Role of indoleamine 2,3-dioxygenase in an inflammatory model of murine gingiva

BACKGROUND AND OBJECTIVE

Indoleamine 2,3-dioxygenase (IDO) is one of the major pathways for metabolism of tryptophan in a variety of cells, including immune cells. Increasing evidence indicates that IDO is a critical player in establishing the balance between immunity and tolerance and ultimately in the maintenance of homeostasis. By inducing inflammation in gingival tissue, we tested the hypothesis that IDO is a pivotal player in regulating the immune and inflammatory responses of gingiva.

MATERIAL AND METHODS

We utilized the IDO knockout mouse model in conjunction with lipopolysaccharide (LPS)-induced inflammation. Accordingly, wild-type and IDO knockout mice were injected with LPS or vehicle in the anterior mandibular gingiva, twice over a 2-wk period, which was followed by procurement of gingival tissue for histopathology and preparation of tissue for flow cytometry-based studies.

RESULTS

Clinical and histological examinations revealed a marked adverse impact of IDO deficiency on gingival inflammation. These observations were consistent with a more marked increase in the number of cells positive for the proinflammatory cytokine interleukin (IL)-17, but no significant change in the number of cells positive for the anti-inflammatory cytokine IL-10, in LPS-treated IDO knockout mice. Consistent with the more marked proinflammatory impact of IDO deficiency, the percentage of regulatory T cells was much reduced in gingival tissue of LPS-treated IDO knockout mice than in gingival tissue of wild-type mice. These proinflammatory changes were accompanied with a prominent increase in apoptotic and necrotic cell death in gingival tissue of IDO knockout mice compared with wild-type mice.

CONCLUSION

Collectively, our findings support a major role for IDO in the development of gingival inflammation, as an example of an inflammatory condition, and lay the foundation for subsequent studies to explore it as a novel immunotherapy target.

LINC01225 promotes occurrence and metastasis of hepatocellular carcinoma in an epidermal growth factor receptor-dependent pathway

The long noncoding RNAs (lncRNAs) have long been clarified to participate in hepatocellular carcinoma (HCC) as a biomarker. We carried out the present study in order to identify HCC-related lncRNAs and elucidate the functional roles in the development and progression of HCC. Our previous study has provided that LINC01225 may be an HCC-related gene. Here, we verified that LINC01225 was upregulated in HCC. Knockdown of LINC01225 resulted in inhibited cell proliferation and invasion with activated apoptosis and cell cycle arrest in vitro. Overexpression of LINC01225 in LINC01225 knockdown cells presented that attenuated cell proliferation and invasion were restored and enhanced. Subcutaneous and tail vein/intraperitoneal injection xenotransplantation model in vivo validated reduced tumor progression and metastasis. Investigation of mechanism found that LINC01225 could bind to epidermal growth factor receptor (EGFR) and increase the protein level of EGFR, and subsequently fine tune the EGFR/Ras/Raf-1/MEK/MAPK signaling pathway. Analysis with clinicopathological information suggested a high expression of LINC01225 is positively associated with poor prognosis. We also proved that LINC01225 was stably expressed in serum and can act as a novel biomarker in predicting the diagnosis of HCC. As a conclusion, LINC01225 plays a crucial role in HCC and can act as a biomarker for the diagnosis and prognosis of HCC.

Possible relevance of tumor-related genes mutation to malignant transformation of endometriosis

OBJECTIVE

Despite studies have suggested that endometriosis has malignant potential, the molecular mechanism underlying the malignant transformation of endometriosis is poorly understood so far. Endometriosis-associated ovarian cancer (EAOC) or ovarian cancer arising from endometriosis (OCEM) may provide an ideal model for genetic studies. To investigate the genetic alterations during transformation of ovarian endometriosis into cancer, the authors analysed mutations of tumour-related genes (PTEN and p53) in EAOC cases (n=23, group 1), including 19 cases which were detected co-existence of endometriosis and cancer and four cases which fulfilled the histological criteria in malignant transformation of endometriosis (OCEMs), and in atypical hyperplasia ovarian endometriosis (aEMs) (n = 10, group 2), as well as in solitary ovarian endometriosis (EMs) (n = 20, group 3), simultaneously, to study the correlation of the two genes in the development and progression of the ovarian endometriosis malignancy.

