Résumé
Activation of the heart normally begins in the sinoatrial node (SAN). Electrical impulses spontaneously released by SAN pacemaker cells (SANPCs) trigger the contraction of the heart. However, the cellular nature of SANPCs remains controversial. Here, we report that SANPCs exhibit glutamatergic neuron-like properties. By comparing the single-cell transcriptome of SANPCs with that of cells from primary visual cortex in mouse, we found that SANPCs co-clustered with cortical neurons. Tissue and cellular imaging confirmed that SANPCs contained key elements of glutamatergic neurotransmitter system, expressing genes encoding glutamate synthesis pathway (Gls), ionotropic and metabotropic glutamate receptors (Grina, Gria3, Grm1 and Grm5), and glutamate transporters (Slc17a7). SANPCs highly expressed cell markers of glutamatergic neurons (Snap25 and Slc17a7), whereas Gad1, a marker of GABAergic neurons, was negative. Functional studies revealed that inhibition of glutamate receptors or transporters reduced spontaneous pacing frequency of isolated SAN tissues and spontaneous Ca
Résumé
Objective To explore the mechanism that gold nanorods trigger apoptosis in cancer cells.Methods Gold nanorods was synthesized by gold seed growing method, and its characterization was detected; gold nanorods on cell proliferation-toxicity were evaluated by CCK-8 Kit and apoptosis were detected by flow; mitochondrial membrane potential were tested by JC-1 and activation of Caspase 9 and Caspase 3 were detected by western blot. Results The results found that gold nanorods had nontoxic to normal cells, but highly toxic to tumor cells; and with the increasing of gold nanorods’ working time, the percentage of apoptotic cancer cells was increasing; in addition to, normal cells’ mitochondrial membrane potential did not change, but cancer cells had a significant reduction in mitochondrial membrane potential.Conclusion This study proves that gold nanorods induce apoptosis through the mitochondrial apoptosis pathway.