CHRDL2 activates the PI3K/AKT pathway to ameliorate glucocorticoid-induced damages to bone microvascular endothelial cells (BMECs).

Steroid-induced avascular necrosis of the femoral head (ANFH) is characterized by the death of bone tissues, leading to the impairment of normal reparative processes within micro-fractures in the femoral head. Glucocorticoid (GCs)-induced bone microvascular endothelial cell (BMEC) damage has been reported to contribute to ANFH development. In this study, differentially expressed genes (DEGs) between necrosis of the femoral head (NFH) and normal samples were analyzed based on two sets of online expression profiles, GSE74089 and GSE26316. Chordin-like 2 (CHRDL2) was found to be dramatically downregulated in NFH samples. In GCs-stimulated BMECs, cellular damages were observed alongside CHRDL2 down-regulation. GCs-caused cell viability suppression, cell apoptosis promotion, tubule formation suppression, and cell migration suppression were partially abolished by CHRDL2 overexpression but amplified by CHRDL2 knockdown; consistent trends were observed in GCs-caused alterations in the protein levels of VEGFA, VEGFR2, and BMP-9 levels, and the ratios of Bax/Bcl-2 and cleaved-caspase3/Caspase3. GC stimulation significantly inhibited PI3K and Akt phosphorylation in BMECs, whereas the inhibitor effects of GCs on PI3K and Akt phosphorylation were partially attenuated by CHRDL2 overexpression but further amplified by CHRDL2 knockdown. Moreover, CHRDL2 overexpression caused improvement in GCs-induced damages to BMECs that were partially eliminated by PI3K inhibitor LY294002. In conclusion, CHRDL2 is down-regulated in NFH samples and GCs-stimulated BMECs. CHRDL2 overexpression could improve GCs-caused BMEC apoptosis and dysfunctions, possibly via the PI3K/Akt pathway.

Light environment affects the efficiency of surgical suture training.

BACKGROUND: Suture knotting is the basis of surgical skills. In the process of surgical skills learning, the surrounding environment, especially the light, will affect the efficiency of learning. This study investigated the effect of optical environment on the learning of stitching and knotting skills. METHODS: A total of 44 medical students were randomly divided into four groups and participated in the study of suture knotting in four different optical environments. During the process, we assess objective pressure level by testing salivary amylase activity Likert scale and objective structured clinical examination (OSCE) was used to estimate the subjective psychological state and overall skill mastery in surgical suturing respectively. RESULTS: Under high illumination conditions (700 lx), the salivary amylase activity of the high color temperature group (6000 K) was significantly higher than that of the low color temperature group (4000 K) (p < 0.0001). Similarly, under low illumination (300 lx), the salivary amylase activity of the high color temperature group was also significantly higher than that of the low color temperature group (p < 0.05). The student under high illumination conditions (700 lx) and the low color temperature (6000 K) have an autonomy score between 37-45, which is significantly higher compared to the other three groups (p < 0.0001). Group 2 has an average OSCE score of 95.09, which were significantly higher than those of the other three groups (p < 0.05). CONCLUSION: High illumination combined with low color temperature is considered as the optimal training conditions, promoting trainees' optimism, reducing stress levels, and enhancing learning efficiency. These results highlight the pivotal role of light environment in improving the quality and efficiency of surgical skills training.

Both Acetabular and Femoral Reconstructions With Impaction Bone Grafting in Revision Total Hip Arthroplasty: Case Series and Literature Review.

Background: Extensive bone loss on femur and acetabulum posed a big challenge to orthopedists in total hip revision surgeries. Impaction bone grafting (IBG) as a valuable bone preservation technique could effectively address this problem. Either IBG revision on the femoral or acetabular side was well studied, while its use on both sides in one operation was not. The aim of this study is to present the outcomes of IBG on both femoral and acetabular sides at first-time hip revision. Methods: We retrospectively reviewed 8 patients (mean follow-up of 5.8 years) undergoing first-time revision with IBG on both acetabular and femoral sides at our institution. The Paprosky classification system was used to classify bone defects. Freeze-dried allografts and cemented prostheses were used in all patients. Postoperative complications and rerevision rates were reported. Results: Five patients presented a Paprosky type IIC acetabular defect, 3 with a type IIIB, IIIA, and IIC defect, respectively. Three patients presented with a type IV femoral defect, 3 with a type IIIB defect, and 2 with a type II defect. Two patients developed complications, while one had an intraoperative femoral fracture and one had delayed wound healing. At the latest follow-up, no patient had rerevisions or operations related to the prosthesis. Conclusions: IBG in combination with cemented prosthesis is a profitable biological reconstruction revision technique that could provide satisfying midterm outcomes. We first propose the use of blood clots mixed with bone grafts for potential bone incorporation enhancement, while its specific effects need to be verified in further studies.

