[Bioinformatics-based analysis of the effect of general Transcription Factor IIH on prognosis of Prostate cancer]

Objective: To investigate the genetic and expression characteristics of transcription factor IIH (TFIIH) in pre-initiationcomplex in prostate cancer (PCa) and its relationship with prostate cancer progression. Methods: Analyzing the expression characteristics and clinical signification of TFIIH subunits about 495 cases of PCa and 52 cases of adjacent cancer in The Cancer Genome Atlas-Prostate adenocarcinoma (TCGA-PRAD) database. PCa microarray chip was used to verify the correlation between the key factor General Transcription Factor IIH Subunit 4 (GTF2H4) in TFIIH and clinical features. Results: The 495 patients with PCa were (61.01±6.82) years old.The mRNA expression of ERCC3、GTF2H4 and MNAT1 were high in PCa tissues with GS≥8(P<0.05). The expression of GTF2H4 and MNAT1 were relevant to the pathological stages(P<0.05). High expression of GTF2H4 has higher biochemical recurrence (BCR) rate in PCa patients(HR=2.47, 95%CI:1.62-3.77, P<0.001), which has better predictive effect of BCR in PCa patients(The 3rd, 5th, and 7th year AUC all>0.7) than other subunits, and it has been verified in four additional databases. Single-factor Cox regression analysis showed that GTF2H4 were risk factors for BCR (HR=2.470, 95%CI:1.620-3.767, P<0.001) and GTF2H5 were protective factors(HR=0.506,95%CI: 0.336-0.762, P=0.001). The results of immunohistochemical staining showed that the protein expression of GTF2H4 was correlated with the clinical features of PCa patients.The differences of the above results were statistically significant. Conclusion: GTF2H4, the key factor of TFIIH, is highly expressed in PCa and indicates a poor prognosis.

[Applied anatomical characteristics of vascularized iliac muscle flap and its clinical application in repairing oral and maxillofacial defects]

PURPOSE

To investigate the feasibility and safety of the deep circumflex iliac artery (DCIA) derived chimeric flap through the anatomical study of the blood vessels and perforating branches in the ilioinguinal region, and to provide the basis for selecting different DCIA chimeric flap schemes according to the difficulty of surgery, defect conditions and repair needs.

METHODS

Six Chinese adult specimens were dissected by retrograde perfusion of red latex into bilateral femoral arteries. At the same time, the length, diameter and main branch position of DCIA vascular pedicle were measured in 12 lower limb CTAs, and compared with the anatomical data. Six patients with oral tumors accompanied by mandibular defects who were treated in the Department of Oral and Maxillofacial Surgery, Affiliated Stomatological Hospital of Nanjing Medical University from July 2020 to November 2021 were repaired and reconstructed with the chimeric iliac myofascial flap. The postoperative appearance and occlusal function of the recipient area were observed. SPSS 19.0 software package was used for data analysis.

RESULTS

A total of 19 DCIA perforators with an external diameter of ≥ 0.5 mm were found in 12 specimens of ilioinguinal region. These perforators were distributed in the 5 cm×3 cm area, inside the ilium and 5cm behind the anterior superior iliac spine. The length of DCIA vascular pedicle was (6.73±1.06) cm. The measured value of the external diameter of the starting position of the vascular pedicle was (2.55±0.29) mm. The outer diameter of DCIA skin perforator penetrating deep fascia was (1.12±0.14) mm. In the CTA analysis of 12 lower limbs, it was found that the length of DCIA vascular pedicle was (6.98±0.62) cm. The measured diameter at the original position of vascular pedicle was (2.35±0.20) mm. Six cases of mandibular defects were repaired with iliac internal oblique fascia mosaic flap. Six cases of lliac flap survived successfully after operation. Follow up for 6 to 24 months (average 12 months) showed that the mandibular shape and function recovered well, the intraoral myofascial flap became mucosal, and the implanted iliac bone showed no significant volume change on CT after operation. Walking and weight bearing in donor area were basically normal, and no abdominal hernia occurred.

CONCLUSIONS

DCIA and its main branches have a relatively constant course and distribution in the ilioinguinal region. According to the conditions of different defect areas, different tissue types of chimeric flaps based on DCIA can be prepared to meet the repair requirements. The donor site complications can be controlled, and it is an ideal choice to repair mandibular defects.

Metabolomic Analysis Reveals that SPHK1 Promotes Oral Squamous Cell Carcinoma Progression through NF-κB Activation

BACKGROUND

Metabolic disorders are significant in the occurrence and development of malignant tumors. Changes of specific metabolites and metabolic pathways are molecular therapeutic targets. This study aims to determine the metabolic differences between oral squamous cell carcinoma (OSCC) tissues and paired adjacent noncancerous tissues (ANT) through liquid chromatography-mass spectrometry (LC-MS). SPHK1 is a key enzyme in sphingolipid metabolism. This study also investigates the potential role of SPHK1 in OSCC.

MATERIALS AND METHODS

This study used LC-MS to analyze metabolic differences between OSCC tissues and paired ANT. Principal component analysis (PCA) and partial least-squares discriminant analysis (PLS-DA) were applied to explain the significance of phospholipid metabolism pathways in the occurrence and development of OSCC. Through further experiments, we confirmed the oncogenic phenotypes of SPHK1 in vitro and in vivo, including proliferation, migration, and invasion.

RESULTS

The sphingolipid metabolic pathway was significantly activated in OSCC, and the key enzyme SPHK1 was significantly upregulated in oral cancer tissues, predicting poor OSCC prognosis. In this study, SPHK1 overexpression was associated with high-grade malignancy and poor OSCC prognosis. SPHK1 targeted NF-κB by facilitating p65 expression to regulate OSCC tumor progression and promote metastasis.

CONCLUSIONS

This study identified metabolic differences between OSCC and paired ANT, explored the carcinogenic role of overexpressed SPHK1, and revealed the association of SPHK1 with poor OSCC prognosis. SPHK1 targets NF-κB signaling by facilitating p65 expression to regulate tumor progression and promote tumor metastasis, providing potential therapeutic targets for diagnosing and treating oral tumors.

[Anatomical characteristics of profunda artery perforator flap in the posteromedial femoral region and its application in the reconstruction of oral and maxillofacial defects]

Objective: To investigate the anatomical basis for the preparation of the profunda artery perforator flap (PAPF) in the posteromedial femoral region and its application in the reconstruction of oral and maxillofacial defects. Methods: Six lower limbs of Chinese adult cadavers were micro-surgically dissected. CT angiography (CTA) data of bilateral lower limbs of 6 patients was also collected retrospectively. The number, external diameter, pedicle length, and distribution of perforators in the posteromedial femoral region were recorded from the specimens and CTA data. Meanwhile, 10 patients with oral squamous cell carcinoma in the Department of Oral and Maxillofacial Surgery, Affiliated Hospital of Stomatology, Nanjing Medical University from August 2018 to June 2021 were treated with the PAPF. At each follow-up, contour and function of recipient and donor site, as well as swallowing and speech function were evaluated. Results: A total of 19 profunda artery perforator were identified in 6 lower limb specimens. The outer diameter at the beginning of the source artery was (2.34±0.25) mm and the total length of the pedicle was (11.12±1.06) cm. CTA data analysis of 12 legs identified 15 perforators of profunda artery in the posteromedial region. Eleven perforators were septocutaneous, including 2 perforators with a common trunk, while the remaining 4 perforators were musculocutaneous. As for different patterns of perforators (septocutaneous perforators, musculocutaneous perforators and perforators with a common trunk), the longitudinal distance to the pubic tubercle was (19.95±2.43), (21.84±2.54) and (19.48±0.55) cm respectively. The horizontal distance to the posterior edge of gracilis was (3.54±1.10), (3.72±0.30) and (3.85±1.48) cm, respectively. The initial diameters of perforators was (2.4±0.4), (2.6±0.6) and 1.9 mm respectively. Ten cases of the profunda artery perforator flaps survived successfully after operation. The flap sizes ranged from 8 cm×6 cm to 12 cm×7 cm. The patients were evaluated at 1, 3 and 6 months, and with 6 months interval ever since. During the follow-up, the shape of the recipient site was ideal, and the swallowing and language functions were not significantly affected. There was only linear scar in the donor area, and the function of the thigh was basically normal. Conclusions: PAPF possessed a good anatomic stability, suitable vascular pedicle length and diameter, minor influence to the donor area, sufficient amount tissue with good quality. It is an ideal choice for head and neck reconstruction.

