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Abstract
PURPOSE OF REVIEW One of the most common diseases of the tympanic membrane is a perforation, and tympanoplasty is one of the more common procedures in otolaryngology. Tympanic membrane regeneration and bioengineering aim to improve the success rate of the procedure, increase the availability of different scaffolds and provide innovative tools that will simplify the surgical technique and make it accessible for surgeons with varying expertise level. This review aims to raise awareness of current tissue engineering developments in tympanic membrane regeneration and how they may augment current clinical practices. We focus here on achievements in tympanic membrane cell cultures and on innovations in development of new scaffolds and growth factors that enhance regeneration of patient's native tympanic membranes. RECENT FINDINGS In recent years, great achievements were reached in the field of tympanic membrane regeneration in the three hallmarks of bioengineering: cells, scaffolds and bioactive molecules. New techniques for modeling normal tympanic membrane proliferation were developed, as well as for isolation and expansion of normal tympanic membrane keratinocytes from miniature samples of scarred tissue. Ongoing clinical trials aim to seal the perforation by applying different scaffolds infiltrated by growth factors on the tympanic membrane. SUMMARY Research efforts in tympanic membrane regeneration continue to seek the ideal single tissue-engineered substitute. Recent advances in tympanic membrane bioengineering include new types of scaffolds that may augment and provide a safe and effective alternative to the current gold-standard autograft. New bioactive molecules may simplify the surgical procedure and reduce surgical time by augmenting the native tympanic membrane regeneration. Several groups of bioengineering scientists and neurotologists are continuing to move forward and develop new strategies, seeking to create a fully functional tissue-engineered tympanic membrane.
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Sonam S, Srnak JA, Perry KJ, Henry JJ. Molecular markers for corneal epithelial cells in larval vs. adult Xenopus frogs. Exp Eye Res 2019; 184:107-125. [PMID: 30981716 DOI: 10.1016/j.exer.2019.04.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 04/08/2019] [Indexed: 12/14/2022]
Abstract
Corneal Epithelial Stem Cells (CESCs) and their proliferative progeny, the Transit Amplifying Cells (TACs), are responsible for maintaining the integrity and transparency of the cornea. These stem cells (SCs) are widely used in corneal transplants and ocular surface reconstruction. Molecular markers are essential to identify, isolate and enrich for these cells, yet no definitive CESC marker has been established. An extensive literature survey shows variability in the expression of putative CESC markers among vertebrates; being attributed to species-specific variations, or other differences in developmental stages of these animals, approaches used in these studies and marker specificity. Here, we expanded the search for CESC markers using the amphibian model Xenopus laevis. In previous studies we found that long-term label retaining cells (suggestive of CESCs and TACs) are present throughout the larval basal corneal epithelium. In adult frogs, these cells become concentrated in the peripheral cornea (limbal region). Here, we used immunofluorescence to characterize the expression of nine proteins in the corneas of both Xenopus larvae and adults (post-metamorphic). We found that localization of some markers change between larval and adult stages. Markers such as p63, Keratin 19, and β1-integrin are restricted to basal corneal epithelial cells of the larvae. After metamorphosis their expression is found in basal and intermediate layer cells of the adult frog corneal epithelium. Another protein, Pax6 was expressed in the larval corneas, but surprisingly it was not detected in the adult corneal epithelium. For the first time we report that Tcf7l2 can be used as a marker to differentiate cornea vs. skin in frogs. Tcf7l2 is present only in the frog skin, which differs from reports indicating that the protein is expressed in the human cornea. Furthermore, we identified the transition between the inner, and the outer surface of the adult frog eyelid as a key boundary in terms of marker expression. Although these markers are useful to identify different regions and cellular layers of the frog corneal epithelium, none is unique to CESCs or TACs. Our results confirm that there is no single conserved CESC marker in vertebrates. This molecular characterization of the Xenopus cornea facilitates its use as a vertebrate model to understand the functions of key proteins in corneal homeostasis and wound repair.
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Affiliation(s)
- Surabhi Sonam
- Department of Cell and Developmental Biology, University of Illinois, 601 S. Goodwin Avenue, Urbana, IL, 61801, USA
| | - Jennifer A Srnak
- Department of Cell and Developmental Biology, University of Illinois, 601 S. Goodwin Avenue, Urbana, IL, 61801, USA
| | - Kimberly J Perry
- Department of Cell and Developmental Biology, University of Illinois, 601 S. Goodwin Avenue, Urbana, IL, 61801, USA
| | - Jonathan J Henry
- Department of Cell and Developmental Biology, University of Illinois, 601 S. Goodwin Avenue, Urbana, IL, 61801, USA.
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Liu JY, Hafner J, Dragieva G, Burg G. Bioreactor Microcarrier Cell Culture System (Bio-MCCS) for Large-Scale Production of Autologous Melanocytes. Cell Transplant 2017; 13:809-16. [PMID: 15690983 DOI: 10.3727/000000004783983422] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Restoration of cutaneous pigmentation can be achieved in stable vitiligo by autologous cultured melanocyte transplantation. It was the goal of this study to construct a bioreactor microcarrier cell culture system (Bio-MCCS) to produce autologous melanocytes in large scale. In this Bio-MCCS, porcine gelatin microbeads were used as microcarriers, spinning bottle as fermented tank. Autologous melanocytes were able to attach to and proliferate on the gelatin microbeads in serum-free melanocyte medium in the Bio-MCCS, reaching up to 24-fold the cells seeded on day 15 (MTT assay). These autologous melanocytes cultured on gelatin microbeads could leave the microbeads and proliferate on the bottom of tissue culture flasks. Although Pluronic F68 has been widely used to protect animal cells from hydrodynamic stress in animal cell bioreactors, Pluronic F68 at a concentration of 0.25–1.0% showed no significant protective effects on the autologous melanocytes cultured on the microbeads and subjected to mechanical stress in the Bio-MCCS. This Bio-MCCS using porcine gelatin microbeads as microcarriers enabled large-scale production of autologous mela-nocytes, offering a potential treatment for large-area stable vitiligo by direct administration of the melanocytes cultured on the gelatin microbeads to the vitiliginous site.
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Affiliation(s)
- Jin Yu Liu
- Department of Dermatology, University Hospital of Zurich, Zurich, Switzerland
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Chua AWC, Khoo YC, Tan BK, Tan KC, Foo CL, Chong SJ. Skin tissue engineering advances in severe burns: review and therapeutic applications. BURNS & TRAUMA 2016; 4:3. [PMID: 27574673 PMCID: PMC4963933 DOI: 10.1186/s41038-016-0027-y] [Citation(s) in RCA: 148] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 01/11/2016] [Indexed: 01/13/2023]
Abstract
Current advances in basic stem cell research and tissue engineering augur well for the development of improved cultured skin tissue substitutes: a class of products that is still fraught with limitations for clinical use. Although the ability to grow autologous keratinocytes in-vitro from a small skin biopsy into sheets of stratified epithelium (within 3 to 4 weeks) helped alleviate the problem of insufficient donor site for extensive burn, many burn units still have to grapple with insufficient skin allografts which are used as intermediate wound coverage after burn excision. Alternatives offered by tissue-engineered skin dermal replacements to meet emergency demand have been used fairly successfully. Despite the availability of these commercial products, they all suffer from the same problems of extremely high cost, sub-normal skin microstructure and inconsistent engraftment, especially in full thickness burns. Clinical practice for severe burn treatment has since evolved to incorporate these tissue-engineered skin substitutes, usually as an adjunct to speed up epithelization for wound closure and/or to improve quality of life by improving the functional and cosmetic results long-term. This review seeks to bring the reader through the beginnings of skin tissue engineering, the utilization of some of the key products developed for the treatment of severe burns and the hope of harnessing stem cells to improve on current practice.
