PI3K-Akt-mTOR inhibition by GNE-477 inhibits renal cell carcinoma cell growth in vitro and in vivo

Sustained activation of PI3K-Akt-mTOR cascade is important for renal cell carcinoma (RCC) cell progression. GNE-477 is a novel and efficacious PI3K-mTOR dual inhibitor. The current study tested its anti-RCC cell activity. In the primary cultured human RCC cells, GNE-477 potently inhibited cell growth, viability and proliferation, as well as cell cycle progression, migration and invasion. Furthermore, it induced robust apoptosis activation in primary RCC cells, but being non-cytotoxic to HK-2 epithelial cells and primary human renal epithelial cells. In the primary RCC cells GNE-477 inactivated PI3K-Akt-mTOR cascade by blocking phosphorylation of p85, Akt1, p70S6K1 and S6. Restoring Akt-mTOR activation by a constitutively-active Akt1 reversed GNE-477-induced anti-RCC cell activity. In nude mice intraperitoneal injection of GNE-477 potently suppressed RCC xenograft tumor growth. Collectively, targeting PI3K-Akt-mTOR cascade by GNE-477 inhibits RCC cell growth in vitro and in vivo.

[Effect of changes of inflammatory factors on prognosis of tibia plateau Schatzker Ⅲ fractures treated under arthroscopic or open reduction and internal fixation]

OBJECTIVE

To explore changes of inflammatory factors on prognosis of tibia plateau Schatzker Ⅲ fractures treated under arthroscopic or open reduction and internal fixation.

METHODS

From November 2013 to November 2016, clinical data of 30 patients with tibia plateau Schatzker Ⅲ fractures were retrospectively analyzed, and divided into minimally invasive group and control group according to different surgical methods 15 patients in each group. Minimally invasive group were treated by arthroscopic internal fixation, including 8 males and 7 females, aged from 20 to 50 years old with an average of (35.0± 14.6) years old, the time from injury to operation ranged from 7 to 15 days with an average of (11.0±4.1) days. Control group were treated by open reduction and internal fixation, including 7 males and 8 females, aged from 18 to 48 years old with an average of (33.0±13.6) years old, the time from injury to operation ranged from 6 to 14 days with an average of (10.0±3.4) days.Operation time, length of incision, blood loss, postoperative loading time and fracture healing time, complications were compared between two groups. Level of IL-1β, IL-6, TNF-α were detected at 3 days, 6 months and 12 months after operation, Lysholm knee function score at 6 and 12 months were compared between two groups.

RESULTS

Allpatients were followed up, but there was no significant difference in following up between two groups. Operation time, length of incision, blood loss, postoperative loading time, fracture healing time and cases of complications in minimally invasive group were (80.3±9.7) min ,(4.2± 1.0) cm ,(102.2±26.4) ml ,(30.0±10.0) d ,(70.0±5.0) d and 0 case respectively; while in control group were (90.3±9.1) min, (10.5±1.1) cm ,(221.1±46.8) ml ,(50.0±15.0) d ,(90.0±6.0) d and 2 cases respectively; there were significant difference between two groups. Lysholm score in minimally invasive group 89.2±5.1 was higher than that of control group 80.1±3.1; and score of swelling, squat and pain in minimally invasive group was higher than that of control group at 6 months after opertaion. While there were no significant difference in each items and total score of Lysholm score between two groups at 12 months after operation. Level of IL-1β, IL-6, and TNF-α in minimally invasive group at 3 days and 6 months were [(52.1±20.1) pg/L, (0.9±0.1) pg/L ],[(56.1±20.1) pg/L ,(1.1±1.3) pg/L ] and [(28.3±2.5) pg/L ,(8.4±1.5) pg/L ] respectively; while in control group were [(64.8±9.1) pg/L ,(8.1±2.1) pg/L ],[(65.8±12.3) pg/L ,(9.1±5.3) pg/L ] and [(38.5±2.3) pg/L ,(26.5± 1.4) pg/L ] respectively; there were statistically difference in level IL-1β, IL-6 and TNF-α between two groups at 3 days and 6 months after operation; while there was no difference at 12 months after operation (P>0.05) . Inflammatory cytokines level at 3 days after operation IL-1β [OR=1.279, 95%CI (1.047, 1.512), P<0.05 ], IL-6 [OR=1.687, 95%CI (1.478, 1.888), P<0.05 ], TFN-α [ OR=2.096, 95%CI (1.863, 2.316), P<0.05 ] was an independent risk factor for Lysholm knee function score at 6 months after operation.

