Calcium transients trigger switch-like discharge of prostaglandin E in an extracellular signal-regulated kinase-dependent manner.

Prostaglandin E (PGE) is a key player in a plethora of physiological and pathological events. Nevertheless, little is known about the dynamics of PGE secretion from a single cell and its effect on the neighboring cells. Here, by observing confluent Madin-Darby canine kidney (MDCK) epithelial cells expressing fluorescent biosensors, we demonstrate that calcium transients in a single cell cause PGE-mediated radial spread of PKA activation (RSPA) in neighboring cells.

Generation of transgenic mice expressing a FRET biosensor, SMART, that responds to necroptosis.

Necroptosis is a regulated form of cell death involved in various pathological conditions, including ischemic reperfusion injuries, virus infections, and drug-induced tissue injuries. However, it is not fully understood when and where necroptosis occurs in vivo. We previously generated a Forster resonance energy transfer (FRET) biosensor, termed SMART (the sensor for MLKL activation by RIPK3 based on FRET), which monitors conformational changes of MLKL along with progression of necroptosis in human and murine cell lines in vitro.

Intravital imaging reveals cell cycle-dependent myogenic cell migration during muscle regeneration.

During muscle regeneration, extracellular signal-regulated kinase (ERK) promotes both proliferation and migration. However, the relationship between proliferation and migration is poorly understood in this context. To elucidate this complex relationship on a physiological level, we established an intravital imaging system for measuring ERK activity, migration speed, and cell-cycle phases in mouse muscle satellite cell-derived myogenic cells.

A Highly Sensitive FRET Biosensor for AMPK Exhibits Heterogeneous AMPK Responses among Cells and Organs.

AMP-activated protein kinase (AMPK), a master regulator of cellular metabolism, is a potential target for type 2 diabetes. Although extensive in vitro studies have revealed the complex regulation of AMPK, much remains unknown about the regulation in vivo. We therefore developed transgenic mice expressing a highly sensitive fluorescence resonance energy transfer (FRET)-based biosensor for AMPK, called AMPKAR-EV.

Intravital Förster resonance energy transfer imaging reveals osteopontin-mediated polymorphonuclear leukocyte activation by tumor cell emboli.

Myeloid-derived suppressor cells (MDSCs) cause paraneoplastic leukemoid reactions and facilitate tumor cell metastasis. However, the interaction of MDSCs with tumor cells in live tissue has not been adequately visualized. To accomplish this task, we developed an intravital imaging protocol to observe metastasized tumor cells in mouse lungs.

Live imaging of transforming growth factor-β activated kinase 1 activation in Lewis lung carcinoma 3LL cells implanted into syngeneic mice and treated with polyinosinic:polycytidylic acid.

Transforming growth factor-β activated kinase 1 (TAK1) has been shown to play a crucial role in cell death, differentiation, and inflammation. Here, we live-imaged robust TAK1 activation in Lewis lung carcinoma 3LL cells implanted into the s.c.

[Cricoarytenoid arthritis diagnosed after tracheostomy in a rheumatoid arthritis patient].

A 65-year-old woman was scheduled for total knee replacement. She had been suffering from rheumatoid arthritis for 22 years. She also had a history of occasional acute dyspnea, which had been diagnosed as asthmatic bronchitis.