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Affiliation(s)
- Alvin Wen Choong Chua
- Singapore General Hospital, Department of Plastic, Reconstructive and Aesthetic Surgery, 20 College Road, Academia Level 4, Singapore, 169845 Singapore ; Singapore General Hospital, Skin Bank Unit, Block 4 Level 3 Room 15, Outram Road, Singapore, 169608 Singapore ; Transplant Tissue Centre, c/o Skin Bank Unit, Singapore General Hospital, Block 4 Level 3 Room A7, Outram Road, Singapore, 169608 Singapore
| | - Yik Cheong Khoo
- Singapore General Hospital, Skin Bank Unit, Block 4 Level 3 Room 15, Outram Road, Singapore, 169608 Singapore ; Transplant Tissue Centre, c/o Skin Bank Unit, Singapore General Hospital, Block 4 Level 3 Room A7, Outram Road, Singapore, 169608 Singapore
| | - Bien Keem Tan
- Singapore General Hospital, Department of Plastic, Reconstructive and Aesthetic Surgery, 20 College Road, Academia Level 4, Singapore, 169845 Singapore ; Singapore General Hospital, Skin Bank Unit, Block 4 Level 3 Room 15, Outram Road, Singapore, 169608 Singapore ; Transplant Tissue Centre, c/o Skin Bank Unit, Singapore General Hospital, Block 4 Level 3 Room A7, Outram Road, Singapore, 169608 Singapore
| | - Kok Chai Tan
- Singapore General Hospital, Department of Plastic, Reconstructive and Aesthetic Surgery, 20 College Road, Academia Level 4, Singapore, 169845 Singapore ; Singapore General Hospital, Skin Bank Unit, Block 4 Level 3 Room 15, Outram Road, Singapore, 169608 Singapore
| | - Chee Liam Foo
- Singapore General Hospital, Department of Plastic, Reconstructive and Aesthetic Surgery, 20 College Road, Academia Level 4, Singapore, 169845 Singapore ; Singapore General Hospital, Skin Bank Unit, Block 4 Level 3 Room 15, Outram Road, Singapore, 169608 Singapore
| | - Si Jack Chong
- Singapore General Hospital, Department of Plastic, Reconstructive and Aesthetic Surgery, 20 College Road, Academia Level 4, Singapore, 169845 Singapore ; Singapore General Hospital, Skin Bank Unit, Block 4 Level 3 Room 15, Outram Road, Singapore, 169608 Singapore ; Transplant Tissue Centre, c/o Skin Bank Unit, Singapore General Hospital, Block 4 Level 3 Room A7, Outram Road, Singapore, 169608 Singapore
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Sivakumar M, Dineshshankar J, Sunil PM, Nirmal RM, Sathiyajeeva J, Saravanan B, Senthileagappan AR. Stem cells: An insight into the therapeutic aspects from medical and dental perspectives. J Pharm Bioallied Sci 2015; 7:S361-71. [PMID: 26538878 PMCID: PMC4606620 DOI: 10.4103/0975-7406.163453] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The recent advancements in the field of stem cell (SC) biology have increased the hope of achieving the definitive treatments for the diseases which are now considered incurable such as diabetes, Parkinson's disease and other chronic long standing conditions. To achieve this possibility, it is necessary to understand the basic concepts of SC biology to utilize in various advanced techniques of regenerative medicine including tissue engineering and gene therapy. This article highlights the types of SCs available and their therapeutic capacity in regenerative medical and dental fields.
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Affiliation(s)
- Muniapillai Sivakumar
- Department of Oral Pathology and Microbiology, Madha Dental College and Hospital, Chennai, Tamil Nadu, India
| | - Janardhanam Dineshshankar
- Department of Oral Pathology and Microbiology, Vivekanandha Dental College for Women, Tiruchengode, Namakkal, Tamil Nadu, India
| | - P M Sunil
- Department of Oral Pathology and Microbiology, Sree Anjaneya Institute of Dental Sciences, Calicut, Kerala, India
| | - R Madhavan Nirmal
- Department of Oral Pathology and Microbiology, Rajah Muthiah Dental College and Hospital, Annamalai University, Chidambaram, Tamil Nadu, India
| | - J Sathiyajeeva
- Department of Oral Pathology and Microbiology, Thai Moogambigai Dental College and Hospital, Chennai, Tamil Nadu, India
| | - Balasubramanian Saravanan
- Department of Oral and Maxillofacial Surgery, Madha Dental College and Hospital, Kundrathur, Chennai, Tamil Nadu, India
| | - A R Senthileagappan
- Department of Pedodontics, Chettinad Dental College and Research Institute, Chettinad Health City, Chennai, Tamil Nadu, India
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Calenic B, Greabu M, Caruntu C, Tanase C, Battino M. Oral keratinocyte stem/progenitor cells: specific markers, molecular signaling pathways and potential uses. Periodontol 2000 2015; 69:68-82. [DOI: 10.1111/prd.12097] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/11/2015] [Indexed: 12/18/2022]
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Stem cells of the skin and cornea: their clinical applications in regenerative medicine. Curr Opin Organ Transplant 2013; 16:83-9. [PMID: 21150608 DOI: 10.1097/mot.0b013e32834254f1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW The use of stem cells is of great interest for the treatment of various pathologies and ultimately for the restoration of organ function. Progress pointing towards future treatments of skin and corneal epithelial stem cell defects are reviewed, including the transplantation of living tissue-engineered substitutes. RECENT FINDINGS This article focuses on substitutes optimized for permanent replacement of skin and cornea. New skin substitutes for burn care are currently under development. More complex tissue-engineered skin substitutes in which stroma, adipose tissue, capillaries, and neurons are combined with the epithelium are being developed. Some dermal/epidermal substitutes have been applied to the treatment of patients. Cultured corneal epithelial cells have been characterized and more complete corneal substitutes are being designed. Long-term clinical results on the transplantation of cultured corneal stem cells for the treatment of limbal stem cell deficiency have been reported. SUMMARY Advances in tissue engineering for the development of substitutes that will benefit patients suffering from skin or corneal stem cell deficiencies are reviewed. These products are often a combination of cells, scaffolds and other factors. Key considerations in the development of corneal and skin substitutes for clinical applications are discussed.
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Zellmer S, Surovoy A, Gaunitz F, Salvetter J, Gebhardt R, Reissig D. Transfection of normal human epidermal keratinocytes with lipid/dna complexes in vitro. J Liposome Res 2012; 11:43-54. [PMID: 19530918 DOI: 10.1081/lpr-100103169] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Highly proliferative normal human epidermal keratinocytes (NHK) were isolated from human foreskin biopsies, cultivated in serum-free medium and characterized by flow cytometry. The expression of cytokeratin 19, cytokeratin 14 and vimentin indicated that the suspension contained a high percentage of undifferentiated cells of the basal epidermal layer. The NHK were transfected in vitro with lipid/DNA complexes made of Effectene or Lipofectamine and different reporter genes. The transfection efficiency of Effectene/DNA complexes was 20fold higher compared to Lipofectamine. Transfected keratinocytes continued to grow and developed within 2 weeks a cellular multilayer (3-D culture). Areas of transfected cells were detected within this layer.
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Affiliation(s)
- S Zellmer
- Institute of Biochemistry, Medical Faculty, University Leipzig, Leipzig, D-04103, Germany
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Gauglitz GG, Zedler S, von Spiegel F, Fuhr J, von Donnersmarck GH, Faist E. Functional characterization of cultured keratinocytes after acute cutaneous burn injury. PLoS One 2012; 7:e29942. [PMID: 22359539 PMCID: PMC3281018 DOI: 10.1371/journal.pone.0029942] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2011] [Accepted: 12/08/2011] [Indexed: 11/18/2022] Open
Abstract
Background In addition to forming the epithelial barrier against the outside environment keratinocytes are immunologically active cells. In the treatment of severely burned skin, cryoconserved keratinocyte allografts gain in importance. It has been proposed that these allografts accelerate wound healing also due to the expression of a favourable - keratinocyte-derived - cytokine and growth factor milieu. Methods In this study the morphology and cytokine expression profile of keratinocytes from skin after acute burn injury was compared to non-burned skin. Skin samples were obtained from patients after severe burn injury and healthy controls. Cells were cultured and secretion of selected inflammatory mediators was quantified using Bioplex Immunoassays. Immunohistochemistry was performed to analyse further functional and morphologic parameters. Results Histology revealed increased terminal differentiation of keratinocytes (CK10, CK11) in allografts from non-burned skin compared to a higher portion of proliferative cells (CK5, vimentin) in acute burn injury. Increased levels of IL-1α, IL-2, IL-4, IL-10, IFN-γ and TNFα could be detected in culture media of burn injury skin cultures. Both culture groups contained large amounts of IL-1RA. IL-6 and GM-CSF were increased during the first 15 days of culture of burned skin compared to control skin. Levels of VEGF, FGF-basic, TGF-ß und G-CSF were high in both but not significantly different. Cryoconservation led to a diminished mediator synthesis except for higher levels of intracellular IL-1α and IL-1ß. Conclusion Skin allografts from non-burned skin show a different secretion pattern of keratinocyte-derived cytokines and inflammatory mediators compared to keratinocytes after burn injury. As these secreted molecules exert auto- and paracrine effects and subsequently contribute to healing and barrier restoration after acute burn injury therapies affecting this specific cytokine/growth factor micromilieu could be beneficial in burned patients.
