© flickr & natashalcd
耳が聞こえるしくみで重要な役割を果たす細胞を，幹細胞と線維芽細胞をもとに作り出す方法が発見された。内耳にある有毛細胞と呼ばれる細胞には毛のような突起があり，空気の振動で突起が曲がり機械的な振動が生じると，これが電気化学的な信号として脳に伝わり，音として感じられる。人間には生まれた時に片耳あたり約3万個の有毛細胞があるが，その多くが失われると聴覚に障害が起こり，自然に増えることはないという。今回成功した方法で作られた有毛細胞は，耳に移植して難聴を治療するほか，治療薬の評価にも使えると考えられる。（吉田素子）
Deep inside the ear, specialized(1) cells(2) called hair cells(3) detect(4) vibrations(5) in the air and translate them into sound. Ten years ago, Stefan Heller, PhD(6), professor of otolaryngology(7) at the Stanford University School of Medicine, came up with(8) the idea that if you could create these cells in the laboratory(9) from stem cells(10), it would go a long way toward(11) helping scientists understand the molecular(12) basis of hearing in order to develop better treatments for deafness(13).
After years of lab work(14), researchers(15) in Heller’s lab(16) report in the May 14 issue of Cell that they have found a way to develop mouse(17) cells that look and act just like the animal’s inner-ear(18) hair cells -- the linchpin to(19) our sense of hearing and balance(20) -- in a petri dish(21).
If they can further perfect the recipe(22) to generate(23) hair cells in the millions, it could lead to(24) significant scientific and clinical advances along the path to(25) curing deafness in the future, they said.
“This gives us real hope that there might be some kind of therapy(26) for regenerating(27) hair cells,” said David Corey, PhD, professor of neurobiology(28) at Harvard University who was not involved in the study. “It could take a decade or more, but it’s a possibility.”
Using both embryonic stem cells(29) from mice as well as reprogrammed(30) mouse fibroblasts(31) (a type of relatively undifferentiated(32) cell found in many parts of the body), the researchers present a step-by-step(33) guide on how to coax(34) these cells into the sensory cells(35) that normally reside(36) in the inner ear.
(1) 特化した (2) 細胞 (3) 有毛細胞 (4) 検知する (5) 振動 (6) 博士 (7) 耳鼻咽喉学
(8) 思い付いた (9) 実験室 (10) 幹細胞 (11) ～に大きな役割を果たす (12) 分子の (13) 難聴 (14) 実験
(15) 研究者 (16) 研究室 (17) マウス (18) 内耳の (19) ～の要である (20) 聴覚と平衡感覚
(21) ペトリ皿 (22) 方法 (23) 作り出す (24) ～につながる (25) ～に向かって (26) 治療
(27) 再生すること (28) 神経生物学 (29) 胚性幹細胞 (30) （分化を）再プログラムされた
(31) 線維芽細胞 (32) 未分化の (33) 段階的な (34) 誘導する (35) 感覚細胞 (36) 存在する
