Osteocyte-derived exosomes induced by mechanical strain promote human periodontal ligament stem cell proliferation and osteogenic differentiation via the miR-181b-5p/PTEN/AKT signaling pathway

BACKGROUND

The oral cavity is a complex environment in which periodontal tissue is constantly stimulated by external microorganisms and mechanical forces. Proper mechanical force helps maintain periodontal tissue homeostasis, and improper inflammatory response can break the balance. Periodontal ligament (PDL) cells play crucial roles in responding to these challenges and maintaining the homeostasis of periodontal tissue. However, the mechanisms underlying PDL cell property changes induced by inflammatory and mechanical force microenvironments are still unclear. Recent studies have shown that exosomes function as a means of cell-cell and cell-matrix communication in biological processes.

METHODS

Human periodontal ligament stem cells (HPDLSCs) were tested by the CCK8 assay, EdU, alizarin red, and ALP staining to evaluate the functions of exosomes induced by a mechanical strain. MicroRNA sequencing was used to find the discrepancy miRNA in exosomes. In addition, real-time PCR, FISH, luciferase reporter assay, and western blotting assay were used to investigate the mechanism of miR-181b-5p regulating proliferation and osteogenic differentiation through the PTEN/AKT pathway.

RESULTS

In this study, the exosomes secreted by MLO-Y4 cells exposed to mechanical strain (Exosome-MS) contributed to HPDLSC proliferation and osteogenic differentiation. High-throughput miRNA sequencing showed that miR181b-5p was upregulated in Exosome-MS compared to the exosomes derived from MLO-Y4 cells lacking mechanical strain. The luciferase reporter assay demonstrated that miR-181b-5p may target phosphatase tension homolog deletion (PTEN). In addition, PTEN was negatively regulated by overexpressing miR-181b-5p. Real-time PCR and western blotting assay verified that miR-181b-5p enhanced the protein kinase B (PKB, also known as AKT) activity and improved downstream factor transcription. Furthermore, miR-181b-5p effectively ameliorated the inhibition of HPDLSC proliferation and promoted HPDLSC induced by inflammation.

CONCLUSIONS

This study concluded that exosomes induced by mechanical strain promote HPDLSC proliferation via the miR-181b-5p/PTEN/AKT signaling pathway and promote HPDLSC osteogenic differentiation by BMP2/Runx2, suggesting a potential mechanism for maintaining periodontal homeostasis.

Serum hepatitis B surface antigen correlates with fibrosis and necroinflammation: A multicentre perspective in China

The kinetics of serum hepatitis B surface antigen (HBsAg) during the natural history of hepatitis B virus (HBV) infection has been studied, but the factors affecting them remain unclear. We aimed to investigate the factors affecting HBsAg titres, using data from multicentre, large-sized clinical trials in China. The baseline data of 1795 patients in 3 multicentre trials were studied, and the patients were classified into 3 groups: hepatitis B early antigen (HBeAg)-positive chronic HBV infection (n = 588), HBeAg-positive chronic hepatitis B (n = 596), and HBeAg-negative chronic hepatitis B (n = 611). HBsAg titres in the different phases were compared, and multiple linear progression analyses were performed to investigate the implicated factors. HBsAg titres varied significantly in different phases (P = .000), with the highest (4.60 log10 IU/mL [10%-90% confidence interval: 3.52 log10 IU/mL-4.99 log10 IU/mL]) in patients with HBeAg-positive chronic HBV infection. In all phases, age and HBV DNA were correlated with serum HBsAg level. In HBeAg-positive chronic hepatitis B patients, a negative correlation between HBsAg titres and fibrosis stage was observed. Alanine amonitransferase or necroinflammatory activity was also correlated with HBsAg titres in HBeAg-negative chronic hepatitis B patients. In conclusion, decreased HBsAg titres may be associated with advancing fibrosis in HBeAg-positive chronic hepatitis B patients or increased necroinflammation in those with HBeAg-negative chronic hepatitis B. Our findings may help clinicians better understand the kinetics of HBsAg and provide useful insights into the management of this disease.

[Clinical efficacy of enhanced recovery after surgery in atrial caval shunting for type Ⅱ Budd-Chiari syndrome]

