miR-708-5p deficiency involves the degeneration of mandibular condylar chondrocytes via the TLR4/NF-κB pathway.

OBJECTIVE: Ageing and aberrant biomechanical stimulation are two major risk factors for osteoarthritis (OA). One of the main characteristics of aged cartilage is cellular senescence. One of the main characteristics of osteoarthritic joints is cartilage degeneration. The cells in the temporomandibular joint (TMJ) cartilage are zonally arranged. The deep zone cells are differentiated from the superficial zone cells (SZCs). The purpose of the present study was to investigate whether degenerative shear stress (SS) stimulates the senescence programme in TMJ SZCs, and to determine which miRNA is involved in this process. METHOD: SZCs were isolated from the TMJ condyles of 3-week-old rats and treated with continuous passaging or SS. RNA sequencing was conducted to identify miRNA(s) that overlap with those involved in the replication senescence process and the SS-induced degeneration programme. Unilateral anterior crossbite (UAC), which is TMJ-OA inducible, was applied to 2-month-old and 12-month-old mice for 3 weeks. The effect of TMJ local injection of agomiR-708-5p was evaluated histologically. RESULTS: Both replication and SS treatment induced SZC senescence. miR-708-5p was identified. Knocking down miR-708-5p in SS-treated SZCs led to more severe senescence by alleviating the inhibitory impact of miR-708-5p on the TLR4/NF-κB pathway. miR-708-5p expression in mouse TMJ cartilage decreased with age. UAC induced more severe osteoarthritic cartilage lesions in 12-month-old mice than in 2-month-old mice. Injection of agomiR-708-5p suppressed UAC-induced osteoarthritic cartilage lesions. CONCLUSIONS: Age-related miR-708-5p deficiency is involved in the mechanically stimulated OA process. Intra-articular administration of agomiR-708-5p is a promising new strategy for OA treatment.

CaSR modulates proliferation of the superficial zone cells in temporomandibular joint cartilage via the PTHrP nuclear localization sequence.

The superficial zone cells in mandibular condylar cartilage are proliferative. The present purpose was to delineate the relation of calcium-sensing receptor (CaSR) and parathyroid hormone-related peptide nuclear localization sequence (PTHrP87-139 ), and their role in the proliferation behaviors of the superficial zone cells. A gain- and loss-of-function strategy were used in an in vitro fluid flow shear stress (FFSS) model and an in vivo bilateral elevation bite model which showed mandibular condylar cartilage thickening. CaSR and PTHrP87-139 were modulated through treating the isolated superficial zone cells with activator/SiRNA and via deleting CaSR or parathyroid hormone-related peptide (PTHrP) gene in mice with the promoter gene of proteoglycan 4 (Prg4-CreERT2 ) in the tamoxifen-inducible pattern with or without additional injection of Cinacalcet, the CaSR agonist, or PTHrP87-139 peptide. FFSS stimulated CaSR and PTHrP expression, and accelerated proliferation of the Prg4-expressing superficial zone cells, in which process CaSR acted as an up-streamer of PTHrP. Proteoglycan 4 specific knockout of CaSR or PTHrP reduced the cartilage thickness, suppressed the proliferation and early differentiation of the superficial zone cells, and inhibited cartilage thickening and matrix production promoted by bilateral elevation bite. Injections of CaSR agonist Cinacalcet could not improve the phenotype caused by PTHrP mutation. Injections of PTHrP87-139 peptide rescued the cartilage from knockout of CaSR gene. CaSR modulates proliferation of the superficial zone cells in mandibular condylar cartilage through activation of PTHrP nuclear localization sequence. Our data support the therapeutic target of CaSR in promoting PTHrP production in superficial zone cartilage.

Zonal interdependence in the temporomandibular joint cartilage.

