Cell surface energy, contact angles and phase partition. I. Lymphocytic cell lines in biphasic aqueous mixtures

SummaryWe previously reported that extracellular matrix invasion by the prostate cancer cell lines, PC-3 and DU-145 was contingent on endogenous urokinase being bound to a specific cell surface receptor. The present study was undertaken to characterize the expression of both urokinase and its receptor in the non-invasive LNCaP and the invasive PC-3 and DU-145 prostate cells. Northern blotting indicated that the invasive PC-3 cells, which secreted 10 times more urokinase (680 ng/ml per 106 cells per 48 h) than DU-145 cells (63 ng/ml per 106 cells per 48 h), had the most abundant transcript for the plasminogen activator. This, at least, partly reflected a 3 fold amplification of the urokinase gene in the PC-3 cells. In contrast, urokinase-specific transcript could not be detected in the non-invasive LNCaP cells previously characterized as being negative for urokinase protein. Southern blotting indicated that this was not a consequence of deletion of the urokinase gene. Crosslinking of radiolabelled aminoterminal fragment of urokinase to the cell surface indicated the presence of a 51 kDa receptor in extracts of the invasive PC-3 and DU-145 cells but not in extracts of the non-invasive LNCaP cells. The amount of binding protein correlated well with binding capacities calculated by Scatchard analysis. In contrast, the steady state level of urokinase receptor transcript was a poor predictor of receptor display. PC-3 cells, which were equipped with 25,000 receptors per cell had 2.5 fold more steady state transcript than DU-145 cells which displayed 93,000 binding sites per cell.

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Faculty Opinions recommendation of Assembly and cell surface expression of TAP-independent, chloroquine-sensitive and interferon-gamma-inducible class I MHC complexes in transformed fibroblast cell lines are regulated by tapasin.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1009214.121258 ◽

2002 ◽

Author(s):

Tim Elliott

Keyword(s):

Cell Surface ◽

Cell Lines ◽

Interferon Gamma ◽

Fibroblast Cell ◽

Surface Expression ◽

Class I ◽

Cell Surface Expression ◽

Class I Mhc ◽

Fibroblast Cell Lines

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Study on contact angles and surface energy of MXene films

RSC Advances ◽

10.1039/d0ra09125a ◽

2021 ◽

Vol 11 (10) ◽

pp. 5512-5520

Author(s):

Hang Zhou ◽

Fuqiang Wang ◽

Yuwei Wang ◽

Changping Li ◽

Changrui Shi ◽

...

Keyword(s):

Surface Energy ◽

Contact Angles ◽

Time Dependent ◽

Wetting Behaviors

This work sheds light on the process- and time-dependent wetting behaviors and surface energy of MXene films.

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Trace Amine-Associated Receptor 1 Trafficking to Cilia of Thyroid Epithelial Cells

Cells ◽

10.3390/cells10061518 ◽

2021 ◽

Vol 10 (6) ◽

pp. 1518

Author(s):

Maria Qatato ◽

Vaishnavi Venugopalan ◽

Alaa Al-Hashimi ◽

Maren Rehders ◽

Aaron D. Valentine ◽

...

Keyword(s):

Cell Surface ◽

Cell Lines ◽

Human Thyroid ◽

Apical Plasma Membrane ◽

Thyroid Cell ◽

Thyroid Cells ◽

Trace Amine ◽

Rat Thyroid

Trace amine-associated receptor 1 (rodent Taar1/human TAAR1) is a G protein-coupled receptor that is mainly recognized for its functions in neuromodulation. Previous in vitro studies suggested that Taar1 may signal from intracellular compartments. However, we have shown Taar1 to localize apically and on ciliary extensions in rodent thyrocytes, suggesting that at least in the thyroid, Taar1 may signal from the cilia at the apical plasma membrane domain of thyrocytes in situ, where it is exposed to the content of the follicle lumen containing putative Taar1 ligands. This study was designed to explore mouse Taar1 (mTaar1) trafficking, heterologously expressed in human and rat thyroid cell lines in order to establish an in vitro system in which Taar1 signaling from the cell surface can be studied in future. The results showed that chimeric mTaar1-EGFP traffics to the apical cell surface and localizes particularly to spherical structures of polarized thyroid cells, procilia, and primary cilia upon serum-starvation. Moreover, mTaar1-EGFP appears to form high molecular mass forms, possibly homodimers and tetramers, in stably expressing human thyroid cell lines. However, only monomeric mTaar1-EGFP was cell surface biotinylated in polarized human thyrocytes. In polarized rat thyrocytes, mTaar1-EGFP is retained in the endoplasmic reticulum, while cilia were reached by mTaar1-EGFP transiently co-expressed in combination with an HA-tagged construct of the related mTaar5. We conclude that Taar1 trafficking to cilia depends on their integrity. The results further suggest that an in vitro cell model was established that recapitulates Taar1 trafficking in thyrocytes in situ, in principle, and will enable studying Taar1 signaling in future, thus extending our general understanding of its potential significance for thyroid autoregulation.

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