GATA4-activated lncRNA MALAT1 promotes osteogenic differentiation through inhibiting NEDD4-mediated RUNX1 degradation.

Postmenopausal osteoporosis (PMOP) brings a lot of inconvenience to patients and serious economic burden to society. The osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) plays vital role in the process of PMOP treatment. However, the functional mechanism remains unclear. In this study, GATA4, MALAT1 and KHSRP were downregulated in bone tissues of PMOP patients, while NEDD4 was overexpressed. Through functional experiments, GATA4 overexpression strikingly accelerated osteogenic differentiation of BMSCs and promoted bone formation in vitro and in vivo, while these effects were dramatically reversed after MALAT1 silence. Intermolecular interaction experiments confirmed that GATA4 activated the transcription of MALAT1, which could form a 'RNA-protein' complex with KHSRP to decay NEDD4 mRNA. NEDD4 promoted the degradation of Runx1 by ubiquitination. Moreover, NEDD4 silencing blocked the inhibitory effects of MALAT1 knockdown on BMSCs osteogenic differentiation. In sum up, GATA4-activated MALAT1 promoted BMSCs osteogenic differentiation via regulating KHSPR/NEDD4 axis-regulated RUNX1 degradation, ultimately improving PMOP.

miR-122-5p targets GREM2 to protect against glucocorticoid-induced endothelial damage through the BMP signaling pathway.

Glucocorticoid (GC)-induced osteonecrosis of the femoral head (ONFH) accounts for a big portion of non-traumatic ONFH; nevertheless, the pathogenesis has not yet been fully understood. GC-induced endothelial dysfunction might be a major contributor to ONFH progression. The Gene Expression Omnibus (GEO) dataset was analyzed to identify deregulated miRNAs in ONFH; among deregulated miRNAs, the physiological functions of miR-122-5p on ONFH and endothelial dysfunction remain unclear. In the present study, miR-122-5p showed to be under-expressed within GC-induced ONFH femoral head tissues and GC-stimulated bone microvascular endothelial cells (BMECs). In human umbilical vein endothelial cells (HUVECs) and BMECs, GC stimulation significantly repressed cell viability, promoted cell apoptosis and increased the mRNA expression of proinflammatory cytokines, such as TNF-α, IL-1ß, and IFN-γ. After overexpressing miR-122-5p, GC-induced endothelial injuries were attenuated, as manifested by rescued cell viability, cell migration, and tube formation capacity. Regarding the BMP signaling, GC decreased the protein levels of BMP-2/6/7 and SMAD-1/5/8, whereas miR-122-5p overexpression significantly attenuated the inhibitory effects of GC on these proteins. Online tool and experimental analyses revealed the direct binding between miR-122-5p and GREM2, a specific antagonist of BMP-2. In contrast to miR-122-5p overexpression, GREM2 overexpression aggravated GC-induced endothelial injury; GREM2 silencing partially eliminated the effects of miR-122-5p inhibition on GC-stimulated HUVECs and BMECs. Finally, GREM2 silencing reversed the suppressive effects of GC on BMP-2/6/7 and SMAD-1/5/8, and attenuated the effects of miR-122-5p inhibition on these proteins upon GC stimulation. Conclusively, the present study demonstrates a miR-122-5p/GREM2 axis modulating the GC-induced endothelial damage via the BMP/SMAD signaling. Considering the critical role of endothelial function in ONFH pathogenesis, the in vivo role and clinical application of the miR-122-5p/GREM2 axis is worthy of further investigation.

RBP4 Is Associated With Insulin Resistance in Hyperuricemia-Induced Rats and Patients With Hyperuricemia.

