Journal of Stem Cells & Regenerative Medicine - Volume 5 Issue1; 2009

Expanding horizons

Webmaster-JSRM — 1 Apr 2009 04:56:33 GMT

Journal:
2009 Vol. 5 (1): p1-2

Published on:
Apr 2009

Author(s):
Editorial

Dear Friends,

The debate of whether Stem Cell Therapy is a hype or hope has been raging for quite some time and has been rekindled in the current year.

Stem Cell Scientists have been particularly enthused by the bold standard taken by Barack Obama in passing an Executive Order that lifted the ban on federal funding of Research on Embryonic Stem Cell (ESC) lines created after August 9, 2001. With the lifting of the ban more money is expected to be poured into ESC and Stem Cell Research in general and this augurs well for this emerging science. This is hope.

Amariglio et al have reported the occurrence of a multifocal brain tumor in a boy with ataxia telengectasia four years after he was treated with intracerebella and intrathecal injection of human fetal neural stem cells. Molecular and Cytogenetic studies showed that the tumor was of non host origin raising the possibility of it being derived from transplanted neural stem cell. This is the first report of a donor-derived brain tumor in neural stem cell therapy and opens a Pandora's Box of questions about the safety of such therapies. This signifies the hype surrounding the therapy.

However controversies are a part of any emerging science. Our goals should be to march forward conducting our research under strict ethical principles and rigorous oversight, ironing out even minor flaws, always being on the lookout for adverse events and identifying ways and means of preventing their occurrence in future.

JSRM has been in receipt of six articles, which speaks well for the interest people have for stem cell science in general and our journal in particular.

The articles we have received for this edition of JSRM cover all aspects necessary for a science. Rosen et al have described the percentage variation of adipose stromal cells isolated from two different inbred mouse strains and Bhonde et al have reported the existence of multipotent stem cells in human fallopian tube. If cells can be identified, isolated they need suitable media for expansion and delivery. Dr. H.N. Madhavan et al article describes the use of such a medium (Mebiol Gel) for transplanting corneal limbal stem cells. Even if cells are ready for delivery, we should first have suitable animal models to test them and the article Garikipati Venkata Naga Srikanth et al is a good article describing are such animal model, that can be used to testing efficacy of stem cell.

Aoyama et al article on using cell therapy for avascular osteonecrosis of femoral head reiterates the fact that stem cell therapy has a potential to cure a wide range of diseases and encourages all of us to continue in our guest to take stem cell therapy to treat hither to untreatable diseases.

The article by Senthil Kumar Pazhanisamy et al highlights the fact that our current understanding of genome instabilities is limited. It is my personal opinion that with a better understanding of genome organization (which may take several years) we can possibly predict the occurrence of tumorogenesis and reject such stem cells obtained at source from possible use in therapy. So that we would have no more cases of tumors post stem cell therapy

Happy reading!

Yours sincerely,

The Editorial team.

Corneal surface reconstruction - a short review

1 Apr 2009 04:56:33 GMT

Journal:
2009 Vol. 5 (1): p7-10

Published on:
Apr, 2009

Author(s):
Madhavan H N

Cornea is the clear, dome-shaped surface that covers the front of the eye and when damage due to burns or injury and several other diseases, stem cells residing in its rim called "limbus" are stimulated to multiply to support growth of new epithelial cells over its surface. If this ready source of stem cells is damaged or destroyed the natural repair is not possible and such a condition is known as corneal limbal stem cell deficiency (CLSCD) disease. Stem cell transplant helps such persons to regenerate the corneal surface. Human corneal limbal stem cell transplantation is at present an established procedure with reasonable good clinical outcome particularly when autologous limbal epithelial tissue from a fellow unaffected eye is used. 1, 2 A major concern related to the autograft is the possibility of CLSCD at the donor site, 3 techniques that allowed the expansion of a small limbal biopsy in the laboratory using cell cultures that could be then transplanted to the affected eye have been developed ,4, 5

Human amniotic membrane (HAM) is used as a scaffold for both culturing the human limbal epithelial cells and for ocular surface reconstruction with the cultured limbal epithelial cells. 4-7 However, researchers have used alternative scaffolds like collagen 8, fibrin gel 9 and cross-linked gel of fibronectin and fibrin. 10 All these are biological materials and also need for animal 3T3 feeder layer for stem cell cultures.

