scholarly journals Keratinocyte desmoglein 1 regulates the epidermal microenvironment and tanning response

2018 ◽  
Author(s):  
Christopher R. Arnette ◽  
Jennifer L. Koetsier ◽  
Joshua A. Broussard ◽  
Pedram Gerami ◽  
Jodi L. Johnson ◽  
...  

ABSTRACTCoordinated responses to environmental stimuli within the keratinocyte:melanocyte niche are poorly understood. Desmoglein 1 (Dsg1), a keratinocyte-specific desmosomal cell-cell adhesion protein with emerging signaling roles, is reduced by ultraviolet light radiation. Loss-of-function Dsg1 mutations elevate keratinocyte cytokines in Severe dermatitis, multiple Allergies, and Metabolic wasting (SAM) syndrome. We asked whether Dsg1 regulates keratinocyte:melanocyte paracrine communication to induce the tanning response. Dsg1-silenced keratinocytes increasedPro-opiomelanocortinmRNA and cytokine secretion. Melanocytes treated with conditioned media from Dsg1-silenced keratinocytes exhibited increasedMitfandTrp1mRNA, melanin secretion, and dendrite length. Inhibiting the melanocyte pigment-associated melanocortin 1 receptor reduced pigment secretion in response to Dsg1-deficient conditioned media. Melanocytes incorporated into Dsg1-deficient human skin equivalents relocalized suprabasally, reminiscent of early melanoma pagetoid behavior. Dsg1 decreased in keratinocytes surrounding dysplastic nevi and early melanoma, but not benign nevi. We posit Dsg1 controls keratinocyte:melanocyte communication through paracrine signaling, which goes awry upon Dsg1 loss in melanoma development.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Nurul Dinah Kadir ◽  
Zheng Yang ◽  
Afizah Hassan ◽  
Vinitha Denslin ◽  
Eng Hin Lee

Abstract Background Secretome profiles of mesenchymal stem cells (MSCs) are reflective of their local microenvironments. These biologically active factors exert an impact on the surrounding cells, eliciting regenerative responses that create an opportunity for exploiting MSCs towards a cell-free therapy for cartilage regeneration. The conventional method of culturing MSCs on a tissue culture plate (TCP) does not provide the physiological microenvironment for optimum secretome production. In this study, we explored the potential of electrospun fiber sheets with specific orientation in influencing the MSC secretome production and its therapeutic value in repairing cartilage. Methods Conditioned media (CM) were generated from MSCs cultured either on TCP or electrospun fiber sheets of distinct aligned or random fiber orientation. The paracrine potential of CM in affecting chondrogenic differentiation, migration, proliferation, inflammatory modulation, and survival of MSCs and chondrocytes was assessed. The involvement of FAK and ERK mechanotransduction pathways in modulating MSC secretome were also investigated. Results We showed that conditioned media of MSCs cultured on electrospun fiber sheets compared to that generated from TCP have improved secretome yield and profile, which enhanced the migration and proliferation of MSCs and chondrocytes, promoted MSC chondrogenesis, mitigated inflammation in both MSCs and chondrocytes, as well as protected chondrocytes from apoptosis. Amongst the fiber sheet-generated CM, aligned fiber-generated CM (ACM) was better at promoting cell proliferation and augmenting MSC chondrogenesis, while randomly oriented fiber-generated CM (RCM) was more efficient in mitigating the inflammation assault. FAK and ERK signalings were shown to participate in the modulation of MSC morphology and its secretome production. Conclusions This study demonstrates topographical-dependent MSC paracrine activities and the potential of employing electrospun fiber sheets to improve the MSC secretome for cartilage regeneration.


Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 2005
Author(s):  
Irene Vorontsova ◽  
James E. Hall ◽  
Thomas F. Schilling ◽  
Noriaki Nagai ◽  
Yosuke Nakazawa

Aquaporin 0 (AQP0) is the most abundant lens membrane protein, and loss of function in human and animal models leads to cataract formation. AQP0 has several functions in the lens including water transport and adhesion. Since lens optics rely on strict tissue architecture achieved by compact cell-to-cell adhesion between lens fiber cells, understanding how AQP0 contributes to adhesion would shed light on normal lens physiology and pathophysiology. We show in an in vitro adhesion assay that one of two closely related zebrafish Aqp0s, Aqp0b, has strong auto-adhesive properties while Aqp0a does not. The difference appears to be largely due to a single amino acid difference at residue 110 in the extracellular C-loop, which is T in Aqp0a and N in Aqp0b. Similarly, P110 is the key residue required for adhesion in mammalian AQP0, highlighting the importance of residue 110 in AQP0 cell-to-cell adhesion in vertebrate lenses as well as the divergence of adhesive and water permeability functions in zebrafish duplicates.


Author(s):  
Chukwuweike Gwam ◽  
Ahmed Emara ◽  
Nequesha Mohamed ◽  
Noor Chughtai ◽  
Johannes Plate ◽  
...  

