Sirt1 deficiency upregulates glutathione metabolism to prevent hepatocellular carcinoma initiation in mice

Sirtuin-1 (SIRT1) is involved in various metabolic pathways, including fatty acid synthesis and gluconeogenesis in the liver. However, its role in initiation and progression of liver cancer remains unclear. Studying Sirt1 liver-specific knockout (LKO) mice in combination with diethylnitrosamine (DEN) treatment, we demonstrated that loss of Sirt1 rendered mice resistant to DEN-induced hepatocellular carcinoma (HCC) development. RNA-seq revealed that livers from LKO mice exhibited an enrichment in glutathione metabolism eight months after DEN challenge. Sirt1 deficiency elevated the expression of glutathione-s-transferase family genes by increasing the level of Nrf2, a key regulator of glutathione metabolism. Hence, LKO livers displayed a reductive environment with an increased ratio of GSH to GSSG and an elevated GSH level. Furthermore, using CRISPR knockout techniques, we confirmed that the impairment of HCC formation in LKO mice is mainly dependent on NRF2 signaling. Meanwhile, HCC induced by DEN could be blocked by the administration of N-acetyl cysteine (NAC) when administered one month after DEN challenge. However, NAC treatment starting five months after DEN injection was not able to prevent tumor development. In conclusion, our findings indicate that a reductive environment orchestrated by glutathione metabolism at an early stage can prevent the initiation of HCC.

[Determination of Three Types of New Psychoactive Tryptamines in Blood by QuEChERS Combined with UPLC-MS/MS]

Objective To establish a method combining QuEChERS and ultra-high liquid chromatography-tandem mass spectrometry （UPLC-MS/MS） for rapid screening and testing of three types of new psychoactive tryptamines in human blood： 5-MeO-DALT, 5-MeO-MiPT and 5-MeO-DiPT. Methods The effects of the type of extractant, the type and dosage of salting-out agent, and the dosage of adsorbent on the test results of the three tryptamines were investigated. Blood samples were processed by QuEChERS method and then determined by UPLC-MS/MS. Results The linear relationships of 5-MeO-DALT, 5-MeO-MiPT and 5-MeO-DiPT in human blood were good in the range of 0.5-100, 0.5-100 and 0.2-100 ng/mL, respectively, with their coefficients higher than 0.99. The limits of detection （LODs） were 0.1-0.2 ng/mg. The recoveries ranged from 84.86% to 94.57%. Intra-day and inter-day precisions were good. Conclusion The method is simple, rapid, easy to operate and has a high recovery. It is suitable for the qualitative and quantitative study of tryptamines in blood and can provide the reference for public security organs to deal with related cases.

[Preliminary study on the etiological characteristics and clinical treatment of medication-related osteonecrosis of the jaws]

Objective: To summarize the etiological characteristics and clinical treatment effects of 17 patients with medication-related osteonecrosis of the jaw (MRONJ). Methods: The clinical data of 17 patients with MRONJ admitted to the Department of Oral and Maxillofacial Surgery, the First People's Hospital of Jinzhong, Shanxi Province, from July 2016 to December 2019 were retrospectively analyzed, including 9 males and 8 females, aged (63.6±9.6) years old (43-82 years old). Descriptive analysis of the primary disease, onset factors, site of disease, clinical manifestations, treatment methods, and treatment effects was conducted through follow-up for at least 1 year. Results: Among the primary diseases of the 17 cases, 12 were malignant tumors, and 5 were osteoporosis. There were 13 cases with a history of a trigger event (tooth extraction or unsuited removable denture). Six cases occurred in the maxilla, 10 cases occurred in the mandible, and 1 case involved both the upper and lower jaws. For the most common medication used, bisphosphonate was used in 16 cases including 5 cases with concomitant use of angiogenesis-inhibiting drugs. There was 1 case resulted from receptor activator of NF-κB ligand (RANKL) monoclonal antibody application. The duration of medication application was (10.1±3.9) months (3-18 months). All 17 cases were treated surgically. Totally 15 patients healed well after surgical treatment and the other 2 patients, who had poor soft tissue healing after surgery, healed well after a second operation. Conclusions: Tooth extraction might be a major trigger factor for the onset of MRONJ in the mandible. The disease was more possibly occured in the mandible than in the maxilla. Appropriate surgical treatment could achieve a good clinical outcome.