In vitro experimental study on the formation of microRNA-34a loaded exosomes and their inhibitory effect in oral squamous cell carcinoma

Studies have shown the inhibitory effect of microRNA-34a on proliferation, migration, and invasion of oral squamous cell carcinoma. However, the lack of a safe and effective delivery system limits the clinical application of microRNA-34a in oral cancer treatment. An exosome is a small extracellular vesicle that mediates intercellular communication by delivering proteins, nucleic acids, and other contents, and functions as a natural drug delivery carrier. Here, we aimed to explore whether exosomes could be used to load microRNA-34a via co-incubation and further used to treat OSCC. Ultracentrifugation was used to obtain exosomes derived from HEK293T cells and the extracted exosomes were analyzed via transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and Western blotting. Subsequently, we loaded cholesterol-modified microRNA-34a into HEK293T cell exosomes by co-incubation. Then, PKH67 and Cy3 co-labeled exo-microRNA-34a were co-incubated with HN6 cells and exosome entry into the HN6 cells was observed using a confocal laser scanning microscope. The cell proliferation, migration, and invasion were assessed by CCK-8 and Transwell assay analysis. SATB2 expression in HN6 cells was analyzed via western blotting. In this study, cholesterol-modified microRNA-34a was loaded into exosomes of HEK293T cells by co-incubation. The microRNA-34a-loaded exosomes were secreted from HEK293T cells and were absorbed by HN6 oral squamous carcinoma cells. Further, microRNA-34a-loaded exosomes led to a significant inhibition of HN6 cell proliferation, migration, and invasion by down regulating SATB2 expression. These results report a new delivery method for microRNA-34a, providing a new approach for the treatment of oral cancer.

Exosomal microRNA-23b-3p promotes tumor angiogenesis and metastasis by targeting PTEN in Salivary adenoid cystic carcinoma

MicroRNA(miR)-23b-3p is known to target various genes that are involved in cancer-related pathways. Exosomes are emerging intercellular communication agents. Exosomes secreted by cancer cells can deliver active molecules to the surrounding stromal cells, thereby influencing the recipient cells and promoting the development of cancers. However, the role of exosomal miR-23b-3p in salivary adenoid cystic carcinoma (SACC) is not yet clear. In this study, we set out to investigate the potential role of cancer-derived exosomal miR-23b-3p-related PTEN in the alteration of angiogenesis and vascular permeability in SACC. We investigated the effect of exosomal miR-23b-3p on the progression of SACC. In vitro experiments indicated that exosomal miR-23b-3p led to an up-regulation of vascular permeability, and reduced expression of tight junction proteins. In addition, exosomal miR-23b-3p also enhanced angiogenesis and migration. Next, the angiogenic effect of exosomal miR-23b-3p was validated in vivo, as it led to an increase in the tumor microvasculature. Furthermore, the growth rate of SACC was faster after injection of exosomes loaded with cholesterol- modified miR-23b-3p in mice. In conclusion, these results revealed that SACC cells-derived exosomes play an important role in promoting angiogenesis and local vascular microleakage of SACC by transporting miR-23b-3p, which suggests that miR-23b-3p in the exosomes may be a potential biomarker for distant metastasis of SACC. This suggests the potential of a novel therapeutic target by delivering anti-miR-23b-3p that focuses on exosomes.

[Application and research progress of digital virtual simulated design in dental esthetic rehabilitation]

In dental esthetic rehabilitation, patients pay great attention to the rehabilitative esthetic effect before teeth preparation, and this is also an important content of doctor-patient communication. Along with the development and combined application of intraoral scan, three-dimensional (3D) face scan, digital design, numerical control machining and 3D printing technology, digital technology is gradually applied to the virtual simulated design before irreversible operation in dental esthetic rehabilitation. Digital technology can be used in dentistry to simulate the esthetic outcome in advance, to assist communication among the dentists, patients and dental technicians, and to realize satisfactory outcome in the final restorations precisely, which, as a result, increases the clinical satisfaction. This review focuses on the application of digital virtual simulated design technology in dental esthetic rehabilitation, analyzes the current research development, deficiency and future prospects, so as to provide guidance for clinical diagnosis and treatment.

Identification of pivotal microRNAs involved in the development and progression of salivary adenoid cystic carcinoma

BACKGROUND

miRNAs and mRNAs have been significantly implicated in tumorigenesis and served as promising prognostic biomarkers for human cancer. Hence, this study was aimed to develop the pivotal miRNA biomarkers-based prognostic signature for salivary adenoid cystic carcinoma.

METHODS

The miRNA and mRNA expression data were integrated from the gene expression omnibus database to study their involvement in salivary adenoid cystic carcinoma development and progression. Gene ontology and kyoto encyclopedia of genes and genomes were conducted to analyze the biological pathways. Reverse transcription-quantitative PCR was used to verify the expression of selected miRNAs in salivary adenoid cystic carcinoma and corresponding normal tissues.

RESULTS

There were 386 differentially expressed genes: 158 upregulated and 228 downregulated genes and 102 differentially expressed miRNAs: 78 upregulated and 24 downregulated miRNAs in the salivary adenoid cystic carcinoma samples. A miRNA-mRNA network containing 11 miRNAs and 199 genes was subsequently constructed. Gene ontology and Kyoto encyclopedia of genes and genomes enrichment analysis revealed that the genes targeted by the 11 miRNAs were mostly involved in tumor-related pathways and processes, such as miRNAs in cancer, focal adhesion, neurotrophin signaling pathway, and the PI3K-Akt signaling pathway. Among them, 4 miRNAs (miR-375, miR-494, miR-34c-5p, and miR-331-3p) were selected to verify by reverse transcription-quantitative PCR in 36 pairs of collected salivary adenoid cystic carcinoma and adjacent nontumor samples. Overall survival analysis revealed that the higher expression of miR-331-3p was significantly associated with a worst overall survival and multivariate Cox regression analysis suggested that hsa-miR-331-3p could be an independent prognostic factor for salivary adenoid cystic carcinoma.

CONCLUSION

Our results revealed that 4-miRNAs signature was a powerful prognostic biomarker for salivary adenoid cystic carcinoma, which provide a basis for exploring deeper mechanisms regarding the progression of salivary adenoid cystic carcinoma, and leading to the development of potential therapeutic strategies.

HOXA9-induced chemerin signals through CMKLR1/AMPK/TXNIP/NLRP3 pathway to induce pyroptosis of trophoblasts and aggravate preeclampsia

BACKGROUND

Up-regulated chemerin correlates with the risk and the severity of preeclampsia. In this study, we examined impacts and underlying mechanisms by which chemerin regulates pyroptosis and trophoblast inflammation.

METHODS

An in vivo preeclampsia model was established in rats and trophoblasts challenged with hypoxia/reoxygenation (H/R) with or without exogenous chemerin were used as the in vitro model. Expressions of homeobox A9 (HOXA9), chemerin, chemerin receptor (the chemokine-like receptor 1 (CMKLR1)), activated AMP-activated protein kinase (AMPK), thioredoxin-interacting protein (TXNIP), and markers related to NOD-like receptor pyrin-containing receptor 3 (NLRP3) inflammasome were examined by Western blot, and in response to AMPK inhibitor, targeting CMKLR1 or HOXA9. Cell viability and death were examined by CCK-8 and Hoechst staining, respectively. Productions of IL-1β and IL-18 in serum or culture medium were measured by ELISA. Transcriptional regulation of HOXA9 on chemerin was examined by combining expressional analysis, chromatin immunoprecipitation, and luciferase reporter assays.

RESULTS

Up-regulations of HOXA9, chemerin, CMKLR1, TXNIP, and NLRP3 inflammasome were observed in both in vivo and in vitro models of preeclampsia, which were associated with increased death of trophoblasts and productions of IL-1β and IL-18. CMKLR1 and activated-AMPK essentially mediated chemerin effects in trophoblasts. HOXA9 directly activated the transcription of chemerin.

CONCLUSIONS

HOXA9 directly activates the transcription of chemerin, which, by activating the AMPK/TXNIP/NLRP3 inflammasome, promotes pyroptosis and inflammation of trophoblasts, and contributes to preeclampsia. Therefore, targeting chemerin signaling may benefit the prevention and/or treatment of preeclampsia.

Sphk1 promotes salivary adenoid cystic carcinoma progression via PI3K/Akt signaling

The progression of salivary adenoid cystic carcinoma (SACC) is closely related to abnormal gene expression. Herein, the role of Sphk1 in SACC was explored. Sphk1 was overexpressed in SACC tissues. In SACC cell lines, Sphk1 induced cell proliferation, inhibited apoptosis, and promoted cell migration. Moreover, Sphk1 overexpression induced up-regulation of the PI3K protein level and AKT phosphorylation level. Rescue assays further showed that activation of the Sphk1 /PI3K/Akt pathway affected various biological functions of SACC cells. Together, these findings suggested that Sphk1 promotes salivary tumorigenesis by activating the PI3K/ Akt pathway, which may provide novel intervention targets for SACC treatment.

Evaluation of autofluorescence visualization system in the delineation of oral squamous cell carcinoma surgical margins

INTRODUCTION

Delineating the margins of Oral squamous cell carcinoma (OSCC) is a critical step for optimaltumor resection. The aim of this study was to evaluate the accuracy of lesion surgical margin identification using autofluorescence visualization.

MATERIALS AND METHODS

Thirty patients with OSCC were included in this study. For each lesion, the fluorescence loss boundary was determined using VELscope before ablative surgical resection (with a 1.5-2cm safety margin) was performed. A total of 126 samples were obtained from 30 surgical specimens, each containing the tissue from the fluorescence loss boundary to surgical margin. The status of each sample was determined by oral pathologists and the staining intensities of Ki-67, E-cadherin, and Vimentin at the fluorescence loss boundary and surgical margin were evaluated by immunohistochemistry.

