A two-sample bidirectional Mendelian randomization analysis investigates associations between gut microbiota and type 2 diabetes mellitus

Objective

This study sought to elucidate the causal association between gut microbiota (GM) composition and type 2 diabetes mellitus (T2DM) through a comprehensive two-sample bidirectional Mendelian randomization analysis.

Method

T2DM data were sourced from the IEU OpenGWAS Project database, complemented by 211 gut microbiota (GM) datasets from the MiBioGen Federation. The primary analytical approach employed was inverse variance weighted (IVW), supplemented by MR-Egger regression and weighted median (WME) methods to investigate their potential interplay. Results were assessed using odds ratios (OR) and 95% confidence intervals (CI). The robustness and reliability of the findings were confirmed through leave-one-out analysis, heterogeneity testing, and assessment of horizontal pleiotropy. Furthermore, we explored the potential mediating role of metabolites in the pathway linking GM to T2DM.

Result

A set of 11 Single Nucleotide Polymorphisms (SNPs) linked to GM were identified as instrumental variables (IVs). The IVW analysis revealed that increased abundance of the genus Actinomyces, genus Bilophila, genus Lachnoclostridium, genus Ruminococcus gnavus group, and genus Streptococcus corresponded to a heightened risk of T2DM. Conversely, higher levels of genus Eubacterium oxidoreducens group, genus Oscillospira, genus Ruminococcaceae UCG003, genus Ruminococcaceae UCG010, and genus Sellimonas were associated with a reduced risk of T2DM. However, following false discovery rate (FDR) correction, only the abundance of genus Lachnoclostridium retained a significant positive correlation with T2DM risk (OR = 1.22, q value = 0.09), while the other ten GM showed suggestive associations with T2DM. Reverse MR analysis did not reveal any causal relationship between T2DM and the increased risk associated with the identified GM. Additionally, metabolites did not exhibit mediating effects in this context.

Conclusion

This study effectively pinpointed specific GM associated with T2DM, potentially paving the way for novel biomarkers in the prevention and treatment of this condition. The findings suggested that probiotics could emerge as a promising avenue for managing T2DM in the future. Furthermore, the analysis indicated that metabolites do not appear to act as mediators in the pathway from GM to T2DM.

Phosphorylation: new star of pathogenesis and treatment in steatotic liver disease

Steatotic liver disease poses a serious threat to human health and has emerged as one of the most significant burdens of chronic liver disease worldwide. Currently, the research mechanism is not clear, and there is no specific targeted drug for direct treatment. Phosphorylation is widely regarded as the most common type of protein modification, closely linked to steatotic liver disease in previous studies. However, there is no systematic review to clarify the relationship and investigate from the perspective of phosphorylation. Phosphorylation has been found to mainly regulate molecule stability, affect localization, transform molecular function, and cooperate with other protein modifications. Among them, adenosine 5'-monophosphate-activated protein kinase (AMPK), serine/threonine kinase (AKT), and nuclear factor kappa-B (NF-kB) are considered the core mechanisms in steatotic liver disease. As to treatment, lifestyle changes, prescription drugs, and herbal ingredients can alleviate symptoms by influencing phosphorylation. It demonstrates the significant role of phosphorylation as a mechanism occurrence and a therapeutic target in steatotic liver disease, which could be a new star for future exploration.

The metabolic profiles and body composition of non-obese metabolic associated fatty liver disease

Background/purpose

Metabolic-associated fatty liver disease (MAFLD) is a major cause of chronic liver disease worldwide and is generally thought to be closely related to obesity and diabetes. However, it also affects non-obese individuals, particularly in Asian cultures.

Methods

Healthy physical examination subjects and MAFLD patients were included in the endocrinology department of Jiangsu Provincial Hospital of Traditional Chinese Medicine. MAFLD was defined as fatty liver in imaging without virus infection, drug, alcohol, or other known causes of chronic liver disease. Non-obese MAFLD was defined as MAFLD in non-obese subjects (BMI<25 kg/m2).

Results

The final analysis comprised 1047 participants in total. Of 946 MAFLD patients, 162 (17.12%) were diagnosed with non-obese MAFLD. Non-obese MAFLD patients were older, had lower alanine aminotransferase (ALT), triglyceride, and waist circumference, but had higher high density lipoprotein cholesterol (HDL-c) than obese MAFLD patients. Compared with non-obese healthy controls, non-obese MAFLD patients had higher BMI, ALT, gamma-glutamyl transferase (GGT), uric acid (UA), triglycerides (TG), and low density lipoprotein cholesterol (LDL-c). In terms of body composition, body fat mass (BFM), waist-hip ratio (WHR), percent body fat (PBF), visceral fat area (VFA), and fat mass index (FMI) were lower in non-obese healthy controls than non-obese MAFLD patients. A binary logistic regression analysis revealed that non-obese MAFLD was linked with lower GGT and higher HDL-c.

Conclusion

In this study cohort, non-obese MAFLD was present at a prevalence of 13.90%. In contrast to non-obese healthy controls, non-obese MAFLD patients exhibited different metabolic profiles, but they also had different body compositions.

[Determination of 4-methyl-2-pentanol in workplace air by solvent desorption-gas chromatography]

Objective: To establish a method for the determination of 4-methyl-2-pentanol in the air of workplace by gas chromatography. Methods: In January 2022, 4-methyl-2-pentanol in the air of workplace was collected by activated carbontube, eluted with dichloromethane-methanol (95∶5, V/V), separated by capillary column and determined by gas chromatogram. Results: The limit of detection for 4-methyl-2-pentanol was 0.04 μg/ml. The linear range of 4-methyl-2-pentanol was 0.16-1616.60 μg/ml, with the regression equation of y=1.94x-5.48, and the coefficient correlation was 0.99958, and the minimum detection concentration was 0.03 mg/m(3) (collected sample volume was 1.50 L). The within-run precisions were 1.08%-1.75% and the between-run precisions were 1.41%-2.52%. The desorption rates were 95.15%-99.91%. The samples could be stored at least 3 days at room temperature and 7 days at 4 ℃ without significant loss. Conclusion: The method has the advantages of good precision, high sensitivity and simple operation. It is suitable for the determination of 4-methyl-2-pentanol in the air of workplace.

Corrigendum: GLP-1RAs caused gastrointestinal adverse reactions of drug withdrawal: a system review and network meta-analysis

[This corrects the article DOI: 10.3389/fendo.2023.1149328.].

Corrigendum: The value of functional magnetic resonance imaging in the evaluation of diabetic kidney disease: a systematic review and meta-analysis

[This corrects the article DOI: 10.3389/fendo.2023.1226830.].

The value of functional magnetic resonance imaging in the evaluation of diabetic kidney disease: a systematic review and meta-analysis

Background

The diversity of clinical trajectories in diabetic kidney disease (DKD) has made blood and biochemical urine markers less precise, while renal puncture, the gold standard, is almost impossible in the assessment of diabetic kidney disease, and the value of functional magnetic resonance imaging in the evaluation of diabetic pathological alterations is increasingly recognized.

Methods

The literature on functional magnetic resonance imaging (fMRI) for the assessment of renal alterations in diabetic kidney disease was searched in PubMed, Web of Science, Cochrane Library, and Embase databases. The search time limit is from database creation to March 10, 2023. RevMan was used to perform a meta-analysis of the main parameters of fMRIs extracted from DKD patients and healthy volunteers (HV).

Results

24 publications (1550 subjects) were included in this study, using five functional MRIs with seven different parameters. The renal blood flow (RBF) values on Arterial spin labeling magnetic resonance imaging (ASL-MRI) was significantly lower in the DKD group than in the HV group. The [WMD=-99.03, 95% CI (-135.8,-62.27), P<0.00001]; Diffusion tensor imaging magnetic resonance imaging (DTI-MRI) showed that the fractional anisotropy (FA) values in the DKD group were significantly lower than that in HV group [WMD=-0.02, 95%CI (-0.03,-0.01), P<0.0001]. And there were no statistically significant differences in the relevant parameters in Blood oxygen level-dependent magnetic resonance imaging (BOLD-MRI) or Intro-voxel incoherent movement magnetic resonance imaging (IVIM-DWI).

Discussion

ASL and DWI can identify the differences between DKD and HV. DTI has a significant advantage in assessing renal cortical changes; IVIM has some value in determining early diabetic kidney disease from the cortex or medulla. We recommend combining multiple fMRI parameters to assess structural or functional changes in the kidney to make the assessment more comprehensive. We did not observe a significant risk of bias in the present study.

Systematic review registration

https://www.crd.york.ac.uk, identifier CRD42023409249.

GLP-1RAs caused gastrointestinal adverse reactions of drug withdrawal: a system review and network meta-analysis

Background

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) significantly reduce postprandial blood glucose, inhibit appetite, and delay gastrointestinal emptying. However, it is controversial that some patients are intolerant to GLP-1RAs.

Methods

PubMed, Embase, Web of Science, and Cochrane Library were searched for randomized controlled trials (RCTs) using GLP-1RAs with documented withdrawal due to gastrointestinal adverse reactions (GI AEs) from their inception to September 28, 2022. After extracting the information incorporated into the studies, a random-effects network meta-analysis was performed within a frequentist framework.

Results

64 RCTs were finally enrolled, which included six major categories of the GLP-1RA. The sample size of the GLP-1RAs treatment group was 16,783 cases. The risk of intolerable gastrointestinal adverse reactions of Liraglutide and Semaglutide was higher than that of Dulaglutide. Meanwhile, the higher the dose of the same GLP-1RA preparation, the more likely to cause these adverse reactions. These intolerable GI AEs were not significantly related to drug homology or formulations and may be related to the degree of suppression of the appetite center.