[Preparation of doxorubicin-loaded metallic organic nanoparticles and their effect for enhancing efficacy of high-intensity focused ultrasound therapy in tumor-bearing mice]

OBJECTIVE

To prepare metallic organic nanoparticles that produce synergistic effect in high-intensity focused ultrasound (HIFU) therapy of tumors.

OBJECTIVE

Glucose oxidase (GOD), MnO₂, ferric iron (Fe³⁺) and doxorubicin (DOX) were self-assembled by physical adsorption with previously prepared manganese dioxide (MnO₂) nanoparticles to obtain GOD-MnO₂-Fe³⁺-DOX nanoparticles (GMFD NPs). HepG2 tumor-bearing nude mouse models were given intravenous injections of normal saline or GMFD NPs followed 4 h later by HIFU at the acoustic power of 90 W with a total treatment time of 3 s. The changes of tumor gray value before and after HIFU irradiation were observed and 24 h after HIFU irradiation, coagulation necrosis in the tumor tissues was examined; the histological changes of the tumor tissues were observed with HE staining.

OBJECTIVE

We successfully prepared GMFD NPs, which had an average particle size of 131.23±0.84 nm with a surface potential of 21.87±1.72 mV. GMFD NPs, with a drug loading rate of 40.18%, was capable of releasing more than 77.2% of the loaded DOX within 4 h in acidic environment. In the tumor-bearing mouse models, HIFU irradiation following GMFD NP injection, as compared with saline injection, resulted in significantly enhanced gray value of the tumor (25.5±4.5 vs 18.7±3.9, P=0.04) and greater volume of coagulation necrosis (105.80 ± 1.21 mm³ vs 38.02 ± 0.34 mm³). The energy efficiency factor (EEF) was significantly lower in GMFD NPs group than in saline group (1.79 vs 4.97, P < 0.001).

OBJECTIVE

GMFD NPs prepared in this study can enhance tumor ablation efficacy of HIFU and release DOX for further treatment of the residual tumor tissue in mice.

Initial chest radiograph scores inform COVID-19 status, intensive care unit admission and need for mechanical ventilation

AIM

To evaluate whether portable chest radiography (CXR) scores are associated with coronavirus disease 2019 (COVID-19) status and various clinical outcomes.

MATERIALS AND METHODS

This retrospective study included 500 initial CXR from COVID-19-suspected patients. Each CXR was scored based on geographic extent and degree of opacity as indicators of disease severity. COVID-19 status and clinical outcomes including intensive care unit (ICU) admission, mechanical ventilation, mortality, length of hospitalisation, and duration on ventilator were collected. Multivariable logistic regression analysis was performed to evaluate the relationship between CXR scores and COVID-19 status, CXR scores and clinical outcomes, adjusted for code status, age, gender and co-morbidities.

RESULTS

The interclass correlation coefficients amongst raters were 0.94 and 0.90 for the extent score and opacity score, respectively. CXR scores were significantly (p < 0.01) associated with COVID-19 positivity (odd ratio [OR] = 1.49; 95% confidence interval [CI]: 1.27 - 1.75 for extent score and OR = 1.75; 95% CI: 1.42 - 2.15 for opacity score), ICU admission (OR = 1.19; 95% CI: 1.09 - 1.31 for extent score and OR = 1.26; 95% CI: 1.10 - 1.44 for opacity score), and invasive mechanical ventilation (OR = 1.22; 95% CI: 1.11 - 1.35 for geographic score and OR = 1.21; 95% CI: 1.05 - 1.38 for opacity score). CXR scores were not significantly different between survivors and non-survivors after adjusting for code status (p>0.05). CXR scores were not associated with length of hospitalisation or duration on ventilation (p>0.05).

CONCLUSIONS

Initial CXR scores have prognostic value and are associated with COVID-19 positivity, ICU admission, and mechanical ventilation.