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Affiliation(s)
- Gerd G Gauglitz
- Department of Dermatology and Allergy, Ludwig-Maximilian University, Munich, Germany.
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Harun MHN, Sepian SN, Chua KH, Ropilah AR, Abd Ghafar N, Che-Hamzah J, Bt Hj Idrus R, Annuar FH. Human forniceal region is the stem cell-rich zone of the conjunctival epithelium. Hum Cell 2011; 26:35-40. [PMID: 21748521 DOI: 10.1007/s13577-011-0025-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Accepted: 06/15/2011] [Indexed: 12/17/2022]
Abstract
The anterior surface of the eye is covered by several physically contiguous but histologically distinguishable epithelia overlying the cornea, limbus, bulbar conjunctiva, fornix conjunctiva, and palpebral conjunctiva. The self-renewing nature of the conjunctival epithelia makes their long-term survival ultimately dependent on small populations of stem cells. Hence, the objective of this study was to investigate the expression of the stem cell genes Sox2, OCT4, NANOG, Rex1, NES, and ABCG2 in cultured human conjunctival epithelium from different conjunctival zones, namely, the bulbar, palpebral and fornix zones. Three samples were taken from patients with primary pterygium and cataract (age range 56-66 years) who presented to our eye clinic at the UKM Medical Centre. The eye was examined with slit lamp to ensure there was no underlying ocular surface diseases and glaucoma. Conjunctival tissue was taken from patients who underwent a standard cataract or pterygium operation as a primary procedure. Tissues were digested, cultured, and propagated until an adequate number of cells was obtained. Total RNA was extracted and subjected to expression analysis of conjunctival epithelium genes (KRT4, KRT13, KRT19) and stem cell genes (Sox2, OCT4, NANOG, Rex1, NES, ABCG2) by reverse transcriptase-PCR and 2% agarose gel electrophoresis. The expression of Sox2, OCT4, and NANOG genes were detected in the fornical cells, while bulbar cells only expressed Sox2 and palpebral cells only expressed OCT4. Based on these results, the human forniceal region expresses a higher number of stem cell genes than the palpebral and bulbar conjunctiva.
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Affiliation(s)
- Mohd Hairul Nizam Harun
- Department of Ophthalmology, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latif, 56000, Kuala Lumpur, Malaysia
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Siprashvili Z, Nguyen NT, Bezchinsky MY, Marinkovich MP, Lane AT, Khavari PA. Long-term type VII collagen restoration to human epidermolysis bullosa skin tissue. Hum Gene Ther 2011; 21:1299-310. [PMID: 20497034 DOI: 10.1089/hum.2010.023] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In spite of advances in the molecular diagnosis of recessive dystrophic epidermolysis bullosa (RDEB), an inherited blistering disease due to a deficiency of type VII collagen at the basement membrane zone (BMZ) of stratified epithelium, current therapy is limited to supportive palliation. Gene delivery has shown promise in short-term experiments; however, its long-term sustainability through multiple turnover cycles in human tissue has awaited confirmation. To characterize approaches for long-term genetic correction, retroviral vectors were constructed containing long terminal repeat-driven full-length and epitope-tagged COL7A1 cDNA and evaluated for durability of type VII collagen expression and function in RDEB skin tissue regenerated on immune-deficient mice. Type VII collagen expression was maintained for 1 year in vivo, or over 12 epidermal turnover cycles, with no abnormalities in skin morphology or self-renewal. Type VII collagen restoration led to correction of RDEB disease features, including reestablishment of anchoring fibrils at the BMZ. This approach confirms durably corrective and noninjurious gene delivery to long-lived epidermal progenitors and provides the foundation for a human clinical trial of ex vivo gene delivery in RDEB.
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Affiliation(s)
- Zurab Siprashvili
- Veterans Affairs Palo Alto Healthcare System, Palo Alto, CA 94304, USA
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Knop E, Knop N, Millar T, Obata H, Sullivan DA. The international workshop on meibomian gland dysfunction: report of the subcommittee on anatomy, physiology, and pathophysiology of the meibomian gland. Invest Ophthalmol Vis Sci 2011; 52:1938-78. [PMID: 21450915 PMCID: PMC3072159 DOI: 10.1167/iovs.10-6997c] [Citation(s) in RCA: 683] [Impact Index Per Article: 52.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Accepted: 03/23/2011] [Indexed: 12/15/2022] Open
Affiliation(s)
- Erich Knop
- Ocular Surface Center Berlin, Department for Cell and Neurobiology, Center for Anatomy, Charité-Universitätsmedizin Berlin, Berlin, Germany
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Chang SE, Kim Pak Y, Lee HW, Choi JH, Jeong EJ, Choi SH, Chang HW, Chung YS, Kim SY. Reduced mitochondrial properties in putative progenitor/stem cells of human keratinocytes. Ann Dermatol 2009; 21:364-8. [PMID: 20523825 DOI: 10.5021/ad.2009.21.4.364] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2009] [Revised: 05/08/2009] [Accepted: 05/11/2009] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND The characterization of progenitor/keratinocyte stem cells (KSC) remains an unachieved goal. A previous study showed that rapid adhering cells to collagen IV had the characteristics of putative progenitor/KSCs. OBJECTIVE The purpose of this study was to investigate the genetic expression of rapid adhering cells compared to non adhering cells to determine the characteristic of KSCs. METHODS We isolated rapid adhering cells representative of KSCs from non adhering cells representative of transient amplifying cells. In addition, we differentiated cells from human tonsilar keratinocytes utilizing the adhering capability of the KSCs to collagen IV. Annealing control primer based differentially displayed polymerase chain reaction (PCR) was performed as well as Western blot analysis. RESULTS The levels of mitochondria-related gene expression were low in the rapid adhering cells compared to the non adhering cells. Mitochondrial complex I, COX IV, peroxiredoxins (I, II and IV) and mitochondrial membrane potential were all low in the rapid adhering cells compared to the non adhering cells. CONCLUSION Using an adhesion method on human collagen IV-coated plates, our results suggest that reduced mitochondrial function may be an important characteristic of KSCs.
