The establishment of a tree shrew model for systemic lupus erythematosus (SLE) provides a new method to evaluate the pathogenesis of autoimmune diseases. Eighty tree shrews were randomly divided into four groups receiving either an intraperitoneal injection of pristane, lipopolysaccharide (LPS), or pristane and LPS, or no injection. Three weeks after injection, the SLE model tree shrews were divided into the model group and the treatment group. Tree shrews in the treatment group and the normal control group were infused with umbilical cord mesenchymal stem cells (UC-MSCs). The cells were labeled with DiR. Two weeks after transplantation, three groups of tree shrews were analyzed for urine protein, serum antinuclear antibodies and antiphospholipid, and inflammatory cytokine antibody microarray detection. The heart, liver, spleen, lung, and kidney were collected from the three groups and subjected to hematoxylin and eosin (HE) staining and detection of renal immune complex deposition. HE staining indicated pathology in the model group. Red fluorescence revealed immune complex deposition in the kidneys from the model group. The combined intraperitoneal injection of pristane and LPS is the best way to induce SLE pathological changes. The pathological changes improved after UC-MSC treatment.

Recent epigenetic studies have revealed a strong association between DNA methylation and aging and lifespan, which changes (increases or decreases) with age. Based on these, the construction of age prediction models associated with DNA methylation levels can be used to infer biological ages closer to the functional state of the organism. We downloaded methylation data from the Gene Expression Omnibus (GEO) public database for normal peripheral blood samples from people of different ages. We grouped the samples according to age (18-35 years and >50 years), screened the methylation sites that differed between the two groups, identified 44 differentially methylated sites, and subsequently obtained 11 age-related characteristic methylation sites using the random forest method. Then, we constructed an age classification model with these 11 characteristic methylation sites using an artificial neural network and evaluated its efficacy. The age classification model was constructed by an artificial neural network and its efficacy was evaluated. The model predicted an area under the curve (AUC) of 0.97 in the validation set and accurately distinguished between those aged 18-35 and >50 years. Furthermore, the levels of these 11 characteristic methylation sites also differed significantly between the two sets of samples in the validation set, including six newly identified age-related methylation sites (P<0.001). Finally, we constructed a multifactor regulatory network based on the corresponding genes of age-related methylation sites to reveal the transcriptional and post-transcriptional regulation patterns. As a result of the increasing problem of aging, the age classification model we constructed allows us to accurately distinguish different age groups at the molecular level, which will be more predictive than chronological age for assessing individual aging and future health status.

Background: Umbilical cord mesenchymal stem cell transplantation can treat metabolic syndrome, but the tracing of cells in the body after transplantation has always been a problem. Tree shrew umbilical cord mesenchymal stem cells were labeled with the dark red fluorescent dye DIR and a metabolic syndrome model in tree shrew was generated. The migration, distribution, colonization and survival of the cells were observed. Methods: Tree shrew umbilical cord mesenchymal stem cells were labeled with the dark red fluorescent dye DIR. Three days after the tree shrew model was generated, the pancreas, kidney and liver were placed in a small animal live imager to observe the distribution of the labeled cells. Result: The labeled cells showed deep red fluorescence in the live imager. After treatment with the transplanted cells, dark red fluorescent signals were observed in the liver, kidney and pancreas of the tree shrews but not in the untreated group and no dark red fluorescent signal was observed in the cell distribution.

Background: Protein extracts from chicken egg whites were prepared by utilizing different solvents and we studied the differences in proliferation. Methods: The egg white extract was prepared by using lysate, phosphate-buffered saline (PBS), saline and pure water. The in vitro mixture experiment was carried out to observe the effect of different egg white preparations on the proliferation of cells. The samples were divided into the following groups: the control group with media, the original lysate group, the new lysate group, the PBS group, the saline group and the pure water group. Result: The study found that at final concentrations of 10%, 20%, 30%, 40% and 50%, the differences among the six groups were statistically significant (P less than 0.01, F greater than 100). The results of pairwise comparison showed that the proliferative effect of chicken egg albumin extract prepared by PBS was significantly higher than that of the medium at final concentrations of 20%, 30% and 50% (P less than 0.05). When the fetal bovine serum concentration was only 8%, 7% and 5%, the cell proliferation effect was better than that of the control group with 10% fetal bovine serum, indicating that the chicken egg white extract promoted cell proliferation. This result indicated that the best chicken egg albumin extract was obtained through PBS addition. The quantity of expensive fetal bovine serum could be considerably reduced by supplementing the media with chicken egg albumin extract. Among the solvents tested, PBS was the best solvent for preparing chicken egg albumin extract.

Background: Stem cell protein chips can detect stem cell-associated proteins expressed in cells. Methods: We isolated and cultured rabbit peripheral blood mononuclear cells (R-PBMCs) in two bottles, one containing medium and one containing medium with 40% chicken egg white extract. Similarly, 293T cells were also divided into two vials: one vial contained medium and one vial contained medium with 40% chicken egg white extract. After 3 days of culture, proteins were extracted from the cells and used for the stem cell protein chip. Result: Protein chip detection showed that 10 stem cell-associated proteins were increased in the rabbit peripheral blood mononuclear cells induced by chicken egg white extract. There were also 4 stem cell-associated proteins increased in the 293T cells induced by chicken egg white extract. The results of KEGG enrichment analysis indicated that peripheral blood mononuclear cells of rabbits were involved in the regulation of stem cell pluripotency before and after induction. Moreover, 293T cells were involved in the regulation of stem cell pluripotency before and after induction.