Nanotherapy for bone repair: milk-derived small extracellular vesicles delivery of icariin

Icariin (ICA) played an important role in the treatment of inflammatory bone defects. However, pharmacokinetic studies have shown that its poor bioavailability limited its application. In this context, we isolated bovine milk-derived sEV and prepared sEV-ICA to improve the osteogenic effect of ICA. In this study, we successfully constructed sEV-ICA. sEV-ICA was found to have significantly higher osteogenic efficiency than ICA in cell culture and cranial bone defect models. Mechanistically, bioinformatics analysis predicted that signal transducers and activators of transcription 5 (STAT5a) may bind to the GJA1 promoter, while luciferase activity assays and chromatin immunoprecipitation (ChIP) experiments confirmed that STAT5a directly binded to the GJA1 promoter to promote osteogenesis. We proved that compared with ICA, sEV-ICA showed a better effect of promoting bone repair in vivo and in vitro. In addition, sEV-ICA could promote osteogenesis by promoting the combination of STAT5a and GJA1 promoter. In summary, as a complex drug delivery system, sEV-ICA constituted a rapid and effective method for the treatment of bone defects and could improve the osteogenic activity of ICA.

Host response of Nicotiana benthamiana to the parasitism of five populations of root-lesion nematode, Pratylenchus coffeae, from China

In a recent survey of nematodes associated with tobacco in Shandong, China, the root-lesion nematode Pratylenchus coffeae was identified using a combination of morphology and molecular techniques. This nematode species is a serious parasite that damages a variety of plant species. The model plant benthi, Nicotiana benthamiana, is frequently used to study plant-disease interactions. However, it is not known whether this plant species is a host of P. coffeae. The objectives of this study were to evaluate the parasitism and pathogenicity of five populations of the root-lesion nematode P. coffeae on N. benthamiana.N. benthamiana seedlings with the same growth status were chosen and inoculated with 1,000 nematodes per pot. At 60 days after inoculation, the reproductive factors (Rf = final population densities (Pf)/initial population densities (Pi)) for P. coffeae in the rhizosphere of N. benthamiana were all more than 1, suggesting that N. benthamiana was a good host plant for P. coffeae.Nicotiana. benthamiana infected by P. coffeae showed weak growth, decreased tillering, high root reduction, and noticeable brown spots on the roots. Thus, we determined that the model plant N. benthamiana can be used to study plant-P. coffeae interactions.

[Early efficacy and safety of mini open (air/water medium) endoscopy assisted anterior cervical discectomy and fusion in the treatment of cervical spondylotic myelopathy]

Objective: To investigate the efficacy and safety of mini open (air/water medium) endoscopy assisted anterior cervical discectomy and fusion (MOEA-ACDF) for the treatment of cervical spondylotic myelopathy (CSM). Methods: A follow-up study. The clinical data of 30 patients with CSM treated by MOEA-ACDF from January to December in 2021 in the Henan NO.3 Provincial People's Hospital were retrospectively analyzed. Of the patients, 20 were male and 10 were female, the mean age was (49.8±9.3) years (ranged 28-70 years). The CSM occurred at C3-4 level in 2 cases, at C4-5 level in 3 cases, at C5-6 level in 22 cases and at C6-7 level in 3 cases. Each case was compared at the moment of pre-operation and final follow-up by the Japanese Orthopedic Association (JOA) score, C2-7 Cobb angle, and anterior column height of surgical segment. The postoperative complications were recorded. Prevertebral soft tissue edema and hydrops were assessed. The fusion rate was evaluated. The JOA improvement rate was computed at the final follow-up. Results: All the operations were successfully completed and all the patients received follow-up for (12.7±2.7) months (ranged 9-20 months). The mean operation time was (85.3±11.0) min (ranged 65-110 min). The postoperative drainage volume was (16.7±7.4) ml (ranged 5-35 ml). The JOA score and the C2-7 Cobb angle both improved at the final follow-up when compared with those before the operation (15.3±1.3 vs 12.2±2.3, 15.5°±6.1° vs 12.3°±6.0°, both P<0.001). The anterior column height of surgical segment at the final follow-up was (35.6±2.5) mm, and it was higher than that before the operation [(34.1±2.4) mm](P<0.001). No postoperative complications such as dysphagia, hoarseness, cerebrospinal fluid leakage, nerve injury, hematoma occurred. Postoperative review of cervical MRI revealed 3 cases of prevertebral soft tissue edema and hydrops without obvious symptoms. At the final follow-up, cervical spine X-ray or CT showed that all fusion segments met the criteria for osseous fusion, and the fusion rate was 100%. No complications such as neurological aggravation, internal fixation failure, fusion cage sinking, and adjacent segment degeneration was recorded at the final follow-up. At the final follow-up, the comprehensive efficacy evaluated by JOA improvement rate indicated the excellent and good rate was 90.0%(27/30): 19 cases got an excellent outcome, 8 cases got good and 3 cases got medium outcome. Conclusion: MOEA-ACDF combines the endoscopic system with ACDF technology in the treatment of CSM can achieve satisfactory clinical efficacy with high safety, and effectively restore the cervical intervertebral height and physiological curvature.

Milk-Derived Small Extracellular Vesicles Promote Osteogenic Differentiation and Inhibit Inflammation via microRNA-21

Chronic apical periodontitis (CAP) is a disease with characteristics of inflammation and bone loss. In this study, our objective was to examine the function of small extracellular vesicles (sEVs) obtained from milk in encouraging osteogenic differentiation and inhibiting inflammation by miR-21 in CAP. The expression of miR-21 was detected using qRT-PCR in human CAP samples. The impact of miR-21 on the process of osteogenic differentiation was investigated using CCK-8, qRT-PCR, immunofluorescence staining, and Western blot analysis. The evaluation of RAW 264.7 cell polarization and the assessment of inflammatory factor expression were conducted through qRT-PCR. The influence of sEVs on MC3T3-E1 cells and RAW 264.7 cells was examined, with a particular emphasis on the involvement of miR-21. In human CAP samples, a decrease in miR-21 expression was observed. MiR-21 increased the expression of osteogenesis-related genes and M2 polarization genes while decreasing the expression of M1 polarization genes and inflammatory cytokines. Treatment with milk-derived sEVs also promoted osteogenesis and M2 polarization while inhibiting M1 polarization and inflammation. Conversely, the addition of miR-21 inhibitors resulted in opposite effects. Our results indicated that sEVs derived from milk had a positive effect on bone formation and activation of anti-inflammatory (M2) macrophages and simultaneously reduced inflammation by regulating miR-21 in CAP.

microRNAs delivered by small extracellular vesicles in MSCs as an emerging tool for bone regeneration

Bone regeneration is a dynamic process that involves angiogenesis and the balance of osteogenesis and osteoclastogenesis. In bone tissue engineering, the transplantation of mesenchymal stem cells (MSCs) is a promising approach to restore bone homeostasis. MSCs, particularly their small extracellular vesicles (sEVs), exert therapeutic effects due to their paracrine capability. Increasing evidence indicates that microRNAs (miRNAs) delivered by sEVs from MSCs (MSCs-sEVs) can alter gene expression in recipient cells and enhance bone regeneration. As an ideal delivery vehicle of miRNAs, MSCs-sEVs combine the high bioavailability and stability of sEVs with osteogenic ability of miRNAs, which can effectively overcome the challenge of low delivery efficiency in miRNA therapy. In this review, we focus on the recent advancements in the use of miRNAs delivered by MSCs-sEVs for bone regeneration and disorders. Additionally, we summarize the changes in miRNA expression in osteogenic-related MSCs-sEVs under different microenvironments.

