BACKGROUND:Connexin 43(Cx43),which is thought to be engaged in the gap junction process and build the structural groundwork for the development of direct material signaling channels between cells,is crucial for maintaining the homeostatic balance of tissue metabolism.Recent research,however,has revealed fresh information about its distinct hemichannel function and highlighted the significance of its subcellular localization and self-fragmentation for cellular physiological activities and pathological processes. OBJECTIVE:To systematically summarize the molecular characteristics and expression of Cx43 in a variety of cells,concentrate on the pathological and physiological roles of channel-dependent Cx43 and channel-independent Cx43,and investigate the potential value in disease treatment by reviewing the pertinent literature in the database. METHODS:The Chinese and English keywords were"gap junction,connexin 43(Cx43),hemichannel,channel-dependent Cx43,channel-independent Cx43,extracellular vesicles(EVs),mitochondria,GJA1-20k",which were searched in PubMed and CNKI.Finally,81 articles were selected for review. RESULTS AND CONCLUSION:(1)The canonical role of Cx43 is to form a gap junction channel.Channel-dependent Cx43 has primarily involved in disease physiopathological processes by directly constituting gap junction channels,but full attention should be paid to the issue of its structural and functional integrity.Adhesion is a crucial characteristic of gap junctions,which are strongly associated with barrier-like diseases.(2)The non-canonical role of Cx43 is non-gap junction channel-dependent effect.In addition to being localized at the plasma membrane,inner mitochondrial membrane,extracellular vesicle surface,and other structures,Cx43 hexamer has also been found to play a role in positive pro-inflammatory mechanisms,mitochondrial functional metabolism,and targeted uptake of extracellular vesicles in inflammatory diseases.Selective shortened segments control mitochondrial homeostasis by encouraging the polymerization of peri-mitochondrial actin and are involved in the targeted translocation of full-length Cx43 to intracellular structural domains.(3)The development of targeted medicines and the solving of issues like the mechanism of seed cell transformation in tissue engineering-based therapies are both made possible by these two categories of impacts.The interactions of various types of Cx43,however,are frequently not fully taken into account in some of the existing original studies,which confuses the overall characteristics and skews the results.(4)It is necessary to systematically frame the physiological characteristics of Cx43 in different forms and its potential mechanisms in various diseases,so as to provide a reference for the exploration of the Cx43 integrity mechanism and the diagnosis and treatment of multiple diseases.

Objective The effect of different oxygen tensions on the cytoskeleton remodeling of goat temporomandibular joint (TMJ) disc cells were investigated. Methods Goat TMJ disc cells were cultured under normoxia (21% O₂) and hypoxia (2%, 4%, and 8% O₂). Toluidine blue, picrosirius red, and type Ⅰ collagen immunocytochemical staining were performed to observe the changes in cell phenotype under different oxygen levels. Immunofluorescent staining and real-time reverse transcription-polymerase chain reaction analysis were then performed to identify actin, tubulin, and vimentin in the cultured disc cells. Results TMJ disc cells still displayed fibroblast characteristics under different oxygen levels and their cytoskeletons had regular arrangement. The fluorescence intensities of actin and vimentin were lowest at 4% O₂(P<0.05), whereas that of tubulin was highest at 2% O₂ (P<0.05). No significant difference among the other groups was observed (P>0.05). Actin mRNA levels were considerably decreased at 2% O₂ and 4% O₂ in hypoxic conditions, while actin mRNA expression was highest in 21% O₂. Tubulin mRNA levels considerably increased at 2% O₂, while tubulin mRNA expression was lowest in 8% O₂ (P<0.05). Vimentin mRNA expression was lowest at 4% O₂ and highest at 21% O₂, and significant differences were observed between vimentin mRNA expression levels among these oxygen levels (P<0.05). Conclusion Cytoskeletons were reconstructed in different oxygen tensions, and 2% O₂ may be the optimal oxygen level required to proliferate TMJ disc cells.

OBJECTIVETo establish objectively biomechanical criteria for temporomandibular joint disc tissue engineerings.

METHODSEight temporomandibular joint discs from a four-month-old goat were separated completely. A cylindrical sample with diameter of 3 mm in the anterior, intermediate, and posterior bands was obtained, and the samples underwent pre-compression test with three cycles under a speed of 0.025 mm · s⁻¹. With the end condition for the maximum load of less than 4.9 N and 1.5 mm compression displacement, the formal compression test was performed with the same speed. Moreover, this test obtained the stress-strain relationship and elastic modulus of each disc band. Ultrastructure and collagen fiber orientation of the district zone were observed by scanning electron microscope and polarized light microscope.

