Hepatocyte growth factor enhances the ability of dental pulp stem cells to ameliorate atherosclerosis in apolipoprotein E-knockout mice.

BACKGROUND: Atherosclerosis (AS), a chronic inflammatory disease of blood vessels, is a major contributor to cardiovascular disease. Dental pulp stem cells (DPSCs) are capable of exerting immunomodulatory and anti-inflammatory effects by secreting cytokines and exosomes and are widely used to treat autoimmune and inflammation-related diseases. Hepatocyte growth factor (HGF) is a pleiotropic cytokine that plays a key role in many inflammatory and autoimmune diseases. AIM: To modify DPSCs with HGF (DPSC-HGF) and evaluate the therapeutic effect of DPSC-HGF on AS using an apolipoprotein E-knockout (ApoE-/-) mouse model and an in vitro cellular model. METHODS: ApoE-/- mice were fed with a high-fat diet (HFD) for 12 wk and injected with DPSC-HGF or Ad-Null modified DPSCs (DPSC-Null) through tail vein at weeks 4, 7, and 11, respectively, and the therapeutic efficacy and mechanisms were analyzed by histopathology, flow cytometry, lipid and glucose measurements, real-time reverse transcription polymerase chain reaction (RT-PCR), and enzyme-linked immunosorbent assay at the different time points of the experiment. An in vitro inflammatory cell model was established by using RAW264.7 cells and human aortic endothelial cells (HAOECs), and indirect co-cultured with supernatant of DPSC-Null (DPSC-Null-CM) or DPSC-HGF-CM, and the effect and mechanisms were analyzed by flow cytometry, RT-PCR and western blot. Nuclear factor-κB (NF-κB) activators and inhibitors were also used to validate the related signaling pathways. RESULTS: DPSC-Null and DPSC-HGF treatments decreased the area of atherosclerotic plaques and reduced the expression of inflammatory factors, and the percentage of macrophages in the aorta, and DPSC-HGF treatment had more pronounced effects. DPSCs treatment had no effect on serum lipoprotein levels. The FACS results showed that DPSCs treatment reduced the percentages of monocytes, neutrophils, and M1 macrophages in the peripheral blood and spleen. DPSC-Null-CM and DPSC-HGF-CM reduced adhesion molecule expression in tumor necrosis factor-α stimulated HAOECs and regulated M1 polarization and inflammatory factor expression in lipopolysaccharide-induced RAW264.7 cells by inhibiting the NF-κB signaling pathway. CONCLUSION: This study suggested that DPSC-HGF could more effectively ameliorate AS in ApoE-/- mice on a HFD, and could be of greater value in stem cell-based treatments for AS.

Inactivation of Pseudomonas aeruginosa biofilms by thymoquinone in combination with nisin.

Pseudomonas aeruginosa is one of the most important foodborne pathogens that can persist in leafy green vegetables and subsequently produce biofilms. In this study, the synergistic effect of thymoquinone and nisin in reducing biofilm formation of P. aeruginosa on lettuce was evaluated, and their anti-virulence and anti-biofilm mechanisms were also investigated. At concentrations ranging from 0.5 to 2 mg/ml, thymoquinone inhibited the production of autoinducers and virulence factors, and enhanced the susceptibility of P. aeruginosa biofilms to nisin as evidenced by the scanning electron microscopy and confocal laser scanning microscopy. Integrated transcriptomics, metabolomics, and docking analyses indicated that thymoquinone treatment disrupted the quorum sensing (QS) system, altered cell membrane component, and down-regulated the expressions of genes related to virulence, efflux pump, and antioxidation. The changed membrane component and repressed efflux pump system enhanced membrane permeability and facilitated the entrance of nisin into cells, thus improving the susceptibility of biofilms to nisin. The dysfunctional QS and repressed antioxidant enzymes lead to the enhancement of oxidative stress. The enhanced oxidative stress disrupted energy metabolism and protein metabolism and ultimately attenuated the virulence and pathogenicity of P. aeruginosa PAO1. Our study indicated that thymoquinone has the potential to function as a QS-based agent to defend against foodborne pathogens in combination with nisin.

Micrometer-Sized Titanium Particles Induce Aseptic Loosening in Rabbit Knee.

