1,3-Dinitrobenzene neurotoxicity - Passage effect in immortalized astrocytes

A Personalized Glomerulus Chip Engineered from Stem Cell-Derived Epithelium and Vascular Endothelium

Progress in understanding kidney disease mechanisms and the development of targeted therapeutics have been limited by the lack of functional in vitro models that can closely recapitulate human physiological responses. Organ Chip (or organ-on-a-chip) microfluidic devices provide unique opportunities to overcome some of these challenges given their ability to model the structure and function of tissues and organs in vitro. Previously established organ chip models typically consist of heterogenous cell populations sourced from multiple donors, limiting their applications in patient-specific disease modeling and personalized medicine. In this study, we engineered a personalized glomerulus chip system reconstituted from human induced pluripotent stem (iPS) cell-derived vascular endothelial cells (ECs) and podocytes from a single patient. Our stem cell-derived kidney glomerulus chip successfully mimics the structure and some essential functions of the glomerular filtration barrier. We further modeled glomerular injury in our tissue chips by administering a clinically relevant dose of the chemotherapy drug Adriamycin. The drug disrupts the structural integrity of the endothelium and the podocyte tissue layers, leading to significant albuminuria as observed in patients with glomerulopathies. We anticipate that the personalized glomerulus chip model established in this report could help advance future studies of kidney disease mechanisms and the discovery of personalized therapies. Given the remarkable ability of human iPS cells to differentiate into almost any cell type, this work also provides a blueprint for the establishment of more personalized organ chip and 'body-on-a-chip' models in the future.

Evaluation of cytotoxicity of propofol and its related mechanism in glioblastoma cells and astrocytes

Propofol (2,6-diisopropylphenol), one of the extensively and commonly used anesthetic agents, has been shown to affect the biological behavior of various models. Previous researches have shown that propofol-induced cytotoxicity might cause anticancer effect in different cells. However, the mechanisms underlying the effect of propofol on cytotoxicity is still elusive in human glioblastoma cells. The aims of this study were to evaluate effects of propofol on cytotoxicity, cell cycle distribution and ROS production, and establish the relationship between oxidative stress and cytotoxicity in GBM 8401 human glioblastoma cells and DI TNC1 rat astrocytes. Propofol (20-30 μM) concentration-dependently induced cytotoxicity, cell cycle arrest, and increased ROS production in GBM 8401 cells but not in DI TNC1 cells. In GBM 8401 cells, propofol induced G2/M phase cell arrest, which affected the CDK1, cyclin B1, p53, and p21 protein expression levels. Furthermore, propofol induced oxygen stresses by increasing O2- and H₂ O₂ levels but treatment with the antioxidant N-acetylcysteine (NAC) partially reversed propofol-regulated antioxidative enzyme levels (superoxide dismutase, catalase, and glutathione peroxidase). Most significantly, propofol induced apoptotic effects by decreasing Bcl-2 but increasing Bax, cleaved caspase-9/caspase-3 levels, which were partially reversed by NAC. Moreover, the pancaspase inhibitor Z-VAD-FMK also partially prevented propofol-induced apoptosis. Together, in GBM 8401 cells but not in DI TNC1 cells, propofol activated ROS-associated apoptosis that involved cell cycle arrest and caspase activation. These findings indicate that propofol not only can be an anesthetic agent which reduces pain but also has the potential to be used for the treatment of human glioblastoma.

Susceptibility of neuroblastoma cells to rabies virus may be affected by passage number

Maintaining a healthy, continuous immortalized cell line is essential for rabies laboratories that perform virus isolation assays and test for the presence of viral neutralizing antibodies. Individuals who routinely work with rabies virus, such as rabies laboratory employees, or those who may have a high potential for exposure to rabies virus, including veterinarians, should be tested for the presence of anti-rabies viral neutralizing antibodies (VNA) every 6-24 months, depending on potential exposure level. The gold standard for serum neutralization assays require the use of live rabies virus and cells that are sensitive to rabies virus infection. Additionally, virus isolation assays are routinely performed in rabies laboratories as a back-up for the direct fluorescent antibody test (dFAT). Currently there are no guidelines or publications recommending the use of low, intermediate, or high passage cell lines in rabies assays. In this study, we compared the sensitivity of intermediate, high, and extremely high passaged neuroblastomas to rabies virus using virus isolation, serum neutralization, and real time RT-PCR techniques. Additionally, cells were examined microscopically to determine changes in morphology and dissemination of rabies virus antigen between intermediate, high, and extremely high passage cells. No significant difference was found between cell passage numbers and viral susceptibility between intermediate and high passaged cells. However, extremely high passaged cells (≥1200 passages) were less susceptible to viral infection and/or produced less virus following inoculation. As a result, rabies laboratories that use viral isolation and serum neutralization assays should regularly assess cell susceptibility to ensure the integrity and repeatability of the test.