RESULTS1) The physiological strain range of an articular disc was within 10%, and the quasilinear constitutive equation of articular disc tissues can be fitted with the polynomial function: y = ax + bx² + cx³. 2) The elastic modulus of the intermediate disc zone was the largest (P < 0.05). No significant difference existed between the anterior and posterior bands (P = 0.361). 3) Scanning electron microscope and polarized light microscope showed an annular disc collagen network structure, which was the internal part of the goat temporomandibular joint disc. The collagen arrangement of intermediate bands was tensely arranged anterior-posteriorly. The collagen of anterior and posterior bands went through mediolaterally with intersection of anterior-posterior branch fibersd.

CONCLUSIONAnnular collagen network structure is the basis for goat temporomandibular joint disc compression resistance properties. The intermediate band demonstrated higher compression resistance performance than the anterior and posterior bands.

To establish objectively biomechanical criteria for temporomandibular joint disc tissue engineerings. Methods Eight temporomandibular joint discs from a four-month-old goat were separated completely. A cylindrical sample with diameter of 3 mm in the anterior, intermediate, and posterior bands was obtained, and the samples underwent pre-compression test with three cycles under a speed of 0.025 mm·s?1. With the end condition for the maximum load of less than 4.9 N and 1.5 mm compression displacement, the formal compression test was performed with the same speed. Moreover, this test obtained the stress–strain relationship and elastic modulus of each disc band. Ultrastructure and collagen fiber orientation of the district zone were observed by scanning electron microscope and polarized light microscope. Results 1) The physiological strain range of an articular disc was within 10%, and the quasilinear constitutive equation of articular disc tissues can be fitted with the polynomial function: y=ax+bx2+cx3. 2) The elastic modulus of the intermediate disc zone was the largest (P<0.05). No significant difference existed between the anterior and posterior bands (P=0.361). 3) Scanning electron microscope and polarized light microscope showed an annular disc collagen network structure, which was the internal part of the goat temporomandibular joint disc. The collagen arrangement of intermediate bands was tensely arranged anterior–posteriorly. The collagen of anterior and posterior bands went through mediolaterally with intersection of anterior-posterior branch fibersd. Conclusion Annular collagen network structure is the basis for goat temporomandibular joint disc compression resistance properties. The intermediate band demonstrated higher compression resistance performance than the anterior and posterior bands.

OBJECTIVEThis study is performed to investigate the cell topographies and biomechanical properties of two different types of temporomandibular joint (TMJ) discs from goats by using JPK Nano Wizard 3 biological atomic force microscopy (AFM). This process provides a guideline for selecting seed cells for TMJ disc tissue engineering.

METHODSTMJ disc cells from primary goats were cultured by monolayer culture method. AFM was used to contact scan the topographies of the two types of TMJ disc cells under physiological environment. Approximately 20 chondrocyte-like and fibroblast-like cells were selected randomly to plot the force-versus-distance curves of the cytoplasm and nucleus. Young's modulus and adhesion were analyzed by JPK Data Processing.

RESULTSThe triangle-shapednucleus of the chondrocyte-like cell occupied a large portion of the cell. Cytoskeleton was arranged dendritically on the surface. Pseudopodia were extended from cell edges. The spindle-shaped nucleus of the fibroblast-like cell occupied a significantly larger region compared with the cytoplasmic region. Cytoskeleton was arranged regularly. Cell edges were smooth with less pseudopodia extended. No difference was found in the surface roughness between the two types of cells. According to the force-versus-distance curves, the Young's moduli of the two types of cells were not statistically different (P>0.05), but differences were found in the cytoplasmic regions (P=0.047). No statistical difference was found in the adhesions between the two types of cells (P>0.05).

CONCLUSIONThe AFM topography and curves were compared and analyzed. The two types of TMJ disc cells exhibited significantly different topographies, but only slight difference in their mechanical abilities.

Objective??This?study?is?performed?to?investigate?the?cell?topographies?and?biomechanical?properties?of?two?different?types?of?temporomandibular?joint?(TMJ)?discs?from?goats?by?using?JPK?Nano?Wizard?3?biological?atomic?force?microscopy?(AFM).?This?process?provides?a?guideline?for?selecting?seed?cells?for?TMJ?disc?tissue?engineering. Methods??TMJ?disc?cells?from?primary?goats?were?cultured?by?monolayer?culture?method.?AFM?was?used?to?contact?scan?the?topographies?of?the?two?types?of?TMJ?disc?cells?under?physiological?environment.?Approximately?20?chondrocyte-like?and?fibroblast-like?cells?were?selected?randomly?to?plot?the?force-versus-distance?curves?of?the?cytoplasm?and?nucleus.?Young’s?modulus?and?adhesion?were?analyzed?by?JPK?Data?Processing.?Results??The?triangle-shapednucleus?of?the?chondrocyte-like?cell?occupied?a?large?portion?of?the?cell.?Cytoskeleton?was?arranged?dendritically?on?the?surface.?Pseudopodia?were?extended?from?cell?edges.?The?spindle-shapednucleus?of?the?fibroblast-like?cell?occupied?a?significantly?larger?region?compared?with?the?cytoplasmic?region.?Cytoskeleton?was?arranged?regularly.?Cell?edges?were?smooth?with?less?pseudopodia?extended.?No?difference?was?found?in?the?surface?roughness?between?the?two?types?of?cells.?According?to?the?force-versus-distance?curves,?the?Young’s?moduli?of?the?two?types?of?cells?were?not?statistically?different?(P>0.05),?but?differences?were?found?in?the?cytoplasmic?regions?(P=0.047).?No?statistical?difference?was?found?in?the?adhesions?between?the?two?types?of?cells?(P>0.05).?Conclusion??The?AFM?topography?and?curves?were?compared?and?analyzed.?The?two?types?of?TMJ?disc?cells?exhibited?significantly?different?topographies,?but?only?slight?difference?in?their?mechanical?abilities.