The temporomandibular joint (TMJ) cartilage is biomechanical sensitive. Cells in TMJ cartilage are zonally arranged, earlier differentiated in the super zone and late differentiated in the deep zone. The purpose was to detect the zonal interdependence in TMJ cartilage under dental biomechanical stimulations. Here, we obtained the Sox9CreER ; Rosa26tdTomato and Col10CreER ; Rosa26tdTomato mice to label super zone Sox9-expressing (Sox9+ ) or deep zone Col10-expressing (Col10+ ) cells by tdTomato (TdT), and Sox9CreER ; Rosa26DTA and Col10CreER ; Rosa26DTA mice to ablate Sox9+ or Col10+ cells selectively. These mice were subjected to unilateral anterior crossbite (UAC) or bilateral anterior elevation (BAE) dental stimulation, which promoted terminal differentiation or proliferation of TMJ chondrocytes, respectively. In both UAC and BAE models, the Sox9-TdT+ cells performed as proliferation and mature differentiation, showing as expressing Ki67 and Col-X, respectively; while the Col10-TdT+ cells performed as terminal differentiation, showing as expressing osteocalcin (OCN). In both Sox9+ - and Col10+ -cells ablation groups, there were reductions in cell number, cartilage thickness and matrix amount, subchondral bone loss, and condylar deformation. The UAC-promoted terminal differentiation was enhanced, and the BAE-promoted cellular proliferation was ruined. Impressively, when Col10+ cells were ablated, the UAC-promoted DAP3 expression, an anoikis marker, was further increased, while the BAE-suppressed DAP3 expression was instead greatly increased. These findings demonstrated that the cartilage zones function interdependently. The super zone harbors the cells that undergo differentiation to deep zone cells, the deep zone contains load-bearing matrix which is structural essential for the cells located inside or superficial.

A novel model for predicting prognosis in patients with idiopathic pulmonary fibrosis based on endoplasmic reticulum stress-related genes.

Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic disease of unknown pathogenic origin. Endoplasmic reticulum (ER) stress refers to the process by which cells take measures to ER function when the morphology and function of the reticulum are changed. Recent studies have demonstrated that the ER was involved in the evolution and progression of IPF. In this study, we obtained transcriptome data and relevant clinical information from the Gene Expression Omnibus database and conducted bioinformatics analysis. Among the 544 ER stress-related genes (ERSRGs), 78 were identified as differentially expressed genes (DEGs). These DEGs were primarily enriched in response to ER stress, protein binding, and protein processing. Two genes (HTRA2 and KTN1) were included for constructing an accurate molecular signature. The overall survival of patients was remarkably worse in the high-risk group than in the low-risk group. We further analyzed the difference in immune cells between high-risk and low-risk groups. M0 and M2 macrophages were significantly increased in the high-risk group. Our results suggested that ERSRGs might play a critical role in the development of IPF by regulating the immune microenvironment in the lungs, which provide new insights on predicting the prognosis of patients with IPF.

Low-frequency pulsed electromagnetic fields alleviate the condylar cartilage degeneration and synovitis at the early stage of temporomandibular joint osteoarthritis.

