Anti-ADAM10 Monoclonal antibody, PE

The present study was designed to determine the effects of senescence and angiotensin II (Ang II) on expression and processing of amyloid precursor protein (APP) in human brain microvascular endothelial cells (BMECs). Senescence caused a decrease in APP expression thereby resulting in reduced secretion of soluble APP alpha (sAPP alpha). In contrast, beta-site APP cleaving enzyme (BACE1) expression and production of amyloid beta (A beta)40 were increased in senescent endothelium. Importantly, in senescent human BMECs, treatment with BACE1 inhibitor IV inhibited A beta generation and increased sAPP alpha production by enhancing a disintegrin and metalloprotease (ADAM) 10 expression. Furthermore, Ang II impaired expression of ADAM10 and significantly reduced generation of sAPP alpha in senescent human BMECs. This inhibitory effect of Ang II was prevented by treatment with BACE1 inhibitor IV. Our results suggest that impairment of alpha-processing and shift to amyloidogenic pathway of APP contribute to endothelial dysfunction induced by senescence. Loss of sAPPa in senescent cells treated with Ang II exacerbates detrimental effects of senescence on APP processing. Notably, inhibition of BACE1 has beneficial effects on senescence induced endothelial dysfunction. Reported findings may help to explain contributions of senescent cerebral microvascular endothelium to development of cerebral amyloid angiopathy and Alzheimer's disease (AD) pathology.

Background and AimThe multi-kinase inhibitor regorafenib (REG) was recently demonstrated to be effective in patients with sorafenib (SOR)-resistant hepatocellular carcinoma (HCC). Interestingly, SOR is known to enhance the accumulation of membrane-bound MHC class I polypeptide-related sequence A (mMICA) in HCC cells and to block the production of soluble MICA (sMICA), an immunological decoy. In addition, MICA is associated with HCC in patients with chronic hepatitis C. We have now compared the impact of REG and SOR on MICA in HCC cells, as well as the immunotherapeutic implications thereof. MethodsHepG2 and PLC/PRF/5 cells were exposed to REG and SOR, and levels of sMICA and mMICA were measured by ELISA and flow cytometry, respectively. The drugs were also tested in vitro for inhibitory activity against recombinant human A disintegrin and metalloprotease 9 (ADAM9), a sheddase that releases MICA from the membrane. ResultsTo a greater extent than SOR, but without marked difference in cytotoxicity, REG significantly suppressed mRNA and protein expression of ADAM9 and ADAM10, thereby decreasing production of sMICA and boosting accumulation of mMICA. Accumulation of mMICA in response to REG was reversed by siRNA against ADAM9. However, the drugs did not inhibit the enzymatic activity of ADAM9 in vitro. ConclusionsThe clinical superiority of REG over SOR is partially attributable to reduced MICA shedding via transcriptional suppression of ADAM9 and ADAM10.