TET2 chemically modifies tRNAs and regulates tRNA fragment levels

The ten-eleven translocation 2 (TET2) protein, which oxidizes 5-methylcytosine in DNA, can also bind RNA; however, the targets and function of TET2-RNA interactions in vivo are not fully understood. Using stringent affinity tags introduced at the Tet2 locus, we purified and sequenced TET2-crosslinked RNAs from mouse embryonic stem cells (mESCs) and found a high enrichment for tRNAs. RNA immunoprecipitation with an antibody against 5-hydroxymethylcytosine (hm5C) recovered tRNAs that overlapped with those bound to TET2 in cells. Mass spectrometry (MS) analyses revealed that TET2 is necessary and sufficient for the deposition of the hm5C modification on tRNA. Tet2 knockout in mESCs affected the levels of several small noncoding RNAs originating from TET2-bound tRNAs that were enriched by hm5C immunoprecipitation. Thus, our results suggest a new function of TET2 in promoting the conversion of 5-methylcytosine to hm5C on tRNA and regulating the processing or stability of different classes of tRNA fragments.

FKF1 F-box protein promotes flowering in part by negatively regulating DELLA protein stability under long-day photoperiod in Arabidopsis

FLAVIN-BINDING KELCH REPEAT F-BOX 1 (FKF1) encodes an F-box protein that regulates photoperiod flowering in Arabidopsis under long-day conditions (LDs). Gibberellin (GA) is also important for regulating flowering under LDs. However, how FKF1 and the GA pathway work in concert in regulating flowering is not fully understood. Here, we showed that the mutation of FKF1 could cause accumulation of DELLA proteins, which are crucial repressors in GA signaling pathway, thereby reducing plant sensitivity to GA in flowering. Both in vitro and in vivo biochemical analyses demonstrated that FKF1 directly interacted with DELLA proteins. Furthermore, we showed that FKF1 promoted ubiquitination and degradation of DELLA proteins. Analysis of genetic data revealed that FKF1 acted partially through DELLAs to regulate flowering under LDs. In addition, DELLAs exerted a negative feedback on FKF1 expression. Collectively, these findings demonstrate that FKF1 promotes flowering partially by negatively regulating DELLA protein stability under LDs, and suggesting a potential mechanism linking the FKF1 to the GA signaling DELLA proteins.

Predictive value of preprocedural albuminuria for contrast-induced nephropathy non-recovery in patients undergoing percutaneous coronary intervention

Background

The degree of renal recovery from contrast induced nephropathy (CIN) may affect long-term outcomes. Albuminuria had been generally considered to be an independent risk factor of CIN. However, the predictive value of albuminuria for CIN non-recovery in patients undergoing percutaneous coronary intervention (PCI) remains unknown.

Purpose

To evaluate the association of preprocedual albuminuria and CIN non-recovery after PCI.

Methods

From January 2012 to December 2018, 550 consecutive patients developing CIN after PCI and reassessing kidney function among 1 to 12 months were enrolled. CIN non-recovery was defined as a relative decrease of serum creatinine ≥25% or 0.5 mg/dl over baseline at 1 to 12 months in patients who developed CIN. Patients were stratified into three groups according to urinary albumin: negative group (urine dipstick negative), trace group (urine dipstick trace) and positive group (urine dipstick ≥1+).

Results

Overall, 88 (16%)patients had trace urinary albumin, 74 (13.5%) patients had positive urinary albumin and 40 (7.3%) patients developed CIN non-recovery. Patients with positive urinary albumin had significantly higher incidence of CIN non-recovery [negative (3.4%), trace (11.4%) and positive (23.0%), respectively; P<0.0001]. Multivariate analysis showed that trace and positive urinary albumin were associated with an increased risk of CIN non-recovery (trace vs. negative: OR: 2.879, P=0.022; positive vs negative: OR: 2.991, P=0.021).

Conclusion

Preprocedural albuminuria was associated CIN non-recovery in patients undergoing PCI.

