Tissue Engineering and Regenerative Medicine: A New Frontier in Repairing Organ Damage - The Scientist

What Are Stem Cells?
Stem cells are unspecialized cells susceptible of self-renewal that tin differentiate into different types of cells. They cannot past extracurricular of their situation without circumstantial factors and cytokines. Stem cells beryllium some successful embryos and big tissue, and their developmental imaginable decreases arsenic they go much specialized. For example, a unipotent stem compartment cannot differentiate into arsenic galore compartment types arsenic a pluripotent stem cell.^1,2 

Mechanisms of Stemness
The developmental potential, oregon potency, of a stem compartment varies based connected its specialization. Totipotent stem cells person the highest differentiation potential. Unlike pluripotent stem cells, totipotent stem cells tin disagreement and differentiate into each compartment that makes a full organism, including some embryonic and extraembryonic structures. An illustration of a totipotent compartment is simply a zygote that develops aft a sperm fertilizes an egg. As the totipotent zygote divides into much specialized cells, it forms a blastocyst that contains pluripotent cells successful the interior compartment mass, including embryonic stem cells (ESCs).^1,3

Human pluripotent stem cells springiness emergence to each 3 superior germ layers during embryonic development. This means that they tin make into each cells of the big body, but bash not signifier extraembryonic structures specified arsenic the placenta. During embryogenesis, ESCs differentiate into 1 of 3 germ layers: ectoderm, mesoderm, oregon endoderm. These layers nutrient differentiated cells and tissues. After embryogenesis, pluripotent stem cells besides beryllium arsenic undifferentiated cells passim the organism. These cells proliferate to signifier the adjacent procreation of stem cells and differentiate into specialized cells nether circumstantial physiological conditions.^1,3 Conversely, the stem compartment situation and circumstantial stem compartment factors tin beforehand the dedifferentiation of specialized cells and instrumentality them to a primitive authorities of improvement oregon stemness.²

         

Stem cells’ developmental imaginable decreases arsenic they go much specialized. After fertilization, the totipotent zygote divides into much specialized cells and forms a blastocyst that contains pluripotent ESCs successful the interior compartment mass. ESCs differentiate into 1 of 3 germ layers that nutrient differentiated cells and tissues of the fetus and big organism.

How Do Researchers Use Pluripotent Stem Cells?
Pluripotent stem cells tin self-renew indefinitely portion maintaining the quality to differentiate into each compartment types successful vitro and successful vivo. Because of this, researchers usage pluripotent stem compartment lines to survey aboriginal development. These compartment lines are besides a root of unspecialized cells with therapeutic potential. Scientists civilization pluripotent stems cells to recognize however they whitethorn beryllium employed successful regenerative medicine, illness modeling, and cause discovery.^1,3

Embryonic Development Research
Pluripotent stem compartment features germinate arsenic improvement proceeds done embryogenesis, and antithetic stages of this process are marked by chiseled cellular transcriptional and epigenetic signatures. During development, cells mature done a continuum of pluripotent states with unsocial properties that researchers tin seizure successful vitro with unchangeable pluripotent stem compartment types. Additionally, the find of iPSCs demonstrated that scientists tin alteration compartment destiny artificially by activating lone a fewer transcription factors. This uncovering precocious researchers’ knowing of epigenetic mechanisms that perpetrate specialized cells to their differentiated states during development.^3,4 

Disease Modeling with Pluripotent Stem Cells
Scientists make a assortment of disease-relevant compartment types with quality ESCs and iPSCs utilizing differentiation protocols that mimic successful vivo organogenesis. Thus, researchers usage pluripotent stem cells to exemplary diseases with the purpose of processing therapies. For example, iPSC-derived disease-specific stem cells are utile successful the survey of degenerative disorders, and to summation penetration into diseases that deficiency suitable preclinical models. Scientists besides use pluripotent stem cells successful illness modeling with organoids, 3D structures derived from stem cells, progenitor cells, and/or differentiated cells that self-organize to recapitulate aspects of the autochthonal insubstantial operation and relation successful vitro.^4,5

Regenerative Medicine and Drug Discovery with Patient-Specific Pluripotent Stem Cells
Regenerative medicine aims to reconstruct the relation of circumstantial tissues for patients with terrible injuries oregon chronic illness conditions. Scientists usage disease-specific iPSCs to analyse imaginable degenerative upset treatments with stem compartment transplants. In addition, patient-specific pluripotent stem cells supply a promising level for cause find and compartment therapy successful vitro. For example, scientists survey patient-derived iPSCs successful vitro to analyse the effects of mutations linked to illness hazard that are identified successful genome-wide relation studies (GWAS).^4–6

References

1. W. Zakrzewski et al., “Stem cells: past, present, and future,” Stem Cell Res Ther, 10:1-22, 2019.
2. P.M. Aponte, A. Caicedo, “Stemness successful cancer: Stem cells, crab stem cells, and their microenvironment,” Stem Cells Int, 2017:1-17, 2017.
3. S. Morgani et al., “The galore faces of pluripotency: successful vitro adaptations of a continuum of successful vivo states,” BMC Dev Biol, 17:1-20, 2017.
4. M. Stadtfeld, K. Hochedlinger, “Induced pluripotency: history, mechanisms, and applications,” Genes Dev, 24:2239-63, 2010.
5. W. Hu, M.A. Lazar, “Modelling metabolic diseases and cause effect utilizing stem cells and organoids,” Nat Rev Endocrinol, s41574-022-00733-z, online up of print, 2022.
6. R.S. Mahla, “Stem cells applications successful regenerative medicine and illness therapeutics,” Int J Cell Biol, 2016:1-24, 2016.