RESULTS

Fluorescence loss regions were identified in all patients. Of the 126 samples collected, HE staining identified 77 normal epithelia (61.1%), 26 mild dysplasia (20.6%), 17 severe dysplasia (13.4%) and 6 carcinomas in situ (4.9%). A significant correlation was found between the differentiation grade of tumor cells and the pathological status of the surgical marginal specimens (P<0.05). Forty-two of the 126 samples were randomly selected for further immunohistochemical staining. No significant differences were seen in Ki-67, E-cadherin, or Vimentin expression at the fluorescence loss boundary or surgical margin, however, the proteins' expression level was positively correlated with the degree of dysplasia (P<0.01).

CONCLUSION

Autofluorescence visualization has potential as a simple surgical margin setting device for OSCC and may help delineate the superficial area of OSCC with acceptable accuracy. However, when considering the inherent limitations of this system, we suggest that the approach should only be applied under certain conditions, such as when dealing with superficial, well-differentiated lesions.

Chemerin promotes the pathogenesis of preeclampsia by activating CMKLR1/p-Akt/CEBPɑ axis and inducing M1 macrophage polarization

A higher ratio of M1/M2 macrophages and an elevated chemerin level are both related to increased risk of preeclampsia. However, the crosstalk between these two events and their collective contribution to preeclampsia are not well understood. In this study, we assessed the impacts of chemerin chemokine-like receptor 1 (CMKLR1)/p-Akt/CEBPα axis in regulating macrophage polarization and mediating the pathogenic effects of chemerin on preeclampsia. We showed that chemerin, in a dose- and time-dependent manner, stimulated M1 macrophage polarization, inhibited macrophage-induced trophoblast invasion and migration, and suppressed macrophage-mediated angiogenesis. All these chemerin-induced phenotypes are essentially mediated by sequentially CMKLR1, Akt activation, and CEBPα. Mechanistically, CEBPα acted as a transcriptional activator for both IRF8 and chemerin. In vivo, chemerin aggravated preeclampsia, while α-NETA, an inhibitor for CMKLR1, significantly suppressed M1 macrophage polarization and alleviated preeclampsia. In summary, chemerin, by activating CMKLR1/Akt/CEBPα axis, forms a positive feedback loop, promotes M1 macrophage polarization, suppresses trophoblast migration/invasion and angiogenesis, and contributes to preeclampsia. Therefore, targeting chemerin signaling may benefit the prevention and/or treatment of preeclampsia.

[Application of 3D printing technology under three-dimensional reconstruction in mandibular reconstruction]

PURPOSE

To explore the application value of 3D printing technology under three-dimensional reconstruction in mandibular reconstruction.

METHODS

Eighty-four patients with mandibular defect reconstruction were divided into two groups by different operation methods: 3D group(n=42) and control group(n=42). Patients in the control group underwent routine operation, while patients in the experimental(3D) group underwent three-dimensional reconstruction with 3D printing technology. The operation conditions, incidence of complications, recovery of facial features and occlusal relationship were recorded. SPSS 23.0 software package was used for statistical analysis of the data.

RESULTS

The operation time of 3D group was significantly shorter than that of the control group, and the amount of bleeding was significantly less than that of the control group(P<0.05). The recovery rate of facial appearance and occlusal relationship in 3D group was significantly higher than in the control group(95.24% vs 78.57%, P<0.05). Compared with the control group, the movement distance of mandibular points in 3D group was significantly smaller before and after operation(P<0.05). The satisfaction scores of chewing function and pronunciation recovery in the two groups were close(P>0.05), but compared with the control group, the satisfaction scores of appearance recovery in the 3D group were significantly higher(P<0.05).

CONCLUSIONS

3D reconstruction under 3D printing technology can reduce intraoperative bleeding, shorten the operation duration, and achieve good shape recovery with high degree of satisfaction.

[Effect of mi-138 targeting PLD2 gene on proliferation and migration of oral cancer cells]

PURPOSE

To investigate the effect of miR-138 targeting PLD2 gene on proliferation and migration of oral cancer cells.

METHODS

After oral cancer cells were transfected with miR-138, the expression level of microRNA-138 was detected by RT-PCR assay, the proliferation ability was detected by MTT assay, and cell cycle distribution was detected by flow cytometry. Transwell migration assay was used to detect cell migration ability, Western blotting assay was used to detect the expression levels of MMP-9, PLD2 and cyclin D1 in gastric cancer cells. Luciferase assay was used to report the targeting relationship between microRNA-138 and PLD2 gene. SPSS 21.0 software package was used to analyze the data.

RESULTS

After miR-138 was transfected into oral cancer cells, the relative expression level of miR-138 was 4.28±0.16, which was significantly higher than that of blank control and miR-NC group (P<0.05). Luciferase reporter gene assay showed that the relative activity of PLD2 wild plasmid luciferase was significantly lower in oral cancer cells transfected with microRNA-138 than in other groups (P<0.05); The expression level of PLD2 gene in miR-138 group was significantly lower than that in blank control group and miR-NC group (P<0.05). After oral cancer cells were transfected with miR-138, the proliferation ability of oral cancer cells in miR-373 group was significantly lower than that in control group and miR-NC group (P<0.05). Flow cytometry showed that the ratio of G0/G1 phase was (64.39±6.49)% in the group of miR-138, which was significantly higher than that in the blank control group and the group of miR-NC(P<0.05); The ratio of S phase in the group of miR-138 was(13.28±3.16)%, which was significantly lower than that in the blank control group and the group of miR-NC (P<0.05); There was no significant difference in the ratio of G2/M phase among the groups (P>0.05). Transwell experiment showed that the number of migrating cells transfected with miR-138 in oral cancer cells was 138.46±24.37, which was significantly lower than that in blank control group and miR-NC group(P<0.05). Western blotting experiments showed that the relative levels of MMP-9, vimentin and cyclin D1 in the miR-138 group were 0.14±0.04, 0.17±0.02 and 0.15±0.03, respectively, which were significantly lower than those in the blank control group and the miR-NC group(P<0.05).

CONCLUSIONS

miR-138 can target PLD2 gene expression and inhibit the proliferation and migration of oral cancer cells.

MiR-34a inhibits the proliferation, migration, and invasion of oral squamous cell carcinoma by directly targeting SATB2

In various kinds of carcinomas, the special AT-rich sequence-binding protein 2 (SATB2) with its atypical expression promotes the metastasis and progression of the tumor, though in the oral squamous cell carcinoma (OSCC) its inherent mechanism and the status of SATB2 remain unclear. The role played by the SATB2 expression in the OSCC cell lines and tissue samples in the target of miR-34a downstream is the intended endeavor of this study. In te OSCCs the miR-34a expression was determined by quantitative real-time polymerase chain reaction (q-PCR), while the SATB2 expression in the cell lines and tissue samples in OSCC was analyzed with the q-PCR and the western blot. Studies in both in vitro and in vivo of the effects of miR-34a on the initiation of OSCC were conducted. As a direct target of the miR-34a the SATB2 was verified with the luciferase reporter assay. In cases where the miR-34a levels were low, the SATB2 in OSCCs seemed to be overexpressed. Besides, both in the in vitro and in vivo a suppression of migration, invasion, and cell growth was caused by miR-34a by down regulating the SATB2 expression. The SATB2 being a direct target of miR-34a was confirmed by the cotransfection of miR-34a mimics specifically the decrease in the expression of luciferase of SATB2-3'UTR-wt reporter. As a whole, our study confirmed the inhibition of miR-34a in the invasion, proliferation, and migration of the OSCCs, playing a potential tumor suppressor role with SATB2 as its downstream target.

[Activation of GPER inhibts proliferation and autophagy in prostatic epithelial cells]

Objective: To investigate the effect of G protein-coupled estrogen receptor (GPER) on proliferation and autophagy in prostatic epithelial cells. Methods: Cell Counting Kit-8 (CCK8) assay was used to observe the growth of BPH-1 and RWPE-1 cells after treating with or not with estradiol or GPER selective agonist G1. Autophagy was quantified with Western blot and Cyto-ID autophagy detection kit after treating with estradiol, G1 or both G1 and G15 in the same cells. Results: The OD value in estrogen group and G1 group was significantly lower than those in control group (P<0.01). Compared with control group, Western blot and Cyto-ID green reagent staining revealed that the ratio of LC3Ⅱ/LC3Ⅰ and the relative fluorescence intensity of BPH-1 and RWPE-1 cells were decreased in G1 group and estradiol group (P<0.01). Pretreatment with G15 reversed the effect of G1 (P<0.05). Conclusion: The activation of GPER leads to the inhibition of autophagy and cell proliferation.

