DOI: 10.5061/dryad.q2bvq83n6
title: Senescent preosteoclast secretome promotes metabolic syndrome-associated osteoarthritis through COX2-PGE2

description: Metabolic syndrome–associated osteoarthritis (MetS-OA) is a distinct
 osteoarthritis phenotype defined by the coexistence of MetS or its
 individual components. Despite the high prevalence of MetS-OA, its
 pathogenic mechanisms are unclear. Here, we report that humans and mice
 with MetS are more likely to develop osteoarthritis-related subchondral
 bone alterations than those without MetS. MetS-OA mice exhibited a rapid
 increase in joint subchondral bone plate and trabecular thickness before
 articular cartilage degeneration. Subchondral preosteoclasts undergo
 senescence at the pre- or early-osteoarthritis stage and acquire a unique
 secretome to stimulate osteoblast differentiation and inhibit osteoclast
 differentiation. Antagonizing preosteoclast senescence markedly mitigates
 pathological subchondral alterations and osteoarthritis progression in
 MetS-OA mice. At the molecular level, preosteoclast secretome activates
 COX2-PGE2, resulting in stimulated differentiation of osteoblast
 progenitors for subchondral bone formation. Administration of a selective
 COX2 inhibitor attenuated subchondral bone alteration and osteoarthritis
 progression in MetS-OA mice. Longitudinal analyses of the human
 Osteoarthritis Initiative (OAI) cohort dataset also revealed that COX2
 inhibitor use, relative to non-selective nonsteroidal anti-inflammatory
 drug use, is associated with less progression of osteoarthritis and
 subchondral bone marrow lesion worsening in participants with MetS-OA. Our
 findings suggest a central role of a senescent preosteoclast
 secretome-COX2/PGE2 axis in the pathogenesis of MetS-OA.
description: Preosteoclasts were challenged with H2O2 (200 µM for
 2 hours, then 20 µmol for 1 day) or vehicle (control). The group has 3
 samples. We completed the analysis of the Agilgent gene expression
 profiling chip of the samples. RNA quantity and quality were assessed
 using NanoDrop ND-1000. RNA integrity was assessed by standard denaturing
 gel electrophoresis. Sequences were collected from a wide range of
 sources, then validated and optimized by alignment to the assembled mouse
 genome. Sample labeling and chip hybridization were performed according to
 the Agilent One-Color Microarray-Based Gene Expression Analysis protocol
 (Agilent Technology) with minor modifications. Total RNA from each sample
 was linearly amplified and labeled with Cy3-UTP. Labeled cRNAs were
 purified using the RNeasy Mini Kit (Qiagen) and assayed for concentration
 and activity with a NanoDrop ND-1000. Chip hybridization. The
 hybridization chip was washed, mounted and scanned (Agilent DNA Microarray
 Scanner (part number G2505C)). Use the Agilent Feature Extraction software
 (v11.0.1.1) to obtain the chip map, and read the value to obtain the raw
 data. Raw data were subjected to Quantile normalization and subsequent
 data processing using GeneSpring GX v12.1 software (Agilent Technologies).
 After standardization of the raw data, high-quality probes (a probe based
 on the proportion of qualified markers Detected) are screened for further
 analysis.