[Wine-processed Chuanxiong Rhizoma enhances efficacy of aumolertinib against EGFRmutant non-small cell lung cancer xenografts in nude mouse brain]

OBJECTIVE

To investigate the effect of wine-processed Chuanxiong Rhizoma (WCR) for enhancing the efficacy of aumolertinib against xenografts of epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) in the brain of nude mice.

METHODS

In a co-culture system of hCMEC/D3 and PC9 NSCLC cells, the effect of aqueous extract of WCR (2 mg/mL) combined with aumolertinib (10 and 20 μmol/L) on apoptosis of PC9 cells was investigated using flow cytometry. The effects of WCR extract (0.5, 1, and 2 mg/mL) on transmembrane transport of 8 μmol/L aumolertinib was examined in ABCB1-MDCK monolayer cells. Western blotting was used to detect the expressions of the tight junction proteins related with blood- brain barrier integrity. A nude mouse model bearing NSCLC xenograft in the brain was established to observe the inhibitory effect of WCR (1 mg/g) combined with aumolertinib (10 mg/kg) on tumor growth.

RESULTS

Compared with aumolertinib (20 μmol/L) alone, WCR extract (2 mg/mL) combined with aumolertinib significantly increased the apoptosis rate of PC9 cells by 21% (P < 0.01). The combined treatment with WCR (0.5, 1, 2 mg/mL) obviously increased apical-basolateral transport of aumolertinib in ABCB1-MDCK monolayer cells (P < 0.05) and significantly lowered the expression levels of zonula occludens-1, claudin-5 and P-glycoprotein (P < 0.05). In the tumor-bearing mice, compared with aumolertinib alone, the combined treatment with WCR and aumolertinib produced stronger inhibitory effect on tumor growth, improved weight loss, and prolonged the survival time of the nude mice (P < 0.05). Pathological examination showed that the combined treatment obviously increased the apoptosis rate of the tumor cells and alleviated neural injuries in the brain. Immunohistochemistry revealed that WCR treatment significantly reduced the expressions of ZO-1 and claudin-5 in the brain of the mice.

CONCLUSION

WCR combined with aumolertinib shows stronger inhibitory effects against tumor xenografts of EGFR-mutant NSCLC possibly due to the effect of WCR in facilitating the transmembrane transport of aumolertinib by downregulating ZO-1, claudin-5 and P-glycoprotein expression.

Milk-derived small extracellular vesicles: nanomaterials to promote bone formation

Small extracellular vesicles (sEVs) are an important component in the paracrine pathway. They can be used as a substitute for seed cells and have shown good application prospects in promoting bone regeneration. Cow’s milk could be used as a source of sEVs with good biocompatibility and cost-effectiveness, with easy availability, low cost and low toxicity. This study focused on the role and mechanism of small extracellular vesicles derived from milk in bone repair. In order to explore the mechanism via which Milk-sEVs promote bone repair, we screened the differential gene GJA1 in Milk-sEV-treated osteoblasts through transcriptome chips, and verified the transcript AP3B1 of GJA1 through chromatin immunoprecipitation (CHIP). We have proved by in vivo and in vitro experiments that milk-derived sEVs (Milk-sEVs) increase the repair ability of bone tissue, and promote expression of the osteogenic gene GJA1 through the transcript AP3B1.

[Chuanxiong Rhizoma inhibits brain metastasis of lung cancer through multiple active ingredients acting on multiple targets, pathways and biological functions]

OBJECTIVE

To explore the molecular mechanism mediating the inhibitory effect of Chuanxiong Rhizoma against brain metastasis of lung cancer using network pharmacology methods and molecular docking.

METHODS

The chemical components of Chuanxiong Rhizoma and their targets were obtained through the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database. The relevant targets for brain metastasis of lung cancer were screened using the GeneCards database. Clusterpro-filerR package was used to perform GO and KEGG enrichment analysis. Cytoscape and STRING database were used to construct the "active ingredient-target-disease" network and protein-protein interaction (PPI) network of Chuanxiong Rhizoma. The core components of Chuanxiong Rhizoma and their targets in the treatment of lung cancer brain metastasis were screened based on the topological parameters, and the results were verified using molecular docking and in Chuanxiong extract- treated human lung cancer PC9 cells by detecting the core target with Western blotting.

RESULTS

Forty-eight active ingredients of Chuanxiong Rhizoma including (Z)-ligustilide, butylphthalide, oleic acid, and myricetone were screened, which target 49 proteins including INS, BDNF, FOS, VEGFA, PTGS2, ESR1, MAPK14, and PTGS1. These proteins participated in 57 biological functions such as nuclear receptor activity, ligand activation, and transcription factor activity, involving 40 signaling pathways such as prolactin signaling pathway, breast cancer, and etrogen signaling. The results of molecular docking showed that myricetone, butylphthalide, 4-hydroxy-3 butylphthalide, (Z)-ligustilide, and ligustalide-E, among others, had strong affinities to 7 cores targets including BDNF, FOS, PTGS2, and MAPK14. In PC9 cells, treatment with Chuanxiong Rhizoma extract resulted in significant reductions in the phosphorylation levels of PI3K, Akt and VEGF (P < 0.01).

CONCLUSION

Chuanxiong Rhizoma contains multiple active ingredients against brain metastasis lung cancer, and these ingredients act on multiple targets involving multiple signal pathways and biological functions.

E2F1-induced upregulation of lncRNA HCG18 stimulates proliferation and migration in gastric cancer by binding to miR-197-3p

OBJECTIVE

LncRNA HCG18 is considered to be an oncogene in many types of tumors. The aim of this study was to explore the role of lncRNA HCG18 in gastric cancer (GC).

PATIENTS AND METHODS

HCG18 levels in GC tissues were detected. Potential biological influences of HCG18 on GC cell phenotypes were examined by Cell Counting Kit-8 (CCK-8), wound healing and transwell assay. Subsequently, bioinformatics analysis, Chromatin immunoprecipitation (ChIP), Luciferase assay and rescue experiments were conducted to identify the regulatory network of HCG18 in GC.

