Tight junction proteins: a novel class of integral membrane proteins

2002 ◽  
Vol 294 (1-2) ◽  
pp. 14-18 ◽  
Author(s):  
B. Tebbe ◽  
J. Mankertz ◽  
C. Schwarz ◽  
S. Amasheh ◽  
M. Fromm ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Tight Junction ◽  
Integral Membrane Proteins ◽  
Tight Junction Proteins ◽  
Junction Proteins

Freeze-fracture replica electron microscopy combined with SDS digestion for cytochemical labeling of integral membrane proteins. Application to the immunogold labeling of intercellular junctional complexes

1995 ◽  
Vol 108 (11) ◽  
pp. 3443-3449 ◽  
Author(s):  
K. Fujimoto
Keyword(s):  
Membrane Proteins ◽  
Tight Junction ◽  
Plasma Membranes ◽  
Freeze Fracture ◽  
Immunogold Labeling ◽  
Integral Membrane Proteins ◽  
Tissue Slices ◽  
Electron Microscopic ◽  
Junction Protein ◽  
Junction Proteins

We propose a new electron microscopic method, the sodium dodecylsulphate (SDS)-digested freeze-fracture replica labeling technique, to study the two-dimensional distribution of integral membrane proteins in cellular membranes. Unfixed tissue slices were frozen with liquid helium, freeze-fractured, and replicated in a platinum/carbon evaporator. They were digested with 2.5% SDS to solubilize unfractured membranes and cytoplasm. While the detergent dissolved unfractured membranes and cytoplasm, it did not extract fractured membrane halves. After SDS-digestion, the platinum/carbon replicas, along with attached cytoplasmic and exoplasmic membrane halves, were processed for cytochemical labeling, followed by electron microscopic observation. As an initial screening, we applied this technique to the immunogold labeling of intercellular junction proteins: connexins (gap junction proteins), occludin (tight junction protein), desmoglein (desmosome protein), and E-cadherin (adherens junction protein). The immunogold labeling was seen superimposed on the image of a fracture face visualized by platinum/carbon shadowing. The immunoreaction was specific, and only the structures where the proteins were expected were labeled. For instance, anti-occludin immunogold complexes were observed immediately adjacent to the tight junction strands on the protoplasmic and exoplasmic fracture faces. No significant levels of gold label were associated with non-tight-junctional regions of plasma membranes. The procedures of the SDS-digested freeze-fracture replica labeling and its potential significance are discussed.

Tight junction proteins in HCC and metastatic liver tumours

2005 ◽  
Vol 43 (05) ◽  
Author(s):  
Cs Páska ◽  
E Orbán ◽  
A Kiss ◽  
Zs Schaff ◽  
A Szijjártó ◽  
...  
Keyword(s):  
Tight Junction ◽  
Tight Junction Proteins ◽  
Liver Tumours ◽  
Metastatic Liver ◽  
Junction Proteins

Evidence that gene expression of ovarian follicular tight junction proteins is regulated in vivo and in vitro in cattle

2017 ◽  
Vol 95 (3) ◽  
pp. 1313 ◽  
Author(s):  
L. Zhang ◽  
L. F. Schütz ◽  
C. L. Robinson ◽  
M. L. Totty ◽  
L. J. Spicer
Keyword(s):  
Gene Expression ◽  
Tight Junction ◽  
Tight Junction Proteins ◽  
Junction Proteins

New insights in gut-liver axis in wild-type murine imiquimod-induced lupus

Lupus ◽  
2021 ◽  
Vol 30 (6) ◽  
pp. 926-936
Author(s):  
Georges Maalouly ◽  
Joelle Hajal ◽  
Charbel Noujeim ◽  
Michel Choueiry ◽  
Hussein Nassereddine ◽  
...  
Keyword(s):  
Tight Junction ◽  
Fecal Calprotectin ◽  
Liver Inflammation ◽  
Tight Junction Proteins ◽  
Wild Type ◽  
Imiquimod Cream ◽  
E Coli ◽  
Intestinal Pathology ◽  
Nfκb Pathway ◽  
Junction Proteins

Background Intestinal and hepatic manifestations of lupus seem to be underestimated in comparison to other major organ lesions. Although recent data point to gut-liver axis involvement in lupus, gut permeability dysfunction and liver inflammation need to be more investigated. Objective This study aims to assess fecal calprotectin, intestinal tight junction proteins and liver inflammation pathway in wild-type murine imiquimod- induced lupus. Methods C57BL/6 mice were topically treated on their right ears with 1.25 mg of 5% imiquimod cream, three times per week for six weeks. Fecal calprotectin was collected at day 0, 22 and 45. Renal, liver and intestinal pathology, as well as inflammatory markers, intestinal tight junction proteins, and E. coli protein in liver were assessed at sacrifice. Results At six weeks, lupus nephritis was confirmed on histopathology and NGAL and KIM-1 expression. Calprotectin rise started at day 22 and persists at day 45. Protein expression of Claudine, ZO-1 and occludin was significantly decreased. E. coli protein was significantly increased in liver with necro-inflammation and increased TLR4, TLR7, and pNFκB/NFκB liver expression. Conclusion This study is the first to demonstrate early fecal calprotectin increase and liver activation of TLR4- NFκB pathway in wild-type murine imiquimod-induced lupus.

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