BACKGROUND: Temporomandibular joint osteoarthritis (TMJOA) is characterized by articular cartilage degeneration and progressive synovitis. How to effectively inhibit TMJOA in the early stage has been a hot topic in the biomedical field. As a non-invasive physiotherapy, pulsed electromagnetic field (PEMF) treatment has shown great potential in the treatment of osteoarthritis (OA) in extremity joints. OBJECTIVE: This study aims to investigate the biological effect of PEMF intervention on TMJ cartilage degeneration and synovium inflammation at the early stage of TMJOA. METHODS: PEMF (2.0 mT, 15 Hz, 2 h/day) treatment was given to rats in which TMJOA was induced by applying the unilateral anterior crossbite (UAC). Histological and immunohistochemical staining, TUNEL assay, real-time PCR and western blotting assay were performed to detect the changes of the morphology and the expression of pro-inflammatory and degradative factors in condylar cartilage and synovium. RESULTS: Obvious condylar cartilage degeneration, characterized by decreased cartilage thickness, degraded cartilage extracellular matrix, increased expression of pro-inflammatory and degradative factors (TNF-α, IL-1ß, MMP-13, ADAMTS-5, IL-6, MMP-3, MMP-9 and COL-X) and increased chondrocytes death, was observed in UAC group, accompanied by synovium hyperplasia and up-regulation of pro-inflammatory and degradative factors in synovium. PEMF intervention reversed the decreased cartilage thickness at 3 weeks and degraded cartilage extracellular matrix at 6 weeks. Moreover, the up-regulation of pro-inflammatory, degradative and hypertrophyic factors and chondrocytes death in condylar cartilage induced by UAC were inhibited to some extent. In addition, the synovium hyperplasia and the up-regulation of pro-inflammatory and degradative factors in synovium were inhibited at 3 weeks and 6 weeks. CONCLUSIONS: Appropriate PEMF stimulation can reverse the loss of cartilage extracellular matrix, the chondrocytes death, the increased expression of pro-inflammatory and degradative factors in cartilage, the decreased cartilage thickness and synovium inflammation induced by UAC at the early stage of TMJOA to some extent. PEMF stimulation may be a promising method in clinical TMJOA treatment.

Synthesis of and anti-fibrotic effect of pyrazole derivative J-1048: Inhibition of ALK5 as a novel approach to liver fibrosis targeting inflammation.

Liver fibrosis is a worldwide challenge of health issue. Developing effective new drugs for treating liver fibrosis is of great importance. In recent years, chemically synthesized drugs have significant advantages in treating liver fibrosis. Small molecule pyrazole derivatives as activin receptor-like kinase 5 (ALK5) inhibitors have also shown anti-fibrotic and tumor growth inhibitory effects. To develop the candidate with anti-fibrotic effect, we synthesized a novel pyrazole derivative, J-1048. The inhibitory effect of J-1048 on ALK5 and p38α mitogen-activated protein (MAP) kinase activity was assessed by enzymatic assays. We established an in vivo liver fibrosis model by injecting thioacetamide (TAA) into mice and in vitro model of TGF-ß stimulated hepatic stellated cells to explore the inhibition mechanisms and therapeutic potential of J-1048 as an ALK5 inhibitor in liver fibrosis. Our data showed that J-1048 inhibited TAA-induced liver fibrosis in mice by explicitly blocking the TGF-ß/Smad signaling pathway. Additionally, J-1048 inhibited the production of inflammatory cytokine Interleukin-1ß (IL-1ß) by inhibiting the purinergic ligand-gated ion channel 7 receptor (P2X7r) -Nucleotide-binding domain-(NOD-)like receptor protein 3 (NLRP3) axis, thereby alleviating liver fibrosis. Our findings demonstrated that a novel small molecule ALK5 inhibitor, J-1048, exhibited strong potential as a clinical therapeutic candidate for liver fibrosis.

Long-term effect of bilateral anterior elevation of occlusion on the temporomandibular joints.

OBJECTIVE: Incisors tubed prosthesis with bilateral anterior elevation (BAE) relation had been reported to stimulate the proliferative response in the mandibular condylar cartilage of mice, thus the prosthetic occlusion elevation had been proposed to treat cartilage degeneration. Currently, we aimed to detect the long-term effect of BAE on temporomandibular joints (TMJs). MATERIALS AND METHODS: Twelve 6-week-old female mice were assigned to age-matched control and BAE groups (n = 6). Micro-CT images and the macro- and micro-morphology of the mandibular condyles were analyzed at 29 weeks. RESULTS: Compared with the age-matched controls, in BAE group, there were loss of subchondral cortical bone and heavy loss of the subchondral trabecular bone at the superior sites of the TMJ condyles, but hyperostosis at the inferior sites as revealed by micro-CT images and histological slices. In BAE group, cartilage thickness and matrix area were increased with upregulated expression of type II, type X collagen, and Ki67, but the expression of cleaved caspase-3 was downregulated (all, p < 0.05). CONCLUSION: In addition to cartilage thickening, long-term BAE induces loss of the subchondral cortical bone and heavy loss of the underneath subchondral trabecular bone, but hyperostosis further underneath. Using BAE as a treatment remains double-edged.