MATERIALS AND METHODS

Each paraffin block was sliced into serial ten-µm-thick sections. Extracted DNA was amplified by nested PCR. Mutations of PTEN and p53 were examined by bidirectional DNA sequencing.

RESULTS

It was acknowledged by experiments that the PTEN and p53 mutation frequency in EAOCs were significantly higher than that in aEMs and EMs. There was significant difference to compare EAOCs with EMs (p < 0.01, p < 0.05), and converse to compare with aEMs (p > 0.05), respectively. No definite involvement between the frequency of PTEN and p53 mutations in EAOCs and age difference, histological type, clinical stage, pathological grade, and whether accompanied by metastasis (p > 0.05); however, a decreasing trend of PTEN mutation with the increased age, decreased clinical stage and pathological grade, and when accompanied by metastasis was detected. Adversely, an increasing trend of p53 mutation was represented. In EAOCs group, the authors detected eight PTEN and four p53 mutation events, respectively. Moreover, one case occurred PTEN and p53 mutation simultaneously. With 23 EAOCs, two cases which fulfilled the histological criteria in malignant transformation of endometriosis, which may be a specific entity distinct from non-endometriosis-associated ovarian cancer, the authors named them the OCEMs, occurred PTEN or p53 mutation, respectively.

CONCLUSION

The present study suggested that the mutation and functional incapacitation of certain tumor-related genes may be involved in malignant transformation of endometriosis. PTEN mutation is the pristine event, but p53 mutation is the late.

Precision Measurement of the Helium Flux in Primary Cosmic Rays of Rigidities 1.9 GV to 3 TV with the Alpha Magnetic Spectrometer on the International Space Station

Knowledge of the precise rigidity dependence of the helium flux is important in understanding the origin, acceleration, and propagation of cosmic rays. A precise measurement of the helium flux in primary cosmic rays with rigidity (momentum/charge) from 1.9 GV to 3 TV based on 50 million events is presented and compared to the proton flux. The detailed variation with rigidity of the helium flux spectral index is presented for the first time. The spectral index progressively hardens at rigidities larger than 100 GV. The rigidity dependence of the helium flux spectral index is similar to that of the proton spectral index though the magnitudes are different. Remarkably, the spectral index of the proton to helium flux ratio increases with rigidity up to 45 GV and then becomes constant; the flux ratio above 45 GV is well described by a single power law.

Precision Measurement of the Proton Flux in Primary Cosmic Rays from Rigidity 1 GV to 1.8 TV with the Alpha Magnetic Spectrometer on the International Space Station

A precise measurement of the proton flux in primary cosmic rays with rigidity (momentum/charge) from 1 GV to 1.8 TV is presented based on 300 million events. Knowledge of the rigidity dependence of the proton flux is important in understanding the origin, acceleration, and propagation of cosmic rays. We present the detailed variation with rigidity of the flux spectral index for the first time. The spectral index progressively hardens at high rigidities.

Local administration of AAV-DJ pseudoserotype expressing COX2 provided early onset of transgene expression and promoted bone fracture healing in mice

We have previously obtained compelling proof-of-principle evidence for COX2 gene therapy for fracture repair using integrating retroviral vectors. For this therapy to be suitable for patient uses, a suitable vector with high safety profile must be used. Accordingly, this study sought to evaluate the feasibility of AAV as the vector for this COX2 gene therapy, because AAV raises less safety issues than the retroviral vectors used previously. However, an appropriate AAV serotype is required to provide early increase in and adequate level of COX2 expression that is needed for fracture repair. Herein, we reported that AAV-DJ, an artificial AAV pseudoserotype, is highly effective in delivering COX2 gene to fracture sites in a mouse femoral fracture model. Compared with AAV-2, the use of AAV-DJ led to ~5-fold increase in infectivity in mesenchymal stem cells (MSCs) and provided an earlier and significantly higher level of transgene expression at the fracture site. Injection of this vector at a dose of 7.5 × 10(11) genomic copies led to high COX2 level at the fracture site on day 3 after injections and significantly promoted fracture union at 21 days, as analyzed by radiography and μ-CT. The therapeutic effect appears to involve enhanced osteoblastic differentiation of MSCs and remodeling of callus tissues to laminar bone. This interpretation is supported by the enhanced expression of several key genes participating in the fracture repair process. In conclusion, AAV-DJ is a promising serotype for the AAV-based COX2 gene therapy of fracture repair in humans.

