Microfabricated Grooved Substrates Influence Cell–Cell Communication and Osteoblast Differentiation In Vitro

2009 ◽  
Vol 15 (6) ◽  
pp. 1427-1436 ◽  
Author(s):  
George Kirmizidis ◽  
Mark A. Birch
2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Wenjing Liu ◽  
Demao Zhang ◽  
Xin Li ◽  
Liwei Zheng ◽  
Chen Cui ◽  
...  

Abstract Connexins and pannexins are two families of channel forming proteins that are able to pass small molecules to achieve communication between cells. While connexins have been recognized to mediate gap junctional intercellular communication (GJIC), pannexins are far less known. Our previous study reported the potential role of TGF-β1 in mediating of connexins in osteocytes in vitro. Herein, we aimed to elucidate the influence of TGF-β1 on cell–cell communication based on gap junctions assembled by connexins and pannexins in vitro and ex vivo. We first showed that TGF-β1 positively affected the elongation of dendritic processes of osteocytes. Our data indicated that TGF-β1 increased expressions of connexin43 (Cx43) and pannexin1 (panx1), which are indispensable for hemichannel formation in gap junctions, in osteocytes in vitro and ex vivo. TGF-β1 enhanced gap junction formation and impacted cell–cell communication in living osteocytes, as indicated by the scrape loading and Lucifer yellow transfer assays. TGF-β1 enhanced the expressions of Cx43 and panx1 via activation of ERK1/2 and Smad3/4 signalling. The TGF-β1-restored expressions of Cx43 and panx1 in osteocytes in the presence of an ERK inhibitor, U0126, further demonstrated the direct participation of Smad3/4 signalling. TGF-β1 increased the accumulation of Smad3 in the nuclear region (immunofluorescence assay) and promoted the enrichment of Smad3 at the binding sites of the promoters of Gja1 (Cx43) and Panx1 (ChIP assay), thereby initiating the enhanced gene expression. These results provide a deep understanding of the molecular mechanisms involved in the modulation of cell–cell communication in osteocytes induced by TGF-β1.


2009 ◽  
Vol 296 (5) ◽  
pp. H1694-H1704 ◽  
Author(s):  
Indroneal Banerjee ◽  
John W. Fuseler ◽  
Arti R. Intwala ◽  
Troy A. Baudino

Interleukin-6 (IL-6) is a pleiotropic cytokine responsible for many different processes including the regulation of cell growth, apoptosis, differentiation, and survival in various cell types and organs, including the heart. Recent studies have indicated that IL-6 is a critical component in the cell-cell communication between myocytes and cardiac fibroblasts. In this study, we examined the effects of IL-6 deficiency on the cardiac cell populations, cardiac function, and interactions between the cells of the heart, specifically cardiac fibroblasts and myocytes. To examine the effects of IL-6 loss on cardiac function, we used the IL-6 −/− mouse. IL-6 deficiency caused severe cardiac dilatation, increased accumulation of interstitial collagen, and altered expression of the adhesion protein periostin. In addition, flow cytometric analyses demonstrated dramatic alterations in the cardiac cell populations of IL-6 −/− mice compared with wild-type littermates. We observed a marked increase in the cardiac fibroblast population in IL-6 −/− mice, whereas a concomitant decrease was observed in the other cardiac cell populations examined. Moreover, we observed increased cell proliferation and apoptosis in the developing IL-6 −/− heart. Additionally, we observed a significant decrease in the capillary density of IL-6 −/− hearts. To elucidate the role of IL-6 in the interactions between cardiac fibroblasts and myocytes, we performed in vitro studies and demonstrated that IL-6 deficiency attenuated the activation of the STAT3 pathway and VEGF production. Taken together, these data demonstrate that a loss of IL-6 causes cardiac dysfunction by shifting the cardiac cell populations, altering the extracellular matrix, and disrupting critical cell-cell interactions.


