P53 mediates the protective effects of metformin in inflamed lung endothelial cells

Ultrathin and handleable nanofibrous net as a novel biomimetic basement membrane material for endothelial barrier formation

Many strategies have been adopted to develop porous membranes to reconstitute basement membrane in vitro, which play a key role in the development of in vitro biomimetic models. However, the development of an artificial basement membrane combines cytocompatibility and nano-thickness is still challenging. Herein, a monolayer nanofibrous net patch was fabricated by combining microfabrication and electrospinning as a biomimetic basement membrane material, which was demonstrated for endothelial barrier formation. The nanofibrous net patches with different fiber densities were obtained by controlling electrospinning time. The net was with high porosity and ultrathin thickness approximate to the diameter of nanofibers, which is comparable to that of the native basement membrane. The morphology, proliferation and cell-cell/cell-substrate interactions of endothelial cells on the nanofibrous nets were studied and compared with track-etched polycarbonate membrane and traditional multilayer nanofibers membrane. In addition, the results of TEER measurement and permeability test demonstrated that the endothelial barrier formed on the nanofibrous net patch displayed stronger barrier integrity and function. Therefore, the proposed nanofibrous net patch shows great potential as a novel biomimetic basement membrane, which is promising to be applied for in vitro tissue mimetic applications.

Effects of TP53 Mutations and miRs on Immune Responses in the Tumor Microenvironment Important in Pancreatic Cancer Progression

Approximately 90% of pancreatic cancers are pancreatic ductal adenocarcinomas (PDAC). PDAC is the fourth leading cause of cancer death world-wide. Therapies for PDAC are largely ineffective due to the dense desmoplastic tumor microenvironment which prevents chemotherapeutic drugs and small molecule inhibitors from exerting effective anti-cancer effects. In this review, we will discuss the roles of TP53 and miRs on the PDAC tumor microenvironment and how loss of the normal functions of TP53 promote tumor progression. The TP53 gene is mutated in approximately 50% of pancreatic cancers. Often, these TP53 mutations are point mutations which confer additional functions for the TP53 proteins. These are called gain of function (GOF) mutations (mut). Another class of TP53 mutations are deletions which result in loss of the TP53 protein; these are referred to TP53-null mutations. We have organized this review into various components/properties of the PDAC microenvironment and how they may be altered in the presence of mutant TP53 and loss of certain miR expression.

Unfolded protein response in endothelial injury

Endothelial barrier dysfunction is associated with sepsis and lung injury, both direct and indirect. We discuss the involvement of unfolded protein response in the protective effects of heat shock protein 90 inhibitors and growth hormone releasing hormone antagonists in the vascular barrier, to reveal new possibilities in acute respiratory distress syndrome treatment.