scholarly journals Osteoporosis-decreased extracellular matrix stiffness impairs connexin 43-mediated gap junction intercellular communication in osteocytes

2020 ◽  
Vol 52 (5) ◽  
pp. 517-526
Author(s):  
Demao Zhang ◽  
Xin Li ◽  
Caixia Pi ◽  
Linyi Cai ◽  
Yang Liu ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Extracellular Matrix ◽  
Mouse Model ◽  
Gap Junctions ◽  
Gap Junction ◽  
Intercellular Communication ◽  
Cell Communication ◽  
Matrix Stiffness ◽  
Gap Junction Intercellular Communication

Abstract Osteocytes are the main sensitive and responsive cells for mechanical stimuli in bone. The connexin family enables them to communicate with each other via forming functional gap junctions. However, how osteoporosis-impaired extracellular mechanical property modulates gap junction intercellular communication in osteocytes remains elusive. In this study, we established an ovariectomy (OVX)-induced osteoporosis mouse model in vivo and a polydimethylsiloxane (PDMS)-based cell culture substrate model in vitro to explore the influence of extracellular matrix (ECM) stiffness on cell-to-cell communication in osteocytes. Firstly, we established an OVX-induced osteoporosis mouse model by characterizing the changes in radiography, morphology and histochemistry of femurs. Our results showed that osteoporosis decreased the bone matrix stiffness together with the changes including the loss of osteocytes and the decrease of protein markers. Meanwhile, the dendritic process interconnection and channel-forming protein, Cx43, were reduced in osteoporosis mice. Next we mimicked ECM stiffness changes in vitro by using PDMS substrates at ratios 1:5 for normal stiffness and 1:45 for osteoporosis stiffness. Our results showed that the decreased ECM stiffness reduced the number of dendritic processes in a single cell and gap junctions between adjacent osteocytes. We further detected the decreased expression of Cx43, in the substrate with decreased stiffness. Finally, we found that gap junction-based intercellular communication was reduced in living osteocytes in the substrate with decreased stiffness. This study demonstrates the correlation between ECM mechanical property and cell-to-cell communication in osteocytes and might pave the way for further exploration of osteoporosis in terms of biomechanics.

Connexin expression by alveolar epithelial cells is regulated by extracellular matrix

2001 ◽  
Vol 280 (2) ◽  
pp. L191-L202 ◽  
Author(s):  
Yihe Guo ◽  
Cara Martinez-Williams ◽  
Clare E. Yellowley ◽  
Henry J. Donahue ◽  
D. Eugene Rannels
Keyword(s):  
Extracellular Matrix ◽  
Epithelial Cells ◽  
Gap Junction ◽  
Intercellular Communication ◽  
Translational Regulation ◽  
Alveolar Epithelial Cells ◽  
Alveolar Type ◽  
Type Ii ◽  
Gap Junction Intercellular Communication ◽  
Type Ii Cell

Extracellular matrix (ECM) proteins promote attachment, spreading, and differentiation of cultured alveolar type II epithelial cells. The present studies address the hypothesis that the ECM also regulates expression and function of gap junction proteins, connexins, in this cell population. Expression of cellular fibronectin and connexin (Cx) 43 increase in parallel during early type II cell culture as Cx26 expression declines. Gap junction intercellular communication is established over the same interval. Cells plated on a preformed, type II cell-derived, fibronectin-rich ECM demonstrate accelerated formation of gap junction plaques and elevated gap junction intercellular communication. These effects are blocked by antibodies against fibronectin, which cause redistribution of Cx43 protein from the plasma membrane to the cytoplasm. Conversely, cells cultured on a laminin-rich ECM, Matrigel, express low levels of Cx43 but high levels of Cx26, reflecting both transcriptional and translational regulation. Cx26 and Cx43 thus demonstrate reciprocal regulation by ECM constituents.

scholarly journals Regulation of gap junction intercellular communication by connexin ubiquitination: physiological and pathophysiological implications

2019 ◽  
Vol 77 (4) ◽  
pp. 573-591 ◽  
Author(s):  
Max Zachrisson Totland ◽  
Nikoline Lander Rasmussen ◽  
Lars Mørland Knudsen ◽  
Edward Leithe
Keyword(s):  
Gap Junctions ◽  
Gap Junction ◽  
Intercellular Communication ◽  
Gap Junction Channels ◽  
Gap Junction Intercellular Communication ◽  
Endocytic Sorting ◽  
Intercellular Channels ◽  
Specific Tissue ◽  
Dynamic Structures ◽  
Made In

Abstract Gap junctions consist of arrays of intercellular channels that enable adjacent cells to communicate both electrically and metabolically. Gap junctions have a wide diversity of physiological functions, playing critical roles in both excitable and non-excitable tissues. Gap junction channels are formed by integral membrane proteins called connexins. Inherited or acquired alterations in connexins are associated with numerous diseases, including heart failure, neuropathologies, deafness, skin disorders, cataracts and cancer. Gap junctions are highly dynamic structures and by modulating the turnover rate of connexins, cells can rapidly alter the number of gap junction channels at the plasma membrane in response to extracellular or intracellular cues. Increasing evidence suggests that ubiquitination has important roles in the regulation of endoplasmic reticulum-associated degradation of connexins as well as in the modulation of gap junction endocytosis and post-endocytic sorting of connexins to lysosomes. In recent years, researchers have also started to provide insights into the physiological roles of connexin ubiquitination in specific tissue types. This review provides an overview of the advances made in understanding the roles of connexin ubiquitination in the regulation of gap junction intercellular communication and discusses the emerging physiological and pathophysiological implications of these processes.