Label-free proteomics study on Shewanella putrefaciens regulated by ε-poly-lysine treatment

AIMS

The purpose of this study was to investigate the regulatory mechanism of ε-PL on Shewanella putrefaciens.

METHODS AND RESULTS

Proteomics analysis of inhibitory effect of ε-PL against S. putrefaciens was performed by label-free quantitative assay based on high-resolution mass spectrometry (MS). Quantification of 2206 proteins was obtained with high confidence, and a total of 36 differentially expressed proteins (DEPs), with 10 and 26 proteins showing upregulation and downregulation, respectively, were identified. Upon Go functional enrichment, 11, 5 and 8 specific Go terms in biological processes, molecular functions and cellular components were identified, respectively. Six KEGG pathways, including 'ribosome', were significantly enriched. Among the ribosome pathway, there were seven DEPs and all of them were distributed on large and small subunits of ribosome.

CONCLUSIONS

The significant downregulation of proteins, large subunits of ribosomal proteins RP-L18, L30 and L27, small subunits ribosomal proteins S16 and S20, and RNA polymerase β' subunit protein rpoC were the critical action sites of ε-PL to inhibit S. putrefaciens growth.

SIGNIFICANCE AND IMPACT OF THE STUDY

Shewanella putrefaciens is one of the representative fish-spoilage bacteria regardless of fish type, and poses significant problems for the fish brewery. A better understanding of the antibacterial mechanism of ε-PL on S. putrefaciens could make important contributions to development of biological control strategies of these economically important pathogens.

Anticoagulation for mechanical aortic valve replacement: an international survey

Introduction

Mechanical valves are preferred over biologic valves in younger patients because they are more durable but require long-term anticoagulation which increases the risk of bleeding. For patients with a mechanical aortic valve, the ACCP guidelines recommend a target INR of 2.5 (range 2.0–3.0) for all patients, whereas the ACC/AHA and ESC guidelines recommend a higher target for selected patients with additional risk factors for thromboembolism (TE). Data supporting the guideline recommendations are largely historical and of low quality.

Purpose

We surveyed physicians who manage anticoagulation for patient with mechanical heart valves to determine their usual practice, perceptions regarding guideline recommendations, and interest in participating in a randomized controlled trial (RCT) comparing lower with higher INR targets in patients with a mechanical aortic valve.

Methods

A 33-question web-based survey was sent to 75 cardiologists, cardiac surgeons and thrombosis specialists at centres in Canada and internationally (western Europe, South America, and the United States) who participated in previous anticoagulation trials led by investigators at McMaster University.

Results

Of the 55 respondents (73.3% response rate), 77.8% worked in academic teaching hospitals. Respondents had been in practice for a mean of 23.6 years; 40.9% followed AHA/ACC guidelines, 34.1% followed the ACCP guidelines and 22.7% followed the ESC guidelines. In patients with a mechanical aortic valve and no additional TE risk factors, 80% of respondents targeted an INR of 2.5 (range 2.0–3.0); among patients with additional TE risk factors, 48% targeted an INR of 2.5 (range 2.0–3.0) and 44% targeted an INR of 3.0 (range 2.5–3.5). With respect to guidelines: 57.1% of respondents agreed or strongly agreed that that the evidence for the guidelines was contemporary, 53.1% agreed or strongly agreed that the evidence was derived from patients with modern bi-leaflet mechanical valves, and 57.2% of respondents agreed or strongly agreed that the evidence was not of high quality. A majority of respondents (65.9%) reported that they would accept an increase in TE risk to reduce the risk of a major bleeding event; 86.4% are willing to randomize patients with a mechanical aortic valve to a target INR of 2.0 (range 1.5–2.5) if they had no risk factors for TE and 36.4% would randomize patients to a target INR of 2.0 with additional risk factors for TE.

Conclusions

Clinicians who participated in the survey followed different guidelines and employed different INR targets for patients with a mechanical aortic valve. A majority of respondents would be willing to randomize these patients to lower INR targets.

