Leptin receptor is up-regulated in inflamed human dental pulp.
BACKGROUND
After leptin receptor (LEPR) identification in hematopoietic, immune system, and other tissues, a role for leptin regulating inflammation and immune response has been accepted. This study aims to describe the possible expression of LEPR in healthy human dental pulp and to compare it with LEPR expression in inflamed human dental pulp.


METHODS
Twenty-one pulp samples were obtained from freshly extracted caries-free and restoration-free human third molars. In 7 third molars (inflamed pulp group), inflammation was experimentally induced before extraction. Pulp samples were processed, and LEPR expression was determined by quantitative real-time polymerase chain reaction, and the amount of LEPR protein was analyzed by immunoblot.


RESULTS
All healthy and inflamed dental pulp samples expressed LEPR. Western blot analysis of human dental pulp revealed the presence of a protein with an apparent molecular weight of approximately 120 kDa, which corresponds to the estimated molecular weight of LEPR. The expression of LEPR mRNA was confirmed by quantitative real-time polymerase chain reaction analysis, and the size of the amplified fragment (338 base pairs for LEPR and 194 base pairs for cyclophilin) was assessed by agarose gel electrophoresis. The relative amount of LEPR in inflamed pulps was approximately 50% higher than in healthy pulps (P < .05).


CONCLUSIONS
The presence of LEPR in human dental pulp tissues has been demonstrated for the first time. The up-regulation of LEPR expression in inflamed pulp samples suggests that leptin can play a role in inflammatory and local immune responses in human dental pulp.
Department of Stomatology (Endodontics section), School of Dentistry, University of Sevilla, Sevilla, Spain.
Jénifer
J
Martín-González
Antonio
A
Pérez-Pérez
Flora
F
Sánchez-Jiménez
Antonio
A
Carmona-Fernández
Daniel
D
Torres-Lagares
Víctor
V
Sánchez-Margalet
Juan J
JJ
Segura-Egea
D000328:Adult; D015153:Blotting, Western; D003782:Dental Pulp / Q000276:immunology / Q000378:metabolism; D003789:Dental Pulp Exposure / Q000378:metabolism; D004587:Electrophoresis, Agar Gel; D006801:Humans; D011671:Pulpitis / Q000276:immunology / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D060888:Real-Time Polymerase Chain Reaction; D054411:Receptors, Leptin / Q000032:analysis / Q000378:metabolism*; D015854:Up-Regulation; D055815:Young Adult
D012333:RNA, Messenger; D054411:Receptors, Leptin
Dental pulp stem cells; leptin; pulp immune response; pulp inflammatory response; pulp neuropeptides