RESULTS

It was found that HCG18 was upregulated in GC samples, and the knockdown of HCG18 inhibited proliferative and migratory abilities in GC. The transcription factor E2F1 could directly bind to the promoter region of HCG18 and thus activate its transcription. In addition, HCG18 sponged miR-197-3p to stimulate the malignant development of GC.

CONCLUSIONS

HCG18 is upregulated in GC samples by E2F1 induction, which stimulates proliferative and migratory abilities in GC by binding to miR-197-3p.

FBS-Derived Exosomes as a Natural Nano-Scale Carrier for Icariin Promote Osteoblast Proliferation

Icariin is a class IV drug of low solubility, permeability, and poor bioavailability. Synthetic nanomaterials have developed rapidly. However, some literatures point out that synthetic nanomaterials such as liposomes, aptamers, metal nanoparticles, and nanogels have high toxicity and are affected by the reticuloendothelial system or mononuclear phagocyte system. It is known that exosomes could be used as an ideal clinical drug delivery vehicle to avoid the above-mentioned problems to a certain extent. Studies have shown that drugs can be loaded into exosomes by passive and active loading. We used Fetal bovine serum (FBS) exosomes to carry Icariin for the first time in this experiment, FBS exosomes-Icariin (FBS EXO-ICA) more effectively promoted the proliferation of osteoblasts and bone regeneration than Icariin alone. FBS EXO-ICA could become a new nano scale drug formulation for treating diseases associated with bone loss.

Small extracellular vesicle-bound vascular endothelial growth factor secreted by carcinoma-associated fibroblasts promotes angiogenesis in a bevacizumab-resistant manner

The blood vessel growth inhibitor bevacizumab targets vascular endothelial growth factor (VEGF), a crucial regulator of angiogenesis. Recently, small extracellular vesicles (sEVs) have been demonstrated to be important vehicles in the transport of growth factors to target cells. In this study, we isolated primary carcinoma-associated fibroblasts (CAFs) from four human oral squamous cell carcinoma (OSCC) specimens. Compared with other non-extracellular vesicle components, CAF-derived sEVs were found to be the main regulators of angiogenesis. The ability of CAF sEVs to activate VEGF receptor 2 (VEGFR2) signaling in human umbilical vein endothelial cells (HUVEC) was dependent on the association between sEVs and VEGF. In addition, sEV-bound VEGF secreted by CAFs further activated VEGFR2 signaling in HUVEC in a bevacizumab-resistant manner. VEGF was found to interact with heparan sulfate proteoglycans on the CAF sEV surface and could be released by heparinase I/III. The bioactivity of the dissociated VEGF was retained in vitro and in vivo and could be neutralized by bevacizumab. These findings suggest that the combined use of heparinase and bevacizumab might inhibit angiogenesis in patients with high levels of sEV-bound VEGF.

[Monitoring metrics for short-term exposure to ambient ozone and pulmonary function and airway inflammation in healthy young adults]

OBJECTIVE

To assess the associations of different monitoring metrics for short-term exposure to ambient ozone (O₃) with pulmonary function and airway inflammation in healthy young adults.

METHODS

A total of 97 healthy young college students were recruited and followed in a panel study conducted from December 2017 to June 2018. Each participant underwent 3 follow-up visits, and lung function and fractional exhaled nitric oxide (FeNO) were measured at each visit. Ambient air pollutant concentrations were obtained from the environment monitoring station of Beijing closest to the participant residences, and meteorological data were collected from China Meteorological Data Service Center. Linear mixed-effect models were applied to assess the associations between different monitoring metrics for ambient O₃ short-term exposure with pulmonary function or airway inflammation in the healthy young adults.

RESULTS

During the study period, the P₅₀ (P₂₅, P₇₅) values for ambient O₃ concentration expressed as daily 1-hour maximum (O₃-1 h max), daily maximum 8-hour average (O₃-8 h max) and 24-hour average (O₃-24 h avg) were 102.5 (76.8, 163.0) μg/m³, 91.1 (68.3, 154.3) μg/m³ and 61.6 (36.9, 81.7) μg/m³, respectively. The different monitoring metrics for short-term exposure to ambient O₃ were significantly associated with reduced forced expiratory volume in the first second (FEV₁) and increased FeNO. An interquartile range (IQR) increase in 6-d moving average of O₃-1 h max (IQR=71.5 μg/m³) was associated with a 6.2% (95%CI: －11.8%, －0.5%) decrease in FEV₁ and a 63.3% (95%CI: 13.8%, 134.3%) increase in FeNO. An IQR increase in 7-d moving average of O₃-8 h max (IQR=62.0 μg/m³) was associated with a 6.2% (95%CI: －11.6%, －0.7%) decrease in FEV₁and a 75.5% (95%CI: 19.3%, 158.0%) increase in FeNO. An IQR increase in 5-d moving average of O₃-24 h avg (IQR=32.9 μg/m³) was associated with a 3.7% (95%CI: －7.1%, －0.2%) decrease in FEV₁and a 25.3% (95%CI: 3.6%, 51.6%) increase in FeNO. There was no significant association between the three monitoring metrics for O₃ exposure and peak expiratory flow (PEF).

CONCLUSION

Short-term exposure to ambient O₃ was associated with decreased lung function and increased airway inflammation among the healthy young adults, and daily 1-hour maximum was more sensitively to the respiratory effects of O₃.

Cathepsin C promotes the progression of periapical periodontitis

Although the role of cathepsin C (Cat C) in inflammation is gradually being elucidated, its function in periapical periodontitis, which is one of the most common infectious diseases worldwide, has not been studied. This study evaluated a surgically-induced model of periapical periodontitis in cathepsin C (Cat C) knock-down (KD) mice, which was constructed with a tetracycline operator, to evaluate the role of Cat C in the pathogenesis and progression of periapical periodontitis. Our results showed, for the first time, that there was a statistically significant increase in the expression of Cat C as periapical periodontitis progressed; this increase started from 1 week after surgery and reached a peak at 3 weeks after surgery, before gradually decreasing. The volume of periapical bone resorption in Cat C KD mice was significantly smaller than that in wild-type mice at 3 and 4 weeks after surgery (P<0.05). Inflammatory cell infiltration into the apical tissues of wild-type mice was also significantly higher than that of Cat C KD mice. The expression of receptor activator of nuclear factor-κB ligand (RANKL) in wild-type mice was also higher than that in Cat C KD mice. The difference in the number of osteoclasts in the apical area between the two groups was statistically significant after 2 weeks. Correlation analysis showed that there was a significant correlation between Cat C and RANKL expression (r= 0.835). Therefore, our data indicated that Cat C promoted the apical inflammation and bone destruction in mice.

