scholarly journals The common YAP activation mediates corneal epithelial regeneration and repair with different-sized wounds

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Yijian Li ◽  
Lingling Ge ◽  
Xia Chen ◽  
Yumei Mao ◽  
Xianliang Gu ◽  
...  

AbstractRegeneration/repair after injury can be endowed by adult stem cells (ASCs) or lineage restricted and even terminally differentiated cells. In corneal epithelium, regeneration after a large wound depends on ASCs (limbal epithelial stem cells, LESCs), whereas repair after a small wound is LESCs-independent. Here, using rat corneal epithelial wounds with different sizes, we show that YAP activation promotes the activation and expansion of LESCs after a large wound, as well as the reprogramming of local epithelial cells (repairing epithelial cells) after a small wound, which contributes to LESCs-dependent and -independent wound healing, respectively. Mechanically, we highlight that the reciprocal regulation of YAP activity and the assembly of cell junction and cortical F-actin cytoskeleton accelerates corneal epithelial healing with different-sized wounds. Together, the common YAP activation and the underlying regulatory mechanism are harnessed by LESCs and lineage-restricted epithelial cells to cope with corneal epithelial wounds with different sizes.

2020 ◽  
Vol 21 (21) ◽  
pp. 7834
Author(s):  
Kasem Theerakittayakorn ◽  
Hong Thi Nguyen ◽  
Jidapa Musika ◽  
Hataiwan Kunkanjanawan ◽  
Sumeth Imsoonthornruksa ◽  
...  

Deficiency of corneal epithelium causes vision impairment or blindness in severe cases. Transplantation of corneal epithelial cells is an effective treatment but the availability of the tissue source for those cells is inadequate. Stem cells can be induced to differentiate to corneal epithelial cells and used in the treatment. Multipotent stem cells (mesenchymal stem cells) and pluripotent stem cells (embryonic stem cells and induced pluripotent stem cells) are promising cells to address the problem. Various protocols have been developed to induce differentiation of the stem cells into corneal epithelial cells. The feasibility and efficacy of both human stem cells and animal stem cells have been investigated for corneal epithelium regeneration. However, some physiological aspects of animal stem cells are different from those of human stem cells, the protocols suited for animal stem cells might not be suitable for human stem cells. Therefore, in this review, only the investigations of corneal epithelial differentiation of human stem cells are taken into account. The available protocols for inducing the differentiation of human stem cells into corneal epithelial cells are gathered and compared. Also, the pathways involving in the differentiation are provided to elucidate the relevant mechanisms.


2020 ◽  
Vol 15 (3) ◽  
pp. 1409-1426 ◽  
Author(s):  
Núria Nieto-Nicolau ◽  
Beatriz Martín-Antonio ◽  
Claudia Müller-Sánchez ◽  
Ricardo P Casaroli-Marano

Aim: To determine the potential of mesenchymal stem cells (MSC) for corneal epithelial regeneration in vitro. Materials & methods: Bone marrow MSC (BM-MSC) and adipose tissue MSC were analyzed for corneal epithelial and mesenchymal markers, using limbal stem cells and corneal cells as controls. MSC with better potential were cultured with specific mediums for epithelial induction. Transepithelial electric resistance and wound healing assay with human corneal epithelial cells were performed. Results: BM-MSC showed better potential, increased corneal markers, and higher transepithelial electric resistance values when induced with limbal epithelial culture medium. Induced BM-MSC promoted better wound healing of human corneal epithelial cells by paracrine secretion. Conclusion: BM-MSC has potential for corneal epithelial induction in a protocol compatible with human application.


2020 ◽  
Author(s):  
Hui Zhu ◽  
Wei Wang ◽  
Lingjuan Xu ◽  
Menglin Jiang ◽  
Yongyao Tan ◽  
...  