2019 ◽  
Vol 35 (20) ◽  
pp. 4081-4088
Author(s):  
Hosein Fooladi ◽  
Parsa Moradi ◽  
Ali Sharifi-Zarchi ◽  
Babak Hosein Khalaj

Abstract Motivation The molecular mechanisms of self-organization that orchestrate embryonic cells to create astonishing patterns have been among major questions of developmental biology. It is recently shown that embryonic stem cells (ESCs), when cultured in particular micropatterns, can self-organize and mimic the early steps of pre-implantation embryogenesis. A systems-biology model to address this observation from a dynamical systems perspective is essential and can enhance understanding of the phenomenon. Results Here, we propose a multicellular mathematical model for pattern formation during in vitro gastrulation of human ESCs. This model enhances the basic principles of Waddington epigenetic landscape with cell–cell communication, in order to enable pattern and tissue formation. We have shown the sufficiency of a simple mechanism by using a minimal number of parameters in the model, in order to address a variety of experimental observations such as the formation of three germ layers and trophectoderm, responses to altered culture conditions and micropattern diameters and unexpected spotted forms of the germ layers under certain conditions. Moreover, we have tested different boundary conditions as well as various shapes, observing that the pattern is initiated from the boundary and gradually spreads towards the center. This model provides a basis for in-silico modeling of self-organization. Availability and implementation https://github.com/HFooladi/Self_Organization. Supplementary information Supplementary data are available at Bioinformatics online.


Bone ◽  
1994 ◽  
Vol 15 (1) ◽  
pp. 120
Author(s):  
K Schirrmacher ◽  
E Winterhager ◽  
O Traub ◽  
F Brummer ◽  
D Jones ◽  
...  

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Zhengjun Peng ◽  
Lu Liu ◽  
Wenyu Zhang ◽  
Xi Wei

Alternation in culture environment due to cell-cell communications can rejuvenate the biological activity of aged/differentiated cells and stimulate the expression of pluripotency markers. Dental pulp cells (DPCs) and periodontal ligament cells (PDLCs) are promising candidates in dental tissue regeneration. However, the molecular network that underlies cell-cell communications between dental-derived cells and the microenvironment remains to be identified. To elucidate the signaling network that regulates the pluripotency of DPCs and PDLCs, proliferation, apoptosis, cell cycle, and the expression of Oct-4/Sox2/c-Myc in DPCs and PDLCs with indirect/direct coculture were examined. PCR arrays were constructed to identify genes that were differentially expressed, and the results were confirmed by a rat model with injury. Further research on the mechanism of the related signaling pathways was investigated by overexpression/silence of STAT3, ChIP, the dual-luciferase reporter assay, and EMSA. We found that the proliferation and apoptosis of DPCs and PDLCs were inhibited, and their cell cycles were arrested at the G0/G1 phase after coculture. Oct-4, Sox2, and STAT3 expression significantly increased and PAX5 expression decreased in the coculture systems. Oct-4/Sox2/STAT3/PAX5 was actively expressed in the rat defect model. Moreover, STAT3 was directly bound to the Oct-4 and Sox2 gene promoter regions and activated the expression of those genes. Our data showed that the pluripotency of DPCs and PDLCs was enhanced through cell-cell communication. STAT3 plays essential roles in regulating the pluripotency of DPCs and PDLCs by targeting Oct-4 and Sox2 both in vitro and in vivo.


2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Wendy Fitzgerald ◽  
Michael L. Freeman ◽  
Michael M. Lederman ◽  
Elena Vasilieva ◽  
Roberto Romero ◽  
...  

Abstract Cytokines are soluble factors that mediate cell–cell communications in multicellular organisms. Recently, another system of cell–cell communication was discovered, which is mediated by extracellular vesicles (EVs). Here, we demonstrate that these two systems are not strictly separated, as many cytokines in vitro, ex vivo, and in vivo are released in EV-encapsulated forms and are capable of eliciting biological effects upon contact with sensitive cells. Association with EVs is not necessarily a property of a particular cytokine but rather of a biological system and can be changed upon system activation. EV-encapsulated cytokines were not detected by standard cytokine assays. Deciphering the regulatory mechanisms of EV-encapsulation will lead to a better understanding of cell–cell communications in health and disease.


2021 ◽  
Author(s):  
Tomohiro Takagi ◽  
Hirofumi Inoue ◽  
Shungo Fujii ◽  
Nobuyuki Takahashi ◽  
Mariko Uehara

Abstract Objective: Erucin (ERN), an isothiocyanate, is derived from the vegetable arugula. Although ERN has antitumor and antioxidant activity, the effect of ERN on osteoclast and osteoblast differentiation is not well documented. In this study, we evaluated the effects of ERN on osteoclast and osteoblast differentiation in vitro. Results: ERN significantly reduced the formation of 1α,25(OH)2D3-induced tartrate-resistant acid phosphatase (TRAP)-positive cells at non-cytotoxic concentrations. Furthermore, ERN downregulated the mRNA expression of osteoclast-associated genes, such as nuclear factor of activated T cells cytoplasmic-1, TRAP, and cathepsin K. In addition, ERN suppressed dendritic cell specific transmembrane protein (DC-STAMP), which encodes cell-cell fusion. However, ERN did not affect mineralization by osteoblasts. Thus, our data suggest that ERN may attenuate osteoclastic bone resorption by inhibiting multinucleation of mononuclear pre-osteoclasts and by suppressing mRNA expression of DC-STAMP in bone marrow cells without influencing mineralization by osteoblasts.