Mechanical Aortic Valves and INR Targets

Funding Acknowledgement

Type of funding source: None

Effect Of Transtibial Prosthesis Mass On Gait Asymmetries

BACKGROUND

Individuals with transtibial amputation (TTA) typically walk with an asymmetrical gait pattern, which may predispose them to secondary complications and increase risk of fall. Gait asymmetry may be influenced by prosthesis mass.

OBJECTIVES

To explore the effects of prosthesis mass on temporal and limb loading asymmetry in people with TTA following seven days of acclimation and community use.

METHODOLOGY

Eight individuals with transtibial amputation participated. A counterbalanced repeated measures study, involving three sessions (each one week apart) was conducted, during which three load conditions were examined: no load, light load and heavy load. The light load and heavy load conditions were achieved by adding 30% and 50% of the mass difference between legs, at a proximal location on the prosthesis. Kinematic and ground reaction force data was captured while walking one week after the added mass. Symmetry indices between the prosthetic and intact side were computed for temporal (Stance and Swing time) and limb loading measures (vertical ground reaction force Peak and Impulse).

FINDINGS

Following seven days of acclimation, no significant differences were observed between the three mass conditions (no load, light load and heavy load) for temporal (Stance time: p=0.61; Swing time: p=0.13) and limb loading asymmetry (vertical ground reaction force Peak: p=0.95; vertical ground reaction force Impulse: p=0.55).

CONCLUSIONS

Prosthesis mass increase at a proximal location did not increase temporal and limb loading asymmetry during walking in individuals with TTA. Hence, mass increase subsequent to replacing proximally located prosthesis components may not increase gait asymmetry, thereby allowing more flexibility to the clinician for component selection.

[Study on the role and possible mechanism of hemeoxygenase-1/carbon monoxide system in protection of quercetin against ethanol-induced hepatocytes oxidative injury]

Objective: To study the protective effect and potential mechanism of heme oxygenase (HO-1)/carbon monoxide (CO)-mediated quercetin on alcoholic oxidative damage of primary rat hepatocytes. Methods: Primary rat hepatocytes were isolated and cultured by two-step collagenase technique. Ethanol exposed primary rat hepatocytes were simultaneously added with quercetin (100 μmol/L) and/or hemoglobin (100 μmol/L) or different doses of CO-releasing molecules (CORM-2, 5-50 μmol/L) for their combined action. After polling, LDH, AST activities and MDA and GSH levels were measured in the supernatant of cell culture. The alone or combined effects of quercetin, CORM-2, hemoglobin and zinc protoporphyrin IX exposed to ethanol were detected by the activity of CYP2E1 in liver microsomes. Statistical analysis of data was performed by analysis of variance (ANOVA) and intergroup comparison was done by SNK-test. Results: Simultaneous addition of 100 μmol/L quercetin had significantly reduced ethanol-induced AST and LDH release, and GSH consumption and MDA elevation extent. Moreover, quercetin had not only lost the hemoglobin (CO blocker) protective effect but also had further exacerbated ethanol-induced lipid peroxidation. CORM-2 had reduced ethanol-induced AST and LDH release, and GSH consumption and MDA production in liver cells, and thus had dose-dependent protective effect. Ethanol had increased significantly CYP2E1 activity. Quercetin or CORM-2 had inhibited CYP2E1 activity, while hemoglobin or protoporphyrin IX had eliminated quercetin inhibitory effect and had increased the CYP2E1 activity. Quercetin, and CYP2E1 activity was constant as compared to ethanol group when CORM-2, zinc protoporphyrin IX and ethanol were incubated with hepatocytes, but the CYP2E1 activity was significantly decreased (P < 0.05), and the differences were statistically significant. Conclusion: CO/HO-1 metabolite mediates the protective effect of quercetin on alcoholic oxidative damage of hepatocytes, which may be related to the inhibition of CYP2E1 activity.

The metabolic footprint during adipocyte commitment highlights ceramide modulation as an adequate approach for obesity treatment

BACKGROUND

Metabolic modulation is capable of maintaining cell potency, regulating niche homeostasis, or determining cell fate. However, little is known regarding the metabolic landscape during early adipogenesis or whether metabolic modulation could be a potential approach for obesity treatment.

