In the advance, online edition of Science this week, an international research team reports that the "genetic reactivation of cone photoreceptors restores visual responses in retinitis pigmentosa." Using mouse models of retinitis pigmentosa, the team found that the "expression of archaebacterial halorhodopsin in light-sensitive cones can substitute for the native phototransduction cascade and restore their light sensitivity." Then, by using human ex vivo retinas, the authors showed that halorhodopsin can also reactivate light-insensitive human photoreceptors.
In Science Translational Medicine this week, investigators at the Children's Hospital of Pittsburgh, the Sloan-Kettering Institute for Cancer Research, and the National Human Genome Research Institute report the role of WAS protein in Human Wiskott-Aldrich syndrome pathogeneis. WASp affects that transcriptional regulation of TBX21, which regulates TH1, they show, adding that "genome-wide mapping demonstrates association of WASp in vivo with the gene-regulatory network that orchestrates TH1 cell fate choice in the human TH cell genome." The authors suggest that their findings imply a previously unknown role for WASp as an epigenetic modifier.
Researchers at the National Cancer Institute show that "Nodal signaling recruits the histone demethylase Jmjd3 to counteract polycomb-mediated repression at target genes" in Science Signaling this week. They demonstrate that a key function of the Nodal-Smads2/3 pathway is to guide Jmjd3 to target genes, "thereby counteracting repression by Polycomb." Jmjd3 knockdown alone, the authors write, "substantially reduced Nodal target gene expression, whereas in the absence of Polycomb, target loci were expressed independently of Nodal signaling."
And in this week's issue of Science, a multidisciplinary team from Harvard describes their "biomimetic microsystem that reconstitutes the critical functional alveolar-capillary interface of the human lung," or, lung-on-a-chip device. Dongeun Huh et al. suggest that micro-devices that reconstitute tissue-tissue interfaces, such as theirs, may "expand the capabilities of cell culture models and provide low-cost alternatives to animal and clinical studies for drug screening and toxicology applications."