Objective: Hyperuricemia (HUA) is strongly associated with abnormal glucose metabolism and insulin resistance (IR). However, the precise molecular mechanism of HUA-induced IR is still unclear. Retinol binding protein 4 (RBP4) has been shown to induce IR in type 2 diabetes mellitus. This study was designed to clarify the relationship between RBP4 and HUA-induced IR and its potential mechanisms. Methods: Patients with HUA were collected to detect the levels of plasma RBP4 and clinical biochemical indicators. Rats were fed with 10% high yeast and oteracil potassium (300 mg/kg) via intraperitoneal injection once daily for eight weeks, and gavage with adenine (100 mg/kg) once daily from the fifth week to induce the HUA model. Glucose consumption testing was performed to determine the capacity of glucose intake and consumption in 3T3-L1 adipocytes. Real-time polymerase chain reaction (RT-PCR) and western blot were used to detect the mRNA and protein level of RBP4 and insulin receptor substrate-phosphatidylinositol 3-kinase-active protein kinase (IRS/PI3K/Akt) signaling pathway-related proteins. Results: The levels of plasma RBP4 in both HUA patients and HUA rat models were significantly higher than that in the control groups. The level of plasma RBP4 was positively correlated with plasma uric acid, creatinine, fasting insulin, IR index, total cholesterol and triglyceride levels in patients with HUA. In HUA rats, the level of plasma RBP4 was positively correlated with plasma uric acid, IR index, and triglycerides. HUA rats also exhibited IR. After inhibition of RBP4 expression, the phosphorylation levels of the IRS/PI3K/Akt signaling pathway were increased, and IR was significantly improved. Conclusion: HUA induced IR both in vitro and in vivo. RBP4 may be involved in HUA-induced IR by inhibiting IRS/PI3K/Akt phosphorylation. Our findings may provide a new insight for the treatment of IR caused by HUA.

Arthroscopic reconstruction of coracoclavicular ligament by suspensory fixation for management of acute acromioclavicular joint dislocation and MRI follow-up study. / å ³èŠ‚é•œä¸‹å–™é”éŸ§å¸¦é‡å»ºæ‚¬åŠå¼å›ºå®šæ²»ç–—æ€¥æ€§è‚©é”å ³èŠ‚è„±ä½åŠMRI随访.

OBJECTIVES: To explore the safety and effectiveness of arthroscopic reconstruction of coracoclavicular ligament by suspensory fixation to manage the acute acromioclavicular joint dislocation. METHODS: From January 2016 to December 2017, 18 cases of acute acromioclavicular joint dislocation were carried out with arthroscopic reconstruction of coracoclavicular ligament by double Endobutton plate suspensory fixation. Anteroposterior view X-ray plain radiographs were obtained on the second day, 6 months and 12 months after the surgery, MRI was performed in 1 year after operation. Meanwhile, subjective and objective scoring were obtained by Vsual Analogue Scale (VAS), Rating Scale of the American Shoulder and Elbow Surgeons (ASES) and University of California at Los Angeles Shoulder Rating Scale (UCLA). RESULTS: All patients were followed up for 12 to 30 months (an average of 18 months). There was no patient with infection, neurovascular injury, loosening and breakage of internal fixation, re-dislocation of acromioclavicular joint, clavicular fracture, coracoid process fracture, etc. Postoperative X-ray showed that all acromioclavicular joints were completely relocated. The follow-up of MRI after 1 year showed no obvious dislocation of acromioclavicular joint and good recovery of acromioclavicular space. Postoperative shoulder joint function, VAS, ASES, UCLA and acromioclavicular distance were significantly improved compared with those before surgery, with statistically significant differences (all P<0.05). CONCLUSIONS: Arthroscopic reconstruction of coracoclavicular ligament by suspensory fixation to manage the acute acromioclavicular joint dislocation has the advantages of minimal invasive, rapid functional recovery and less complications and satisfactory early clinical results.

LncRNA MALAT1 promoted high glucose-induced pyroptosis of renal tubular epithelial cell by sponging miR-30c targeting for NLRP3.