ABSTRACTPurposeTo investigate the possibility and the key factors of stably committed mature corneal epithelial cells dedifferentiate into corneal epithelial stem cells in vitro.MethodsMature cornea epithelia cell (MCEC) sheets or limbal epithelial progenitor cell (LEPC) sheets were isolated from central corneas or limbal segments by Dispase II and further digested with 0.25% trypsin/1 mM EDTA (T/E) to yield single cells. Limbal niche cells (LNC) were isolated from the limbal stroma by collagenase A and expanded on 5% Matrigel coated plastic. Single MCECs were seeded on 50% Matrigel with or without LNC culturing for 10 days, regarding as three-dimensional MCEC (3D-MCEC) group or three-dimensional MCEC+LNC (3D-MCEC+LNC) group. Expression of CK12, p63α, PCK, Vimentin were analyzed with immunofluorescence staining.ResultsThe expression of mature cornea epithelial marker (CK12) in MCEC was higher than that in LEPC (P=0.020) but epithelial stem cell marker (p63α) was lower than that in LEPC (P=0.000). When seeded in 3D Matrigel, single MCEC cells could form spheres within 72 hours, and the expression of CK12 reduced (P=0.005) and the expression of p63α also reduced to zero (P=0.000) compared to MCEC. Serial passages of LNC which were expanded in coated Matrigel could form spheres in 3D Matrigel. After mixing MCECs with LNC, rounder spheres emerged within 24 hours which consisted of both epithelia cells (PCK+/Vim-) and LNC (PCK-/Vim+). Moreover, epithelia cells in 3D-MCEC+LNC group expressed less CK12 and more p63α than those in MCEC group (P=0.043, 0.000). Besides, the diameter of spheres in 3D-MCEC+LNC group were larger than that in 3D-MCEC group (P=0.000).ConclusionHuman LNC and three-dimensional Matrigel could induce the dedifferentiation of mature corneal epithelial cells into corneal epithelial stem cells.


2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 7022-7022
Author(s):  
R. Koratkar ◽  
U. Lakshmipathy ◽  
Y. Jiang ◽  
T. Kaur ◽  
B. Slater ◽  
...  

7022 Background: Pneumonitis and pulmonary damage are common toxicities of chest radiation therapy (RT), which may be reduced by transplantation of stem cells that differentiate into pulmonary epithelium. Multipotent Adult Progenitor Cells (MAPC) are adult bone marrow (BM) derived cells, which after IV injection in NOD-SCID mice, differentiate into epithelial and hematopoietic tissues (Nature 418:41). Here we tested the ability of mouse (m) MAPC to regenerate epithelia after RT, in Fanconi Anemia C (FAC) mouse model, which inherently has DNA repair defects and is over sensitive to DNA-cross linking agents. Methods: One million, enhanced-green fluorescent protein (eGFP)- expressing, wild-type mMAPC were injected IV in FAC mice, 4–24 hours after 7.5 Gy (followed by mitomycin C {MMC} 0.1mg/kg/week X 4 in a subset) or 11 Gy RT. Non-eGFP expressing BM was co-transplanted after myeloablative (11 Gy) RT. BM, lungs, intestine and liver of the recipients were analyzed 3–10 months post-transplant for eGFP+ cells and epithelial (CK+) or hematopoietic (CD45+) differentiation using flowcytometry (BM) & immunohistochemistry. Control FAC mice were identically treated but without MAPC. Results: MAPC engraftment (>1% eGFP+ cells) was absent in all control mice. Following 7.5 Gy RT, autologous BM recovery occurred in all (N=10) mice and 1 mouse had 2.7% donor-derived hematopoietic (eGFP+/CD45+) cells after MMC. In both recipients of 11Gy RT, analyzed 9–10 months post-transplant, 5–7% of all CD45+ BM cells were donor MAPC-derived. No donor MAPC-derived epithelial cells were seen in the intestine or liver. However, lungs of most recipients had clusters of donor MAPC-derived epithelial cells, estimated to comprise 1–8% of all pulmonary epithelial cells, consistent with homing of MAPC in lungs following IV injection and their epithelial differentiation in the post-radiation, regenerative, pulmonary micro- environment. The highest degree of MAPC-derived pulmonary regeneration was seen following 11Gy RT that was persistent at 10 months post- transplant. Conclusions: Following radiation, IV injected mMAPC differentiate into hematopoietic and pulmonary epithelial cells that persist long-term. MAPC transplantation has the potential for reducing radiation-induced pulmonary toxicity. No significant financial relationships to disclose.


2021 ◽  
Vol 12 ◽  
Author(s):  
Nongthombam Boby ◽  
Xuewei Cao ◽  
Alyssa Ransom ◽  
Barcley T. Pace ◽  
Christopher Mabee ◽  
...  

Epithelial cell injury and impaired epithelial regeneration are considered key features in HIV pathogenesis and contribute to HIV-induced generalized immune activation. Understanding the molecular mechanisms underlying the disrupted epithelial regeneration might provide an alternative approach for the treatment of HIV-mediated enteropathy and immune activation. We have observed a significant increased presence of α defensin5+ (HD5) Paneth cells and proliferating Ki67+ epithelial cells as well as decreased expression of E-cadherin expression in epithelial cells during SIV infection. SIV infection did not significantly influence the frequency of LGR5+ stem cells, but the frequency of HD5+ cells was significantly higher compared to uninfected controls in jejunum. Our global transcriptomics analysis of enteroids provided novel information about highly significant changes in several important pathways like metabolic, TCA cycle, and oxidative phosphorylation, where the majority of the differentially expressed genes were downregulated in enteroids grown from chronically SIV-infected macaques compared to the SIV-uninfected controls. Despite the lack of significant reduction in LGR5+ stem cell population, the dysregulation of several intestinal stem cell niche factors including Notch, mTOR, AMPK and Wnt pathways as well as persistence of inflammatory cytokines and chemokines and loss of epithelial barrier function in enteroids further supports that SIV infection impacts on epithelial cell proliferation and intestinal homeostasis.


Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 225
Author(s):  
Claire Racaud-Sultan ◽  
Nathalie Vergnolle

In adult stem cells, Glycogen Synthase Kinase 3β (GSK3β) is at the crossroad of signaling pathways controlling survival, proliferation, adhesion and differentiation. The microenvironment plays a key role in the regulation of these cell functions and we have demonstrated that the GSK3β activity is strongly dependent on the engagement of integrins and protease-activated receptors (PARs). Downstream of the integrin α5β1 or PAR2 activation, a molecular complex is organized around the scaffolding proteins RACK1 and β-arrestin-2 respectively, containing the phosphatase PP2A responsible for GSK3β activation. As a consequence, a quiescent stem cell phenotype is established with high capacities to face apoptotic and metabolic stresses. A protective role of GSK3β has been found for hematopoietic and intestinal stem cells. Latters survived to de-adhesion through PAR2 activation, whereas formers were protected from cytotoxicity through α5β1 engagement. However, a prolonged activation of GSK3β promoted a defect in epithelial regeneration and a resistance to chemotherapy of leukemic cells, paving the way to chronic inflammatory diseases and to cancer resurgence, respectively. In both cases, a sexual dimorphism was measured in GSK3β-dependent cellular functions. GSK3β activity is a key marker for inflammatory and cancer diseases allowing adjusted therapy to sex, age and metabolic status of patients.


Biomedicines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 873
Author(s):  
Ovidiu Samoila ◽  
Lacramioara Samoila

The future of eye reconstruction invariably includes stem cells transplantation. Corneal limbus, corneal stroma, trabeculum, retinal cells, optic nerve, and all structures that are irreversibly damaged and have no means to be repaired or replaced, through conventional treatment or surgery, represent targets for stem cell reconstruction. This review tries to answer the question if there is any clinical validation for stem therapies, so far, starting from the cornea and, on the path of light, arriving to the retina. The investigation covers the last 10 years of publications. From 2385 published sources, we found 56 clinical studies matching inclusion criteria, 39 involving cornea, and 17 involving retina. So far, corneal epithelial reconstruction seems well validated clinically. Enough clinical data are collected to allow some form of standardization for the stem cell transplant procedures. Cultivated limbal epithelial stem cells (CLET), simple limbal epithelial transplant (SLET), and oral mucosa transplantation are implemented worldwide. In comparison, far less patients are investigated in retinal stem reconstructions, with lower anatomical and clinical success, so far. Intravitreal, subretinal, and suprachoroidal approach for retinal stem therapies face specific challenges.


2012 ◽  
Vol 303 (11) ◽  
pp. G1188-G1201 ◽  
Author(s):  
Kevin R. Hughes ◽  
Ricardo M. C. Gândara ◽  
Tanvi Javkar ◽  
Fred Sablitzky ◽  
Hanno Hock ◽  
...  

Stem cells have been identified in two locations in small intestinal crypts; those intercalated between Paneth cells and another population (which retains DNA label) are located above the Paneth cell zone, at cell position 4. Because of disadvantages associated with the use of DNA label, doxycycline-induced transient transgenic expression of histone 2B (H2B)-green fluorescent protein (GFP) was investigated. H2B-GFP-retaining putative stem cells were consistently seen, with a peak at cell position 4, over chase periods of up to 112 days. After a 28-day chase, a subpopulation of the H2B-GFP-retaining cells was cycling, but the slow cycling status of the majority was illustrated by lack of expression of pHistone H3 and Ki67. Although some H2B-GFP-retaining cells were sensitive to low-dose radiation, the majority was resistant to low- and high-dose radiation-induced cell death, and a proportion of the surviving cells proliferated during subsequent epithelial regeneration. Long-term retention of H2B-GFP in a subpopulation of small intestinal Paneth cells was also seen, implying that they are long lived. In contrast to the small intestine, H2B-GFP-retaining epithelial cells were not seen in the colon from 28-day chase onward. This implies important differences in stem cell function between these two regions of the gastrointestinal tract, which may have implications for region-specific susceptibility to diseases (such as cancer and ulcerative colitis), in which epithelial stem cells and their progeny are involved.


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