AB0588 INFECTION AGGRAVATED DECREASE OF THE LEVEL OF TH17 AND TREG CELLS AND LOW-DOSE IL-2 REBALANCED TH17/TREG IN THE PERIPHERAL BLOOD OF PATIENTS WITH IDIOPATHIC INFLAMMATORY MYOPATHY

Background:

Idiopathic inflammatory myopathies (IIM) are featured by a series of clinical presentation such as proximal muscle weakness, increased serum levels of creatine kinase and other muscle enzymes and involvement of other organs and systems[1, 2], which results in high morbidity and early mortality[3]. We have known the changes of the level of Th17 and Treg cells in IIM in previous studies[4-6]. However, whether infection affects lymphocyte subsets or not and whether the effect of low-dose interleukin-2 (IL-2) can be influenced by the use of immunosuppressants or not are still unclear.

Objectives:

The study aimed to explore the changes of lymphocyte subsets in patients of IIM with or without important organ infection, and the restoration of Th17/Treg after receiving low-dose IL-2.

Methods:

A total of 118 IIM patients were enrolled and classified into infection group and non-infection group based on the important organ infection. Of them, 48 cases were treated with low dose IL-2 (5.0*105IU for 5 days). The absolute number of peripheral total T, B, CD4+T, CD8+T, NK, Th1, Th2, Th17 and Treg cell subsets were analyzed by flow cytometry combined with absolute counting beads. Clinical data, laboratory examinations and the levels of peripheral lymphocyte subsets were analyzed retrospectively.

Results:

In these patients, especially in the infection group, the absolute number of T, CD4+T, CD8+T, NK, Th1, Th2, Th17 and Treg cells were significantly decreased as compared with that in the healthy controls, which were significantly increased by low dose IL-2 (especially Treg cells) treatment. The levels of ESR, LDH and HBDH and the ratio of Th17/Treg were significantly lower than those before IL-2 treatment (Z=-2.237, -2.083, -2.140, -3.663,P=0.025, 0.037, 0.032, 0.000). The 48 cases who received IL-2 treatment were divided into 2 groups according to whether they used immunosuppressants. There was no significant difference in the absolute number of T, B, CD4+T, CD8+T, Th1, Th2, Th17 and Treg cells, the proportion of Th17 and Treg cells and the ratio of Th17/Treg between the 2 groups (P>0.05).

Conclusion:

Global decrease in lymphocyte subsets was found in IIM patients, especially those who had important organ infection. A significant re-balance of Th17/Treg was observed after receiving treatment with low-dose IL-2. Furthermore, the restoration of lymphocyte subsets showed similar degree after treatment with or without immunosuppressants. Low-dose IL-2 may become a potential therapy for IIM patients. The mechanism of lymphocyte decrease in IIM is required further to study.

References:

[1]Clark K E N, Isenberg D A. A review of inflammatory idiopathic myopathy focusing on polymyositis[J]. European Journal of Neurology, 2017.

[2]Tieu J, Lundberg IE, Limaye V. Idiopathic inflammatory myositis. Best Pract Res Clin Rheumatol. 2016. 30(1): 149-68.

[3]Mandel DE, Malemud CJ, Askari AD. Idiopathic Inflammatory Myopathies: A Review of the Classification and Impact of Pathogenesis. Int J Mol Sci. 2017. 18(5).

[4]Zhang SX, Wang J, Sun HH, et al. Circulating regulatory T cells were absolutely decreased in dermatomyositis/polymyositis patients and restored by low-dose IL-2. Ann Rheum Dis. 2019 .

[5]Espinosa-Ortega F, Gómez-Martin D, Santana-De Anda K, Romo-Tena J, Villaseñor-Ovies P, Alcocer-Varela J. Quantitative T cell subsets profile in peripheral blood from patients with idiopathic inflammatory myopathies: tilting the balance towards proinflammatory and pro-apoptotic subsets. Clin Exp Immunol. 2015. 179(3): 520-8.

[6]Feng M, Guo H, Zhang C, et al. Absolute reduction of regulatory T cells and regulatory effect of short-term and low-dose IL-2 in polymyositis or dermatomyositis. Int Immunopharmacol. 2019. 77: 105912.

Acknowledgments:

Thanks for the support of my teachers, classmates and my family.

Disclosure of Interests:

None declared

AB0436 CHANGES OF LYMPHOCYTE SUBSETS AND CLINICAL INDEXES IN PERIPHERAL BLOOD OF PATIENTS WITH ANTI-PHOSPHOLIPID SYNDROME

Background:

Anti-phospholipid Syndrome (APS) is a non-inflammatory autoimmune disease, which can be divided into primary and secondary. Changes in lymphocyte numbers in APS are caused by disruption of the immune balance.

Objectives:

The levels of lymphocyte subsets in peripheral blood of patients with anti-phospholipid syndrome were observed and their clinical indexes were analyzed.

Methods:

53 patients with anti-phospholipid syndrome (APS) were collected as the case group and divided into two groups of A, B according to whether primary and 50 health examiners as the healthy control group. The levels of peripheral lymphocyte subsets and laboratory data [erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), platelets (PLT)]levels in the three groups were analyzed. The measurement data is not subject to normal distribution using the Median-Quartile method for statistical description; multiple sample comparisons using the Kruskal-Wallis H test; p <0.05 as the difference is statistically significant.

Results:

(1) The rates of thrombosis and adverse pregnancy in the two case groups were significantly increased. In the two case groups, the ESR and CRP were higher than those in the healthy control group, and the CRP in group A was higher. (2) Compared with the healthy control group, the levels of CD8+T, CD4+T/CD8+T in case A group were increased,while the levels of total T,CD4+T, CD8+T,CD4+T/CD8+T,Th2 and Treg cells were decreased. However,there was no significant difference in Th17 cells level and Th17/Treg ratio compared with the healthy control group.

Conclusion:

APS patients were more prone to have thrombosis, adverse pregnancy and thrombocytopenia. The changes of lymphocyte subsets were seen in peripheral blood, and the primary and secondary had different directions and different degrees of manifestation.However, whether the secondary factors can aggravate the clinical indicators of APS is still unclear.

References:

[1]Simonin Laurent,Pasquier Elisabeth,Leroyer Christophe et al. Lymphocyte Disturbances in Primary Antiphospholipid Syndrome and Application to Venous Thromboembolism Follow-Up.[J].Clin Rev Allergy Immunol, 2017, 53: 14-27.doi:10.1007/s12016-016-8568-1.

Disclosure of Interests:

None declared

Evaluation of the bond strength of chlorhexidine incorporated into the adhesive system composition: A PRISMA guided meta-analysis

Background/purpose

Composite resin is currently the most widely used dental restoration material. Previous studies have demonstrated that the application of Chlorhexidine (CHX) on the dentin surface after acid etching can result in an improvement in the integrity and stability of tooth restoration through time. In order to better understand whether CHX can help improve the stability of the resin-dentin bond strength, in this study, a comprehensive review of the effect of adding CHX to the adhesive system on the stability of immediate and long-term resin-dentin bond strength was conducted.