Incidence of CIN non-recovery

Funding Acknowledgement

Type of funding source: None

Predictive value of plasma volume status for contrast-induced nephropathy in patients with heart failure undergoing elective percutaneous coronary intervention

 

Predictive value of plasma volume status for contrast-induced nephropathy in patients with heart failure undergoing elective percutaneous coronary intervention.

Objective

Contrast-induced nephropathy (CIN) remains a common complication of coronary procedure and increases poor outcomes, especially in patients with heart failure. Plasma volume expansion relates to worsening prognosis of heart failure. We hypothesised that calculated plasma volume status (PVS) might provide predictive utility for contrast-induced nephropathy in patients with heart failure undergoing elective percutaneous coronary intervention (PCI).

Methods

We enrolled 441 patients with heart failure undergoing PCI from 2012 to 2018. Pre-procedural PVS was calculated by comparing actual plasma volume (aPV) derived from the Hakim formula to ideal plasma volume (iPV). CIN was defined as an absolute SCr increase ≥0.5 mg/dl within 72h of contrast medium exposure. We assessed the association between PVS and risk of contrast-induced nephropathy in patients with heart failure undergoing elective PCI.

Results

In 441 patients, 28 (6.3%) patients developed CIN. The median pre-procedural PVS was −0.02 (−0.09–0.05). The best cutoff value of PVS for predicting CIN was 0.04 with 64.5% sensitivity and 75.5% specificity according to the ROC analysis (C statistic = 0.718; 95% CI: 0.674–0.760),of which predictive value is similar to NT-proBNP (C statistics 0.721 vs. 0.773, P=0.355). After adjusting for potential confounding risk factors, multivariable analysis demonstrated that PVS >0.04 (OR=3.142, 95% CI: 1.185–8.332, P<0.05) and NT-proBNP >4518pg/ml (OR=7.591, 95% CI: 2.886–19.968, P<0.05)were strong independent predictors of CIN.

Conclusion

Pre-procedural PVS is an independent risk factor for predicting CIN markedly, of which predictive value is comparable to BNP and also independent of BNP. The best cutoff point of PVS for predicting CIN was 0.04.

ROC for PVS and NT-proBNP to predict CIN

Funding Acknowledgement

Type of funding source: None

Evaluation of two classical contrast-induced nephropathy definitions for predicting long-term mortality in patients undergoing elective percutaneous coronary intervention

Background

Contrast-induced nephropathy (CIN) is a frequent complication after percutaneous coronary intervention (PCI), and is associated with poor outcome. However, the optimal definition of CIN has been debated because of its different incidence and influence on prognosis. At present, there are limited data regarding th impact of different CIN definitions on long-term mortality in patients undergoing elective PCI.

Purpose

To explore the influence of two classical CIN definitions on long-term mortality and identify which definition was more suitable for predicting long-term mortality in patients undergoing elective PCI..

Methods

We prospectively observed 5600 consenting patients undergoing PCI from January 2012 to December 2018. Two classical CIN definitions include those defined by ESUR[Contrast-media-induced nephrotoxicity (CMN)] and AKIN[contrast induced acute kidney injury (CI-AKI)]. CMN was defined as an increase in serum creatinine (SCr) ≥25% or 0.5 mg/dLabove thebaseline level within 3 days,while CI-AKI wasdefined as an increase in SCr ≥50% or 0.3 mg/dL within 48hs after contrast medium exposure.The association of CIN with long-term mortality was investigated by Cox regression analysis.Interaction analyses were performed for long-term mortality across subgroups.

Results

The incidence of CIN according to ESUR (CMN) and AKIN (CI-AKI) definition were18.3% (n=1023) and 6.1% (n=342), respectively. During a median follow-up of 2 years, after adjusting other potential risk factors, multivariable cox regression analysis revealed CIN was a risk factor for long-term mortality [hazard ratio (HR): 2.021, 95% confidence interval (CI): 1.389–2.938, P<0.0001] according to AKIN definition, but not for ESUR definition (HR: 1.344, 95% CI: 0.982–1.838, P>0.05). Further interaction analysis showed that there was a significant interaction between age >75ys and CMN for long-term mortality (P=0.042) while no such association was observed between age >75ys and CI-AKI (P=0.806).

