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标题: Skeletal Myogenic Differentiation of Mesenchymal Stem Cells Isolated from Human [打印本页]

作者: 江边孤钓    时间: 2009-3-5 10:37     标题: Skeletal Myogenic Differentiation of Mesenchymal Stem Cells Isolated from Human

Research Institute of Biotechnology, Histostem Co. Kangdong-gu, Seoul, Korea) Q% Z1 w8 T9 M  s9 H4 Y8 L" O

; V; f6 w9 U+ F: h# q; R' j; y  ~Key Words. Human umbilical cord blood ? Mesenchymal stem cells ? Immunophenotyping ? Myogenic differentiation% V1 ?' R8 @& T% m

! J- d2 b& B. f% aCorrespondence: Hoeon Kim, Ph.D., Research Institute of Biotechnology, Histostem Co. 518-4 Taijul Bldg, Doonchundong, Kangdong-gu, Seoul 134-060, Korea. Telephone: 82-2-470-9773; Fax: 82-2-470-6342; e-mail: hoeonkim@seoulcord.co.kr
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& Y8 f; ?3 c. iABSTRACT
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# t! N/ B2 e% z# {; h; tBone marrow (BM) has been regarded as a good source of both hematopoietic stem/progenitor cells and mesenchymal stem cells (MSCs) . These stem cells have the capacity for self-renewal and differentiating into cells of multiple lineages. MSCs derived from BM are capable of not only supporting hematopoiesis but also differentiating into mesodermal layer cells such as osteoblasts, chondrocytes, adipocytes, and myoblasts . However, the process to collect BM is invasive to donors and can cause complications such as infection, bleeding, and chronic pain, thereby limiting a wide application of BM-derived MSCs in tissue engineering and cell therapy.
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/ u  x7 r% D2 Z" L. GIn recent decades, human umbilical cord blood (UCB) has been explored as an alternative source to BM for cell transplantation and cell therapy because of its hematopoietic and nonhematopoietic (mesenchymal) components. In contrast to BM aspiration, human UCB is obtained by a simple, safe, and painless procedure when the baby is delivered. Since the late 1980s, UCB has become an indispensable source of hematopoietic stem/progenitor cells for transplantation of hematopoietic stem cells to treat some hematological disorders . However, human UCB has been controversial for the presence of MSCs; some researchers successfully isolated MSCs from UCB, whereas others have not . Nevertheless, several groups reported that the UCB-derived MSCs could proliferate ex vivo and differentiate, at least, into osteoblasts and adipocytes . No evidence has shown yet that UCB-derived MSCs differentiate into skeletal myoblasts, but they are believed to have such a potential.
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% L& t* {- b" D1 E1 r% F5 rMyogenic differentiation is regulated by a family of myogenic regulatory factors (MRFs), including Myf5, MyoD, myogenin, and MRF4; MyoD and Myf5 are required for the determination of skeletal myogenic lineages, whereas myogenin and MRF4 are thought to regulate cell fusion and terminal differentiation . In postnatal life, the satellite cells located between muscle fiber sarcolemma and basal lamina are quiescent myoblasts, but they are fully determined to myogenic phenotype so that, once activated, they are capable of terminal differentiation . The quiescent satellite cells do not express transcription factors of a MRF family, whereas the activated ones exhibit a battery of molecular markers of Myf5, MyoD, and, to a lesser extent, myogenin. These satellite cells were once regarded as an ideal source for muscle regeneration and repair, but it turned out that they were few in injured muscle and that they were exhausted immediately during healing processes. A search for an alternative source with equivalent myogenic potential yielded MSCs not long ago when the BM-derived MSCs were shown to expand in vitro and differentiated successfully into myoblasts ./ d( X% {( ?1 ]+ e- u
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In this paper, we report that fibroblast-like cells from human UCB, exhibiting mesenchymal phenotypes, are also able to differentiate into cells that express several skeletal muscle–specific genes. Our findings implicate that UCB is a potential source of MSCs for therapy of degenerative muscular diseases or muscle damage/loss from trauma.! ~) r8 l& k' U/ V% t
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MATERIALS AND METHODS6 M+ ~/ t& u% ^/ h, A* H+ g