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Affiliation(s)
- Sung-Eun Chang
- Department of Dermatology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
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Guerra L, Dellambra E, Panacchia L, Paionni E. Tissue Engineering for Damaged Surface and Lining Epithelia: Stem Cells, Current Clinical Applications, and Available Engineered Tissues. TISSUE ENGINEERING PART B-REVIEWS 2009; 15:91-112. [DOI: 10.1089/ten.teb.2008.0418] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Liliana Guerra
- Tissue Engineering and Cutaneous Physiopathology Laboratory, Istituto Dermopatico dell'Immacolata-IRCCS, Rome, Italy
| | - Elena Dellambra
- Tissue Engineering and Cutaneous Physiopathology Laboratory, Istituto Dermopatico dell'Immacolata-IRCCS, Rome, Italy
| | - Laura Panacchia
- Tissue Engineering and Cutaneous Physiopathology Laboratory, Istituto Dermopatico dell'Immacolata-IRCCS, Rome, Italy
| | - Emanuel Paionni
- Tissue Engineering and Cutaneous Physiopathology Laboratory, Istituto Dermopatico dell'Immacolata-IRCCS, Rome, Italy
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Spiekstra SW, Breetveld M, Rustemeyer T, Scheper RJ, Gibbs S. Wound-healing factors secreted by epidermal keratinocytes and dermal fibroblasts in skin substitutes. Wound Repair Regen 2008; 15:708-17. [PMID: 17971017 DOI: 10.1111/j.1524-475x.2007.00280.x] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Full-skin substitutes, epidermal substitutes, and dermal substitutes are currently being used to heal deep burns and chronic ulcers. In this study, we investigated which wound-healing mediators are released from these constructs and whether keratinocyte-fibroblast interactions are involved. Autologous skin substitutes were constructed from human keratinocytes, fibroblasts, and acellular donor dermis. Full-thickness skin was used to represent an autograft. Secretion of wound-healing mediators was investigated by means of protein array, enzyme-linked immunosorbent assay, neutralizing antibodies, and conditioned culture supernatants. Full-skin substitutes and autografts produce high amounts of inflammatory/angiogenic mediators (IL-6, CCL2, CXCL1, CXCL8, and sST2). Epidermal and dermal substitutes produced less of these proteins. Epidermal-derived proinflammatory cytokines interleukin-1alpha (IL-1alpha) and tumor necrosis factor-alpha (TNF-alpha) were found to mediate synergistically the secretion of these wound-healing mediators (with the exception of sST2) from fibroblasts in dermal substitutes. The secretion of proinflammatory cytokines (IL-1alpha, TNF-alpha), chemokine/mitogen (CCL5) and angiogenic factor (vascular endothelial growth factor) by epidermal substitutes and tissue remodeling factors (tissue inhibitor of metalloproteinase-2, hepatocyte growth factor) by dermal substitutes was not influenced by keratinocyte-fibroblast interactions. The full-skin substitute has a greater potential to stimulate wound healing than epidermal or dermal substitutes. Both epidermal-derived IL-1alpha and TNF-alpha are required to trigger the release of dermal-derived inflammatory/angiogenic mediators from skin substitutes.
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Affiliation(s)
- Sander W Spiekstra
- Department of Dermatology, VU University Medical Centre, Amsterdam, The Netherlands
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Barrandon Y. Crossing boundaries: stem cells, holoclones, and the fundamentals of squamous epithelial renewal. Cornea 2007; 26:S10-2. [PMID: 17881908 DOI: 10.1097/ico.0b013e31814b14de] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Renewal of stratified squamous epithelia, eg, the epidermis, the esophagus, or the epithelia lining the oral cavity, normally depends on the presence of keratinocyte stem cells that are thoroughly distributed in the epithelial basal layer. It is commonly thought that stem cells divide asymmetrically and generate transient amplifying cells. In turn, the latter generate postmitotic cells, which will replace the terminally differentiated cells that constantly slough off the epithelial surface. In this model, each stem cell only renews a tiny epithelial column, even if it has the capacity to generate a large amount of epithelium, a property important during wound healing. Interestingly, the cornea is an exception among stratified epithelia, because it does not contain stem cells but rather relies on the centripetal migration of transient amplifying cells generated by stem cells dividing occasionally and located at the limbus, the transition zone of the cornea with the conjunctiva. It is unclear which evolutionary advantage an epithelium with a rapid turn over has gained through the development of such a mechanism. Understanding why and how the cornea has evolved differently from all other stratified epithelia is certainly a major challenge in epithelial stem cell biology.
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Affiliation(s)
- Yann Barrandon
- Laboratory of Stem Cell Dynamics, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
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Chua AWC, Ma DR, Song IC, Phan TT, Lee ST, Song C. In vitro evaluation of fibrin mat and Tegaderm wound dressing for the delivery of keratinocytes--implications of their use to treat burns. Burns 2007; 34:175-80. [PMID: 18029101 DOI: 10.1016/j.burns.2007.07.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2007] [Accepted: 07/24/2007] [Indexed: 10/22/2022]
Abstract
The effectiveness of fibrin mat and Tegaderm delivery systems to maintain clonogenic keratinocytes in culture were evaluated using in vitro methods. A fibrin mat was found to provide a culture environment that is conducive for the proliferation of keratinocytes and supporting their ability to form colonies of good growth potential in vitro. This confirms that the fibrin mat is a good delivery system for cultured epithelial autograft (CEA). In our unit, fibrin-CEA is limited only for the treatment of severe burns due to the high cost of fibrin glue. However, this substrate is able to maintain the regenerative properties of the CEA which is crucial for the treatment of extensive and full thickness burns. Tegaderm, a cost-effective polyurethane wound dressing is able to support keratinocyte cell growth but at a slower rate and with fewer colonies formed compared to the fibrin system. This suggests that Tegaderm can be an alternative approach of delivering autologous cells, limited to treat chronic wounds and less extensive burns. The use of simple and relatively inexpensive bench techniques can potentially serve as a quality control to check for keratinocytes cultured and delivered to every patient in the clinical setting.
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Affiliation(s)
- A W C Chua
- Skin Bank Unit, Singapore General Hospital, Singapore.
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18
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Alfano C, Chiummariello S, Fioramonti P, Innocenzi D, Scuderi N. Ultrastructural study of autologous cultivated conjunctival epithelium. Ophthalmic Surg Lasers Imaging Retina 2006; 37:378-82. [PMID: 17017197 DOI: 10.3928/15428877-20060901-04] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND OBJECTIVE This report is one of the first in the literature on the attempted cultivation and clinical application of human conjunctival epithelium. The authors investigated the possibility of restoring severely damaged ocular surface with autologous cultivated conjunctival epithelium. PATIENTS AND METHODS The conjunctival cells needed for the experiment were harvested from six patients with oculopalpebral diseases. Confluent epithelial sheets were developed from each biopsy specimen. The new epithelium was then implanted on the patients' or donors' eye surface. RESULTS The histologic examination showed a pluristratified squamous non-keratinized epithelium lying on a basement membrane and with a lamina propria of well-vascularized connective tissue. Normal ultrastructural characteristics were evident on electron microscopy. CONCLUSION The cultivation of autologous conjunctival cells may be a good option for rapid and safe repair of large single or bilateral conjunctival defects, as an alternative to heterotopic or allogenic grafts.
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Affiliation(s)
- Carmine Alfano
- Department of Plastic and Reconstructive Surgery, University of Rome La Sapienza, Rome, Italy
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Fossum M, Lundberg F, Holmberg K, Schoumans J, Kratz G, Nordenskjöld A. Long-Term Culture of Human Urothelial Cells – A Qualitative Analysis. Cells Tissues Organs 2006; 181:11-22. [PMID: 16439815 DOI: 10.1159/000089965] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/11/2005] [Indexed: 11/19/2022] Open
Abstract
Today, in vitro culturing of autologous cells is an established method in the field of tissue reconstruction. It can be applied to urothelial cells and could have many clinical implications in urological reconstructive surgery. This development calls for quality controls concerning cells used for clinical treatment when cells are autotransplanted back to the patient. We have studied cultured cells in order to detect whether genetic or morphologic changes occur. Urothelial cells isolated from bladder lavage were cultured according to different protocols based on the presence or absence of feeder cells. Genetic studies were performed by means of karyotyping with standard G-banding and interphase fluorescent in situ hybridization (FISH) analyses. The morphology of these epithelial cells was judged as well as immunostaining for epithelial cell markers. In addition, to minimize the risk of feeder cell contamination, proliferation studies were performed on cultures including feeder cells that had been pretreated with different doses of mitomycin or radiation. In initial studies, when using feeder cells in each passage according to standard protocols, urothelial cells proliferated unfavourably after the fourth passage with increasing numbers of mouse cells as well as urothelial tetraploid cells. We could also show that urothelial cells from bladder lavage need feeder cells in order to establish primary cultures. Further propagation up to 14 passages was performed without feeder cells and the urothelial cells retained normal karyotypes. We also found that mitomycin treatment had its main effect on feeder cells during the first 2 h. When feeder cells were irradiated, 20 Gy was effective and no feeder cell contamination was seen. In conclusion, we found that a high standard of quality in urothelial cell culturing can be achieved with a careful culturing technique.
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Affiliation(s)
- Magdalena Fossum
- Department of Molecular Medicine, Karolinska University Hospital, SE-171 76 Stockholm, Sweden.