Conclusions

CIN defined by AKIN may be more suitable for predicting long-term mortality in patients undergoing elective PCI. However, in elderly patients, CIN defined by ESUR could also be used for predicting long-term mortality.

Association Between CIN and mortality

Funding Acknowledgement

Type of funding source: None

Copy number variation in HOXB7 and HOXB8 involves in the formation of beard trait in chickens

The derived feathering phenotype beard in domestic birds is an ideal resource to investigate the genetic mechanisms controlling feather development and differentiation. In the present study, we performed a GWAS and QTL linkage analysis on the trait of beard in Beijing fatty chicken. One major QTL (1.2-1.9 Mb) was identified that could explain 34% of the phenotypic variation. The copy number variation that was copied from the region (GGA27:3 578 409-3 592 890 bp) containing homebox B7 (HOXB7) and homebox B8 (HOXB8) was validated to be only exhibited in the genome of bearded chickens. Protein-protein interaction analysis indicated that HOXB7 and HOXB8 proteins could highly interact with the HOXB family members, including HOXB4, HOXB5 and HOXB6, whose genomic locations near HOXB7 and HOXB8 suggested that they may regulate their family members to involve in the formation of the beard trait in chickens. Overall, our work provides basic data for understanding the mechanisms regulating beard development and differentiation.

A modified longitudinal incision via transoral sublabial approach for removal of the nasal vestibular cyst: a clinical observation

OBJECTIVE

The aim of this study was to investigate the clinical effect of the removal of nasal vestibular cysts through a modified longitudinal incision via a transoral sublabial approach.

METHOD

In 28 cases, a nasal vestibular cyst was removed through a modified longitudinal incision via a transoral sublabial approach. A visual analogue scale score was used to evaluate the numbness of the nasal alar and upper lip. Post-operative complications were recorded. Medical photographs were used for assessment.

RESULTS

For all patients, incisions reached clinical primary healing one week after surgery. All patients were free of post-operative haematoma, infection, oronasal fistula and malformation. In the first week and the first month after surgery, numbness of the nasal alar and upper lip was recorded in few cases. The patients were followed up for 2-57 months without recurrence.

CONCLUSION

Removal of nasal vestibular cysts via a transoral sublabial approach with a modified longitudinal incision is a minimally invasive and simple surgical method with few complications and a quick recovery.

[Pathogenicity and drug-resistance analysis of Candida glabrata in patients with oral candidiasis]

Objective: To investigate the detection rate, population features and in vitro antifungal drug susceptibility of Candida glabrata in patients with oral candidiasis. Methods: The saliva fungi culture cases and the ratio of Candida glabrata in patients with oral candidiasis were analyzed during 2014-2018. Fungal species were identified by CHROMagar Candida chromogenic medium and API 20C AUX yeast identification kit. Sixty strains with cfu≥200/ml were collected and performed the in vitro antifungal susceptibility tests by using ATB FUNGUS 3 susceptibility kit. Results: The number of patients with oral candidiasis was 12 401 and the ratio of Candida glabrata was 3.44% (427/12 401) from 2014 to 2018. The positive ratio of infection increased with age increasing.The positive rate of female aged 41 to 50 years old began to increased. Female aged more than 50 years old subgroups demonstrated the tendency towards increased positive rates with increasing age. It was found out through clinical data analyzing that the patients with oral candidiasis were the most and oral lichen planus, Sjögren's syndrome and xerostomia carrying high quantity ratios of infection. Candida glabrata had highest resistance(8.3%) to the fluconazole, 6.7% of the isolates were of non-WT phenotype to itraconazole and voriconazole, all of the isolates were of WT phenotype to amphotericin B. Conclusions: The ratio of infection in the patients with oral candidiasis increased with age increasing and the olders are susceptible to infection. Candida glabrata has a certain resistance to azoles and clinically reasonable use of antifungal drugs according to the results of drug susceptibility is very important.