CONCLUSION

Arthroscopic surgery and open surgery also could obtain good clinical effects in treating tibia plateau Schatzker Ⅲ fractures. Arthroscopic internal fixation could shorten operation time, lessen the mount of blooding with minimally invasive, lower occurrence of postoperative complications, faster recovery of knee function.

The therapeutic value of the SphK1-targeting microRNA-3677 in human osteosarcoma cells

Sphingosine kinase 1 (SphK1) is a potential therapeutic target for human osteosarcoma (OS). SphK1-targeting microRNAs (miRNAs) could have important therapeutic value for OS. We discovered that micorRNA-3677 (miR-3677) is a SphK1-targeting miRNA, inhibiting OS cell progression. The results of RNA-Pull down assay confirmed direct binding between biotinylated-miR-3677 and SphK1 mRNA in primary human OS cells. In established and primary human OS cells forced overexpression of miR-3677, by a lentiviral construct, decreased SphK1 3’-UTR (untranslated region) activity and downregulated SphK1 expression. Both were however enhanced with miR-3677 inhibition in OS cells. Function studies demonstrated that OS cell growth, proliferation and migration were inhibited with miR-3677 overexpression, but augmented with miR-3677 inhibition. MiR-3677 overexpression-induced anti-OS cell activity was reversed with re-expression of the 3’-UTR-depleted SphK1. Additionally, in SphK1 knockout OS cells (by CRISPR/Cas9 strategy), altering miR-3677 expression failed to further alter cell functions. Finally, we show that miR-3677 expression was significantly downregulated in primary human OS tissues, correlating with SphK1 mRNA upregulation. We conclude that targeting SphK1 by miR-3677 inhibits human OS cell progression.

[Ultrasound-guided minimal traverse-cross technique repair for acute closed Achilles tendon ruptures]

OBJECTIVE

To explore clinical effects of ultrasound-guided minimal traverse-cross technique repair for acute closed Achilles tendon ruptures.

METHODS

From January 2015 to March 2017, 20 patients with acute closed Achilles tendon rupture were treated by minimal traverse-cross technique repair with ultrasound guided. Among them, including 13 males and 7 females, aged from 28 to 49 years old with an average of(31.3 ±4.5) years old. All patients were single side injury. Fifteen patients on the left side and 5 patients were on the right side. The time from injury to operation ranged from 1 to 5 days with an average of (2.5±0.7) days. Operative time, postoperative complications were observed, and AOFAS score before and after operation at 12 months were compared.

RESULTS

All patients were followed up for 12 to 27 months with an average of(15.2±4.9) months. Operative time ranged from 33 to 65 min with an average of(43.7±5.6) min. Incision of one patient were continued oozing and improved after changing dressings, other patients were healed at stage I. No sural nerve irritation symptoms and palindromic rapture of heel tendon occurred. AOFAS score was improved from 65.2±7.4 before operation to 97.7±4.7 after operation at 12 months (t=22.5, P<0.01); 18 patients got excellent results and 2 good.

CONCLUSIONS

Ultrasound-guided minimal traverse-cross technique repair for acute closed Achilles tendon ruptures, which promise minimal incision, protect sural nerve, ensure quality of tendon anastomosis and fixation, and is a ideal method for repairing acute closed Achilles tendon ruptures.

[Analysis of hidden blood loss after percutaneous kyphoplasty for osteoporotic vertebral compression fracture and its influencing factors]

OBJECTIVE

To investigate the hidden blood loss and related risk factors of osteoporotic vertebral compression fractures after percutaneous kyphoplasty.

METHODS

The clinical data of 153 patients with osteoporotic vertebral compression fractures who underwent percutaneous kyphoplasty from March 2015 to December 2017 were retrospectively analyzed, including 55 males and 98 females, aged 68 to 87(78.6±11.4) years old. Erythrocyte specific volume was collected before and after operation to calculate the hidden blood loss. The influence of sex, age, body mass index, bone mineral density, diabetes mellitus and hypertension, operation mode (unilateral or bilateral), operation time, operative segment and number, loss height of vertebral body and recovery height ratio on hidden blood loss was analyzed by multiple linear regression model.