Low frequency pulsed electromagnetic fields exposure alleviate the abnormal subchondral bone remodeling at the early stage of temporomandibular joint osteoarthritis.

BACKGROUND: Temporomandibular joint osteoarthritis (TMJOA) is characterized by abnormal subchondral bone remodeling and cartilage degeneration. As a non-invasive biophysical technology, pulsed electromagnetic field (PEMF) treatment has been proven to be efficient in promoting osteogenesis. However, the potential bone protective effect and mechanism of PEMF on abnormal subchondral bone remodeling in TMJOA are unknown. METHODS: Unilateral anterior crossbite (UAC) was used to create TMJOA model in rats, and 17ß-estradiol (E2) were injected daily to mimic patients with high-physiological levels of estrogen. Mouse osteoblast-like MC3T3-E1 cells treated with recombinant murine IL-1ß was used to establish inflammatory environment in vitro. The treatment group were subjected to PEMF (2.0mT, 15 Hz, 2 h/d). Micro-CT scanning, histological staining, real-time PCR and western blotting assays were preformed to observe the changes in the subchondral bone. RESULTS: Abnormal resorption of subchondral bone induced by UAC, characterized by decreased bone mineral density, increased osteoclast activity and expression of osteoclast-related factors (RANKL) and down-regulated expression of osteogenesis-related factors (OPG, ALP, Runx2 and OCN) at the early stage, could be reversed by PEMF exposure, which was similar to the effect of estrogen. In addition, PEMF exposure and E2 supplement may have a synergistic effect to some extent. Moreover, PEMF exposure could promote the ALP activity and osteogenic mineralization ability of MC3T3-E1 cells. PEMF promoted the expression of factors related to Wnt/ß-Catenin signal pathway both in vivo and in vitro. CONCLUSIONS: Appropriate PEMF exposure have a protective effect on subchondral bone in TMJOA at early stage, in which canonical Wnt/ß-Catenin pathway may be involved. PEMF may be a promising biophysical approach for early intervention of TMJOA in clinic.

Multi-modal trained artificial intelligence solution to triage chest X-ray for COVID-19 using pristine ground-truth, versus radiologists.

The front-line imaging modalities computed tomography (CT) and X-ray play important roles for triaging COVID patients. Thoracic CT has been accepted to have higher sensitivity than a chest X-ray for COVID diagnosis. Considering the limited access to resources (both hardware and trained personnel) and issues related to decontamination, CT may not be ideal for triaging suspected subjects. Artificial intelligence (AI) assisted X-ray based application for triaging and monitoring require experienced radiologists to identify COVID patients in a timely manner with the additional ability to delineate and quantify the disease region is seen as a promising solution for widespread clinical use. Our proposed solution differs from existing solutions presented by industry and academic communities. We demonstrate a functional AI model to triage by classifying and segmenting a single chest X-ray image, while the AI model is trained using both X-ray and CT data. We report on how such a multi-modal training process improves the solution compared to single modality (X-ray only) training. The multi-modal solution increases the AUC (area under the receiver operating characteristic curve) from 0.89 to 0.93 for a binary classification between COVID-19 and non-COVID-19 cases. It also positively impacts the Dice coefficient (0.59 to 0.62) for localizing the COVID-19 pathology. To compare the performance of experienced readers to the AI model, a reader study is also conducted. The AI model showed good consistency with respect to radiologists. The DICE score between two radiologists on the COVID group was 0.53 while the AI had a DICE value of 0.52 and 0.55 when compared to the segmentation done by the two radiologists separately. From a classification perspective, the AUCs of two readers was 0.87 and 0.81 while the AUC of the AI is 0.93 based on the reader study dataset. We also conducted a generalization study by comparing our method to the-state-art methods on independent datasets. The results show better performance from the proposed method. Leveraging multi-modal information for the development benefits the single-modal inferencing.