0 i6 N  h, a3 W% tCharacteristics of UCB-Derived Adherent Cells
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: I. o* t. A0 F  A  o5 YThe mononuclear cells were obtained from UCB by Ficoll-Paque density gradient centrifugation and plated in the culture flasks. After 5 days of culture, nonadherent cells were removed by medium change. The adherent cells were small and rounded in shape. These cells grew larger and seemed to be comprised of heterogeneous cells, as judged by their appearance. The elongated cells began to appear among rounded cells between 8 and 15 days of culture, and they continued to grow to become fibroblast-like cells. By two or three passages of culture, the adherent cells became a population comprised mainly of bipolar fibroblast-like cells and could grow to confluency.1 \. \) c9 `$ e* u

' {1 y- Z) e- I  L: [We examined the proliferation characteristics of the fibroblast-like cells at the fourth passage. The population-doubling time of cells is approximately 60 hours, as determined by viable counting. FACS analysis showed that 86% of cells were in the phase of G0/G1.
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$ i+ r0 r: L  T* n# O! e5 XImmunophenotyping of UCB-Derived Adherent Cells* P1 |1 G! R) P: W) p
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To characterize the adherent cell population derived from UCB, expression of a variety of CD markers and intracellular antigens like ASMA was examined by flow cytometry. Those adherent cells expressed CD13, CD29 (? 1 integrin), CD44, CD49e (5 integrin), CD54 (ICAM-1), CD90 (Thy-1), ASMA, CD105/SH2/endoglin, and CD73/SH3 (Fig. 1). Among these, SH2 and SH3 are well known as MSC-specific antigens. They expressed neither hematopoietic lineage markers such as CD34 nor monocyte-macrophage antigens such as CD14 and CD45 (Fig. 1). The lack of expression of CD14, CD34, and CD45 suggests that cell cultures were depleted of hematopoietic cells during subcultivation.
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: A- z  ]* L* y" ?/ H; ~. l. TFigure 1. Immunophenotyping of umbilical cord blood–derived mesenchymal stem cells. Mesenchymal stem cells were detached, labeled with FITC- or phycoerythrin-conjugated monoclonal antibodies, and detected by flow cytometry. Relative number cells (counts) versus fluorescence intensity are presented. Abbreviations: ASMA, -smooth muscle actin; FITC, fluorescein isothiocyanate.+ ~' j) C/ l' I2 N

- {+ ]7 q% ]% vThe adherent cells were also negative for expression of CD49d (4 integrin), CD106 (VCAM-1), and CD31 (an endothelial-related antigen) (Fig. 1). Similar to BM-derived MSCs, the cell population was positive for HLA class I but not for HLA DR (Fig. 1). All data above indicate that the adherent cells derived from UCB exhibit the phenotype of MSCs.0 d9 x' u- P3 v# {9 \* U& X7 q7 h
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FACS and Reverse Transcription–PCR Analyses of Myogenic Differentiation
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, W: D' C2 ~! h! |A potential of UCB-derived MSCs differentiating into osteoblasts, chondrocytes, and adipocytes was demonstrated elsewhere . To investigate whether UCB-derived MSCs show a potential to differentiate into skeletal muscle cells, MSCs were cultured for up to 6 weeks in myogenic medium containing dexamethasone and hydrocortisone. At different time intervals, treated cells were observed by phase-contrast microscopy and then analyzed by flow cytometry with monoclonal antibodies against two muscle-specific transcription factors, MyoD and myogenin, as well as a skeletal protein, fast-twitch myosin. At week 1, MyoD and myogenin were expressed in approximately 8.7% and 90% of the treated cells, respectively, whereas non-treated cells remained unstained against anti-MyoD and anti-myogennin antibodies (Fig. 2A). However, the expression of MyoD and myogenin quickly vanished from week 2. This result is consistent with the fact that the two factors are involved in early myogenesis., R" [( U0 X6 x( {2 l" m' ?5 q9 x

, i1 p1 s4 N0 E' L# I3 M& R! BFigure 2. Myogenic differentiation of MSCs isolated from human umbilical cord blood. (A): After 1 and 2 weeks of induction in myogenic medium, cultures were analyzed by FACS for MyoD1 and myogenin. (B): Cells were incubated with myogenic medium for up to 6 weeks and were then analyzed by FACS for fast-twitch myosin. (C): MyoD1, myogenin, and myosin heavy chain mRNA levels were measured by reverse transcription–polymerase chain reaction during MSC differentiation in myogenic medium. For corresponding controls, cells were cultured in control medium (culture medium with no addition of dexamethasone and hydrocortisone). Abbreviations: FACS, fluorescence-activated cell sorting; MSC, mesenchymal stem cell.8 b6 ]' A/ B6 S

