Coptisine/Berberine Regulate The Expression Of UCP1 Via Modifying The Conformation Of G-quadruplex Formed By Its Oligonucleotide Fragment In The Promoter

Obesity and its metabolic diseases are currently a global public health problem,but there is still a lack of safe and effective prevention and treatment methods.Mitochondrial uncoupling protein 1(UCP1)has become a new target for obesity prevention and treatment due to its important role in energy metabolism,energy balance and white fat browning.Gene sequence analysis confirmed that the promoter region of UCP1 gene was rich in guanine G,which could form a G-quadruplex structure,which might affect the activity and expression of UCP1 gene promoter.First,the interaction between coptisine/berberine and the G-quadruplex formed by UCP1 gene oligo fragment was studied.UV scanning,fluorescence spectroscopy,circular dichroism,molecular docking and non-denaturing polyacrylamide gel electrophoresis confirmed that coptisine/berberine interacts with G-quadruplex formed by UCP1 gene oligo fragment,which can promote the transformation of its configuration from intramolecular Gquadruplex to intermolecular G-quadruplex.then,the effect of coptisine/berberine on the activity of UCP1 promoter was investigated by double luciferase reporter gene assay.The results showed that coptisine/berberine can directly affect the activity of UCP1 promoter.At the same time,q RTPCR and Western blot experiments showed that coptisine/berberine can up regulate the expression of UCP1 in differentiated 3T3-L1 adipocytes in a time-dependent and dosedependent manner.In addition,oil red staining showed that coptisine/berberine can inhibit the accumulation of lipid droplets in differentiated 3T3-L1 adipocytes;Immunofluorescence results showed that coptisine/berberine can induce UCP1 expression and significantly increase the quantity of mitochondria in differentiated 3T3-L1 adipocytes.All these findings reveal that coptisine/berberine can affect the activity of UCP1 promoter and regulate UCP1 expression by changing the configuration of G-quadruplex formed by UCP1 gene oligo fragment.Additionally,both coptisine/berberine attenuated the accumulation of lipid droplets and increased the quantity of mitochondria in differentiated3T3-L1 adipocytes,suggested that coptisine/berberine hold the potential to induce browning of white fat,and are beneficial to the prevention and treatment of obesity.