Conclusion

Dulaglutide caused the lowest intolerable GI AEs, while Liraglutide and Semaglutide were the highest. For Semaglutide, the higher the dose, the more likely it is to drive GI AEs. Meanwhile, the risk of these GI AEs is independent of the different formulations of the drug. All these findings can effectively guide individualized treatment.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022359346, identifier CRD42022359346.

Huobahuagen tablet improves renal function in diabetic kidney disease: a real-world retrospective cohort study

Objective

We aimed to explore the value of Huobahuagen tablet (HBT) in improving decreased renal function for patients with diabetic kidney disease (DKD) over time.

Methods

This was a single-center, retrospective, real-world study on eligible 122 DKD patients who continued to use HBT + Huangkui capsule (HKC) therapy or HKC therapy without interruption or alteration in Jiangsu Province Hospital of Chinese Medicine from July 2016 to March 2022. The primary observation outcomes included estimated glomerular filtration rate (eGFR) at baseline and 1-, 3-, 6-, 9-, and 12-month follow-up visits and changes in eGFR from baseline (ΔeGFR). Propensity score (PS) and inverse probability treatment weighting (IPTW) were used to control for confounders.

Results

eGFR was significantly higher in the HBT + HKC group than in the HKC alone group at the 6-, 9-, and 12-month follow-up visits (p = 0.0448, 0.0002, and 0.0037, respectively), indicating the superiority of HBT + HKC over HBT alone. Furthermore, the ΔeGFR of the HBT + HKC group was significantly higher than that of the HKC alone group at the 6- and 12-month follow-up visits (p = 0.0369 and 0.0267, respectively). In the DKD G4 patients, eGFR was higher in the HBT + HKC group at the 1-, 3-, 6-, 9-, and 12-month follow-up visits compared with baseline, with statistically significant differences at the 1-, 3-, and 6- month follow-up visits (p = 0.0256, 0.0069, and 0.0252, respectively). The fluctuations in ΔeGFR ranged from 2.54 ± 4.34 to 5.01 ± 5.55 ml/min/1.73 m². Change in the urinary albumin/creatinine ratio from baseline did not exhibit a significant difference between the two groups at any of the follow-up visits (p > 0.05 for all). Adverse event incidence was low in both groups.

Conclusion

The findings of this study based on real-world clinical practice indicate that HBT + HKC therapy exhibited better efficacy in improving and protecting renal function with a favorable safety profile than HKC therapy alone. However, further large-scale prospective randomized controlled trials are warranted to confirm these results.

Timing of endoscopy for acute variceal bleeding in patients with cirrhosis (CHESS1905): A nationwide cohort study

BACKGROUND

Endoscopy plays an important role in the management of acute variceal bleeding (AVB) in patients with cirrhosis. This study aimed at determining the optimal endoscopy timing for cirrhotic AVB.

METHODS

Patients with cirrhosis with AVB across 34 university hospitals in 30 cities from February 2013 to May 2020 who underwent endoscopy within 24 hours were included in this study. Patients were divided into an urgent endoscopy group (endoscopy <6 h after admission) and an early endoscopy group (endoscopy 6-24 h after admission). Multivariable analysis was performed to identify risk factors for treatment failure. Primary outcome was the incidence of 5-day treatment failure. Secondary outcomes included in-hospital mortality, need for intensive care unit, and length of hospital stay. A propensity score matching analysis was performed. In addition, we performed an analysis, in which we compared the 5-day treatment failure incidence and the in-hospital mortality among patients with endoscopy performed at <12 hours and 12-24 hours.

RESULTS

A total of 3319 patients were enrolled: 2383 in the urgent endoscopy group and 936 in the early endoscopy group. After propensity score matching, on multivariable analysis, Child-Pugh class was identified as an independent risk factor for 5-day treatment failure (HR, 1.61; 95% CI: 1.09-2.37). The incidence of 5-day treatment failure was 3.0% in the urgent endoscopy group and 2.9% in the early group ( p = 0.90). The in-hospital mortality was 1.9% in the urgent endoscopy group and 1.2% in the early endoscopy group ( p = 0.26). The incidence of need for intensive care unit was 18.2% in the urgent endoscopy group and 21.4% in the early endoscopy group ( p = 0.11). The mean length of hospital stay was 17.9 days in the urgent endoscopy group and 12.9 days in the early endoscopy group ( p < 0.05). The incidence of 5-day treatment failure in the <12-hour group was 2.3% and 2.2% in the 12-24 hours group ( p = 0.85). The in-hospital mortality was 2.2% in the <12-hour group and 0.5% in the 12-24 hours group ( p < 0.05).

CONCLUSIONS

The data suggest that performance of endoscopy within 6-12 or within 24 hours of presentation among patients with cirrhosis with AVB led to similar treatment failure outcomes.

Effects of SGLT2 inhibitors on hepatic fibrosis and steatosis: A systematic review and meta-analysis

OBJECTIVE

Clinical trials have shown that sodium-glucose cotransporter 2 inhibitors (SGLT2i) are closely associated with hepatic fibrosis and steatosis by FibroScan. This paper aimed at evaluating the effects of SGLT2i on hepatic fibrosis and steatosis, which are presented as liver stiffness measurement (LSM) and controlled attenuation parameter (CAP).

METHODS

PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure Database, China Science and Technology Journal Database, and Wanfang Database were searched for randomized clinical trials from database establishment to 30 November 2022 with no language restrictions. The risk of bias was evaluated by Collaboration Handbook. Software Stata 17 and Review Manager (version 5.3) were used for meta-analysis.

RESULTS

A total of eight articles including 686 patients were included. Compared with the control group, our results showed that SGLT2i could lower levels of LSM [MD = -0.82, 95%CI (-1.38, -0.25), p = 0.005] and CAP [MD = -12.80, 95%CI (-20.57, -5.03), p = 0.001]. Further subgroup analyses indicated that SGLT2i presented more advantages on longer treatment duration and more serious steatosis in decreasing LSM. For CAP, SGLT2i exhibited a clear advantage in subgroup analyses of longer treatment duration, younger people, dapagliflozin, worse fibrosis, and steatosis.

CONCLUSION

SGLT2i could reduce LSM and CAP in contrast to other antihyperglycemic drugs. However, the included studies are not definitive, and well-designed, more multi-centered, blinded randomized clinical trials are warranted to definitively establish reliable evidence.

[Determination of acetylacetone in workplace air by solvent desorption-gas chromatography]

Objective: To establish a method for the determination of acetylacetone in the air of workplace by gas chromatography. Methods: In August 2020, acetylacetone in the air of workplace was collected by silica gel tube, eluted with methanol, separated and detected by gas chromatography with flame ionization detector. The detection limit and precision of the method were also analyzed. Results: The linear range of acetylacetone was 1.95-1950.60 μg/ml with the regression equation of y=0.815x-3.667, and the correlation coefficient was 0.99993. The limit of detection of the method was 0.18 μg/ml and the minimum detection concentration was 0.12 mg/m(3) (collected sample volume was 1.50 L). The within-run precisions were 1.08%-4.11% and the between-run precisions were 1.98%-2.80%. The desorption rates were 99.68%-100.45%. The sealed samples could be kept at least 15 days at room temperature without significant loss. Conclusion: The solvent desorption-gas chromatography method for the determination of acetylacetone has good precision, high sensitivity and simple operation, and is suitable for the determination of acetylacetone in the air of the workplace.

[Bacterial community diversity in Dermatophagoides farinae using high-throughput sequencing]

OBJECTIVE

To investigate the bacterial community diversity in Dermatophagoides farinae.

METHODS

Laboratory-cultured D. farinae was collected, and the composition of microbial communities was determined by sequence analyses of the V4 region in the bacterial 16S ribosomal RNA (16S rRNA) gene on an Illumina PE250 high-throughput sequencing platform. Following quality control and filtering of the raw sequence files, valid reads were obtained and subjected to operational taxonomic units (OTU) clustering and analysis of the composition of microbial communities and alpha diversity index using the Usearch software, Silva database, and Mothur software.

RESULTS

A total of 187 616 valid reads were obtained, and 469 OTUs were clustered based on a sequence similarity of more than 97%. OTU annotation showed that the bacteria in D. farinae belonged to 26 phyla, 43 classes, 100 orders, 167 families and 284 genera. The bacteria in D. farinae were mainly annotated to five phyla of Proteobacteria, Firmicutes, Bacteroidota, Actinobacteriota, and Acidobacteriota, with Proteobacteria as the dominant phylum, and mainly annotated to five dominant genera of Ralstonia, norank-f-Mitochondria, Staphylococcus and Sphingomonas, with Wolbachia identified in the non-dominant genus.

CONCLUSIONS

A high diversity is identified in the composition of the bacterial community in D. farinae, and there are differences in bacterial community diversity and abundance among D. farinae.

