Effect of recombinant human endostatin on the intracellular Ca²⁺ concentration in hypertrophic scar fibroblasts in a rabbit ear model

ObjectiveTo investigate the mechanism of recombinant human endostatin(rhEndostatin) promoting the apoptosis of hypertrophic scar fibroblast(HSFs) in rabbit ear, and provide the experimental basis for clinical drug treatment of hypertrophic scar(HS).

MethodsThe HS model was prepared in 6 healthy New Zealand white albino rabbits.The effects of rhEndostatin(100 μg/mL) on the intracellular Ca²⁺ concentration(Ca²⁺ i) of HSFs in Hanks and D-Hanks fluids(with and without extracellular calcium) were detected using laser confocal microscopy(CLSM) combined with Fluo-4 /AM(Ca²⁺ fluorescence indicator).

ResultsWhen the extracellular fluid was the Hanks fluid, the rhEndostatin could cause the HSFs Ca²⁺i increasing, and the levels of Ca²⁺i reached to peak after 10 s of treatment, then slowly decreased with time.After stopping the drug treatment, the levels of Ca²⁺i continued to slow down, and the level of HSFs Ca²⁺i did not return to baseline after 50 s of rhEndostatin withdrawal.HSFs Ca²⁺i was not affected by rhEndostatin when the cells were incubated with D-Hanks buffer.

ConclusionsRhEndostatin can induce the HSFs apoptosis by interfering with intracellular Ca²⁺ homeostasis and promoting extracellular Ca²⁺ influx to cause intracellular calcium overload.