Jennifer Hyunjong Shin

The organization of individual actin filaments into higher-order structures is controlled by actin-binding proteins (ABPs). Although the biological significance of the ABPs is well documented, little is known about how bundling and cross-linking quantitatively affect the microstructure and mechanical properties of actin networks. Here we quantify the effect of the ABP scruin on actin networks by using imaging techniques, cosedimentation assays, multiparticle tracking, and bulk rheology. We show

The effect of MDR1 G2677T/C3435T haplotypes on fexofenadine disposition are magnified in the presence of itraconazole. Itraconazole pretreatment significantly altered the disposition of fexofenadine and thus its peripheral antihistamine effects.

Caenorhabditis elegans (C. elegans) is a model organism widely utilized in various fundamental studies in developmental, neural and behavioural biology. The worm features four distinct larval stages, and many research questions are stage-specific; therefore, it is necessary to sort worms by their developmental stages, which are typically represented by different size ranges. However, manually synchronizing large populations of worms is time-consuming and labour-intensive, and the commercially av

Normal healing of skin wounds involves a complex interplay between many different cellular constituents, including keratinocytes, immune cells, fibroblasts, myofibroblasts, as well as extracellular matrices. Especially, fibroblasts play a critical role in regulating the immune response and matrix reconstruction by secreting many cytokines and matrix proteins. Myofibroblasts, which are differentiated form of fibroblasts, feature high cellular contractility and encourage the synthesis of matrix pr

The expansion of autologous chondrocytes in vitro is used to generate sufficient populations for cell-based therapies. However, during monolayer culture, chondrocytes lose inherent characteristics and shift to fibroblast-like cells as passage number increase. Here, we investigated passage-dependent changes in cellular physiology, including cellular morphology, motility, and gene and protein expression, as well as the role of focal adhesion and cytoskeletal regulation in the dedifferentiation pro

Engineered muscular substitutes can restore the impaired muscle functions when integrated properly into the host tissue. To generate functional muscles with sufficient contractility at the site of transplant, the in vitro construction of fully differentiated muscle fibers would be desired. Many previous reports have identified either topographical alignment or electrical stimulation as an effective tool to promote myogenic differentiation. However, optimization of spatial and temporal arrangemen

Although bacterial cancer targeting in animal models has been previously demonstrated and suggested as a possible therapeutic tool, a thorough understanding of the mechanisms responsible for cancer specificity would be required prior to clinical applications. To visualize bacterial preference for cancer cells over normal cells and to elucidate the cancer-targeting mechanism, a simple microfluidic platform has been developed for in vitro studies. This platform allows simultaneous cultures of mult

Cells are inherently exposed to a number of different biophysical stimuli such as electric fields, shear stress, and tensile or compressive stress from the extracellular environment in vivo. Each of these biophysical cues can work simultaneously or independently to regulate cellular functions and tissue integrity in both physiological and pathological conditions. Thus, it is vital to understand the interaction of multiple stimuli on cells by decoupling and coupling the stimuli in simple combinat

Hepatocyte growth factor (HGF) induces cell migration and scattering by mechanisms that are thought to tip a local balance of competing physical forces; cell-to-cell and cell-to-substrate forces. In this local process, HGF is known to attenuate local cadherin-dependent adhesion forces for cell-cell junction development and enhance local integrin-dependent contractile forces for pulling neighboring cells apart. Here we use an expanding island of confluent Madin-Darby canine kidney (MDCK) cells as

During the 5 s of the acrosome reaction of Limulus polyphemus sperm, a 60-microm-long bundle of scruin-decorated actin filaments straightens from a coiled conformation and extends from the cell. To identify the motive force for this movement, we examined the possible sources of chemical and mechanical energy and show that the coil releases approximately 10-13 J of stored mechanical strain energy, whereas chemical energy derived from calcium binding is approximately 10-15 J. These measurements in