Simple Display System of Mechanical Properties of Cells and Their Dispersion

The mechanical properties of cells are unique indicators of their states and functions. Though, it is difficult to recognize the degrees of mechanical properties, due to small size of the cell and broad distribution of the mechanical properties. Here, we developed a simple virtual reality system for presenting the mechanical properties of cells and their dispersion using a haptic device and a PC. This system simulates atomic force microscopy (AFM) nanoindentation experiments for floating cells in virtual environments. An operator can virtually position the AFM spherical probe over a round cell with the haptic handle on the PC monitor and feel the force interaction. The Young's modulus of mesenchymal stem cells and HEK293 cells in the floating state was measured by AFM. The distribution of the Young's modulus of these cells was broad, and the distribution complied with a log-normal pattern. To represent the mechanical properties together with the cell variance, we used log-normal distribution-dependent random number determined by the mode and variance values of the Young's modulus of these cells. The represented Young's modulus was determined for each touching event of the probe surface and the cell object, and the haptic device-generating force was calculated using a Hertz model corresponding to the indentation depth and the fixed Young's modulus value. Using this system, we can feel the mechanical properties and their dispersion in each cell type in real time. This system will help us not only recognize the degrees of mechanical properties of diverse cells but also share them with others

Self-Organized Synchronous Calcium Transients in a Cultured Human Neural Network Derived from Cerebral Organoids

The cerebrum is a major center for brain function, and its activity is derived from the assembly of activated cells in neural networks. It is currently difficult to study complex human cerebral neuronal network activity. Here, using cerebral organoids, we report self-organized and complex human neural network activities that include synchronized and non-synchronized patterns. Self-organized neuronal network formation was observed following a dissociation culture of human embryonic stem cell-derived cerebral organoids. The spontaneous individual and synchronized activity of the network was measured via calcium imaging, and subsequent analysis enabled the examination of detailed cell activity patterns, providing simultaneous raster plots, cluster analyses, and cell distribution data. Finally, we demonstrated the feasibility of our system to assess drug-inducible dynamic changes of the network activity. The comprehensive functional analysis of human neuronal networks using this system may offer a powerful tool to access human brain function

ショクドウガン ジュツゴ ソウキ ニ キカン イカンロウ オ ガッペイ シタ 1レイ

The patient was a４５-year-old man. He had suffered from nephrotic syndrome at time of his twenties and had steroid salvage treatment. But he retired the treatment by himself. Esophageal tumor was suspected at the screening, and he was referred to our hospital. Preoperative diagnosis was the adenocarcinoma of the esophagogastric junction（cT２N０M０ stage Ⅱ）． Thoracoscopy assisted subtotal esophagectomy in prone position with D２dissection was performed. Gastric role was prepared in laparoscopic approach, and pulled up to the neck via posterior mediastinal route. Although early postoperative course was uneventful and esophageal fluoroscopy on the７th day showed no leakage, sudden dyspnea appeared on the８th day. CT examination and Bronchoscopy showed tracheoesophageal fistula. Unfortunately, the fistula didn’t get well, and we considered that it was difficult to close the fistula by only conservative treatment. Esophageal covered stent was inserted on the５６th day. After that, he could start ingestion intake and was discharged from hospital on the８５th day. Now, he is being followed up in our hospital

チュウスイ ゲンパツ フクゴウガタ セン シンケイ ナイブンピツ ガン ノ イチチケンレイ

A５２-year-old man visited our hospital because of epigastralgia. The colonoscopic examination revealed an about ４cm-protruded lesion like SMT on the appendix and findings of the biopsy specimen were compatible with the disgnosis of signet ring cell carcinoma. The primary lesion was unknown by upper gastrointestinal endoscopy, CT and PET, and the tumor markers were normal revel. At laparotomy, severe peritoneal metastasis was revealed in the abdominal cavity, especially appendix. Severe stenosis of ileocecum was found, so we conducted ileocecal resection. The histopathological diagnosis was primary signet ring cell caicinoma of appendix, SE, N２, M０, P３, pStage Ⅳ. Postoperatively mFOLFOX was started, but allergic reaction was seen after１cycle. We started Panitumumab/CPT-１１and the patient attended our emergency department with shivering chill and fever on treatment day１０. The next day he became shock state and CT revealed free air. Operation might not save his life and we started supportive care. He died on the day. The cause of his death was peritonitis by cancer perforation