Objective: To investigate the clinical efficacy of enhanced recovery after surgery(ERAS) in atrial caval shunting (ACS) for type Ⅱ Budd-Chiari syndrome(BCS). Methods: The clinical data of patients underwent ACS for type Ⅱ BCS in the Henan Province People's Hospital from January 2014 to June 2016 were prospectively analyzed.Randomized and single-blind, controlled study was performed among the patients, and all of them underwent ACS and were divided into control group (patients underwent traditional perioperative management) and ERAS group (patients underwent ERAS perioperative management) based on a random number table.Operational and postoperative data, levels of inflammatory cytokines, stress state evaluation and postoperative complications were observed.The comparison between the two groups was evaluated with an independent sample t test.The trend analyses for variables were done using repeated measures ANOVA.The count data were analyzed using the chi-square test or Fisher exact. Results: Eighty-two patients were screened for eligibility, and allocated into the control group (40 patients) and the ERAS group (42 patients). All patients underwent ACS successfully with no death.Comparison of intraoperative status: operation time, volume of intraoperative blood and number of patients receiving blood transfusion were (211.0±12.9) minutes vs. (207.7±10.7) minutes, (167.5±28.3) ml vs. (165.0±28.4) ml and 3 cases vs. 1 case between the control group and the ERAS group, respectively, showing no difference between the two groups (t=0.90, 0.29, χ²=0.32, all P>0.05). Comparison of postoperative status: time of gastric tube removal, time of catheter removal, time of chest tube, time to flatus, time of food intake, duration of postoperative infusion, duration of postoperative hospital stay and numeric rating scale were (3.7±0.5)days vs. (0.0±0.0)days, (2.3±0.7)days vs. (1.4±0.5)days, (3.7±0.7)days vs. (2.3±0.5)days, (75.2±3.8)hours vs. (46.6±4.2)hours, (75.7±4.7)hours vs. (21.4±2.1)hours, (10.0±1.0)days vs. (5.8±0.9)days, (11.4±1.0)days vs. (7.8±0.6)days, 2.9±0.4 vs. 1.9±0.6 between the control group and the ERAS group, respectively, with statistically differences (t=35.03, 4.36, 8.10, 22.89, 47.78, 14.75, 14.22, 6.13, all P<0.05). Stress state evaluation: the levels of IR were (2.7±0.1) vs.(2.7±0.1), (8.8±0.7) vs. (5.2±0.3), (11.0±0.5) vs. (7.3±0.5), (4.9±0.2) vs. (3.9±0.1), and the levels of C-reaction protein were (14.6±1.3)mg/L vs.(14.6±1.1) mg/L, (101.2±13.6) mg/L vs. (89.5±6.9) mg/L, (62.7±8.6) mg/L vs. (56.4±8.4) mg/L, (46.4±6.7) mg/L vs. (40.0±5.6) mg/L from pre-operation to postoperative day 1, 3 and 5 between the control group and the ERAS group, respectively, with statistically significant differences in changing trends(F=136.61, 4.97, both P<0.05). Comparisons of levels of inflammatory cytokines: the levels of IL-6 were (43.1±2.7) ng/L vs. (43.6±3.6) ng/L, (135.1±6.4) ng/L vs. (117.4±5.7) ng/L, (145.4±6.7) ng/L vs. (128.5±5.5) ng/L, (93.3±3.7) ng/L vs. (88.0±3.9) ng/L, and the levels of TNF-α were (10.4±0.3)mmol/L vs. (10.4±0.3) mmol/L, (14.4±0.4) mmol/L vs. (12.6±0.4) mmol/L, (15.6±0.4) mmol/L vs. (13.8±0.4) mmol/L, (12.3±0.7) mmol/L vs. (11.4±0.6) mmol/L from pre-operation to postoperative day 1, 3 and 5 between the control group and the ERAS group, respectively, with statistically significant differences in changing trends (F=15.15, 21.45, both P<0.05). Comparison of postoperative complications: incidence of complications was 30.0%(12/40) in the control group and 11.9%(5/42) in the ERAS group, and the numbers of patients with nausea and vomiting, respiratory complications and cardiovascular complications were 4, 3, 5 cases in the control group and 3, 1, 1 case in the ERAS group, respectively, showing statistically differences in the incidence of complications(χ²=4.08, P<0.05). All the 82 patients were followed up for 2 to 22 months (median time, 12 months), no patients received reoperation or re-admitted to the hospital duo to complications. Conclusion: ERAS management in the perioperative period of ACS for BCS is beneficial to postoperative recovery of patients, and can relieve postoperative stress state and inflammatory response, reduce the duration of hospital stay, and incidence of postoperative complications.

[Studies on the synthesis and bioactivity of alpha-alkylaminobenzyl-phosphonic acids]

AIM

To search for some substituted benzyl phosphonic acids as leading compounds with inhibiting effect on osteoclast formation.

METHODS

Target compounds were prepared from aromatic aldehydes, primary amine and phosphorous acid using tetramethylenesulfone as solvent via Arbuzov type reaction. The effect on inhibiting the formation of osteoclast-like cells (OLC) of related compounds was studied by incubating the extract of rat femur marrow.

RESULTS

Ten compounds of alpha-alkylaminobenzyl phosphonic acids have been synthesized and identified by MS or 1HNMR analysis. Three (2, 8 and 9) of them were found to have notable effect on the inhibition of OLC formation (P < 0.01).

CONCLUSION

Among the present substituted benzyl phosphonic acids, the increased aromaticity and hydrophobicity (such as compound 9) can remarkably enhance the ability to inhibit OLC formation.

Effects of exposure to trinitrotoluene on male reproduction

A cross-sectional study was performed in 2 plants located in Henan Province in 1990 for observing the reproductive and sexual functions of male workers exposed to trinitrotoluene (TNT). The TNT concentrations in the workplace air, except the packing site, were found to have exceeded MAC (1 mg/m3). TNT exposed male workers complained of more sexual disorders such as impotence, the loss of libido and sexual hypoesthesia than the control group. Compared with the control group, the volume of semen and percentage of motile spermatozoa were found to have significantly decreased, and the sperm malformation incidence increased significantly in TNT exposed workers. The serum testosterone content in TNT exposed male workers was significantly decreased too.