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20
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Abstract
Human epidermis consists of a stratified epithelium mainly composed of keratinocytes and relies on a stem cell compartment to undergo constant regeneration. Genetic mutations affecting the capacity of basal keratinocytes to adhere firmly to the epidermal basement membrane lead to severe, and very often lethal, blistering disorders known as epidermolysis bullosa. Gene therapy represents a promising potential treatment for these devastating inherited disorders. Human epidermal stem cells can be cultivated ex vivo and stably transduced with integrating gene transfer vectors, allowing genetic and, more important, phenotypic correction of the adhesion properties of keratinocytes. Here we will review some of the issues that need to be addressed to make gene therapy a realistic treatment for these disorders, such as (1) which cells should be targeted, (2) which approach (in vivo or ex vivo) should be chosen, and (3) which gene transfer vector (retrovirus, lentivirus, or integrating nonviral strategies) should be used for stable gene correction. In the last 10 years, many reports have shown that gene transfer approaches to target epidermal stem cells are feasible and able to restore the adhesion properties of primary keratinocytes from patients with epidermolysis bullosa. In addition, tremendous progress has been achieved in culturing epidermal stem cells and generating sheets of stratified epithelium for permanent coverage of full-thickness burns. Gene modification of stem cells in combination with advanced tissue-engineering techniques could therefore represent a realistic option for patients with epidermolysis bullosa.
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Affiliation(s)
- Stefano Ferrari
- Epithelial Stem Cell Research Centre, Veneto Eye Bank Foundation, 30122 Venice, Italy
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21
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Burillon C. [Other surgical therapies for cornea burns]. J Fr Ophtalmol 2005; 27:1191-6. [PMID: 15687935 DOI: 10.1016/s0181-5512(04)96294-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
With limbal stem cell and amniotic membrane transplantations, penetrating keratoplasty is the most important treatment of severe corneal burns. In the acute stage, re-epithelialization failure and resultant stromal ulceration can induce corneal perforation. A lamellar or a full-thickness patch graft is indicated in order to preserve the eyeball. For small perforations, tissue adhesive can be used. In the early reparative stage, keratoplasty has its place, but corneal vascularization is a major risk factor for graft rejection. Lamellar keratoplasty is preferred because it provides tectonic support. After several graft failures, a keratoprosthesis is the last solution for these bilaterally affected patients, but evisceration cannot be always avoided.
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Affiliation(s)
- C Burillon
- Service d'Ophtalmologie, Hôpital Edouard Herriot, 5, place d'Arsonval, 69437 Lyon cedex 03, France
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22
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Gagnoux-Palacios L, Hervouet C, Spirito F, Roques S, Mezzina M, Danos O, Meneguzzi G. Assessment of optimal transduction of primary human skin keratinocytes by viral vectors. J Gene Med 2005; 7:1178-86. [PMID: 15880606 DOI: 10.1002/jgm.768] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Genetically modified keratinocytes generate transplantable self-renewing epithelia suitable for delivery of therapeutic polypeptides. However, the variety of viral vectors and experimental conditions currently used make fragmented or contradictory the information on the transduction efficiency of the human primary keratinocytes. To compare the suitability of the most currently used viral vectors for efficient gene transfer to human keratinocytes, we have performed a comparative study using a panel of recombinant constructs. METHODS For each vector, the transduction efficiency and the persistence of the transgene expression were quantified by fluorescence microscopy and flow cytometry analysis of the infected cells. RESULTS We show that: (1) canine and human adenoviral vectors achieve a highly efficient but transient transduction of both primary and immortalized keratinocytes; (2) the adenovirus-associated virus (AAV) vectors transduce immortalized keratinocytes, albeit with a short-lived gene expression (<4 days), but fail to infect primary keratinocytes; and (3) under appropriate conditions, the oncoretroviral and lentiviral vectors can permanently transduce up to 100% of primary keratinocytes, but the highly clonogenic keratinocytes are more efficiently targeted by lentiviral vectors. CONCLUSIONS Therefore, AAV vectors are unsuitable to transduce primary keratinocytes, while human and canine adenoviral vectors appears to be appropriate to achieve short-term delivery of therapeutic products. Recombinant retroviruses provide sustained expression of the transgene, but the lentiviral vectors are the most suitable for ex vivo gene therapy because of their ability to transduce clonogenic primary keratinocytes.
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Ramaesh K, Ramaesh T, West JD, Dhillon B. Immunolocalisation of leukaemia inhibitory factor in the cornea. Eye (Lond) 2004; 18:1006-9. [PMID: 15060560 DOI: 10.1038/sj.eye.6701394] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
AIM Leukaemia inhibitory factor (LIF) is a pleotrophic cytokine expressed in a variety of cell types, and have shown to regulate stem cell proliferation, vascular genesis, inflammation, and immunity in various locations. Expression of LIF and its role in the cornea have not been studied previously. In this study, we examined the expression of LIF in the cornea. MATERIALS AND METHOD Immunohistochemistry was performed using polyclonal LIF antibodies, and Avidin-Biotin ABC complex on cultured human corneal epithelium corneal fibroblasts and wild-type murine corneal epithelium. RESULTS LIF was detected in the cytoplasm of murine corneal epithelium, cultured human corneal epithelium, and fibroblasts. The expression of LIF was mainly cytoplasmic. CONCLUSION LIF is expressed in the corneal epithelium and fibroblasts. It may have an important role in the maintenance of homeostasis of the corneal epithelium and cornea stroma. Further studies are necessary to elucidate the role of LIF in the cornea.
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Affiliation(s)
- K Ramaesh
- Tennent Institute of Ophthalmology, Gartnaval General Hospital 1053, Great Western Road, Glasgow, G12 0YN, UK.
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24
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Boulton M, Albon J. Stem cells in the eye. Int J Biochem Cell Biol 2004; 36:643-57. [PMID: 15010329 DOI: 10.1016/j.biocel.2003.10.013] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2003] [Revised: 10/24/2003] [Accepted: 10/29/2003] [Indexed: 12/21/2022]
Abstract
In the adult organism, all tissue renewal and regeneration depends ultimately on somatic stem cells, and the eye is no exception. The importance of limbal stem cells in the maintenance of the corneal epithelium has long been recognised, and such cells are now used clinically for repair of a severely damaged cornea. The slow cycling nature of lens epithelial cells and their ability to terminally differentiate into fiber cells are suggestive of a stem cell lineage. Furthermore, recent studies have identified progenitor cells in the retina and ocular vasculature which may have important implications in health and disease. Although the recent literature has become flooded with articles discussing aspects of stem cells in a variety of tissues our understanding of stem cell biology, especially in the eye, remains limited. For instance, there is no definitive marker for ocular stem cells despite a number of claims in the literature, the patterns of stem cell growth and amplification are poorly understood and the microenvironments important for stem cell regulation and differentiation pathways are only now being elucidated. A greater understanding of ocular stem cell biology is essential if the clinical potential for stem cells is to be realised. For instance; How do we treat stem cell deficiencies? How do we use stem cells to regenerate damaged retinal tissue? How do we prevent stem cell lineages contributing to retinal vascular disease? This review will briefly consider the principal stem cells in the mature eye but will focus in depth on limbal stem cells and corneal epithelium. It will further discuss their role in pathology and their potential for therapeutic intervention.
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Affiliation(s)
- Mike Boulton
- Cell and Molecular Biology Unit, School of Optometry and Vision Sciences, Cardiff University, Redwood Building, King Edward VII Avenue, Cathays Park, Cardiff CF10 3NB, Wales, UK.