The properties of HAM are unique including antiadhesive effects, bacteriostatic effects, wound protection, pain reduction, and improvement of epithelialization and characteristically lacking imunogenicity. The use of amniotic membrane transplantation (AMT) to treat ocular surface abnormalities was first reported by Graziella Pellegrini, chief of stem cell laboratory at Giovanni Paolo Hospital in Venice, Italy, who was the first to demonstrate the limbal stem cell transplant in 1997. Amniotic membrane has been successfully used in patients with persistent epithelial defects, pterygium, symblepharon, and for ocular surface reconstruction. The role of AMT in ocular disorders has been recently re-evaluated by Schwab and coworkers.11 They carefully examined the protocols used in the manufacture of the bio-engineered construct to assess the risks and reviewed 20 published reports of human trials conducted between 1996 and 2005 in a report suggesting that the currently used transplant procedures carry potential health risks not only to individuals but also to "the wider community" because they "rely on the use of materials from animal and human donors". Their review revealed that most protocols used animal-derived products including fetal calf serum (FCS) with a potential for transmissible spongiform encephalopathy (TSE) infection (of the brain) or allergic reactions and further state that the use of commercially available fibrin tissue "adds to the risk of microbial or prion contamination". Since no investigations have been done, the use of AMT can potentially induce "disease transmission through contamination with bacteria, viruses, or other infectious agents", they also stated that with 3T3 cells being commonly used (that come from mice) possibilities of "xenozoonosis", or animal-to-human disease transmission are a concern.

Several studies have been undertaken using oral mucosal epithelial cells cultivated on amniotic membrane for useful tissue engineering of damaged corneal surface. Higa and Shimazaki have carried out a study of transplantation in cultivated oral mucosal epithelial which has been useful in achieving a stable ocular surface. However, in addition to using epithelial sheets with AM, they developed a technique for generating carrier-free sheets using fibrin sealants. These sheets seem to contain more differentiated epithelium than those obtained with AM while retaining similar levels of colony-forming progenitor cells. In terms of isolation and cultivation of corneal epithelial stem/progenitor cells, we found that single murine limbal cells exhibited clonal growth and generated stratified epithelial sheets. 12 Dogru et al determined the barrier function and cytologic features of ocular surface epithelium after autologous cultivated oral mucosal epithelial transplantation in a prospective observational study. Cultivated oral mucosal epithelial cells were observed to survive for more than 1 year after transplantation, with gradual replacement by conjunctival epithelium in some cases. Decreased barrier function of the transplanted epithelium may have prognostic implications, suggesting the presence of oral mucosal epithelium long after surgery. 13 Oral epithelial sheets cultivated in autologous serum (AS) and fetal bovine serum-supplemented media were similar in morphology, and both formed basement membrane assembly proteins important for maintaining graft integrity. Complete corneal epithelialization was achieved within 2 to 5 days postoperatively. The successful use of an AS-derived oral epithelial equivalent to treat severe ocular surface disease represents an important advance in the pursuit of completely autologous xenobiotic-free bioengineered ocular equivalents for clinical transplantation. 14

Since most of these studies used heterologous carrier for growth of corneal limbal cells with attendant likely complications, we developed a novel method of cultivation of human limbal cells in a synthetic material as a culture substrate and the material we chose was Mebiol Gel (Provided by Mebiol Inc., Japan through Nichi-In Bio Sciences PVT Ltd, Chennai, India).

