[Research progress in the promotion of peri-implant soft tissue integration of dental titanium implant based on immune microenvironment regulation]

A good integration of dental implants and the surrounding soft tissue is essential to ensure the long-term effect of implant. In this review, we summarized the research progress of peri-implant soft tissue integration of dental titanium implants, with emphasis on the modification of the gingival interface of implants based on immune microenvironment regulation. This method influences the immune response around the implant by promoting the surface properties of implants, so as to enhance the peri-implant soft tissue integration. The purpose of this review is to provide reference for the related research and clinical application in the field of dental implantation.

[Clinical observation of the relationship between the newborn hearing screening and ABO blood groups]

Objective:To analyze the relationship between ABO blood groups and otoacoustic emissions in full-term newborns, including the occurrence of SOAE and the amplitudes of DPOAE. Method:A total of eighty normal hearing female neonates were included in the study, with equal number of participants in each of the ABO blood group. Measurements of SOAE and DPOAE were collected from both ears of all participants. Result:The blood group O subjects showed significantly fewer SOAE occurrences and lower DPOAE amplitudes at 793 Hz, 1 257 Hz and 1 587 Hz than subjects with other three blood groups both in the left and right ears. Conclusion:The full-term neonates with blood group O have lower SOAE occurrence than other three blood group individual. The blood group O individuals have the lowest amplitude at 793 Hz, 1 257 Hz and 1 587 Hz of both ears.

Association between RNF41 gene c.-206 T > A genetic polymorphism and risk of congenital heart diseases in the Chinese Mongolian population

This study aimed to explore the association between ring finger protein 41 (RNF41) c.-206 T > A variant and susceptibility to congenital heart disease (CHD) in the Chinese Mongolian population. The association between RNF41 gene c.-206 T > A polymorphism and CHD was examined in two independent case-control studies consisting of 219 CHD patients and 208 healthy controls. Genotype was determined by direct sequencing of PCR products. We found that the genotype frequencies of RNF41 c.-206 T > A differ significantly between the two groups (P < 0.05). The TT and TA genotypes in the CHD group were 80.67 and 19.33%, respectively. On the other hand, the frequencies of TT and TA in the control group were 94.44 and 5.56%, respectively. Furthermore, the allelic frequencies of CHD patients (T, 90.34%; A, 9.66%) were significantly different as compared with those of non-CHD controls (T, 97.22%; A, 2.78%; χ2 = 4.031, P = 0.041). Our study demonstrates that the RNF41 c.-206 T > A polymorphism may be a risk factor for congenital heart disease in the Chinese Mongolian population.

Plasminogen kringle 5 induces endothelial cell apoptosis by triggering a voltage-dependent anion channel 1 (VDAC1) positive feedback loop

Human plasminogen kringle 5 (K5) is known to display its potent anti-angiogenesis effect through inducing endothelial cell (EC) apoptosis, and the voltage-dependent anion channel 1 (VDAC1) has been identified as a receptor of K5. However, the exact role and underlying mechanisms of VDAC1 in K5-induced EC apoptosis remain elusive. In the current study, we showed that K5 increased the protein level of VDAC1, which initiated the mitochondrial apoptosis pathway of ECs. Our findings also showed that K5 inhibited the ubiquitin-dependent degradation of VDAC1 by promoting the phosphorylation of VDAC1, possibly at Ser-12 and Thr-107. The phosphorylated VDAC1 was attenuated by the AKT agonist, glycogen synthase kinase (GSK) 3β inhibitor, and siRNA, suggesting that K5 increased VDAC1 phosphorylation via the AKT-GSK3β pathway. Furthermore, K5 promoted cell surface translocation of VDAC1, and binding between K5 and VDAC1 was observed on the plasma membrane. HKI protein blocked the impact of K5 on the AKT-GSK3β pathway by competitively inhibiting the interaction of K5 and cell surface VDAC1. Moreover, K5-induced EC apoptosis was suppressed by VDAC1 antibody. These data show for the first time that K5-induced EC apoptosis is mediated by the positive feedback loop of "VDAC1-AKT-GSK3β-VDAC1," which may provide new perspectives on the mechanisms of K5-induced apoptosis.