: ]/ h. T* j; w' w+ w! vOn the other hand, fast-twitch myosin began to express only after 3 weeks of induction, and approximately 55.7% of treated MSCs at week 6 were visibly stained with monoclonal anti-skeletal myosin antibodies (Fig. 2B). This finding is also not surprising when considering that myosin is an element of skeletal muscle fibers that appears in late myogenesis.& `, s- N/ k) q$ V# |. R% k* n

# a- O) p& n7 \Skeletal myoblast differentiation of UCB-derived MSCs was also analyzed by semiquantitative reverse transcription (RT)-PCR of MyoD, myogenin, and MyHC. None of these factors were significantly expressed in the cells treated with nonmyogenic medium. In the case of the cells treated with myogenic medium, however, the mRNA levels of both MyoD and myogenin were significantly increased after 3 days (Fig. 2C). At week 1, the mRNA level of myogenin was highly increased to reach a presumed peak, whereas that of MyoD subsided quickly. The mRNA levels of both factors were almost abolished after 2 weeks (Fig. 2C). The mRNA of MyHC, on the other hand, appeared after 3 weeks of induction, and its expression steadily increased until the sixth week (Fig. 2C).% y* d; q; u6 U5 Y2 H2 w, A
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Immunocytochemical Analysis of Myogenic Differentiation
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2 P0 H: T. N; h3 K8 QTo further confirm myogenic differentiation of UCB-derived MSCs, cells were examined immunocytochemically with monoclonal anti-MyoD, anti-myogenin, and anti-skeletal myosin antibodies. Figure 3A shows nuclear staining of MyoD and myogenin in treated cells. Consistent with our previous RT-PCR and FACS results, expression of myogenin was much higher than that of MyoD at 1 week of induction (Fig. 3A). Western blot analysis indicated that fast-twitch myosin, which appeared as a 200,000-dalton protein band, was highly expressed in the cells incubated for 6 weeks (Fig. 3B). Taken together with the data above, it is very likely that human UCB-derived MSCs are able to differentiate into skeletal myoblasts.
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, }' y- V8 Y5 o, l6 z7 H; v& lFigure 3. Immunocytochemistry and Western blotting of umbilical cord blood–derived mesenchymal stem cells cultured in myogenic medium. (A): Immunocytochemical staining of the cells cultured in myogenic medium for 1 week. The cells were stained with MyoD or myogenin antibodies followed by a horseradish peroxidase (HRP)–conjugated secondary antibody and were colorized with the substrates. The control was stained only with the secondary antibody. (B): Western blot of the protein extract from the cells cultured in myogenic medium for 6 weeks. The blot was stained with a fast-twitch antibody followed by an HRP–conjugated secondary antibody. The level of -actin protein was used as a loading control.
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This research was supported in part by a grant (SC13032) from Stem Cell Research Center of the 21st Century Frontier Research Program funded by the Ministry of Science and Technology and a grant (01-PJ10-PG8-01EC01-0015) of Korea Health 21 R&D Project funded by the Ministry of Health and Welfare, Republic of Korea.
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- d0 {! a5 K8 x  i7 G) O+ B/ O/ DREFERENCES
. n8 E% {3 G4 A; @! O! P
7 t  M# y) `  }! g5 t4 g/ b' [Golfier F, Barcena A, Harrison MR et al. Fetal bone marrow as a source of stem cells for in utero or postnatal transplantation. Br J Haematol 2000;109:173–181.) M# k6 B8 h! ?
3 i4 q0 i2 Z+ b+ d! v
Reyes M, Lund T, Lenvik T et al. Purification and ex vivo expansion of postnatal human marrow mesodermal progenitor cells. Blood 2001;98:2615–2625.9 e! z5 T0 S5 e/ z6 |& ?4 ?% h" g+ `

6 ]1 I4 F# w( `5 dAlbella B, Segovia JC, Guenechea G et al. Ex vivo expansion of hematopoietic stem cells. Methods Mol Biol 2003;215:363–373.: L4 W* E  C& J* ]9 d! u

  Q: h. [9 U3 g9 U, N2 _Jones EA, Kinsey SE, English A et al. Isolation and characterization of bone marrow multipotential mesenchymal progenitor cells. Arthritis Rheum 2002;46:3349–3360.' u/ L/ l! \3 A

