Long non-coding RNA MIR22HG suppresses the chondrogenic differentiation of human adipose-derived stem cells by interacting with CTCF to upregulate CRLF1.

Improved chondrogenic differentiation of mesenchymal stem cells (MSCs) by genetic regulation is a potential method for regenerating articular cartilage. LncRNA MIR22HG has been proven to accelerate osteogenic differentiation, but the regulation mechanism of chondrogenic differentiation is still unclear. Human adipose-derived stem cells (hADSCs) have been widely utilised for bone tissue engineering applications. The present study aimed to examine the effect of MIR22HG on the chondrogenic differentiation of hADSCs. The results confirmed that MIR22HG was downregulated in the process of chondrogenic differentiation. Subsequently, gain- and loss-of-function of MIR22HG experiments showed that the overexpression of MIR22HG suppressed the deposition of cartilage matrix proteoglycans and decreased the expression of cartilage-related markers (e.g. Sox9, ACAN and Col2A1), whereas the knockdown of MIR22HG had the opposite effect. MIR22HG could bind to CTCF (CCCTC-binding factor), and CTCF could bind to the CRLF1 (cytokine receptor-like factor 1) promoter and upregulate CRLF1 gene expression. Besides, inhibition of CRLF1 can reverse the effect of MIR22HG on cell chondrogenic differentiation of hADSCs. Taken together, our outcomes reveal that MIR22HG suppressed chondrogenic differentiation by interaction with CTCF to stabilise CRLF1.

Clinical effects of 3D printing-assisted posterolateral incision in the treatment of ankle fractures involving the posterior malleolus.

Objective: To explore the clinical outcomes of a 3D printing-assisted posterolateral approach for the treatment of ankle fractures involving the posterior malleolus. Methods: A total of 51 patients with ankle fractures involving the posterior malleolus admitted to our hospital from January 2018 to December 2019 were selected. The patients were divided into 3D printing group (28 cases) and control group (23 cases). 3D printing was performed for ankle fractures, followed by printing of a solid model and simulation of the operation on the 3D model. The operation was then performed according to the preoperative plan, including open reduction and internal fixation via the posterolateral approach with the patient in the prone position. Routine x-ray and CT examinations of the ankle joint were performed, and ankle function was evaluated using the American Foot and Ankle Surgery Association (AOFAS) ankle-hindfoot score. Results: All patients underwent x-ray and CT examinations. All fractures healed clinically, without loss of reduction or failure of internal fixation. Good clinical effects were achieved in both groups of patients. The operation time, intraoperative blood loss and intraoperative fluoroscopy frequency in the 3D printing group were significantly less than those in the control group (p < 0.05). There was no significant difference between the two groups in the anatomical reduction rate of fractures or the incidence of surgical complications (p > 0.05). Conclusion: The 3D printing-assisted posterolateral approach is effective in the treatment of ankle fractures involving the posterior malleolus. The approach can be well planned before the operation, is simple to perform, yields good fracture reduction and fixation, and has good prospects for clinical application.

TNF-α activates RELA expression via TNFRSF1B to upregulate OPA1 expression and inhibit chondrogenic differentiation of human adipose stem cells.

BACKGROUND: Tumor necrosis factor-alpha (TNF-α), one of the pro-inflammatory cytokines mediating the local inflammatory process in joints, inhibits cartilage formation and has a detrimental effect on stem cell-based cartilage regeneration for the treatment of osteoarthritis (OA). However, the mechanisms behind this inhibitory effect are still poorly understood. Mitochondrial morphological changes mediated by mitochondrial fusion and fission are highly plastic, are quite sensitive to environmental stimuli and play a crucial role in maintaining cell structure and function. In our study, chondrogenic differentiated human adipose stem cells (hADSCs) were exposed to TNF-α and the effect of TNF-α on the ability of hADSCs to chondrogenic differentiate and on mitochondrial fusion and fission was observed and analyzed. The aim was to investigate the role and mechanisms of mitochondrial fusion and fission regulation in the chondrogenic differentiation of hADSCs under normal conditions and under exposure to TNF-α. METHODS: We used flow cytometry to identify hADSCs immunophenotypes CD29, CD44, CD34, CD45, and HLA-DR. Alcian blue staining and Sirius red staining were used to observe the formation of proteoglycans and collagen during the chondrogenic differentiation of hADSCs, respectively. The mRNA and protein expression levels of the cartilage formation marker SOX9, type II collagen (COL2A1), and Aggrecan were measured by real-time fluorescent quantitative PCR (RT-qPCR) and western blot, respectively. The fluorescent probes MitoTracker® Red CMXRos and JC-1 were used to visualize mitochondria morphology and detect mitochondrial membrane electricity (MMP). Affymetrix PrimeView™ chips were used for gene expression profiling. RESULTS: The results showed that the chondrogenic differentiation of hADSCs was inhibited in the presence of TNF-α that optic atrophy 1 (OPA1) expression was significantly upregulated and mitochondria were prolonged and interconnected during this process. Gene microarray and RT-qPCR data showed that the presence of TNF-α led to increased expression of TNFα receptor 2 (TNFRSF1B) and RELA during chondrogenic differentiation of hADSCs. CONCLUSIONS: TNF-α inhibits chondrogenic differentiation of human adipose stem cells by activating RELA expression through TNFRSF1B upregulating OPA1 expression thereby increasing mitochondrial fusion.