The pleiotropic roles of sphingolipid signaling in autophagy

The autophagic process involves encompassing damaged proteins and organelles within double- or multi-membraned structures and delivering these molecules to the lytic compartments of vacuoles. Sphingolipids (SLs), which are ubiquitous membrane lipids in eukaryotes, participate in the generation of various membrane structures, including rafts, caveolae, and cytosolic vesicles. SLs are a complex family of molecules that have a growing number of members, including ceramide, sphingosine-1-phosphate, and dihydroceramide, which have been associated with the essential cellular process of autophagy. This review highlights recent studies focusing on the regulation and function of SL-associated autophagy and its role in cell fate, diseases, and therapeutic interventions.

Spinal toll-like receptor 4-mediated signalling pathway contributes to visceral hypersensitivity induced by neonatal colonic irritation in rats

BACKGROUND

Although visceral hypersensitivity is a major pathophysiological feature of irritable bowel syndrome (IBS), its underlying mechanisms remain elusive. Toll-like receptor 4 (TLR4) is a critical pattern recognition molecule of the innate immune system. In this study, we investigated whether the TLR4/myeloid differentiation factor 88 (MyD88)/nuclear factor-kappa B (NF-κB) signalling pathway in the spinal cord contributed to the visceral hypersensitivity induced by neonatal colonic irritation (CI) in rats.

METHODS

The Sprague-Dawley rat model of IBS was induced by colon irritation on post-natal day (PND) 8, PND10 and PND12. Experiments were conducted in adult rats. TLR4 mRNA and protein, and its downstream signalling molecules, MyD88, inhibitory nuclear factor-kappa B (IκB) and NF-κB protein expressions in L2-S4 spinal segments were detected by quantitative real-time reverse transcription-polymerase chain reaction as well as Western blotting. TLR4 co-localization was determined by immunohistochemistry. Levels of tumour necrosis factor-alpha (TNF-α) and interleukin 1β (IL-1β) were measured with enzyme-linked immunosorbent assay.

RESULTS

We found that neonatal CI treatment induced long-lasting visceral hypersensitivity without identifiable structural abnormalities in descending colons of adult rats. Neonatal CI treatment evoked a significant up-regulation of the expressions of TLR4 in glia, MyD88, p-IκB-α and NF-κB in adult rats. Neonatal CI treatment also increased the levels of its downstream inflammatory agents TNF-α and IL-1β in the L2-S4 regions of the spinal cord of adult rats.

CONCLUSIONS

These results suggest that neonatal CI stimulates the production of IL-1β and TNF-α through the TLR4/MyD88/NF-κB signalling pathway in the spinal cord, which contributed to visceral hypersensitivity induced by neonatal CI in rats.

Lack of association between EPHX1 polymorphism and esophageal cancer risk: evidence from meta-analysis

The microsomal epoxide hydrolase 1 (EPHX1) Tyr113His and His139Arg polymorphisms have been reported to be associated with esophageal cancer (EC) risk, yet the results of these previous results have been inconsistent or controversial. The objective of this study was to explore whether the EPHX1 Tyr113His and His139Arg polymorphisms confer risk to EC. The relevant studies were identified through a search of PubMed, Excerpta Medica Database (Embase), Elsevier Science Direct, and Chinese Biomedical Literature Database until May 2013. The association between the EPHX1 Tyr113His and His139Arg polymorphisms and EC risk was pooled by odds ratios (ORs) together with their 95% confidence intervals (95%CIs). A total of eight case-control studies with 1163 EC patients and 1868 controls (seven studies for both Tyr113His and His139Arg polymorphisms, one study only for Tyr113His polymorphism) were eventually identified. We found no association between EPHX1 Tyr113His and His139Arg polymorphisms and EC risk in overall population (For Tyr113His: His vs. Tyr: OR = 1.05, 95%CI = 0.95-1.15, P = 0.379; His/His vs. Tyr/Tyr: OR = 1.04, 95%CI = 0.88-1.22, P = 0.208; His/Tyr vs. Tyr/Tyr: OR = 0.96, 95%CI = 0.80-1.15, P = 0.577; His/His vs. His/Tyr + Tyr/Tyr: OR = 1.10, 95%CI = 0.96-1.26, P = 0.164; His/His + His/Tyr vs. Tyr/Tyr: OR = 1.01, 95%CI = 0.90-1.12, P = 0.543. For His139Arg: Arg vs. His: OR = 1.04, 95%CI = 0.94-1.14, P = 0.465; Arg/Arg vs. His/His: OR = 1.06, 95%CI = 0.91-1.24, P = 0.470; Arg/His vs. His/His: OR = 1.03, 95%CI = 0.91-1.16, P = 0.673; Arg/Arg vs. Arg/His + His/His: OR = 1.04, 95%CI = 0.85-1.27, P = 0.708; Arg/Arg + Arg/His vs. His/His: OR = 1.02, 95%CI = 0.93-1.13, P = 0.617). In subgroup analysis based on ethnicity, significant association has been found in neither EPHX1 Tyr113His nor His139Arg polymorphism. The current meta-analysis suggests no evidence of association between the EPHX1 polymorphism and EC risk.

