Commitment of stem cells to nerve cells and migration of nerve cell precursors in preparatory bud development in Hydra

Development ◽  
1980 ◽  
Vol 60 (1) ◽  
pp. 373-387
Author(s):  
Stefan Berking

Budding in Hydra starts as an evagination of the double-layered tissue in the parent animal's gastric region. Five hours later the density of nerve cells in the bud's tissue doubles, representing the first detectable difference from the cellular composition of the surrounding tissue. These new nerve cells derive from multipotent stem cells which are in S-phase one day before evagination starts. Some of the bud's new nerve cells derive from stem cells which have migrated into the future bud's tissue after their commitment, apparently attracted by the bud anlage. The bud anlage recruits precursors of nerve cells even during starvation, during which nerve cell production ceases in other parts of the body. Furthermore, the bud anlage controls the duration of the development from commitment to final differentiation of the resulting nerve cells. Experiments with an inhibitor purified from hydra tissue indicate a tight correlation between stages of preparatory bud development and stages of recruitment of nerve cells for the bud. Whether or not precursors of nerve cells are involved in the control of bud formation in normal hydra, as compared to epithelial hydra which still bud though consisting of epithelial cells only, will be discussed.

1979 ◽  
Vol 40 (1) ◽  
pp. 193-205 ◽  
Author(s):  
S. Berking

Feeding of starved animals provides a very short signal which determines stem cells to differentiate into nerve cells after the next mitosis. Only those stem cells become determined which are just in the middle of their S-phase at the time of feeding. Stem cells of any other stage of the cycle do not become determined. Nerve cell determination is suppressed by very low concentrations of an endogenous inhibitor. The inhibitor exerts its effect only during the first half of the S-phase, not before and not after this period. Based on these finding it is proposed that stem cells are susceptible to 2 different signals during the first half of their S-phase; one signal allows the development into nerve cells, the other prevents this development. Within this period the decision whether to become a nerve cell or not is reversible. It becomes fixed at the end of this period.


Author(s):  
Lin Yuan ◽  
Naoya Sakamoto ◽  
Guanbin Song ◽  
Masaaki Sato

Mesenchymal stem cells (MSCs) represent as multipotent stem cells which hold the abilities of self-renewal and give rise to cells of diverse lineages [1]. With their remarkable combination of multipotent differentiation potential and low immunogenicity, MSCs are considered to be an attractive candidate for cell-based tissue repair and regenerative tissue engineering [2, 3]. Increasing number of studies has demonstrated that mobilization and migration of injected MSCs to the damaged tissues is a key step for these cells to participate in disease treatment and tissue regeneration [4, 5].


1981 ◽  
Vol 52 (1) ◽  
pp. 85-98
Author(s):  
S. Heimfeld ◽  
H.R. Bode

The interstitial cell of hydra is a multipotent stem cell, which produces nerve cells as one of its differentiated cell types. The amount of interstitial cell commitment to nerve differentiation varies in an axially dependent pattern along the body column. The distribution of nerve cell density has the same equivalent axial pattern. These facts have led to speculation that the regulation of nerve cell commitment is dictated by the nerve cell density. We examined this question by assaying interstitial cell commitment behaviour in 2 cases where the normal nerve cell density of the tissue had been perturbed: (1) in epithelial hydra in which no nerve cells were present; and (2) in hydra derived from regenerating-tip isolates in which the nerve density was increased nearly 4-fold. We found no evidence of regulation of nerve cell commitment in response to the abnormal nerve cell densities. However, the typical axial pattern of nerve commitment was still obtained in both sets of experiments, which suggests that interstitial cell commitment to nerve differentiation is dependent on some parameter of axial location that is not associated directly with the local nerve cell density.