[Effect of interleukin-6 promoter DNA methylation on the pathogenesis of systemic lupus erythematosus]

Objective: To analyze peripheral blood interleukin-6 (IL-6) promoter DNA methylation status and its clinical significance in patients with systemic lupus erythematosus (SLE). Methods: Blood samples of 41 adult patients with SLE and 20 healthy controls were collected.The methylation status of IL-6 promoter was determined by methylation specific polymerase chain reaction (MSP). The IL-6 expression was detected by real-time PCR.Correlations between IL-6 promoter methylation status and clinical features or laboratory findings in patients with SLE were analyzed. Results: The levels of IL-6 mRNA were significantly higher in peripheral blood of SLE.DNA methylation levels of IL-6 promoter were reduced in SLE patients as compared with healthy controls.The methylation status and expression of IL-6 in peripheral blood reflected the levels in peripheral blood mononuclear cells (PBMCs). Significantly positive correlation was found between IL-6 hypomethylation and renal disorder, as well as hypocomplementemia in patients with SLE. Conclusion: Hypomethylation of interleukin-6 promoter in peripheral blood might be involved in the etiology of SLE.

[Associations of obesity and physical activity with cognition in people aged 50 and above in Shanghai]

Objective: To investigate the associations of obesity and physical activity with cognition in the elderly. Methods: A cross-sectional survey was conducted from October 2009 to June 2010 among people aged ≥50 years selected through multistage random cluster sampling in Shanghai. The subjects' body weight, body height, waist circumference and hip circumference were measured to calculate body mass index (BMI) and waist-hip ratio (WHR), and the data on self-reported physical activity level were collected through questionnaire survey. A comprehensive battery of cognitive tests was conducted to assess subjects' cognitive functions, including verbal recall, forward digit span (FDS), backward digit span (BDS), and verbal fluency (VF). General linear model was used to examine the associations of BMI, WHR and physical activity with cognition. Results: A total of 7 913 participants were included, with a median age of 60 years. Age, sex, education level, income level, BMI, WHR and physical activity level were significantly associated with cognitive scores in univariate analysis. After adjusted for age, sex, education level and income level, BMI was no longer significantly associated with cognitive scores in all cognitive functions (all P>0.01). WHR was significantly associated with VF score (P<0.01). Abdominally obese participants had lower VF score than non-abdominally obese participants (P<0.01). Physical activity level was significantly associated with all cognitive functions (P<0.01). Compared with participants with moderate physical activity level, participants with low physical activity level had lower scores in all cognitive functions (P<0.01). Conclusion: Abdominal obesity and low physical activity level were negatively associated with cognition level in the elderly, suggesting that waist circumference control and physical activity might help maintain cognition in the elderly.

[The impact of weight management and related diuretic medication intervention based on body weight changes on cardiac function and re-hospitalization rate in patients with chronic congestive heart failure]

Objective: To explore the impact of weight management and related medication intervention based on body weight changes on cardiac function among patients with chronic congestive heart failure (CHF). Methods: Using prospective, randomized, controlled study methods, consecutive CHF patients, who hospitalized in our department from June 2014 to June 2016 (n=350), were randomly divided into intervention group (n=175) and control group (n=175). Patients in the intervention group received weight management guidance and the post discharge diuretic drugs regimen was adjusted based on body weight changes. The control group received routine medical care post discharge. Left ventricular ejection fraction (LVEF), B type natriuretic peptide precursor (NT-proBNP), 6 minutes walk distance and NYHA classification at one day before discharge and after 6 months were compared between the two groups respectively. Results: Follow-up visit data were not available from 6 patients in the control and intervention group respectively. NYHA classification, LVEF, NT-proBNP and 6 minutes walk distance were similar between the two groups at one day before discharge (all P>0.05). After 6 months, the LVEF and 6 minutes walk distance were significantly higher while NT-proBNP level was significantly lower in the intervention group compared to the control group (all P<0.01). Meanwhile, the LVEF and 6 minutes walk distance were significantly increased, while NT-proBNP was significantly reduced at 6 months post discharge compared to one day before discharge in the intervention group (all P<0.01). The LVEF was also significantly improved (P=0.035), but the NT-proBNP and 6 minutes walk distance were similar (P were 0.328 and 0.807 respectively) at 6 months after discharge compared to one day before discharge in the control group. The NYHA classification was significantly lower in intervention group and in control group at 6 months after discharge compared to one day before discharge (Z=5.154, P<0.01 and Z=10.497, P<0.01), and the NYHA classification improved more in the intervention group than in control group at 6 months after discharge (Z=9.235, P<0.01). The re-hospitalization rate of CHF patients in intervention group was 11.83% (20/169), which was significantly lower than the control group (33.14% (56/169), χ(2)=21.99, P<0.01). At 6 months follow up, body weight remained unchanged in the intervention group, while body weight tended to be higher in the control group compared to one day before discharge. Conclusion: The weight management and diuretic drug regimen adjudgment intervention based on body weight changes can improve cardiac function and reduced re-hospitalization rate in CHF patients.

[Expression and correlation of HPV16E6 and tumor suppressor gene p53 in oral squamous cell carcinoma]

PURPOSE

To exploring the expression of PV16E6 gene and p53 gene in patients with oral carcinoma and the correlation between pathological grade and clinical stage of oral cancer and expression of HPV16E6 gene and p53 gene.

METHODS

One hundred and seventy-three cases of oral cancer, 98 cases of oral precancerous lesions and 79 cases of peri-cancerous normal tissue were selected. The expression of HPV16E6 and p53 was detected by immunohistochemistry. The data were analyzed using SPSS 21.0 software package.

RESULTS

In oral carcinoma, the expression rate of HPV16E6 was 81.5% (141/173), the expression rate of p53 was 23.7% (41/173); in oral precancerous lesions, the expression rate of HPV16E6 was 39.8% (39/98), the expression rate of p53 was 57.1% (56/98); in peri-cancerous normal tissues, the expression rate of HPV16E6 was 2.5%(2/79), the positive expression rate of p53 was 89.9%(71/79). There was significant difference in the positive expression rate of p53 and HPV16E6 among 3 groups. The expression of HPV16E6 in oral cancer was significantly higher than in the other two groups(P<0.05); the expression rate of p53 in oral cancer was significantly lower than the other two groups. In addition, with the advance of clinical stage and pathological grade, the positive expression rate of HPV16E6 increased gradually, while the positive expression rate of p53 was significantly decreased (P<0.05).

CONCLUSIONS

HPV16E6 protein and p53 protein may play an important role in the occurrence and progress of oral cancer.

In Situ Release of VEGF Enhances Osteogenesis in 3D Porous Scaffolds Engineered with Osterix-Modified Adipose-Derived Stem Cells

Adipose-derived stem cells (ADSCs) can differentiate into various cell types and thus have great potential for regenerative medicine. Herein, rat ADSCs were isolated; transduced with lentiviruses expressing Osterix (Osx), a transcriptional factor essential for osteogenesis. Osx overexpression upregulated key osteogenesis-related genes, such as special AT-rich binding protein 2, alkaline phosphatase, osteocalcin, and osteopontin, at both mRNA and protein levels. In addition, mineral nodule formation and alkaline phosphatase activity were enhanced in Osx-overexpressing ADSCs. The expression of dickkopf-related protein 1, a potent Wnt signaling pathway inhibitor, was also increased, whereas that of β-catenin, an intracellular signal transducer in the Wnt pathway, was decreased. β-catenin expression was partially recovered by treatment with lithium chloride, a canonical Wnt pathway activator. The Osx-expressing ADSCs were then combined with 3D gelatin-coated porous poly(ɛ-caprolactone) scaffolds with a unique release prolife of entrapped recombinant human vascular endothelial growth factor (VEGF). The controlled release of VEGF promoted osteogenic differentiation capacity in vitro. When the scaffold-ADSC complexes were transplanted into rat calvarial critical-sized defects, more bone formed on the gelatin/VEGF-coated scaffolds than on other scaffold types. Taken together, the results indicate that, Osx-overexpression promotes ADSCs' osteogenesis both in vitro and in vivo, which could be enhanced by release of VEGF.

The overexpressed functional transient receptor potential channel TRPM2 in oral squamous cell carcinoma

TRPM2, one member of the transient receptor potential (TRP) protein super-family, is a Ca²⁺-permeable channel that is activated by oxidative stress and confers susceptibility to cell death. In the human tongue specimens of carcinoma and the tongue carcinoma SCC cell lines, we observed the enhanced expression of TRPM2. By means of the whole-cell electrophysiological recording, the ADPR-induced currents mediated by TRPM2 were recorded in cultured SCC9 cells. Moreover, after H₂O₂ treatment for 24 hours, the apoptotic number of SCC9 cells was significantly increased. However, the selectively knocked-down TRPM2 with the small interfering RNA technique inhibited the survival and migration of the SCC9 cancer cells, which was independent of the p53-p21 pathway, since the expression of p21 was enhanced after TRPM2 knockdown. Furthermore, the sub-cellular localization of TRPM2 was remarkably different between cancerous and non-cancerous cells. A significant amount of the TRPM2 proteins were located in the nuclei in cancer cells. All these data suggest that TRPM2 is essential for the survival and migration of SCC cancer cells and may be a potential target for the selective treatment of tongue cancer.