Connexin 43 ubiquitination determines the fate of gap junctions: restrict to survive

2015 ◽  
Vol 43 (3) ◽  
pp. 471-475 ◽  
Author(s):  
Teresa M. Ribeiro-Rodrigues ◽  
Steve Catarino ◽  
Maria J. Pinho ◽  
Paulo Pereira ◽  
Henrique Girao
Keyword(s):  
Plasma Membrane ◽  
Gap Junctions ◽  
Gap Junction ◽  
Intercellular Communication ◽  
Connexin 43 ◽  
Transmembrane Proteins ◽  
Post Translational Modifications ◽  
Gap Junction Intercellular Communication

Connexins (Cxs) are transmembrane proteins that form channels which allow direct intercellular communication (IC) between neighbouring cells via gap junctions. Mechanisms that modulate the amount of channels at the plasma membrane have emerged as important regulators of IC and their de-regulation has been associated with various diseases. Although Cx-mediated IC can be modulated by different mechanisms, ubiquitination has been described as one of the major post-translational modifications involved in Cx regulation and consequently IC. In this review, we focus on the role of ubiquitin and its effect on gap junction intercellular communication.

IL-1β-induced production of metalloproteinases by synovial cells depends on gap junction conductance

2002 ◽  
Vol 282 (6) ◽  
pp. C1254-C1260 ◽  
Author(s):  
Oleg V. Kolomytkin ◽  
Andrew A. Marino ◽  
David D. Waddell ◽  
J. Michael Mathis ◽  
Robert E. Wolf ◽  
...  
Keyword(s):  
Gap Junctions ◽  
Gap Junction ◽  
Intercellular Communication ◽  
Biological Function ◽  
Synovial Cells ◽  
Gap Junction Intercellular Communication ◽  
Dose Dependent Increase ◽  
Dose Dependent ◽  
Junction Conductance

Synovial cells can form networks connected by gap junctions. The purpose of this study was to obtain evidence for a necessary role of gap junction intercellular communication in protein secretion by synovial cells. We developed a novel assay to measure the enzymatic activity of metalloproteinases (MMPs) produced by synovial cells in response to interleukin-1β (IL-1β) and employed the assay to explore the biological function of gap junctions. IL-1β produced a dose-dependent increase in MMP activity that was blocked by exposure to the gap junction inhibitors 18α-glycyrrhetinic acid and octanol for as few as 50 min. The inhibitors produced an immediate and marked reduction in intercellular communication, as assessed by transient current analysis using the nystatin perforated-patch method. These observations suggest that communication through gap junctions early in IL-1β signal transduction is critical to the process of cytokine-regulated secretion of MMPs by synovial cells.

Gap junctional intercellular communication in the juxtaglomerular apparatus

2009 ◽  
Vol 296 (5) ◽  
pp. F939-F946 ◽  
Author(s):  
Jian Yao ◽  
Takashi Oite ◽  
Masanori Kitamura
Keyword(s):  
Gap Junctions ◽  
Gap Junction ◽  
Intercellular Communication ◽  
Mesangial Cells ◽  
Contact Region ◽  
Ion Homeostasis ◽  
Cell Communication ◽  
Juxtaglomerular Apparatus ◽  
Thick Ascending Limb ◽  
Gap Junctional Intercellular Communication

The juxtaglomerular apparatus (JGA) is a specialized contact region between the glomerulus and the cortical thick ascending limb that plays an active role in the maintenance of ion homeostasis and control of blood pressure. The JGA accommodates several different cell types, including vascular smooth muscle cells, endothelial cells, mesangial cells, macula densa cells, and renin-secreting juxtaglomerular granular cells. These cells, with the exception of the macular densa cells, are tightly coupled by gap junctions. Gap junction-mediated intercellular communication in the JGA provides a pathway for signal transduction and coordination of multicellular functions. Disruption of cell-to-cell communication in the JGA results in altered preglomerular vascular tone and renin secretion. This review summarizes recent data about the roles of gap junctions in the JGA and illustrates how gap junction-mediated intercellular Ca2+signals determine physiological responses in the JGA.

scholarly journals Gap Junction-Mediated Intercellular Communication of cAMP Prevents CDDP-Induced Ototoxicity via cAMP/PKA/CREB Pathway

2021 ◽  
Vol 22 (12) ◽  
pp. 6327
Author(s):  
Yeon-Ju Kim ◽  
Jin-Sol Lee ◽  
Hantai Kim ◽  
Jeong-Hun Jang ◽  
Yun-Hoon Choung
Keyword(s):  
Cell Death ◽  
Gap Junctions ◽  
Small Molecules ◽  
Gap Junction ◽  
Intercellular Communication ◽  
Ex Vivo ◽  
Adenosine Monophosphate ◽  
Supporting Cells

In the cochlea, non-sensory supporting cells are directly connected to adjacent supporting cells via gap junctions that allow the exchange of small molecules. We have previously shown that the pharmacological regulation of gap junctions alleviates cisplatin (CDDP)-induced ototoxicity in animal models. In this study, we aimed to identify specific small molecules that pass through gap junctions in the process of CDDP-induced auditory cell death and suggest new mechanisms to prevent hearing loss. We found that the cyclic adenosine monophosphate (cAMP) inducer forskolin (FSK) significantly attenuated CDDP-induced auditory cell death in vitro and ex vivo. The activation of cAMP/PKA/CREB signaling was observed in organ of Corti primary cells treated with FSK, especially in supporting cells. Co-treatment with gap junction enhancers such as all-trans retinoic acid (ATRA) and quinoline showed potentiating effects with FSK on cell survival via activation of cAMP/PKA/CREB. In vivo, the combination of FSK and ATRA was more effective for preventing ototoxicity compared to either single treatment. Our study provides the new insight that gap junction-mediated intercellular communication of cAMP may prevent CDDP-induced ototoxicity.

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