Mebiol Gel is a copolymer composed of thermo responsive polymer block [poly (Nisopropylacrylamide-co-n-butyl methacrylate) (poly NIPAAm-co-BMA)] and the hydrophilic polymer block [polyethylene glycol (PEG)]. This polymer block is hydrophilic at temperatures below 20oC and hydrophobic at temperatures above 20°C forming cross-linking points and homogenous three dimensional (3-D) network of Mebiol Gel in water. Cells or tissues can be embedded in a liquid Mebiol gel solution at lower than 20°C and cultured three dimensionally in a hydrogel state at 37°C. The sol-gel transition temperature can be controlled by altering chemical composition of thermo-reversible gelation polymer (TGP). Mebiol Gel prevents the growth of the fibroblasts and it is not toxic to cells. In our earlier study, continuous culture cell lines 18 and we demonstrated that Mebiol Gel supported the growth of corneal limbal epithelial cells and these cells expressed both limbal and corneal phenotype, suggesting that limbal epithelial cells cultivated in Mebiol Gel would be a promising material for corneal surface tissue engineering.

With this in view, we developed a novel method of cultivation of human limbal cells in a synthetic scaffold made of a thermo reversible polymer, that allows the limbal epithelial cells to survive, proliferate and differentiate into corneal epithelial cells and demonstrated the effectiveness of this polymer for corneal tissue engineering using an experimentally induced limbal deficiency in a rabbit model. In this report, the detailed procedure of the animal model and the results are discussed. We evaluated the efficacy of autologous expanded corneal epithelial cell transplants derived from harvested limbal biopsy cultured on a thermo-reversible polymer (Mebiol Gel) for the management of unilateral limbal stem cell disease (LSCD).Corneal limbal biopsies from 12 rabbits were cultured on Mebiol Gel at 37°C. Cells were harvested from the dishes after 3 weeks by reducing temperature to 4°C. Autologous transplantation was undertaken to reconstruct the experimentally induced limbal stem cell deficiency in the rabbit eyes. The corneas of both eyes of all rabbits were harvested later for histological and RT-PCR studies. Reparative surgery was a total success in 7 (58.3%; score, 8-10), partial success in 2 (16.7%; score, 6-7) and failure in 3 (25%; score, <5). Histological and RT-PCR study documented successful growth of corneal epithelium onto the recipient surface. Our results suggest that transplantation of autologous limbal epithelial cells grown in thermo-reversible gel polymer may restore a nearly normal ocular epithelial surface in eyes with unilateral LSCD. 15

We believe that use biodegradable and thermo-reversible Mebiol Gel as the cultivation carrier will be most useful with no attending complication for corneal limbal stem cell transplantation in patients who need such a procedure.

References

1. Kenyon K, Tseng SC. Limbal autograft transplantation for ocular surface disorders. Ophthalmology 1989; 96: 709.

2. Tsubota K, Satake Y, Kaido M, Shinozaki N, Shimmura S, Bissen-Miyajima H, Shimazaki J. Treatment of severe ocular-surface disorders with corneal epithelial stem-cell transplantation. N Engl J Med. 1999; 340:1697-703.

3. Chen JJ, Tseng SC. Corneal epithelial wound healing in partial limbal deficiency. Invest Ophthalmol Vis Sci 1990; 31:1301-14.

4. Schwab IR, Reyes M, Isseroff RR. Successful transplantation of bioengineered tissue replacements in patients with ocular surface disease. Cornea 2000; 19:421-6.

5. Tsai RJ, Li LM, Chen JK. Reconstruction of damaged corneas by transplantation of autologous limbal epithelial cells. N Engl J Med 2000; 343:86-93.

6. Koizumi N, Inatomi T, Quantock AJ, Fullwood NJ, Dota A, Kinoshita S. Amniotic membrane as a substrate for cultivating limbal corneal epithelial cells for autologous transplantation in rabbits. Cornea 2000; 19, 1965-71.

7. Shimazaki J, Aiba M, Goto E, Kato N, Shimmura S, Tsubota K. Transplantation of human limbal epithelium cultivated on amniotic membrane for the treatment of severe ocular surface disorders. Ophthalmology. 2002; 109:1285-1290.