Pigment epithelial-derived factor (PEDF)-triggered lung cancer cell apoptosis relies on p53 protein-driven Fas ligand (Fas-L) up-regulation and Fas protein cell surface translocation

Pigment epithelium-derived factor (PEDF), a potent antiangiogenesis agent, has recently attracted attention for targeting tumor cells in several types of tumors. However, less is known about the apoptosis-inducing effect of PEDF on human lung cancer cells and the underlying molecular events. Here we report that PEDF has a growth-suppressive and proapoptotic effect on lung cancer xenografts. Accordingly, in vitro, PEDF apparently induced apoptosis in A549 and Calu-3 cells, predominantly via the Fas-L/Fas death signaling pathway. Interestingly, A549 and Calu-3 cells are insensitive to the Fas-L/Fas apoptosis pathway because of the low level of cell surface Fas. Our results revealed that, in addition to the enhancement of Fas-L expression, PEDF increased the sensitivity of A549 and Calu-3 cells to Fas-L-mediated apoptosis by triggering the translocation of Fas protein to the plasma membrane in a p53- and FAP-1-dependent manner. Similarly, the up-regulation of Fas-L by PEDF was also mediated by p53. Furthermore, peroxisome proliferator-activated receptor γ was determined to be the upstream regulator of p53. Together, these findings uncover a novel mechanism of tumor cell apoptosis induced by PEDF and provide a potential therapeutic strategy for tumors that are insensitive to Fas-L/Fas-dependent apoptosis because of a low level of cell surface Fas.

Dual inhibition of plasminogen kringle 5 on angiogenesis and chemotaxis suppresses tumor metastasis by targeting HIF-1α pathway

We had demonstrated that plasminogen kringle 5 (K5), a potent angiogenic inhibitor, inhibited retinal neovascularization and hepatocellular carcinoma growth by anti-angiogenesis. The current study investigated the effects and the underlying mechanisms of K5 on both tumor growth and spontaneous pulmonary metastasis in Lewis lung carcinoma (LLC) implanted mouse model. Similarly, K5 could decrease expression of VEGF in LLC cells and grafted tissues and suppress tumor angiogenesis and growth. K5 had no direct effect on proliferation and apoptosis of LLC. However, K5 could significantly inhibit SDF-1α-induced chemotaxis movement of LLC cells and resulted in a great reduction of surface metastatic nodules and micrometastases in the lungs of LLC tumor-bearing mice. K5 also decreased expression of chemokine (C-X-C motif) receptor 4 (CXCR4) in LLC cells and grafted tissues. Furthermore, K5 down-regulated SDF-1α expression in metastatic lung tissues of LLC-bearing mice. Therefore, K5 may suppress tumor pulmonary metastasis through inhibiting SDF-1α-CXCR4 chemotaxis movement and down-regulation of VEGF. Moreover, the role of hypoxia inducible factor-1α (HIF-1α), a crucial transcriptional factor for both VEGF and CXCR4 expression, was evaluated. The siRNA of HIF-1α attenuated expression of VEGF and CXCR4 and inhibited LLC migration. K5 decreased HIF-1α protein level and impaired nuclear HIF-1α accumulation. These results showed for the first time that K5 inhibits LLC growth and metastasis via the dual effects of anti-angiogenesis and suppression of tumor cell motility by targeting the pivotal molecule, HIF-1α.

Construction of a vector carrying a small hairpin RNA targeting the HIF-1α gene and its expression in gastric cancer cells

AIM: To construct a plasmid carrying a small hairpin RNA (shRNA) targeting the HIF-1α gene and to observe its expression in gastric cancer SGC-7901 cells.

METHODS: SHIF-1α-specific shRNA sequence was designed, synthesized and cloned into the expression vector pSilencer 1.0-U6. The recombinants were identified by double digestion with EcoRⅠ+ ApaⅠand DNA sequencing, and then transfected into SGC-7901 cells under hypoxia. Forty-eight hours after transfection, HIF-1α expression was detected by Western blotting.

RESULTS: Restriction enzyme digestion and DNA sequencing confirmed that the shRNA was correctly inserted into the plasmid pSilencer 1.0-U6. The recombinant plasmid carrying the shRNA targeting HIF-1α was successfully transfected into SGC-7901 cells. Western blot analysis suggested that HIF-1α expression was knocked down in transfected cells compared to control cells.