Duration of viraemia in Chinese acute sporadic hepatitis E

Acute sporadic hepatitis E (ASHE) cases induced by hepatitis E virus genotype 4 (HEV-4) are increasing in China. Our study aimed to estimate the duration of HEV-4 viraemia in Chinese ASHE. A total of 619 serum specimens from 499 ASHE patients were examined for the presence of HEV RNA. The association between viraemia detection and serum sampling time was compared between subtypes. The cumulative probability of HEV viraemia detection was determined using Kaplan-Meier survival analysis, and the viraemia duration was estimated. A total of 42.7 % of serum specimens were positive for HEV RNA and all the isolated strains were identified as genotype 4 and subsequently assigned to five subtypes. Among the patients infected with subtypes 4d and 4i, the time interval from the initiation of clinical symptoms to serum specimen sampling was shorter than that among the patients with subtypes 4a, 4b and 4h. Kaplan-Meier analysis was conducted with 101 sequential specimens as well as with both 101 sequential specimens and 236 single negative specimens. The cumulative probability of HEV-4 viraemia detection was estimated to decline quickly to approximately 10 % within 32 days after the initiation of clinical symptoms and then to decline very slowly to 5 % by the 41st day and to zero by the 131st day. The majority of ASHE cases maintain detectable HEV-4 viraemia within one month after onset, whereas a small portion of cases maintain long-term viraemia and may act as a reservoir for further transmission.

The results of surgery for colorectal hepatic metastases following expansion of the indications in 2005

AIM

Safety and survival were investigated in patients treated according to expanded surgical indications for colorectal hepatic metastases.

METHOD

A retrospective analysis of all consecutive patients who underwent resection of colorectal hepatic metastases at Zhongshan Hospital from 2000 to 2010 was conducted. The patients were divided into two groups based on a change in the surgical indications introduced in 2005. Patients in Group I underwent hepatic surgery between 2000 and 2004 and those in Group II between 2005 and 2010. The clinicopathological data and survival rates of both groups were analysed.

RESULTS

There were 530 patients who underwent hepatic surgery between 2000 and 2010. After the expansion of surgical indications, the rate of surgical resection rose from 25.1 to 35.1% (P < 0.05). There was no significant difference in perioperative mortality (2.2% vs 0.9%) or morbidity (20.9% vs 29.8%). Recurrence occurred in 27.5% and 36.7% in Groups I and II, respectively, and 5-year overall survival was 43% and 49%, respectively (not significant).

CONCLUSION

Expanding the indications for surgical resection of hepatic metastases increased the resection rate but had no significant effect on survival.

Variations in circulating sex steroid levels in metastatic prostate cancer patients with combined androgen blockade: observation and implication

Testosterone is the major precursor of estradiol (E2) in men. We hypothesized that, in metastatic prostate cancer, androgen deprivation therapy suppression of serum androgen to the castration level may also disrupt serum E2 level, and variation in serum E2 level might play a role in the development of castration-resistant prostate cancer. Our investigation was designed to observe the variation in circulating oestrogen and androgen levels in metastatic prostate cancer patients after combined androgen blockade, and to explore the possible clinical significance. We recruited 105 consecutive metastatic prostate cancer patients who were treated with combined androgen blockade from June to August 2011, and divided them into three groups according to different hormone-sensitivity status, including 58 hormone-sensitive prostate cancers, 27 after failure of first-line hormone therapy (androgen-independent prostate cancer) and 20 castration-resistant prostate cancers. Another 36 consecutive patients with treatment-naive metastatic prostate cancer during the same period were used as controls. Serum testosterone, E2 and E2/testosterone (E2/T) ratio were analysed and compared between the groups. After combined androgen blockade, testosterone was suppressed to a low level, regardless of different hormone sensitivity (p > 0.05). Mean serum testosterone was 4.07, 0.15, 0.11 and 0.09 ng/mL in treatment-naive, hormone-sensitive, androgen-independent and castration-resistant prostate cancer respectively. For each group, mean E2 was 33.06, 9.23, 9.13 and 15.05 pg/mL respectively. Mean E2/T was 9.58, 269.29, 292.06 and 996.67 respectively. Recovery of E2 and increased E2/T ratio were more significantly associated with combined androgen blockade failure, especially in castration-resistant prostate cancer (p < 0.001). This study indicated that metabolism of oestrogen might change during combined androgen blockade in metastatic prostate cancer patients, and oestrogen-related pathways might play a role in the development of castration-resistant prostate cancer.