Author(s):  
Rajaventhan Srirajaskanthan ◽  
Martyn E. Caplin ◽  
Humphrey Hodgson

Neuroendocrine tumours (NETs) are derived from cells of the diffuse neuroendocrine system, which are present in organs throughout the body. Originally, Pearse proposed that tumours develop from migration of cells from the neural crest; however, it is now thought that the tumour cells are derived from multipotent stem cells (1). The term ‘karzinoide’ (meaning carcinoma like) was initially introduced by Siegfried Oberndorfer in 1907 (2). The term carcinoid tumour has historically been used; however, with advances in the understanding of the tumour biology, and the recent WHO classification, the term NET or endocrine tumour is considered more appropriate, and more details are given in the historical introduction in Chapter 6.1.


1978 ◽  
Vol 34 (1) ◽  
pp. 1-26
Author(s):  
M.S. Yaross ◽  
H.R. Bode

The interstitial cell (i-cell) of hydra, a multipotent stem cell, produces two classes of differentiated cell types, nerve cells and nematocytes, throughout asexual growth. Using a new assay, the regulation of i-cell commitment to either nerve cell or nematocyte differentiation was investigated. This assay was used to determine the fractions of i-cells differentiating into nerve cells and nematocyte precursors in a variety of in vivo cellular milieus produced by hydroxyurea treatment, differential feeding, and reaggregation of dissociated cells. Nematocyte commitment was found to be positively correlated with the size of the i-cell population and independent of the axial position of the i-cells along the body column. This indicates that i-cell commitment to nematocyte differentiation may be regulated by feedback from the i-cell population. Nerve cell commitment was found to be correlated with regions of high nerve cell density. This suggests that nerve cell commitment is regulated by feedback from the nerve cell population or is dependent on axial position. Implications of such mechanisms for the regulation of i-cell population size and distribution are discussed.


2020 ◽  
Vol 15 (5) ◽  
pp. 449-461 ◽  
Author(s):  
Weidong Zhang ◽  
Genglei Chu ◽  
Huan Wang ◽  
Song Chen ◽  
Bin Li ◽  
...  

Differentiation of stem cells, a crucial step in the process of tissue development, repair and regeneration, can be regulated by a variety of mechanical factors such as the stiffness of extracellular matrix. In this review article, the effects of stiffness on the differentiation of stem cells, including bone marrow-derived stem cells, adipose-derived stem cells and neural stem cells, are briefly summarized. Compared to two-dimensional (2D) surfaces, three-dimensional (3D) hydrogel systems better resemble the native environment in the body. Hence, the studies which explore the effects of stiffness on stem cell differentiation in 3D environments are specifically introduced. Integrin is a well-known transmembrane molecule, which plays an important role in the mechanotransduction process. In this review, several integrin-associated signaling molecules, including caveolin, piezo and Yes-associated protein (YAP), are also introduced. In addition, as stiffness-mediated cell differentiation may be affected by other factors, the combined effects of matrix stiffness and viscoelasticity, surface topography, chemical composition, and external mechanical stimuli on cell differentiation are also summarized.


2020 ◽  
Author(s):  
Rui-Fang Li ◽  
Guo-Xing Nan ◽  
Dan Wang ◽  
Chang Gao ◽  
Juan Yang ◽  
...  