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El-Ghalbzouri A, Lamme EN, van Blitterswijk C, Koopman J, Ponec M. The use of PEGT/PBT as a dermal scaffold for skin tissue engineering. Biomaterials 2004; 25:2987-96. [PMID: 14967531 DOI: 10.1016/j.biomaterials.2003.09.098] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2003] [Accepted: 09/18/2003] [Indexed: 11/22/2022]
Abstract
Human skin equivalents (HSEs) were engineered using biodegradable-segmented copolymer PEGT/PBT as a dermal scaffold. As control groups, fibroblast-populated de-epidermized dermis, collagen, fibrin and hybrid PEGT/PBT-collagen matrices were used. Two different approaches were used to generate full-thickness HSE. In the 1-step approach, keratinocytes were seeded onto the fibroblast-populated scaffolds and cultured at the air-liquid (A/L) interface. In the 2-step approach, fully differentiated epidermal sheets were transferred onto fibroblast-populated scaffolds and cultured at the A/L. In a 1-step procedure, keratinocytes migrated into the porous PEGT/PBT scaffold. This was prevented by incorporating fibroblast-populated collagen into the pores of the PEGT/PBT matrix or using the 2-step procedure. Under all experimental conditions, fully differentiated stratified epidermis and basement membrane was formed. Differences in K6, K16, K17, collagen type VII, laminin 5 and nidogen staining were observed. In HSE generated with PEGT/PBT, the expression of these keratins was higher, and the deposition of collagen type VII, laminin 5 and nidogen at the epidermal/matrix junction was retarded compared to control HSEs. Our results illustrate that the copolymer PEGT/PBT is a suitable scaffold for the 2-step procedure, whereas the incorporation of fibroblast-populated collagen or fibrin into the pores of the scaffold is required for the 1-step procedure.
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Migliaccio AR, Quarto R, Piacibello W. Cell therapy: filling the gap between basic science and clinical trials October 15-17, 2001, Rome, Italy. Stem Cells 2004; 21:348-56. [PMID: 12743329 DOI: 10.1634/stemcells.21-3-348] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Summarized here, and in forthcoming issues of, are the concepts that emerged at a recent international workshop on cell therapy organized by The Istituto Superiore di Sanità in Rome in collaboration with Istituto Dermatopatico dell'Immacolata, Rome; Istituto Nazionale Ricerca Cancro-Centro Biotecnologie Avanzate, Genova; and University G. D'Annunzio, Chieti. The meeting intent was to provide an overview of the most recent developments in cell therapy, the future perspectives for these clinical trials, and the regulatory issues they involve, as well as a progress report on the clinical protocols that have been approved up to now in Italy. The meeting included six scientific sessions (Immunotherapy, Epithelium, Osteoregeneration, Hematopoiesis, Future Perspectives, and Overview of the National and International Regulations) and involved lectures from Italian and foreign scientists.
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27
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Abstract
The "engineering" of a tissue implies that it can be constructed by assembling the necessary components. However, tissues are formed through an evolving, interactive process, not through a collection of parts. This chapter focuses on the biology of the progenitor cell, the native precursor to new tissue, and its role in neogenesis, or the de novo generation of functional tissue. We present a working hypothesis for the generation of parenchymal cell populations and use this hypothesis as a basis for analysis of three parenchymal populations, epidermal cells, hepatocytes of the liver, and pancreatic islets, with a view toward what impact this information will have on the development of cell therapies. By comparing developmental processes, response to injury and disease, and behavior in vitro, we conclude that the adult progenitor cell retains the potential for substantial growth and organ neogenesis and that its biological properties make it the cell of first choice for the engineering of tissues.
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28
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Bellini MH, Peroni CN, Bartolini P. Increases in weight of growth hormone‐deficient and immunodeficient (lit/scid) dwarf mice after grafting of hGH‐ secreting, primary human keratinocytes. FASEB J 2003; 17:2322-4. [PMID: 14525947 DOI: 10.1096/fj.03-0018fje] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Primary human keratinocytes, stably transduced with the human growth hormone (hGH) gene (under control of the retroviral LTR promoter) and selected via geneticin secreted as much as 7 microg hGH/106 cells/day. Their grafting onto immunodeficient dwarf mice (lit/scid) led to hGH levels in the circulation that did not go below 0.2-0.3 ng/ml during a 12 day period (peak value, 1.5 ng/ml at 4 h). This phenomenon was associated with a body weight increase of the grafted animals (0.060 g/animal/day) significantly higher (P<0.01) than that of controls (0.023 g/animal/day). This is the first report describing successful utilization of immunodeficient dwarf mice (lit/scid) in keratinocyte-based hGH gene therapy.
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29
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Ramaesh K, Dhillon B. Ex vivo expansion of corneal limbal epithelial/stem cells for corneal surface reconstruction. Eur J Ophthalmol 2003; 13:515-24. [PMID: 12948308 DOI: 10.1177/112067210301300602] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE The management of severe ocular surface disease due to limbal stem cell deficiency has changed dramatically. The concept of limbal stem cells, as the source of corneal epithelium revolutionised the therapeutic approach of ocular surface reconstruction. Deficiency of limbal stem cells results in blinding ocular surface diseases. Grafting viable limbal tissue, from either fellow healthy eye or a donor eye, with the resident stem cell population may replenish limbal stem cells and can restore the corneal surface to normality. Transplanting the limbal tissue can be achieved through a variety of procedures that include cadaveric keratolimbal allograft (KLAL), live or living related conjunctival limbal allograft (Ir-CLAL) and limbal autograft. Advances in tissue engineering techniques have offered a viable alternative to overcome the limitation of limbal tissue available for transplantation. Epithelial stem cells harvested from a small limbal biopsy can be expanded in vitro on a suitable carrier and then transplanted to the diseased cornea to successfully restore the corneal surface. This article is a chronological review of the important steps that brought ex vivo expanded stem cell transplantation in ocular, particularly corneal surface reconstruction. METHODS The MEDLINE data base was searched for the years 1966-2002, using key words cornea, cell culture, ex-vivo expansion, limbus, stem cell, ocular surface and transplantation. Several articles that were not found by MEDLINE search were taken from references from other articles. Inclusion or exclusion of article was based on the relevance to the subject. CONCLUSIONS Corneal epithelial reconstruction with ex vivo expanded limbal cells is a potential tool in ocular surface reconstruction, although the technique is currently investigational. Strategies to achieve conjunctival epithelial restoration and tear film replenishment will allow ophthalmic surgeons to truly reconstruct the ocular surface.
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Affiliation(s)
- K Ramaesh
- Princess Alexandra Eye Pavilion, Edinburgh, UK.
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30
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Kallos MS, Sen A, Behie LA. Large-scale expansion of mammalian neural stem cells: a review. Med Biol Eng Comput 2003; 41:271-82. [PMID: 12803291 DOI: 10.1007/bf02348431] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A relatively new approach to the treatment of neurodegenerative diseases is the direct use of neural stem cells (NSCs) as therapeutic agents. The expected demand for treatment from the millions of afflicted individuals, coupled with the expected demand from biotechnology companies creating therapies, has fuelled the need to develop large-scale culture methods for these cells. The rapid pace of discovery in this area has been assisted through the use of animal model systems, enabling many experiments to be performed quickly and effectively. This review focuses on recent developments in expanding human and murine NSCs on a large scale, including the development of new serum-free media and bioreactor protocols. In particular, engineering studies that characterise important scale-up parameters are examined, including studies examining the effects of long-term culture of NSCs in suspension bioreactors. In addition, recent advances in the human NSC system are reviewed, including techniques for the evaluation of NSC characteristics.
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Affiliation(s)
- M S Kallos
- Pharmaceutical Production Research Facility, Faculty of Engineering, University of Calgary, Calgary, Alberta, Canada
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Qian T, Hongreng Z, Zhongtao Z, Lei W, Guansen N, Ping S, Zihao L. Culture of rat keratinocytes with acellular pig dermis. BRITISH JOURNAL OF PLASTIC SURGERY 2003; 56:260-5. [PMID: 12859922 DOI: 10.1016/s0007-1226(03)00097-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
This study evaluated the growth rate and the cell activity of cultured keratinocytes on acellular pig dermis in order to develop a composite skin in vitro for burn injuries or other skin defects. Full thickness skin was cultivated from neonatal SD rats, and separated into epidermal layer and dermal layer with enzyme digestion. The keratinocytes were then seeded on the prepared acellular pig dermis soaked in the culture medium. The cultures were incubated and the growth status of keratinocytes on acellular pig dermis evaluated by phase contrast microscope, histological examination with hematoxylin-eosin staining and acridine orange staining, immunohistochemistry, observation of growth curve plotted by MTT colorimetry and analysis of changes in keratinocytes proliferation cycle with flow cytometer. Almost all keratinocytes anchored in 48-72 h, and most inosculated at days 6 and 7. The growth curve showed that the keratinocytes grew in logarithmic phase at days 3-6 after seeding. More than four layers of keratinocyte structure and the basement membrane between keratinocytes and porcine dermis were observed. Pancytokeratin was strongly positive in the cultured keratinocytes. Laminin and collagen IV were positive in the basement membrane. It is concluded that the cultured keratinocytes on acellular pig dermis grow well and the structure of composite skin which has been established is satisfactory.