Wear debris induced aseptic loosening is the leading cause of total knee arthroplasty (TKA) failure. The complex mechanism of aseptic loosening has been a major issue for introducing effective prevention and treatment methods, so a simplified yet efficient rabbit model was established to address this concern with the use of micrometer-sized titanium particles. 20 New Zealand white rabbits were selected and divided into two groups (control = 10, study = 10). A TKA surgery was then performed for each of them, with implantation of a titanium rod prosthesis which was coated evenly with micrometer-sized titanium in the study group and nothing in the control group, into right femoral medullary cavity. After 12 weeks, all the animals were euthanized and X-ray analyses, H&E staining, Goldner Masson trichrome staining, Von Kossa staining, PCR, and Western blotting of some specific mRNAs and proteins in the interface membrane tissues around the prosthesis were carried out. The implantation of a titanium rod prosthesis coated with 20 µm titanium particles into the femoral medullary cavity of rabbits caused continuous titanium particle stimulation around the prosthesis, effectively inducing osteolysis and aseptic loosening. Titanium particle-induced macrophages produce multiple inflammatory factors able to activate osteoclast differentiation through the OPG/RANKL/RANK signaling pathway, resulting in osteolysis while suppressing the function of osteoblasts and reducing bone ingrowth around the prosthesis. This model simulated the implantation and loosening process of an artificial prosthesis, which is an ideal etiological model to study the aseptic prosthetic loosening.

Astragaloside IV suppresses inflammatory mediator production in synoviocytes and collagen­induced arthritic rats.

The aim of the current study was to investigate the effects of Astragaloside­IV (AS­IV) on inflammatory mediators in synoviocytes and collagen­induced arthritic rats. Synoviocytes were stimulated with lipopolysaccharides (LPS) and Sprague­Dawley rats were injected with type II collagen. AS­IV was administered to the LPS­stimulated synoviocytes and collagen­induced arthritis (CIA) rats. The inflammation of LPS­stimulated synoviocytes and CIA rats was assessed using enzyme­linked immunosorbent assays and western blotting. Using Cell Counting Kit­8 analysis, it was demonstrated that AS­IV (5, 20 and 50 mg/ml) inhibited the LPS­stimulated synoviocytes proliferation in a dose­dependent manner. AS­IV significantly inhibited the LPS­stimulated inflammatory response, as indicated by the expression levels of TNF­α, IL­1ß, IL­6 and IL­8. In addition, treatment with AS­IV significantly reduced the LPS­stimulated cyclooxygenase (COX)­1, COX­2, high mobility group box 1 protein (HMGB1) and intercellular adhesion molecule 1 overexpression, and intranuclear nuclear factor (NF)­κBp65 subunit accumulation and activation of c­Jun N­terminal kinase (JNK)1/2 and p38. Similar to the protective effects of AS­IV on LPS­stimulated synoviocytes, AS­IV treatment significantly reduced the expression levels of tumor necrosis factor α, interleukin (IL)­1ß, IL­6 and IL­8 expression levels, and attenuated intranuclear NF­κBp65 subunit accumulation and overexpression of COX­2 and inducible nitric oxide synthase in CIA rats. In conclusion, the results of the present study demonstrated for the first time, to the best of our knowledge, that AS­IV protects synoviocytes against LPS­ and collagen­induced inflammatory responses through inhibition of the HMGB1­dependent JNK1/2­ and p38­activated NF­κB/COX­2 pathway.

Crop Classification Based on Time Series MODIS EVI and Ground Observation for Three Adjoining Years in Xinjiang.

There is a regular use of Moderate Resolution Imaging Spectroradiometer (MODIS) 250 meter EVI to classify the crops on a regional level throughout the world. A rapid agricultural land use change attributed to new Chinese agriculture policy is attracting many researchers to focus. The objective of this study is to present a more straightforward multiyear classification methodology using time series MODIS EVI with 250 meters spatial resolution and subsequent field data in Xinjiang, China. An extensive polygon based ground reference annual crop data were collected for the years 2011, 2012 and 2013 throughout the study area. The most pure pixel within each polygon was selected which eases crop differentiation. Artificial Immune Network (ABNet) was used to classify cotton, maize, wheat/others, rice and grapes, dominating most of the study area. The data of two different years were used together to classify the crop of next year, as 2011 and 2012 were used to classify crops of 2013. Classification results were validated using the same year ground data. Results showed the classification accuracy above 80% for each year with kappa coefficient of 0. 7 and above. However more research and additional ground reference data are needed to classify a range of crops in the study area which will give a more detailed view of the land use land cover change strengthening agriculture decisions practices in the future.

