[Research progress of necroptosis on bone related diseases].

As a new type of cell death, necroptosis is initiated by tumor necrosis factor receptor 1(TNFR1), and then activated receptor-interacting protein kinase 1(RIP1) and receptor-interacting protein kinase 3 (RIP3), following by the activation of mixed lineage kinase domain-like protein(MLKL) to deliver cell death signal. When necroptosis happens, damage associated molecular patterns (DAMPs) enter into extracellular area through the ruptured cytomembrane, followed by the disordered tissue hemeostasis. In recent years, many researches showed that necroptosis playimportant roles in a few bone related diseases, such as osteoporosis, osteonecrosis, osteosarcoma, etc.

Conditional deletion of Adrb2 in mesenchymal stem cells attenuates osteoarthritis-like defects in temporomandibular joint.

β2-adrenergic signal transduction in mesenchymal stem cells (MSCs) induces subchondral bone loss in osteoarthritis (OA) of temporomandibular joints (TMJs). However, whether conditional deletion of β2-adrenergic receptor (Adrb2) in nestin MSCs can alleviate TMJ-OA development remains unknown. In this study, nestin-Cre mice were crossed with Adrb2 flox mice to generate mice lacking Adrb2 expression specifically in the nestin MSCs (Adrb2), and TMJ-OA development in such mice was investigated.

Injury responses of Sprague-Dawley rat jaw muscles to an experimental unilateral anterior crossbite prosthesis.

Objective: Dental occlusion are frequently changed in clinic. Molecular responses in jaw muscles to aberrant dental occlusion are changes are attractive, yet remain are obscure.

Design: Unilateral anterior crossbite (UAC) prostheses were applied to Sprague-Dawley rats and then ceased after two weeks to detect the reactions of the masseter, a representative jaw elevator, and the lateral pterygoid muscle (LPM), a representative jaw depressor.

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.

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.

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.

Proteomics based detection of differentially expressed proteins in human osteoblasts subjected to mechanical stress.

Mechanical stress is essential for bone development. Mechanical stimuli are transduced to biochemical signals that regulate proliferation, differentiation, and cytoskeletal reorganization in osteoblasts. In this study, we used proteomics to evaluate differences in the protein expression profiles of untreated Saos-2 osteoblast cells and Saos-2 cells subjected to mechanical stress loading.

Enhancement of chondrocyte autophagy is an early response in the degenerative cartilage of the temporomandibular joint to biomechanical dental stimulation.

Autophagy is a cell protective mechanism for maintaining cellular homeostasis. The present study aimed to investigate whether autophagy is enhanced in the biomechanically induced degenerative cartilage of the temporomandibular joint (TMJ) and the potential role of mitogen-activated protein kinase kinase kinase kinase 3 (MAP4K3) and mammalian Target of rapamycin (mTOR) in this observation. To induce degenerative changes in the TMJs, rats were subjected to biomechanical dental stimulation by moving 4 molars away from their original position as we previously reported.

Changes of myelinated nerve and myelin basic protein expression in rats' periodontal ligaments after experimental tooth movement.

Introduction: Information about the effect of tooth movement on the myelinated nerve in the periodontal ligament is limited. In this study, we aimed to investigate what responses of the periodontal myelinated nerve can be evoked during experimental tooth movement.

Methods: In experimental-I group, the maxillary left and mandibular right third molars were moved distally.

Degenerative changes in rat condylar cartilage induced by non-matching occlusion created by scattered orthodontic teeth-moving.

The effect of occlusion on the temporomandibular joint (TMJ) is debated. By inserting rubber-bands that were replaced by self-curing resin one week later, the left maxillary and the right mandibular first-molars were moved and kept mesially in Sprague-Dawley (SD) rats in both experimental I (EXP-I) and II (EXP-II) groups, aiming to establish a non-matching cusp-to-fossa occlusal relation. Four weeks later, the left maxillary and the right mandibular third-molars were moved and kept distally in the EXP-II group.

Effect of estrogen and dietary loading on condylar cartilage.

Aims: To study the effect of estrogen deficiency and altered temporomandibular joint loading on the histomorphology of condylar cartilage and on the expression of types II and X collagen and matrix metalloproteinase-3 (MMP-3).

Methods: Thirty-six female rats were divided into four groups: ovariectomized rats on a normal diet, nonovariectomized control rats on a normal diet, ovariectomized rats on a soft diet, and nonovariectomized control rats on a soft diet. Ovariectomy was performed at the age of 60 days.

Excess genistein suppresses the synthesis of extracellular matrix in female rat mandibular condylar cartilage.

Aim: To investigate the effect of excess genistein on the extracellular matrix in mandibular condylar cartilage of female rats in vivo.

Methods: Female SD rats were administered through oral gavage with genistein (50 mg/kg) or placebo daily for 6 weeks. The morphological changes of temporomandibular joints were studied with HE staining.

[Effect of experimentally created disordered occlusion on the expression of IL-1β, IL-6 and TNF-α in condylar cartilage of rats].

Purpose: To investigate the effect of the experimentally created malocclusion (ECDO) on the expression of IL-1β, IL-6 and TNF-α in mandibular condylar cartilage of Sprague Dawley (SD) rats.

Methods: In the experimental group, the malocclusion was created by moving the first and third molars 0.8 mm away.

Osteochondral angiogenesis in rat mandibular condyles with osteoarthritis-like changes.

Objective: To investigate angiogenesis at the osteochondral junction and changes in expression of pro- and anti-angiogenic factors in rat mandibular condyles with osteoarthritis-like changes.

Methods: In order to evoke osteoarthritis-like lesions in mandibular condyles, disordered occlusion was created experimentally in rats. Osteochondral vascularity was assessed histologically at 20 and 24 weeks.

