March 13, 2015

Induced Pluripotent Stem (iPS) Cells as a Potential Treatment for Type 1 Diabetes

Mary Frances Stinson '15

Type 1 diabetes is a chronic condition in which the pancreas does not produce insulin, a hormone that is necessary for the regulation of blood glucose, and allows our bodies to use glucose for energy or store it for later use. The American Diabetes Association estimates that in 2012, type 1 diabetes affects more than 1.25 million American adults and children. With this in mind, Raikwar and colleagues set out to create insulin producing cells (IPCs) from induced pluripotent stem (iPS) cells, in the hopes of developing a potential future treatment for type 1 diabetes. iPS cells are adult cells that have been reprogrammed to an embryonic stem cell-like state, and are then able to differentiate into multiple different types of cells. This extensive experiment included creating IPC cells from iPS cells (generated from adult human cells), verifying their pancreatic nature, and transplanting them into mice that were given a streptozotocin treatment, killing all the insulin producing (β-cells) in the pancreas. They monitored glucose levels for 150 days, and performed a glucose tolerance test on day 100. They also discovered, via non-invasive MRI, that the transplanted iPS cells formed a vascularized organoid on the surface of the kidney that secreted both insulin and glucagon and did effectively regulate blood glucose in diabetic mice. Unfortunately, although the cells did respond to glucose, the freshly differentiated IPCs poorly secreted insulin, most likely due to their immaturity. Researchers aim to improve protocol to address the issue of cellular maturity and bihormonal secretion. This research shows evidence that a pancreatic organ can be created in vivo and that iPS cells might be a novel option for the treatment of chronic diseases like type 1 diabetes.

Under Fire: The Effects of Electronic Cigarette Liquid on Human Airway Epithelial Cells

Sophia Salmanpour '15

2014 marked the 50th anniversary of the first report on smoking and health by the Surgeon General of the United States. Since this historic report, many of the health effects associated with cigarette smoking have become well known to the general public. Much less information is available on the long-term health impacts of the newly-introduced electronic cigarette. Brought to the U.S. market in 2006, electronic cigarettes (e-cigarettes) have become extremely popular and are largely advertised as smoking cessation tools with low-risk for smoking-related health impacts. The purpose of the study, Electronic cigarette liquid increases inflammation and virus infection in primary human airway epithelial cells, was to examine the effects of e-cigarette liquid (e-liquid) on pro-inflammatory cytokine (IL-6) production, HRV infection, and host defense molecules (SPLUNC1) in primary human airway epithelial cells from young, healthy non-smokers (Wu et al., 2014). My presentation of this paper focuses on the effects of e-liquid on IL-6 production and human rhinovirus (HRV) infection. Normal human tracheobronchial epithelial (hTBE) cells were isolated from donors (8-10 years old), digested, and then treated with one of 3 treatments: medium (control), various concentrations of e-liquid with 18 mg/ml of nicotine, and e-liquid with no nicotine; these cells were then infected with HRV-16. Cells exposed to tobacco-flavored e-liquid had significantly higher levels of HRV load than unexposed cells at both 6 and 24 hours. Furthermore, both e-liquid with and without nicotine had significantly increased levels of HRV-induced IL-6 production. The results of this study demonstrated that even short-term e-liquid exposure has the potential to harm airway cells in young, human subjects.

Effects of Napping on the Immune System after Sleep Deprivation

Kristin Berry '15

Chronic sleep restriction can cause serious issues to human health, not only with cognitive impairment and daytime sleepiness, but also it can cause an imbalance in metabolic, hormonal and immune homeostasis. It has been proven that napping can change the effects brought on by sleep restriction by restoring Norepinephrine and Interleukin-6 levels in the body, which are important biomarkers for immune function and neuronendocrine responses. Within the paper by Faraut et al., researchers were able to conduct a laboratory-based study that compared participants that were restricted to a night of sleep of two hours followed by a day without naps to participants that were allowed two thirty minute naps the day following the sleep restricted night. After a sleep restricted night, norepinephrine levels of those without a nap were found to be increased by the afternoon of the following day. However, when naps occurred, levels were normalized compared to the control. This was found to be statistically significant using a two-way repeated measure ANOVA (p-value=0.03). On the other hand, Interleukin-6 levels decreased by the afternoon the following day after a night of sleep deprivation in participants without a nap. However, the changes were normalized in participants that were able to nap the following day in comparison to the control (p-value=0.02). The data further suggests that napping has stress-releasing and positive immune effects. Napping could be easily applied in real settings as a countermeasure to the detrimental health consequences of sleep debt.