6 }6 |- a% j, ^( I& \! {, Q8 S+ cSekiya I, Larson BL, Smith JR et al. Expansion of human adult stem cells from bone marrow stroma: conditions that maximize the yields of early progenitors and evaluate their quality. STEM CELLS 2002;20:530–541.: I/ P2 d. m' Z4 C6 j+ q
) ^# s! y3 B. m. S5 f3 E% D6 T7 ?
Pittenger MF, Mackay AM, Beck SC et al. Multilineage potential of adult human mesenchymal stem cells. Science 1999;284:143–147.
2 ~- r& {4 K( ?0 ~) m) |1 G4 J
" v7 \2 i/ ~# s2 ^5 y; F8 r. F' \Imabayashi H, Mori T, Gojo S et al. Redifferentiation of dedifferentiated chondrocytes and chondrogenesis of human bone marrow stromal cells via chondrosphere formation with expression profiling by large-scale cDNA analysis. Exp Cell Res 2003;288:35–50.
- P/ a2 u! c/ F5 d& u6 q5 M: D* w0 e, P4 w) I. S
Wakitani S, Saito T, Caplan AI. Myogenic cells derived from rat bone marrow mesenchymal stem cells exposed to 5-azacytidine. Muscle Nerve 1995;18:1417–1426.
1 k* A4 H. y# j- U, J% v$ Y
6 ^; n# \& V3 Z' Y* `8 ]1 O) h. aCohena Y, Nagler A. Hematopoietic stem-cell transplantation using umbilical cord blood. Leuk Lymphoma 2003;44:1287–1299.
5 E" q' V8 I4 |) I! q
2 c0 b1 f" {% w/ U9 O4 `' c1 v. I$ gLong GD, Laughlin M, Madan B et al. Unrelated umbilical cord blood transplantation in adult patients. Biol Blood Marrow Transplant 2003;9:772–780.% j" s* D; q$ [, o4 T) X  F( }& O4 e
% `0 s6 @2 u! }, B: k' ^
Ooi J, Iseki T, Takahashi S et al. Unrelated cord blood transplantation for adult patients with de novo acute myeloid leukemia. Blood 2004;103:489–191.
& a& r  X) l8 @$ S2 V
( w3 F! ]. P5 U* TFrassoni F, Podesta M, Maccario R et al. Cord blood transplantation provides better reconstitution of hematopoietic reservoir compared with bone marrow transplantation. Blood 2003;102:1138–1141.
* |# F0 C- [& z8 C, `3 j' p: k) X" g0 u. w; \' U- I$ h; Q
Bhattacharya A, Slatter M, Curtis A et al. Successful umbilical cord blood stem cell transplantation for chronic granulomatous disease. Bone Marrow Transplant 2003;31:403–405.9 H, F$ I. [6 }/ s

; A+ l: u/ n2 P) w, z+ ~: f2 tLaughlin MJ, Barker J, Bambach B et al. Hematopoietic engraftment and survival in adult recipients of umbilical-cord blood from unrelated donors. N Engl J Med 2001;344:1815–1822.) d* U0 l5 a9 V6 l/ p1 l
1 ]6 K& K: O4 _6 y8 M" o
Wexler SA, Donaldson C, Denning-Kendall P et al. Adult bone marrow is a rich source of human mesenchymal "stem" cells but umbilical cord and mobilized adult blood are not. Br J Haematol 2003;121:368–374.
6 a1 Z) t# B" x9 J( T7 V" ^5 [
2 C( X9 D3 D2 k& cMareschi K, Biasin E, Piacibello W et al. Isolation of human mesenchymal stem cells: bone marrow versus umbilical cord blood. Haematologica 2001;861099–1100.
' W; Z( I$ r8 _: b7 V8 E$ U. G  x& x5 A, v
Erices A, Conget P, Minguell JJ. Mesenchymal progenitor cells in human umbilical cord blood. Br J Haematol 2000;109:235–242.
# Y! D/ E- [& ]5 K! e) {5 g( J! X3 I: L2 A( `
Goodwin HS, Bicknese AR, Chien SN et al. Multilineage differentiation activity by cells isolated from umbilical cord blood: expression of bone, fat, and neural markers. Biol Blood Marrow Transplant 2001;7:581–588.% ]& S7 O6 I- B. B0 N+ v8 I' x