[Screening, functional analysis and clinical validation of differentially expressed genes in diabetic foot ulcers]

Objective: To screen the differentially expressed genes (DEGs) in diabetic foot ulcers (DFUs), and to perform functional analysis and clinical validation of them, intending to lay a theoretical foundation for epigenetic therapy of chronic refractory wounds. Methods: An observational study was conducted. The gene expression profile dataset GSE80178 of DFU patients in Gene Expression Omnibus (GEO) was selected, and the DEG between three normal skin tissue samples and six DFU tissue samples in the dataset was analyzed and screened using the GEO2R tool. For the screened DEG, ClusterProfiler, org.Hs.eg.db, GOplot, and ggplot2 in the R language packages were used for Gene Ontology (GO) enrichment analysis of biological processes, molecular functions, and cellular components, and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, respectively. Protein-protein interaction (PPI) analysis was performed using STRING database to screen key genes in the DEG, and GO enrichment analysis of key genes was performed using Cytohubba plug-in in Cytoscape 3.9.1 software. DFU tissue and normal skin tissue discarded after surgery were collected respectively from 15 DFU patients (7 males and 8 females, aged 55-87 years) and 15 acute wound patients (6 males and 9 females, aged 8-52 years) who were admitted to Xiang'an Hospital of Xiamen University from September 2018 to March 2021. The mRNA and protein expressions of small proline-rich repeat protein 1A (SPRR1A) and late cornified envelope protein 3C (LCE3C) were detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction and immunohistochemistry, respectively. Data were statistically analyzed with independent sample t test. Results: Compared with normal skin tissue, 492 statistically differentially expressed DEGs were screened from DFU tissue of DFU patients (corrected P<0.05 or corrected P<0.01), including 363 up-regulated DEGs and 129 down-regulated DEGs. GO terminology analysis showed that DEGs were significantly enriched in the aspects of skin development, keratinocyte (KC) differentiation, keratinization, epidermal development, and epidermal cell differentiation, etc. (corrected P values all <0.01). KEGG pathway analysis showed that DEGs were significantly enriched in the aspects of tumor-associated microRNA, Ras related protein 1 signaling pathway, and pluripotent stem cell regulatory signaling pathway, etc. (corrected P values all <0.01). PPI analysis showed that endophial protein, SPRR1A, SPRR1B, SPRR2B, SPRR2E, SPRR2F, LCE3C, LCE3E, keratin 16 (all down-regulated DEGs), and filoprotein (up-regulated DEG) were key genes of DEGs screened from DFU tissue of DFU patients, which were significantly enriched in GO terms of keratinization, KC differentiation, epidermal cell differentiation, skin development, epidermis development, and peptide cross-linking, etc. (corrected P values all <0.01). The mRNA expressions of SPRR1A and LCE3C in DFU tissue of DFU patients were 0.588±0.082 and 0.659±0.098, respectively, and the protein expressions were 0.22±0.05 and 0.24±0.04, respectively, which were significantly lower than 1.069±0.025 and 1.053±0.044 (with t values of 20.91 and 13.66, respectively, P values all <0.01) and 0.38±0.04 and 0.45±0.05 (with t values of 9.69 and 12.46, respectively, P values all <0.01) in normal skin tissue of acute wound patients. Conclusions: Compared with normal skin tissue, there is DEG profile in DFU tissue of DFU patients, with DEGs being significantly enriched in the aspects of KC differentiation and keratin function. Key DEGs are related to the biological function of KC, and their low expressions in DFU tissue of DFU patients may impede ulcer healing.

Efficacy and safety of Abelmoschus moschatus capsules combined with tripterygium glycoside tablets on diabetic nephropathy: A systematic review and meta-analysis

Background: Diabetic nephropathy (DN) is one of the most serious chronic micro-vascular complications of diabetes and the leading cause of end-stage kidney disease (ESRD) worldwide, with reduced expectancy and quality of life and colossal financial and social burden worldwide. In spite of emerging treatments on DN, effective therapy on delaying the progression of DN is still lacking. In clinical practice, there are many studies focusing on Abelmoschus moschatus (AM) capsules together with Tripterygium glycoside (TG) tablets in the treatment of DN, and excellent results have been obtained.

Objective: The study aimed to evaluate the efficacy and safety of AM combined with TG in the treatment of DN.

Methods: Databases including PubMed, Web of Science, Cochrane Library, Embase, CNKI, WF, and VIP were searched from their inception to 1 March 2022. The “risk of bias” evaluation tool produced by the Cochrane Collaboration Handbook was used for evaluating the quality of the included studies. Revman 5.3 software was used for meta-analysis.

Results: Here, 11 studies with a total of 1,072 participants were included for this meta-analysis. Our results showed that AM combined with TG plus basic treatment could lower levels of 24 h-UP [MD = -0.18; 95% CI: (-0.21, -0.14); p < 0.00001], Scr [MD = -15.29; 95% CI: (-28.69, -1.88); p = 0.03], and BUN [MD = -1.18; 95% CI: (-1.69, -0.68); p < 0.00001]. Meanwhile, the adverse reaction rate increased in the combination group [RR = 1.88; 95% CI (1.26, 2.82); p = 0.002].

Conclusion: Current evidence suggests that AM combined with TG may be more effective in the treatment of DN, which will be highly beneficial to further theoretical discussion and practical clinical applications. However, the safety cannot be ignored because of nearly increasing 2-fold adverse events, although they can be mitigated through systematic treatment. Meanwhile, due to low quality of the included studies, great possibility of publication bias, and large heterogeneity among different studies, the results of our review should be evaluated with more prudence and high-quality RCTs are warranted to confirm this in the future.

Systematic review Registration:www.crd.york.ac.uk, identifier CRD42022344359.

Accuracy of controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) for assessing steatosis and fibrosis in non-alcoholic fatty liver disease: A systematic review and meta-analysis

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver disease, and among the non-invasive tests, controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) have shown better diagnostic performance in NAFLD. This meta-analysis aimed to evaluate the performance of CAP and LSM for assessing steatosis and fibrosis in NAFLD.

METHODS

We searched the PubMed, Web of Science, Cochrane Library, and Embase databases for relevant articles published up to February 13^th, 2022, and selected studies that met the inclusion and exclusion criteria, and evaluated the quality of evidence. Then we pooled sensitivity (SE), specificity (SP), and area under receiver operating characteristic (AUROC) curves. A random effect model was applied regardless of heterogeneity. Meta-regression analysis and subgroup analysis were performed to explore heterogeneity, and Fagan plot analysis was used to evaluate clinical utility. This meta-analysis was completed in Nanjing, Jiangsu and registered on PROSPERO (CRD42022309965).

FINDINGS

A total of 10537 patients from 61 studies were included in our meta-analysis. The AUROC of CAP were 0·924, 0·794 and 0·778 for steatosis grades ≥ S1, ≥ S2 and = S3, respectively, and the AUROC of LSM for detecting fibrosis stages ≥ F1, ≥ F2, ≥ F3, and = F4 were 0·851, 0·830, 0·897 and 0·925, respectively. Subgroup analysis revealed that BMI ≥ 30 kg/m² had lower accuracy for diagnosing S ≥ S1, ≥ S2 than BMI<30 kg/m². For the mean cut-off values, significant differences were found in CAP values among different body mass index (BMI) populations and LSM values among different regions. For diagnosing S ≥ S1, ≥ S2 and = S3, the mean CAP cut-off values for BMI ≥ 30 kg/m² were 30·7, 28·2, and 27·9 dB/m higher than for BMI < 30 kg/m² (P = 0·001, 0·001 and 0·018, respectively). For diagnosing F ≥ F2 and = F4, the mean cut-off values of Europe and America were 0·96 and 2·03 kPa higher than Asia (P = 0·027, P = 0·034), respectively. In addition, the results did not change significantly after sensitivity analysis and the trim and fill method to correct for publication bias, proving that the conclusions are robust.

INTERPRETATION

The good performance of CAP and LSM for the diagnosis of mild steatosis (S ≥ S1), advanced liver fibrosis (F ≥ F3), and cirrhosis (F = F4) can be used to screen for NAFLD in high-risk populations. Of note, the accuracy of CAP for the detection of steatosis in patients with obesity is reduced and requires specific diagnostic values. For LSM, the same diagnostic values can be used when the appropriate probes are selected based on BMI and the automated probe selection tool. The performance of CAP and LSM in assessing steatosis in patients with obesity, moderate to severe steatosis, and low-grade fibrosis should be further validated and improved in the future.

FUNDING

The study was funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).

Iptakalim improves cerebral microcirculation in mice after ischemic stroke by inhibiting pericyte contraction

Pericytes are present tight around the intervals of capillaries, play an essential role in stabilizing the blood-brain barrier, regulating blood flow and immunomodulation, and persistent contraction of pericytes eventually leads to impaired blood flow and poor clinical outcomes in ischemic stroke. We previously show that iptakalim, an ATP-sensitive potassium (K-ATP) channel opener, exerts protective effects in neurons, and glia against ischemia-induced injury. In this study we investigated the impacts of iptakalim on pericytes contraction in stroke. Mice were subjected to cerebral artery occlusion (MCAO), then administered iptakalim (10 mg/kg, ip). We showed that iptakalim administration significantly promoted recovery of cerebral blood flow after cerebral ischemia and reperfusion. Furthermore, we found that iptakalim significantly inhibited pericytes contraction, decreased the number of obstructed capillaries, and improved cerebral microcirculation. Using a collagen gel contraction assay, we demonstrated that cultured pericytes subjected to oxygen-glucose deprivation (OGD) consistently contracted from 3 h till 24 h during reoxygenation, whereas iptakalim treatment (10 μM) notably restrained pericyte contraction from 6 h during reoxygenation. We further showed that iptakalim treatment promoted K-ATP channel opening via suppressing SUR2/EPAC1 complex formation. Consequently, it reduced calcium influx and ET-1 release. Taken together, our results demonstrate that iptakalim, targeted K-ATP channels, can improve microvascular disturbance by inhibiting pericyte contraction after ischemic stroke. Our work reveals that iptakalim might be developed as a promising pericyte regulator for treatment of stroke.