Membrane Type 1 Matrix Metalloproteinase induces an epithelial to mesenchymal transition and cancer stem cell-like properties in SCC9 cells

BACKGROUND

Tissue invasion and metastasis are acquired abilities of cancer and related to the death in oral squamous cell carcinoma (OSCC). Emerging observations indicate that the epithelial-to-mesenchymal transition (EMT) is associated with tumor progression and the generation of cells with cancer stem cells (CSCs) properties. Membrane Type 1 Matrix Metalloproteinase (MT1-MMP) is a cell surface proteinase, which is involved in degrading extracellular matrix components that can promote tumor invasion and cell migration.

METHODS

In the current study, we utilized SCC9 cells stably transfected with an empty vector (SCC9-N) or a vector encoding human MT1-MMP (SCC9-M) to study the role of MT1-MMP in EMT development.

RESULTS

Upon up-regulation of MT1-MMP, SCC9-M cells underwent EMT, in which they presented a fibroblast-like phenotype and had a decreased expression of epithelial markers (E-cadherin, cytokeratin18 and β-catenin) and an increased expression of mesenchymal markers (vimentin and fibronectin). We further demonstrated that MT1-MMP-induced morphologic changes increased the level of Twist and ZEB, and were dependent on repressing the transcription of E-cadherin. These activities resulted in low adhesive, high invasive abilities of the SCC9-M cells. Furthermore, MT1-MMP-induced transformed cells exhibited cancer stem cell (CSC)-like characteristics, such as low proliferation, self-renewal ability, resistance to chemotherapeutic drugs and apoptosis, and expression of CSCs surface markers.

CONCLUSIONS

In conclusion, our study indicates that overexpression of MT1-MMP induces EMT and results in the acquisition of CSC-like properties in SCC9 cells. Our growing understanding of the mechanism regulating EMT may provide new targets against invasion and metastasis in OSCC.

Axonal regeneration by chronically injured supraspinal neurons can be enhanced by exposure to insulin-like growth factor, basic fibroblast growth factor or transforming growth factor beta

To test whether known growth factors could promote the regenerative reponse of chronically injured neurons, we exposed the injured adult rat spinal cord to insulin-like growth factor 1 (IGF-1), basic fibroblast growth factor (bFGF) or transforming growth factor beta 1 + 2 (TGFβs) 1 month after creation of a hemisection lesion. At 1 week later an autologous peripheral nerve graft was apposed to the rostral cavity wall and 1 month later Nuclear Yellow (NY) was used to retrogradely label neurons that had grown an axon into the graft. Neurons capable of axonal regeneration after a long term (5 weeks) injury were double labeled with True Blue (TB, provided at the time of hemisection lesion) and NY. Exposure to any of the three growth factors, compared to a PBS-treated control, resulted in a significant increase in the total number of regenerating supraspinal neurons, with the greatest increase after treatment with TGFβs. Treatment with TGFβs or bFGF led to a significant increase in the number of regenerating neurons in 6 out of 7 major regions (excluding the motor cortex) contributing to descending spinal pathways. Treatment with IGF-1 promoted significant regeneration only by reticular formation neurons. These results indicate that exposure to specific growth factors can enhance axonal regeneration by chronically injured neurons, thus overcoming one significant challenge to the repair of long standing structural damage to the spinal cord. © 1996 Elsevier Science Ireland Ltd. All rights reserved.

Snail overexpression induces an epithelial to mesenchymal transition and cancer stem cell-like properties in SCC9 cells

Local invasiveness and distant metastasis are critical factors that contribute to oral squamous cell carcinoma-related deaths. Increasing evidence has shown that the epithelial to mesenchymal transition (EMT) is involved in cancer progression and is associated with the 'stemness' of cancer cells. Snail is a transcriptional factor that can induce EMT and preserve stem-cell function, which may induce resistance to radio- and chemotherapies in the cells. In the present study, SCC9 cells were transfected with an empty vector or a vector encoding human Snail (SCC9-S). Overexpression of Snail induced SCC9 cells to undergo EMT, in which the cells presented a fibroblast-like appearance, downregulated the epithelial markers E-cadherin and β-catenin, upregulated the mesenchymal marker vimentin, and associated with highly invasive and metastatic properties. Furthermore, the induction of EMT promoted cancer stem cell (CSC)-like characteristics in the SCC9-S cells, such as low proliferation, self-renewal, and CSC-like markers expression. These results indicate that overexpression of Snail induces EMT and promotes CSC-like traits in the SCC9 cells. Further understanding the role of Snail in cancer progression may reveal new targets for the prevention or therapy of oral cancers.

Single sevoflurane exposure decreases neuronal nitric oxide synthase levels in the hippocampus of developing rats

BACKGROUND

The use of general anaesthetics in young children and infants has raised concerns regarding the adverse effects of these drugs on brain development. Sevoflurane might have harmful effects on the developing brain; however, these effects have not been well investigated.

METHODS

Postnatal day 7 (P7) Sprague-Dawley rats were continuously exposed to 2.3% sevoflurane for 6 h. We used the Fox battery test and Morris water maze (MWM) to examine subsequent neurobehavioural performance. Cleaved caspase-3 and neuronal nitric oxide synthase (nNOS) were quantified by immunoblotting, and the Nissl staining was used to observe the histopathological changes in the hippocampus.

RESULTS

A single 6 h sevoflurane exposure at P7 rats resulted in increased cleaved caspase-3 expression and decreased nNOS levels in the hippocampus, and induced the loss of pyramidal neurones in the CA1 and CA3 subfields of the hippocampus at P7-8. These changes were accompanied by temporal retardation of sensorimotor reflexes. However, neither the Fox battery test at P1-21 nor the MWM test at P28-32 showed differences between the air- and sevoflurane-treated groups.

CONCLUSIONS

Although early exposure to sevoflurane increases activated caspase-3 expression and neuronal loss and decreases nNOS in the neonatal hippocampus, it does not affect subsequent neurobehavioural performances in juvenile rats.

Enhanced osseointegration of titanium implant through the local delivery of transcription factor SATB2

Titanium implants are widely used in dentistry and orthopedic surgery. Nevertheless, bone regeneration around the implant is a relatively slow process, after placement. This study assessed whether SATB2 can enhance osseointegration of a titanium implant. To determine the effect of SATB2 in implant integration, two different viruses encoding SATB2 (PBABE-Satb2 virus or RCAS-Satb2 virus) were locally administered to the bone defect prior to titanium implant placement in our established transgenic TVA mice. Seven and 21 days post implantation, the femurs were isolated for quantitative real-time RT-PCR, H&E staining, immunohistochemical (IHC) staining, and microcomputed tomography (microCT) analysis. Quantitative real-time RT-PCR results demonstrated that the in vivo overexpression of SATB2 enhanced expression levels of potent osteogenic transcription factors and bone matrix proteins. We also found that 21 days after implantation, there were no significant differences in the expression levels of SATB2, Osx, Runx2, COLI, OC, and BSP between the RCAS-Satb2 group and the RCAS group. Histological analysis showed that SATB2 overexpression significantly enhanced new bone formation and bone-to-implant contact after implantation. IHC staining analysis revealed that forced expression of SATB2 increased the number of BSP-positive cells surrounding the implant. MicroCT analysis demonstrated that in vivo overexpression of SATB2 significantly increased the density of the newly formed bone surrounding the implant. These results conclude that in vivo overexpression of SATB2 significantly accelerates osseointegration of titanium implants and SATB2 can serve as a potent molecule in promoting tissue regeneration.

Critical-size calvarial bone defects healing in a mouse model with silk scaffolds and SATB2-modified iPSCs

Induced pluripotent stem cells (iPSCs) can differentiate into mineralizing cells and thus have a great potential in application in engineered bone substitutes with bioactive scaffolds in regeneration medicine. In the current study we characterized and demonstrated the pluripotency and osteogenic differentiation of mouse iPSCs. To enhance the osteogenic differentiation of iPSCs, we then transduced the iPSCs with the potent transcription factor, nuclear matrix protein SATB2. We observed that in SATB2-overexpressing iPSCs there were increased mineral nodule formation and elevated mRNA levels of key osteogenic genes, osterix (OSX), Runx2, bone sialoprotein (BSP) and osteocalcin (OCN). Moreover, the mRNA levels of HoxA2 was reduced after SATB2 overexpression in iPSCs. The SATB2-overexpressing iPSCs were then combined with silk scaffolds and transplanted into critical-size calvarial bone defects created in nude mice. Five weeks post-surgery, radiological and micro-CT analysis revealed enhanced new bone formation in calvarial defects in SATB2 group. Histological analysis also showed increased new bone formation and mineralization in the SATB2 group. In conclusion, the results demonstrate that SATB2 facilitates the differentiation of iPSCs towards osteoblast-lineage cells by repressing HoxA2 and augmenting the functions of the osteoblast determinants Runx2, BSP and OCN.

