Rac1 promotes the formation of heterotypic cell-in-cell structure / 生物工程学报

Heterotypic cell-in-cell structures (heCICs) are closely related to tumor development and progression, and have become a new frontier in life science research. Ras-related C3 botulinum toxin substrate 1 (Rac1) belongs to the classic Rho GTPase, which plays a key role in regulating the cytoskeleton and cell movement. To investigate the role and mechanism of Rac1 in the formation of heCICs, tumor cells and immune killer cells were labeled with cell-tracker, respectively, to establish the heCICs model. Upon treatment with the Rac1 inhibitor NSC23766, the formation of heCICs between tumor and immune cells was significantly reduced. The plasmid pQCXIP-Rac1-EGFP constructed by gene cloning was packaged into pseudoviruses that subsequently infect tumor cells to make cell lines stably expressing Rac1. As a result, the formation of heCICs was significantly increased upon Rac1 overexpression. These results demonstrated a promotive role of Rac1 in heCICs formation, which may facilitate treating cell-in-cell related diseases, such as tumors, by targeting Rac1.

Research progress on the design of bone scaffolds with different single cell structures / 中国修复重建外科杂志

OBJECTIVE@#To review the research progress of design of bone scaffolds with different single cell structures.@*METHODS@#The related literature on the study of bone scaffolds with different single cell structures at home and abroad in recent years was extensively reviewed, and the research progress was summarized.@*RESULTS@#The single cell structure of bone scaffold can be divided into regular cell structure, irregular cell structure, cell structure designed based on topology optimization theory, and cell structure designed based on triply periodic minimal surface. Different single cell structures have different structural morphology and geometric characteristics, and the selection of single cell structure directly determines the mechanical properties and biological properties of bone scaffold. It is very important to choose a reasonable cell structure for bone scaffold to replace the original bone tissue.@*CONCLUSION@#Bone scaffolds have been widely studied, but there are many kinds of bone scaffolds at present, and the optimization of single cell structure should be considered comprehensively, which is helpful to develop bone scaffolds with excellent performance and provide effective support for bone tissue.

Surface characteristics of pure titanium loaded graphene oxide: effect on bacteria adhesion and osteoblast structure / 华西口腔医学杂志

OBJECTIVE@#To evaluate the process characterization of graphene oxide loaded on pure titanium surface and effect on the biological properties of Staphylococcus aureus and osteoblasts.@*METHODS@#Graphene oxide at four concentrations (20, 50, 80, and 100 µg·mL⁻¹) was loaded on the pure titanium surface via electroplating, and the morphology, properties, and hydrophilic properties were measured with a field emission scanning electron microscope, micro Raman spectrometer, and contact angle tester, respectively. In addition, Staphylococcus aureus and osteoblasts were used as models and cultured with pure titanium-graphene oxide. Then, field-emission scanning electron microscopy and laser confocal microscopy were utilized to observe the changes in the amount of bacteria and osteoblast morphology and structure, respectively.@*RESULTS@#Graphene oxide at the four concentrations was successfully loaded on pure titanium surface via electroplating. It improved the hydrophilic properties of pure titanium surface, which benefitted the adhesion and growth of Staphylococcus aureus and changed the morphology and structure of the osteoblasts.@*CONCLUSIONS@#The pure titanium-graphene oxide composite has no antibacterial properties and has good biocompatibility.

Ultrastructure of periosteal cells induced by bone morphogenetic protein 7 in vitro / 中国组织工程研究

BACKGROUND:Study confirms that bone morphogenetic protein can induce osteogenesis;however the ultrastructure of periosteal cells induced by bone morphogenetic protein-7 remains poorly reported. OBJECTIVE:To study the bioactivity and ultrastructure of periosteal cells induced by bone morphogenetic protein-7 in vitro. METHODS:The primary periosteal cells isolated from adult tibial bone were in vitro cultured, and then divided into experimental group and control group. In the experimental group, cells were cultured with bone morphogenetic protein-7 and culture adjuvant;while cells in the control group were only cultured with the adjuvant. Three samples in each group were tested at 5, 10, 15 days, respectively. The general structure of cultured cells was observed using von Kossa staining, and the ultrastructure was observed under transmission electron microscopy. RESULTS AND CONCLUSION:The periosteal cells in the two groups grew wel in vitro, showing uniform morphology. Early cells were spindle-shaped, with strong three-dimensional sense and ful transparency;mitotic cells were short columnar or cubic shaped, there were a lot of rough endoplasmic reticulum and Golgi complex in osteoblasts under electron microscope. Later stage of cells developed from long fusiform into wide shuttle and irregular shape, there were a large number of matrix vesicles within the cells under the electron microscope. The membrane coating, alkaline phosphatase and calcium-binding protein in the cytoplasm, as wel as calcium crystals were found. The osteogenesis basement and lateral sides appeared projections, which were connected with adjacent bone cells. Induction of bone morphogenetic protein-7 in vitro promotes the osteoblasts proliferation, division and bone formation speed. The results suggest that bone morphogenetic protein-7 can significantly enhance the proliferation ability of osteoblasts in vitro.

Aproximación a aa estructura tridimensional de a desmina bovina y determinacióón del efecto de mutaciones puntuales in-silico / Aproach to tridiimensional structue of bovine desmin and in-silicco determination of punctual mutationseeffect

La desmina es el mayor filamento proteico intermedio del miocito y desempeña un papel importante respecto de las características de calidad cárnica, dada su función intracelular de sostén y que es sustrato de los principales sistemas proteolíticos post-mortem. En la determinación de los parámetros fisicoquímicos de dicha proteína y de su ARNm, se consideraron siete mutaciones (polimorfismos de nucleótido simple, SNP) en bovino y cinco en porcino ubicadas en regiones exónicas. Mediante procedimientos computacionales se obtuvo un modelo tridimensional que incluyó desde el aminoácido 39 al 470 de la secuencia DAA32384.1. Se identificó que las mutaciones T49C y A45C del ARNm del bovino son responsables de una modificación en la estructura bidimensional del ARNm y de la disminución de su estabilidad in-silico, por lo que se les considera como las mutaciones más significativas para evaluar experimentalmente en bovinos.

Desmin is the major proteic intermediate filament protein of muscular cell and it has an important effect on meat quality features because this protein is structural and during post-mortem conversion is substrate of proteolysis systems. Seven functional SNP (Single Nucleotide Polymorphisms) of bovine and five of porcine were evaluated in several physicochemical features of the molecules RNAm and protein of Desmin. A 3D model was obtained from aminoacid 39 to 470 of the sequence DAA32384.1. Mutations T49C and A45C of bovine RNAm modify the molecular structure and these have less in-silico stability. On this way, these should be tested to experimental level.