Expression of sphingosine‑1‑phosphate receptor 2 is correlated with migration and invasion of human colon cancer cells: A preliminary clinical study

Sphingosine-1-phosphate (S1P) is a bioactive phospholipid that serves as a potent mediator of cell proliferation, differentiation and apoptosis by binding to S1P receptors (S1PRs). S1P signalling is involved in the pathogenesis of numerous types of disease, including cancer. To the best of our knowledge, however, little is known about the expression patterns of S1PRs and their role in human colorectal cancer (CRC) cell migration and invasion. The aim of the present study was to investigate the role of S1P signalling in the metastasis of colon cancer cells and the expression of S1PRs in patients with CRC. The protein and mRNA expression levels of S1PRs and sphingosine kinases (SPHKs) in 55 patients with CRC were detected by western blotting (WB), immunohistochemical (IHC) analysis and reverse transcription-quantitative PCR. The levels of S1P in serum from patients and healthy individuals were quantified by ELISA. S1PRs antagonists JTE013, FTY720 and S1PR2-small interfering (si)RNA were used to determine the role of S1PR2 in human CRC LOVO and SW480 cell lines. Migration and invasion assays were performed for functional analysis. The levels of S1P in serum were significantly increased in patients with CRC compared with healthy individuals. The relative mRNA expression levels of S1PR2 were significantly downregulated in tumour compared with normal tissue, whereas S1PR1 and SPHK1 were upregulated. WB showed that 58% (32/55 cases) of patients presented downregulated S1PR2 protein expression. IHC analysis indicated that expression of S1PR2 was lower in tumour than in normal tissue in 65.5% (36/55 cases) of patients. Exogenous addition of S1P promoted migration and invasion in the different cell types. S1P stimulated the migration and invasion of SW480 cells. The inhibition of S1PR2 by JTE013 or S1PR2-siRNA significantly promoted the migration and invasion of SW480 cells, while FTY720 reversed these effects. The present study indicated that expression levels of S1PRs, particularly S1PR2, were associated with migration and invasion of CRC cells. The present findings revealed a novel mechanism by which S1P inhibited tumour cell migration and invasion via a S1PR2-dependent pathway, suggesting that S1PR2 may be a therapeutic target for treatment of colon cancer.

Treatment Strategies in Emergency Endoscopy for Acute Esophageal Variceal Bleeding (CHESS1905): A Nationwide Cohort Study

Background and Aims

Emergency endoscopy is recommended for patients with acute esophageal variceal bleeding (EVB) and their prognosis has improved markedly over past decades due to the increased specialization of endoscopic practice. The study aimed to compare outcomes following emergency endoscopic injection sclerotherapy (EIS) and endoscopic variceal ligation (EVL) in cirrhotic patients with acute EVB.

Methods

Cirrhotic patients with acute EVB who underwent emergency endoscopy were retrospectively enrolled from 2013 to 2020 across 34 university hospitals from 30 cities. The primary outcome was the incidence of 5-day rebleeding after emergency endoscopy. Subgroup analysis was stratified by Child-Pugh class and bleeding history. A 1:1 propensity score matching (PSM) analysis was performed.

Results

A total of 1,017 and 382 patients were included in EIS group and EVL group, respectively. The 5-day rebleeding incidence was similar between EIS group and EVL group (4% vs. 5%, P = 0.45). The result remained the same after PSM (P = 1.00). Among Child-Pugh class A, B and C patients, there were no differences in the 5-day rebleeding incidence between the two groups after PSM (P = 0.25, 0.82, and 0.21, respectively). As for the patients with or without bleeding history, the differences between EIS group and EVL group were not significant after PSM (P = 1.00 and 0.26, respectively).

Conclusion

The nationwide cohort study indicates that EIS and EVL are both efficient emergency endoscopic treatment strategies for acute EVB. EIS should not be dismissed as an economical and effective emergency endoscopic treatment strategy of acute EVB. ClincialTrials.gov number NCT04307264.

[Clinical and microbiological characteristics of hypervirulent Klebsiella pneumoniae lung abscess]

Objective: To study the clinical and microbiological characteristics of hypervirulent Klebsiella pneumoniae (hvKP) lung abscess, and to compare with the classic Klebsiella pneumoniae (cKP) lung abscess. Methods: A total of 18 patients with Klebsiella pneumoniae lung abscesses admitted to the First Affiliated Hospital of Zhejiang University School of Medicine from January 2017 to September 2020 enrolled. The strains with positive result of string test were defined as hvKP, and the negative strains were defined as cKP. The patients' basic diseases, symptoms, laboratory data and other clinical characteristics were collected. The microbiological characteristics of the strains included as following: VITEK method to determine the in vitro susceptibility of the strains to antibiotics; PCR to detect the capsular serotypes and virulence genes. The differences in clinical characteristics and microbiological characteristics of strains between hvKP group and cKP group were compared. Results: Among the 18 patients with Klebsiella pneumoniae lung abscess, 12 were hvKP infection, mainly male (10 cases), with a median age of 59.0 years; 8 cases in the hvKP group had an onset time of ≤2 weeks, and the median onset time was 10.5 days. There were significantly more diabetes (12 cases) and extrapulmonary abscesses (11 cases) in hvKP group than those in cKP group (both P<0.001). The extrapulmonary abscesses in the hvKP group were mainly liver abscesses (10 cases), and 4 cases were multi-site (≥3) abscesses. The number of indwelling catheters and invasive procedures before infection were higher in cKP group than those in hvKP group (both P=0.025). The imaging of Klebsiella pneumoniae lung abscess was mainly subpleural with the size of less than 10 cm. There were more multiple abscesses cases in hvKP group (9 cases) than cKP group (P=0.009). The median interval time between the detection of a pulmonary abscess and an extrapulmonary abscess was 1.0 day. The resistance rate of common antibiotics was significantly lower in hvKP than cKP. Conclusions: hvKP lung abscesses are more common in patients with diabetes, and the clinical manifestations are nonspecific. The lung imaging manifestations are multiple subpleural abscesses, indicating hematogenous dissemination. Liver abscesses were present in most cases, suggesting the source of infection. The main virulent gene of hypervirulent Klebsiella pneumoniae is aero. For patients with hvKP lung abscess, attention should be paid to finding hidden lesions.

[The method of determination for butyronitrile and isobutyronitrile in the air of workplace by dissolved desorption-gas chromatography]

Objective: To establish a method for the determination of butyronitrile and isobutyronitrile in the air of workplace by gas chromatography. Methods: In March 2020, butyronitrile and isobutyronitrile in the air of workplace was collected by silica gel, eluted with methanol, separated and determined by gas chromatogram with flame ionization detector, the characteristics of determination of nitrile and isobutyronitrile by gas chromatography were analyzed. Results: The limit of detection for butyronitrile and isobutyronitrile was 0.33 μg/ml. The linear range of butyronitrile determined by this method was 1.60-1600.00 μg/ml, y=2.295x-3.480, and the coefficient correlation was 0.99998, and the minimum detection concentration was 0.22 mg/m(3) (collected sample volume was 1.50 L) . The within-run precisions were 2.43%-4.12%, the between-run precisions were 1.72%-3.70%, and the desorption rates were 93.26%-98.41%. The linear range of isobutyronitrile determined by this method was 1.52-1520.00 μg/ml, y=2.208x-0.102, and the coefficient correlation was 0.99998, and the minimum detection concentration was 0.22 mg/m(3) (collected sample volume was 1.50 L) . The within-run precisions were 2.52%-3.22%, the between-run precisions were 1.20%-3.82%, and the desorption rates were 96.85%-102.50%. The sealed samples could be stored at least 10 days at room temperature without significant loss. Conclusion: The method has the advantages of good precision, high sensitivity and simple operation. It is suitable for the simultaneous determination of butyronitrile and isobutyronitrile in the air of workplace.

ZLN005 Alleviates In Vivo and In Vitro Renal Fibrosis via PGC-1α-Mediated Mitochondrial Homeostasis

Currently, chronic kidney disease (CKD) is one of the most common diseases; it is also a serious threat to human health due to its high mortality, and its treatment is still a major clinical challenge. Mitochondrial dyshomeostasis plays an important role in the development of CKD. ZLN005 is a novel peroxisome-proliferator-activated receptor-γ coactivator-1α (PGC-1α) activator from our laboratory. To explore whether ZLN005 can protect against CKD in vivo and in vitro, a unilateral ureteral obstruction (UUO) model and TGF-β1-treated renal tubular epithelial cells (TECs), respectively, were used in this study. We found that ZLN005-administrated UUO mice showed less kidney damages than control mice, as indicated by the reduced expression of fibrotic biomarkers in the kidney of UUO mice. ZLN005 treatment also alleviated the TGF-β1-induced fibrotic phenotype and lipid accumulation in TECs. Our study demonstrated ZLN005 treatment improved mitochondrial homeostasis at least partially via the activation of PGC-1α, thus maintaining mitochondria function and energy homeostasis. In summary, ZLN005 treatment ameliorates UUO-induced renal fibrosis, providing conceptional support for mitochondria-targeting therapies for chronic kidney disease.

The early diagnostic value of ankle-brachial index combined with feet electrochemical skin conductance for peripheral artery disease in type 2 diabetes

Aims/Introduction

In this paper, we focused on exploring the diagnostic and predictive clinical utility of ankle‐brachial index (ABI) in combination with feet electrochemical skin conductance (FESC) for peripheral artery disease (PAD) in Chinese patients with type 2 diabetes mellitus (T2DM).

Materials and Methods

Overall, 183 Chinese T2DM patients were enrolled in this study. The patients were classified into three groups: Group 1 comprised of uncomplicated type 2 diabetics (n = 36), Group 2 consisted of patients with diabetic peripheral neuropathy (n = 103) whereas Group 3 patients displayed peripheral artery disease (n = 44). All patients underwent Sudoscan test using a Sudoscan (Paris, France) and ABI assessment.