8. Schwab I. Cultured corneal epithelia for ocular surface disease. Trans Am Ophthalmol Soc 1999; 97: 891-986

9. Rama P, Bonini S, Lambiase A, Golisano O, Paterna P, De Luca M, Pellegrini G. Autologous fibrin-cultured limbal stem cells permanently restore the corneal surface of patients with total limbal stem cell deficiency. Transplantation 2001; 72: 1478-85.

10. Han B, Schwab IR, Madsen TK, Isseroff RR. A fibrin-based bioengineered ocular surface with human corneal epithelial stem cells. Cornea. 2002; 21:505:510.

11. Schwab IR, Johnson NT, Harkin DG. Inherent risks associated with manufacture of bioengineered ocular surface tissue Arch Ophthalmol. 2006 Dec;124(12):1734-40).

12. Higa K, Shimazaki J. Recent advances in cultivated epithelial transplantation.. Cornea. 2008 Sep;27 Suppl 1:S41-7

13. Satake Y, Dogru M, Yamane GY, Kinoshita S, Tsubota K, Shimazaki J Barrier function and cytologic features of the ocular surface epithelium after autologous cultivated oral mucosal epithelial transplantation.Satake Arch Ophthalmol. 2008 Jan;126(1):23-8.

14. Ang LP, Nakamura T, Inatomi T, Sotozono C, Koizumi N, Yokoi N, Kinoshita S.
Autologous serum-derived cultivated oral epithelial transplants for severe ocular surface disease. Arch Ophthalmol. 2006 Nov;124(11):1543-51

15. Sitalakshmi. G, Sudha B, Madhavan HN, Vinay S, Krishnakumar S, Mori Yuchi, Hiroshi Yoshioka, Samuel Abraham. "Ex vivo cultivation of corneal Limbal epithelial cells in a Thermo-reversible polymer (Mebiol Gel) and their transplantation in Rabbits an animal model." Tissue Engineering. Feb 2009, Vol. 15, No. 2: 407-415.

Cell therapy for avascular osteonecrosis of femoral head

1 Apr 2009 04:56:33 GMT

Journal:
2009 Vol. 5 (1): p3-6

Published on:
Apr 2009

Author(s):
Tomoki Aoyama, Junya Toguchida

Abstract:
Avascular osteonecrosis of femoral head causes severe musculoskeletal disability. There is not standard treatment to cure avascular osteonecrosis. Recently, cell therapy using bone marrow stromal cells has begun for this disease.

Keywords:
avaslucar osteonecrosis, cell transplantation, mesenchymal stem cells

Genome organization, instabilities, stem cells, and cancer

1 Apr 2009 04:56:33 GMT

Journal:
2009 Vol. 5 (1): p11-22

Published on:
Apr, 2009

Author(s):
Senthil Kumar Pazhanisamy, Vinu Jyothi

Abstract
It is now widely recognized that advances in exploring genome organization provide remarkable insights on the induction and progression of chromosome abnormalities. Much of what we know about how mutations evolve and consequently transform into genome instabilities has been characterized in the spatial organization context of chromatin. Nevertheless, many underlying concepts of impact of the chromatin organization on perpetuation of multiple mutations and on propagation of chromosomal aberrations remain to be investigated in detail. Genesis of genome instabilities from accumulation of multiple mutations that drive tumorigenesis is increasingly becoming a focal theme in cancer studies. This review focuses on structural alterations evolve to raise a variety of genome instabilities that are manifested at the nucleotide, gene or sub-chromosomal, and whole chromosome level of genome. Here we explore an underlying connection between genome instability and cancer in the light of genome architecture. This review is limited to studies directed towards spatial organizational aspects of origin and propagation of aberrations into genetically unstable tumors.