Effects of occlusion modification on the remodelling of degenerative mandibular condylar processes.

OBJECTIVE: The temporomandibular joint (TMJ) displays a high remodelling capability in response to occlusion changes. The purpose of the current study was to investigate the responses of TMJ condyles of growing mice to the installation of a unilateral anterior crossbite (UAC) prosthesis and the replacement of the UAC prothesis with a bilateral anterior elevation (BAE) prosthesis. MATERIALS AND METHODS: C57BL/6J mice were randomly assigned to the blank control and experimental groups. In mice in the experimental groups, UAC was created, while in others, BAE was created after the creation of UAC or removal of UAC. Changes in TMJ condylar cartilage and subchondral bone were assessed. RESULTS: The degradation of condylar cartilage induced by UAC was reversed by BAE, as evaluated by cartilage histochemical changes, collagen II-positive area, collagen X-positive chondrocytes and expression levels of Adamts-5, Mmp13, Tnf-α and Il-1ß. Subchondral bone was assessed based on the subchondral bone volume, the number of TRAP-positive cells and the Opg/Rankl ratio. CONCLUSION: The growing mouse TMJ condyle displays a high remodelling capability, which can be degenerative or rehabilitative in response to the creation of UAC and the replacement of UAC with BAE. Early correction of occlusion is beneficial for the recovery of degenerative condyles.

Bilateral anterior elevation prosthesis boosts chondrocytes proliferation in mice mandibular condyle.

OBJECTIVE: We aimed to develop a mouse model predominating in a proliferative response in the articular cartilage of the temporomandibular joints. MATERIALS AND METHODS: Bilateral anterior elevation of occlusion was developed by installing metal tubes onto the incisors of mice with edge-to-edge relation to prevent tooth wear, leading to an increase in the vertical height of the dental occlusion with time. Morphological changes and expression changes in Cyclin D1, Aggrecan, and type II and type X collagen in the mandibular condylar cartilage were detected. In addition, cells were isolated from the mandibular condylar cartilage and exposed to cyclic tensile strain (CTS). RESULTS: Compared with age-matched controls, the tooth length was longer at 3 weeks, 7 weeks, and 11 weeks in BAE mice (p < 0.05), with increased condylar cartilage thickness, matrix amount, and cell number (p < 0.05). Compared with the deep zone cells, CTS stimulated the superficial zone cells to express a higher level of proliferating cell nuclear antigen, Cyclin D1, Aggrecan, and type II collagen but a lower level of type X collagen and alkaline phosphatase. CONCLUSION: Bilateral anterior elevation stimulated the proliferative response in the mandibular condylar cartilage, offering a new therapeutic strategy for cartilage degeneration.

Early growth response 1 reduction in peripheral blood involving condylar subchondral bone loss.

OBJECTIVES: To detect whether early growth response 1 (EGR1) in peripheral blood leucocytes (PBLs) indicates temporomandibular joint (TMJ) osteoarthritis (OA) lesions. MATERIALS AND METHODS: Egr1 mRNA expression levels in PBLs were detected in eight malocclusion patients without temporomandibular disorder (TMD) signs and 16 malocclusion patients with clinical TMD signs with (eight) or without (eight) imaging signs of TMJ OA. Twelve 6-week-old rats were randomized to a control group and a unilateral anterior crossbite (UAC) group and were sampled at 4 weeks. The Egr1 mRNA expression levels in PBLs and protein expression levels in different orofacial tissues were measured. RESULTS: Patients with TMD signs with/without TMJ OA diagnosis showed lower Egr1 mRNA expression levels in PBLs than patients without TMD signs. The lower Egr1 mRNA expression was also found in the PBLs of UAC rats, which were induced to exhibit early histo-morphological signs of TMJ OA lesions. In subchondral bone of UAC rats, EGR1 protein expression was decreased, co-localization of EGR1 with osterix or dentin matrix protein-1 was identified, and the number of EGR1 and osterix double-positive cells was reduced (all p < .05). CONCLUSION: Egr1 reduction in PBLs potentially indicates subchondral bone OA lesions at an early stage.

