Topical prostaglandin analogue drugs inhibit adipocyte differentiation

Abstract

Purpose: To investigate the effects of topical prostaglandin analogue drugs on the differentiation of adipocytes.

Methods: Differentiation of 3T3-L1 preadipocytes was induced with isobutylmethylxanthine, dexamethasone, and insulin. 3T3-L1 cells were exposed to 0.008, 0.08, 0.2 µM of latanoprost and travoprost. Reverse transcription polymerase chain reaction for mRNA expression of lipoprotein lipase and peroxisome proliferator-activated receptor γ 2 (PPARγ2), and glycerol-3-phosphate dehydrogenase (G3PDH) assays were performed to examine the effects on early and late differentiation, respectively. Also, glycerol assays were done to evaluate the effect of prostaglandin analogues on lipolysis after differentiation.

Results: Both prostaglandin analogues inhibited differentiation of preadipocytes. Topical prostaglandin analogues significantly decreased G3PDH activity, a marker of late differentiation. However, topical prostaglandin analogues did not change mRNA expressions of lipoprotein lipase and PPARγ2, markers of early differentiation. The activities of the early markers of differentiation were not changed significantly before and after growth arrest. Compared to latanoprost, travoprost decreased G3PDH activity more significantly (p < 0.05). Both prostaglandin analogues did not affect the lipolysis of differentiated adipocytes (p > 0.05).

Conclusions: Prostaglandin analogues display an inhibitory effect on the differentiation of adipocytes when the cells start to differentiate especially in the late stage of differentiation. Thus, commercial topical prostaglandin analogues may decrease the fat contents of eyelids.

Keywords: Adipocytes; Differentiation; Eyelids; Prostaglandin.

Fig. 1

Photomicrograph of 3T3-L1 cells cultivated in the presence (A) or absence of MDI (methylisobutylxanthine, dexamethasone, insulin) cocktail (B). Differentiation was initiated by treating the cells for 48 hours with 1 mg/mL dexamethasone, 0.5 mM isobutylmethylxanthine, and 10 mg/mL insulin (×100).

Fig. 2

Effect of topical prostaglandin (PG) analogues on the activity of mRNA expression of lipoprotein lipase (A) and peroxisome proliferator-activated receptor γ 2 (PPARγ2, early differentiation markers) (B) in 3T3-L1 preadipocytes. 3T3-L1 cells were cultivated in defined medium alone (control, C) or in the presence of 0.2, 0.08, 0.008 µM latanoprost (L) or 0.2, 0.08, 0.008 µM travoprost (T). Topical PGs did not increase the expression of mRNA of lipoprotein lipase or PPARγ2.

Fig. 3

Effect of topical prostaglandin (PG) analogues on the expression of mRNA of lipoprotein lipase in 3T3-L1 preadipocytes before and after growth arrest. Neither PG analogue significantly changed the activity of lipoprotein lipase before and after growth arrest (p > 0.05).

Fig. 4

Effect of topical prostaglandin (PG) analogues on the expression of mRNA of peroxisome proliferator-activated receptor γ 2 (PPARγ2) in 3T3-L1 preadipocytes before and after growth arrest. Neither PG analogue significantly changed the activity of PPARγ2 before and after growth arrest (p > 0.05).

Fig. 5

Effects of topical prostaglandin (PG) analogues on the activity of glycerol-3-phosphate dehydrogenase (G3PDH, late differentiation marker) in 3T3-L1 preadipocytes. 3T3-L1 cells were cultivated in defined medium, as described in Materials and Methods section. PG analogues were added when differentiation started on day 4, and their application was maintained throughout the experiment. Cells were harvested on day 10 to measure G3PDH specific activity (%). Both latanoprost and travoprost decreased G3PDH activity significantly in a dose-dependent manner compared to the non-exposed control (^*p < 0.05). Travoprost decreased G3PDH activities more than latanoprost at each concentration (^**p < 0.05).

Fig. 6

Effects of topical prostaglandin (PG) analogues on the stimulation of 3T3-L1 cell lipolysis with glycerol assay. 3T3-L1 cells were cultivated in defined medium, as described in Materials and Methods section. PG analogues were added after differentiation and maintained throughout the experiment. Cells were harvested on day 14 to measure glycerol (µg/mL). Addition of latanoprost or travoprost to the differentiated adipocytes did not increase glycerol accumulation in the medium compared to the non-exposed control (p > 0.05).