Cell medicine最新文献

Positioning single cells on a solid surface is a crucial technique for understanding the cellular functions and cell-cell interactions in cell culture assays. We developed a microfluidic chip for depositing single cells in microwells using a simple micropipette operation. Cells were delivered to microwells by the meniscus motion of liquid interface. The residue deposits of cells were redistributed with air injection, and the isolated single cells were stored in microwells. Different microwell sizes and depths were studied to evaluate the trapping possibility of cells. Medium replacement and cell viability staining with the isolated single cells were achieved in microwells. The chip will serve as a tool for single-cell patterning in an easy-to-use manner.

Freezing is recognized as the most effective method of maintaining a stable supply of various cell types for long-term storage. However, cells might be damaged by environmental changes during the freezing process. There are various factors that influence the function of cells cultured after cryopreservation and thawing. These factors include cryopreservation solutions, biomaterials, freezing methods, and the freezing and preservation temperatures. There is also a risk of infection with mycoplasma in liquid nitrogen phase. Therefore, it is necessary to consider more useful and safe methods for freezing and storing various cells. In this study, we investigated the effects of temperature during long-term storage (8 years at -80 °C and in liquid nitrogen phase) on the quality of various cells (human hepatocellular carcinoma cells, bovine carotid artery normal endothelial cells, mouse fibroblast cells 3T3, and mouse embryo fibroblast cells STO). We examined the cell viability of cryopreserved human hepatocellular carcinoma cells at -80 °C using culture medium containing 10% DMSO, Cell Banker 1, and Cell Banker 2 as cryopreservation solutions. Among these solutions, Cell Banker 1 showed the highest efficiency. The viability of human hepatocellular carcinoma and bovine carotid artery normal endothelial cells in the Cell Banker 1 stored at -80 °C was over 90%, which was the same as that in liquid nitrogen phase. The cells stored at -80 °C had a morphology similar to that of the cells stored at liquid nitrogen phase. The proliferation of cells stored at -80 °C and in liquid nitrogen phase was not significantly different. Furthermore, none of the cells were infected with mycoplasma. There was no marked difference in the albumin secretion between the human hepatocellular carcinoma cells stored at -80 °C and those in liquid nitrogen phase. The short tandem repeats of the human hepatocellular carcinoma cells stored at -80 °C were identical to those stored in liquid nitrogen phase. In this report, various cells stored long-term at -80 °C were able to be used effectively after long-term storage. These findings can be applied to drug discovery, cell medicine, and cell therapy.

Although induced pluripotent stem (iPS) cells have significant implications for overcoming most of the ethical issues associated with embryonic stem cells, several issues related to the use of iPS cells in clinical applications remain unresolved, including the issue of teratoma formation. We previously reported that the induction of induced tissue-specific stem (iTS) cells from the pancreas (iTS-P) or liver (iTS-L) by the transient overexpression of reprogramming factors, combined with tissue-specific selection and the generation of iTS cells, could have important implications for the clinical application of stem cells. At the same time, we also generated "induced fibroblast-like (iF) cells" that were capable of self-renewal, which had a similar morphology to fibroblast cells. In this study, we evaluated iF cells. iF cells are unlikely to show adipogenic/osteogenic differentiation. Moreover, iF cells have the ability to form tumors and behave similarly to pancreatic cancer cells. The technology used in the generation of iPS/iTS cells is also associated with the risk of generating cancer-like cells.

In the United States, Alzheimer's disease (AD) is the most common cause of dementia, accompanied by substantial economic and emotional costs. During 2015, more than 15 million family members who provided care to AD patients had an estimated total cost of 221 billion dollars. Recent studies have shown that elevated total plasma levels of homocysteine (tHcy), a condition known as hyperhomocysteinemia (HHcy), is a risk factor for AD. HHcy is associated with cognitive decline, brain atrophy, and dementia; enhances the vulnerability of neurons to oxidative injury; and damages the blood-brain barrier. Many therapeutic supplements containing vitamin B12 and folate have been studied to help decrease tHcy to a certain degree. However, a therapeutic cocktail approach with 5-methyltetrahydrofolate, methyl B12, betaine, and N-acetylcysteine (NAC) have not been studied. This novel approach may help target multiple pathways simultaneously to decrease tHcy and its toxicity substantially.

Adipose-derived mesenchymal stem cells (ASCs) release factors beneficial for islets in vitro and protect against hyperglycemia in rodent models of diabetes. Oxygen tension has been shown to induce metabolic changes and alter ASCs' release of soluble factors. The effects of hypoxia on the antidiabetic properties of ASCs have not been explored. To investigate this, we incubated human ASCs for 48 h in 21% (normoxia) or 1% O₂ (hypoxia) and compared viability, cell growth, surface markers, differentiation capability, and soluble factors in the conditioned media (CM). Human islets were exposed to CM from ASCs incubated in either normoxia or hypoxia, and islet function and apoptosis after culture with or without proinflammatory cytokines were measured. To test hypoxic preconditioned ASCs' islet protective effects in vivo, ASCs were incubated for 48 h in normoxia or hypoxia before being injected into Balb/c Rag 1^-/- immunodeficient mice with streptozotocin-induced insulitis. Progression of diabetes and insulin content of pancreas were measured. We found that incubation in hypoxia was well tolerated by ASCs and that levels of VEGF-A, FGF-2, and bNGF were elevated in CM from ASCs incubated in hypoxia compared to normoxia, while levels of HGF, IL-8, and CXCL1 were reduced. CM from ASCs incubated in hypoxia significantly improved human islet function and reduced apoptosis after culture, and reduced cytokine-induced apoptosis. In our mouse model, pancreas insulin content was higher in both groups receiving ASCs compared to control, but the mice receiving preconditioned ASCs had lower random and fasting blood glucose, as well as improved oral glucose tolerance compared to untreated mice. In conclusion, our in vitro results indicate that the islet protective potential of ASCs improves in hypoxia, and we give insight into factors involved in this. Finally we show that hypoxic preconditioning potentiates ASCs' antidiabetic effect in vivo.

There is currently a dearth of treatment options for stroke or traumatic brain injury that can restore cognitive and motor function. Regenerative and translational medicine have ushered forth promising new methods for mediating recovery in the central nervous system, the most salient of which are rehabilitation and stem cell therapies that, when combined, result in more pronounced recovery than one approach alone.