Catabolic changes of rat temporomandibular joint discs induced by unilateral anterior crossbite.

BACKGROUND: The temporomandibular joint (TMJ) disc plays a role in joint movement and in load absorbance and distribution. An experimental unilateral anterior crossbite (UAC) prosthesis induces mandibular condylar cartilage degeneration in rats. However, the changes in the articular disc are still unknown. OBJECTIVE: To describe changes in the TMJ discs of UAC rats. METHODS: The discs of fifty-four Sprague-Dawley rats, equally distributed into a UAC group and an age-matched sham-operated control group at 4, 12 and 20 weeks (n = 9), were evaluated by gross and histomorphological observation and by detection at the mRNA or protein expression levels of the markers related to the matrix elements. RESULTS: No macro- or micro-morphological differences were observed between groups. However, there were catabolic degradative changes at the molecular level in the UAC group, showing a significant reduction in the mRNA and/or protein expression levels of many molecules. The reduction became worse with time (P < 0.05). The reduced molecules included: (a) those related to the extracellular matrix, such as type I collagen, decorin and fibromodulin; (b) those related to chondrogenesis, such as type II collagen and aggrecan; and (c) those related to osteogenesis, such as alkaline phosphatase and runt-related transcription factor 2. The mRNA expression of vascular endothelial growth factor did not change. In contrast, fibronectin, which can promote wound healing, and its N-terminal fragment, which can induce cartilage degradation, were accumulated (P < 0.05). CONCLUSION: TMJ discs were stimulated to catabolic changes by the aberrant dental occlusion and seemed to go to inanimate with time.

Molecular changes in peripheral blood involving osteoarthritic joint remodelling.

Biomarkers of temporomandibular joint (TMJ) osteoarthritis (OA) remain unknown. The objective was to detect whether molecular biomarkers from peripheral blood leucocytes (PBLs) engage in TMJ OA lesions. Thirty-four six-week-old Sprague Dawley rats were used. The top upregulated gene ontology categories and gene-fold changes in PBLs were detected by a microarray analysis comparing rats that received 20-week unilateral anterior crossbite (UAC) treatment with age-matched controls (n = 4). Twenty weeks of UAC treatment had been reported to induce TMJ OA-like lesions. The other twenty-four rats were randomly placed in the UAC and control groups at 12- and 20-week time points (n = 6). The mRNA expression levels of the selected biomarkers derived from the microarray analysis and their protein expression in the alveolar bone and TMJ were detected. The microarray analysis indicated that the three most highly involved genes in PBLs were Egr1, Ephx1 and Il10, which were confirmed by real-time PCR detection. The increased protein expression levels of the three detected molecules were demonstrated in cartilage and subchondral bone (P < 0.05), and increased levels of EPHX1 were reported in discs (P < 0.05); however, increased levels were not present in the alveolar bone. Immunohistochemistry revealed the increased distribution of EGR1-positive, EXPH1-positive and IL10-positive cells predominantly in the osteochondral interface, with EXPH1 also present in TMJ discs. In conclusion, the increased mRNA expression of Egr1, Ephx1 and Il10 in PBLs may serve as potential biomarkers for developed osteoarthritic lesions relating to osteochondral interface hardness changes induced by dental biomechanical stimulation.

Inhibition of Ihh Reverses Temporomandibular Joint Osteoarthritis via a PTH1R Signaling Dependent Mechanism.

