Background: Temporomandibular disorders (TMDs) are characterized by persistent orofacial pain and have diverse etiologic factors that are not well understood. It is thought that central sensitization leads to neuronal hyperexcitability and contributes to hyperalgesia and spontaneous pain. Nonsteroidal anti-inflammatory drugs (NSAIDs) are currently the first choice of drug to relieve TMD pain. NSAIDS were shown to exhibit anticonvulsant properties and suppress cortical neuron activities by enhancing neuronal voltage-gated potassium KCNQ/Kv7 channels (M-current), suggesting that specific activation of M-current might be beneficial for TMD pain. Results: In this study, we selected a new anticonvulsant drug retigabine that specifically activates M-current, and investigated the effect of retigabine on inflammation of the temporomandibular joint (TMJ) induced by complete Freund's adjuvant (CFA) in rats. The results show that the head withdrawal threshold for escape from mechanical stimulation applied to facial skin over the TMJ in inflamed rats was significantly lower than that in control rats. Administration of centrally acting M-channel opener retigabine (2.5 and 7.5 mg/kg) can dose-dependently raise the head withdrawal threshold of mechanical allodynia, and this analgesic effect can be reversed by the specific KCNQ channel blocker XE991 (3 mg/kg). Food intake is known to be negatively associated with TMJ inflammation. Food intake was increased significantly by the administration of retigabine (2.5 and 7.5 mg/kg), and this effect was reversed by XE991 (3 mg/kg). Furthermore, intracerebralventricular injection of retigabine further confirmed the analgesic effect of central retigabine on inflammatory TMJ. Conclusions: Our findings indicate that central sensitization is involved in inflammatory TMJ pain and pharmacological intervention for controlling central hyperexcitability by activation of neuronal KCNQ/M-channels may have therapeutic potential for TMDs.

The post-radiotherapy wounds are common in patients. The irradiation-induced reactive oxygen species (ROS) accumulation, nucleic acid damage, and inflammation greatly hinder wound healing. The irradiation-induced immunosuppression may further cause bacterial infection. At present, few dressings are available for infected wounds after radiotherapy (IWAR). In this study, a multifunctional hydrogel for IWAR has been developed by combining a positively-charged antioxidant polymer with the natural product baicalin. This hydrogel can smartly release baicalin under IWAR-like microenvironment and possesses broad-spectrum antibacterial properties. It has effectively prevented irradiation-induced intracellular ROS and nucleic acid damage to protect fibroblasts for tissue repair. In mice treated with IWAR, this hydrogel has inhibited infection caused by drug-resistant Pseudomonas aeruginosa, downregulated inflammation, and significantly accelerated wound healing (to more than 10 times the rate of untreated IWAR), achieving full-layer regeneration. This study obtains a multifunctional hydrogel for IWAR, and provides insights into the development of radiotherapy-related biomaterials.

Basic helix–loop–helix/helix–loop–helix (bHLH/HLH) transcription factors play substantial roles in plant cell elongation. In this study, two bHLH/HLH homologous proteins leaf related protein 1 and leaf-related protein 2 (AtLP1 and AtLP2) were identified in Arabidopsis thaliana. LP1 and LP2 play similar positive roles in longitudinal cell elongation. Both LP1 and LP2 overexpression plants exhibited long hypocotyls, elongated cotyledons, and particularly long leaf blades. The elongated leaves resulted from increased longitudinal cell elongation. lp1 and lp2 loss-of-function single mutants did not display distinct phenotypes, but the lp1lp2 double mutant showed decreased leaf length associated with less longitudinal polar cell elongation. Furthermore, the phenotype of lp1lp2 could be rescued by the expression of LP1 or LP2. Expression of genes related to cell elongation was upregulated in LP1 and LP2 overexpression plants but downregulated in lp1lp2 double mutant plants compared with that of wild type. LP1 and LP2 proteins could directly bind to the promoters of Longifolia1 (LNG1) and LNG2 to activate the expression of these cell elongation related genes. Both LP1 and LP2 could interact with two other bHLH/HLH proteins, IBH1 (ILI1 binding BHLH Protein1) and IBL1 (IBH1-like1), thereby suppressing the transcriptional activation of LP1 and LP2 to the target genes LNG1 and LNG2. Thus, our data suggested that LP1 and LP2 act as positive regulators to promote longitudinal cell elongation by activating the expression of LNG1 and LNG2 genes in Arabidopsis. Moreover, homodimerization of LP1 and LP2 may be essential for their function, and interaction between LP1/LP2 and other bHLH/HLH proteins may obstruct transcriptional regulation of target genes by LP1 and LP2.