Using tea stalk lignocellulose as an adsorbent for separating decaffeinated tea catechins

Lignocelluloses prepared from woody tea stalk, pine sawdust and sugarcane bagasse were used as adsorbents to isolate decaffeinated catechins from tea extracts and compared with synthetic macroporous resin HPD 600. HPD 600 had the highest adsorption capacity to catechins, followed by tea stalk lignocellulose while lignocelluloses of pine sawdust and bagasse the least. Tea stalk lignocellulose absorbed preferentially tea catechins and showed a good selectivity. HPD 600 absorbed caffeine and tea catechins simultaneously. The kinetics data of tea stalk lignocellulose showed a good fit with the Langmuir isotherm model. It is considered that tea stalk lignocellulose is an alternative low-cost adsorbent for preparing decaffeinated tea catechins.

The slow wave component of retinal activity in rd/rd mice recorded with a multi-electrode array

We investigated the differences in the retinal activity between normal and degenerate retina. Multi-electrode recordings were performed in in vitro mice retinas. Only short duration (<2 ms) retinal spikes were recorded in normal mice by postnatal day 28. However, in rd/rd mice, a slow wave component with approximately 100 ms duration was also recorded along with the spikes. We attempted to understand the mechanism of this slow wave component in degenerate retina by applying various synaptic blockers. With CNQX/AP-7, the glutamate antagonist (n = 7), the slow wave component disappeared while the normally less-dominant retinal spikes became more apparent. With strychnine, the glycine antagonist (n = 3) or picrotoxin, GABA antagonist (n = 3), the amplitude of the slow wave component increased. These suggest that a stronger excitatory glutamate input from bipolar cells to ganglion cells is the main contributor to this slow wave component in rd/rd mice.

Identification of acid-sensing ion channels in adenoid cystic carcinomas

Tissue acidosis is an important feature of tumor. The response of adenoid cystic carcinoma (ACC) cells to acidic solution was studied using whole-cell patch-clamp recording in the current study. An inward, amiloride-sensitive Na(+) current was identified in cultured ACC-2 cells while not in normal human salivary gland epithelial cells. Electrophysiological and pharmacological properties of the currents suggest that heteromeric acid-sensing ion channels (ASICs) containing 2a and 3 may be responsible for the proton-induced currents in the majority of ACC-2 cells. Consistent with it, analyses of RT-PCR and Western blotting demonstrated the presences of ASIC2a and 3 in ACC-2 cells. Furthermore, we observed the enhanced expression of ASIC2a and 3 in the sample of ACC tissues. These results indicate that the functional expression of ASICs is characteristic feature of ACC cells.

Genistein directly blocks glycine receptors of rat neurons freshly isolated from the ventral tegmental area

The effects of tyrosine kinase inhibitors on the glycine-induced current (I(Gly)) were studied in rat neurons freshly isolated from the ventral tegmental area (VTA). Genistein reversibly and concentration-dependently depressed I(Gly), with an IC(50) of 13 microM. Preincubation with genistein had no effect on I(Gly), indicating that genistein is effective only when glycine is bound to the receptor and channels are most likely open. Genistein depressed maximum I(Gly) without significantly changing the EC(50) for glycine. Genistein-induced inhibition of I(Gly) was sensitive to membrane voltage, being greater at positive membrane potentials. A kinetic analysis indicated that genistein lengthens the time constant of I(Gly) activation, but has no effect on deactivation or desensitization. When genistein was rapidly washed out, a transient rebound current probably reflected a faster dissociation of genistein, with respect to glycine. Results of competition experiments suggest that genistein acts on the same region of the glycine receptor as picrotoxin. Daidzein, an analog of genistein that does not act on protein kinases, also inhibited I(Gly). Co-application of lavendustin A, a specific inhibitor of tyrosine kinase, had no effect on I(Gly). Our results extend to neurons isolated from the VTA, the previous finding that genistein directly inhibits glycine receptors of hypothalamic brain slices.

Decay of ethanol-induced suppression of glycine-activated current of ventral tegmental area neurons

We demonstrated previously that ethanol depresses glycine-induced currents in 45% of neurons freshly isolated from the ventral tegmental area (VTA) of rats (), and that protein kinase C (PKC) modulates this action of ethanol (). In the present study, we investigated the time course of this effect of ethanol on VTA neurons from young rats. For 70% of the neurons in which ethanol reduced glycine-evoked currents, this depressant effect gradually diminished during continuous superfusion with ethanol. Its action decayed faster when ethanol was applied in several brief pulses than by continuous superfusion. On the other hand, the decay was especially slower when ethanol was applied in pulses at longer intervals or by preincubation. Phorbol ester 12,13-dibutyrate (PDBu, 1 microM), an activator of PKC, also depressed glycine-induced currents. In approximately 40% (6/15) of the neurons, the effect of PDBu diminished with time and was antagonized by the specific PKC inhibitor, chelerythrine (7 microM). Chelerythrine also attenuated the ethanol-induced depression of glycine-induced currents and its time-dependent decay, thus confirming our previous evidence that PKC mediates, at least in part, the decay of the depressant effect of ethanol on glycine-induced currents of VTA neurons.

Ethanol inhibition of glycine-activated responses in neurons of ventral tegmental area of neonatal rats

The brain is particularly sensitive to alcohol during the period of its rapid growth. To better understand the mechanism(s) involved, we studied ethanol effects on glycine-activated responses of ventral tegmental area (VTA) neurons isolated from the newborn rat, using whole cell and gramicidin perforated patch-clamp techniques. Previously we reported that 0.1-40 mM ethanol enhances glycine-induced responses of 35% of VTA neurons. We now direct our attention to the inhibitory effects of ethanol observed in 45% (312 of 694) of neonatal VTA neurons. Under current-clamp conditions, 1 mM ethanol had no effect on the membrane potential of these cells, but it decreased glycine-induced membrane depolarization and the frequency of spontaneous action potentials. Under voltage-clamp conditions, 0.1-10 mM ethanol did not elicit a current but depressed the glycine-induced currents. The ethanol-induced inhibition of glycine current was independent of membrane potential (between -60 and +60 mV). Likewise, ethanol did not alter the reversal potential of the glycine-activated currents. Ethanol-mediated inhibition of glycine current depended on the glycine concentration. While ethanol strongly depressed currents activated by 30 microM glycine, it had no appreciable effect on maximal currents activated by 1 mM glycine. In the presence of ethanol (1 mM), the EC(50) for glycine increased from 32 +/- 5 to 60 +/- 3 microM. Thus ethanol may decrease the agonist affinity of glycine receptors. A kinetic analysis indicated that ethanol shortens the time constant of glycine current deactivation but has no effect on activation. In conclusion, by altering VTA neuronal function, ethanol-induced changes in glycine receptors may contribute to neurobehavioral manifestations of the fetal alcohol syndrome.

Ondansetron: a selective 5-HT(3) receptor antagonist and its applications in CNS-related disorders

Ondansetron is a selective 5-hydroxytryptamine(3) (5-HT(3)) receptor antagonist that has been introduced to clinical practice as an antiemetic for cancer treatment-induced and anesthesia-related nausea and vomiting. Its use under these circumstances is both prophylactic and therapeutic. It has a superior efficacy, safety and pharmacoeconomic profile compared with other groups of antiemetics, namely antidopaminergics, antihistamines and anticholinergics. However, its place in the management of anticipatory and delayed vomiting in cancer treatment and as a rescue antiemetic in surgical patients needs to be further explored. Furthermore, recent animal and human research also reflects its possible novel application in the treatment of other disease states, such as alcoholism, cocaine addiction, opioid withdrawal syndrome, anxiety disorders, gastrointestinal motility disorders, Tourette's syndrome and pruritus. This review revisits the widespread physiological and pathological effects of 5-HT and discusses both the basic science literature and the clinical developments responsible for the conventional and novel uses of ondansetron. In addition, new discoveries relating to the effects of ondansetron on other receptors/channels and their possible therapeutic applications are presented.

Interleukin-2 modulates N-methyl-D-aspartate receptors of native mesolimbic neurons

Interleukin (IL)-2 is a brain-derived cytokine that influences mesocorticolimbic dopamine release, and is associated with pathological outcomes that are mediated, at least in part, by aberrations in mesolimbic neurotransmission. The mechanisms by which IL-2 modulates mesolimbic transmission, however, are not known. The NMDA receptor/channel (NMDAR) plays an essential role in neuronal excitability of mesolimbic neurons; we thus examined in neonatal rats the effects of IL-2 on NMDA-activated current (I(NMDA)) in voltage-clamped neurons freshly isolated from the ventral tegmental area (VTA), the site of origin of the mesolimbic system. IL-2 (0.01-500 ng/ml) alone had no effect on membrane conductance. When co-applied with NMDA, IL-2 (50-500 ng/ml) significantly potentiated I(NMDA). In contrast, doses as low as 0.01 ng/ml markedly decreased the NMDA response. Dose-response analysis showed that IL-2 ( > 50 ng/ml) increased the maximal I(NMDA), without changing the EC(50), indicating that IL-2 potentiates I(NMDA) by increasing the efficacy of the NMDAR. Moreover, current-voltage analysis revealed that IL-2 potentiation of I(NMDA) was voltage-dependent, being greater at negative potentials. In contrast, IL-2 inhibition of I(NMDA) was voltage-independent, and IL-2 did not alter the reversal potential. Additionally, IL-2 (1 ng/ml) shifted the NMDA concentration-response curve to the right, significantly increasing the EC(50) for NMDA without changing the maximal I(NMDA), suggesting that IL-2 inhibits the NMDAR by a competitive mechanism. IL-2 thus acts as a potent modulator of the NMDAR. IL-2-induced alterations of responses to NMDAR activation may contribute to synaptic plasticity in the mesolimbic system and to pathological outcomes associated with this system.