Distant lymph nodes serve as pools of Th1 cells induced by neonatal BCG vaccination for the prevention of asthma in mice

BACKGROUND

Neonatal Bacillus Calmette-Guérin (BCG) vaccination induces vigorous T-helper type 1 (Th1) responses and inhibits allergy-related airway dysfunction, but the exact mechanisms remain unclear. The objective of this study was to address where the Th1 cells induced by neonatal BCG vaccination are generated and stored, and how they are recruited into the inflamed airway for the prevention of allergen-induced airway inflammation.

METHODS

We vaccinated neonatal C57BL/6 mice with BCG in a mouse model of asthma and analyzed the expression and function of Th1 cells in vivo and in vitro.

RESULTS

BCG vaccination-induced Th1 cells in the local inguinal lymph nodes (ILN) migrated into the lungs upon inhaled ovalbumin (OVA) challenge in OVA-sensitized mice. These CD4(+) T cells in the ILN exhibited potentials of activation, proliferation and cytokine secretion and expressed high levels of CXCR3. Adoptive transfer of CD4(+) T cells from BCG-treated ILN significantly decreased allergic airway responses. In addition, the protective effect of BCG vaccination against allergic airway inflammation was lost upon the excision of the ILN.

CONCLUSIONS

These data demonstrate that ILN serves as a 'weapon' pool of Th1 cells following BCG vaccination, and these cells are ready for the migration into the inflamed lungs upon the allergen challenge, thereby inhibiting allergen-induced airway disorder.

Prospective feasibility study on the use of multiband mucosectomy for endoscopic resection of early squamous neoplasia in the esophagus

BACKGROUND AND STUDY AIMS

Endoscopic resection for esophageal squamous high-grade intraepithelial neoplasia (HGIN) or intramucosal cancer (esophageal squamous cell carcinoma [ESCC]) with the endoscopic resection cap technique is technically difficult, and requires submucosal lifting and multiple snares for piecemeal resections. Multiband mucosectomy (MBM) is an easy-to-use endoscopic resection technique and may be the modality of choice in China, where ESCC is extremely prevalent. The aim of the current study was to prospectively evaluate MBM for piecemeal endoscopic resection of squamous neoplasia of the esophagus.

METHODS

Patients with HGIN/ESCC and no signs of submucosal invasion or metastatic disease were included in the study. Lesions were delineated using electrocoagulation and resected using the MBM technique. Endpoints were procedure time, endoscopic radicality, complications, histology of the endoscopic resection specimens, and absence of HGIN/ESCC at the endoscopic resection scar during follow-up.

RESULTS

A total of 41 patients (26 male; mean age 61 years) underwent MBM; all lesions were visible with white light endoscopy (median length 5 cm, interquartile range [IQR] 4 - 6 cm; median circumferential extent 42 %, IQR 25 - 50 %). Median procedure time was 12 minutes (IQR 8 - 24 minutes). Median number of resections was 5 (IQR 3 - 6). Endoscopic complete resection was achieved in all lesions. There was one perforation, which was treated by application of clips. No other complications were observed. The worst histology was ESCC (n = 19), HGIN (n = 17), middle grade intraepithelial neoplasia (n = 4), and normal squamous epithelium (n = 1). Endoscopic follow-up at 3 months showed HGIN at the endoscopic resection scar in two patients, which was effectively treated endoscopically, and showed normal squamous epithelium in all patients at final follow-up (median 15 months, IQR 12 - 24 months).

CONCLUSION

This first prospective study on MBM for piecemeal endoscopic resection of early esophageal squamous neoplasia showed that MBM was effective for the complete removal of lesions with short procedure time, few complications, effective histological assessment of resected specimens, and durable treatment effect.

