Runx2 overexpression promotes bone repair of osteonecrosis of the femoral head (ONFH).

BACKGROUND: Runt-related transcription factor-2 (Runx2) has been considered an inducer to improve bone repair ability of mesenchymal stem cells (MSCs). METHODS AND RESULTS: Twenty-four rabbits were used to establish Osteonecrosis of the femoral head (ONFH) and randomly devided into four groups: Adenovirus Runx2 (Ad-Runx2) group, Runx2-siRNA group, MSCs group and Model group. At 1 week after model establishment, the Ad-Runx2 group was treated with 5 × 107 MSCs transfected through Ad-Runx2, the Runx2-siRNA group was treated with 5 × 107 MSCs transfected through Runx2-siRNA, the MSCs group was injected with 5 × 107 untreated MSCs, and the Model group was treated with saline. The injection was administered at 1 week and 3 weeks after model establishment. The expression of bone morphogenetic protein 2 (BMP-2), Runx2 and Osterix from the femoral head was detected at 3 and 6 weeks after MSCs being injected, and Masson Trichrome Staining, Gross Morphology, X-ray and CT images observation were used to evaluate the repair effect of ONFH. The data revealed that the expression of BMP-2, Runx2 and Osterix in the Runx2-siRNA group was reduced at 3 weeks compared with the MSCs group, and then the expression further reduced at 6 weeks, but was still higher than the Model group besides Osterix; The expression of these three genes in the Ad-Runx2 group was higher than in the MSCs group. Masson Trichrome Staining, Gross Morphology and X-ray and CT images observation revealed that necrotic femoral head of the MSCs group was more regular and smooth than the Runx2-siRNA group, which has a collapsed and irregular femoral head. In the Ad-Runx2 group, necrotic femoral head was basically completely repaired and covered by rich cartilage and bone tissue. CONCLUSIONS: Overexpression of Runx2 can improve osteoblastic phenotype maintenance of MSCs and promote necrotic bone repair of ONFH.

Epitome of China's unnatural deaths: a historically retrospective study of forensic autopsy cases in Shanghai Public Security Bureau from 1990 to 1999.

The unnatural death investigation in China seems vague to the world. Shanghai is one of the largest city located in Yangtze River Delta in the East China. This study is committed to lift the veil of unnatural death investigation and describe the epitome of China's unnatural deaths. Based on the 7302 forensic report archives from 1990 to 1999 in Shanghai Public Security Bureau, statistics were carried out in 5 areas according to the manner of death. In 3502 accidental deaths, there was a rapid increase during the 1990s, and 71.6% were involved in traffic accidents whose major cause of death was head and neck injuries. The first 3 causes of death in nontraffic accidents (994) were head and neck injuries (42.8%), poisoning (11.8%), and drowning (9.0%). In 2456 homicides, sharp force injury (36.7%), blunt force injury (35.8%), and manual strangulation (12.9%) were the first 3 causes of death. In 563 suicides, drug/chemical intoxication (40.1%), hanging (23.4%), and injuries because of fall from height (11.4%) were the 3 leading causes of death, especially pesticides ingestion. The causes of natural deaths were diseases mainly in circulatory system (23.1%), central nervous system (12.8%), and respiratory system (6.4%). However, the cause of death remained undetermined in 500 victims. Childhood fatalities were different. The victims of accidents and homicides were nearly equal, and the main cause of homicide was manual strangulation. Besides, 1997 was the landmark year when drug abuse began to emerge in Shanghai.

Single-cell transcriptomic landscape of the sheep rumen provides insights into physiological programming development and adaptation of digestive strategies.

As an important evolutionary innovation and unique organ, the rumen has played a crucial role in ruminant adaptation to complex ecological environments. However, the cellular basis of its complex morphology and function remains largely unknown. In this study, we identified eight major cell types from seven representative prenatal and postnatal rumen samples using ~56 600 single-cell transcriptomes. We captured the dynamic changes and high heterogeneity in cellular and molecular profiles before, during, and after the appearance of keratinized stratified squamous epithelium with neatly arranged papillae and functional maturity. Basal cells, keratinocytes, differentiating keratinocytes, terminally differentiated keratinocytes, and special spinous cells provided the cellular basis for rumen epithelium formation. Notably, we obtained clear evidence of two keratinization processes involved in early papillogenesis and papillae keratinization and identified TBX3 as a potential marker gene. Importantly, enriched stratum spinosum cells played crucial roles in volatile fatty acid (VFA) metabolism and immune response. Our results provide a comprehensive transcriptional landscape of rumen development at single-cell resolution, as well as valuable insight into the interactions between dietary metabolism and the rumen.

