Biosensor incorporating cell barrier architectures for detecting Staphylococcus aureus alpha toxin

ADAM10 mediates vascular injury induced by Staphylococcus aureus α-hemolysin

Staphylococcus aureus is a leading cause of bacteremia and sepsis. The interaction of S. aureus with the endothelium is central to bloodstream infection pathophysiology yet remains ill-understood. We show herein that staphylococcal α-hemolysin, a pore-forming cytotoxin, is required for full virulence in a murine sepsis model. The α-hemolysin binding to its receptor A-disintegrin and metalloprotease 10 (ADAM10) upregulates the receptor's metalloprotease activity on endothelial cells, causing vascular endothelial-cadherin cleavage and concomitant loss of endothelial barrier function. These cellular injuries and sepsis severity can be mitigated by ADAM10 inhibition. This study therefore provides mechanistic insight into toxin-mediated endothelial injury and suggests new therapeutic approaches for staphylococcal sepsis.

Biosensor incorporating cell barrier architectures on ion selective electrodes for early screening of cancer

Angiogenesis occurs during the early phase of cancer. Recruitment of new blood vessels by existing cancer cells leads to the release of higher concentrations of cytokines as compared to cells in healthy individuals. Some of the common cytokines observed at higher concentrations, such as vascular endothelial growth factor, basic fibroblast growth factor, hepatocyte growth factor and tumor necrosis factor-alpha, are also known to induce increased permeability across an endothelial cell monolayer. A whole-cell-based biosensor has been developed that can detect the presence of small quantities of the abovementioned cytokines individually and in different combinations. It was observed that the biosensor could differentiate between the cytokine concentrations observed in the sera of healthy individuals and cancer patients. The biosensor was also evaluated by exposing it to actual serum. These results demonstrated that the sensor can distinguish between healthy individuals and cancer patients and that the corresponding biosensor responses correlate with the stages of cancer.