Dose-dependent effects of genistein on bone homeostasis in rats' mandibular subchondral bone.

Aim: To investigate the effect of genistein on bone homeostasis in mandibular subchondral bone of rats.

Methods: Female SD rats were administered with genistein (10 and 50 mg/kg) or placebo by oral gavage for 6 weeks. Then the animals were sacrificed, and histomorphology and micro-structure of mandibular condyle were examined using HE staining and micro-CT analysis, respectively.

Effect of estrogen and altered diet hardness on the expression of estrogen receptor alpha and matrix metalloproteinase-8 in rat condylar cartilage.

Aims: To examine the effect of decreased estrogen level and altered diet hardness on condylar cartilage morphology of the rat temporomandibular joint (TMJ) and on the expression of condylar cartilage estrogen receptor alpha (ERa) and matrix metalloproteinase-8 (MMP-8).

Methods: A total of 36 female rats was divided into four groups: ovariectomized rats fed a normal diet, non-ovariectomized controls fed a normal diet, ovariectomized rats fed a soft diet, and non-ovariectomized controls fed a soft diet. Ovariectomy was performed at the age of 60 days.

A novel recombinant immuno-tBid with a furin site effectively suppresses the growth of HER2-positive osteosarcoma cells in vitro.

Immunotherapy is a promising strategy for the treatment of human epidermal growth factor receptor 2 (HER2)-positive tumors. Previously, we constructed an immuno-carboxy terminal fragment of Bid (immuno-tBid) and reported its specific and effective destruction of HER2-positive tumor cells. In this study, in order to further reduce the immunogenicity of the previous immuno-proapoptotic protein, we constructed a novel immuno-tBid by replacing domain II of Pseudomonas exotoxin A with a short furin cleavage sequence from the diphtheria toxin.

Subchondral bone loss following orthodontically induced cartilage degradation in the mandibular condyles of rats.

Osteoarthritis (OA) is a degenerative joint disease generally characterized by progressive cartilage degradation and subchondral bone changes. Subchondral bone changes have been proposed to initiate or accompany with cartilage degradation in OA. The purpose of this study was to characterize cartilage damage, subchondral bone remodeling, and the possible mechanism involved in these morphological changes in our reported rat model with OA-like lesions in the mandibular condyle.

Changes in the expression of MMP-3, MMP-9, TIMP-1 and aggrecan in the condylar cartilage of rats induced by experimentally created disordered occlusion.

Objective: To investigate the effects of experimentally created disordered occlusion on the mandibular condylar cartilage in terms of histological morphology and expression of MMP-3, MMP-9, TIMP-1 and aggrecan.

Materials And Methods: Eighty 8-week-old Sprague-Dawley rats were randomly divided into two experimental (Exp) and two control (Con) groups, with equal sex and number distribution as subgroups. In the Exp group, the disordered occlusion was created by orthodontically moving the first and third molars 0.

Mandibular condylar cartilage response to moving 2 molars in rats.

Introduction: The purpose of this study was to investigate the responses of mandibular condylar cartilage to moving 2 molars in different combinations.

Methods: Rats were assigned to male and female control and experimental groups (each, n = 5). Elastic rubber bands were used to move medially the maxillary left and the mandibular right first molars in experimental group I.

Age- and sex-related changes of mandibular condylar cartilage and subchondral bone: a histomorphometric and micro-CT study in rats.

Objective: To quantify the age- and sex-related changes in the rat condylar cartilage and subchondral bone.

Methods: SD rats were obtained at the ages of 2, 3, 4, 5, 6 and 7 months. For each sex, the temporomandibular joints tissue blocks from four rats were subjected to histological assessment of cartilage thickness and subchondral bone architecture; for the remaining three rats, the mandibular condyles were delivered for gross measurement and evaluation of the mineralization and architecture properties of the subchondral bone by means of micro-CT.

[Effect of experimentally created occlusal disorders on the expression of estrogen in rat condylar cartilage].

Objective: To investigate the effect of experimentally created occlusal disorders (ECOD) on the expression of estrogen in rat condylar cartilage.

Methods: The model of ECOD was created by moving right upper and left lower first molars anteriorly. The animals in ECOD were sacrificed at 2, 4, 6, 8 weeks later.

Root canal morphology of permanent maxillary teeth in the Han nationality in Chinese Guanzhong area: a new modified root canal staining technique.

Introduction: The purpose of this study was to investigate the canal morphology of 504 maxillary permanent teeth of subjects of Han nationality in Chinese Guanzhong area.

Methods: Maxillary permanent teeth were randomly collected in Guanzhong area. After regular preparation, the teeth were immersed into ink without preparing access cavities and then put into hyperbaric oxygen chamber (0.

The effects of age and sex on the expression of oestrogen and its receptors in rat mandibular condylar cartilages.

Objective: Oestrogen expression may indicate a difference in resistance potential to mechanical strain. The purpose of this study was to investigate the expression of oestrogen and oestrogen receptors in mandibular condylar cartilages in male and female Sprague-Dawley rats at different ages.

Materials And Methods: One-hundred SD rats at the age of 2, 4, 8 weeks and 4, 12 months in both sexes, 10 in each age-sex group, were enrolled in this study.

[Expression feature and bioinformatic analysis of molar root patterning gene 1].

Objective: To examine the expression of molar root patterning gene 1 (Mrp1) and predict the Mrp1 structure by bioinformatics analysis.

Methods: A pair of Mrp1-specific PCR primers were designed, and RT-PCR method was used to study the mRNA's expression pattern in rat molar root and other organs. Gene positioning and other protein sequence prediction were carried out by chromosome analysis and other bioinformatics analysis.