine phosphorylation of nuclear envelope protein, emerin at Y74/Y95, and its localization in a nuclear cap. Activated emerin stimulated DNMT3a activity and methylation of the KLF2 promoter, impairing the restrictive EC transcriptome, including S1PR1. Inhibiting emerin phosphorylation or DNMT3a activity enabled KLF2 transcription of S1PR1, rescuing the restrictive EC phenotype in EC-Fak-/- lungs. Thus, FAK sensing of tension transmission to the nucleus is crucial for maintaining a restrictive EC fate and lung homeostasis.

cell biology↗

bioRxiv2023

Manipulation of the nucleoscaffold potentiates cellular reprogramming kinetics

Somatic cell fate is an outcome set by the activities of specific transcription factors and the chromatin landscape and is maintained by gene silencing of alternate cell fates through physical interactions with the nuclear scaffold. Here, we evaluate the role of the nuclear scaffold as a guardian of cell fate in human fibroblasts by comparing the effects of transient loss (knockdown) and mutation (progeria) of functional Lamin A/C, a core component of the nuclear scaffold. We observed that Lamin A/C deficiency or mutation disrupts nuclear morphology, heterochromatin levels, and increases access to DNA in lamina-associated domains. Changes in Lamin A/C were also found to impact the mechanical properties of the nucleus when measured by a microfluidic cellular squeezing device. We also show that transient loss of Lamin A/C accelerates the kinetics of cellular reprogramming to pluripotency through opening of previously silenced heterochromatin domains while genetic mutation of Lamin A/C into progerin induces a senescent phenotype that inhibits the induction of reprogramming genes. Our results highlight the physical role of the nuclear scaffold in safeguarding cellular fate.

cell biology↗

bioRxiv2021

Niche-guided tissue patterning by chemomechanical flow lithography

Stem-cell derived tissue models are commonly cultured under globally-delivered stimuli that trigger histogenesis via self-organizing activity. However, the culture of such tissue models is prone to stochastic behavior, limiting the reproducibility of cellular composition and resulting in non-physiological architectures. To overcome these shortcomings, we developed a method for printing cell niche microenvironments with microstructured cues that mediate local histogenic processes, including mechanosensing and differentiation of selected cell types. Microstructured cues include independently tunable mechano-chemical properties, with conjugated peptides, proteins, and morphogens across a range of Youngs moduli. By rationally designing niches, we mediate the structure of tissues derived from stem-cell-progenitor sources, including a bone-fat assembly from stromal mesenchyme, and embryonic tissues derived from hiPSC. We show that microstructured cues can recapitulate mechano-chemical signals resembling early embryonic histogenesis. This outcome includes a role for niche mechanics in human embryonic organization, where soft niche mechanics bias markers of mesendodermal differentiation and epithelial-to-mesenchymal-transition (EMT), as well as a demonstration of a material-mediated morphogen signaling centers able to induce foci of mesenchymal and EMT differentiation. Thus, microstructured materials can mediate local histogenic processes to enhance the structure and composition of tissue models.

bioengineering↗

bioRxiv2018

Calotropis gigantea extract induces apoptosis through extrinsic/intrinsic pathways and upregulation of reactive oxygen species in non-small-cell lung cancer cells

BackgroundCalotropis gigantea (CG) plant grows in Asia and tropical Africa. However, the precise mechanisms of its anticancer effects have not yet been examined in human non-small cell lung cancer (NSCLC) cells, A549 and NCI-H1299 cells.\n\nPurposeThis study was focused on the anti-cancer effects of CG extract on non-small cell lung cancer (NSCLC) cells.\n\nMethodsThe cytotoxic effects of CG extract on NSCLC, A549 and NCI-H1299 cells, were detected by MTS assay, microscope and DAPI staining. Apoptosis was determined by annexin V-FITC/PI staining, cell cycle analysis, western blotting, quantitative polymerase chain reaction, and JC-1 staining.\n\nResultsFirst, CG showed significant dose-dependent cytotoxicity in NSCLC, A549, and NCI-H1299 cells. In addition to induction of caspase-8 processing, CG induced apoptosis by upregulating mRNA expression levels of extrinsic pathway molecules such as Fas, Fas ligand (FasL), Fas-associated protein with death domain (FADD) and death receptor 5 (DR5). Also, mitochondrial membrane potential (MMP) was collapsed, and intrinsic pathway molecules such as poly (ADP-ribose) polymerase (PARP), caspase-3, and caspase-9 were processed by CG. Moreover, reactive oxygen species (ROS) were generated in a CG dose-dependent manner, and inhibition of ROS by NAC, ROS scavenger, recovered A549 and NCI-H1299 cell viability.\n\nConclusionThese results indicate that CG causes apoptosis by activating the extrinsic and intrinsic pathways and generating ROS in NSCLC cells. These results suggest that CG can be used as a lung cancer therapeutic agent.

cancer biology↗

bioRxiv2017

(E)-2-Benzylidene-3-(cyclohexylamino)-2,3-dihydro-1H-inden-1-one (BCI) Induces Apoptosis Via The Intrinsic Pathway In H1299 Lung Cancer Cells

(E)-2-benzylidene-3-(cyclohexylamino)-2,3-dihydro-1H-inden-1-one (BCI) is known as a dual specific phosphatase 1/6 or MAPK inhibitor. However, its precise anti-lung cancer mechanism remains unknown. In this study, the effects of BCI on cell viability were investigated in the non-small cell lung cancer cell lines NCI-H1299, A549, and NCI-H460. We confirmed that BCI significantly inhibited the cell viability of NCI-H1299 compared to those of NCI-H460 and A549 cells. The anti-cancer effects of BCI were evaluated by MTS assay, annexin V-fluorescein isothiocyanate/propidium iodide staining, cell cycle analysis, reverse transcription-PCR, western blotting, and JC-1 staining in NCI-H1299 cells. BCI induced cellular morphological changes and inhibited viability of NCI-H1299 cells in a dose-dependent manner. BCI enhanced Bax expression and induced processing of caspase-9, caspase-3, and poly (ADP-ribose) polymerase as well as the release of cytochrome c from the mitochondria into the cytosol. BCI also down-regulated Bcl-2 expression but enhanced Bax expression in a dose-dependent manner in NCI-H1299 cells. In addition, BCI did not modulate death receptor expression or the extrinsic factor caspase-8 and Bid, a linker between the intrinsic and extrinsic apoptotic pathways in NCI-H1299 cells. On the basis of these results, we conclude that BCI induces apoptosis through a mediated intrinsic pathway, but not extrinsic pathway in NCI-H1299 cells. These results suggest that BCI can be used as a therapeutic agent in lung cancer.

pharmacology and toxicology↗