RESULTS

Postoperative hidden blood loss was (287.7±68.5) ml. Multivariate linear regression analysis showed that the history of diabetes mellitus (β=2.405, P=0.012), the mode of operation(β=3.042, P<0.001), the time of operation (β=2.043, P=0.038), the operative segment (β=1.993, P=0.043), the number (β=0.374, P<0.001), the loss of vertebral height (β=2.785, P=0.003) and the recovery ratio(β=7.301, P<0.001) were correlated with occult hemorrhage.

CONCLUSIONS

There is a certain degree of occult hemorrhage in kyphoplasty for osteoporotic vertebral compression fractures. The risk factors of hidden hemorrhage are diabetes history, operation method, operation time, operative segment and number, loss of vertebral height and recovery ratio.

[Trichloroethylene-induced abnormal methylation on promoter region of SET in hepatic L-02 cells]

Objective: To explore the trichloroethylene-induced alteration of methylation on the promoter region of SET and related mechanisms in hepatic L-02 cells. Methods: L-02 cells were treated with different concentrations of TCE(0 mmol/L, 1 mmol/L, 2 mmol/L, 4 mmol/L, 8 mmol/L) for 24 h. The genomic DNA were then extracted and modified by bisulfite sodium. The DNA methylation was then analyzed using bisulfite sequencing PCR (BSP). Results: The overall methylation on promoter region of SET was decreased along with the increased concentrations of TCE in hepatic L-02 cells. Moreover, 73 CpG islands were found abnormally altered, among which 9 were predicted in transcriptional factor binding regions. Conclusion: The decreased levels of CpG islands in the transcriptional factor binding region may contribute to the elevation of SET in TCE-induced hepatotoxicity.

microRNA-29a inhibition induces Gab1 upregulation to protect OB-6 human osteoblasts from hydrogen peroxide

The present study determines the role of the Gab1 in hydrogen peroxide (H₂O₂)-induced death of human osteoblasts. We show that Gab1 is required for H₂O₂-induced Akt activation to promote osteoblast survival. In OB-6 human osteoblasts, Gab1 silencing (by targeted-shRNA) or complete knockout (by CRISPR-Cas9 KO plasmid) largely attenuated Akt activation by H₂O₂. Gab1-depleted OB-6 cells were more vulnerable to H₂O₂. Conversely, forced over-expression of Gab1 by an adenovirus vector increased Akt activation to protect OB-6 cells from H₂O₂. Significantly, the anti-sense of microRNA-29a ("antagomiR-29a") induced Gab1 expression to facilitate H₂O₂-induced Akt activation, which protected OB-6 cells from apoptosis. AntagomiR-29a was however ineffective in Gab1-deficient and Akt-inhibited OB-6 cells. Forced over-expression of miR-29a induced Gab1 downregulation to inhibit H₂O₂-induced Akt activation, causing enhanced OB-6 cell death. miR-29a-induced actions were abolished by an adenovirus constitutively-active Akt1 (Ad-caAkt1) in OB-6 cells. Together, microRNA-29a inhibition induces Gab1 upregulation and Akt activation to protect OB-6 osteoblasts from H₂O₂.

miR-135b expression downregulates Ppm1e to activate AMPK signaling and protect osteoblastic cells from dexamethasone

Activation of AMP-activated protein kinase (AMPK) could potently protect osteoblasts/osteoblastic cells from dexamethasone (Dex). We aim to induce AMPK activation via microRNA ("miRNA") downregulation of its phosphatase Ppm1e. We discovered that microRNA-135b ("miR-135b") targets the 3' untranslated regions (UTRs) of Ppm1e. In human osteoblasticOB-6 cells and hFOB1.19 cells, forced-expression of miR-135b downregulated Ppm1e and activated AMPK signaling. miR-135b also protected osteoblastic cells from Dex. shRNA-induced knockdown of Ppm1e similarly activated AMPK and inhibited Dex-induced damages. Intriguingly, in the Ppm1e-silenced osteoblastic cells, miR-135b expression failed to offer further cytoprotection against Dex. Notably, AMPK knockdown (via shRNA) or dominant negative mutation abolished miR-135b-induced AMPK activation and cytoprotection against Dex. Molecularly, miR-135b, via activating AMPK, increased nicotinamide adenine dinucleotide phosphate (NADPH) activity and inhibited Dex-induced oxidative stress. At last, we found that miR-135b level was increased in human necrotic femoral head tissues, which was correlated with Ppm1e downregulation and AMPK activation. There results suggest that miR-135b expression downregulates Ppm1e to activate AMPK signaling, which protects osteoblastic cells from Dex.

