Trehalose ameliorates oxidative stress-mediated mitochondrial dysfunction and ER stress via selective autophagy stimulation and autophagic flux restoration in osteoarthritis development

Abstract

Oxidative stress-related apoptosis and autophagy play crucial roles in the development of osteoarthritis (OA), a progressive cartilage degenerative disease with multifactorial etiologies. Here, we determined autophagic flux changes and apoptosis in human OA and tert-Butyl hydroperoxide (TBHP)-treated chondrocytes. In addition, we explored the potential protective effects of trehalose, a novel Mammalian Target of Rapamycin (mTOR)-independent autophagic inducer, in TBHP-treated mouse chondrocytes and a destabilized medial meniscus (DMM) mouse OA model. We found aberrant p62 accumulation and increased apoptosis in human OA cartilage and chondrocytes. Consistently, p62 and cleaved caspase-3 levels increased in mouse chondrocytes under oxidative stress. Furthermore, trehalose restored oxidative stress-induced autophagic flux disruption and targeted autophagy selectively by activating BCL2 interacting protein 3 (BNIP3) and Phosphoglycerate mutase family member 5 (PGAM5). Trehalose could ameliorate oxidative stress-mediated mitochondrial membrane potential collapse, ATP level decrease, dynamin-related protein 1 (drp-1) translocation into the mitochondria, and the upregulation of proteins involved in mitochondria and endoplasmic reticulum (ER) stress-related apoptosis pathway. In addition, trehalose suppressed the cleavage of caspase 3 and poly(ADP-ribose) polymerase (PARP) and prevented DNA damage under oxidative stress. However, the anti-apoptotic effects of trehalose in TBHP-treated chondrocytes were partially abolished by autophagic flux inhibitor chloroquine and BNIP3- siRNA. The protective effect of trehalose was also found in mouse OA model. Taken together, these results indicate that trehalose has anti-apoptotic effects through the suppression of oxidative stress-induced mitochondrial injury and ER stress which is dependent on the promotion of autophagic flux and the induction of selective autophagy. Thus, trehalose is a promising therapeutic agent for OA.

TFEB protects nucleus pulposus cells against apoptosis and senescence via restoring autophagic flux

“…To our knowledge, the expression alteration of p62 (a protein representing the degradation level of autophagic vacuoles) and lysosome activity in the process of IVDD is still unknown. Our group latterly reported that high accumulation of p62 appears in human OA cartilage and destabilized medial meniscus (DMM) mouse OA model, suggesting that autophagic degradation is blocked in OA chondrocytes 39 . Moreover, Kim et al observed accumulation of lysosomes and decline of lysosomal activity in human OA chondrocytes relative to normal chondrocytes, also they showed that destroying lysosome results in enhanced chondrocyte apoptosis and inhibition of autophagy 40 .…”

Melatonin protects vertebral endplate chondrocytes against apoptosis and calcification via the Sirt1‐autophagy pathway

“…For immunofluorescence, as a previous study described, EPCs were plated in six‐well glass plates, and then, after incubating with serum‐starved medium overnight, the cells were treated with 50 μM TBHP or were co‐treated with 50 μM TBHP and 1 μM melatonin for 2 hours in medium. The cells were washed three times with PBS before fixation using 4% paraformaldehyde, followed by permeation using 0.5% Triton X‐100 for 15 minutes.…”

“…In the current study, we applied tert‐butyl hydroperoxide (TBHP), which is commonly used as an exogenous inducer of oxidative stress, to establish a pathological IDD condition in primary EPCs in vitro. We investigated the effects of melatonin on apoptosis and calcification in EPCs under oxidative stress and illustrated the possible mechanism of melatonin in ameliorating IDD processes.…”

BST106 Protects against Cartilage Damage by Inhibition of Apoptosis and Enhancement of Autophagy in Osteoarthritic Rats

“…47) Recently, Cetrullo et al demonstrated that autophagic flux was impaired by excessive oxidative stress in human chondrocytes. 48) In t-butyl hydroperoxide-treated-chondrocytes, trehalose attenuated apoptosis through restoration of autophagic flux via increased LC3-II and decreased p62 protein expression. 49) p62 acts as a cargo receptor for autophagic degradation and is a target gene for transcription factor, nuclear factor-E2-related factor 2 (Nrf2) creating a positive feedback loop by inducing antioxidant response element-driven gene transcription.…”