The fetal period
Frank J. Dye in Human Life Before Birth, 2019
During much of the twentieth century, researchers extensively used cell culture in biomedical research. Additionally, tissue, organ, and embryo culture were also used. The formation of an organ during development is called organogenesis. A certain amount of organogenesis could occur in culture; for example, the development of mouse tooth germs (embryonic mouse teeth) would undergo a certain amount of organogenesis in vitro (i.e., in culture); however, organ culture was limited by size restrictions related to the rate of diffusion of nutrients into the volume of the organ or organ fragments. Embryo cultures, especially of mouse embryos, were limited to early development because mammalian embryos must at some point implant into a uterus, so although these embryo cultures provided good insight into early mammalian development, development beyond the blastocyst stage would be hidden from view. Cell and tissue cultures for most of the twentieth century were generally two-dimensional (2D) cultures (see Figure 9.9), as the cells or tissues grew as a flat layer on their glass, or, increasingly, plastic, substratum. A relatively recent innovation involves the use of 3D cultures (see Figure 9.10). This is a more natural environment for the cultures, as cells grow in vivo (i.e., within the organism) in three dimensions.
Next Generation Tissue Engineering Strategies by Combination of Organoid Formation and 3D Bioprinting
Naznin Sultana, Sanchita Bandyopadhyay-Ghosh, Chin Fhong Soon in Tissue Engineering Strategies for Organ Regeneration, 2020
Organogenesis, during embryonic stage, is governed by a constellation of complex processes, involving cell-cell and cell-matrix protein interactions, cell migration, regulation of large number of signaling molecules and signaling pathways. Progenitor cells differentiate to specific phenotypes, and produce organ specific ECM. At the same time, according to the embryonic developmental plan and anatomical architecture, concerted cellular self-assembly leads to formation of the “organ germ”. These rudimentary organ germs then undergo organ-specific morphogenesis to meet the requirements of biological as well as mechanical functionality (Sasai 2013, Sasai et al. 2012). Since past few decades, tissue engineers have tried to recapitulate these complex developmental biology signaling cascades and morphogenesis by combining progenitor cells or primary cells, various polymeric scaffolds, and bioactive molecules or growth factors by using tissue engineering techniques in vitro. But in the past decades, very few tissue engineered constructs could achieve desired level of success in human clinical trials.
Comparison of Healing Effect of DMSP in Green Sea Algae and Mesenchymal Stem Cells on Various Inflammatory Disorders
Se-Kwon Kim in Marine Biochemistry, 2023
Embryonic mesenchymal stem cells (EB-MSCs) prepared from mouse embryo are pluripotent stem cells (Evans & Kaufman, 1981) which can develop to ectodermal- (i.e. skin epithelial and dermis cells, central and peripheral nerve cells, etc.), endodermal (digestive tract, lung, pancreas, liver, etc.), mesodermal (heart and kidney cells, skeletal muscle cells, etc.) lineage cells, and neural crest (glial cells, peripheral neuronal cells) eventually give rise to all of animal’s tissues and organs through the process of organogenesis. However, the transplantation of EB-MSCs into the mouse possibly causes the occurrence of teratoma and tumor (Evans & Kaufman, 1981; Knoepfler, 2009; Stacheischeid et al., 2013). Moreover, as for the artificial preparation and clinical employment of the primordia of life, EB-MSCs have a significant ethical problem for animals, in particular humans, and the healing effect of DMSP and EB-MSCs was not compared here.
Bioengineering strategies for nephrologists: kidney was not built in a day
Published in Expert Opinion on Biological Therapy, 2020
Anna Julie Peired, Benedetta Mazzinghi, Letizia De Chiara, Francesco Guzzi, Laura Lasagni, Paola Romagnani, Elena Lazzeri
Xenotransplantation of embryonic kidney offers a series of advantages over adult kidney. The kidney primordium is genetically preprogrammed to develop a functional kidney. It requires multiple organogenesis steps to be functional in embryogenesis through adulthood. Indeed, metanephroi from pig embryos transplanted into the omentum of unilaterally nephrectomized adult pigs or mice that received costimulatoring blocking agents (anti-CD45RB, anti-CD154, and anti-CD11a) developed into an enlarged, vascularized structure formed of mature tubules and glomeruli [29]. Another advantage is the fact that the primordia attracts the host vasculature and is therefore less susceptible to humoral rejection [30]. Human metanephroi transplanted into immunodeficient mice exhibited rapid growth and development. Embryonic kidney was shown to be less immunogenic than adult organ when transplanted in fully immunocompetent hosts [31]. Further analysis indicated no risk of malignant transformation. Altogether, embryonic tissues represent a valid alternative to adult tissue as a source of organ for xenotransplantation.
Regenerating the kidney using human pluripotent stem cells and renal progenitors
Published in Expert Opinion on Biological Therapy, 2018
Francesca Becherucci, Benedetta Mazzinghi, Marco Allinovi, Maria Lucia Angelotti, Paola Romagnani
The generation of transplantable kidneys is among the ultimate goals of regenerative nephrology due to a shortage of donor organs that represents a critical obstacle to the expansion of transplantation programs. Notwithstanding this, the complex 3D cellular and tissue interactions required for organogenesis are quite difficult to recapitulate in vitro. Blastocyst complementation is a method used to overcome these obstacles. Briefly, it consists in generating organs in vivo by injecting pluripotent SCs (either ESCs or iPSCs) into blastocyst-stage embryos (mainly, but not exclusively, rodents). This finally leads to the generation of chimeric embryos in which pluripotent SCs contribute to the generation of host tissues and organs [79]. Interspecies blastocyst complementation is a variation of the classical technique in which the recipient host is genetically manipulated to carry DNA mutations that prevent the development of a target organ [80]. Ideally, the injection of donor-derived pluripotent SCs would developmentally compensate for the defect and form the missing organ. This strategy had been initially used for the reconstitution of bone marrow but was subsequently applied to the generation of entire organs (e.g. pancreas, heart, eye) [81]. The resulting organs are composed almost entirely of cells derived from donor, even if the blastocyst complementation involves different species.
Advances in understanding vertebrate nephrogenesis
Published in Tissue Barriers, 2020
Joseph M. Chambers, Rebecca A. Wingert
Vertebrate development entails the formation of three germ layers, the ectoderm, mesoderm, and endoderm, which provide cellular blueprints for embryonic organogenesis. Ectoderm gives rise to the central nervous system and skin cells, and endoderm derivatives encompass cells that line the respiratory and digestive tracts. The mesoderm, or middle layer, produces cells that are most abundant in the human body constituting skeletal muscle, cartilage, heart, gonads, and blood, among other tissue types.1 This review will focus on a member of the mesoderm lineage: the kidney. Much of our understanding about kidney development stems from rodent models, but also has benefited from studies in other vertebrates such as fish, frogs, and birds.2The inception of mesoderm development begins with the differentiation of pluripotent epiblast cells into a transient ‘primitive streak’ zone.1Position along the anterior-posterior embryonic axis and other instructive signals regulate the regionalization of paraxial, intermediate, and lateral plate mesoderm.3
Related Knowledge Centers
- Birth
- Ectoderm
- Endoderm
- Gastrulation
- Germ Layer
- Mesoderm
- Paracrine Signaling
- Embryo
- Cellular Differentiation
- Juxtacrine Signalling