Muscle and nerve tissue damage can elicit a significant loss of function and poses as a burden for patients and healthcare providers. Even for tissues, such as the peripheral nerve and skeletal muscle, that harbor significant regenerative capacity, innate regenerative processes often lead to less than optimal recovery and residual loss of function. The reasons for poor regeneration include significant cell damage secondary to oxidative stress, poor recruitment of resident stem cells, and an unfavorable microenvironment for tissue regeneration. Stem cell-based therapy was once thought as a potential therapy in tissue regeneration, due to its self-renewal and multipotent capabilities. Early advocates for cellular-based therapy pointed to the pluripotent nature of stem cells, thus eluding to its ability to differentiate into resident cells as the source of its regenerative capability. However, increasing evidence has revealed a lack of engraftment and differentiation of stem cells, thereby pointing to stem cell paracrine activity as being responsible for its regenerative potential. Stem cell-conditioned media houses biomolecular factors that portray significant regenerative potential. Amniotic-derived stem cell-conditioned media (AFS-CM) has been of particular interest because of its ease of allocation and in vitro culture. The purpose of this review is to report the results of studies that assess the role of AFS-CM for nerve and muscle conditions. In this review, we will cover the effects of AFS-CM on cellular pathways, genes, and protein expression for different nerve and muscle cell types.


2018 ◽  
Author(s):  
María I. Lázaro-Peña ◽  
Carlos A. Díaz-Balzac ◽  
Hannes E. Bülow ◽  
Scott W. Emmons

AbstractThe nervous system regulates complex behaviors through a network of neurons interconnected by synapses. How specific synaptic connections are genetically determined is still unclear. Male mating is the most complex behavior in C. elegans. It is composed of sequential steps that are governed by more than 3,000 chemical connections. Here we show that heparan sulfates (HS) play a role in the formation and function of the male neural network. Cell-autonomous and non-autonomous 3-O sulfation by the HS modification enzyme HST-3.1/HS 3-O-sulfotransferase, localized to the HSPG glypicans LON-2/glypican and GPN-1/glypican, was specifically required for response to hermaphrodite contact during mating. Loss of 3-O sulfation resulted in the presynaptic accumulation of RAB-3, a molecule that localizes to synaptic vesicles, disrupting the formation of synapses in a component of the mating circuits. We also show that neural cell adhesion protein neurexin promotes and neural cell adhesion protein neuroligin inhibits formation of the same set of synapses in a parallel pathway. Thus, neural cell adhesion proteins and extracellular matrix components act together in the formation of synaptic connections.Author SummaryThe formation of the nervous system requires the function of several genetically-encoded proteins to form complex networks. Enzymatically-generated modifications of these proteins play a crucial role during this process. These authors analyzed the role of heparan sulfates in the process of synaptogenesis in the male tail of C. elegans. A modification of heparan sulfate is required for the formation of specific synapses between neurons by acting cell-autonomously and non-autonomously. Could it be that heparan sulfates and their diverse modifications are a component of the specification factor that neurons use to make such large numbers of connections unique?


2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Jie Liu ◽  
Yanmei Qi ◽  
Shu-Chan Hsu ◽  
Siavash Saadat ◽  
Saum Rahimi ◽  
...  

Cellular repressor of E1A-stimulated genes 1 (CREG1) is a 24 kD glycoprotein essential for early embryonic development. Our immunofluorescence studies revealed that CREG1 is highly expressed at myocyte junctions in both embryonic and adult hearts. To explore it role in cardiomyogenesis, we employed gain- and loss-of-function analyses demonstrating that CREG1 is required for the differentiation of mouse embryonic stem (ES) cell into cohesive myocardium-like structures. Chimeric cultures of wild-type and CREG1 knockout ES cells expressing cardiac-specific reporters showed that the cardiomyogenic effect of CREG1 is cell autonomous. Furthermore, we identified a novel interaction between CREG1 and Sec8 of the exocyst complex, which tethers vesicles to the plasma membrane. Mutations of the amino acid residues D141 and P142 to alanine in CREG1 abolished its binding to Sec8. To address the role of the CREG1-Sec8 interaction in cardiomyogenesis, we rescued CREG1 knockout ES cells with wild-type and Sec8-binding mutant CREG1 and showed that CREG1 binding to Sec8 promotes cardiomyocyte differentiation and cohesion. Mechanistically, CREG1, Sec8 and N-cadherin all localize at cell-cell adhesion sites. CREG1 overexpression enhances the assembly of adherens and gap junctions. By contrast, its knockout inhibits the Sec8-N-cadherin interaction and induces their degradation. Finally, shRNA-mediated knockdown of Sec8 leads to cardiomyogenic defects similar to CREG1 knockout. These results suggest that the CREG1 binding to Sec8 enhances the assembly of intercellular junctions and promotes cardiomyogenesis.


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