2016 ◽  
Vol 198 (24) ◽  
pp. 3278-3286 ◽  
Author(s):  
Christina C. Saak ◽  
Karine A. Gibbs

ABSTRACT Proteus mirabilis is a social bacterium that is capable of self (kin) versus nonself recognition. Swarming colonies of this bacterium expand outward on surfaces to centimeter-scale distances due to the collective motility of individual cells. Colonies of genetically distinct populations remain separate, while those of identical populations merge. Ids proteins are essential for this recognition behavior. Two of these proteins, IdsD and IdsE, encode identity information for each strain. These two proteins bind in vitro in an allele-restrictive manner. IdsD-IdsE binding is correlated with the merging of populations, whereas a lack of binding is correlated with the separation of populations. Key questions remained about the in vivo interactions of IdsD and IdsE, specifically, whether IdsD and IdsE bind within single cells or whether IdsD-IdsE interactions occur across neighboring cells and, if so, which of the two proteins is exchanged. Here we demonstrate that IdsD must originate from another cell to communicate identity and that this nonresident IdsD interacts with IdsE resident in the recipient cell. Furthermore, we show that unbound IdsD in recipient cells does not cause cell death and instead appears to contribute to a restriction in the expansion radius of the swarming colony. We conclude that P. mirabilis communicates IdsD between neighboring cells for nonlethal kin recognition, which suggests that the Ids proteins constitute a type of cell-cell communication. IMPORTANCE We demonstrate that self (kin) versus nonself recognition in P. mirabilis entails the cell-cell communication of an identity-encoding protein that is exported from one cell and received by another. We further show that this intercellular exchange affects swarm colony expansion in a nonlethal manner, which adds social communication to the list of potential swarm-related regulatory factors.


2021 ◽  
Vol 13 ◽  
Author(s):  
Luis Alfonso González-Molina ◽  
Juan Villar-Vesga ◽  
Julián Henao-Restrepo ◽  
Andrés Villegas ◽  
Francisco Lopera ◽  
...  

Astrocytes are specialized glial cells that are essential components of the neurovascular unit (NVU) and are involved in neurodevelopment, brain maintenance and repair, and neurodegeneration. Astrocytes mediate these processes by releasing cellular mediators such as extracellular vesicles (EVs). EVs are vehicles of cell-cell communication and have been proposed as mediators of damage in AD. However, the transcellular mechanism by which Alzheimer disease (AD) astrocytes impair the function of NVU components is poorly understood. Therefore, we evaluated the effects of adult PS1-KI and 3xTg-AD astrocyte conditioned media (CM) and EVs on NVU components (neuroglia and endothelium) in vitro. Additionally, SAD and FAD astrocyte-derived EVs (A-EVs) were characterized, and we evaluated their effects on NVU in cocultured cells in vitro and on intrahippocampal CA1 cells in vivo. Surprisingly, cultured 3xTg-AD astrocytes showed increased glial fibrillary acidic protein (GFAP) reactivity compared to PS1-KI astrocytes, which denotes astrocytic hyperreactivity. CM from adult mice 3xTg-AD astrocytes increased cell-cell gaps between endothelial cells, filopodia-like dendritic protrusions in neurons and neuronal and endothelial cell death. 3xTg-AD A-EVs induced neurotoxicity and increased astrocyte GFAP reactivity. Cultured human postmortem astrocytes from AD patients also increased GFAP reactivity and EVs release. No differences in the size or number of A-EVs were detected between AD and control samples; however, both SAD and FAD A-EVs showed increased expression of the surface marker aquaporin 4. A-EVs induced cytotoxicity and astrocyte hyperactivation: specifically, FAD A-EVs induced neuroglial cytotoxicity and increased gaps between the endothelium, while SAD A-EVs mainly altered the endothelium. Similarly, both AD A-EVs increased astrocyte GS reactivity and vascular deterioration in vivo. We associated this finding with perivascular reactive astrocytes and vascular deterioration in the human AD brain. In summary, these results suggest that AD A-EVs impair neuroglial and vascular components.


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