CONCLUSION: A plasmid carrying a shRNA targeting HIF-1α has been constructed successfully, and SGC-7901 cells stably transfected with this recombinant vector have been obtained. These will offer favorable tools for studying HIF-1α-targeted gene therapy.

Nerve growth factor-beta expression is associated with lymph node metastasis and nerve infiltration in human hilar cholangiocarcinoma

BACKGROUND

Angiogenesis and lymphangiogenesis are important processes in the progression of malignant tumors. Previous studies have shown that nerve growth factor-beta (NGF-beta) can promote the initiation and progression of many tumors. In addition, vascular endothelial growth factor-C (VEGF-C) has become recognized as the most important lymphangiogenic factor. In the present study, the expression of NGF-beta in human hilar cholangiocarcinoma and its relationship with lymphangiogenesis, lymph node metastasis, nerve infiltration, and VEGF-C expression was investigated.

METHODS

Nerve growth factor-beta and VEGF-C expression were investigated by immunohistochemistry in samples from 28 cases of hilar cholangiocarcinoma. The lymphatic vessel density (LVD) in the tumor tissue that indicated lymphangiogenesis were calculated by immunostaining with the lymphendothelial-specific antibody D2-40. The relationship between NGF-beta expression and VEGF-C expression, lymphangiogenesis, lymph node metastasis, and nerve infiltration was evaluated.

RESULTS

The overexpression of NGF-beta and VEGF-C occurred in 57.1% (16/28) and 46.4% (13/28) of tumor samples, respectively. Nerve growth factor-beta overexpression was highly correlated with VEGF-C overexpression (P = 0.005), LVD (P < 0.001), lymph node metastasis (P = 0.021), nerve infiltration (P = 0.019), and tumor stage (P = 0.040). Furthermore, VEGF-C overexpression was highly correlated with LVD (P < 0.001) and lymph node metastasis (P < 0.001). However, there was no statistic significance in the relation between NGF-beta expression and sex (P = 0.185), age (P = 0.387), maximal tumor size (P = 0.736), Bismuth classification (P = 0.627) as well as histological grade (P = 0.203).

CONCLUSIONS

Nerve growth factor-beta might promote lymph node metastasis and nerve infiltration in human hilar cholangiocarcinoma.

Novel method for expression and purification of human pigment epithelium-derived factor with biological activities in Escherichia coli

We developed a novel method for the expression and purification of recombinant human PEDF in Escherchia coli, and proved it to be simple, convenient, and cheap to obtain this protein with biological activity intact. Human PEDF gene, amplified by PCR from human retinal cNDA library, was cloned into the prokaryotic expression vector pET-22b(+). The recombinant pET-22b(+)/PEDF was expressed in E. coli strain BL21(DE3). The recombinant protein showed a molecular weight of about 50 kDa and was mainly in the form of inclusion bodies according to SDS-PAGE and Western blot analysis. The insoluble rPEDF was solublized from inclusion bodies by denaturation using 6 M urea, purified by His-tag affinity chromatography, and renatured to natural structure by dialysis in the presence of DTT. The rPEDF could cell-type-specifically inhibit HRCEC proliferation in a dose-dependent manner and induce HRCEC apoptosis.

[Potentiation by Rabdosia rubescens on chemotherapy of advanced esophageal carcinoma]

One hundred and fifteen patients with inoperable esophageal carcinoma were treated by either chemotherapy alone or chemotherapy plus Rabdosia rubescens. In group A, out of 31 patients treated with pingyangmycin (P) and nitrocaphane (N), 10 (32.3%) responded to the treatment. Among them, 2 showed partial response (greater than 50% tumor regression) and 8 minimal response (greater than 50% tumor regression). In group B, out of 84 patients treated with PN plus Rabdosia rubescens, 59 (70.2%) responded. Of them, 10 showed complete response (100% tumor regression), 16 partial response and 33 minimal response. the one-year survival rates of group A and B were 13.6% and 41.3%. Statistical significance was present in these two groups both in the response rate and one-year survival rate. As regards the drug toxicity, there was no significant difference between these two groups. Alopecia, anorexia, nausea and hyperpyrexia occurred in more than 30% of patients. Mild leukopenia and thrombocytopenia and interstitial pneumonia were noted in some patients, and two patients died of toxicity in the lungs.