Multiplexed single-cell imaging reveals diverging subpopulations with distinct senescence phenotypes during long-term senescence induction.

Cellular senescence is a phenotypic state that contributes to the progression of age-related disease through secretion of pro-inflammatory factors known as the senescence associated secretory phenotype (SASP). Understanding the process by which healthy cells become senescent and develop SASP factors is critical for improving the identification of senescent cells and, ultimately, understanding tissue dysfunction. Here, we reveal how the duration of cellular stress modulates the SASP in distinct subpopulations of senescent cells.

Third generation impedimetric sensor employing direct electron transfer type glucose dehydrogenase.

Faradaic electrochemical impedance spectroscopy (faradaic EIS) is an attractive measurement principle for biosensors. However, there have been no reports on sensors employing direct electron transfer (DET)-type redox enzymes based on faradaic EIS principle. In this study, we have attempted to construct the 3rd-generation faradaic enzyme EIS sensor, which used DET-type flavin adenine dinucleotide (FAD) dependent glucose dehydrogenase (GDH) complex, to elucidate its characteristic properties as well as to investigate its potential application as the future immunosensor platform.

Development of a third-generation glucose sensor based on the open circuit potential for continuous glucose monitoring.

Continuous glucose monitoring (CGM) systems are most important in the current Type I diabetes care and as component for the development of artificial pancreas systems because the amount of insulin being supplied is calculated based on the CGM results. Therefore, to stably and accurately control the blood glucose level, CGM should be stable and accurate for a long period. We have been engaged in the biomolecular engineering and application of FAD dependent glucose dehydrogenase complex (FADGDH) which is capable of direct electron transfer.

Rational Design of a Dephosphorylation-Resistant Reporter Enables Single-Cell Measurement of Tyrosine Kinase Activity.

Although peptide-based reporters of protein tyrosine kinase (PTK) activity have been used to study PTK enzymology in vitro, the application of these reporters to intracellular conditions is compromised by their dephosphorylation, preventing PTK activity measurements. Nonproteinogenic amino acids may be utilized to rationally design selective peptidic ligands by accessing greater chemical and structural diversity than is available using the native amino acids. We describe a peptidic reporter that, upon phosphorylation by the epidermal growth factor receptor (EGFR), is resistant to dephosphorylation both in vitro and in cellulo.

Small sample sorting of primary adherent cells by automated micropallet imaging and release.

Primary patient samples are the gold standard for molecular investigations of tumor biology yet are difficult to acquire, heterogeneous in nature and variable in size. Patient-derived xenografts (PDXs) comprised of primary tumor tissue cultured in host organisms such as nude mice permit the propagation of human tumor samples in an in vivo environment and closely mimic the phenotype and gene expression profile of the primary tumor. Although PDX models reduce the cost and complexity of acquiring sample tissue and permit repeated sampling of the primary tumor, these samples are typically contaminated by immune, blood, and vascular tissues from the host organism while also being limited in size.