Control of Adult Stem Cell Function in Bioengineered in vitro Niches

IntroductionAdult stem cell function has been one of the most intensively explored areas of biological and biomedical research, with hair follicle stem cells serving as one of the best model systems. This study explored the role of the transcription factor DLX5 in regulating hair follicle stem cell (HFSC) differentiation.MethodsHFSCs were isolated, characterized, and assessed for their expression of DLX5, c-MYC, NSD1, and miR-29c-3p using RT-qPCR, Western blot analysis, or immunofluorescence. Next, the ability of HFSCs to proliferate as well as differentiate into either sebaceous gland cells or epidermal cells was determined. The binding of DLX5 to the c-MYC promoter region, the binding of c-MYC to the miR-29c-3p promoter region, and the binding of miR-29c-3p to the 3′-UTR of NSD1 mRNA were verified by luciferase activity assay and ChIP experiments.ResultsDLX5 was highly expressed in differentiated HFSCs. DLX5 transcriptionally activated c-MYC expression to induce HFSC differentiation. c-MYC was able to bind the miR-29c-3p promoter and thus suppressed its expression. Without miR-29c-3p mediated suppression, NSD1 was then able to promote HFSC differentiation. These in vitro experiments suggested that DLX5 could promote HFSC differentiation via the regulation of the c-MYC/miR-29c-3p/NSD1 axis.DiscussionThis study demonstrates that DLX5 promotes HFSC differentiation by modulating the c-MYC/miR-29c-3p/NSD1 axis and identifies a new mechanism regulating HFSC differentiation.

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Size-controlled human adipose-derived stem cell spheroids hybridized with single-segmented nanofibers and their effect on viability and stem cell differentiation

Biomaterials Research ◽

10.1186/s40824-021-00215-9 ◽

2021 ◽

Vol 25 (1) ◽

Author(s):

Jinkyu Lee ◽

Sangmin Lee ◽

Sung Min Kim ◽

Heungsoo Shin

Keyword(s):

Stem Cell ◽

Cell Function ◽

Average Length ◽

Three Dimensional ◽

Stem Cell Differentiation ◽

Cell Spheroids ◽

Significant Difference ◽

Vitro Analysis ◽

Physical And Chemical

Abstract Background Fabrication of three-dimensional stem cell spheroids have been studied to improve stem cell function, but the hypoxic core and limited penetration of nutrients and signaling cues to the interior of the spheroid were challenges. The incorporation of polymers such as silica and gelatin in spheroids resulted in relatively relaxed assembly of composite spheroids, and enhancing transport of nutrient and biological gas. However, because of the low surface area between cells and since the polymers were heterogeneously distributed throughout the spheroid, these polymers cannot increase the cell to extracellular matrix interactions needed to support differentiation. Methods We developed the stem cell spheroids that incorporate poly(ι-lactic acid) single-segmented fibers synthesized by electrospinning and physical and chemical fragmentation. The proper mixing ratio was 2000 cells/μg fibers (average length of the fibers was 50 μm - 100 μm). The SFs were coated with polydopamine to increase cell binding affinity and to synthesize various-sized spheroids. The function of spheroids was investigated by in vitro analysis depending on their sizes. For statistical analysis, Graphpad Prism 5 software (San Diego, CA, USA) was used to perform one-way analysis of variance ANOVA with Tukey’s honest significant difference test and a Student’s t-test (for two variables) (P < 0.05). Results Spheroids of different sizes were created by modulating the amount of cells and fibers (0.063 mm2–0.322 mm2). The fibers in the spheroid were homogenously distributed and increased cell viability, while cell-only spheroids showed a loss of DNA contents, internal degradation, and many apoptotic signals. Furthermore, we investigated stemness and various functions of various-sized fiber-incorporated spheroids. In conclusion, the spheroid with the largest size showed the greatest release of angiogenic factors (released VEGF: 0.111 ± 0.004 pg/ng DNA), while the smallest size showed greater effects of osteogenic differentiation (mineralized calcium: 18.099 ± 0.271 ng/ng DNA). Conclusion The spheroids incorporating polydopamine coated single-segmented fibers showed enhanced viability regardless of sizes and increased their functionality by regulating the size of spheroids which may be used for various tissue reconstruction and therapeutic applications.

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AUTOLOGOUS CORNEAL REPAIR USING IN-VITRO ADULT STEM CELL EXPANSION

Journal of Stem Cell and Regenerative Biology ◽

10.15436/2471-0598.16.010 ◽

2016 ◽

Vol 2 (1) ◽

pp. 1-7

Author(s):

Charles McGhee ◽

◽

Peter J Wilson ◽

Jeremy J Mathan ◽

Jennifer J McGhee ◽

...

Keyword(s):

Stem Cell ◽

Cell Expansion ◽

Adult Stem Cell ◽

Stem Cell Expansion

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Repletion of Nicotinamide adenine dinucleotide restores adult stem cell function and extends lifespan in mice

AME Medical Journal ◽

10.21037/amj.2017.07.05 ◽

2017 ◽

Vol 2 ◽

pp. 96-96

Author(s):

Xudong Fu ◽

Min Chai ◽

Brett Lomenick

Keyword(s):

Stem Cell ◽

Nicotinamide Adenine Dinucleotide ◽

Cell Function ◽

Adult Stem Cell ◽

Nicotinamide Adenine

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Defining Adult Stem Cell Function at Its Simplest: The Ability to Replace Lost Cells through Mitosis

Cell Stem Cell ◽

10.1016/j.stem.2019.07.002 ◽

2019 ◽

Vol 25 (2) ◽

pp. 174-183 ◽

Cited By ~ 33

Author(s):

Yorick Post ◽

Hans Clevers

Keyword(s):

Stem Cell ◽

Cell Function ◽

Adult Stem Cell

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Drosophila YBX1 homolog YPS promotes ovarian germ line stem cell development by preferentially recognizing 5-methylcytosine RNAs

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1910862117 ◽

2020 ◽

Vol 117 (7) ◽

pp. 3603-3609 ◽

Cited By ~ 9

Author(s):

Fan Zou ◽

Renjun Tu ◽

Bo Duan ◽

Zhenlin Yang ◽

Zhaohua Ping ◽

...

