Increased joint loading induces subchondral bone loss of the temporomandibular joint via the RANTES-CCRs-Akt2 axis.

Early-stage temporomandibular joint osteoarthritis (TMJOA) is characterized by excessive subchondral bone loss. Emerging evidence suggests that TMJ disc displacement is involved, but the pathogenic mechanism remains unclear. Here, we established a rat model of TMJOA that simulated disc displacement with a capacitance-based force-sensing system to directly measure articular surface pressure in vivo. Micro-CT, histological staining, immunofluorescence staining, IHC staining, and Western blot were used to assess pathological changes and underlying mechanisms of TMJOA in the rat model in vivo as well as in RAW264.7 cells in vitro. We found that disc displacement led to significantly higher pressure on the articular surface, which caused rapid subchondral bone loss via activation of the RANTES-chemokine receptors-Akt2 (RANTES-CCRs-Akt2) axis. Inhibition of RANTES or Akt2 attenuated subchondral bone loss and resulted in improved subchondral bone microstructure. Cytological studies substantiated that RANTES regulated osteoclast formation by binding to its receptor CCRs and activating the Akt2 pathway. The clinical evidence further supported that RANTES was a potential biomarker for predicting subchondral bone loss in early-stage TMJOA. Taken together, this study demonstrates important functions of the RANTES-CCRs-Akt2 axis in the regulation of subchondral bone remodeling and provides further knowledge of how disc displacement causes TMJOA.

Complete mitochondrial genome of Dibranchus japonicus (Actinopterygii, Lophiiformes, Ogcocephalidae), from the West Pacific Ocean.

Dibranchus japonicus is a benthic fish living in the deep Pacific Ocean. Here, we described the complete mitochondrial genome of this species, with the sequences about 17,233 bp in length, containing 13 protein-coding genes (PCGs), 22 tRNAs, and two rRNAs. The gene arrangement of this species was identical with others from family Ogcocephalidae. The content of GC and AT for D. japonicus was 45.41% and 54.59%, respectively. Phylogenetic analysis, based on 13 PCGs and two rRNA genes, revealed the close relationship between D. japonicus and other species of Ogcocephalidae, which was consistent with the morphology.

The complete mitochondrial genome of Oplophorus spinosus (Brullé, 1839) (Caridea, Oplophoridae).

We determined the complete mitochondrial genome of Oplophorus spinosus with a typical circular structure. The complete mitogenomes of O. spinosus was 17,346 bp in length, with 37 genes containing 13 protein-coding genes, 22 tRNAs, two rRNAs, and a confirmed D-loop zone. The GC content of O. spinosus was 34.39%. The phylogenetic results showed that O. spinosus was most closed to O. typus, providing useful mitochondrial information for its further evolutionary and taxonomy study.