[Repair full-thickness meniscal defects with injectable tissue engineering technique].

OBJECTIVE: To investigate the effectiveness of injectable tissue engineering to repair full-thickness meniscal defects. METHODS: From June 2008 to February 2009 full-thickness of meniscal defects were created in the anterior corner of goats, which with no blood supply, in a diameter of 2 mm. Then bone marrow stem cells (BMSCs) was mixed with injectable calcium alginate gel to fill the defects. Other groups include the calcium alginate gel and empty group were served as control groups. At different time points, the animals were sacrificed and macroscopy, microscopy determination, electroscopy and MRI detection were performed to assess the outcomes of repairing. RESULTS: The meniscal defects had been filled thoroughly in 16 weeks after operation with white, tough and elastic repair tissue similar to normal meniscal fibrocartilage in the tissue engineering groups. The repair tissue was mainly fibrochondrocytes in line with the calcium alginate fiber. Thick matrix secreted by the cells crammed the space between fibers. The view under electroscopy demonstrated that the microstructure of the repair tissue was normal and cells were in a fibrocartilage phenotype. CONCLUSION: The full-thickness meniscal defects in regions without blood supply can be reconstructed effectively with injectable tissue engineering.

[The efficacy of open-wedge high tibial osteotomy for varus knee].

OBJECTIVE: To introduce the biplanar opening high tibial osteotomy with rigid fixation for adult varus knee. METHODS: Twelve patients with varus knee and degeneration of medial compartment received the biplanar opening high tibial osteotomy between June 2001 and July 2008. The pre-operative deformity was about 11.5 degrees without osteoarthritis changes in other compartments. The average range of motion was more than 90 degrees . One of the patients had ruptures of LCL and ACL, who received osteotomy after reconstruction of the ligaments. The main symptom before the operation was pain in medial compartment. The range of motion, Lysholm score and subjective satisfactory examinations were assessed before and after the osteotomy. RESULTS: All of the osteotomy sites were healed at twelve to sixteen weeks after operation. No complications such as plate broken or injury of nerve or blood vessel had occurred. The mean correct angle was 9.5 degrees . No degenerative changes had developed in other compartments of the knee. The mechanical axis of the lower extremities was maintained during the follow-up. The overall satisfactory rate was 83.3%. Statistically significant changes exist in the Lysholm score and varus degree. CONCLUSION: The open-wedge high tibial osteotomy is suitable for the symptomatic genu varum in younger patients with good short-term and mid-term results.

Modified biplanar open-wedge high tibial osteotomy with rigid locking plate to treat varus knee.

OBJECTIVE: To introduce and characterize the modified biplanar opening high tibial osteotomy with rigid fixation to treat varus knee in young and active patients. METHODS: Between June 2001 to July 2008, 18 patients with monocompartmental degeneration of the knee combined with a varus malalignment of the leg had the modified biplanar opening high tibial osteotomy and the osteotomy was fixed with the locking plates (Locking Compression Plate System). The mean varus deformity before operation was 11.5 degrees (5 degrees approximately 19 degrees ) and no degenerative changes were found in other departments. Stability of the knee was normal in 15 patients, but ruptures in anterior cruciate ligaments or lateral collateral ligament were presented in the remaining 3 patients. Preoperative symptom was mainly limited in the pain of medial compartment. The preoperative and follow-up data for the range of motion and Lysholm score were determined. Subjective satisfactory examination was also applied to the patients for the operation they selected. RESULTS: All of the patients were followed up with an average of 32.5 months (12 approximately 82 months). There was no ununion or delayed union in this group during the follow-up period. No complications like broken plate, nerve injury, or blood vessel injury occurred. The postoperative average corrected degree was 9.5 degrees (5.5 degrees approximately18 degrees ). No degenerations developed in the three departments of the knee. The Lysholm scores before and after surgery were 42.5 and 77.5, respectively (P<0.01). The overall fineness rate was 83.3%. The subjective satisfactory survey demonstrated that about 83.3% patients showed satisfactory on the operation. There was no obvious difference in the range of motion before and after operation, but significant changes were found in the Lysholm score and varus degree from preoperative to follow-up. CONCLUSION: Proximal opening high tibial osteotomy performed in conjunction with the special rigid locking plate yielded good results for symptomatic genu varum. This new classic technique can be effectively applied to the medial compartment degeneration of the knee in active young patients.