Yang, J.の論文のハイライト解説があるわね。
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Highlights
LIF promotes induction of pluripotency independent of its role in self-renewal
Increased Jak/Stat3 activation is sufficient to convert EpiSCs to naive pluripotency
Jak/Stat3 activation is a limiting factor in somatic cell reprogramming
Jak/Stat3 facilitates progression of intermediate states to pluripotency
いいわよ。時間はたっぷりあって急ぐことは何もない。何度でも貼り付けるわよ。
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However, as Fgf4-induced stem cells lay between STAP stem cells and trophoblast stem cells in the dendrogram, the possibility of contamination of STAP stem cells in the Fgf4-induced stem-cell population cannot be ruled out. Previous studies have indicated that inner cell mass (ICM)-type pluripotent cells can be removed from culture by treating the culture with a JAK inhibitor <16>(Extended Data Fig. 5a, b). In contrast, the JAK inhibitor treatment had no substantial effect on Oct4-GFP expression in Fgf4-induced stem-cell culture (Extended Data Fig. 5c, d; see Extended Data Fig. 5e, f for control). Expression of neither pluripotency markers (Fig. 2j) nor trophoblast markers (Fig. 2k) was substantially affected, indicating that pluripotency marker expression is unlikely to reflect contaminating STAP stem cells (ICM-type). Consistent with this idea, Fgf4-induced stem cells that were strongly positive for the trophoblast marker Itga7 (a surface marker for trophoblasts but not ES cells) also expressed high levels of Oct4-GFP (Extended Data Fig. 5g).
the possibility of contamination of STAP stem cells in the Fgf4-induced stem-cell population って
FI幹細胞の培養中にSTAP幹細胞が入った可能性を言ってるんでしょ。FI幹細胞の元はSTAP細胞だよね。STAP細胞を
FGF4培地に入れているところにSTAP幹細胞が入ったからといって、何がどうだというのかな。
なんだと言われてもねえ。レター論文には、<Previous studies have indicated
that inner cell mass (ICM)-type pluripotent cells can be removed from
culture by treating the culture with a JAK inhibitor <16>(Extended Data Fig. 5a, b).
とあるんだけど、肝心の元論部にそんなことが書いてあるかなあ。<16>はYang, J. et al.よね。
元論文の要旨は以下よね。
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LIF promotes induction of pluripotency independent of its role in self-renewal
Increased Jak/Stat3 activation is sufficient to convert EpiSCs to naive pluripotency
Jak/Stat3 activation is a limiting factor in somatic cell reprogramming
Jak/Stat3 facilitates progression of intermediate states to pluripotency
①LIFは自己複製におけるその役割とは別に多能性の誘導を促進する
②Jak / Stat3活性の増加だけでEpiSCをナイーブ型多能性に変換するに十分である
③Jak / Stat3活性は体細胞リプログラミングの制限因子である
④Jak / Stat3は多能性の中間状態の進行を促進する
Yang, J. et al.に関する筆者の誤解が根底にあるということだね。
<Previous studies have indicated that inner cell mass (ICM)-type pluripotent
cells can be removed from culture by treating the culture with a JAK inhibitor <16>
(Extended Data Fig. 5a, b).>の<inner cell mass (ICM)-type pluripotent cells>って
どこに書いてあるか。論文にはEpiSCsと書かれている。
笹井さんくさいね。論文を通さないといけない。レター論文は外さずにネイチャ再投稿と
決まっている。この何が何だかわからない実験結果を何とか取りまとめなければならなかった。
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Thus, our findings indicate that epigenetic fate determination of mammalian cells can be markedly converted in a context-dependent manner by strong environmental cues.
語彙選択ってそのとき読んでいた文章に影響されたりするよねえ。cuesって別に特段
どうってことない語彙なんだろうけどね。Yang, J. et al.の文章にそういう表現が
出てくると何か考えてたのかなあとふと思ってしまうけどな。
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This reprogramming is completely suppressed if cells are maintained in activin and Fgf, demonstrating the dominant influence of extrinsic cues.
我々は昨日こう書いた。
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77： 開高健 ：2019/02/28(木) 18:00:00
笹井さんくさいね。論文を通さないといけない。レター論文は外さずにネイチャ再投稿と決まっている。この何が何だかわからない実験結果を何とか取りまとめなければならなかった。
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Thus, our findings indicate that epigenetic fate determination of mammalian cells can be markedly converted in a context-dependent manner by strong environmental cues.
78： 井伏鱒二 ：2019/02/28(木) 18:31:58
語彙選択ってそのとき読んでいた文章に影響されたりするよねえ。cuesって別に特段どうってことない語彙なんだろうけどね。Yang, J. et al.の文章にそういう表現が出てくると何か考えてたのかなあとふと思ってしまうけどな。
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This reprogramming is completely suppressed if cells are maintained in activin and Fgf, demonstrating the dominant influence of extrinsic cues.
脾臓細胞の内容に関して以下の記事があるわね。
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*ttps://www.researchgate.net/post/Size_of_mouse_splenocytes
>
5 years ago
Joseph michael Cantor
University of California, San Diego
5-10 um on average, with resting B and T cells comprising the lower end of the range and macrophages on the upper end. Adult mouse spleens typically contain 1x10e8 white blood cells: 50-60% B cells, 30% T cells, 5% macrophages, and <5% others.
