scholarly journals Litmus-Body: A Molecularly Targeted Sensor for Cell-Surface pH Measurements

ACS Sensors ◽  
2020 ◽  
Vol 5 (6) ◽  
pp. 1555-1566 ◽  
Author(s):  
Joe Chin-Hun Kuo ◽  
Marc C. Goudge ◽  
Ann E. Metzloff ◽  
Ling-Ting Huang ◽  
Marshall J. Colville ◽  
...  
Keyword(s):  
Cell Surface ◽  
Ph Measurements ◽  
Surface Ph

scholarly journals Probe for the measurement of cell surface pH in vivo and ex vivo

2016 ◽  
Vol 113 (29) ◽  
pp. 8177-8181 ◽  
Author(s):  
Michael Anderson ◽  
Anna Moshnikova ◽  
Donald M. Engelman ◽  
Yana K. Reshetnyak ◽  
Oleg A. Andreev
Keyword(s):  
Cell Surface ◽  
Tumor Cell ◽  
Cancer Cells ◽  
Metastatic Cancer ◽  
Surface Acidity ◽  
Measurement Tool ◽  
Mouse Tumor ◽  
Cell Surfaces ◽  
Surface Ph

We have developed a way to measure cell surface pH by positioning a pH-sensitive fluorescent dye, seminaphtharhodafluor (SNARF), conjugated to the pH low insertion peptide (pHLIP). It has been observed that many diseased tissues are acidic and that tumors are especially so. A combination of effects acidifies tumor cell interiors, and cells pump out lactic acid and protons to maintain intracellular pH, acidifying the extracellular space. Overexpression of carbonic anhydrases on cell surfaces further contributes to acidification. Thus, the pH near tumor cell surfaces is expected to be low and to increase with distance from the membrane, so bulk pH measurements will not report surface acidity. Our new surface pH-measurement tool was validated in cancer cells grown in spheroids, in mouse tumor models in vivo, and in excised tumors. We found that the surface pH is sensitive to cell glycolytic activity: the pH decreases in high glucose and increases if glucose is replaced with nonmetabolized deoxyglucose. For highly metastatic cancer cells, the pH measured at the surface was 6.7–6.8, when the surrounding external pH was 7.4. The approach is sensitive enough to detect 0.2–0.3 pH unit changes in vivo in tumors induced by i.p. injection of glucose. The pH at the surfaces of highly metastatic cells within tumors was found to be about 6.1–6.4, whereas in nonmetastatic tumors, it was 6.7–6.9, possibly creating a way to distinguish more aggressive from less aggressive tumors. Other biological roles of surface acidity may be found, now that targeted measurements are possible.

Response of cell surface pH to pCO2 and iron limitation in the marine diatom Thalassiosira weissflogii

2009 ◽  
Vol 114 (1-2) ◽  
pp. 31-36 ◽  
Author(s):  
Allen J. Milligan ◽  
Cécile E. Mioni ◽  
François M.M. Morel
Keyword(s):  
Cell Surface ◽  
Iron Limitation ◽  
Marine Diatom ◽  
Thalassiosira Weissflogii ◽  
Surface Ph

The Design of a Monitoring Program for Iron Alloys on Underwater Historic Shipwrecks in Fathom Five National Marine Park, Ontario, Canada

1996 ◽  
Vol 462 ◽  
Author(s):  
John Stewart ◽  
Lome D. Murdock ◽  
Nancy Binnie
Keyword(s):  
Monitoring Program ◽  
Iron Alloys ◽  
Visual Observation ◽  
Photographic Recording ◽  
Ph Measurements ◽  
Surface Ph ◽  
X Ray ◽  
Marine Park ◽  
Predominant Form

ABSTRACTIn order to design a scheme to monitor the state of preservation of iron alloys that are found on historic shipwrecks sunk in fresh water, it was first necessary to identify the predominant form of corrosion found on the wrecks. This was done by visual observation, in situ surface pH measurements, and X-ray powder diffraction of the corrosion layers. Once the form of corrosion was identified as pitting corrosion, a monitoring scheme based on photographic recording of the rust-red tubercles was designed. This scheme is simple and nondestructive, both necessary characteristics for the monitoring of submerged historic resources.

Evolutionary determinants of normal arterial plasma pH in ectothermic vertebrates

2002 ◽  
Vol 205 (5) ◽  
pp. 641-650
Author(s):  
Richard F. Burton
Keyword(s):  
Cell Surface ◽  
Interstitial Fluid ◽  
Acid Base ◽  
Arterial Pco2 ◽  
Surface Ph ◽  
Mean Values ◽  
Surface Sites ◽  
Arterial Ph ◽  
Arterial Plasma ◽  
Optimal Ph

SUMMARYMean values of normal arterial pH in different species of fish, amphibians and reptiles at 15 and 25°C, taken from the literature, are negatively correlated with arterial PCO2 and plasma [Na+]. At either temperature, the data accord with the hypothesis that extracellular acid–base homeostasis evolved to maintain an optimal pH at particular cell-surface sites that are similar in all species. These hypothetical sites bear fixed negative charges that attract H+, but which are partially screened by Na+; for the surface pH to be constant, the bulk interstitial pH should then vary inversely with [Na+], as is the case. At the same time, the bulk interstitial fluid must be more acid than arterial plasma by an amount that increases with decreasing arterial PCO2. With allowance made for additional screening by Ca2+ and Mg2+, the relevant cell-surface pH is probably approximately 6.2.

The clinical application of surface pH measurements to longitudinally assess white spot enamel lesions

2010 ◽  
Vol 38 (7) ◽  
pp. 584-590 ◽  
Author(s):  
Yuichi Kitasako ◽  
Nathan J. Cochrane ◽  
Matin Khairul ◽  
Kanako Shida ◽  
Geoffrey G. Adams ◽  
...  
Keyword(s):  
Clinical Application ◽  
White Spot ◽  
Ph Measurements ◽  
Surface Ph
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