METHODS

The metabolic footprint during adipocyte commitment was evaluated by metabolomics analysis in mouse embryonic fibroblasts (MEFs). The role of apoptosis induced by ceramide and how ceramide is regulated were evaluated by omics analysis in vitro, human database and the adipocyte-specific Sirt1 knockout mouse.

FINDINGS

The metabolic footprint showed that a complicated diversity of metabolism was enriched as early as 3 h and tended to fluctuate throughout differentiation. Subsequently, the scale of these perturbed metabolic patterns was reduced to reach a balanced state. Of high relevance is the presence of apoptosis induced by ceramide accumulation, which is associated with metabolic dynamics. Interestingly, apoptotic cells were not merely a byproduct of adipogenesis but rather promoted the release of lipid components to facilitate adipogenesis. Mechanistically, ceramide accumulation stemming from hydrolysis and the de novo pathway during early adipogenesis is regulated by Sirt1 upon epigenetic alterations of constitutive Histone H3K4 methylation and H3K9 acetylation.

INTERPRETATION

The metabolic footprint during adipocyte commitment highlights that apoptosis induced by ceramide is essential for adipogenesis, which is reversed by suppression of Sirt1. Therefore, Sirt1 may constitute a target to treat obesity or other ceramide-associated metabolic syndromes.

FUNDING

This project was supported by grants from the University of Macau (SRG2015-00008-FHS, MYRG2016-00054-FHS and MYRG2017-00096-FHS to RHW; CPG2019-00019-FHS to CXD) and from the National Natural Science Foundation of China (81672603 and 81401978) to QC.

The most useful cranial ultrasound predictor of neurodevelopmental outcome at 2 years for preterm infants

AIM

To determine the most important cranial ultrasound predictors of abnormality associated with neurodevelopmental outcome at 2 years of age in preterm infants.

MATERIALS AND METHODS

A total of 343 preterm infants born between 2005 and 2010 and cared for in KK Women's and Children's Hospital, a tertiary paediatric hospital, with birth weight ≤1,250 g were assessed in this retrospective study. Serial cranial ultrasound examinations were examined for intraventricular haemorrhage and cystic periventricular leukomalacia. Ventricular-brain ratio on term equivalent cranial ultrasound was measured. Neurodevelopmental outcome was assessed by the performance on Bayley Scales of Infant and Toddler Development, 3^rd edition (Bayley-III) at 2 years corrected age. Mental delay was defined as having a combined Bayley-III score (the average of cognitive and language scores) <80.

RESULTS

The mean cognitive, language, and motor scores on Bayley-III in this cohort were 93±15, 83±18, and 92±15, respectively. Twenty-six percent of the preterm infants had mental delay and 4% had cerebral palsy. Ventricular-brain ratio >0.35 was the most significant factor associated with mental delay (odds ratio 5.28, 95% CI: 1.49-18.71, p=0.01). Other significant risk factors for mental delay were male gender, postnatal steroids, and necrotising enterocolitis, whereas maternal tertiary education was a protective factor against adverse outcome.

CONCLUSION

Ventricular-brain ratio >0.35 on term-equivalent cranial ultrasound in preterm infants is the strongest predictor for mental delay on Bayley score at 2 years of age.

Abstract P2-01-09: ESR1 mutations drive breast cancer metastasis by context-dependent alterations in adhesive and migratory properties

Background: Estrogen receptor alpha (ERα/ESR1) is mutated in 30-40% of endocrine resistant ER+ breast cancer. These mutations, primarily located in the ligand binding domain, are associated with worse outcome in patients, and preclinical studies have shown that they cause ligand independent growth. An open question is whether these mutations contribute to actual metastatic process, or merely endocrine resistance.

Methods: Using Y537S and D538G genome-edited MCF7 and T47D cells, 3D growth was assessed in ultralow attachment plates. Cell-cell adhesion was determined using calcein-labelled adhesion assay and quantitative microfluidic fluorescence microscope (qMFM). Collagen-based adhesion and spheroid invasion assays were used to test adhesive and invasive properties. Wound scratching, spheroid collective migration and Boyden chamber transwell assays were applied to monitor cell migratory phenotypes. Mutated ER cistromes were profiled using ChIP-sequencing. ESR1 mutations in clinical samples were characterized using ddPCR.