Results

Multivariate logistic regression models revealed that FESC was an independent risk factor of developing PAD in patients with type 2 diabetes. The AUC for diagnostic, positive predictive and negative predictive value of ABI in combination with FESC for PAD were 0.907, 0.733 and 0.920, respectively. The specificity and sensitivity of ABI in combination with FESC for PAD were 0.914 and 0.750, respectively.

Conclusions

Ankle‐brachial index in combination with FESC can accurately be used in early diagnosis of PAD.

[Effects and mechanism of estrogen receptor β agonist on the migration and oxidative stress of human umbilical vein endothelial cell under high glucose condition]

Objective: To investigate the effects and related mechanism of estrogen receptor β (ERβ) agonist on the migration and oxidative stress of human umbilial vein endothelial cells (HUVECs) under high glucose condition. Methods: The experimental research method was adopted. HUVECs were routinely cultured and passaged, and then cells of the logarithmic growth phase were collected for the subsequent experiments. The cells were divided into three groups according to the random number table, including normal control group (cultured with Roswell Park Memorial Institute 1640 cell culture medium (the same cell culture medium below) containing 5.5 mmol/L D-glucose), high glucose alone group (cultured with cell culture medium containing 25.0 mmol/L D-glucose alone), and high glucose+ERβ agonist diarylpropionitrile (DPN) group (cultured with cell culture medium containing 25.0 mmol/L D-glucose and 10 μmol/L DPN). Scratch test was conducted to detect the cell migration rate in the 3 groups at 24 h post scratching. Fluorescent probe method was used to detect the reactive oxygen species (ROS, denoted by red fluorescence intensity) of cells in the 3 groups on 5 d post culture. Western blotting was used to detect the protein expression levels of vascular endothelial growth factor (VEGF) and superoxide dismutase 2 (SOD2) of cells in the 3 groups on 5 d post culture. In the above-mentioned experiments, cells were grouped and cultured correspondingly as before, the number of samples in each group was 5. Data were statistically analyzed with one-way analysis of variance and least significant difference t test. Results: At 24 h post scratching, the cell migration rate in high glucose alone group was (36±5)%, which was significantly lower than (76±4)% of normal control group and (65±5)% of high glucose+DPN group (t=14.511, 9.603, P<0.01), and the cell migration rate in high glucose+DPN group was significantly lower than that in normal control group (t=3.943, P<0.01). On 5 d post culture, the level of ROS of cells in high glucose alone group (1.81±0.12) was significantly increased compared with normal control group and high glucose+DPN group (1.00±0.14, 0.91±0.15, t=9.679, 10.549, P<0.01), while the level of ROS of cells in normal control group and high glucose+DPN group were close (t=1.031, P>0.05). On 5 d post culture, the protein expression levels of VEGF and SOD2 of cells in high glucose alone group were significantly lower than the levels of normal control group (t=14.175, 13.787, P<0.01) and high glucose+DPN group (t=6.321, 17.750, P<0.01). The protein expression level of VEGF of cells in high glucose+DPN group was significantly lower than the level of normal control group (t=7.206, P<0.05), while the protein expression level of SOD2 of cells in high glucose+DPN group was significantly higher than the level of normal control group (t=2.890, P<0.05). Conclusions: The activation of ERβ can improve the inhibition of HUVECs migration induced by high glucose and alleviate oxidative stress injury induced by high glucose, which may be achieved by promoting the expression of VEGF and SOD2.

[Changes in the related indicators of bone formation and bone resorption in severely burned rats]

Objective: To observe the changes in the related indicators of bone formation and bone resorption in severely burned rats. Methods: The experimental research method was adopted. Thirty female Sprague-Dawley rats aged 6 to 8 weeks were divided into sham injury group, 12% total body surface area (TBSA) full-thickness burn group, and 24%TBSA full-thickness burn group according to the random number table, with 10 rats in each group. The rats were treated on the back correspondingly, after which, the burned rats were rehydrated by intraperitoneal injection according to the Parkland formula, and the wound was coated with 20 g/L iodophor until wound healing. On post injury day (PID) 28, the tibia tissue of rats in each group was collected. The new bone tissue and the number of osteoclasts were observed after staining with Masson and tartrate-resistant acid phosphatase, respectively. The abdominal aortic blood of rats in each group was harvested for serum preparation. The bone metabolism indexes of serum calcium ion and phosphorus ion concentration were determined by the methyl thymol blue colorimetric method and phosphomolybdic acid method, respectively. The serum levels of bone formation marker of aminoterminal propeptide of type 1 procollagen (P1NP) and bone resorption marker of beta-carboxy-terminated peptide of type Ⅰ collagen (β-CTX) were determined by enzyme-linked immunosorbent assay. The first lumbar spine tissue of rats in each group was collected, and the mRNA expression levels of osteoprotegerin, receptor activator of nuclear factor-κB ligand (RANKL), tumor necrosis factor receptor-associated factor 6 (TRAF-6), nuclear factor of activated T cell 1 (NFATC1), c-Fos, and c-Src were detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction. Data were statistically analyzed with one-way analysis of variance, Bonferroni method, Welch test, Games-Howell test, Kruskal-Wallis test, Mann-Whitney U test, and Bonferroni correction. Results: On PID 28, compared with that in sham injury group, the formation of new bone tissue in the tibia tissue of rats in the two burn groups was decreased, and the larger the burn area, the more obvious the decrease. The numbers of osteoclasts in the tibia tissue of rats in the two burn groups were similar, both significantly more than the number in sham injury group. On PID 28, the serum calcium ion concentration and serum level of β-CTX of rats in the three groups were similar (P>0.05). The serum phosphorus ion concentration of rats in 24%TBSA full-thickness burn group was significantly higher than that in 12%TBSA full-thickness burn group (P<0.05), and the serum phosphorus ion concentrations in the two burn groups were significantly higher than the concentration in sham injury group (P<0.01). The serum level of P1NP of rats in 24%TBSA full-thickness burn group was significantly lower than that in sham injury group (P<0.01). On PID 28, the mRNA expression levels of osteoprotegerin in the first lumbar spine tissue of rats in sham injury group, 12%TBSA full-thickness burn group, and 24%TBSA full-thickness burn group were 1.01±0.20, 1.71±0.83, and 2.24±0.51, respectively, and that in 24%TBSA full-thickness burn group was significantly higher than that in sham injury group (P<0.01). The mRNA expression level of RANKL in the first lumbar spine tissue of rats in 24%TBSA full-thickness burn group was 1.31±0.17, which was significantly higher than 1.00±0.14 in sham injury group and 0.97±0.10 in 12%TBSA full-thickness burn group (P<0.01). The mRNA expression levels of TRAF-6, NFATC1 (Z=3.141, 3.782), and c-Src in the first lumbar tissue of rats in 12%TBSA full-thickness burn group and 24%TBSA full-thickness burn group and the mRNA expression level of c-Fos in the first lumbar tissue of rats in 12%TBSA full-thickness burn group were significantly higher than those in sham injury group (P<0.05 or P<0.01). The mRNA expression levels of c-Fos and c-Src in the first lumbar spine tissue of rats in 12%TBSA full-thickness burn group were significantly higher than those in 24%TBSA full-thickness burn group (P<0.01). Conclusions: Severe burns can cause a decrease in the generation of new bone tissue, an increase in the number of osteoclasts and the serum phosphorus ion concentration, and a decrease in the serum level of P1NP in rats. The level of osteoprotegerin, RANKL, TRAF-6, NFATC1, c-Fos, and c-Src in bone tissue showed an increasing trend while the level of NFATC1, c-Fos, and c-Src showed a decreasing trend with the increase of burn area.

[Research advances on the effect of hydrogen peroxide in wound healing]

Wound healing is a highly ordered biological process involving a variety of cells, fluids, and molecules. Any obstacles in the link may cause poor wound healing and even the formation of chronic wounds. In recent years, more and more studies have reported that hydrogen peroxide plays an important role in wound healing and throughout the whole process of wound healing. This article reviews the research progress of hydrogen peroxide and literatures in the related fields to provide new ideas and clues for promoting the basic and clinical research of wound healing.

Histamine Induces Microglia Activation and the Release of Proinflammatory Mediators in Rat Brain Via H1R or H4R

Histamine is a major peripheral inflammatory mediator and a neurotransmitter in the central nervous system. We have reported that histamine induces microglia activation and releases proinflammatory factors in primary cultured microglia. Whether histamine has similar effects in vivo is unknown. In the present study, we aimed to investigate the role of histamine and its receptors in the release of inflammatory mediators and activation of microglia in rat brain. We site-directed injected histamine, histamine receptor agonists or histamine receptor antagonists in the rat lateral ventricle using stereotaxic techniques. Flow cytometry was employed to determine histamine receptor expression in rat microglia. Microglia activation was assessed by Iba1 immunohistochemistry. The levels of tumour necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β) and interleukin-10 (IL-10) were measured with commercial enzyme-linked immunosorbent assay (ELISA) kits, TNF-α, IL-1β and IL-10 mRNA expressions were determined with Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR). We found that all four types of histamine receptors were expressed in rat brain microglia. Histamine was able to induce microglia activation and subsequent production of the inflammatory factors TNF-α, IL-1β and IL-10, and these effects were partially abolished by H₁R and H₄R antagonists. However, H₂R and H₃R antagonists significantly increased production of TNF-α and IL-1β, and decreased IL-10 levels. The H₁R or H₄R agonists stimulated the production of TNF-α and IL-1β, while the H₂R or H₃R agonists increased IL-10 release. Our results demonstrate that histamine induces microglia activation and the release of both proinflammatory and anti-inflammatory factors in rat brain, thus contributing to the development of inflammation in the brain. Graphical Abstract Histamine induces microglia activation and the release of both proinflammatory (TNF-α and IL-1β) and anti-inflammatory factors (IL-10) in rat brain, thus contributing to the development of inflammation in the brain.

