VB124

Cell lines

MDA-MB-231

Preparation Method

MCT4 and MCT1 lactate transport assays that use the pH-sensitive fluorescent dye 2′−7′-bis(carboxyethyl)-5(6)-carboxyfluorescein (BCECF) to detect changes in intracellular pH (pHi) accompanying MCT-mediated lactate/proton symport, were developed in a manner similar to that reported previously.To measure lactate import, 2.5μL BCECF-loaded cells, along with either 10μL DMSO or 100x compound in DMSO, were added to 937.5μL of Tyrode’s Solution in a quartz 1.0mL cuvette. Fluorescence measurements are performed on a PerkinElmer LS55 fluorescence spectrometer with dual excitation wavelengths achieved using a filter wheel. After establishing baseline BCECF fluorescence (around 10–20s), 50μL of M sodium L-lactate was added to the cuvette (final concentration: 50mM) and rapidly mixed. The time-dependent decrease in BCECF fluorescence (490/440 ratio) was fit to an exponential decay curve to determine the rate of lactate transport. Lactate export was measured similarly to import.

Reaction Conditions

MCT4-mediated import:0-3.3μM; MCT4-mediated export:0-10μM;

Applications

VB124 treatment reduces intracellular reactive oxygen species (ROS) levels and decreases cardiomyocyte death.

Animal models

C57BL/6J

Preparation Method

To test this, we replicated our I/R protocol administering either a single dose of placebo or VB124 (30 mg/kg) via oral gavage prior to performing I/R. Unlike in the acute model, the mice were permitted to recover after surgery, and we performed serial echocardiography over a 3-week period to assess cardiac structure and function .

Dosage form

30mg/kg; i.g;

Applications

VB124 inhibits MCT4, resulting in a decrease in intracellular lactate and pyruvate levels, further exacerbating hypoxic injury caused by acute cardiac ischemia-reperfusion (I/R) in mice.

References:
[1]Cluntun AA, Badolia R, Lettlova S, Parnell KM, Shankar TS, Diakos NA, Olson KA, Taleb I, Tatum SM, Berg JA, Cunningham CN, Van Ry T, Bott AJ, Krokidi AT, Fogarty S, Skedros S, Swiatek WI, Yu X, Luo B, Merx S, Navankasattusas S, Cox JE, Ducker GS, Holland WL, McKellar SH, Rutter J, Drakos SG. The pyruvate-lactate axis modulates cardiac hypertrophy and heart failure. Cell Metab. 2021 Mar 2;33(3):629-648.e10.
[2]Visker JR, Cluntun AA, Velasco-Silva JN, Eberhardt DR, Cedeño-Rosario L, Shankar TS, Hamouche R, Ling J, Kwak H, Hillas JY, Aist I, Tseliou E, Navankasattusas S, Chaudhuri D, Ducker GS, Drakos SG, Rutter J. Enhancing mitochondrial pyruvate metabolism ameliorates ischemic reperfusion injury in the heart. JCI Insight. 2024 Jul 25;9(17):e180906.