Published in eBiology: A LifeSciences Journal on Wed Sep 25 2019 05:40:23 GMT-0400 (Eastern Daylight Time)
Vol: 1, No: 4, Page: 10-19
Dr. Mina Mashhadi , Department of Biology
Department of Neontology, Mashhad University of Medical Sciences, Iran
Stem cells (SCs) are a population of undifferentiated cells with high self-renewing and differentiation potency. On the basis of origin, SCs are divided into four main groups: embryonic stem cells (ESCs), fetal stem cells (FSCs), induced pluripotent stem cells (iPSCs), and adult stem cells (ASCs). Interestingly, in different literatures, ASCs are considered as unipotent progenitor cells, multipotent stem cells or even pluripotent stem cells with variety of differentiation potential. ASCs reside in many adult tissues such as liver, bone marrow, adipose tissue, neural tissues, skin and etc. Among adult tissues, skin is considered as a fast self-renewing tissue which is capable to reconstruct itself during skin homeostasis and injuries. In fact, skin is mentioned as a pool of different types of SCs including keratinocyte stem cells (KSCs), hair follicle stem cells (HFSCs) and sebaceous gland stem cells (SGSCs). During skin regeneration, cooperation between these stem cells is essential for reconstruction of skin. Among these SCs, KSCs are most common cells in epidermis layer (mostly in basal layer) which are the important population of SCs for regeneration of epidermis. Herein, we reviewed different methods for skin stem cells isolation and characterization, and their potential for clinical application.
Stem cells (SCs) are a population of unspecialized cells with self-renewal ability and differentiation potential [ 1, 2]. SCs are able to proliferate and differentiate into many cell lineages of tissue of origin that they are derived from . Therefore, applying of SCs has been considering for addressing issues like tissue regeneration, drug screening and organogenesis . Typically, SCs are divided into four main groups based on their tissue of origin: embryonic stem cells (ESCs), fetal stem cells (FSCs), induced pluripotent stem cells (iPSCs), and adult stem cells (ASCs) [2–4]. ESCs are totipotent cells which are derived from the inner cell mass (ICM) of blastocyst and capable to make an entire organism and various cells of three main germ layers (mesoderm, endoderm and ectoderm) . In contrast, ASCs have been considered as unipotent, multipotent and even pluripotent cells which are limited in their differentiation potential rather than ESCs, FSCs, and iPSCs [2, 3, 6–8]. In spite of high differentiation potential of ESCs, their applications have been limited due to ethical concerns, tumorigenic potential and difficulties in controlling of their rate of differentiation [2, 9]. Therefore, using of ASCs, as a most promising source for clinical practice and trials, has been developed because represent evidence of safety [9–11]. Generally, ASCs are multipotent cells which are derived from many adult tissues such as liver, bone marrow, adipose, neural tissue, and skin which are essential for regeneration of tissues/organs during various damages [12, 13]. Epidermal SCs, endothelial stem cells (EPCs), hematopoietic stem cells (HSCs), bone marrow stem cells (BMSCs) and neural stem cells (NSCs) are most common ASCs have been employed for therapeutic applications in tissue regeneration [9, 14]. Among different types of ASCs, epidermal or skin SCs are most common cells which are employed for skin repair [15, 16]. As a result, development of scientific knowledge about nature, biological function and importance of epidermal SCs in skin regeneration are required for development of call-based approaches in skin tissue engineering.
100 mM trehalose cause an accumulation of starch in source and depletion in sink tissues
Supply of the 100 mM trehalose to the Arabidopsis seedlings (WT) led to the growth arrest and development arrest in leaves. In WT seedlings, the root length was very short (1.9± 0.6 mm after 14 days) and emergence of primary leaves was entirely inhibited. The trehalase expressing seedlings (TreF, line 46.2) had 12 times longer roots than WT ones after 14 days growth on 100 mM trehalose. TreF seedling root lengths on trehalose were as long as them on the sorbitol osmoticum control (figure 1).
Figure 1. The effect of 100 mM trehalose on the root growth of WT seedlings. WT seeds were germinated and grown under long day conditions on ½ MS medium with 100 mM trehalose or sorbitol. Root length was measured after 14 days. Each experiment was repeated three times. Error bars indicate Standard deviation. The abbreviations are WT (Wild type), tre (trehalose), and sorb (sorbiyol).
Trehalose in the medium led to an accumulation of large amounts of starch in the seedling source tissue, cotyledon, and to a depletion of starch in the colummella cells of the root cap, a sink tissue (figure 2a-c). Confocal microscopy of the seedling roots stained with propidium iodine revealed swelling as well as lysis of the cells in the extension zone of roots grown on 100 mM trehalose but not on 100 mM sorbitol (figure 2d-f). In addition to altered starch distribution and reduced root growth, trehalose appeared to alter cell wall elasticity compared with sorbitol.