SphK1 functions downstream of IGF-1 to modulate IGF-1-induced EMT, migration and paclitaxel resistance of A549 cells: A preliminary in vitro study

Insulin-like growth factor-1 (IGF-1) -induced epithelial-mesenchymal transition (EMT) plays a key role in the metastasis and drug resistance of non-small cell lung cancer (NSCLC). Sphingosine kinase-1 (SphK1) is also involved in EMT of NSCLC. However, the interaction between SphK1 and IGF-1 in the EMT of NSCLC is largely unknown. To clarify this issue, we examined the involvement of SphK1 in IGF-1-induced EMT using human lung cancer cell line A549, and its paclitaxel-resistant subline. Cell viability was evaluated by cell counting kit-8 assay; Migratory ability was examined using scratch wound healing test; Protein expression levels of SphK1, vimentin, fibronectin, N-cadherin and E-cadherin were detected by western blot analysis, respectively. The results showed that, IGF-1 treatment of A549 cells stimulated the expression of SphK1, the activation of ERK and AKT, the cell migration, and the expression of EMT hallmark proteins, while inhibition of SphK1 by its specific inhibitor SKI-II suppressed all the above changes and increased the sensitivity of A549 cells to paclitaxel. Our data demonstrate that SphK1 acts as a downstream effector of IGF-1 and plays a critical role in IGF-1-induced EMT, cell migration and paclitaxel resistance of A549 cells, suggesting that SphK1 might be a potential therapeutic target for NSCLC.

GNAI1 and GNAI3 Reduce Colitis-Associated Tumorigenesis in Mice by Blocking IL6 Signaling and Down-regulating Expression of GNAI2

BACKGROUND & AIMS

Interleukin 6 (IL6) and tumor necrosis factor contribute to the development of colitis-associated cancer (CAC). We investigated these signaling pathways and the involvement of G protein subunit alpha i1 (GNAI1), GNAI2, and GNAI3 in the development of CAC in mice and humans.

METHODS

B6;129 wild-type (control) or mice with disruption of Gnai1, Gnai2, and/or Gnai3 or conditional disruption of Gnai2 in CD11c+ or epithelial cells were given dextran sulfate sodium (DSS) to induce colitis followed by azoxymethane (AOM) to induce carcinogenesis; some mice were given an antibody against IL6. Feces were collected from mice, and the compositions of microbiomes were analyzed by polymerase chain reactions. Dendritic cells (DCs) and myeloid-derived suppressor cells (MDSCs) isolated from spleen and colon tissues were analyzed by flow cytometry. We performed immunoprecipitation and immunoblot analyses of colon tumor tissues, MDSCs, and mouse embryonic fibroblasts to study the expression levels of GNAI1, GNAI2, and GNAI3 and the interactions of GNAI1 and GNAI3 with proteins in the IL6 signaling pathway. We analyzed the expression of Gnai2 messenger RNA by CD11c+ cells in the colonic lamina propria by PrimeFlow, expression of IL6 in DCs by flow cytometry, and secretion of cytokines in sera and colon tissues by enzyme-linked immunosorbent assay. We obtained colon tumor and matched nontumor tissues from 83 patients with colorectal cancer having surgery in China and 35 patients with CAC in the United States. Mouse and human colon tissues were analyzed by histology, immunoblot, immunohistochemistry, and/or RNA-sequencing analyses.

RESULTS

GNAI1 and GNAI3 (GNAI1;3) double-knockout (DKO) mice developed more severe colitis after administration of DSS and significantly more colonic tumors than control mice after administration of AOM plus DSS. Development of increased tumors in DKO mice was not associated with changes in fecal microbiomes but was associated with activation of nuclear factor (NF) κB and signal transducer and activator of transcription (STAT) 3; increased levels of GNAI2, nitric oxide synthase 2, and IL6; increased numbers of CD4+ DCs and MDSCs; and decreased numbers of CD8+ DCs. IL6 was mainly produced by CD4+/CD11b+, but not CD8+, DCs in DKO mice. Injection of DKO mice with a blocking antibody against IL6 reduced the expansion of MDSCs and the number of tumors that developed after CAC induction. Incubation of MDSCs or mouse embryonic fibroblasts with IL6 induced activation of either NF-κB by a JAK2-TRAF6-TAK1-CHUK/IKKB signaling pathway or STAT3 by JAK2. This activation resulted in expression of GNAI2, IL6 signal transducer (IL6ST, also called GP130) and nitric oxide synthase 2, and expansion of MDSCs; the expression levels of these proteins and expansion of MDSCs were further increased by the absence of GNAI1;3 in cells and mice. Conditional disruption of Gnai2 in CD11c+ cells of DKO mice prevented activation of NF-κB and STAT3 and changes in numbers of DCs and MDSCs. Colon tumor tissues from patients with CAC had reduced levels of GNAI1 and GNAI3 and increased levels of GNAI2 compared with normal tissues. Further analysis of a public human colorectal tumor DNA microarray database (GSE39582) showed that low Gani1 and Gnai3 messenger RNA expression and high Gnai2 messenger RNA expression were significantly associated with decreased relapse-free survival.

CONCLUSIONS

GNAI1;3 suppresses DSS-plus-AOM-induced colon tumor development in mice, whereas expression of GNAI2 in CD11c+ cells and IL6 in CD4+/CD11b+ DCs appears to promote these effects. Strategies to induce GNAI1;3, or block GNAI2 and IL6, might be developed for the prevention or therapy of CAC in patients.

TTTCA repeat expansion causes familial cortical myoclonic tremor with epilepsy

BACKGROUND AND PURPOSE

The aim was to investigate whether abnormal TTTTA and TTTCA repeat expansions in introns of SAMD12, TNRC6A and RAPGEF2 are involved in the pathogenesis of familial cortical myoclonic tremor with epilepsy (FCMTE).

METHODS

Five families diagnosed with FCMTE were included in the current genetic analysis. Whole-exome sequencing was performed in selected patients of each family. TTTTA and TTTCA expansions were examined by repeat-primed polymerase chain reaction. The clinical features of FCMTE were elicited as defined by the common genetic mechanism of 14 patients.

RESULTS

Abnormal TTTCA expansion was identified and co-segregated in all five FCMTE families, four inserted in SAMD12 and one in RAPGEF2. The insertion of expanded TTTCA was not found in 116 control alleles. TTTTA expansion in SAMD12 was detected in 90.9% (10/11) of patients or mutation carriers; TTTTA expansion in RAPGEF2 was not found. The onset age of myoclonic tremor was 27.4 ± 5.9 (19-37) and epilepsy usually presented around age 34. Focal and generalized seizures were witnessed with various origins recorded by electroencephalogram. Cognitive deficits were not common within the first 3 years after epilepsy onset. Emotional instability was reported by most patients. No patients showed any cerebellar deficits. Valproate added with clonazepam is effective in controlling seizures but cannot guarantee a complete remission of tremor. Repeat length showed intergenerational instability and was inversely correlated with age at onset of myoclonic tremor and epilepsy.

CONCLUSIONS

TTTCA expansion insertion is associated with FCMTE in Chinese families. The homogenous genetic mechanism allowed for a higher precision of FCMTE description.

[Research progress of hydrogen-rich saline for eye diseases]

As an antioxidant, hydrogen-rich water has been widely studied in recent years. It is mild enough neither to disturb metabolic redox reactions nor to affect signaling reactive oxygen species. Therefore, there should be no or few adverse effects of H(2). Numerous studies in biology and medicine show that hydrogen-rich water has achieved good results in nervous system, digestive system, respiratory system, heart and kidney diseases. At present, there are few studies on the treatment of eye diseases with hydrogen-rich water. This review summarizes the research progress of hydrogen-rich water for eye diseases in the domestic and foreign literatures. (Chin J Ophthalmol, 2018, 54: 631-635).

AQP4‑knockout alleviates the lipopolysaccharide‑induced inflammatory response in astrocytes via SPHK1/MAPK/AKT signaling

To date, aquaporin‑4 (AQP4) has been considered as a critical contributor to neuroinflammation, but little is known about the underlying mechanism. Previous studies have shown that a critical enzyme involved in the sphingomyelin cycle, sphingosine kinase 1 (SPHK1), is implicated in inflammatory processes and contributes to chronic neuroinflammation. The present study investigated the role of AQP4 in proinflammatory cytokine release from astrocytes, with an emphasis on the SPHK1/mitogen‑activated protein kinase (MAPK)/protein kinase B (AKT) pathway. Using primary cultures isolated from AQP4+/+ and AQP4‑/‑ embryos, the production of tumor necrosis factor‑α (TNF‑α)/interleukin‑6 (IL‑6) from astrocytes challenged by lipopolysaccharide (LPS) was compared. The results showed increased secretion of TNF‑α/IL‑6 in the two groups following LPS treatment, but a significantly lower level was observed in the AQP4‑/‑ group compared with that in the AQP4+/+ group. Although upregulation of SPHK1 was detected in the two genotypes, only a mild increase in SPHK1 was found in the AQP4‑/‑ genotype. The phosphorylation of MAPK/AKT was also confirmed to be attenuated in the AQP4‑/‑ group, suggesting decreased MAPK/AKT signaling over time in AQP4‑/‑ astrocytes. Overall, the study findings demonstrated that AQP4 deficiency alleviates proinflammatory cytokine release from astrocytes, in association with the SPHK1/MAPK/AKT pathway. This data improves our understanding of AQP4 in neuroinflammatory events, highlighting a novel profile of SPHK1 as a potential target for the treatment of CNS inflammation.