Abstract Background : The effects of Simian virus 40 T antigen (SV40T) on various kinds of cells are different. Previous researchers failed to use SV40T immortalized nerve cells. However, they argued that SV40T caused nerve cell transformation. No one further study what is the specific effect of SV40T on nerve cells. We transfected Schwann cells (SCs) that did not have differentiation ability with MPH 86 plasmid containing SV40T in order to explore the effects of SV40T on Schwann cells. Methods: SCs were transfected with MPH 86 plasmid carrying the SV40T gene and cultured in different media, as well as co-cultured with neural stem cells (NSCs). In our study, SCs overexpressing SV40T were defined as SV40T-SCs. The proliferation of these cells was detected by WST-1, and the expression of different biomarkers was analyzed by qPCR and immunohistochemistry. Results: SV40T induced the characteristics of NSCs, such as the ability to grow in suspension, form spheroid colonies and proliferate rapidly, in the SCs, which were reversed by knocking out SV40T by the Flip-adenovirus . In addition, SV40T up-regulated the neurocrest markers Nestin, Pax3 and Slug, and down-regulated S100b as well as the late differentiation markers MBP, GFAP and Olig1/2. These cells also expressed NSC markers like Nestin, SOX2, CD133 and SSEA-1, as well as early development markers of embryonic stem cells (ESCs) like BMP4, C-myc, OCT4 and Gbx2. Co-culturing with NSCs induced differentiation of the SV40T-SCs into neuronal and glial cells. Conclusions: SV40T reprograms Schwann cells to stem-like cells at the stage of neural crest cells that can differentiate to terminal nerve cells. Background : The effects of Simian virus 40 T antigen (SV40T) on various kinds of cells are different. Previous researchers failed to use SV40T immortalized nerve cells. However, they argued that SV40T caused nerve cell transformation. No one further study what is the specific effect of SV40T on nerve cells.


Development ◽  
1997 ◽  
Vol 124 (2) ◽  
pp. 569-576 ◽  
Author(s):  
G. Hager ◽  
C.N. David

The nervous system of the fresh water polyp hydra is built up as a nerve net spread over the whole body, with higher densities in the head and the foot. In adult hydra, as a result of continuous growth, new nerve cell differentiation takes place continuously. The pattern of nerve cell differentiation and the role of nerve cell precursor migration in establishing the pattern have been observed in vivo by vitally labelling precursor cells with DiI. The results indicate that nerve cell precursors arise directly from stem cells, complete a final cell cycle and divide, giving rise to two daughter cells, which differentiate into nerve cells. A subpopulation of the nerve cell precursors are migratory for a brief interval at the onset of the terminal cell cycle, then complete the cell cycle and divide at the site of differentiation. Labelling small patches of tissue in the head, body column and peduncle/foot with DiI indicated that formation of nerve cell precursors was nearly constant at all three positions. However, at least half of the labelled precursors in the body column migrated to the head or foot before differentiating; by contrast, precursors in head and foot differentiated in situ without significant migration. This redistribution leads to a net increase of nerve cell precursors in head and foot compared to body column and thus to the higher density of nerve cells in these regions.


2019 ◽  
Vol 20 (12) ◽  
pp. 3083 ◽  
Author(s):  
Marcin Piejko ◽  
Anna Jablonska ◽  
Piotr Walczak ◽  
Miroslaw Janowski

The physiological spaces (lateral ventricles, intrathecal space) or pathological cavities (stroke lesion, syringomyelia) may serve as an attractive gateway for minimally invasive deployment of stem cells. Embedding stem cells in injectable scaffolds is essential when transplanting into the body cavities as they secure favorable microenvironment and keep cells localized, thereby preventing sedimentation. However, the limited migration of transplanted cells from scaffold to the host tissue is still a major obstacle, which prevents this approach from wider implementation for the rapidly growing field of regenerative medicine. Hyaluronan, a naturally occurring polymer, is frequently used as a basis of injectable scaffolds. We hypothesized that supplementation of hyaluronan with activated proteolytic enzymes could be a viable approach for dissolving the connective tissue barrier on the interface between the scaffold and the host, such as pia mater or scar tissue, thus demarcating lesion cavity. In a proof-of-concept study, we have found that collagenase and trypsin immobilized in hyaluronan-based hydrogel retain 60% and 28% of their proteolytic activity compared to their non-immobilized forms, respectively. We have also shown that immobilized enzymes do not have a negative effect on the viability of stem cells (glial progenitors and mesenchymal stem cells) in vitro. In conclusion, proteolytic rafts composed of hyaluronan-based hydrogels and immobilized enzymes may be an attractive strategy to facilitate migration of stem cells from injectable scaffolds into the parenchyma of surrounding tissue.


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