Functional single nucleotide polymorphism in C20orf54 modifies susceptibility to esophageal squamous cell carcinoma

The aim of this study was to explore the association of C20orf54 functional single nucleotide polymorphism (SNP) with the susceptibility to esophageal squamous cell carcinoma (ESCC) in a northern China population. The C20orf54 SNP was genotyped by direct sequencing in 240 cancer patients and 198 controls in northern China. The results showed that drinking status, family history of ESCC, and body mass index have great influence on the risk of developing ESCC. The overall genotype frequencies of C20orf54 in ESCC patients have a significant difference with healthy controls (χ(2)  = 8.06, P = 0.018). By using C/C genotype as the reference, the C/T genotype showed a significantly decreased risk to the development of ESCC. Thus, compared with the C/C genotype, smokers, drinkers with C/T genotype significantly decreased the risk of developing ESCC. A positive family history of ESCC with C/T and T/T genotype both increased the risk of developing ESCC. Body mass index between 18.5 and 24 with C/T genotype significantly decreased the risk of developing ESCC. The present study suggests that the C20orf54 functional SNP might be associated with a risk of development in ESCC.

Effect of salinity on the bioremediation of petroleum hydrocarbons in a saline-alkaline soil

AIMS

 The aim of this paper is to check the effect of salinity on the bioremediation process of petroleum hydrocarbons in the saline-alkaline soil.

METHODS AND RESULTS

 In this study, soil salinity was adjusted to different levels by water leaching method and the bioremediation process was conducted for 28 days. Soil pH increased after leaching and decreased during bioremediation process. At initial time, moderate salinity enhanced the biodegradation and addition of microbial consortium was not effective in enhancing degradation rate of petroleum hydrocarbons. At day of 28 days, higher degradation rate was found in treatments with more leaching times with a maximum value of 42·36%. Dehydrogenase activity increased with the progress of bioremediation and positive correlation was found between dehydrogenase activity and degradation rate of petroleum hydrocarbons. Denaturing gradient gel electrophoresis analysis result showed decreased microbial community diversity with increased salt content.

CONCLUSIONS

 The result suggested that salinity had great impact on bioremediation, and leaching and addition of inoculated consortium were effective in enhancing biodegradation of petroleum hydrocarbons in the saline-alkaline soil.

SIGNIFICANCE AND IMPACT OF THE STUDY

 The result of this study is important for understanding the bioremediation process of petroleum in contaminated soil. New remediation method of petroleum contaminated soil can be developed based on this study.

Efficacy of folic acid supplementation in stroke prevention: new insight from a meta-analysis

AIMS

  There are growing data and a continuing controversy over the efficacy of folic acid supplementation in stroke prevention. We conducted a meta-analysis based on relevant, up-to-date published randomised trials to further examine this issue.

METHODS

  Relative risk (RR) was used to measure the effect of folic acid supplementation on risk of stroke with a fixed-effects model.

RESULTS

  Overall, folic acid supplementation reduced the risk of stroke by 8% (n = 55,764; RR: 0.92; 95% CI: 0.86-1.00, p = 0.038). In the 10 trials with no or partial folic acid fortification (n = 43,426), the risk of stroke was reduced by 11% (0.89; 0.82-0.97, p = 0.010). Within these trials, a greater beneficial effect was observed among trials with a lower percent use of statins [≤ 80% (median); 0.77; 0.64-0.92, p = 0.005], and a meta-regression analysis also suggested a positive dose-response relationship between percent use of statins and log-RR for stroke associated with folic acid supplementation (p = 0.013). A daily dose of 0.4-0.8mg folic acid appeared to be adequate for stroke prevention in comparison with larger doses. In the remaining five trials conducted in populations with folic acid fortification (n = 12,338), folic acid supplementation had no effect on stroke risk (1.03; 0.88-1.21, 0.69).

CONCLUSIONS

  Our analysis indicated that folic acid supplementation is effective in stroke prevention in populations with no or partial folic acid fortification. In addition, a greater beneficial effect was observed among trials with a lower percent use of statins. Our findings underscore the importance of identifying target populations that can particularly benefit from folic acid therapy.

Reliable high-throughput approach for screening of engineered constitutive promoters in the yeast Pichia pastoris

AIMS

To develop a reliable and sensitive high-throughput approach for the screening of engineered constitutive promoters in the yeast Pichia pastoris.