Materials and methods

This article was written in accordance with the PRISMA Statement and is registered on the International Prospective Register of Systematic Reviews (registration number CRD42018084962). Six electronic databases including PubMed, Embase, Cochrane library, ISI Web of Science, ClinicalTrials.gov and China National Knowledge Infrastructure (CNKI) were searched up to October, 2018. Ten articles were selected from 340 possible eligible articles for meta-analysis, and 41 sets of data were analyzed in the meta-analysis.

Results

The results indicated that the use of 0.1% and 0.2% CHX does not adversely affect the immediate bond strength (p > 0.05), but both 0.1% and 0.2% CHX increased bond strength compared with the control group over 12 months (p < 0.05). However, this trend does not represent a longer period of aging.

Conclusion

In these in vitro clinical trials, CHX incorporated into the bonding systems maintained the stability of bond strength.

Low Bone Turnover Markers in Young and Middle-Aged Male Patients with Type 2 Diabetes Mellitus

Accumulating evidence has supported an increased risk of osteoporotic fracture in postmenopausal women and elderly men diagnosed with diabetes mellitus. However, it is not uncommon for young and middle-aged male patients diagnosed with type 2 diabetes mellitus (T2DM) to suffer from osteopenia or osteoporosis. Few studies focused on this population group are available. The aim of this study is to evaluate bone metabolic status and investigate the influence of T2DM on bone metabolism in 30-50-year-old men. Anthropometric assessment and blood samples were obtained from 160 patients with T2DM and 69 nondiabetic volunteers. Serum parathyroid hormone (PTH) and bone turnover markers (BTMs), including serum procollagen type I N-terminal peptide (PINP), osteocalcin (OC), and β-cross-linked C-telopeptide of type I collagen (β-CTX), were analysed. No significant differences were observed based on age, body mass index, systolic blood pressure, serum calcium, phosphorus, creatinine, total protein, and albumin levels when comparing T2DM and control groups. Fasting blood glucose, HbA1c, triglyceride (TG), total cholesterol, and low-density lipoprotein cholesterol were significantly increased, while high-density lipoprotein cholesterol was significantly decreased in the T2DM group. Compared with controls, diabetic patients showed lower serum PINP, OC, and PTH levels, whereas serum β-CTX levels were similar between the two groups. Moreover, HbA1c levels were positively correlated with PINP and inversely associated with PTH levels. TG levels were negatively correlated with OC or β-CTX levels. Furthermore, multiple linear regression revealed a positive correlation between HbA1c and PINP levels. These results also revealed a negative association between HbA1c and PTH, and between TG and OC levels, even after adjusting for expected confounder factors. Collectively, these findings indicated that young and middle-aged male patients with T2DM showed a lower turnover state resulting from bone formation inhibition. Glucose and lipid metabolic disorders may affect bone formation through different pathways.

A New NLRP3 Inflammasome Inhibitor, Dioscin, Promotes Osteogenesis

Refractory periapical periodontitis, which is a persistent infection after root canal treatment, still has no effective treatment. Its most common pathogen is Enterococcus faecalis. Here, the precursor of phytosteroids, dioscin, is introduced to fight against the inflammation induced by Enterococcus faecalis. The findings suggest that dioscin inhibits the nuclear transport of NF-κB and the expression of reactive oxygen species (ROS) induced by lipoteichoic acid from the Enterococcus faecalis. The decrease in mRNA and protein levels of NLRP3, Caspase-1, and IL-1β is observed in dioscin treated mouse macrophages. In the MC3T3-E1 cells, dioscin also promotes the expression of osteogenic-related factors, ALP, Runx2, and OCN. The increased formation of mineralized nodules after the application of dioscin further indicates that dioscin has the potential to promote osteogenesis. The above results suggest dioscin can be a potential root canal irrigation or root canal sealant for the treatment of refractory apical periodontitis.

The potential effect of Bruton's tyrosine kinase in refractory periapical periodontitis

To determine the expression of Bruton's tyrosine kinase (BTK) in refractory periapical periodontitis and analyze the relationship between BTK and bone resorption in refractory periapical periodontitis. The mechanism of bone resorption is also discussed. The OneArray Plus expression microarray was used to screen for genes related to refractory periapical periodontitis. Real-time PCR was used to detect the expression of BTK in refractory periapical periodontitis tissues. A model of periapical periodontitis was established by sealing E.faecalis into the pulp of rats. To establish a model of E.faecalis LTA infection of osteoclasts, the relationship between BTK and bone destruction during refractory periapical periodontitis was analyzed. OneArray Plus expression microarray results showed that we found that the expression of 1787 genes in the two samples was different. After validating these samples, we found that BTK was closely related to refractory periapical periodontitis. The results showed that the expression of BTK in refractory periapical periodontitis tissues was higher than that in normal tissues. Immunohistochemistry, enzyme histochemistry and real-time PCR showed that the BTK expression curve in the experimental model resembled a reverse V shape from week 1 to week 4. Osteoclasts were cultured in vitro and treated with E. faecalis LTA. The expression of BTK in the E. faecalis model was greater than that in the control group. BTK played an important role in the progression of refractory periapical periodontitis.

microRNA-935 is reduced in non-small cell lung cancer tissue, is linked to poor outcome, and acts on signal transduction mediator E2F7 and the AKT pathway

BACKGROUND

A potential role for microRNA-935 (miR-935) has been identified in several cancers but not in non-small cell lung cancer (NSCLC). We hypothesised changes in miR-935 in NSCLC, and proposed mechanisms that may further explain its role in carcinogenesis.

METHODS

NSCLC tissue and nearby normal tissue was obtained from 101 patients and was probed by qRT-PCR for miR-935 expression. The role of miR-935 and a potential target (signal transduction factor E2F7) was determined in cell lines by a dual luciferase assay. The function of miR-935 was investigated through metabolic activity (MTT) and transwell migration assays. Western blot and immunocytochemical assays examined protein expression level. Growth of miR-935 transfected or untransfected cells was measured via xenograft tumour formation.

RESULTS

miR-935 was reduced in cancer tissue and was related to lymph node metastases, tumour node metastasis status and poor prognosis (all p < 0.02). In vitro, miR-935 suppressed cell proliferation, migration and invasion in NSCLC cells through targeting E2F7. Furthermore, E2F7 was upregulated in NSCLC tissue associated with poor prognosis (p = 0.0203) of NSCLC patients. miR-935 suppressed the epithelial-mesenchymal transition and AKT pathways in NSCLC and inhibited the tumour growth in vivo.

CONCLUSION

Altered miR-935 in lung cancer biopsy tissue may be a diagnostic tool and could direct treatment. Involvement in carcinogenesis is implied by its suppression of the development of NSCLC via targeting E2F7 and inhibiting AKT pathway.