A highly sensitive method for simultaneous detection of hAAG and UDG activity based on multifunctional dsDNA probes mediated exponential rolling circle amplification.

DNA glycosylase is an indispensable DNA damage repair enzyme which can recognize and excise the damaged bases in the DNA base excision-repair pathway. The dysregulation of DNA glycosylase activity will give rise to the dysfunction of base excision-repair and lead to abnormalities and diseases. The simultaneous detection of multiple DNA glycosylases can help to fully understand the normal physiological functions of cells, and determine whether the cells are abnormal in pre-disease. Regrettably, the synchronous detection of functionally similar DNA glycosylases is a great challenge. Herein, we developed a multifunctional dsDNA probe mediated exponential rolling circle amplification (E-RCA) method for the simultaneously sensitive detection of human alkyladenine DNA glycosylase (hAAG) and uracil-DNA glycosylase (UDG). The multifunctional dsDNA probe contains the hypoxanthine sites and the uracil sites which can be recognized by hAAG and UDG respectively to generate apyrimidinic (AP) sites in the dsDNA probe. Then the AP sites will be recognized and cut by endonuclease Ⅳ (Endo IV) to release corresponding single-stranded primer probes. Subsequently, two padlock DNA templates are added to initiate E-RCA to generate multitudinous G-quadruplexes and/or double-stranded dumbbell lock structures, which can combine N-methyl mesoporphyrin IX (NMM) and SYBR Green Ⅰ (SGI) for the generation of respective fluorescent signals. The detection limits are obtained as low as 0.0002 U mL-1 and 0.00001 U mL-1 for hAAG and UDG, respectively. Notably, this method can realize the simultaneous detection of two DNA glycosylases without the use of specially labeled probes. Finally, this method is successfully applied to detect hAAG and UDG activities in the lysates of HeLa cells and Endo1617 cells at single-cell level, and to detect the inhibitors of DNA glycosylases.

Simultaneous detection of diethylstilbestrol and estradiol residues with a single immunochromatographic assay strip.

An immunochromatographic assay (ICA) based on competitive format was developed and validated for simultaneously rapid and sensitive detection of diethylstilbestrol (DES) and estradiol (E2) in milk and tissue samples. For this purpose, two monoclonal antibodies raised against those two estrogens were conjugated to gold nanoparticles and were applied to the conjugate pads of the test strip. The competitors of the DES-BSA/E2-BSA conjugates were immobilized onto a nitrocellulose membrane at two detection zones to form T1 and T2, respectively. The immunochromatographic assay had a visual detection limit of DES at 30 ng/g in milk powder, 25 ng/g in liquid milk, and 25 ng/g in shrimp tissue, respectively, and the results can be judged within 7-10 min. The visual detection limit of E2 was 75 ng/g in milk powder, 65 ng/g in liquid milk, and 60 ng/g in shrimp tissue, respectively, and the results can be judged within 3-4 min. It had advantages in easy operation without requiring sophisticated equipment and specialized skills. By testing thirty milk and shrimp tissue samples from the local market, the method was compared with the HPLC-MS / MS method, and there was no statistical difference between the two methods. Furthermore, the immunochromatographic assay had good specificity, simple procedure, and low cost. This protocol was well suited for the food safety monitoring and early warning.

[Application of one-stage posterior surgery via unilateral musculussacrospinalis iliac flap approach in treatment of lumbosacral tuberculosis].

