Effects of Combination of 1,25(OH) 2D 3 and TLR-4 Inhibitor on the Damage to HaCaT Cells Caused by UVB Irradiation.

OBJECTIVE

Vitamin D and Toll-like receptor-4 (TLR-4) inhibition are involved in the protection of keratinocytes. The effects of combination of 1,25(OH) 2D 3 and TLR-4 inhibitor on the protection of keratinocytes against ultraviolet radiation B (UVB) irradiation remain unclear. This study was undertaken to explore the effects of combination of 1,25(OH) 2D 3 and TAK-242 (TLR-4 inhibitor) on the damage to HaCaT cells caused by UVB irradiation.

METHODS

In vitro, HaCaT cells were treated with 1,25(OH) 2D 3 or/and TAK-242 prior to UVB irradiation at the intensity of 20 mJ/cm 2, then the production of reactive oxygen species (ROS), cell migration, apoptosis of cells, and the expression of oxidative stress, endoplasmic reticulum stress, and apoptosis related proteins were determined.

RESULTS

Compared with the HaCaT cells treated with 1,25(OH) 2D 3 or TAK-242, the cells treated with both 1,25(OH) 2D 3 and TAK-242 showed, 1) significantly lower production of ROS ( P < 0.05); 2) significantly less apoptosis of HaCaT cells ( P < 0.05); 3) significantly lower expression of NF- κB, Caspase-8, Cyto-C, Caspase-3 ( P < 0.05).

CONCLUSION

The combination of 1,25(OH) 2D 3 and TAK-242 could produce a better protection for HaCaT cells via inhibiting the oxidative stress, endoplasmic reticulum stress and apoptosis than 1,25(OH) 2D 3 or TAK-242 alone.