METHODS AND RESULTS

The yeast-enhanced green fluorescent protein (yEGFP) was used as the reporter to monitor the promoter strength. After eliminating the interfering components (yeast extract and tryptone) with fluorescence signal from the medium, a high-throughput screening approach was established and optimized to obtain a low standard deviation of cell density (6.9%) and fluorescence (7.4%) in 48-deep-well microplates. Then, 300 clones containing GAP promoter (P(GAP)) variants were screened, exhibiting a wide range in fluorescent intensity from about 8% to 218% of that obtained with P(GAP). Six representative clones with unique promoter sequence were picked for further characterization. A good correlation between yEGFP fluorescence in microplates and shake flasks was observed. Furthermore, the high correlation between fluorescence and transcript levels confirmed that expression was transcriptionally controlled.

CONCLUSIONS

We developed a reliable high-throughput screening approach that can be used to select engineered constitutive promoters of varying strengths.

SIGNIFICANCE AND IMPACT OF THE STUDY

This approach is expected to accelerate the selection of constitutive promoters in P. pastoris and can also be applied for the screening of other constitutive expression clones.

Erythromycin inhibited glycinergic inputs to gastric vagal motoneurons in brainstem slices of newborn rats

BACKGROUND

Motilin has been known to stimulate the motility of digestive organs peripherally via activation of motilin receptors located at gastrointestinal (GI) cholinergic nerve endings and/or smooth muscle cells. Recent studies have indicated that motilin may also promote GI motility via actions in the central nervous system; however the sites of action and the mechanisms are not clear yet. The present study aimed to test the hypothesis that motilin receptor agonist erythromycin alters the synaptic inputs of preganglionic gastric vagal motoneurons (GVMs) located in the dorsal motor nucleus of the vagus (DMV).

METHODS

Gastric vagal motoneurons were retrogradely labeled by fluorescent tracer from the stomach wall of newborn rats. Fluorescently labeled GVMs in DMV were recorded using whole-cell patch-clamp in brainstem slices and the effects of motilin receptor agonist erythromycin on the synaptic inputs were examined.

KEY RESULTS

Erythromycin (100 nmol L(-1), 1 μmol L(-1), 10 μmol L(-1)) significantly inhibited the frequency of glycinergic spontaneous inhibitory postsynaptic currents (sIPSCs) of GVMs and significantly inhibited the amplitude at the concentration of 10 μmol L(-1). These responses were prevented by GM-109, a selective motilin receptor antagonist. In the pre-existence of tetradotoxin (TTX, 1 μmol L(-1)), erythromycin (10 μmol L(-1)) caused significant decreases of the glycinergic miniature inhibitory postsynaptic currents (mIPSCs), in both the frequency and the amplitude. However, erythromycin (10 μmol L(-1)) didn't cause significant changes of the GABAergic sIPSCs.

CONCLUSIONS & INFERENCES

Erythromycin selectively inhibits the glycinergic inputs of GVMs.

Cisplatin induces programmed death-1-ligand 1(PD-L1) over-expression in hepatoma H22 cells via Erk /MAPK signaling pathway

Cisplatin has been widely used in cancer treatment. However, the prognosis of the cancer patients following chemotherapy has not been substantially improved and several different mechanisms could be involved. Clinically alternative strategies such as immunotherapy and their combinations with chemotherapy have being used. Cancer immunoresistance and immune escape are major obstacles in chemotherapy. However, the effects of cisplatin on the immune responses of cancer cells are not clear. In the present studies, we investigate the expression of immunoresistance moleculor PD-L1 (the negative regulator programmed death-1-ligand 1) on cisplatin-induced hepatoma H22 cells, which can interact with PD-1 on T cells to mediate cancer immunoresistance. Hepatoma H22 cells were treated with cisplatin in vivo or in vitro to analysis the expression of PD-L1 by flow cytometry (FACS). Erk1/Erk2 phosphorylation expressions were examined by western blotting. We demonstrated that cisplatin was able to induce H22 cell apoptosis and when the concentration less than IC50 cisplatin could up-regulate PD-L1 expression in hepatoma H22 cells. The optimal concentration of cisplatin for the highest expression of PD-L1 was 0.5 μg/ml in vitro. Meanwhile, cisplatin could induce the phosphorylation of Erk1/2.The lack of effect during treatment with a specific MAPK pathway inhibitor PD98059, demonstrated that cisplatin-induced PD-L1 expression is dependent of Erk1/2 phosphorylation. Our studies reveal a potential link between chemotherapy and cancer immunoresistance. PD-L1 and its signaling pathway appear to be a potential therapeutic target for the cisplatin treatment of hepatoma.