Figure2-bは若山さん以外には誰も作れていないことになってる。STAP細胞は
Oct4を発現するんだけどFGF4誘導されたFI幹細胞もわずかにOct4遺伝子を発現しているんだね。
TS細胞はそれがないので全くTS様になったわけではないんだな。
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Despite their similarities, we noted that Fgf4-induced stem cells also possessed some critical differences compared with blastocyst-derived trophoblast stem cells. First, Fgf4-induced stem cells exhibited moderate GFP signals and expressed a moderate level of Oct4 (Fig. 2b; moderate and low levels of immunostaining signals were also seen for Oct4 and Nanog proteins, respectively; Extended Data Fig. 2c), unlike conventional trophoblast stem cells that have little Oct4 expression (Fig. 2e). Second, unlike trophoblast stem cells, blastocyst-injected Fgf4-induced stem cells also contributed to embryonic tissues (in all cases that involved chimaeric placentae; n = 32), although the extent of contribution was generally modest (Fig. 2g).
それらの類似性にもかかわらず、我々はFgf4誘導幹細胞は、胚盤胞由来栄養膜幹細胞と比較していくつかの重要な違いを持っていたことを指摘した。第一に、従来の栄養膜幹細胞がOct4蛋白発現が皆無であるのに対して(図2e)、Fgf4誘導幹細胞は適度なGFPシグナルを示し、そして適度なレベルOct4蛋白を発現した（図2b;中程程度および低いレベルで免疫染色シグナルが、それぞれ、Oct4とNanog蛋白質について見られた;拡張データ図2c）。第二に、栄養膜幹細胞とは異なり、胚盤胞に注入したFgf4誘導幹細胞は、寄与の程度は、一般的に控えめではあるものの（図2g）、胚組織にも寄与した（キメラ胎盤を含むすべてのケースにおいて;n = 32）、
ウィキのInner cell massに以下のような解説がある。
(*ttps://en.wikipedia.org/wiki/Inner_cell_mass)
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The physical and functional separation of the inner cell mass from the trophectoderm (TE) is a special feature of mammalian development and is the first cell lineage specification in these embryos. Following fertilization in the oviduct, the mammalian embryo undergoes a relatively slow round of cleavages to produce an eight cell morula. Each cell of the morula, called a blastomere, increases surface contact with its neighbors in a process called compaction. This results in a polarization of the cells within the morula, and further cleavage yields a blastocyst of roughly 32 cells.[1] In mice, about 12 internal cells comprise the new inner cell mass and 20 – 24 cells comprise the surrounding trophectoderm.[2][3] There is variation between species of mammals as to number of cells at compaction with bovine embryos showing differences related to compaction as early as 9-15 cells and in rabbits not until after 32 cells.[4] There is also interspecies variation in gene expression patterns in early embryos.[5]
In mice, about 12 internal cells comprise the new inner cell mass and
20 – 24 cells comprise the surrounding trophectoderm.[2][3] とあるところ、
32細胞期を既に初期胚盤胞としているね。
ここの説明ではコンパクションは8細胞期で起きると書かれている。
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Following fertilization in the oviduct, the mammalian embryo undergoes a relatively slow round of cleavages to produce an eight cell morula. Each cell of the morula, called a blastomere, increases surface contact with its neighbors in a process called compaction.
その件に関しては論文は以下のように書かれているのよ。
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Despite their similarities, we noted that Fgf4-induced stem cells also possessed some critical differences compared with blastocyst-derived trophoblast stem cells. First, Fgf4-induced stem cells exhibited moderate GFP signals and expressed a moderate level of Oct4 (Fig. 2b; moderate and low levels of immunostaining signals were also seen for Oct4 and Nanog proteins, respectively; Extended Data Fig. 2c), unlike conventional trophoblast stem cells that have little Oct4 expression (Fig. 2e). Second, unlike trophoblast stem cells, blastocyst-injected Fgf4-induced stem cells also contributed to embryonic tissues (in all cases that involved chimaeric placentae; n = 32), although the extent of contribution was generally modest (Fig. 2g).
論文上の理由ははっきり書かれてはいるのね。
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However, as Fgf4-induced stem cells lay between STAP stem cells and trophoblast stem cells in the dendrogram, the possibility of contamination of STAP stem cells in the Fgf4-induced stem-cell population cannot be ruled out.
先にe,fのリジェンドを見て置いたら?
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e, f, For an additional control, Fgf4-induced stem cells were plated in trophoblast stem-cell medium containing Fgf4 together with Oct4-GFP ES cells that constitutively expressed BFP (the number of plated cells was one-tenth of that of plated Fgf4-induced stem cells). Whereas BFP-expressing colonies (ES-cell-derived) still expressed Oct4-GFP in trophoblast stem-cell culture medium after 2 days (e), no Oct4-GFP+ colonies from BFP-expressing ES cells were observed in the JAK-inhibitor-treated culture (f).
<BFP-transfected Oct4-GFP ES cells>の説明があるね。
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Oct4-GFP ES cells that constitutively expressed BFP (the number of plated cells was one-tenth of that of plated Fgf4-induced stem cells)