[An investigation of trichloroethylene-induced effects on histone methylation in L-02 hepatic cells]

Objective: To further explore TCE-induced hepatotoxicity and its mechanisms by identification of trichloroethylene (TCE) induced abnormal histone methylation in human liver cells. Methods: L-02 cells were treated with 0 and 8 mmol/L TCE for 24 h. Histones were extracted by acid. Liquid chromatography electrospray ionization tandem mass spectrometry (ESI-LC-MS/MS) were used to identify and quantify TCE related histone methylations. TCE induced abnormal methylation of H3K79 me2 and H3K79 me3 were validated by Western blot analysis. The further analysis of the function of histone abnormal methylation modifications were done by single cell gel electrophoresis (SCGE) and Western blot analysis of p53 and ɤH2AX. Results: After treatment with TCE for 24 h in L-02 cells, the 36 TCE related histone methylation sites in 28 peptide segments were identified by MS. After treatment with TCE in concentrations of 0 and 8.0 mmol/L in L-02 cells for 24 h, the relative expression level of histone H3K79 me3 were 1.00±0.06, 0.70±0.09 (t=15.01, P=0.015); the relative expression level of histone H3K79 me2 were 1.00±0.05, 0.74±0.07 (t=16.69, P=0.018); the Olive Tail Moment about DNA damage were 1.46±0.28, 3.12± 0.68 (t=15.22, P=0.018); the relative expression levels of p53 were 1.00±0.04, 1.24±0.04 (t=18.71, P= 0.012); and the relative expression levels of ɤH2AX were 1.00 ± 0.03, 1.56 ± 0.11 (t=8.32, P=0 045). Conclusion: TCE can induce changes in the relative expression level of H3K79 me2 and H3K79 me3 in L-02 cell, and induce DNA damage, suggesting that TCE may induce changes in the relative expression level of H3K79 me2 and H3K79 me3 by DNA damage.

SC79 rescues osteoblasts from dexamethasone though activating Akt-Nrf2 signaling

Dexamethasone (Dex) causes osteoblast cell injuries. In the present research, we tested the potential effect of SC79, a novel and specific Akt activator, against Dex in osteoblasts. In primary murine osteoblasts and osteoblastic MC3T3-E1 cells, pretreatment with SC79 significantly attenuated Dex-induced cell death. Further, Dex-induced mitochondrial permeability transition pore (mPTP) opening, cytochrome C release and apoptosis activation were dramatically alleviated with SC79 pretreatment in above cells. At the molecular level, SC79 activated Akt, which was indispensable for subsequent osteoblast protection against Dex. Akt inhibitors (LY294002, perifosine and MK-2206) blocked SC79-induced Akt activation and abolished its anti-Dex actions in osteoblasts. Further, SC79 activated Akt downstream Nrf2 (NF-E2-related factor 2) signaling and attenuated Dex-induced oxidative stress in osteoblasts. Nrf2 shRNA knockdown or S40T mutation almost reversed SC79-mediated anti-oxidant and cytoprotective activities in osteoblasts. Together, these results suggest that SC79 activates Akt-Nrf2 signaling to protect osteoblasts from Dex.

A multi-prong global study provides insights to gut microbiota and mucosal immunity in dusp6-deficiency conferred obesity-resistance

Obesity is now a plague in developed countries and more than one third of U.S. adults are obese. Gut microbiota plays profound roles in host energy harvest, metabolism and inflammatory response associated with the development of obesity. Dusp6-deficient mice have been shown to be resistant to diet-induced-obesity (DIO) but the mechanism is still unclear. Using a gnotobiotic mouse model, we found that the transplantation of fecal/gut microbiota derived from dusp6-deficient mice can significantly increase energy expenditure and reduce weight-gain of the recipient mice. By analyzing fecal 16s rRNA genes, dusp6-deficient mice have different composition of gut microbiota when compared with wild-type mice. We also demonstrated that dusp6-deficient mice were resistant to DIO-mediated dysbiosis of gut microbiota. Upon further analysis of the intestinal transcriptome, we found that dusp6 deficiency is an important regulator of several metabolic pathways and genes related to intestinal barrier. Moreover, our analyses have shown that dusp6-deficient mice could alleviate DIO-induced inflammation.. This study demonstrates that dusp6 deficiency is a strong genetic factor that dominates diet effect on shaping gut microbiota and it remodels mucosal immunity to retain HFD-resistant homeostasis of gut microbiota. Our findings shed lights on obesity and obesity-derived metabolic disease treatment with novel therapeutic candidates/strategies such as DUSP6 pharmacological inhibitors and the development of microbiota-based therapeutics.