Keywords:
Nuclear architecture, spatial organization, chromatin structure, chromosomal aberrations, stem cells, genome instability, carcinogenesis

The Frequency of Proliferative Stromal Cells in Adipose Tissue Varies Between Inbred Mouse Strains

1 Apr 2009 04:56:33 GMT

Journal:
2009 Vol. 5 (1): p23-29

Published on:
Apr, 2009

Author(s):
Mo J, Srour EF, Rosen ED

Abstract:
Stromal cells derived from adipose tissue (ASCs) can proliferate as undifferentiated cells with a fibroblast-like morphology in cell culture, or can be induced to differentiate into a variety of cell types including, adipipogenic, myogenic, neurogenic, osteogenic, chondrogenic and hepatic cells. There is increasing interest to understand the factors controlling the proliferation of ASCs since these cells might provide a readily available source of autologous stem/progenitor cells for cell therapy applications. To explore potential genetic factors that modify the properties of ASCs, we tried to identify relevant properties of ASCs that differ between inbred mouse strains. Plating cells in a modified colony forming assay indicates that the percentage of high proliferative cells among ASCs differs more than 2-fold between 129x1/svj and C57Bl/6J mice. The identification of genetic factors affecting the proliferative capacity of stem cell populations could improve the efficacy of cell therapy.

Keywords:
adipose stromal cell; stem cell, mouse, cell proliferation, strain difference

Establishment of a rat model of myocardial infarction with a high survival rate: A suitable model for evaluation of efficacy of stem cell therapy

1 Apr 2009 04:56:33 GMT

Journal:
2009 Vol. 5 (1): p30-36

Published on:
Apr, 2009

Author(s):
Garikipati Venkata Naga Srikanth, Prem Prakash, Naresh Kumar Tripathy, Madhu Dikshit, Soniya Nityanand

Abstract:
The most common rat model of myocardial infarction (MI) is by ligation of left anterior descending (LAD) coronary artery but it is associated with high mortality and large variations in the infarct size. We evolved certain innovations/modifications in the existing technique including immobilization of the heart without exteriorization, identification of the LAD by pressing it proximal to the site of ligation by an ear-bud, and subsequently its ligation 8 mm from its origin, no touch technique of the lungs during surgery, removal of air from the chest cavity prior to its closure using an in-house tubing, and deflation of the lungs before extubation. We induced MI in 24 Sprague- Dawley (SD) rats using these modifications and carried out post-MI evaluation of hemodynamic parameters, serum cardiac enzymes and histological studies upto 90 days using 13 sham operated and 3 healthy SD rats as controls. Three of the 24 rats (13%) died <24 hours of MI, but thereafter no mortality was observed till the follow-up period of 90 days. The infarct size was consistent in all the rats (21±4% of left ventricular area). This model with low early and no long-term mortality may be suitable for studying efficacy of stem cell therapy in MI, where a follow-up of at least 13 weeks is required to assess myocardial regeneration.

Keywords:
Rat Model, Myocardial Infarction, Innovations in LAD Ligation, High Survival Rate, Stem Cell Therapy

Human Fallopian tube as a novel source of multipotent stem cells with potential for islet neogenesis

1 Apr 2009 04:56:33 GMT

Journal:
2009 Vol. 5 (1): p37-42

Published on:
Apr, 2009

Author(s):
Kadam SS, Patki SM, Bhonde RR

Abstract:
Presence of stem cells in the female genital tract has been reported; however stem cell status of Fallopian tube remains unexplored. In the present study, we show for the first time an existence of stem cells in a Fallopian tube. A pure population of mesenchymal like cells was obtained from the Fallopian tube samples from patients undergoing hysterectomy. The immunocytochemistry of these cells revealed the presence of classical mesenchymal stem cell markers like smooth muscle actin, vimetin, nestin, desmin, CD44, CD90 and CD117. These Fallopian Tube derived Mesenchymal stem cells could be induced to differentiate into adipocytes, chondrocytes, osteocytes, neuronal and pancreatic lineage under the influence of lineage specific differentiation cocktails. Such documentation of multipotent stem cells in a Fallopian tube may be of significance for instant repair of the tract as and when necessary so as to assist uninterrupted transport of eggs for possible fertilization thus facilitating reproduction.

Keywords:
Fallopian tube, Mesenchymal stem cells, multipotent differentiation