Keyword(s):

Stem Cell ◽

Rna Binding ◽

Germ Line ◽

Adult Stem Cell ◽

Cell Development ◽

Rna Modification ◽

Proliferation And Differentiation ◽

Germ Line Stem Cell ◽

Rna Complex

5-Methylcytosine (m5C) is a RNA modification that exists in tRNAs and rRNAs and was recently found in mRNAs. Although it has been suggested to regulate diverse biological functions, whether m5C RNA modification influences adult stem cell development remains undetermined. In this study, we show that Ypsilon schachtel (YPS), a homolog of human Y box binding protein 1 (YBX1), promotes germ line stem cell (GSC) maintenance, proliferation, and differentiation in the Drosophila ovary by preferentially binding to m5C-containing RNAs. YPS is genetically demonstrated to function intrinsically for GSC maintenance, proliferation, and progeny differentiation in the Drosophila ovary, and human YBX1 can functionally replace YPS to support normal GSC development. Highly conserved cold-shock domains (CSDs) of YPS and YBX1 preferentially bind to m5C RNA in vitro. Moreover, YPS also preferentially binds to m5C-containing RNAs, including mRNAs, in germ cells. The crystal structure of the YBX1 CSD-RNA complex reveals that both hydrophobic stacking and hydrogen bonds are critical for m5C binding. Overexpression of RNA-binding–defective YPS and YBX1 proteins disrupts GSC development. Taken together, our findings show that m5C RNA modification plays an important role in adult stem cell development.

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Control of Adult Stem Cell Function in Bioengineered Artificial Niches

Advances in Tissue Engineering ◽

10.1142/9781848161832_0009 ◽

2008 ◽

pp. 175-197

Author(s):

Matthias P. Lutolf ◽

Helen M. Blau

Keyword(s):

Stem Cell ◽

Cell Function ◽

Adult Stem Cell

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Dynamic Mechanical Properties Control Adult Stem Cell Fate

ASME 2012 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2012-80062 ◽

2012 ◽

Author(s):

Murat Guvendiren ◽

Jason A. Burdick

Keyword(s):

Stem Cell ◽

Cell Fate ◽

Adult Stem Cell ◽

Dynamic Mechanical Properties ◽

Cellular Functions ◽

Cellular Processes ◽

Proliferation And Differentiation ◽

Important Field ◽

Control Adult

Stem cells respond to many microenvironmental cues towards their decisions to spread, migrate, and differentiate and these cues can be incorporated into materials for regenerative medicine.1 In the last decade, matrix stiffness alone has been implicated in regulating cellular functions such as migration, proliferation and differentiation. With this in mind, a variety of natural and synthetic polymer systems were used in vitro to mimic the elasticity of native tissues. Despite helping to develop this important field and gather valuable information, these substrates are primarily static and lack the dynamic nature that is observed during many cellular processes such as development, fibrosis and cancer. Thus, it is of great interest to temporally manipulate matrix elasticity in vitro to better understand and develop strategies to control these biological processes. In this work, we utilize a sequential crosslinking approach (initial gelation via addition reaction, secondary crosslinking through light-mediated radical polymerization) to fabricate hydrogel substrates that stiffen (e.g., ∼3 to 30 kPa) either immediately or at later times and in the presence of cells. We demonstrate the utility of this technique by investigating the short-term (several minutes to hours) and long-term (several days to weeks) stem cell response to dynamic stiffening

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Do not keep it simple: recent advances in the generation of complex organoids

Journal of Neural Transmission ◽

10.1007/s00702-020-02198-8 ◽

2020 ◽

Vol 127 (11) ◽

pp. 1569-1577 ◽

Cited By ~ 1

Author(s):

Philipp Wörsdörfer ◽

Takashi I ◽

Izumi Asahina ◽

Yoshinori Sumita ◽

Süleyman Ergün

Keyword(s):

Stem Cell ◽

3D Cell Culture ◽

Adult Stem Cell ◽

Inflammatory Cells ◽

Stem Cell Population ◽

Special Focus ◽

Differentiation Protocol ◽

Organ Specific ◽

Culture Models

Abstract 3D cell culture models which closely resemble real human tissues are of high interest for disease modelling, drug screening as well as a deeper understanding of human developmental biology. Such structures are termed organoids. Within the last years, several human organoid models were described. These are usually stem cell derived, arise by self-organization, mimic mechanisms of normal tissue development, show typical organ morphogenesis and recapitulate at least some organ specific functions. Many tissues have been reproduced in vitro such as gut, liver, lung, kidney and brain. The resulting entities can be either derived from an adult stem cell population, or generated from pluripotent stem cells using a specific differentiation protocol. However, many organoid models only recapitulate the organs parenchyma but are devoid of stromal components such as blood vessels, connective tissue and inflammatory cells. Recent studies show that the incorporation of endothelial and mesenchymal cells into organoids improved their maturation and might be required to create fully functional micro-tissues, which will allow deeper insights into human embryogenesis as well as disease development and progression. In this review article, we will summarize and discuss recent works trying to incorporate stromal components into organoids, with a special focus on neural organoid models.

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