BACKGROUND:Our preliminary studies have shown that basic fibroblast growth factor can induce the differentiation of bone marrow mesenchymal stem cells into disc cells of the temporomandibular joint, and for basic fibroblast growth factor, 10μg/L is superior to 5μg/L in col agen synthesis.
OBJECTIVE:To observe ultrastructural changes of bone marrow mesenchymal stem cells after being induced by different concentrations of basic fibroblast growth factor.
METHODS:We cultured primary sheep bone marrow mesenchymal stem cells and selected passage 3 and 4 cells at good growth state. Bone marrow mesenchymal stem cells were stimulated with 5 and 10μg/L basic fibroblast growth factor and their growth state was observed under inverted phase contrast microscope. Uninduced cells served as controls. The slides with cellcrawling pieces were stained with Safranin O, picrosirius and type I col agen immunohistochemistry at days 7, 14 and 21, respectively. Simultaneously we col ected the cells at day 21 to observe the ultrastructural changes of bone marrow mesenchymal stem cells.
RESULTS AND CONCLUSION:After being induced with different concentrations of basic fibroblast growth factor, bone marrow mesenchymal stem cells were able to differentiate into disc cells of the temporomandibular joint;and after being induced with 10μg/L basic fibroblast growth factor, cells were more like fibroblast-like cells of the temporomandibular joint disc. These findings indicate that bone marrow mesenchymal stem cells have morphological basis for differentiation to the fibroblast-like cells of the temporomandibular joint disc.

The present paper is aimed to observe the effects of basic fibroblast growth factor (bFGF) on bone marrow mesenchymal stem cell (BMSCs) differentiation. The bFGF was used to stimulate BMSCs and histology, immunohistochemistry and enzyme linked immunosorbent assay (ELISA) were used to examine the extracellular matrix produced by induced BMSCs, evaluated the feasibility of BMSCs being the seeding cells of temporomandibular joint (TMJ) disc tissue engineering. The results showed that having been induced with bFGF, the BMSCs could differentiate into fibroblast-like cells, which could synthesize GAG and collagen type I matrix. So it is feasible for BMSCs as seeding cells for engineered TMJ disc.
Animals ; Bone Marrow Cells ; cytology ; Cell Differentiation ; drug effects ; Cells, Cultured ; Collagen Type I ; biosynthesis ; Fibroblast Growth Factor 2 ; pharmacology ; Glycosaminoglycans ; biosynthesis ; Goats ; Mesenchymal Stromal Cells ; cytology ; metabolism ; Temporomandibular Joint Disc ; cytology ; Tissue Engineering

Caries is a chronicly infectious disease which happens to the hard tissue of the teeth and is the most common dental disease of human. Many scholars have devoted to research anticarigenics drugs and the Chinese herbal was considerably concerned. The paper briefly introduces kinds of anticarigenics Chinese herbals, such as Turkish galls, TFA and Magnolia.
Dental Caries ; drug therapy ; prevention & control ; Drugs, Chinese Herbal ; therapeutic use ; Humans ; Medicine, Chinese Traditional

Objective:To study the isolation, culture and identification of the TMJ cells and to observe the biological characteristics of cultured fibrochondrocytes. Methods:The TMJ discs were dissected from two 1 month goats under sterile conditions and were digested with collagenase. The cells were collected. Morphological changes and attachment efficiency were constantly observed under phase-contrast microscope. Immunohistochemical staining for type I collagen as well as toluidine blue staining were performed. Ultrastructures of the TMJ cells were observed under transmission electron microscope. Results: Most of the primary fibrochondrocytes presented a short spindle-shape while the rest showed polygon-shape. On the 7th day, the perliferating fibrochondrocytes started to contact each other to form a monolayer covering the bottom of the incubation disc. Immunohistochemical staining of type I and toluidine blue staining exhibited positive results. The fibrochondrocytes cytoplasms were rich in mictochondria and endoplasm reticulum. Conclusion: The fibrochondrcytes isolated from one-month-old goat TMJ disc have good proliferation ability in vitro and cells from passage 1 to 3 might be used as seed cells for TMJ disc tissue engineering.