Osteopontin Promotes Bone Destruction in Periapical Periodontitis by Activating the NF-κB Pathway

Background/Aims: Periapical periodontitis is caused by bacterial infection and results in both one destruction and tooth loss. Osteopontin (OPN) is a secreted phosphorylated glycoprotein that participates in bone metabolism. Methods: Thirty-three patients with chronic periapical periodontitis and 10 patients who had undergone the orthodontic removal of healthy tooth tissue (control) at the periodontal ligament were investigated, and an animal model of mouse periapical periodontitis was established for an in vivo analysis. The relationship between OPN and bone destruction during periapical periodontitis was analyzed. Osteoblasts and osteoclasts were cultured in vitro and treated with lipopolysaccharide. An inhibitor of NF-κB was used to pretreat the transfected cells. Results: OPN increased osteoclast proliferation and differentiation, but reduced osteoblasts proliferation and differentiation. OPN activated the NF-κB pathway during periapical periodontitis and accelerated the transfer and phosphorylation of P65 from the cytoplasm to the nucleus. Conclusion: This study demonstrated that OPN played important roles in the progression of periapical periodontitis, and a dual role in bone metabolism during periapical periodontitis, linking osteoclasts and osteoblasts. The underlying mechanism may be related to the NF-κB pathway.

Liraglutide ameliorates palmitate-induced insulin resistance through inhibiting the IRS-1 serine phosphorylation in mouse skeletal muscle cells

OBJECTIVE

A reduction in insulin-stimulated glucose uptake in skeletal muscles is a characteristic of insulin resistance and type 2 diabetes mellitus (T2DM). The glucagon-like peptide (GLP)-1 agonist liraglutide can reduce blood glucose levels in individuals with T2DM. However, its effect on insulin-induced glucose metabolism in the skeletal muscle of insulin resistance is unknown. We investigated the effects and action mechanisms of liraglutide on insulin resistance (IR) in the skeletal muscle cells treatment with palmitic acid (PA).

METHODS

The cell-surface GLUT4myc levels were determined by an antibody-coupled colorimetric assay. The phosphorylation levels of Akt, PI3K(p85α), AS160, IRS1, IKK, and JNK were determined by western blotting. The quantifications of mRNA levels of TNFα, IL-1β, and IL-6 were determined by real-time PCR. Analysis of variance was used for data analysis.

RESULTS

PA elevated not only phosphorylation of JNK, IRS1 serines, and IKKα/β, but also the expression of IL-6, TNFα and IL-1β in C2C12-GLUT4myc cells. PA can reduce phosphorylation of IRS1 tyrosine. These effects of PA were reversed by liraglutide. In addition, liraglutide can reverse PA-decreased insulin-stimulated cell-surface GLUT4 levels, Akt, PI3K(p85α), and AS160 phosphorylation.

CONCLUSIONS

Liraglutide can enhance insulin-induced GLUT4 translocation by inhibiting IRS1 serine phosphorylation in PA-treated muscle cells.

Comparison of oral microbiota in orthodontic patients and healthy individuals

Orthodontic treatments often include dental displacement using a fixed retainer such as braces, which may result in the accumulation of plaque that provides a suitable environment for microorganisms to cause oral infection. So, this study was designed to investigate the microbial diversity among orthodontic patients and healthy individuals.

METHODS

Fifty individuals i.e. 30 orthodontic patients and 20 normal individuals were included in this study. Samples were collected during the midterm of orthodontic treatment (10-12 months). Saliva samples were collected and total DNA was isolated. Polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) with universal primers targeting the V3 region of 16s rRNA was used to study the bacterial diversity among different orthodontic and control groups. After DGGE profile analysis, the predominant product bands from the gel were excised, cloned, and sequenced to confirm the taxonomic identity followed by its quantification by using real-time PCR with gene-specific primers.

RESULTS

Both orthodontic treatment and control groups formed two distinct clustering profiles, but the Shannon-Weaver index (H') indicated greater microbial diversity in the orthodontic group (P = 0.08). Sequence analysis and real-time PCR revealed a greater number of Pseudomonas spp. in the orthodontic group, while there was no significant difference in Streptococcal spp.

CONCLUSION

This study suggested alterations in the oral microbiota following orthodontic treatment would provide diagnostic tools to identify prevalent microbes associated with oral infections that may prove useful for developing future therapies.

Oxidation-induced generation of a mild electrophile for proximity-enhanced protein-protein crosslinking

We report a strategy to introduce a reactive electrophile into proteins through the conversion of a chemically inert group into a bioreactive group in response to an inducer molecule. This strategy was demonstrated by oxidation-induced and proximity-enhanced protein-protein crosslinking in the presence of a large excess of free nucleophile.

Enterococcus faecalis Lipoteichoic Acid-induced NLRP3 Inflammasome via the Activation of the Nuclear Factor Kappa B Pathway

INTRODUCTION

We wished to examine the effects of the nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome on periapical periodontitis induced by Enterococcus faecalis and to investigate the molecular mechanisms of lipoteichoic acid (LTA) derived from E. faecalis on the expression of the NLRP3 inflammasome.

METHODS

A model of periapical periodontitis by sealing E. faecalis into the pulp chambers of rats was established. We then examined the relationship between the expression, location, distribution, and concentration of NLRP3, caspase-1, and interleukin 1β with the inflammatory progression by immunohistochemistry and undertook correlation analyses. RAW264.7 cells were cultured in the absence or presence of LTA together with or without nuclear factor kappa B (NF-κB) inhibitor BAY 11-7082; NLRP3 inflammasome expression was measured by Western blotting, the enzyme-linked immunosorbent assay, and real-time quantitative polymerase chain reaction. An immunofluorescence study was conducted to further detect whether NF-κB can be completely inhibited by BAY 11-7082 or activated by LTA.

RESULTS

An animal model of periapical periodontitis was established successfully. Expression of NLRP3, caspase-1, and interleukin 1β protein was observed in the inflamed area. The expression of these 3 proteins had a significant positive correlation (P < .05). Overall, our results showed that, compared with the negative control group, LTA could directly activate expression of messenger RNA and protein of the NLRP3 inflammasome (P < .05), whereas BAY 11-7082 inhibited it (P < .05).

CONCLUSIONS

Our results suggested that LTA can act as a directly stimulating factor associated with expression of the NLRP3 inflammasome during periapical periodontitis, which is mainly linked with the NF-κB signaling activation pathway.

