Editorial
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. Feb 18, 2016; 7(2): 74-77
Published online Feb 18, 2016. doi: 10.5312/wjo.v7.i2.74
Bone and high-density lipoprotein: The beginning of a beautiful friendship
Dionysios J Papachristou, Harry C Blair
Dionysios J Papachristou, Department of Anatomy-Histology-Embryology, Unit of Bone and Soft Tissue Studies, University of Patras, School of Medicine, 26504 Rion-Patras, Greece
Dionysios J Papachristou, Harry C Blair, Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15261, United States
Harry C Blair, Pittsburgh VA Medical Center, Pittsburgh, PA 15261, United States
Author contributions: Papachristou DJ conceived the general idea of the paper; Papachristou DJ and Blair HC wrote the paper.
Conflict-of-interest statement: The authors declare no conflict of interest.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Dionysios J Papachristou, MD, PhD, Consultant Histopathologist, Associate Professor, Department of Anatomy-Histology-Embryology, Unit of Bone and Soft Tissue Studies, University of Patras, School of Medicine, University Campus, Building of Preclinical Studies, 2nd Floor, Room B48, 26504 Rion-Patras, Greece. papachristoudj@med.upatras.gr
Telephone: +30-2610-969188 Fax: +30-2610-969178
Received: July 5, 2015
Peer-review started: July 13, 2015
First decision: September 22, 2015
Revised: November 7, 2015
Accepted: December 1, 2015
Article in press: December 2, 2015
Published online: February 18, 2016
Processing time: 225 Days and 17.3 Hours
Abstract

There is a tight link between bone and lipid metabolic pathways. In this vein, several studies focused on the exploration of high-density lipoprotein (HDL) in the pathobiology of bone diseases, with emphasis to the osteoarthritis (OA) and osteoporosis, the most common bone pathologies. Indeed, epidemiological and in vitro data have connected reduced HDL levels or dysfunctional HDL with cartilage destruction and OA development. Recent studies uncovered functional links between HDL and OA fueling the interesting hypothesis that OA could be a chronic element of the metabolic syndrome. Other studies have linked HDL to bone mineral density. Even though at epidemiological levels the results are conflicting, studies in animals as well as in vitro experiments have shown that HDL facilitates osteoblastogensis and bone synthesis and most probably affects osteoclastogenesis and osteoclast bone resorption. Notably, reduced HDL levels result in increased bone marrow adiposity affecting bone cells function. Unveiling the mechanisms that connect HDL and bone/cartilage homeostasis may contribute to the design of novel therapeutic agents for the improvement of bone and cartilage quality and thus for the treatment of related pathological conditions.

Keywords: High-density lipoprotein; Cartilage; Bone; Osteoarthritis; Osteoporosis

Core tip: Recent evidence suggests that high-density lipoprotein (HDL) metabolic pathways are closely related to bone and cartilage homeostasis. In this editorial the authors briefly present the current knowledge concerning the mechanisms that link HDL and cartilage and bone metabolism and discuss the role of HDL result in the development of the most common bone pathological conditions, osteoarthritis and osteoporosis. These data add to the appreciation of bone and lipid connection and pave the way towards the development of novel HDL-related strategies for the treatment of these diseases.