Exosomes Derived from Runx2-Overexpressing BMSCs Enhance Cartilage Tissue Regeneration and Prevent Osteoarthritis of the Knee in a Rabbit Model.

Objectives: Osteoarthritis is the leading disease of joints worldwide. Osteoarthritis may be treated by exosomes derived from Runx2-overexpressed bone marrow mesenchymal stem cells (R-BMSCs-Exos). R-BMSCs-Exos would promote the proliferation, migration, and phenotypic maintenance of articular chondrocytes. Methods: BMSCs were transfected with and without Runx2. Exosomes derived from BMSCs and R-BMSCs (BMSCs-Exos and R-BMSCs-Exos) were isolated and identified. Proliferation, migration, and phenotypic maintenance were determined in vitro and compared between groups. The mechanism for activation of Yes-associated protein (YAP) was investigated using small interfering RNA (siRNA). The exosomes' preventive role was determined in vivo using Masson trichrome and immunohistochemical staining. Results: R-BMSCs-Exos enhance the proliferation, migration, and phenotypic maintenance of articular chondrocytes based on the YAP being activated. R-BMSCs-Exos prevent knee osteoarthritis as studied in vivo through a rabbit model. Conclusions: Findings emphasize the efficacy of R-BMSCs-Exos in preventing osteoarthritis. Potential source of exosomes is sorted out for the advantages and shortcomings. The exosomes are then modified based on the molecular mechanisms to address their limitations. Such exosomes derived from modified cells have the role in future therapeutics.

[Analysis of 54 mental disability reappraisal cases due to brain damage].

OBJECTIVE: To investigate the different kinds of controversial cases of mental disability after brain damage, to analysis the problems in the first appraisal, and to explore solutions of the problems. METHODS: The reappraisals of mental disorders after traumatic brain damage were collected from 2007-2011 in Shanghai forensic center, and the first appraisal and reappraisal cases were analyzed and compared. RESULTS: The changes of conclusion in reappraisal cases showed the following major reasons: inappropriate appraisal time, not comprehensive and object investigation of mental state of patients in first appraisal, misunderstanding the standards, etc. CONCLUSION: The quality improvement of appraisal should adopt the following measures: regulating the practice, improvement of the professional skills of experts, choosing appropriate appraisal time, improvement of appraisal standards, etc.

Predicting the morbidity of chronic obstructive pulmonary disease based on multiple locally weighted linear regression model with K-means clustering.

Chronic Obstructive Pulmonary Disease (COPD) is a common chronic respiratory disease related to inflammation affected by harmful gas and particulate matter in the air. Mathematical prediction models between COPD and air pollutants are helpful for early identification, individualized interventions to slow disease progression, and for reduction of medical expenditures. The aim was to build a regression prediction model for the occurrence of COPD acute exacerbation. We collected hospital admissions for COPD in 2015-2018 from ten hospitals in Chongqing, China, used the increment per week as response, and the local sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO) and particulate matter 2.5 (PM2.5) concentrations as predictor variables to build a multiple prediction model. The Mean Absolute Percentage Error (MAPE) was used to evaluate the efficiency. We found that PM2.5 and SO2 are the most important factors contributing to the improvement of prediction accuracy. Multiple locally weighted linear regression (LWLR) Model based on integrated kernel framework with the K-means algorithm demonstrated minimum prediction error of 9.03 %(k=11).

Overexpressing Runx2 of BMSCs Improves the Repairment of knee Cartilage Defects.