Risk factors for lymph node metastasis (LNM) in patients with papillary thyroid microcarcinoma (PTMC): role of preoperative ultrasound

Objective This study aimed to investigate the risk factors and clinical value of lymph node metastasis (LNM) and missed central lymph node metastasis (CLNM) using preoperative ultrasound (US) in patients with papillary thyroid microcarcinoma (PTMC). Methods This retrospective study included 521 patients who underwent thyroidectomy for confirmed PTMC based on a final histological examination between January 2014 and June 2015. Based on the presence of LNM, 521 cases were divided into two groups: metastasis (218) and non-metastasis (303). Univariate and multivariate logistic regression analyses were used to analyse the US and clinical characteristics of the primary tumour. Results We defined LNM based on the tumour diameter with an optimal critical value of 0.55 cm using ROC analysis with a sensitivity of 65.6% and specificity of 59.6%. We defined US-missed CLNM based on the optimal critical value of 0.65 cm using diagnostic ROC analysis with a sensitivity of 66.0% and specificity of 73.0%. The odds ratios of significant factors with LNM by US were 10.3 (95% confidence interval [95% CI], 6.2-17.0), 5.3 (95% CI, 3.3-8.7), 2.7 (95% CI, 1.1-6.5), 4.3 (95% CI, 1.7-10.5), 2.5 (95% CI, 1.5-4.1), and 2.7 (95% CI, 1.7-4.4) for extrathyroidal invasion, blood flow, multifocality, tumour diameter greater than 0.55 cm, male sex, and age younger than 47 years, respectively. Conclusions US characteristics, such as extrathyroidal invasion, blood flow, tumour diameter, sex, and age, may improve the efficacy of predicting LNM and facilitating diagnosis of PTMC. Furthermore, tumour invasion to the extracapsular thyroid and a diameter greater than 0.65 cm indicate CLNM.

Clinical application of a microfluidic chip for immunocapture and quantification of circulating exosomes to assist breast cancer diagnosis and molecular classification

Increasing attention has been attracted by exosomes in blood-based diagnosis because cancer cells release more exosomes in serum than normal cells and these exosomes overexpress a certain number of cancer-related biomarkers. However, capture and biomarker analysis of exosomes for clinical application are technically challenging. In this study, we developed a microfluidic chip for immunocapture and quantification of circulating exosomes from small sample volume and applied this device in clinical study. Circulating EpCAM-positive exosomes were measured in 6 cases breast cancer patients and 3 healthy controls to assist diagnosis. A significant increase in the EpCAM-positive exosome level in these patients was detected, compared to healthy controls. Furthermore, we quantified circulating HER2-positive exosomes in 19 cases of breast cancer patients for molecular classification. We demonstrated that the exosomal HER2 expression levels were almost consistent with that in tumor tissues assessed by immunohistochemical staining. The microfluidic chip might provide a new platform to assist breast cancer diagnosis and molecular classification.

Fluorogenic protein labeling using a genetically encoded unstrained alkene

A new fluorogenic bioorthogonal reaction between styrene (an unstrained alkene) and a tetrazine was developed.

We developed a new fluorogenic bioorthogonal reaction that is based on the inverse electron-demand Diels–Alder reaction between styrene (an unstrained alkene) and a simple tetrazine. The reaction forms a new fluorophore with no literature precedent. We have identified an aminoacyl-tRNA synthetase/tRNA pair for the efficient and site-specific incorporation of a styrene-containing amino acid into proteins in response to amber nonsense codon. Fluorogenic labeling of purified proteins and intact proteins in live cells were demonstrated. The fluorogenicity of the styrene–tetrazine reaction can be potentially applied to the study of protein folding and function under physiological conditions with low background fluorescence interference.

E3 Ubiquitin ligase RNF126 regulates the progression of tongue cancer

This study aims to analyze the role of RNF126 in the oncogenesis of tongue cancer. The cell proliferation and viability of human tongue cancer cells, SCC25 and SCC9 cells, were determined by cell counting and MTT assay, respectively. The effect of RNF126 on regulating AKT signaling pathway was analyzed through western blotting. The transplantation tumor model of nude mice was used to evaluate the tumorigenecity of RNF126. Knockdown of RNF126 inhibited the proliferation and viability of SCC9 and SCC25 cells. Inhibition of RNF126 also decreased the activity of AKT1 as well as its downstream molecules. Furthermore, RNF126 regulated the tumor volume on mice model. These data suggested that RNF126 might be related to the progression of tongue cancer through regulating AKT signaling pathway.

miR-141 is involved in BRD7-mediated cell proliferation and tumor formation through suppression of the PTEN/AKT pathway in nasopharyngeal carcinoma

Bromodomain containing 7 (BRD7) was identified as a nuclear transcriptional regulatory factor. BRD7 functions as a tumor suppressor in multiple cancers, including nasopharyngeal carcinoma (NPC). In this study, we reported a novel mechanism of BRD7 in NPC progression. We demonstrated that the expression of miR-141 was remarkably increased in NPC tissues and was negatively correlated with the expression of BRD7 and the survival rate of NPC patients. Decreased expression levels of miR-141, including the primary, the precursor and the mature forms of miR-141, were found in BRD7-overexpressing HEK293, 5-8F and HNE1 cells compared the control cells, while there was no obvious effect on the expression levels of the two critical enzymes Drosha and Dicer. BRD7 can negatively regulate the promoter activity of miR-141, while no obvious binding site of BRD7 was found in the potential promoter region of miR-141. Moreover, ectopic expression of miR-141 can significantly promote cell proliferation and inhibit apoptosis in NPC, and rescuing the expression of miR-141 in BRD7-overexpressing NPC cells could partially reverse the tumor suppressive effect of BRD7 on cell proliferation and tumor growth in vitro and in vivo. Furthermore, the activation of the PTEN/AKT pathway mediated by the overexpression of BRD7 could be inhibited by rescuing the expression of miR-141, which accordingly results in the partial restoration of cell proliferation and tumor growth. Our findings demonstrate that the BRD7/miR-141/PTEN/AKT axis has critical roles in the progression of NPC and provide some promising targets for the diagnosis and treatment of NPC.

A photoactivatable Src homology 2 (SH2) domain

A photoactivatable SH2 domain that can be potentially applied as an optogenetic tool to the photocontrol of phosphotyrosine-associated biological processes.

Virtual classroom helps medical education for both Chinese and foreign students

AIMS

The rapid development of computer and internet technology has a strong influence over one's quality of education within different fields of study. To determine the potential benefits of introducing internet into medical school classes, a pilot study was conducted in three different Chinese medical schools.

MATERIALS AND METHODS

Seven hundred and eight medical school undergraduates, 385 dental school students and 366 foreign students were randomly recruited to complete a self-administered questionnaire. The contents included personal information, current usage of computer and internet, and attitudes towards the computerised teaching methods. Two forum groups were created using instant message software and were randomly assigned to two classes, allowing students to freely ask or discuss questions with the help of their teachers in these two virtual classrooms.

RESULTS

All 1539 questionnaires were accepted and analysed. Although there were some differences between Chinese and foreign undergraduates, both group of students were highly proficient in internet usage and navigation. Overwhelmingly, 88.37% of the students owned a computer and frequently logged onto the internet. Most of them believed that the internet is a helpful adjunct to their studies and held positive attitudes towards computerised teaching. Compared to the classes that were not assigned internet forums, the two experimental classes performed significantly better on the examination.