Diabetic nephropathy (DN), characterized by the chronic loss of kidney function during diabetes, is a long-term kidney disease that affects millions of populations. However, the etiology of DN remains unclear. DN cell model was established by treating HK-2 cells with high glucose (HG) in vitro. Expression of metastasis-associated lung adenocarcinoma transcript-1 (MALAT1), miR-30c, nucleotide binding and oligomerization domain-like receptor protein 3 (NLRP3), caspase-1, IL-1ß, and IL-18 in treated HK-2 cells were tested by quantitative polymerase chain reaction. HK-2 cell pyroptosis was assessed using flow cytometry analysis. Lactate dehydrogenase (LDH) activity was examined with a LDH assay kit. Correlation among MALAT1, miR-30c, and NLRP3 was examined via dual-luciferase reporter assay. Here, we revealed that MALAT1 was upregulated, but miR-30c was downregulated in HG-treated HK-2 cells, leading to upregulation of NLRP3 expression and cell pyroptosis. Knockdown of MALAT1 or overexpression of miR-30c protected HK-2 cells from HG-induced pyroptosis. Meanwhile, we found that MALAT1 promoted NLRP3 expression by sponging miR-30c through dual-luciferase reporter assay. Moreover, the co-transfection of sh-MALAT1 and miR-30c inhibitor could reverse the protective effects of the sh-MALAT1 on the HG-induced pyroptosis. These results confirmed that MALAT1 regulated HK-2 cell pyroptosis by inhibiting miR-30c targeting for NLRP3, contributing to a better understanding of DN pathogenesis and help to find out the effective treatment for DN.

LncRNA-MALAT1 promotes osteogenic differentiation through regulating ATF4 by sponging miR-214: Implication of steroid-induced avascular necrosis of the femoral head.

OBJECTIVE: To study roles oflncRNA-MALAT1 and miR-214 in steroid-induced avascular necrosis of the femoral head (SANFH). METHODS: MALAT1, miR-214 andosteogenic-relatedgenes(Runx2, ALP, andOCN)expressions were determined in SANFH tissue samples and human bone marrow stromal cells (BMSC) by RT-qPCR. BMSCs were verifiedbyflowcytometry. The ATF4 level was determined by western blotting and RT-qPCR. Osteogenesis inducedbyosteogenic medium (OM) in BMSCs and dexamethasone (DEX) was used to inhibit osteogenesis. The alkaline phosphatase (ALP) activity was measured and ALP staining and alizarin red staining were conducted for evaluation of osteogenic differentiation. MTT assay was used for cell proliferation. The dual luciferase reporter assay was used to confirm binding between MALAT1 and miR-214, as well as miR-214 and ATF4. RESULTS: MALAT1 was down-regulated and miR-214 was up-regulated in SANFH tissues. DEX inhibited osteogenic differentiation of BMSC in a dose-dependent manner, leading to decreased MALAT1, increased miR-214, as well as reduced ALP activity and decreased expression of RUNX2, ALP and OCN. Either overexpression of MALAT1 or inhibition of miR-214 improved DEX-induced inhibition of BMSC osteogenic differentiation. The overexpression of miR-214 reversed the effects by MALAT1. MALAT1 directly sponged miR-214 and miR-214 directly targeted ATF4. CONCLUSION: MALAT1 was down-regulated, while miR-214 was elevated in SANFH tissues. MALAT1 promoted osteogenesis differentiation by sponging miR-214 to upregulate ATF4.

Effects of AURKA-mediated degradation of SOD2 on mitochondrial dysfunction and cartilage homeostasis in osteoarthritis.

This study aimed to investigate the mechanism of the ubiquitinase Aurora kinase A (AURKA) in the occurrence of osteoarthritis (OA) by mediating mitochondrial stress. Bioinformatic predictions revealed 2247 differentially expressed genes (DEGs) in the normal and OA tissues. According to the UbiNet database, 39 DEGs that code for ubiquitination enzymes was screened. AURKA was highly expressed in OA tissues and cells. AURKA interference inhibited the elevation of matrix metalloproteinase-13 (MMP-13). (MMP13), sex determining region Y-box 9 (Sox9), and a disintegrin and metalloproteinase with thrombospondin motifs-5 (ADAMTS5) expression and the reduction of collagen type IIα (Col2a1) and Aggrecan expression in interleukin-1 ß (IL-1ß) induced chondrocytes. The animal experiments proved that depleting AURKA could repress the occurrence of OA. Superoxide dismutase 2 (SOD2) was determined to be AURKA ubiquitination substrate via AURKA expression and bioinformatic prediction experiments. SOD2 expression was lower in OA tissues, but higher in normal joint tissues. AURKA interference activates SOD2. Meanwhile, the IP results confirmed that AURKA could bind to SOD2 and degrade it through K48 ubiquitination. Modification and overexpression of AURKA reduce SOD2 levels. AURKA interference can reverse the reactive oxygen species elevation caused by SOD2 overexpression or lysine-48 (K48) mutation, respectively, leading to mitochondrial dysfunction. Furthermore, AURKA silencing suppressed the occurrence of OA induced by mitochondrial activation. These findings suggest that ubiquitination of AURKA lowers SOD2 expression and affects mitochondrial dysfunction to repress the occurrence of OA. The results of the current study reveal that AURKA ubiquitination influences mitochondrial dysfunction and suppresses the occurrence of OA via degradation of SOD2. These data reveal novel potential targets for OA treatment.

