Hepatic progenitor cell activation is induced by the depletion of the gut microbiome in mice.

The homeostasis of the gut microbiome is crucial for human health and for liver function. However, it has not been established whether the gut microbiome influence hepatic progenitor cells (HPCs). HPCs are capable of self-renewal and differentiate into hepatocytes and cholangiocytes; however, HPCs are normally quiescent and are rare in adults. After sustained liver damage, a ductular reaction occurs, and the number of HPCs is substantially increased. Here, we administered five broad-spectrum antibiotics for 14 days to deplete the gut microbiomes of male C57BL/6 mice, and we measured the plasma aminotransferases and other biochemical indices. The expression levels of two HPC markers, SRY-related high mobility group-box gene 9 (Sox9) and cytokeratin (CK), were also measured. The plasma aminotransferase activities were not affected, but the triglyceride, lactate dehydrogenase, low-density lipoprotein, and high-density lipoprotein concentrations were significantly altered; this suggests that liver function is affected by the composition of the gut microbiome. The mRNA expression of Sox9 was significantly higher in the treated mice than it was in the control mice (p < 0.0001), and a substantial expression of Sox9 and CK was observed around the bile ducts. The mRNA expression levels of proinflammatory factors (interleukin [IL]-1ß, IL-6, tumor necrosis factor [TNF]-α, and TNF-like weak inducer of apoptosis [Tweak]) were also significantly higher in the antibiotic-treated mice than the levels in the control mice. These data imply that the depletion of the gut microbiome leads to liver damage, negatively impacts the hepatic metabolism and function, and activates HPCs. However, the underlying mechanisms remain to be determined.

Human Clinical-Grade Parthenogenetic ESC-Derived Dopaminergic Neurons Recover Locomotive Defects of Nonhuman Primate Models of Parkinson's Disease.

Clinical application of stem cell derivatives requires clinical-grade cells and sufficient preclinical proof of safety and efficacy, preferably in primates. We previously successfully established a clinical-grade human parthenogenetic embryonic stem cell (hPESC) line, but the suitability of its subtype-specific progenies for therapy is not clear. Here, we compared the function of clinical-grade hPESC-derived midbrain dopaminergic (DA) neurons in two canonical protocols in a primate Parkinson's disease (PD) model. We found that the grafts did not form tumors and produced variable but apparent behavioral improvement for at least 24 months in most monkeys in both groups. In addition, a slight DA increase in the striatum correlates with significant functional improvement. These results demonstrated that clinical-grade hPESCs can serve as a reliable source of cells for PD treatment. Our proof-of-concept findings provide preclinical data for China's first ESC-based phase I/IIa clinical study of PD (ClinicalTrials.gov number NCT03119636).

Accreditation of Biosafe Clinical-Grade Human Embryonic Stem Cells According to Chinese Regulations.

Human embryonic stem cells (hESCs) are promising in regenerative medicine. Although several hESC-based clinical trials are under way, a widely accepted standard of clinical-grade cells remains obscure. To attain a completely xeno-free clinical-grade cell line, the system must be free of xenogenic components, the cells must have a comprehensive set of functions, and good manufacturing practice conditions must be used. In this study, following these criteria, we successfully derived two hESC lines, which were thereby considered "clinical-grade embryonic stem cells". In addition to the primary capacity for pluripotency, these two cell lines were efficiently differentiated into various types of clinical-grade progeny. Importantly, the cells were recognized by the National Institutes for Food and Drug Control of China for further eligible accreditation. These data indicate that we have established completely xeno-free clinical-grade hESC lines and their derivatives, which will be valuable for the foundation of an international standard for clinical-grade cells for therapy.

Effect of REAu on Silver Staining Results and Their UV-Vis Absorption Spectra.

La, Ce, Nd, Sm, Eu, Gd, Dy particles and gold nanoparticles were prepared. Effects of La-Au, Ce-Au, Nd-Au, Sm-Au, Eu-Au, Gd-Au and Dy-Au particles on silver staining results were studied, respectively, and UV-Vis absorption spectra of La-Au, Ce-Au, Nd-Au, Sm-Au, Eu-Au, Gd-Au and Dy-Au particles were studied. Times and colors of sports with La-Au, Ce-Au, Nd-Au, Sm-Au, Eu-Au, Gd-Au, Dy-Au particles are longer and darker than that of with gold nanoparticles, respectively. The time of sport with Nd-Au particles is as long as 30 min, which is 2.7 times as long as with gold nanoparticles. Although amount of gold nanoparticles reduced 80%, the color of sport with Nd-Au particles is darker than that of with gold nanoparticles. In 200.00-800.00 nm, La, Ce, Nd, Sm, Eu, Gd, Dy particles and gold nanoparticles has one absorption peak, respectively, and λ(max) is 275, 277, 276, 276, 278, 277, 278 and 521 nm, respectively. La-Au, Ce-Au, Nd-Au, Sm-Au, Eu-Au, Gd-Au, Dy-Au particles have two absorption peaks, respectively, λ(max)(RE) and λ(max) are 276 and 522 nm, 276 and 522 nm, 276 and 523 nm, 276 and 523 nm, 276 and 522 nm, 276 and 522 nm, 276 and 523 nm, respectively. λ(max) of Au nanoparticles and La particles occurs red moving respectively, and λ(max) of Ce, Eu, Gd and Dy particles occurs blue moving, respectively, and λ(max) of Nd and Sm particles is constant respectively. Rare earths particles and gold nanoparticles may have interaction, respectively.

[Different types of feeder cells for maintenance of human embryonic stem cells].

OBJECTIVE: To compare the effects of different types of feeder cells on supporting undifferentiation and high proliferation of human embryonic stem cells (hESC). METHODS: hESC were seeded on mouse embryonic fibroblasts (MEF), human marrow stromal cells (hMSC), and human foreskin fibroblasts (hFF), respectively. Colony number, cell quantity after digestion, and survival rate were observed by alkaline phosphatase (AP) staining and Trypan blue, and the biological properties of hESC after 5 passages were observed by immunofluorescence staining. RESULTS: Although all the three feeder layers could support the formation of hESC colonies and maintain pluripotency, the morphology of colonies on different feeder layers remarkably varied. The stage-specific embryonic antigen-3 and AP staining were positive on three types of feeders. The number of colonies, number of cells produced, and cell survival rates were significantly higher on MEF than on human feeder cells (P < 0.01). Furthermore, the number of AP-positive colonies and cell quantity were also significantly higher on hMSC than on hFF (P < 0.01). CONCLUSIONS: All three types of feeder cells are able to support the growth of hMSC, although MEF are more favourable for the proliferation. Two types of human feeder cells lay the foundation for the removal of animal-derived hESC culture system. hMSC is superior to hFF in supporting the proliferation of hESC.

The tropism of embryoid body cells for glioma cells.

It has been demonstrated that several types of adult stem cells have a common attribute of tropism for gliomas. In our study, we provided evidence that embryonic stem cell-derived embryoid body (EB) cells also exhibited a tropism for gliomas. Chemotaxis assays and organotypic hippocampal slice culture experiments showed that EB cells were attracted by the conditioned medium from C6 glioma cells and by C6 glioma cells deposited on the slice. Aggregate culture assays showed that EB cells could coaggregate with C6 glioma cells. Embryoid body cells injected intratumorally were found to distribute throughout the tumor mass. All data indicated that EB cells displayed a tropism for gliomas.