CONCLUSIONS

Our results suggest that computerised teaching methods have significant potential to assist in learning for both Chinese and foreign medical undergraduates.

Reprogramming the fate of human glioma cells to impede brain tumor development

Malignant gliomas, the most common solid tumors in the central nervous system, are essentially incurable due to their rapid growth and very invasive nature. One potential approach to eradicating glioma cells is to force these cells to undergo terminal differentiation and, in the process, to irreversible postmitotic arrest. Here, we show that neurogenin 2 (NGN2, also known as NEUROG2) synergizes with sex-determining region Y-box 11 (SOX11) to very efficiently convert human glioma cells to terminally differentiated neuron-like cells in both cell culture and adult mouse brains. These cells exhibit neuronal morphology, marker expression, and electrophysiological properties. The conversion process is accompanied by cell cycle exit, which dramatically inhibits glioma cell proliferation and tumor development after orthotopic transplantation. Most importantly, intracranial injection of NGN2- and SOX11-expressing virus into the tumor mass also curtails glioma growth and significantly improves survival of tumor-bearing mice. Taken together, this study shows a simple and highly efficient strategy for reprogramming malignant glioma cells into postmitotic cells, which might be a promising therapeutic approach for brain tumors.

Ca²⁺ signals promote GLUT4 exocytosis and reduce its endocytosis in muscle cells

Elevating cytosolic Ca(2+) stimulates glucose uptake in skeletal muscle, but how Ca(2+) affects intracellular traffic of GLUT4 is unknown. In tissue, changes in Ca(2+) leading to contraction preclude analysis of the impact of individual, Ca(2+)-derived signals. In L6 muscle cells stably expressing GLUT4myc, the Ca(2+) ionophore ionomycin raised cytosolic Ca(2+) and caused a gain in cell surface GLUT4myc. Extra- and intracellular Ca(2+) chelators (EGTA, BAPTA-AM) reversed this response. Ionomycin activated calcium calmodulin kinase II (CaMKII), AMPK, and PKCs, but not Akt. Silencing CaMKIIδ or AMPKα1/α2 partly reduced the ionomycin-induced gain in surface GLUT4myc, as did peptidic or small molecule inhibitors of CaMKII (CN21) and AMPK (Compound C). Compared with the conventional isoenzyme PKC inhibitor Gö6976, the conventional plus novel PKC inhibitor Gö6983 lowered the ionomycin-induced gain in cell surface GLUT4myc. Ionomycin stimulated GLUT4myc exocytosis and inhibited its endocytosis in live cells. siRNA-mediated knockdown of CaMKIIδ or AMPKα1/α2 partly reversed ionomycin-induced GLUT4myc exocytosis but did not prevent its reduced endocytosis. Compared with Gö6976, Gö6983 markedly reversed the slowing of GLUT4myc endocytosis triggered by ionomycin. In summary, rapid Ca(2+) influx into muscle cells accelerates GLUT4myc exocytosis while slowing GLUT4myc endocytosis. CaMKIIδ and AMPK stimulate GLUT4myc exocytosis, whereas novel PKCs reduce endocytosis. These results identify how Ca(2+)-activated signals selectively regulate GLUT4 exocytosis and endocytosis in muscle cells.

Fabrication of micro-optical elements on curved substrates by electrostatic induced lithography

This article reports the fabrication and characterization of polymeric micro-optical elements on curved substrates using electrostatic induced lithography.

Unusual localization and translocation of TRPV4 protein in cultured ventricular myocytes of the neonatal rat

TRPV4 protein forms a Ca²⁺-permeable channel that is sensitive to osmotic and mechanical stimuli and responds to warm temperatures, and expresses widely in various kinds of tissues. As for cardiac myocytes, TRPV4 has been detected only at the mRNA level and there were few reports about subcel-lular localization of the protein. The purpose of the present study was to investigate the expression profile of TRPV4 protein in cultured neonatal rat ventricular myocytes. Using Western blots, immunofluorescence, confocal microscopy and immuno-electron microscopy, we have shown that TRPV4 protein was predominantly located in the nucleus of cultured neonatal myocytes. Furthermore, cardiac myocytes responded to hypotonic stimulation by translocating TRPV4 protein out of the nucleus. The significance and mechanism concerning the unusual distribution and translocation of TRPV4 protein in cardiac myocytes remain to be clarified.

TRPC1 expression and distribution in rat hearts

Transient receptor potential canonical (TRPC) proteins have been identified as a family of plasma membrane calcium-permeable channels. TRPC proteins can be activated by various stimuli and act as cellular sensors in mammals. Stretch-activated ion channels (SACs) have been proposed to underlie cardiac mechano-electric feedback (MEF), although the molecular entity of SAC remains unknown. There is evidence suggesting that transient receptor potential canonical 1 (TRPC1) is a stretch-activated ion channel. As a non-selective cation channel, TRPC1 may cause stretch-induced depolarization and arrhythmia and thus may contribute to the MEF of the heart. In this study, we examined the expression patterns of TRPC1 in detail at both the mRNA and protein levels in rat hearts. We isolated total RNA from the left and right atria, and the left and right ventricles, and detected TRPC1 mRNA in these tissues using reverse-transcriptase polymerase chain reaction (RT-PCR). To study the protein localization and targeting, we performed immunohistochemistry and immunofluorescence labeling with the antibody against TRPC1. TRPC1 was detected in the cardiomyocytes of the ventricle and atrium at both the mRNA and protein levels. The cell membrane and T-tubule showed strong fluorescence labeling in the ventricular myocytes. Purkinje cells, the endothelial cells and smooth muscle cells of the coronary arterioles also displayed TRPC1 labeling. No TRPC1 was detected in fibroblasts. In conclusion, TRPC1 is widely expressed in the rat heart, including in working cells, Purkinje cells and vascular cells, suggesting that it plays an important role in the heart. The specific distribution pattern offered a useful insight into its function in adult rat ventricular cells. Further investigations are needed to clarify the role of TRPC1 in regulating cardiac activity, including cardiac MEF.

[The correlation analysis on Enterococcus faecalis biofilm and clinical manifestation in retreatment of root canal]

OBJECTIVE

To detect the ability of Enterococcus faecalis (E. faecalis) biofilm formation and explore the relationship between E. faecalis biofilm formation ability and clinical manifestation.

METHODS

96 well plate with the establishment of 53 E. faecalis in vitro biofilm model, combined with crystal violet staining, was used to test the biofilm formation ability of the clinical isolates E. faecalis and analyze the relationship between biofilm formation capacity and clinical manifestation.

RESULTS

In total 53 E. faecalis strains, 40 strains(75.47%) had biofilm forming ability. Statistical analysis revealed that the capacities of biofilm formation between E. faecalis isolated from with fistula and without fistula was significantly different (P<0.05).

CONCLUSION

In the retreatment of root canal, the ability of biofilm formation of E. faecalis separated from the teeth without fistula is better than those separated from the teeth with fistula.