Objective: To evaluate the safety and effectiveness of one-stage posterior surgery via unilateral musculussacrospinalis iliac flap approach in treatment of lumbosacral tuberculosis. Methods: Between August 2011 and October 2014, 13 patients with lumbosacral tuberculosis were treated by one-stage posterior reserved posterior ligament complex, lesion debridement, bone graft fusion, and internal fixation via unilateral musculussacrospinalis iliac flap approach. There were 8 males and 5 females, aged from 22 to 57 years, with an average age of 35 years. The disease duration ranged from 2 to 19 months, with an average of 6.7 months. According to the American Spinal Injury Association (ASIA) classification criteria, the patients were graded as grade B in 2 cases, grade C in 4 cases, grade D in 5 cases, and grade E in 2 cases before operation. The preoperative Oswestry disability index (ODI) was 36.4±5.7; the preoperative lumbosacral angle was (20.7±0.7)°; the preoperative erythrocyte sedimentation rate (ESR) was (63.4±8.4) mm/1 h; and the preoperative C-reactive protein (CRP) was (38.8±5.2) mmol/L. The operation time and intraoperative blood loss were recorded. The ODI, ASIA grade, lumbosacral angle, and ESR were recorded at last follow-up. Bridwell criterion was used to judge the interbody fusion. Results: The operation time was 150-240 minutes (mean, 190 minutes), and the intraoperative blood loss was 420-850 mL (mean, 610 mL). No major blood vessel, dural sac, nerve root, and lumbosacral plexus injuries occurred during the operation. Delayed wound healing occurred in 3 cases, and primary wound healing achieved in the other patients. No wound infection or sinus formation was found. All 13 patients were followed up 1.5-6.1 years (mean, 2.8 years). During the follow-up period, there was no tubercular symptom, cerebrospinal fluid leakage, loosening and rupture of internal fixator; and no complications such as retrograde ejaculation and erectile dysfunction occurred in 8 male patients. Solid spinal fusion obtained in all patients with the mean fusion time of 6.4 months (range, 4.2-9.9 months); and all iliac osteotomies healed. At last follow-up, the ODI was 7.2±3.5, the lumbosacral angle was (31.2±0.5)°, and ESR was (9.8±2.5) mm/1 h, all of which improved significantly when compared with pre-operative ones ( P<0.05). The patients were classified as grade D in 2 cases and grade E in 11 cases, which improved significantly when compared with preoperative ones ( Z=-3.168, P=0.002). Conclusion: One-stage posterior surgery via unilateral musculussacrospinalis iliac flap approach in treatment of lumbosacral tuberculosis is effective and safe.

Sirtuin 1 Activation Reduces Transforming Growth Factor-ß1-Induced Fibrogenesis and Affords Organ Protection in a Model of Progressive, Experimental Kidney and Associated Cardiac Disease.

Most forms of chronic, progressive kidney disease are characterized by fibrosis whereby the prototypical prosclerotic growth factor, transforming growth factor ß (TGF-ß), is thought to play a pivotal role. With the recent understanding that TGF-ß's canonical signaling pathway may be modified by acetylation as well as phosphorylation, we explored the role of the NAD+-dependent lysine deacetylase, sirtuin 1 (SIRT1) in fibrogenesis in the cell culture, animal model, and human settings. In vitro, the increase in collagen production that results from TGF-ß1 stimulation was ameliorated by the allosteric modifier of Sirt1 deacetylase, SRT3025, in association with a reduction in Smad3 reporter activity. In the remnant kidney model (subtotally or 5/6 nephrectomized rats) that develops progressive kidney disease in association with TGF-ß overexpression, administration of SRT3025 attenuated glomerular filtration rate decline and proteinuria without affecting blood pressure. Glomerulosclerosis and tubulointerstitial fibrosis were similarly reduced with Sirt1 activation as were cardiac structure and function in this rodent model of primary kidney and secondary cardiac disease. Relating these findings to the human setting, we noted a reduction in SIRT1 mRNA in kidney biopsies obtained from individuals with focal glomerulosclerosis. Together these studies highlight the potential of SIRT1 activation as a therapeutic strategy in progressive, fibrotic kidney disease.

Letter regarding Li JS et al. entitled "ERCC polymorphisms and prognosis of patients with osteosarcoma".

With great interest, we read the article "ERCC polymorphisms and prognosis of patients with osteosarcoma" (by Li JS et al.), which has reached important conclusions about the relationship between ERCC polymorphisms and osteosarcoma prognosis. Through quantitative analysis, the meta-analysis showed that ERCC2 Lys751Gln (ORGG vs. AA = 0.40 (95%CI = 0.1-0.86), P heterogeneity = 0.502; I (2) = 0 %) and ERCC5 His46His (ORCC vs. TT = 0.37 (95%CI = 0.15-0.93), P heterogeneity = 0.569; I (2) = 0 %) polymorphisms might influence the prognosis of patients with osteosarcoma [1]. The meta-analysis results are encouraging. Nevertheless, some deficiencies still existed that we would like to raise.