[Clinical analysis of 138 multiple primary cancers diagnosed of digestive system malignant tumor initially]

Objective: To study the clinical characteristics, strategy of treatment and prognosis of multiple primary cancers(MPC) diagnosed of digestive system malignant tumor firstly. Methods: From January, 2000 to December, 2015, the clinical, follow-up and prognostic data of 138 MPC patients diagnosed of digestive system malignant tumor firstly were retrospectively analyzed. Results: 138 cases were found in 10 580 cases with malignant tumors, and the incidence was 1.30%. There were 129 cases of duplex primary cancers, 8 cases of triple primary cancers and 1 case of quintuple primary cancers. The repetitive primary cancer was occurred in digestive system (61cases, 44.2%) most frequently, with the next in respiratory system (46 cases, 33.3%). 52.2% (72 cases) suffered second primary cancer in 2 years after first primary cancer diagnosed, and 75.4% (104 cases) in 5 years. The median overall survival in patients with all cancer lesions radically treated was 168 months, better than any other treatment (68 months, P<0.05). Conclusions: The second primary cancers of MPC cases initially diagnosed of digestive system malignant tumor most frequently occurred in the digestive system and respiratory system. More concern should be attracted in follow-up, especially in the first 5 years. The key to improve patient' prognosis was radical treatment to every primary cancer.

[Association between single nucleotide polymorphism of adenylyl cyclase 3 and essential hypertension]

OBJECTIVE

To explore the association between the tag single nucleotide polymorphism (tag SNP) of the adenylyl cyclase 3 (ADCY3) and the essential hypertension (EH).

METHODS

From April to July 2013, a total of 1 061 subjects diagnosed with EH and 1 218 control subjects were recruited from Ningbo, Zhejiang Province. Information was collected by face-to-face interview. Twelve tag SNPs were detected by ligase detection reaction technique.

RESULTS

After adjusted for age, gender, body mass index and other related factors, logistic regression analysis showed that 3 loci (rs11689546, rs7593130, rs2241759)were associated with EH. AG genotype of rs11689546 was associated with 0.494 times lower risk of EH (OR=0.494, 95%CI 0.246-0.993; compared with AA genotype). CT genotype of rs7593130 was associated with 1.596 times higher risk of EH (OR=1.596, 95%CI 1.009-2.524; compared with TT genotype), and CT/CC genotype of rs7593130 was associated with 1.627 times higher risk of EH (OR=1.627, 95%CI 1.034-2.559; compared with TT genotype). AG genotype of rs2241759 was associated with 0.669 times lower risk of EH (OR=0.669, 95%CI 0.503-0.891; compared with AA genotype), and CT/CC genotype of rs2241759 was associated with 0.687 times lower risk of EH (OR=0.687, 95%CI 0.518-0.911; compared with TT genotype).

CONCLUSION

The polymorphisms of ADCY3 are associated with lower (G allele of the rs11689546 locus and G allele of the rs2241759 locus) or higher (C allele of the rs7593130 locus) risk of essential hypertension.

Prognostic significance of X-ray cross-complementing gene 1 expression in gastric cancer

Objective

The aim of this study is to identify the prognostic significance of X-ray cross-complementing gene 1 (XRCC1) in patients with gastric cancer undergoing surgery and platinum-based adjuvant chemotherapy.

Methods

Immunohistochemistry (IHC) was used to evaluate XRCC1 protein expression profiles on surgical specimens of 612 gastric cancer patients. The relationship between XRCC1 expression and existing prognostic factors, platinum-based adjuvant chemotherapy, disease-free survival (DFS) and overall survival (OS) were analyzed.

Results

Among 612 patients staged Ⅱ/Ⅲ in our study, 182 (29.74%) were evaluated as XRCC1 IHC positive. XRCC1 expression was not significantly related to OS (P = 0.347) or DFS (P = 0.297). Compared with surgery only, platinum-based adjuvant chemotherapy significantly improved the OS (P = 0.031). And the patients with negative XRCC1 expression benefited more from platinum-based adjuvant chemotherapy (P = 0.049). Multivariate analysis demonstrated that tumor size, T category, N category, vascular or nerve invasion and platinum-based chemotherapy were good prognostic factors for OS (P < 0.05). Though XRCC1 plays an important role in DNA repair pathways, no significant relationship is found in XRCC1 expression and OS among gastric cancer in our study.

Conclusions

XRCC1 might be an alternative prognostic marker for the patients of gastric cancer after radical resection. The patients with negative XRCC1 expression can benefit more from platinum-based adjuvant chemotherapy.

Construction of recombinant adenovirus Ad-rat PLCg2-shRNA and successful suppression of PLCg2 expression in BRL-3A cells

Phospholipase Cg2 (PLCg2) induces apoptosis of immune and tumor cells; however, it remains unclear whether PLCg2 promotes hepatocyte apoptosis during liver regeneration (LR). Therefore, to establish a framework for further exploring the function of PLCg2, we generated recombinant adenoviruses carrying a template encoding short hairpin (sh)-RNA targeting PLCg2 (Ad-PLCg2-shRNA), which were used to silence the expression of PLCg2 in BRL-3A cells. First, three pairs of PLCg2-shRNAs were designed, synthesized, and cloned into a shuttle vector, pHBAd-U6-GFP, after annealing. The recombinant shuttle plasmids were co-transfected with the backbone vector pHBAd-BHG into HK293 cells to package the recombinant Ad-PLCg2-shRNAs used to infect BRL-3A cells. Infection efficiency was monitored by observing the number of GFP-positive cells under a fluorescent microscope. To determine the recombinant adenoviruses with the highest silencing efficiency, levels of PLCg2 mRNA were evaluated by qRT-PCR. DNA sequencing confirmed that the correct shRNA coding sequences were inserted into the shuttle vectors and adenoviral plasmids. The titers of three recombinant adenoviruses were at least 1 x 10(10) PFU/mL. The most effective adenoviral construct, with interference efficiency of 77%, was determined by qRT-PCR. These results show that a recombinant adenovirus, Ad-PLCg2-shRNA, was developed and was effective at silencing the rat PLCg2 gene. This construct may contribute to the study of PLCg2 in hepatocyte apoptosis during LR.

Effect of dietary energy source and level on nutrient digestibility, rumen microbial protein synthesis, and milk performance in lactating dairy cows

This study was conducted to examine the effects of dietary energy source and level on intake, digestion, rumen microbial protein synthesis, and milk production in lactating dairy cows, using corn stover as a forage source. Eight multiparous Holstein cows, 4 of which were fitted with rumen cannulas, were evaluated in a replicated 4 × 4 Latin square design, with each period lasting 21 d. The cows were randomly assigned into 4 treatment groups: low-energy (LE) ground corn (GC), LE steam-flaked corn (SFC), high-energy (HE) GC, and HE SFC. Changes to ruminal energy degradation rates were induced by feeding the cows diets of either finely ground corn or SFC as components of diets with the same total energy level. Milk yield, milk protein content and yield, and milk lactose yield all increased in response to higher levels of dietary energy, whereas contents of milk fat and lactose were unaffected. Cows fed HE diets had a higher crude microbial protein yield and total-tract apparent digestibility than those receiving LE diets. Milk yield, milk protein yield, and microbial protein yield were also higher when SFC replaced GC as the main energy source for lactating cows fed LE diets. These results suggest that an increased dietary energy level and ruminal degradation rate are beneficial to milk protein production, which we suggest is due to increased yields of microbial proteins, when cows are fed corn stover as a dietary forage source.

Effects of 5-aza-2'deoxycytidine on RECK gene expression and tumor invasion in salivary adenoid cystic carcinoma

Reversion-inducing cysteine-rich protein with kazal motifs (RECK), a novel tumor suppressor gene that negatively regulates matrix metalloproteinases (MMPs), is expressed in various normal human tissues but downregulated in several types of human tumors. The molecular mechanism for this downregulation and its biological significance in salivary adenoid cystic carcinoma (SACC) are unclear. In the present study, we investigated the effects of a DNA methyltransferase (DNMT) inhibitor, 5-aza-2′deoxycytidine (5-aza-dC), on the methylation status of the RECK gene and tumor invasion in SACC cell lines. Methylation-specific PCR (MSP), Western blot analysis, and quantitative real-time PCR were used to investigate the methylation status of the RECK gene and expression of RECK mRNA and protein in SACC cell lines. The invasive ability of SACC cells was examined by the Transwell migration assay. Promoter methylation was only found in the ACC-M cell line. Treatment of ACC-M cells with 5-aza-dC partially reversed the hypermethylation status of the RECK gene and significantly enhanced the expression of mRNA and protein, and 5-aza-dC significantly suppressed ACC-M cell invasive ability. Our findings showed that 5-aza-dC inhibited cancer cell invasion through the reversal of RECK gene hypermethylation, which might be a promising chemotherapy approach in SACC treatment.