The temporomandibular joint (TMJ), which is biomechanically related to dental occlusion, is often insulted by osteoarthritis (OA). This study was conducted to clarify the relationship between Indian hedgehog (Ihh) and parathyroid hormone receptor 1 (PTH1R) signaling in modulating the enhanced chondrocyte terminal differentiation in dental stimulated TMJ osteoarthritic cartilage. A gain- and loss-of-function strategy was used in an in vitro model in which fluid flow shear stress (FFSS) was applied, and in an in vivo model in which the unilateral anterior cross-bite (UAC) stimulation was adopted. Ihh and PTH1R signaling was modulated through treating the isolated chondrocytes with inhibitor/activator and via deleting Smoothened (Smo) and/or Pth1r genes in mice with the promoter gene of type 2 collagen (Col2-CreER) in the tamoxifen-inducible pattern. We found that both FFSS and UAC stimulation promoted the deep zone chondrocytes to undergo terminal differentiation, while cells in the superficial zone were robust. We demonstrated that the terminal differentiation process in deep zone chondrocytes promoted by FFSS and UAC was mediated by the enhanced Ihh signaling and declined PTH1R expression. The FFSS-promoted terminal differentiation was suppressed by administration of the Ihh inhibitor or PTH1R activator. The UAC-promoted chondrocytes terminal differentiation and OA-like lesions were rescued in Smo knockout, but were enhanced in Pth1r knockout mice. Importantly, the relieving effect of Smo knockout mice was attenuated when Pth1r knockout was also applied. Our data suggest a chondrocyte protective effect of suppressing Ihh signaling in TMJ OA cartilage which is dependent on PTH1R signaling.

Nrf2 Inhibits Periodontal Ligament Stem Cell Apoptosis under Excessive Oxidative Stress.

The present study aimed to analyze novel mechanisms underlying Nrf2-mediated anti-apoptosis in periodontal ligament stem cells (PDLSCs) in the periodontitis oxidative microenvironment. We created an oxidative stress model with H2O2-treated PDLSCs. We used real-time PCR, Western blotting, TUNEL staining, fluorogenic assay and transfer genetics to confirm the degree of oxidative stress and apoptosis as well as the function of nuclear factor-erythroid 2-related factor 2 (Nrf2). We demonstrated that with upregulated levels of reactive oxygen species (ROS) and malondialdehyde (MDA), the effect of oxidative stress was obvious under H2O2 treatment. Oxidative molecules were altered after the H2O2 exposure, whereby the signaling of Nrf2 was activated with an increase in its downstream effectors, heme oxygenase-1 (HO-1), NAD(P)H:quinone oxidoreductase 1 (NQO1) and γ-glutamyl cysteine synthetase (γ-GCS). Additionally, the apoptosis levels gradually increased with oxidative stress by the upregulation of caspase-9, caspase-3, Bax and c-Fos levels in addition to the downregulation of Bcl-2. However, there was no alterations in levels of caspase-8. The enhanced antioxidant effect could not mitigate the occurrence of apoptosis. Furthermore, Nrf2 overexpression effectively improved the anti-oxidative levels and increased cell proliferation. At the same time, overexpression effectively restrained TUNEL staining and decreased the molecular levels of caspase-9, caspase-3, Bax and c-Fos, but not that of caspase-8. In contrast, silencing the expression of Nrf2 levels had the opposite effect. Collectively, Nrf2 alleviates PDLSCs via its effects on regulating oxidative stress and anti-intrinsic apoptosis by the activation of oxidative enzymes.

Light mixed-supervised segmentation for 3D medical image data.