RKTG inhibits angiogenesis by suppressing MAPK-mediated autocrine VEGF signaling and is downregulated in clear-cell renal cell carcinoma

Vascular endothelial growth factors (VEGFs) are crucial regulators of angiogenesis and vasculogenesis. The autocrine VEGF signaling is required for maintaining the homeostasis of vasculature. Dysregulation of angiogenesis is implicated in the development of many human cancers, especially in clear-cell renal cell carcinoma (ccRCC), a highly vascularized tumor. Meanwhile, antiangiogenesis has become a mainstay in the treatment of human cancers. In this study, we analyzed the functional roles of RKTG (Raf Kinase Trapping to Golgi), a negative regulator of mitogen-activated protein kinase (Raf/MEK/ERK) signaling, by sequestration of Raf kinase to the Golgi apparatus, in angiogenesis and ccRCC. Through a series of in vitro and in vivo experiments, we found that RKTG has a negative effect on cell proliferation, migration, sprouting and angiogenesis of endothelial cells. RKTG, by suppressing mitogen-activated protein kinase signaling, negatively regulates the transactivation activity of hypoxia-inducible factor 1α (HIF-1α) by inhibiting formation of HIF-1α/p300 complex and suppressing VEGF transcription, thereby reducing hypoxia-induced VEGF production. The expression level of RKTG is significantly downregulated in clinical ccRCC tumor samples, with an inverse correlation with VEGF expression level. These results highlight the functional roles of RKTG and its regulated Raf/ERK/MEK signaling cascade in angiogenesis and autocrine VEGF signaling. In addition, this study indicates that RKTG is likely implicated in the development of ccRCC through its regulation on angiogenesis.

Detection of PCR products using self-reporting duplex mutation primers

A novel oligonucleotide probe, with duplex mutation primers, which comprised a normal reverse primer labelled with a fluorophore at its 5'-end and a single-base mismatched complementary oligonucleotide labelled with a quencher at its 3'-end, was designed. Its application in the detection of hepatitis B virus (HBV) DNA of serum was investigated; results were compared with those obtained using a commercial TaqMan kit. There was a good linear correlation in the range of 10(2) approximately 10(7) copies/ml (r(2) = 0.999) with the method. Intra-experimental coefficients of variation (CVs) were 0.70% approximately 7.80%, and inter-experimental CVs were 0.78% approximately 9.02%, respectively. There was no significant difference of HBV genome number tested by the two methods (p<0.05) in 132 hepatitis B patients; HBV DNA was not detected in any serum samples of 20 healthy volunteers by the two methods.

Waist circumference, body mass index and waist to hip ratio for prediction of the metabolic syndrome in Chinese

BACKGROUND AND AIMS

To explore the ability of waist circumference (WC), body mass index (BMI) and waist to hip ratio (WHR) to predict two or more non-adipose components of the metabolic syndrome (MetS) among individuals aged 18-85 in North China.

METHODS AND RESULTS

This study is a cluster sample survey of 101,510 individuals, complete data are 75,788 subjects, 59,874 males and 15,914 females. Their ages were 51.9+/-12.7 years (males) and 48.7+/-11.5 years (females). Receiver operating characteristic (ROC) analysis was used to examine discrimination and find optimal cut off values of WC, BMI and WHR to predict two or more non-adipose components of MetS. The area under the ROC curve (AURC) for WC (0.694) and BMI (0.692) in females showed no difference. In males BMI (0.657) had a better discrimination than WC (0.634). WHR was weaker in both sexes. The optimal cut off value of WC in males (86.5 cm) was higher than in females (82.1cm); and that of BMI was about 24 kg/m(2) in both genders. The optimal cut off values of WC, BMI, and WHR, increased with age in both sexes.

CONCLUSIONS

BMI and WC are more useful than WHR for predicting two or more non-adipose components of MetS. Cut off values for WC in males, and those of BMI and WHR in both sexes are lower than that in present MetS criteria; WC in females is slightly higher. Cut off values of WC, BMI and WHR were increased with age in the Chinese.