IL-1ß-induced miR-34a up-regulation inhibits Cyr61 to modulate osteoarthritis chondrocyte proliferation through ADAMTS-4.

Osteoarthritis (OA) is the most prevalent degenerative joint disease with multifactorial etiology caused by risk factors. The degradation of aggrecan by upregulated ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) is the key event in the development of OA. ADAMTS-4 contributes to aggrecan degradation in human OA. Cysteine-rich angiogenic inducer 61 (Cyr61), which is associated with diseases related to chronic inflammation, is found in articular cartilage from patients with osteoarthritis and appears to suppress ADAMTS-4 activity, possibly leading to chondrocyte cloning. Herein, we first revealed that Cyr61 and ADAMTS-4 protein levels were remarkably increased in OA cartilage tissues and OA chondrocytes, and verified Cyr61 regulation of ADAMTS-4 in normal and OA chondrocyte. Further, we revealed that Cyr61 could promote OA chondrocyte proliferation through inhibiting ADAMTS-4. Overproduction of inflammatory cytokines plays a vital role in the pathological development of OA; herein, we demonstrated that IL-1ß inhibited Cyr61, while promoted ADAMTS-4 expression. By using online tools and luciferase assays, we confirmed that miR-34a, a regulatory miRNA of chondrocyte proliferation, could directly bind to the 3'-UTR of Cyr61 to inhibit its expression; further, IL-1ß regulated Cyr61 and ADAMTS-4 expression through miR-34a. In OA cartilage tissues, miR-34a, and IL-1ß mRNA expression was up-regulated and positively correlated; miR-34a and Cyr61 mRNA was positively correlated, further indicating that suppressing miR-34a expression might rescue IL-1ß-induced Cyr61 suppression, and promote OA chondrocyte proliferation. Taken together, we provided novel experimental basis for rescuing OA chondrocyte proliferation through miR-34a/Cyr61 axis.

MALAT1 promotes osteosarcoma development by regulation of HMGB1 via miR-142-3p and miR-129-5p.

Recently, emerging evidence has demonstrated that metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a long non-coding RNAs (lncRNAs), contributes to the initiation and development of tumors, including osteosarcoma (OS). Multiple studies have suggested an oncogenic role of MALAT1 and high-mobility group protein B1 (HMGB1) in OS tumorigenesis and metastasis, but the effects and mechanisms are not unanimous. Here, we showed that MALAT1 and HMGB1 were significantly increased in human OS cell lines and knockdown of MALAT1 reduced HMGB1 expression. By using online tools, we screen out 2 candidate miRNAs, miR-142-3p and miR-129-5p which may be associated with both MALAT1 and HMGB1. Luciferase reporter assay revealed a direct interaction between the 2 miRNAs and MALAT1, respectively, via a putative binding site within MALAT1. Meanwhile, both the 2 miRNAs could bind to HMGB1 3'-untranslated region (3'-UTR) and regulate HMGB1 expression. Moreover, knockdown of MALAT1 decreased HMGB1 expression, inhibited OS cell growth and promoted apoptosis, while miR-142-3p and miR-129-5p inhibitor partly restored the inhibitory effect of MALAT1 knockdown on HMGB1 expression, OS cell growth and the promotion of apoptosis. In OS tissues, the expression of MALAT1 and HMGB1 was upregulated while the expression of miR-142-3p and miR-129-5p was downregulated. Together, our results support a MALAT1/miR-142-3p/miR-129-5p/HMGB1 axis in OS cell proliferation and tumor progression. MALAT1 promoted OS cell growth through inhibition of miR-142-3p or miR-129-5p and by targeting HMGB1.