BACKGROUND: Accurate 3D semantic segmentation models are essential for many clinical applications. To train a model for 3D segmentation, voxel-level annotation is necessary, which is expensive to obtain due to laborious work and privacy protection. To accurately annotate 3D medical data, such as MRI, a common practice is to annotate the volumetric data in a slice-by-slice contouring way along principal axes. PURPOSE: In order to reduce the annotation effort in slices, weakly supervised learning with a bounding box (Bbox) was proposed to leverage the discriminating information via a tightness prior assumption. Nevertheless, this method requests accurate and tight Bboxes, which will significantly drop the performance when tightness is not held, that is when a relaxed Bbox is applied. Therefore, there is a need to train a stable model based on relaxed Bbox annotation. METHODS: This paper presents a mixed-supervised training strategy to reduce the annotation effort for 3D segmentation tasks. In the proposed approach, a fully annotated contour is only required for a single slice of the volume. In contrast, the rest of the slices with targets are annotated with relaxed Bboxes. This mixed-supervised method adopts fully supervised learning, relaxed Bbox prior, and contrastive learning during the training, which ensures the network exploits the discriminative information of the training volumes properly. The proposed method was evaluated on two public 3D medical imaging datasets (MRI prostate dataset and Vestibular Schwannoma [VS] dataset). RESULTS: The proposed method obtained a high segmentation Dice score of 85.3% on an MRI prostate dataset and 83.3% on a VS dataset with relaxed Bbox annotation, which are close to a fully supervised model. Moreover, with the same relaxed Bbox annotations, the proposed method outperforms the state-of-the-art methods. More importantly, the model performance is stable when the accuracy of Bbox annotation varies. CONCLUSIONS: The presented study proposes a method based on a mixed-supervised learning method in 3D medical imaging. The benefit will be stable segmentation of the target in 3D images with low accurate annotation requirement, which leads to easier model training on large-scale datasets.

Targeting RXFP1 by Ligustilide: A novel therapeutic approach for alcoholic hepatic steatosis.

BACKGROUND: Ligustilide (Lig) is the main active ingredient of Umbelliferae Angelicae Sinensis Radix (Chinese Angelica) and Chuanxiong Rhizoma (Sichuan lovase rhizome). Lig possesses various pharmacological properties and could treat obesity by regulating energy metabolism. However, the impact and regulatory mechanism of Lig on alcoholic hepatic steatosis remains unclear. PURPOSE: This study aimed to explore the therapeutic effect of Lig on alcoholic hepatic steatosis and its related pharmacological mechanism. RESULTS: With chronic and binge ethanol feeding, liver tissue damage and lipid accumulation in mice suffering alcoholic hepatic steatosis were significantly improved after Lig treatment. Lig effectively regulated the expression levels of lipid metabolism-related proteins in alcoholic hepatic steatosis. In addition, Lig reduced RXFP1 expression, inhibited the activation of NLRP3 inflammasome, and blocked NET formation. Lig reduced the infiltration of immune cells to the liver and the further prevented the occurrence of alcohol-stimulated inflammatory response in liver. Lig significantly regulated lipid accumulation in alcohol exposed AML12 cells via modulating PPARα and SREBP1. In MPMs, Lig decreased the expression of RXFP1, inhibited the activation of NLRP3 in macrophages stimulated by LPS/ATP, and slowed down the occurrence of inflammatory response. CONCLUSION: Lig sustained lipid metabolism homeostasis in alcoholic hepatic steatosis, through inhibiting the activation of NLRP3 inflammasomes and the formation of NETs, especially targeting RXFP1 in macrophages.

Study on the interaction mechanism of 2-aminoanthraquinone with calf thymus DNA.

By utilizing multispectrosopic techniques, the toxic interaction of 2-aminoanthraquinone (2-AAQ) with calf thymus deoxyribonucleic acid (ctDNA) was investigated in vitro under simulated physiological conditions. The experimental results proved that 2-AAQ has a toxic interaction with ctDNA. The binding capacity of DNA with 2-AAQ is diminishing as the pH value of system increasing in the optimization of experimental condition. Moreover we selected pH 7.4, which is nearly physiological condition to enhance the practical significance. According to the Stern-Volmer equation, the quenching was the static quenching process. And the quenching constant Kq can be derived from the fluorescence quenching spectrogram. Ultraviolet absorption spectra and the change in the fluorescence intensity at different ionic strengths further indicated that there was electrostatic binding between 2-AAQ and ctDNA. The circular dichroism experiment showed that the DNA conformation varied from B to A conformation. The basic group enhanced after 2-AAQ embedding. The double helix is more compact, and the DNA conformation changes.