Conjugated bile acids promote cholangiocarcinoma cell invasive growth through activation of sphingosine 1-phosphate receptor 2

Cholangiocarcinoma (CCA) is an often fatal primary malignancy of the intra- and extrahepatic biliary tract that is commonly associated with chronic cholestasis and significantly elevated levels of primary and conjugated bile acids (CBAs), which are correlated with bile duct obstruction (BDO). BDO has also recently been shown to promote CCA progression. However, whereas there is increasing evidence linking chronic cholestasis and abnormal bile acid profiles to CCA development and progression, the specific mechanisms by which bile acids may be acting to promote cholangiocarcinogenesis and invasive biliary tumor growth have not been fully established. Recent studies have shown that CBAs, but not free bile acids, stimulate CCA cell growth, and that an imbalance in the ratio of free to CBAs may play an important role in the tumorigenesis of CCA. Also, CBAs are able to activate extracellular signal-regulated kinase (ERK)1/2- and phosphatidylinositol-3-kinase/protein kinase B (AKT)-signaling pathways through sphingosine 1-phosphate receptor 2 (S1PR2) in rodent hepatocytes. In the current study, we demonstrate S1PR2 to be highly expressed in rat and human CCA cells, as well as in human CCA tissues. We further show that CBAs activate the ERK1/2- and AKT-signaling pathways and significantly stimulate CCA cell growth and invasion in vitro. Taurocholate (TCA)-mediated CCA cell proliferation, migration, and invasion were significantly inhibited by JTE-013, a chemical antagonist of S1PR2, or by lentiviral short hairpin RNA silencing of S1PR2. In a novel organotypic rat CCA coculture model, TCA was further found to significantly increase the growth of CCA cell spheroidal/"duct-like" structures, which was blocked by treatment with JTE-013.

CONCLUSION

Our collective data support the hypothesis that CBAs promote CCA cell-invasive growth through S1PR2.

Effects of dietary copper on growth, digestive, and brush border enzyme activities and antioxidant defense of hepatopancreas and intestine for young grass carp (Ctenopharyngodon idella)

To investigate the effects of dietary copper (Cu) on fish growth, digestive and absorptive enzyme activities, and antioxidant status in the hepatopancreas and intestine, young grass carp (Ctenopharyngodon idella) (282±2.8 g) were fed six diets containing 0.74 (basal diet), 2.26, 3.75, 5.25, 6.70, and 8.33 mg Cu /kg diet for 8 weeks. Results showed that percentage weight gain (PWG) and feed intake were increased with dietary Cu levels up to 3.75 mg/kg diet. In addition, the positive effects of dietary Cu at a level 3.75 or 5.25 mg/kg diet on trypsin, chymotrypsin, and lipase activities in the hepatopancreas and of Na(+), K(+)-ATPase, alkaline phosphatase, creatine kinase, and γ-glutamyl transpeptidase activities in three intestine segments produced significantly (P<0.05) better feed efficiency (FE). However, amylase activity in the hepatopancreas was decreased by dietary Cu levels up to 3.75 mg/kg diet (P<0.05). In addition, dietary Cu at 3.75 or 5.25 mg/kg diet decreased malondialdehyde and protein carbonyl content partly by significantly (P<0.05) increasing the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione-S-transferase, and glutathione content in the hepatopancreas and intestine. Collectively, dietary Cu improved growth and digestive and absorptive capacity and decreased lipid peroxidation and protein oxidation partly by enhancing antioxidant defense in the hepatopancreas and intestine. The dietary Cu requirement for PWG, plasma ceruloplasmin activity, and FE of young grass carp (282-688 g) were 4.78, 4.95, and 4.70 mg/kg diet, respectively.

Note: investigation on the influences of gripping methods on elastic modulus by a miniature tensile device and in situ verification

In this paper, by gripping the specimen on various positions, including the gripping section, stress concentration transition section, and gauge length section, theoretical analysis on the influences of gripping methods on tensile elastic modulus calculation was investigated with a group of equations. Then, an image-based displacement measurement system was implemented, and the experimental verification via in situ tensile testing was carried out to verify the feasibility of the theoretical analysis by a miniature tensile device integrated with a metallographic microscope. The stress-strain curves of 2026 aluminum alloy were also obtained by gripping the specimens on various positions to illustrate the influences of gripping methods. The influence of gripping methods on elongation measurement was also investigated. This paper showed a modular calculation method of elastic modulus for the tensile testing of typical plate specimens.

Effects of reed straw, zeolite, and superphosphate amendments on ammonia and greenhouse gas emissions from stored duck manure

Stored poultry manure can be a significant source of ammonia (NH) and greenhouse gases (GHGs), including nitrous oxide (NO), methane (CH), and carbon dioxide (CO) emissions. Amendments can be used to modify physiochemical properties of manure, thus having the potential to reduce gas emissions. Here, we lab-tested the single and combined effects of addition of reed straw, zeolite, and superphosphate on gas emissions from stored duck manure. We showed that, over a period of 46 d, cumulative NH emissions were reduced by 61 to 70% with superphosphate additions, whereas cumulative NO emissions were increased by up to 23% compared with the control treatment. Reed straw addition reduced cumulative NH, NO, and CH emissions relative to the control by 12, 27, and 47%, respectively, and zeolite addition reduced cumulative NH and NO emissions by 36 and 20%, respectively. Total GHG emissions (as CO-equivalents) were reduced by up to 27% with the additions of reed straw and/or zeolite. Our results indicate that reed straw or zeolite can be recommended as amendments to reduce GHG emissions from duck manure; however, superphosphate is more effective in reducing NH emissions.

Conjugated bile acids activate the sphingosine-1-phosphate receptor 2 in primary rodent hepatocytes

Bile acids have been shown to be important regulatory molecules for cells in the liver and gastrointestinal tract. They can activate various cell signaling pathways including extracellular regulated kinase (ERK)1/2 and protein kinase B (AKT) as well as the G-protein-coupled receptor (GPCR) membrane-type bile acid receptor (TGR5/M-BAR). Activation of the ERK1/2 and AKT signaling pathways by conjugated bile acids has been reported to be sensitive to pertussis toxin (PTX) and dominant-negative Gα(i) in primary rodent hepatocytes. However, the GPCRs responsible for activation of these pathways have not been identified. Screening GPCRs in the lipid-activated phylogenetic family (expressed in HEK293 cells) identified sphingosine-1-phosphate receptor 2 (S1P(2) ) as being activated by taurocholate (TCA). TCA, taurodeoxycholic acid (TDCA), tauroursodeoxycholic acid (TUDCA), glycocholic acid (GCA), glycodeoxycholic acid (GDCA), and S1P-induced activation of ERK1/2 and AKT were significantly inhibited by JTE-013, a S1P(2) antagonist, in primary rat hepatocytes. JTE-013 significantly inhibited hepatic ERK1/2 and AKT activation as well as short heterodimeric partner (SHP) mRNA induction by TCA in the chronic bile fistula rat. Knockdown of the expression of S1P(2) by a recombinant lentivirus encoding S1P(2) shRNA markedly inhibited the activation of ERK1/2 and AKT by TCA and S1P in rat primary hepatocytes. Primary hepatocytes prepared from S1P(2) knock out (S1P(2) (-/-) ) mice were significantly blunted in the activation of the ERK1/2 and AKT pathways by TCA. Structural modeling of the S1P receptors indicated that only S1P(2) can accommodate TCA binding. In summary, all these data support the hypothesis that conjugated bile acids activate the ERK1/2 and AKT signaling pathways primarily through S1P(2) in primary rodent hepatocytes.

The fluxes of CO2 from grazed and fenced temperate steppe during two drought years on the Inner Mongolia Plateau, China

The CO(2) flux was measured by the eddy covariance method on a temperate Leymus chinensis steppe over a period of 17 months spanning two consecutive growing seasons. The amount of precipitation was nearly normal, but it was low in the early and high in the late growing period in 2006. In the 2007 growing season, the amount of precipitation was about 45% less than the multi-year average and more evenly distributed. Comparisons were made between a moderately grazed site and a 28-year-old fenced site. The maximum instantaneous CO(2) release and uptake rates were 0.12 (May) and -0.11mg CO(2)m(-2)s(-1) (July) at the fenced site, and 0.11 and -0.16mg CO(2)m(-2)s(-1) (both in July) at the grazed site. In both growing seasons, the grazed site always had a higher daily uptake rate or lower release rate than the fenced site. The grazed site was a CO(2) sink during the growing season of 2007 and a CO(2) source in the growing season of 2006, whereas the fenced site was a CO(2) source in both seasons. Lower precipitation decreased CO(2) loss during the growing season more in the grazed site than in the fenced site, mainly because of depression of total ecosystem respiration (R(e)) in the former and stimulation in the latter. During the dormant season (from October to April), the fenced and grazed sites released 60.0 and 32.4g of C per m(2), respectively. Path analysis showed that temperature had the greatest effect on daily variation of ecosystem CO(2) exchange during the growing seasons at the two study sites. The results suggest that decrease of precipitation and/or increase of temperature will likely promote C loss from L. chinensis steppes, whether fenced or grazed, and that a grazed site is more sensitive.

Inhibition of hypoxia inducible factor 1α expression suppresses the progression of esophageal squamous cell carcinoma

Hypoxia inducible factor 1α (HIF-1α) is highly expressed and is implicated in the progression of esophageal squamous cell carcinoma. To investigate the potential mechanism by which HIF-1α contributes to the progression of esophageal squamous cell carcinoma, here we established stable esophageal carcinoma cell lines Eca-109 and TE- 13 in which HIF-1α was depleted by shRNA mediated gene silencing. In additon, we used specific inhibitor YC-1 to inhibit HIF-1α expression. Our in vitro studies demonstrated that shRNA or chemical mediated inhibition of HIF-1α led to reduced proliferation and increased apoptosis of esophageal carcinoma cells, as well as the downregulatuion of HIF-1α targets VEGF, MMP2 and BCL2. Furthermore, we employed xenograft nude mice model to validate the in vitro findings and proved that depletion of HIF-1α suppressed the tumorigenicity of esophageal carcinoma cells in vivo. In conclusion, our results provide new insight into the potential role of HIF-1α in esophageal squamous cell carcinoma and open up the possibility of inhibiting HIF-1α for targeted therapy of esophageal squamous cell carcinoma.