! I& F# \/ _3 P, ]; q7 n1 l7 k$ lRomanov YA, Svintsitskaya VA, Smirnov VN. Searching for alternative sources of postnatal human mesenchymal stem cells: candidate MSC-like cells from umbilical cord. STEM CELLS 2003;21:105–110.; P+ ~9 `' B4 P- P* @- X9 Y2 z7 H  N

0 d3 H7 G. ?( O- |Aurade F, Pinset C, Chafey P et al. Myf5, MyoD, myogenin and MRF4 myogenic derivatives of the embryonic mesenchymal cell line C3H10T1/2 exhibit the same adult muscle phenotype. Differentiation 1994;55:185–192.( z9 s+ Y7 H7 f6 T

7 F" |9 R1 _# ^4 d' H( E. F$ kRohwedel J, Maltsev V, Bober E et al. Muscle cell differentiation of embryonic stem cells reflects myogenesis in vivo: developmentally regulated expression of myogenic determination genes and functional expression of ionic currents. Dev Biol 1994;164:87–101." S$ T# o! L) X! S& f" N8 Q

; v" v- U( [  R6 a% U) R6 C7 fShimokawa T, Kato M, Ezaki O et al. Transcriptional regulation of muscle-specific genes during myoblast differentiation. Biochem Biophys Res Commun 1998;246:287–292.+ C2 O- o$ z3 t* W  C

3 R* z4 p$ |% G2 W0 VValdez MR, Richardson JA, Klein WH et al. Failure of Myf5 to support myogenic differentiation without myogenin, MyoD, and MRF4. Dev Biol 2000;219:287–298.
5 R+ Z' d/ B; }/ k- b
4 R. p0 m6 S% ~9 ~  VRantanen J, Hurme T, Lukka R et al. Satellite cell proliferation and the expression of myogenin and desmin in regenerating skeletal muscle: evidence for two different populations of satellite cells. Lab Invest 1995;72:341–347.& A! V/ H! b7 f
4 c" k, \' \0 R- w& p% d4 i8 G# N
Schultz E. Satellite cell proliferative compartments in growing skeletal muscles. Dev Biol 1996;175:84–94.
* l0 e* ]% U$ a
) z" X1 I& c. T& T# gZammit P, Beauchamp J. The skeletal muscle satellite cell: stem cell or son of stem cell? Differentiation 2001;68:193–204./ [/ ]  L) D4 Q# x; ~" L: x
7 a9 U0 {. U0 \" _7 Q
De Angelis L, Berghella L, Coletta M et al. Skeletal myogenic progenitors originating from embryonic dorsal aorta coexpress endothelial and myogenic markers and contribute to postnatal muscle growth and regeneration. J Cell Biol 1999;147:869–878.4 a2 S& e/ V: D5 u

, L9 {7 v7 ^1 J* _. L6 VZuk PA, Zhu M, Mizuno H et al. Multilineage cells from human adipose tissue: implications for cell-based therdapies. Tissue Eng 2001;7:211–228.
: H2 Q4 S  {' w5 o  Z* d, N& Q' _' p( a% d, P
Mizuno H, Zuk PA, Zhu M et al. Myogenic differentiation by human processed lipoaspirate cells. Plast Reconstr Surg 2002;109:199–209.
3 }! J% h( y9 I7 q5 ^; G( Y0 p# F; s% a! t
Zuk PA, Zhu M, Ashjian P et al. Human adipose tissue is a source of multipotent stem cells. Mol Biol Cell 2002;13:4279–4295.4 V# J) U# H' J3 [# F# u

( \0 N) b! N3 V+ u' IMichelagnoli MP, Burchill SA, Cullinane C et al. Myogenin: a more specific target for RT-PCR detection of rhabdomyosarcoma than MyoD1. Med Pediatr Oncol 2003;40:1–8.7 D1 ^" x" e6 s& T" g! c4 P* Q$ q

" s) w! f8 Q8 LUeda T, Araki N, Mano M et al. Frequent expression of smooth muscle markers in malignant fibrous histiocytoma of bone. J Clin Pathol 2002;55:853–858.
9 H/ B0 }/ G0 e" k5 D  Z5 X/ w- x% z) o& `4 h: R+ d
Edmondson DG, Olson EN. Helix-loop-helix proteins as regulators of muscle-specific transcription. J Biol Chem 1993;268:755–758.(Eun Ji Gang, Ju Ah Jeong,)
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一定要回贴,因为我是文明人哦  
作者: haha3245    时间: 2017-7-28 00:57

