Anti-MAPK1 (N-terminal) polyclonal antibody

Human mesenchymal stem cells (hMSCs) receive differentiation cues from a number of stimuli, including extracellular matrix (ECM) stiffness. The pathways used to sense stiffness and other physical cues are just now being understood and include proteins within focal adhesions. To rapidly advance the pace of discovery for novel mechanosensitive proteins, we employed a combination of in silico and high throughput in vitro methods to analyze 47 different focal adhesion proteins for cryptic kinase binding sites. High content imaging of hMSCs treated with small interfering RNAs for the top 6 candidate proteins showed novel effects on both osteogenic and myogenic differentiation; Vinculin and SORBS1 were necessary for stiffness-mediated myogenic and osteogenic differentiation, respectively. Both of these proteins bound to MAPK1 (also known as ERK2), suggesting that it plays a context-specific role in mechanosensing for each lineage; validation for these sites was performed. This high throughput system, while specifically built to analyze stiffness-mediated stem cell differentiation, can be expanded to other physical cues to more broadly assess mechanical signaling and increase the pace of sensor discovery.

OBJECTIVE: To elucidate the role of morphine in inducing apoptosis of mouse hippocampal neurons HT-22 by upregulating microRNA-181-5p (miR-181-5p). MATERIALS AND METHODS: After treatment of different doses of morphine, changes in proliferative ability, apoptosis, and expression levels of miR-181-5p and MAPK1 in HT-22 cells were assessed through a series of functional experiments. Regulatory effects of miR-181-5p on morphine-induced phenotype changes of HT-22 cells were examined. The interaction between miR-181-5p and MAPK1, and their involvement in morphine-induced neuron apoptosis were explored by Luciferase assay and rescue experiments, respectively. RESULTS: Morphine treatment markedly attenuated viability and proliferative ability in HT22 cells, while apoptotic rate increased. MiR-181-5p was upregulated and MAPK1 was down regulated in HT-22 cells by morphine induction. Knockdown of miR-181-5p enhanced viability and proliferative ability, as well as reduced apoptosis in morphine-induced HT-22 cells. MiR-181-5p could specifically bind MAPK1 and negatively regulate its expression level. Knockdown of MAPK1 was able to reverse the regulatory effects of miR-181-5p on morphine-induced phenotype changes of HT-22 cells. CONCLUSIONS: Morphine induces apoptosis of hippocampal neurons HT-22 by upregulating miR-181-5p to suppress the level of MAPK1.