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Affiliation(s)
- Tan Qian
- Department of Burns and Plastic Surgery, Zhongda Hospital, Southeast University, Nanjing, Jiangsu 210009, People's Republic of China
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Labský J, Dvoránková B, Smetana K, Holíková Z, Broz L, Gabius HJ. Mannosides as crucial part of bioactive supports for cultivation of human epidermal keratinocytes without feeder cells. Biomaterials 2003; 24:863-72. [PMID: 12485804 DOI: 10.1016/s0142-9612(02)00419-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Large-scale production of keratinocytes by cell culture is of interest for medical applications. Long-term cultivation of epidermal cells is presently possible with feeder cells, i.e. 3T3 fibroblasts with arrested mitosis, or with specially formulated culture medium. To define refinements for in vitro conditions, the analysis of the natural environment with growth-maintaining/stimulating factors can provide important clues. Cells with proliferative activity are located in the basal layer of the epidermis in close contact with a basement membrane. Employing lectin and reverse lectin histochemistry of skin, muscle fibers and feeder cells, we assumed that the interplay of mannose-binding sites of epidermal cells, detected by a labeled neoglycoprotein, with glycoligands in the feeder cell layer or basement membrane could trigger signaling with relevance for adhesion and growth regulation. Indeed, coating of polystyrene with mannose-containing neoglycoprotein mimicking a mannose-rich cell matrix enabled the cultivation of keratinocytes without feeder cells in a Ca(2+)-dependent manner in serum-containing culture medium. Following this experimental demonstration of specific binding of mannose residues as part of a neoglycoprotein controlled by testing sugar-free carrier protein and other substances, we next synthesized and tested biocompatible polymers. Attachment and proliferation of keratinocytes on the surface of these polymers compared favorably to control experiments using feeder cells. In conclusion, we suggest that these polymers are bioactive offering a perspective for keratinocyte cultivation without feeder cells.
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Affiliation(s)
- Jirí Labský
- Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic
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Abstract
The aim of this paper was to develop a GFP-expressing transgenic mouse model for the keratoepithelioplasty and to use this to follow the outcome of this form of graft, when placed on an inflamed corneal surface. Further aims were to characterize both the graft and the epithelial surface of the mouse and rat cornea using putative stem cell markers (P63 and Telomerase) and marker of cell differentiation (14-3-3 sigma). Keratepithelioplasty was carried out using a GFP transgenic mouse cornea as donor tissue. Fluorescent epithelial outgrowth from each keratepithelioplasty was scored and quantified. Donor corneal graft tissue was obtained from the paracentral region or the anatomical limbal region of murine corneas. Paracentral donor grafts (n = 20) consistently demonstrated a significant increase in proliferative potential compared to grafts obtained from the anatomical limbal region of the mouse cornea (n = 25) (P = 0.000, Mann-Whitney U). Correspondingly, P63 expression was maximal in the paracentral region of the mouse cornea, in keeping with the demonstrated increased proliferative potential of donor grafts harvested from this region of the cornea. The murine corneal epithelium demonstrated decreased rather than increased cellular layers at the limbal region, in contrast to that of the rat or human epithelium. In addition, as a general finding in all species tested, there was an apparent increase noted in P63 expression in basal corneal epithelial cells in regions that had increased cellular layers (limbus in humans and rats and the paracentral corneal region in the mouse). Epithelium, which had migrated from donor grafts onto recipient corneas, retained P63 expression for the period of time examined (up to 3 days postengraftment). In addition, the conjunctival surface of an injured conjunctivalized displayed an abnormal pattern of P63 expression. Telomerase expression was widespread throughout many layers of both the murine and rat corneal epithelium. In the mouse and rat corneal epithelium P63 expression was maximal in areas of increased proliferative potential. Its expression, however, was not confined to stem cells alone. Migrating cells from transplanted keratoepithelial grafts retained P63 expression at least in the early stages post-transplantation. Finally, damaged conjunctivalized corneas displayed an abnormal P63 expression pattern when compared to either normal conjunctiva or normal cornea.
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Affiliation(s)
- J E Moore
- Department of Ophthalmology, The Queen's University of Belfast, N. Ireland
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34
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Kedjarune U, Pongprerachok S, Arpornmaeklong P, Ungkusonmongkhon K. Culturing primary human gingival epithelial cells: comparison of two isolation techniques. J Craniomaxillofac Surg 2001; 29:224-31. [PMID: 11562092 DOI: 10.1054/jcms.2001.0229] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Cultured epithelial cells offer many potential clinical applications. There have generally been two techniques that have been used to cultivate oral keratinocytes, which include the direct explant technique and the enzymatic method. Little work has been done comparing these two techniques and their capacity to isolate and cultivate oral keratinocytes. OBJECTIVES The objectives of this study were to (1) investigate the difference in the percentage of keratinocyte isolation between the direct explant technique and the enzymatic method of human gingival epithelial cell culture and (2) to examine the effect of age and sex of the subjects providing the tissue samples on (a) the success in cultivation and (b) the growth patterns of gingival keratinocytes. MATERIAL AND METHODS Gingival tissue was obtained from healthy human subjects and was used for keratinocyte isolation using the direct explant technique or the enzymatic method. Epithelial cell cultures from each of the two culture techniques were selected randomly for flow cytometry analysis for cell expression of vimentin and cytokeratin. Growth rate assays were also conducted. RESULTS The success rate for cultivation from the direct explant technique was higher (82%) than in the enzymatic method (57.9%). The success rate of both methods was not significantly associated with either age or sex of the subjects providing the tissue. From flow cytometry, the average percentage of cells that was positive to anti-pan cytokeratin was nearly the same for both methods at about 97%. It was noted that the cells from the enzymatic method gave significantly higher percentages of cells that were positive to anti-pan cytokeratin only. CONCLUSION Both the direct explant technique and the enzymatic method can be used for isolating and culturing human oral keratinocytes. The direct explant technique appeared to be more successful in culturing human oral keratinocytes than the enzymatic method, although there were limitations found with both methods. The age and sex of the subjects providing the gingival samples did not appear to be a factor influencing the success rate in culturing the keratinocytes. However, contamination by oral microbiological flora from the gingival tissue samples remained an ever present problem. Further studies are needed in the investigation of clinical applications of these two epithelial cell isolation methods.
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Affiliation(s)
- U Kedjarune
- Department of Oral Biology and Occlusion Faculty of Dentistry, Prince of Songkla University, Hat Yai, Thailand.
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Larcher F, Del Rio M, Serrano F, Segovia JC, Ramírez A, Meana A, Page A, Abad JL, González MA, Bueren J, Bernad A, Jorcano JL. A cutaneous gene therapy approach to human leptin deficiencies: correction of the murine ob/ob phenotype using leptin-targeted keratinocyte grafts. FASEB J 2001; 15:1529-38. [PMID: 11427484 DOI: 10.1096/fj.01-0082com] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Leptin deficiency produces a phenotype of obesity, diabetes, and infertility in the ob/ob mouse. In humans, leptin deficiency occurs in some cases of congenital obesity and in lipodystrophic disorders characterized by reduced adipose tissue and insulin resistance. Cutaneous gene therapy is considered an attractive potential method to correct circulating protein deficiencies, since gene-transferred human keratinocytes can produce and secrete gene products with systemic action. However, no studies showing correction of a systemic defect have been reported. We report the successful correction of leptin deficiency using cutaneous gene therapy in the ob/ob mouse model. As a feasibility approach, skin explants from transgenic mice overexpressing leptin were grafted on immunodeficient ob/ob mice. One month later, recipient mice reached body weight values of lean animals. Other biochemical and clinical parameters were also normalized. In a second human gene therapy approach, a retroviral vector encoding both leptin and EGFP cDNAs was used to transduce HK and, epithelial grafts enriched in high leptin-producing HK were transplanted to immunosuppressed ob/ob mice. HK-derived leptin induced body weight reduction after a drop in blood glucose and food intake. Leptin replacement through genetically engineered HK grafts provides a valuable therapeutic alternative for permanent treatment of human leptin deficiency conditions.