Ethanol potentiation of glycine-induced responses in dissociated neurons of rat ventral tegmental area

The potentiation of glycine-induced responses by ethanol (EtOH) was studied in neurons freshly dissociated from the ventral tegmental area (VTA) of 5- to 14-day-old postnatal rats using whole-cell and gramicidin-perforated patch-clamp techniques. Under current-clamp conditions, EtOH increased glycine-induced membrane depolarization and action potential firing. Under voltage-clamp conditions, EtOH (0. 1-40 mM) alone did not elicit a current. When coapplied with glycine, EtOH enhanced the glycine-induced current in 35% (180 of 474) of the neurons. The EtOH-induced enhancement of glycine current was independent of membrane potential (between -60 and +60 mV); the reversal potential was not changed. Concentration-response analysis showed that in the presence of EtOH (10 mM), the EC(50) for glycine decreased from 25 +/- 4 to 14 +/- 3 microM; the Hill coefficient increased from 1.5 +/- 0.2 to 1.9 +/- 0.3. Kinetic analysis of glycine currents indicated that EtOH decreased the time constant of activation and increased the time constant of deactivation of glycine-gated chloride channels. EtOH may accelerate glycine association with its receptor at the agonist binding site and increase the apparent agonist affinity. Our observations suggest that, at pharmacologically relevant concentrations, EtOH alters the function of glycine receptors and thus the excitability of neonatal VTA neurons. This action of EtOH may contribute to the neurobehavioral disturbances associated with fetal alcohol syndrome.

Survival of chronically-injured neurons can be prolonged by treatment with neurotrophic factors

Axonal regeneration by chronically-injured supraspinal neurons can be enhanced by neurotrophic factor treatment at the site of injury, although the number of regenerating neurons decreases as the interval between spinal cord injury and treatment increases. This study investigated whether this decline in regenerative response could be due to continued loss of neurons during the post-injury period. Adult rats received a cervical hemisection lesion and axotomized neurons were labeled by retrograde transport of True Blue from the lesion site. Animals were killed one, four or eight weeks after injury and surviving neurons (True Blue-labeled) were counted in the red nucleus and lateral vestibular nucleus. The neuron number in the lateral vestibular nucleus was stable for eight weeks after spinal cord injury, while survival in the red nucleus decreased by 25% between four and eight weeks. To test how neurons respond to a second injury with or without trophic factor treatment, at four, eight, 14 or 22 weeks after injury the lesion cavity was enlarged by 0.5 mm in a rostral direction. Gel foam saturated with ciliary neurotrophic factor, brain-derived neurotrophic factor or basic fibroblast growth factor was placed into the cavity. Animals were killed four weeks later. Re-injury of the spinal cord caused a significant decrease in neuron survival in both the red nucleus and lateral vestibular nucleus, the effects of which were lessened by treatment with ciliary neurotrophic factor or brain-derived neurotrophic factor for the red nucleus and with ciliary neurotrophic factor for the lateral vestibular nucleus, when re-injured at four or eight weeks. Basic fibroblast growth factor did not affect neuron survival at any time post-injury. Ciliary neurotrophic factor was not effective with longer delays (14 or 22 weeks) between the initial injury and re-injury. These results indicate a delayed pattern of secondary neuronal cell loss after spinal cord injury that is exaggerated by re-injury, but which can be ameliorated by treatment with neurotrophic factors.

Waglerin-1 inhibits GABA(A) current of neurons in the nucleus accumbens of neonatal rats

The effect of Waglerin-1, a 22-amino acid peptide purified from the venom of Wagler's pit viper on the whole cell current response (I(GABA)) to gamma-aminobutyric acid (GABA) was examined for neurons freshly isolated from the nucleus accumbens of 3- to 7-day-old rats. Waglerin-1 depressed I(GABA) induced by subsaturating concentrations of GABA; the IC(50) for I(GABA) induced by 10 microM GABA was 2.5 microM Waglerin-1. This concentration of Waglerin-1 shifted the GABA concentration-response curve to the right in a parallel manner, increasing the GABA EC(50) from 12+/-3 to 27+/-5 microM. The depressant effect of Waglerin-1 was greater at negative holding potentials. Zn(2+) also inhibited I(GABA) with an IC(50) of 0.3 microM. Phosphorylation state appeared to modulate GABA(A) receptor sensitivity to the inhibitory effect of Waglerin-1 since dialysis of neurons with N-[2-((p-bromocinnamyl)amino)ethyl]-5-isoquinolinesulfonamide HCl (H-89), an inhibitor of protein kinase A, prevented inhibition. The data are discussed in terms of developmental influences on the subunit composition of GABA(A) receptors in neurons of the nucleus accumbens.

Inhibitory effect of ondansetron on glycine response of dissociated rat hippocampal neurons

We examined the effect of ondansetron, an antagonist of type 3 serotonin receptors, on the whole cell response of freshly isolated hippocampal CA1 pyramidal neurons of neonatal and "mature" rats to glycine using the gramicidin perforated patch technique. Ondansetron depressed the current induced by subsaturating concentrations of glycine (IGly) in a concentration-dependent manner. The ondansetron concentration needed to depress IGly induced by 30 microM glycine to half amplitude was 25 microM. Ondansetron (54 microM) shifted the glycine concentration-response curve to the right in a parallel manner, increasing the EC50 for glycine from 40 +/- 3 microM to 70 +/- 5 microM. Ondansetron increased the time constant of activation of IGly without affecting the time constant of deactivation. When examined under current clamp conditions, glycine induced depolarization and hyperpolarization in neonatal and mature neurons, respectively; ondansetron also suppressed these responses to glycine. The data suggest that ondansetron competitively inhibits the glycine receptor.

Cocaine and lidocaine have additive inhibitory effects on the GABAA current of acutely dissociated hippocampal pyramidal neurons

Inhibition mediated by gamma-aminobutyric acid (GABA) is a major target for the central actions of cocaine and lidocaine, which can result in seizures, especially when these drugs are abused in combination. In the present study, we investigated how cocaine and lidocaine interact to depress GABA current (IGABA), recorded by the whole-cell technique in freshly isolated rat hippocampal neurons. Cocaine depressed IGABA in a concentration dependent manner, such that cocaine was more potent against lower than higher GABA concentrations: the cocaine IC50 was 0.13, 0.62 and 1.2 mM for GABA at 2, 10 and 100 microM, respectively. Cocaine depressed IGABA to the same extent in the absence and presence of 1 microM tetrodotoxin, indicating that cocaine inhibition of IGABA is distinct from its Na+ channel blocking action. Lidocaine reversibly depressed IGABA evoked by 10 microM GABA, with an IC50 of 9.8 mM. In the presence of 3 mM lidocaine, 0.3 mM cocaine depressed IGABA (10 microM GABA) to 30+/-7%. The significantly greater depression by the combined agents (p<0.05) indicates additive effects on the GABA receptor/channel complex, which are likely to contribute to the additive convulsant effects noted when these drugs are abused in combination.

Cocaine decreases the glycine-induced Cl- current of acutely dissociated rat hippocampal neurons

The effects of cocaine on glycine-induced Cl- current (I(GLY)) of single neurons, freshly isolated from the rat hippocampal CA1 area, were studied with conventional whole-cell recording under voltage-clamp conditions. Cocaine depressed I(GLY) in a concentration-dependent manner, with an IC50 of 0.78 mM. Preincubation with 1 mM cocaine alone had no effect on I(GLY), suggesting that resting glycine channels are insensitive to cocaine. The depression of I(GLY) by cocaine was independent of membrane voltage. Internal cell dialysis with 1 mM cocaine failed to modify I(GLY). Because the depression of I(GLY) was noncompetitive, cocaine may act on the glycine receptor-chloride ionophore complex at a site distinct from that to which glycine binds. The cocaine suppression of I(GLY) was unaffected by 1 microM tetrodotoxin and 1 microM strychnine. Blockers of protein kinase C (Chelerythrine), kinase A (N-[2-((p-bromocinnamyl)amino)ethyl]-5-isoquinolinesulfonamide HCl, (H-89)) and Ca-calmodulin-dependent kinase (1-[N,O-bis(5-isoquinoline-sulfonyl)-N-methyl-L-tyrosyl]-4-phenylpiperaz ine (KN-62)) were also ineffective, which suggests that these phosphorylating mechanisms do not modulate cocaine-induced suppressant action on I(GLY). This extracellular, strychnine-independent depression of I(GLY) may contribute to cocaine-induced seizures.

cAMP-dependent protein kinase modulation of glycine-activated chloride current in neurons freshly isolated from rat ventral tegmental area

Adenosine 3',5'cyclic monophosphate-(cAMP)-dependent protein kinase (PKA) modulation of glycine-activated Cl- currents (IGly) in single neurons freshly isolated from the rat ventral tegmental area (VTA) was studied using whole-cell patch-clamp technique. In the majority of cells tested with Mg-ATP in the internal solution, IGly induced by 3-10 microM glycine increased spontaneously (ran up). In the absence of internal ATP, IGly remained stable in six of seven cells. External perfusion of 8-Br-cAMP, a PKA activator, potentiated IGly only in cells showing run-up. 8-Br-cAMP potentiated IGly induced by low concentrations of glycine, but had no effect on the maximal current. When added to the pipette solution, H-89, a PKA inhibitor, blocked ATP and 8-Br-cAMP induced run-up of IGly. In contrast, dialysis with chelerythrine, a PKC inhibitor, did not alter the run-up of IGly. These results suggest that the PKA pathway modulates the activity of the glycine receptor/channel complex via enhancing the affinity of the receptor for glycine.