Results: Visual inspection of cells grown in suspension culture revealed more compressed multicellular spheroids in ESR1 mutant cells, indicative of increased cell-cell interactions. This observation was confirmed in both static and microfluidic conditions. This effect was more pronounced in MCF7 than T47D cells, correlating with increased expression of desmosome and gap junction genes. Pharmacological blockade of gap junctions decreased cell-cell adhesion. Decreased attachment and increased invasion to collagen were discerned in all mutant cell types. Further functional analysis identified alterations in the TIMP3-MMP axis causing these phenotypes. The cell-cell adhesion phenotypes were restricted to MCF7-Y537S/D538G and T47D-Y537S, whereas T47D-D538G cells showed significantly increased migration. A GSEA screen identified Wnt signaling as uniquely induced in this context, and combination treatment using the Wnt inhibitor LGK974 and Fulvestrant led to synergistic inhibition of migration. ChIP-seq identified mutation-specific cistromes with an overall increased ligand-independent ER binding. However, it did not reveal binding sites in any candidate metastases genes, suggesting secondary epigenetic mechanisms. The motif analysis revealed the enrichment of FOXA1 motifs in mutated ER cistromes except T47D-D538G cells. However, knockdown of FOXA1 induced significantly higher inhibition of T47D-D538G migration than Fulvestrant treatment alone, indicating a FOXA1-dominated mechanism. Collectively, these data show that ESR1 mutant cells gain metastatic properties, in addition to endocrine resistance. To prove this using clinical samples, we measured ESR1 mutations in a well-defined cohort of endocrine resistant local or distant recurrence. Significant enrichment of ESR1 mutations in distant (9/55) vs local (0/27) recurrences confirms critical role of mutant ERα in metastases.

Conclusion: Further analysis of context dependent changes in cell-cell adhesion and migration of ESR1 mutant cells might guide the design and development of drugs targeting ERα-mutant tumors, such as inhibitors of gap junction, FOXA1, MMP, and Wnt signaling pathways.

Disclosure: The authors declare no conflict of interest.

Citation Format: Li Z, Bahreini A, Levine KM, Wang P, Tasdemir N, Montanez MA, Sundd P, Wallace CT, Watkins SC, Chu D, Park BH, Hou W, Mooring MS, Zhu L, Tseng GC, Carroll JS, Atkinson JM, Lee AV, Oesterreich S. ESR1 mutations drive breast cancer metastasis by context-dependent alterations in adhesive and migratory properties [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-01-09.

[A multicenter, large-sample, randomized clinical trial on improving the median survival time of advanced non-small cell lung cancer by combination of Ginseng Rg3 and chemotherapy]

Objective: To observe the efficacy of the combination of chemotherapy and Ginseng Rg3 on advanced non-small cell lung cancer(NSCLC). Methods: In the multi-center, large-sample, randomized, double blind trial, 414 patients with Ⅲ-Ⅳ NSCLC were enrolled.199 were in the experimental group and 215 the control group. The patients in the experimental group were treated with the standard first-line chemotherapy combined with Ginseng Rg3. The patients in the control group were treated with the same chemotherapy combined with placebo. Median overall survival (OS), Karnofsky performance scale (KPS), Traditional Chinese Medicine (TCM) symptoms score and side effects of two groups were observed as main indexes. Results: The median OS were 12.03 months in the experimental group, which was significantly better than that in the control group (8.46 months, P<0.05). Hemoglobin and white blood cells were decreased after the first and second cycle of treatment in both groups. Both adverse events were significantly milder in the treatment group (P<0.05). In addition, after two courses of treatment, the KPS of patients was 78.95±9.14 in the experimental group and 76.77±9.15 in the control group, while the TCM symptoms score was 2.45±1.73 in the experimental group and 2.92±2.06 in the control group, with significant difference (P<0.05). Conclusions: Combination of TCM with Western medicine such as chemotherapy could prolong the survival of patients with advanced NSCLC. The combined therapy improved patients' symptoms and reduced chemotherapy induced myelosuppression.