Distribution of starch in TreF and WT was studied in 14 d seedlings using Lugol staining. Staining revealed that the reaction to trehalose was not fully homogenous when examining a large number of WT seedlings: 72% of the seedlings responded with massive trehalose accumulation in the cotyledons whilst 28% failed to stain. The response to trehalose of seedlings expressing E.coli trehalase (TreF line) was homogenous, as cotyledons of these seedlings did not stain with Lugol. Seedlings of the TreF line displayed starch in the columnella cells of the root tips (not shown).
Quantification of starch in the WT and TreF seedlings on trehalose is shown in figure 2 g. WT seedlings contained 11 mg.g-1 FW (fresh weight) starch on medium with 100 mM sorbitol. On trehalose, the starch level in WT was increased to 52 mg.g-1 FW. TreF seedlings on trehalose contained the same amount of starch as WT on
Generally, adult tissues for example liver, intestine and blood undergo rapid self-renewal during life time of animals. In common with these tissues, the human skin is a self-renewing tissue which reconstructs itself during skin injuries. As a matter of fact, the skin is considered as a stem cell pool which variety of SC niches is embedded in it. Among different types of SCs within skin, KSCs play crucial role in epidermis permanent regeneration. As a result, development of isolation, characterization and cultivation methods of KSCs can accelerate clinical applications of KSCs for treatment of skin disorders and injuries. In spite of key role of KSCs in skin repair, application of these cells face with some difficulties and limitations, such as long culturing time, high cost, the probably of highly significant scaring in deep burn injuries which are treated by cultured keratinocytes. With these limitations in mind, application of some strategies such as: recruitment of KSCs along with epidermis layer in order to prevention of high significant scaring, combination of KSCs with scaffolds or skin substitutes as a cell delivery system and integration of melanocytes, endothelial cells even different types of ASCs like mesenchymal SCs and adipose derived-SCs into keratinocyte culture are most promising approaches for development of cell-based therapeutic methods in an improved treatment of burns, chronic wounds and hereditary skin disorders.
1 - Totey, S., Totey, S., Pal, R., & Pal, R. (2009). Adult stem cells: a clinical update. J. Stem Cells, 4(2), 105–21.
2 - Sharma, R., Bhargava, D., Rastogi, P., Yadav, M., Chandavarkar, V., Siddhartha, M., … Chandavarkar, V. (2014). Stem Cells : An Update. J. Indian Acad. Forensic Med., 36(3), 276–280.
3 - Bhartiya, D., Boheler, K. R., & Rameshwar, P. (2013). Multipotent to pluripotent properties of adult stem cells. Stem Cells Int., 2013, 2–4. doi:10.1155/2013/813780
4 - Rezanejad, H., & Matin, M. M. (2012). Induced pluripotent stem cells: progress and future perspectives in the stem cell world. Cell. Reprogram., 14(6), 459–470. doi:10.1089/cell.2012.0039
5 - Rubio, D., Garcia-Castro, J., Martín, M. C., de la Fuente, R., Cigudosa, J. C., Lloyd, A. C., & Bernad, A. (2005). Spontaneous human adult stem cell transformation. Cancer Res., 65(8), 3035–9. doi:10.1158/0008-5472.CAN-04-4194
6 - Catacchio, I., Berardi, S., & Reale, A. (2013). Evidence for bone marrow adult stem cell plasticity: properties, molecular mechanisms, negative aspects, and clinical applications of hematopoietic and mesenchymal. … Cells Int., 2013, 1–11. doi:10.1155/2013/589139
7 - Sharma, R. R., Pollock, K., Hubel, A., & McKenna, D. (2014). Mesenchymal stem or stromal cells: A review of clinical applications and manufacturing practices. Transfusion, 54(5), 1418–1437. doi:10.1111/trf.12421
8 - Mohd Hilmi, A. B., & Halim, A. S. (2015). Vital roles of stem cells and biomaterials in skin tissue engineering. World J Stem Cells, 7(2), 428–436.
