Dong Li

Stem cells derived from adult tissues or from the inner cell mass of blastocyst-stage embryos can self-renew in culture and have the remarkable potential to undergo lineage-specific differentiation. Extensive studies have been devoted to achieving a better understanding of the soluble factors and the mechanism(s) by which they regulate the fate decisions of these cells, but it is only recently that a critical role has been revealed for physical and mechanical factors in controlling self-renewal and lineage specification. This review summarizes selected aspects of current work on stem cell mechanics with an emphasis on the influence of matrix stiffness, surface topography, cell shape and mechanical forces on the fate determination of mesenchymal stem cells and embryonic stem cells.

Directional induction and differentiation of mesenchymal stem cells (MSCs) is very important to clinical therapy, but the mechanisms that govern differentiation are not well understood. However, traditional plate culture cannot precisely control cellular behavior because cells take up substances while secreting cytokines and wastes. Here, we used a microfluidic device to culture MSCs inside a microchamber. Hepatic differentiation medium was perfused to evaluate the ability of MSCs to differentiate toward hepatic cells on the chip. Parallel differentiation on 96-well plates was used to provide a detailed comparison of the differences between the two culturing methods. After treatment for 4 weeks, differentiated cells from both groups could express hepatocyte-specific markers, including alpha-fetoprotein, tyrosine aminotransferase, and albumin. The bioactivity assays revealed that these hepatocyte-like cells could uptake lipoprotein, but cells that differentiated on the chip showed more positive signals than the cells cultured on plates. Our results indicated that a microfluidic platform might be a potential tool for cost-effective and automated cell culture, and have potential applications in reliable cell-based screens and assays.

Summary This study was conducted to establish pig embryonic stem (ES)-like cell lines from nuclear transfer blastocysts. A green fluorescent protein (GFP)-expressing cell line was used as the source of donor cells injected into the enucleated oocytes. Blastocysts were collected at D5 (the fifth day), D7 (the seventh day) and D9 (the ninth day). Differential staining was used to assay the viability and development of blastocysts from the 3 days. The number of inner cell mass (ICM) cells increased from 1.83 ± 0.8 (D5) to 5.37 ± 1.2 (D7) to 7.56 ± 1.5 (D9). The expression profiles of embryonic stem (ES) cell factors (OCT4, SOX2, KLF4 and c-MYC) correlated best with the undifferentiated ES state and were identified by qPCR. The expression of the four factors was increased from D5 to D7, whereas the expression decreased from D7 to D9. We tried to isolate ES-like cells from these embryos. However, ES-like cells from the D7 blastocysts grew slowly and expressed alkaline phosphatase. The cells from the D9 blastocysts grew rapidly but did not express alkaline phosphatase. ES-like cells were not isolated from the D5 blastocysts. These results show that the cells from the D7 embryos are pluripotent but grow slowly. The cells from the D9 embryos grow rapidly but start to lose pluripotency.

Xiaoxia Ding,1 Shisong Rong,2 Yu Wang,1 Dong Li,1 Liang Wen,1 Bo Zou,1 Dongxiao Zang,1 Kemi Feng,3 Yuanbo Liang,3 Fenghua Wang,4 Gang Zhai1 1Department of Ophthalmology, Fushun Eye Hospital, Fushun, Liaoning, People’s Republic of China; 2Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear, Boston, MA, USA; 3Department of Ophthalmology, the Affiliated Eye Hospital, School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou, Zhejiang, People’s Republic of China; 4Department of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Laboratory, Beijing, People’s Republic of ChinaCorrespondence: Gang Zhai, Fushun Eye Hospital, No. 1 Hupo Street, Xinfu District, Fushun, Liaoning, 113008, People’s Republic of China, Email fsgangzhai@163.comAim: To report the prevalence of depression and its association with vision-related quality of life and social support in a type 2 diabetes mellitus (T2DM) population.Methods: Patients were recruited from a community-based study, Fushun Diabetic Retinopathy Cohort Study (FS-DIRECT), conducted between July 2012 and May 2013 in China. Depression was assessed using the Centre for Epidemiological Studies Depression Scale (CES-D). Vision-related quality of life was evaluated using the Visual Function Questionnaire-25 (VFQ-25). Social support was captured with the Social Support Rating Scale (SSRS). Generalized linear models were used to estimate the individual and joint association of VFQ-25 composite score (VFQCS) and SSRS score (SSRSS) with depression.Results: A total of 1618 subjects (60.9% female) aged 61.69 ± 8.72 years in an urban district of Jiangjun Street, Fushun City, Liaoning province, Northeast China from July 2012 to May 2013 were recruited, of which, 23.36% (95% CI: 21.30– 25.42%) were identified with depression. Every 14.1 increase in VFQ-25 composite score decreased the risk of depression by half (OR = 0.5; 95% CI: 0.4– 0.6); with the elevation of 10.0 SSRS score the risk of depression decreased by 40% (OR = 0.6; 95% CI: 0.5– 0.7). Patients with the VFQCS less than 91.3 and SSRSS less than 38.0 had 5.9 times more risk of depression (OR = 5.9; 95% CI: 3.6– 9.7). Age (over 60 years) (OR = 0.6; 95% CI: 0.4– 0.9) and medical history of cardiovascular disease (OR = 1.7; 95% CI: 1.1– 2.5) were independently correlated with depression symptom.Conclusion: The prevalence of depression is high among patients with T2DM in urban district in northeast China. Vision-related quality of life and social support scores are significantly associated with depression. Measures should be taken to screen depressive symptoms in patients with type 2 diabetes patients. These patients need to be intervened with appropriate and effective treatment as early as possible. Meanwhile, behavioral health specialists should guide the patient to get and use social support sources effectively.Keywords: diabetic retinopathy, depression, quality of vision, Visual Function Questionnaire-25, Social Support Rating Scale

OBJECTIVES: A coculture microfluidic chip had been fabricated to investigate the dynamic process of bone marrow mesenchymal stem cells migrating to the pancreatic islets in vitro. METHODS: We fabricated a coculture microfluidic chip using standard procedures. On the chip, bone marrow mesenchymal stem cells and pancreatic islets were introduced respectively into two microchambers which could be connected by a traffic tunnel. Migration assay was performed along the tunnel, and the function of pancreatic islets was timely evaluated by analysis of insulin secretion in response to high-glucose-challenge. RESULTS: The results showed that some bioactive factors excreted by freshly isolated pancreatic islets could enhance the migrating rate of BM-MSCs. Besides, pancreatic islets also showed a better survival and function by coculturing with bone marrow mesenchymal stem cells. CONCLUSION: The results demonstrated that bone marrow mesenchymal stem cells had the ability to migrate to pancreatic islets and provide an apparent overall preservation for islet function. This microfluidic device was a potentially useful tool to mimic actual biological processes of bone marrow mesenchymal stem cells migrating to the pancreatic islets in vitro.