小生对楼主之仰慕如滔滔江水连绵不绝,海枯石烂,天崩地裂,永不变心.  
作者: haha3245    时间: 2017-8-16 05:34

支持~~  
作者: 快乐小郎    时间: 2017-8-17 06:00

我帮你 喝喝  
作者: netlover    时间: 2017-8-22 09:34

我在顶贴~!~  
作者: Diary    时间: 2017-9-1 08:43

支持~~顶顶~~~  
作者: 水木清华    时间: 2017-9-10 07:58

肿瘤干细胞
作者: s06806    时间: 2017-9-13 23:28

我又回复了  
作者: Whole    时间: 2017-9-19 02:23

顶下再看  
作者: dypnr    时间: 2017-10-16 02:30

我十目一行也还是看不懂啊  
作者: 加菲猫    时间: 2017-10-23 10:36

先看看怎么样!  
作者: dataeook    时间: 2017-10-28 17:43

说的不错  
作者: 某某人    时间: 2017-11-15 06:17

这样的贴子,不顶说不过去啊  
作者: changfeng    时间: 2017-11-21 07:10

加油啊!偶一定会追随你左右,偶坚定此贴必然会起到抛砖引玉的作用~  
作者: 甘泉    时间: 2017-11-24 04:34

不错,看看。  
作者: ikiss    时间: 2017-11-28 10:35

小心大家盯上你哦  
作者: 生物小菜鸟    时间: 2017-12-2 19:41

是楼主原创吗  
作者: 365wy    时间: 2017-12-9 21:35

在线等在线等  
作者: dd赤焰    时间: 2017-12-19 02:53

干细胞产业是朝阳产业
作者: 追风    时间: 2017-12-24 07:57

怎么就没人拜我为偶像那?? ~  
作者: 生科院    时间: 2018-1-2 15:01

人之所以能,是相信能。  
作者: bluesuns    时间: 2018-1-8 06:05

祝干细胞之家 越办越好~~~~~~~~~`  
作者: s06806    时间: 2018-1-9 23:16

彪悍的人生不需要解释。  
作者: 张佳    时间: 2018-1-17 01:40

这个贴不错!!!!!  
作者: 兔兔    时间: 2018-1-18 19:15

脂肪干细胞
作者: 初夏洒脱    时间: 2018-1-23 15:28

楼主福如东海,万寿无疆!  
作者: xiaomage    时间: 2018-1-24 11:18

支持你一下下。。  
作者: 3344555    时间: 2018-1-24 20:50

只有一条路不能选择——那就是放弃的路;只有一条路不能拒绝——那就是成长的路。  
作者: xiaomage    时间: 2018-3-7 21:49

干细胞研究还要面向临床
作者: abc987    时间: 2018-3-11 05:31

我该不会是最后一个顶的吧  
作者: 锦锦乐道    时间: 2018-3-22 18:15

我十目一行也还是看不懂啊  
作者: apple0    时间: 2018-3-25 18:27

干细胞研究还要面向临床
作者: biodj    时间: 2018-4-6 08:27

dddddddddddddd  
作者: IPS干细胞    时间: 2018-4-8 03:03

干细胞美容
作者: 碧湖冷月    时间: 2018-4-15 17:52

不错啊! 一个字牛啊!  
作者: Greatjob    时间: 2018-4-15 21:53

不错不错.,..我喜欢  
作者: 依旧随遇而安    时间: 2018-4-17 03:00

支持你加分  
作者: dd赤焰    时间: 2018-4-28 19:18

终于看完了~~~  
作者: 命运的宠儿    时间: 2018-5-21 13:43

谢谢干细胞之家提供资料
作者: 20130827    时间: 2018-5-27 23:59

活着,以死的姿态……  
作者: 小敏    时间: 2018-6-3 20:01

留个脚印```````  
作者: xm19    时间: 2018-6-6 04:35

一楼的位置好啊..  
作者: Greatjob    时间: 2018-6-8 07:30

我十目一行也还是看不懂啊  
作者: 生科院    时间: 2018-6-13 17:48

这个站不错!!  
作者: 兔兔    时间: 2018-6-18 16:57

每天早上起床都要看一遍“福布斯”富翁排行榜,如果上面没有我的名字,我就去上班……  
作者: 舒思    时间: 2018-7-2 03:31

今天没事来逛逛  




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