9 - Brignier, A. C., & Gewirtz, A. M. (2010). Embryonic and adult stem cell therapy. J. Allergy Clin. Immunol., 125(2 Suppl 2), S336–44. doi:10.1016/j.jaci.2009.09.032
10 - Herberts, C. a, Kwa, M. S. G., & Hermsen, H. P. H. (2011). Risk factors in the development of stem cell therapy. J. Transl. Med., 9(1), 29. doi:10.1186/1479-5876-9-29
11 - Lamas, N. J., Serra, S. C., Salgado, A. J., & Sousa, N. (2015). Failure of Y-27632 to improve the culture of adult human adipose-derived stem cells. Stem Cells Cloning, 8, 15–26. doi:10.2147/SCCAA.S66597
12 - Blanpain, C., Lowry, W. E., Geoghegan, A., Polak, L., & Fuchs, E. (2004). Self-renewal, multipotency, and the existence of two cell populations within an epithelial stem cell niche. Cell, 118(5), 635–648. doi:10.1016/j.cell.2004.08.012
13 - Mudda, J. A., & Bajaj, M. (2011). Stem cell therapy: a challenge to periodontist. Indian J. Dent. Res., 22(1), 132–9. doi:10.4103/0970-9290.79978
14 - Robey, P. G., Kuznetsov, S. A., Ren, J., Klein, H. G., Sabatino, M., & Stroncek, D. F. (2015). Generation of clinical grade human bone marrow stromal cells for use in bone regeneration. Bone, 70, 87–92. doi:10.1016/j.bone.2014.07.020
15 - Huang, L., & Burd, A. (2012). An update review of stem cell applications in burns and wound care. Indian J. Plast. Surg., 45(2), 229–36. doi:10.4103/0970-0358.101285
16 - Chunmeng, S., & Tianmin, C. (2004). Skin: a promising reservoir for adult stem cell populations. Med. Hypotheses, 62(5), 683–688. doi:10.1016/j.mehy.2003.12.022
17 - Tan, K. K. B., Salgado, G., Connolly, J. E., Chan, J. K. Y., & Lane, E. B. (2014). Characterization of fetal keratinocytes, showing enhanced stem cell-like properties: A potential source of cells for skin reconstruction. Stem Cell Reports, 3(2), 324–338. doi:10.1016/j.stemcr.2014.06.005
18 - Ambler, C. A., & Määttä, A. (2009). Epidermal stem cells: Location, potential and contribution to cancer. J. Pathol., 217(2), 206–216. doi:10.1002/path.2468
19 - Schlüter, H., Paquet-Fifield, S., Gangatirkar, P., Li, J., & Kaur, P. (2011). Functional characterization of quiescent keratinocyte stem cells and their progeny reveals a hierarchical organization in human skin epidermis. Stem Cells, 29(8), 1256–1268. doi:10.1002/stem.675
20 - Martinez-Agosto, J. (2007). The hematopoietic stem cell and its niche: a comparative view. Genes …, 21(23), 3044–3060. doi:10.1101/gad.1602607.maintained
21 - Oh, M., & Nör, J. E. (2015). The Perivascular Niche and Self-Renewal of Stem Cells. Front. Physiol., 6(DEC), 1–6. doi:10.3389/fphys.2015.00367
22 - Schepeler, T., Page, M. E., & Jensen, K. B. (2014). Heterogeneity and plasticity of epidermal stem cells. Development, 141(13), 2559–2567. doi:10.1242/dev.104588
23 - Blanpain, C., & Fuchs, E. (2006). Epidermal stem cells of the skin. Annu. Rev. Cell Dev. Biol., 22, 339–73. doi:10.1146/annurev.cellbio.22.010305.104357
24 - Eckert, R. L., Adhikary, G., Balasubramaniam, S., Rorke, E. A., Vemuri, M. C., Boucher, S. E., … Kerra, C. (2013). Biochemistry of epidermal stem cells. Biochim. Biophys. Acta, 1830(2), 2427–2434.
25 - Hsu, Y.-C., Li, L., & Fuchs, E. (2014). Emerging interactions between skin stem cells and their niches. Nat. Med., 20(8), 847–56. doi:10.1038/nm.3643
26 - Jensen, U. B., Ghazizadeh, S., & Owens, D. M. (2013). Isolation and characterization of cutaneous epithelial stem cells. In K. Turksen (Ed.), Methods Mol. Biol. (Vol. 989, pp. 61–69). Totowa, NJ: Humana Press. doi:10.1007/978-1-62703-330-5_6
27 - Farivar, S., & RojhanNejad, M. (2015). Hair Follicle Stem Cell: Molecular Basis of Development, and Regeneration. J. Genes Cells, 1(3), 57–66. doi:10.15562/gnc.20
28 - Lai-Cheong, J. E., & McGrath, J. A. (2013). Structure and function of skin, hair and nails. Med. (United Kingdom), 41(6), 317–320. doi:10.1016/j.mpmed.2013.04.017
29 - You, H.-J., Han, S.-K., Lee, J.-W., & Chang, H. (2010). Treatment of diabetic foot ulcers using cultured allogeneic keratinocytes--a pilot study. Wound Repair Regen., 20, 491–9. doi:10.1111/j.1524-475X.2012.00809.x