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Affiliation(s)
- F Larcher
- Project of Cell and Molecular Biology and Gene Therapy. CIEMAT. Avenida Complutense 22, 28040 Madrid, Spain.
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Dellambra E, Pellegrini G, Guerra L, Ferrari G, Zambruno G, Mavilio F, De Luca M. Toward epidermal stem cell-mediated ex vivo gene therapy of junctional epidermolysis bullosa. Hum Gene Ther 2000; 11:2283-7. [PMID: 11084687 DOI: 10.1089/104303400750035825] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Junctional epidermolysis bullosa (JEB) is a group of severe, inherited skin diseases caused by mutations in the genes encoding laminin 5 or other components of the hemidesmosome. Since human epidermis is a self-renewing tissue, gene therapy of JEB requires the stable integration of the transgene into the genome of the epidermal stem cell. Human epidermal stem cells can indeed be cultivated and stably transduced with replication-defective retroviral vectors, allowing full phenotypic correction of the adhesion properties of JEB keratinocytes. Epidermal stem cells generate cohesive sheets of stratified epithelium suitable for the permanent coverage of massive skin defects, and genetically modified epidermal sheets maintain long-term expression of the transgene after transplantation on immunodeficient animals. Moreover, we have developed a clinical procedure that allows transplantation of cultured epidermal sheets on large body areas under local anesthesia and without cicatricial outcomes. Thus, (1) the possibility of cultivating lining epithelia, (2) the availability of noninvasive surgical procedures that allow the grafting of large skin areas, and (3) the demonstration of sustained transgene expression in vitro and in vivo by epidermal stem cells, prompt us to propose the implementation of a phase I/II clinical trial aimed at the ex vivo gene therapy of selected JEB patients. The aim of the trial is to validate the ex vivo procedure in a clinical setting, to prove its overall safety, and to analyze critical issues such as long-term survival of the genetically modified implant, immune response against the transgene product, and persistence of transgene expression at therapeutic levels.
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Affiliation(s)
- E Dellambra
- Laboratory of Tissue Engineering, Istituto Dermopatico dell'Immacolata, 00040 Pomezia (Rome), Italy
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Sat E, Leung KH, Bruckner-Tuderman L, Cheah KS. Tissue-specific expression and long-term deposition of human collagen VII in the skin of transgenic mice: implications for gene therapy. Gene Ther 2000; 7:1631-9. [PMID: 11083471 DOI: 10.1038/sj.gt.3301281] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We report the isolation of a cosmid clone containing the entire human COL7A1 gene in one piece. The ability of the genomic sequences within this clone to direct tissue-specific expression of human collagen VII in transgenic mice was tested. The data show that the gene construct is capable of directing expression of collagen VII in the skin of fetal and neonatal transgenic mice. Expression of COL7A1 in these mice was widespread, in a pattern consistent with that found in human tissues and was in parallel with that of the endogenous mouse gene. Immunostaining, using human-specific antibodies, showed that human collagen VII protein was present at the skin basement membrane zone of the transgenic mice. Dermal extracts from 19-month-old transgenic mice contained mature human collagen VII protein, and fibroblasts derived from skin biopsies of these mice actively synthesized human collagen VII. The demonstration of successful and stable expression of human collagen VII in in vivo gene transfer is the first step towards the future development of therapeutic protocols for the rescue of keratinocyte function in severe blistering diseases such as dystrophic epidermolysis bullosa.
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Affiliation(s)
- E Sat
- Department of Biochemistry, The University of Hong Kong, China
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Pellegrini G, Ranno R, Stracuzzi G, Bondanza S, Guerra L, Zambruno G, Micali G, De Luca M. The control of epidermal stem cells (holoclones) in the treatment of massive full-thickness burns with autologous keratinocytes cultured on fibrin. Transplantation 1999; 68:868-79. [PMID: 10515389 DOI: 10.1097/00007890-199909270-00021] [Citation(s) in RCA: 294] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Cell therapy is an emerging therapeutic strategy aimed at replacing or repairing severely damaged tissues with cultured cells. Epidermal regeneration obtained with autologous cultured keratinocytes (cultured autografts) can be life-saving for patients suffering from massive full-thickness burns. However, the widespread use of cultured autografts has been hampered by poor clinical results that have been consistently reported by different burn units, even when cells were applied on properly prepared wound beds. This might arise from the depletion of epidermal stem cells (holoclones) in culture. Depletion of holoclones can occur because of (i) incorrect culture conditions, (ii) environmental damage of the exposed basal layer of cultured grafts, or (iii) use of new substrates or culture technologies not pretested for holoclone preservation. The aim of this study was to show that, if new keratinocyte culture technologies and/or "delivery systems" are proposed, a careful evaluation of epidermal stem cell preservation is essential for the clinical performance of this life-saving technology. METHODS Fibrin was chosen as a potential substrate for keratinocyte cultivation. Stem cells were monitored by clonal analysis using the culture system originally described by Rheinwald and Green as a reference. Massive full-thickness burns were treated with the composite allodermis/cultured autograft technique. RESULTS We show that: (i) the relative percentage of holoclones, meroclones, and paraclones is maintained when keratinocytes are cultivated on fibrin, proving that fibrin does not induce clonal conversion and consequent loss of epidermal stem cells; (ii) the clonogenic ability, growth rate, and long-term proliferative potential are not affected by the new culture system; (iii) when fibrin-cultured autografts bearing stem cells are applied on massive full-thickness burns, the "take" of keratinocytes is high, reproducible, and permanent; and (iv) fibrin allows a significant reduction of the cost of cultured autografts and eliminates problems related to their handling and transportation. CONCLUSION Our data demonstrate that: (i) cultured autografts bearing stem cells can indeed rapidly and permanently cover a large body surface; and (ii) fibrin is a suitable substrate for keratinocyte cultivation and transplantation. These data lend strength to the concept that the success of cell therapy at a clinical level requires cultivation and transplantation of stem cells. We therefore suggest that the proposal of a culture system aimed at the replacement of any severely damaged self-renewing tissue should be preceded by a careful evaluation of its stem cell population.
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Affiliation(s)
- G Pellegrini
- Laboratory of Tissue Engineering, I.D.I., Istituto Dermopatico dell'Immacolata, Rome, Italy
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Pellegrini G, Golisano O, Paterna P, Lambiase A, Bonini S, Rama P, De Luca M. Location and clonal analysis of stem cells and their differentiated progeny in the human ocular surface. J Cell Biol 1999; 145:769-82. [PMID: 10330405 PMCID: PMC2133195 DOI: 10.1083/jcb.145.4.769] [Citation(s) in RCA: 488] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/1998] [Revised: 03/19/1999] [Indexed: 12/21/2022] Open
Abstract
We have analyzed the proliferative and differentiation potential of human ocular keratinocytes. Holoclones, meroclones, and paraclones, previously identified in skin, constitute also the proliferative compartment of the ocular epithelium. Ocular holoclones have the expected properties of stem cells, while transient amplifying cells have variable proliferative potential. Corneal stem cells are segregated in the limbus, while conjunctival stem cells are uniformly distributed in bulbar and forniceal conjunctiva. Conjunctival keratinocytes and goblet cells derive from a common bipotent progenitor. Goblet cells were found in cultures of transient amplifying cells, suggesting that commitment for goblet cell differentiation can occur late in the life of a single conjunctival clone. We found that conjunctival keratinocytes with high proliferative capacity give rise to goblet cells at least twice in their life and, more importantly, at rather precise times of their life history, namely at 45-50 cell doublings and at approximately 15 cell doublings before senescence. Thus, the decision of conjunctival keratinocytes to differentiate into goblet cells appears to be dependent upon an intrinsic "cell doubling clock. " These data open new perspectives in the surgical treatment of severe defects of the anterior ocular surface with autologous cultured conjunctival epithelium.
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Affiliation(s)
- G Pellegrini
- Laboratory of Tissue Engineering, I.D.I.-IRCCS, Istituto Dermopatico dell'Immacolata, Rome, Italy
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