Human jaw bone marrow mesenchymal stem cells (h-JBMMSCs) are multipotent progenitor cells with osteogenic differentiation potential. The relationship between adiponectin (APN) and the metabolism of h-JBMMSCs has not been fully elucidated, and the underlying mechanism remains unclear. The aim of the study was to investigate the effect and mechanism of APN on h-JBMMSC metabolism. h-JBMMSCs were obtained from the primary culture of human jaw bones and treated with or without APN (1 µg/mL). Osteogenesis-related gene expression was evaluated by real-time polymerase chain reaction (PCR), alkaline phosphatase (ALP) activity assay, and enzyme-linked immunosorbent assay (ELISA). To further investigate the signaling pathway, mechanistic studies were performed using Western blotting, immunofluorescence, lentiviral transduction, and SB202190 (a specific p38 inhibitor). Alizarin Red staining showed that APN promoted h-JBMMSC osteogenesis. Real-time PCR, ALP assay, and ELISA showed that ALP, osteocalcin (OCN), osteopontin, and integrin-binding sialoprotein were up-regulated in APN-treated cells compared to untreated controls. Immunofluorescence revealed that adaptor protein containing a pleckstrin homology domain, phosphotyrosine domain, and leucine zipper motif (APPL1) translocated from the nucleus to the cytoplasm with APN treatment. Additionally, the phosphorylation of p38 mitogen-activated protein kinase (MAPK) increased over time with APN treatment. Moreover, knockdown of APPL1 or p38 MAPK inhibition blocked the expression of APN-induced calcification-related genes including ALP, Runt-related transcription factor 2 (RUNX2), and OCN. Furthermore, Alizarin Red staining of calcium nodes was not increased by the knockdown of APPL1 or p38 inhibition. Our data suggest that this regulation is mediated through the APPL1–p38 MAPK signaling pathway. These findings collectively provide evidence that APN induces the osteogenesis of h-JBMMSCs through APPL1-mediated p38 MAPK activation.

Background and Aims: Chronic HBV infection is the leading cause of HCC and a serious health problem in China, East Asia, and North African countries. Effective treatment of HBV‐related HCC is currently unavailable. This study evaluated the therapeutic potential of T‐cell immunoreceptor with Ig and ITIM domains (TIGIT) blockade in HBV‐related HCC. Approach and Results: A mouse model of spontaneous HBV‐related HCC was generated by replacing wild‐type hepatocytes with HBsAg⁺ hepatocytes (namely HBs‐HepR mice). The tumors in HBs‐HepR mice were inflammation‐associated HCC, similar to HBV‐related HCC in patients, which was distinguished from other HCC mouse models, such as diethylnitrosamine‐induced HCC, TGF‐β‐activated kinase 1 knockout–induced HCC, HCC in a stelic animal model, or NASH‐induced HCC. HCC in HBs‐HepR mice was characterized by an increased number of CD8⁺ T cells, whereas the production of IL‐2, TNF‐α, and interferon‐gamma (IFN‐γ) by intrahepatic CD8⁺ T cells was decreased. Increased expression of TIGIT on CD8⁺ T cells was responsible for functional exhaustion. The therapeutic effect of TIGIT blockade was investigated at the early and middle stages of HCC progression in HBs‐HepR mice. TIGIT blockade reinvigorated intrahepatic CD8⁺ T cells with increased TNF‐α and IFN‐γ production and an increased number of CD8⁺ T cells in tumors, thereby slowing the development of HCC in HBs‐HepR mice. Blocking PD‐L1 did not show direct therapeutic effects or synergize with TIGIT blockade. Conclusions: Blockade of TIGIT alone enhanced the antitumor activity of CD8⁺ T cells during the progression of HBV‐related HCC in a spontaneous HCC mouse model.