Objectives The mechanisms underlying the effects of Toll‐like receptor 9 (TLR9) and autophagy on rheumatoid arthritis (RA)‐aggravated periodontitis are unclear. We aimed to explore a novel target, cathepsin K (Ctsk)‐mediated TLR9‐related autophagy, during the progress of periodontitis with RA. Materials and Methods DBA/J1 mouse model of periodontitis with RA was created by local colonization of Porphyromonas gingivalis (Pg) and injection of collagen. The expression of Ctsk was inhibited by adeno‐associated virus (AAV). Micro‐CT, immunohistochemistry (IHC), Western blot and quantitative real‐time polymerase chain reaction (qRT‐PCR) were used to detect the expression of TLR9‐related autophagy in periodontitis with RA. Small interfering RNA (siRNA) and CpG oligodeoxynucleotides (CpG ODN) were applied in macrophages. Western blot, immunofluorescence (IF) and qRT‐PCR were used to verify the in vivo results. Results RA can promote periodontitis bone destruction in the lesion area, while inhibiting Ctsk could effectively alleviate this effect. The infiltration of macrophages, TLR9, autophagy proteins (TFEB and LC3) and inflammatory cytokines increased in the periodontitis‐with‐RA group and was reduced by the inhibition of Ctsk in the periodontal region. Macrophage stimulation confirmed the in vivo results. With the activation of TLR9 by CpG ODN, inhibition of Ctsk could suppress both TLR9 downstream signalling proteins and autophagy‐related proteins. Conclusions This study advanced a novel role for Ctsk in TLR9 and autophagy to explain the interaction between periodontitis and RA.

Aim This study aimed at exploring changes in YAP expression and their effect on periodontitis (PD) combined with traumatic occlusion (TO). Materials and Methods BALB/cJ mice were used to establish a PD model by local administration of Porphyromonas gingivalis (P.g, ATCC 33277) and a TO model by occlusal elevation (OE) using composite resin bonding on the bilateral maxillary molar. The mouse fibroblast cell line (L929) and pre‐osteoblast cell line (MC3T3‐E1) were subjected to cyclic tensile/compressive stress and inflammatory stimuli (lipopolysaccharide from Escherichia coli) to verify in vivo results. Results Severe bone resorption was observed by microCT scanning in OE with P.g group, when compared to OE only and P.g only groups. Mechanical stress caused by OE activated the Hippo‐YAP pathway in periodontal tissues and upregulated the expression of JNK/AP‐1. OE with P.g further promoted the expression of YAP and JNK/AP1, leading to the upregulation of the JNK/AP‐1 related inflammatory cytokines TNF‐α and IL6. Similar results were obtained when osteoblasts were subjected to mechanical stress in vitro. Conclusions Our study demonstrated that periodontitis with TO caused severe inflammation‐induced bone resorption. Activation of YAP and upregulation of JNK/AP‐1 induced by TO potentially aggravated the symptoms of PD.

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PurposeWe aimed to assess the current status of depressive symptoms and quality of life (QoL) among rural elderly in central China (Anhui Province) and explore their correlation and associated factors for depressive symptoms.MethodsA multi-stage random sampling method was used to obtain 3349 participants (aged ≥60): 1206 poor and 2143 non-poor. The 30-item Geriatric Depression Scale (GDS-30) and five-dimensional European quality of health scale (EQ-5D) were employed to evaluate depressive symptoms and QoL, respectively.ResultsThe prevalence of depressive symptoms was 52.9%, and that in the poor group (62.3%) was significantly higher than the non-poor group (47.6%). The GDS-30 score was 12.40 ± 7.089, and the poor group scored significantly higher (14.045 ± 6.929) than the non-poor group (11.472 ± 7.011). The EQ-5D score was 0.713 ± 0.186, and the poor group (0.668 ± 0.192) scored significantly lower than the non-poor group (0.738 ± 0.178). There was a significant negative correlation between depressive symptoms and QoL (r = −0.400, P-value <0.05). The following factors were associated with depressive symptoms: poverty, low EQ-5D score, female gender, older age, illiteracy, unemployed, chronic diseases, and hospitalization in previous year.ConclusionRural elderly in central China have a high prevalence of depressive symptoms and low QoL. Poverty was associated with a higher prevalence of depressive symptoms and lower QoL.