BACKGROUND: Recruitment of gene modifying bone marrow mesenchymal stem cells (BMSCs) has been considered an alternative to single-cell injection in articular cartilage repair. PURPOSE: This study aimed to investigate whether the effect of runt-related transcription factor 2(Runx2) overexpression bone marrow mesenchymal stem cells in vivo could improve the quality of repaired tissue of a knee cartilage defect in a rabbit model. METHODS: Thirty-two New Zealand rabbits were randomly divided into four groups. The blank group (Con) did not receive anything, the model group (Mo) was administered saline, the simple stem cell group (MSCs) received MSCs injection, and the Runx2 transfection group (R-MSCs) received Runx2 overexpression MSCs injection. After adapting to the environment for a week, a 5 mm diameter cylindrical osteochondral defect was created in the center of the medial femoral condyle. Cell and saline injections were performed in the first and third weeks after surgery. The cartilage repair was evaluated by macroscopically and microscopically at 4 and 8 weeks. RESULTS: Macroscopically, defects were filled and surfaces were smoother in the MSCs groups than in the Mo group at 4th week. Microscopically, the R-MSCs group showed coloration similar to surrounding normal articular cartilage tissue at 8 weeks in masson trichrome staining. The COL-II, SOX9, and Aggrecan mRNA expressions of MSCs were enhanced at 4 weeks compared with R-MSCs, then the expression reduced at 8 weeks, but was still higher than Mo group level (P<0.05). The western blot examination revealed that the COL-IIand SOX9 expression of MSCs was higher than R-MSCs at 4 weeks, then the expression reduced at 8 weeks, but was still higher than the Mo level (P<0.05). The IL-1ß content in the joint fluid also revealed that cartilage repair with R-MSCs was better than that with MSCs at 8 weeks (P<0.05). CONCLUSION: The R-MSCs group showed cellular morphology and arrangement similar to surrounding normal articular cartilage tissue, and Runx2 overexpression of MSCs resulted in overall superior cartilage repair as compared with MSCs at 8 weeks.

[Vascularized pedicle iliac crest for the repair of bone and soft tissue defect of lower extremity].

OBJECTIVE: To study the role of transplantation of the vascularized pedicle iliac crest for the repair of bone and soft tissue defect of lower extremity. METHODS: The vascularized pedicle iliac crest was designed for the repair of bone and soft tissue defect of lower extremity according to anatomic feature of leg and foot. Skin graft was used for coverage of the iliac flap. RESULTS: Skin survival could demonstrate the survival of the vascularized pedicle iliac crest indirectly one week postoperatively. Skin survived completely in 4 cases and partly in 3 cases. Callus was seen at the transplantation site one month postoperatively, and K-wires were removed 4 months later in the cases of metatarsal defect. The external fixators were removed in the cases of tibia defect 6 to 8 months postoperatively. The functions of lower extremities were restored in 2 to 4 months. The bone and soft tissue defects were repaired, and ultimate function and cosmetic effects were satisfied after the mean follow up of 10 months (ranged from 6 to 15 months). CONCLUSION: Transplantation of the vascularized pedicle iliac crest is an ideal method for the repair of bone and soft tissue defect of lower extremity. The operation can be performed in one stage. The functions and cosmetic effects are better than the traditional methods.

[Construction of eucaryotic expression plasmid carrying the BMP7 gene and expression in mesenchymal stem cells].

OBJECTIVES: To construct an eucaryotic expression plasmid carrying the BMP7 gene and express in MSCs. METHODS: The BMP7 gene was cloned into the eucaryotic expression vector pcDNA3.1. At the same time, mesenchymal stem cells (MSCs) were isolated and cultured in vitro. The plasmid carrying the BMP7 gene was transfected into MSCs. RESULTS: PCR and digesting demonstrated that the eucaryotic expression plasmid -pcDNA-BMP7 was obtained. RT-PCR and immunohistochemical methods showed that the BMP7 gene was expressed in MSCs. CONCLUSION: Construction of an eucaryotic expression plasmid carrying BMP7 gene and expression in MSCs provide a sound basis for gene therapy using the BMP7 gene and the ideal seeds for tissue engineering.

[Experimental study of the isolation, culture and in chondrogenic differentiation of human bone mesenchymal stem cell].

OBJECTIVE: To study the isolation of human bone marrow mesenchymal stem cells (MSCs) and in vitro differentiation into chondrocytes as potential seed cell for condyle cartilage tissue engineering. METHODS: Human MSCs were isolated by percoll solution from normal human bone marrow sample and cultured in flasks. Specific cell surface markers were identified by flow-cytometry. After the cells were treated with inductive medium containing insulin, transferrin, pyruvate, dexathemesone and TGF-beta for 7 - 14 days, microscopic, histological and immuno-histo-chemical studies were performed for chondrogenic phenotype identification. RESULTS: Primary cultures of human MSCs express CD29 and CD44 positively and meanly, but CD34, CD45 and HLA-DR negatively. After 14 days of induction, the cells were positively stained by safranin O. Immunohistochemical analysis proved strong type II collagen expression. CONCLUSIONS: Percoll helps to generate a better isolation of MSCs from human bone marrow aspirates with a purity more above 95%. The isolated MSCs can be expanded and induced in vitro to differentiate into chondrocytes by inductive medium.