Culture substrate-associated YAP inactivation underlies chondrogenic differentiation of human induced pluripotent stem cells

Human induced pluripotent stem cells (hiPSCs) are a promising cell source for the creation of cartilage to treat articular cartilage damage. The molecular mechanisms that translate culture conditions to the chondrogenic differentiation of hiPSCs remain to be analyzed. To analyze the effects of culture substrates, we chondrogenically differentiated hiPSCs on Matrigel or laminin 511-E8 while holding the composition of the chondrogenic medium constant. Cartilage was formed from hiPSCs on Matrigel, but not on laminin 511-E8. On Matrigel, the hiPSCs were round and yes-associated protein (YAP) was inactive. In contrast, on laminin 511-E8, the hiPSCs were flat and YAP was active. Treating the laminin 511-E8 hiPSCs in a bioreactor caused cell aggregates, in which the cells were round and YAP was inactive. Subsequent culture of the aggregates in chondrogenic medium resulted in cartilage formation. Transient knockdown of YAP in hiPSCs around the start of chondrogenic differentiation successfully formed cartilage on laminin 511-E8, suggesting that the activation of YAP is responsible for the failure of cartilage formation from hiPSCs on laminin 511-E8. Consistently, the addition of YAP inhibitors to laminin 511-E8 hiPSCs caused partial cartilage formation. This study contributes to identifying the molecules that mediate the effects of culture substrates on the chondrogenic differentiation of hiPSCs as well as to developing clinically applicable chondrogenic differentiation methods

A role of the sphingosine-1-phosphate (S1P)-S1P receptor 2 pathway in epithelial defense against cancer (EDAC)

At the initial step of carcinogenesis, transformation occurs in single cells within epithelia, where the newly emerging transformed cells are surrounded by normal epithelial cells. A recent study revealed that normal epithelial cells have an ability to sense and actively eliminate the neighboring transformed cells, a process named epithelial defense against cancer (EDAC). However, the molecular mechanism of this tumor-suppressive activity is largely unknown. In this study, we investigated a role for the sphingosine-1-phosphate (S1P)-S1P receptor 2 (S1PR2) pathway in EDAC. First, we show that addition of the S1PR2 inhibitor significantly suppresses apical extrusion of RasV12-transformed cells that are surrounded by normal cells. In addition, knockdown of S1PR2 in normal cells induces the same effect, indicating that S1PR2 in the surrounding normal cells plays a positive role in the apical elimination of the transformed cells. Of importance, not endogenous S1P but exogenous S1P is involved in this process. By using FRET analyses, we demonstrate that S1PR2 mediates Rho activation in normal cells neighboring RasV12-transformed cells, thereby promoting accumulation of filamin, a crucial regulator of EDAC. Collectively these data indicate that S1P is a key extrinsic factor that affects the outcome of cell competition between normal and transformed epithelial cells

The Biocompatible Anchor for Membrane (BAM) system.

<p>(A) Chemical structure of BAM. It comprises an oleyl group, an NHS reactive ester group, and a hydrophilic PEG linker. (B) Diagram of the BAM-coated substrate. BAM molecules are fixed on the BSA-coated substrate via coupling with the NHS ester of BAM to the amino group of BSA. The surface oleyl group enters the plasma membrane of the cell. Then, the cell is anchored onto the BAM substrate. (C) Phase contrast micrograph of hMSCs on the BAM substrate. The floating cells were anchored to the substrate, maintaining their round shape. The left upper object is the AFM cantilever.</p