A reduction clamp for an aiming component in associated acetabular fractures

BACKGROUND

The treatment of acetabular fractures is complex and requires specialized equipment. However, all currently available instruments have some disadvantages. A new reduction clamp that can firmly enable reduction and not hinder subsequent fixation procedures for some special fracture types is needed.

MATERIALS AND METHODS

In this study, we introduce a new acetabular clamp and its preliminary clinical application in three T-shaped acetabular fractures.

RESULTS

This new clamp can successfully pull the posterior column back to the anterior column and firmly maintain the reduction. This clamp's aiming plate can facilitate the insertion of long lag screws. The clamp is also easy to assemble and use.

CONCLUSION

This reduction clamp is a useful instrument that can facilitate open reduction and internal fixation of acetabular fractures.

Overexpressed hPTTG1 promotes breast cancer cell invasion and metastasis by regulating GEF-H1/RhoA signalling

Human pituitary tumour-transforming gene 1 (hPTTG1) is an oncogenic transcription factor that is overexpressed in many tumour types, especially tumours with metastatic abilities. However, how hPTTG1 overexpression drives metastasis is not yet clear. As a transcription factor, hPTTG1 may promote metastasis by activating target genes that are involved in the metastatic process. Here, we showed that Rho guanine nucleotide exchange factor-H1 (GEF-H1) was transcriptionally activated by hPTTG1, thereby promoting breast cancer metastasis. Luciferase reporter analyses and chromatin immunoprecipitation (ChIP) assays showed that hPTTG1 directly bound and activated the GEF-H1 gene promoter. In this study, RNA interference-mediated knockdown of hPTTG1 in highly metastatic breast tumour cells decreased GEF-H1 expression and RhoA activation, thereby reducing cell motility and invasion, and interfering with cytoskeletal remodelling in vitro, and impairing the tumour metastasis in vivo. The restoration of GEF-H1 expression in hPTTG1-knockdown cells rescued the hPTTG1-knockdown effects on cytoskeletal changes in vitro and tumour metastasis in vivo. Conversely, ectopic expression of hPTTG1 in non-metastatic breast tumour cells induced cytoskeletal rearrangements, and allowed these cells to metastasise in a mouse model by orthotopic implantation. In human tumour samples, hPTTG1 expression was also correlated to GEF-H1 expression in aggressive breast carcinoma. Altogether, these findings definitively establish a role for hPTTG1 in activating the GEF-H1/RhoA pathway as a newly identified mechanism in breast cancer metastasis.

[Treatment of atlantoaxial instability with C1-C2 posterior transarticular screw fixation]

OBJECTIVE

To evaluate the technique of C1-C2 transarticular screw fixation for atlantoaxial instability or dislocation.

METHODS

Among 14 patients with atlantoaxial instability, 10 were male and 4 patients were female, with an average age of 38.6 years ranging from 17 to 62 years. All patients were treated by internal fixation with transarticular screws.

RESULTS

There were 28 screws applied in 14 patients. All patients were followed up. The average follow-up period was 16 months (range, 9 to 35 months). The postoperative JOA score was ranging from 13.8 to 15.8 with the average score of (14.50 +/- 0.66) and the improved rate of (76.12 +/- 4.94)%. No spinal injury and vertical artery injury was found and osseous fusion was completed in all patients.

CONCLUSION

The technique of C1-C2 transarticular screw fixation is one of the best treatments for atlantoaxial instability. Without the help of structural bone graft and aided internal fixation, morselized cancellous bone graft can acquire effective osseous fusion.

Fc and C3b receptors on pulmonary endothelial cells: induction by injury

Receptors for the activated third component of complement and for the Fc portion of immunoglobulin G are not expressed by apparently normal bovine pulmonary endothelial cells, but are expressed when the cells are exposed to white cell lysates or are infected with influenza or cytomegalovirus. The unmasking of these latent receptors may contribute to the pulmonary inflammatory response characteristic of, for example, anaphylaxis and to those lung diseases characterized by the deposition of immune complexes.