Optogenetic induction of hibernation-like state with modified human Opsin4 in mice.

We recently determined that the excitatory manipulation of Qrfp-expressing neurons in the preoptic area of the hypothalamus (quiescence-inducing neurons [Q neurons]) induced a hibernation-like hypothermic/hypometabolic state (QIH) in mice. To control the QIH with a higher time resolution, we develop an optogenetic method using modified human opsin4 (OPN4; also known as melanopsin), a G protein-coupled-receptor-type blue-light photoreceptor. C-terminally truncated OPN4 (OPN4dC) stably and reproducibly induces QIH for at least 24 h by illumination with low-power light (3 µW, 473 nm laser) with high temporal resolution. The high sensitivity of OPN4dC allows us to transcranially stimulate Q neurons with blue-light-emitting diodes and non-invasively induce the QIH. OPN4dC-mediated QIH recapitulates the kinetics of the physiological changes observed in natural hibernation, revealing that Q neurons concurrently contribute to thermoregulation and cardiovascular function. This optogenetic method may facilitate identification of the neural mechanisms underlying long-term dormancy states such as sleep, daily torpor, and hibernation.

Potent and broad anticancer activities of leaf extracts from Melia azedarach L. of the subtropical Okinawa islands.

Plant extracts have been traditionally used for various therapeutic applications. By conducting an initial screening of several subtropical plants, in this study, we evaluated the anticancer activities of Melia azedarach L. The extract from Melia azedarach L. leaves (MLE) show high cytotoxic effects on cancer cells and in vivo mouse and dog tumor models. During the initial screening, MLE showed strong antiproliferative activity against HT-29 colon, A549 lung, and MKN1 gastric cancer cells. In subsequent tests, using 39 human tumor cell lines, we confirmed the potent anticancer activities of MLE. The anticancer activity of MLE was also confirmed in vivo. MLE markedly inhibited the growth of transplanted gastric MKN1 cancer xenografts in mice. To elucidate the mechanism underlying the anticancer effects of MLE, MLE-treated MKN1 cells were observed using an electron microscope; MLE treatment induced autophagy. Furthermore, western blot analysis of proteins in lysates of MLE-treated cells revealed induction of light chain 3 (LC3)-II autophagosomal proteins. Thus, MLE appeared to suppress MKN1 cell proliferation by inducing autophagy. In addition, in the mouse macrophage cell line J774A.1, MLE treatment induced TNF-α production, which might play a role in tumor growth suppression in vivo. We also performed a preclinical evaluation of MLE treatment on dogs with various cancers in veterinary hospitals. Dogs with various types of cancers showed a mean recovery of 76% when treated with MLE. Finally, we tried to identify the active substances present in MLE. All the active fractions obtained by reverse-phase chromatography contained azedarachin B-related moieties, such as 3-deacetyl-12-hydroxy-amoorastatin, 12-hydroxy-amoorastatin, and 12-hydroxyamoorastaton. In conclusion, MLE contains substances with promising anticancer effects, suggesting their future use as safe and effective anticancer agents.