Glycine-activated chloride currents of neurons freshly isolated from the ventral tegmental area of rats

Properties of whole-cell glycine currents (IGly) of ventral tegmental area (VTA) neurons from 3- to 7-day old Sprague-Dawley rats were investigated with the patch-clamp technique. Ninety-three percent of the 126 neurons examined produced IGly in response to glycine. For 70% of these neurons, IGly did not decay in response to a threshold concentration of glycine (1-5 microM). At elevated glycine concentrations, IGly consistently decayed from a peak to a steady state (SS). IGly increased in amplitude sigmoidally as a function of the concentration of agonist with an EC50 of 32 microM. Strychnine (STR), when co-applied with glycine after a prepulse of STR, suppressed both the peak and SS IGly noncompetitively. In the absence of a prepulse, STR had a smaller effect on peak IGly while increasing its decay rate; the SS amplitude decreased. These STR effects were concentration dependent with an IC50 of 31 nM and 184 nM STR for the peak and SS IGly, with prepulse, respectively, and 732 nM and 193 nM for the peak and SS IGly, respectively, without prepulse. Picrotoxin (PTX) co-applied with glycine suppressed both the peak and the SS IGly with an IC50 of 25 microM. In contrast to STR, 1 min preincubation with PTX had no effect on IGly. Thus, PTX acts on the open channel. The inhibitory effects of both STR and PTX on IGly did not depend on the membrane potential.

[Post-traumatic reconnection of the cervical spinal cord with skeletal striated muscles. Study in adult rats and marmosets]

In an attempt at repairing the injured spinal cord of adult mammals (rat, dog and marmoset) and its damaged muscular connections, we are currently using: 1) peripheral nerve autografts (PNG), containing Schwann cells, to trigger and direct axonal regrowth from host and/or transplanted motoneurons towards denervated muscular targets; 2) foetal spinal cord transplants to replace lost neurons. In adult rats and marmosets, a PNG bridge was used to joint the injured cervical spinal cord to a denervated skeletal muscle (longissimus atlantis [rat] or biceps brachii [rat and marmoset]). The spinal lesion was obtained by the implantation procedure of the PNG. After a post-operative delay ranging from 2 to 22 months, the animals were checked electrophysiologically for functional muscular reconnection and processed for a morphological study including retrograde axonal tracing (HRP, Fast Blue, True Blue), histochemistry (AChE, ATPase), immunocytochemistry (ChAT) and EM. It was thus demonstrated that host motoneurons of the cervical enlargement could extend axons all the way through the PNG bridge as: a) in anaesthetized animals, contraction of the reconnected muscle could be obtained by electrical stimulation of the grafted nerve; b) the retrograde axonal tracing studies indicated that a great number of host cervical neurons extended axons into the PNG bridge up to the muscle; c) many of them were assumed to be motoneurons (double labelling with True Blue and an antibody against ChAT); and even alpha-motoneurons (type C axosomatic synapses in HRP labelled neurons seen in EM in the rat); d) numerous ectopic endplates were seen around the intramuscular tip of the PNG. In larger (cavitation) spinal lesions (rat), foetal motoneurons contained in E14 spinal cord transplants could similarly grow axons through PNG bridges up to the reconnected muscle. Taking all these data into account, it can be concluded that neural transplants are interesting tools for evaluating both the plasticity and the repair capacities of the mammalian spinal cord and of its muscular connections.

Ondansetron exhibits the properties of a local anesthetic

The purpose of this study was to determine whether ondansetron (OND) has local anesthetic effects. Using a patch-clamp technique, we showed that OND concentration dependently blocked Na channel currents in freshly isolated neurons of rat brains with a 50% inhibition concentration of 12 microM. The blockade started immediately when OND was applied to the cell body using a fast perfusion system, reached a plateau within 15 s, and recovered to the control level within 30 s after washout of the OND-containing solution. Because this is a known property of local anesthetics, we used the tail-flick technique to verify this effect in vivo in Sprague-Dawley rats (n = 46). OND was injected subcutaneously into the tail at the doses of 0.08, 0.16, and 0.2 mg. The tail-flick latency increased 2 min after OND injection, reaching the plateau within 5 min. This effect was dose-related, lasting from 10 to 25 min. These preliminary data indicate that OND, a selective 5-HT3 receptor antagonist, might serve as a prototype molecule for development of a novel series of local anesthetics.

IMPLICATIONS

Ondansetron is a drug used to prevent vomiting, especially in cancer patients after chemotherapy. We found that it also causes numbness when injected under the skin. This new action may contribute to its role in "calming the stomach." We studied the effect of ondansetron on the isolated brain cells of live rats.

Ondansetron modulates GABA(A) current of rat central nervous system neurons

We examined the effect of ondansetron, a 5-HT3 receptor antagonist, on the whole cell current response of freshly isolated hypothalamic and hippocampal neurons of rats to gamma-aminobutyric acid (GABA). The nystatin perforated patch technique was used to minimize run-down of the GABA current. While 1-150 microM ondansetron had no effect on membrane conductance, co-application with agonist reversibly depressed the maximal end GABA current. The concentration-response relation of GABA reveals a non-competitive mechanism. However, the inhibitory effect was more potent when ondansetron was co-applied with lower concentrations of GABA: i.e., the ondansetron concentration needed to depress the current induced by 5 microM GABA to half amplitude was 7 microM compared to 28 microM for the current induced by 10 microM GABA. Analysis of the current-voltage relationship with and without ondansetron indicated that the effect of ondansetron is not voltage dependent. Current-voltage relations also showed that the effect of ondansetron was not due to activation of a GABA-independent current because the reversal potentials were the same with and without ondansetron. The present data suggest that ondansetron's suppression of GABA-activated current may be the molecular basis of ondansetron-induced seizures observed in vivo.

Cocaine depresses GABAA current of hippocampal neurons

Although blockade of dopamine re-uptake and the resulting elevation of excitatory agonists is commonly thought the primary mechanism of cocaine-induced seizures, it is possible that other neurotransmitters such as gamma-aminobutyric acid (GABA) are involved. To examine this possibility, the effects of cocaine on the whole cell GABA current (IGABA) of freshly isolated rat hippocampal neurons were investigated with the patch-clamp technique. Preincubation or acute application of cocaine reversibly suppressed IGABA. The IC50 was 127 microM when cocaine was applied before the application of GABA. The concentration-response relations of cocaine in various GABA concentrations revealed that cocaine inhibited IGABA non-competitively. This effect of cocaine appeared to be independent of voltage. The present study suggests that the GABA receptor/channel complex is also a target for cocaine's action. The suppression of IGABA may contribute to cocaine-induced seizures.

Waglerin-1 modulates gamma-aminobutyric acid activated current of murine hypothalamic neurons

We examined the effect of Waglerin-1, a peptide of 22 amino acid residues purified from the venom of Wagler's pit viper (Trimeresurus wagleri), on the whole cell current response (I(GABA)) of freshly isolated murine hypothalamic neurons to gamma-aminobutyric acid (GABA). Although the application of 32 microM Waglerin-1 alone had no effect on membrane conductance, coapplication with GABA increased I(GABA) for 78 and suppressed I(GABA) for 44 of the 141 neurons examined. The potentiating effect of Waglerin-1 was associated with a leftward shift of the concentration-response relation of GABA without increasing peak I(GABA). This potentiating effect of Waglerin-1 on I(GABA) mimics diazepam. Furthermore, the benzodiazepine antagonist flumazenil antagonized Waglerin-1 potentiation of I(GABA), These observations suggest that Waglerin-1 acts on the benzodiazepine site of one type of GABA(A) receptor/channel complex to increase its affinity for agonist. In contrast, the depressant effect of Waglerin-1 was associated with a rightward shift of the concentration-response relation of GABA without depressing the maximal I(GABA); this suggests a competitive inhibition of a second class of GABAR. The ability of Waglerin-1 to suppress I(GABA) showed a positive correlation with a similar action of Zn++. As with Zn++, the depressant effect of Waglerin-1 on I(GABA) was more pronounced at negative holding potentials. These observations are discussed in terms of variation in the subunit composition of GABA receptors that murine central nervous system neurons express.