[Effectiveness evaluation of health belief model-based health education intervention for patients with hypertension in community settings]

Objective: To evaluate the effectiveness of health belief model-based health education intervention in improving blood pressure control of patients with hypertension in community settings. Methods: From September 2016 to September 2017, 400 newly diagnosed patients with hypertension were recruited from 6 community healthcare centers with comparable population size and health services in the Shunyi District of Beijing. All community healthcare centers were randomly assigned to the intervention group (206 patients) and the control group (194 patients). Patients in the intervention group received 3 lectures (20-30 min for each) of health belief model-based health education. Patients in the control group received usual care. The basic characteristics, health beliefs, and health literacy were collected, and blood pressure was measured before and after the intervention, respectively. The difference-in-difference model was used to analyze the change of blood pressure and the influencing factors between two groups before and after the intervention. Results: A total of 134 patients in the intervention group and 129 patients in the control group completed the study. After adjusting for the age, gender, family income, medical insurance, chronic diseases and family history, the score of perceived barriers was increased by 1.65 (P=0.016), and perceived seriousness was decreased by 0.73 (P=0.018). The systolic blood pressure of patients was decreased by 7.37 mmHg (1 mmHg=0.133 kPa, P=0.001) and diastolic blood pressure was decreased by 4.07 mmHg (P=0.014), respectively. The β (95%CI) values were -7.37 (-11.88,-2.86) and -4.07 (-7.30, -0.84). The perceived susceptibility and self-efficacy had a significant influence on the blood pressure of patients (P<0.05). Conclusion: Health belief model-based health education intervention could significantly improve the blood pressure control of patients with hypertension in the community settings.

Abstract BS1-1: RNA Methylation in human cancer

Over 150 types of post-transcriptional RNA modifications have been identified in all kingdoms of life. We have discovered the first two RNA demethylases, FTO and ALKBH5, which catalyze oxidative demethylation of the most prevalent modifications of mammalian messenger RNA (mRNA) and other nuclear RNA, N6-methyladenosine (m6A). These findings indicate that reversible RNA modification could impact biological regulation analogous to the well-known reversible DNA and histone chemical modifications. We have also characterized proteins that selectively recognize m6A-modified mRNA and affect the translation status and lifetime of the target mRNA, as well as molecular machines that deposit the m6A methylation on mRNA. Functional studies reveal m6A methylation as a critical mechanism to synchronize groups of transcripts for coordinated metabolism, translation, and decay, allowing timely and coordinated protein synthesis and transcriptome switching during cell differentiation and development. Misregulations of these processes lead to embryo lethality and human diseases such as cancer. I will focus on our discoveries of how aberrant expressions of m6A regulators could contribute to human cancer. I will also present effects of m6A regulation on immune response related to cancer progression.

Citation Format: C He. RNA Methylation in human cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr BS1-1.

Delineation of a Human Mendelian Disorder of the DNA Demethylation Machinery: TET3 Deficiency

Germline pathogenic variants in chromatin-modifying enzymes are a common cause of pediatric developmental disorders. These enzymes catalyze reactions that regulate epigenetic inheritance via histone post-translational modifications and DNA methylation. Cytosine methylation (5-methylcytosine [5mC]) of DNA is the quintessential epigenetic mark, yet no human Mendelian disorder of DNA demethylation has yet been delineated. Here, we describe in detail a Mendelian disorder caused by the disruption of DNA demethylation. TET3 is a methylcytosine dioxygenase that initiates DNA demethylation during early zygote formation, embryogenesis, and neuronal differentiation and is intolerant to haploinsufficiency in mice and humans. We identify and characterize 11 cases of human TET3 deficiency in eight families with the common phenotypic features of intellectual disability and/or global developmental delay; hypotonia; autistic traits; movement disorders; growth abnormalities; and facial dysmorphism. Mono-allelic frameshift and nonsense variants in TET3 occur throughout the coding region. Mono-allelic and bi-allelic missense variants localize to conserved residues; all but one such variant occur within the catalytic domain, and most display hypomorphic function in an assay of catalytic activity. TET3 deficiency and other Mendelian disorders of the epigenetic machinery show substantial phenotypic overlap, including features of intellectual disability and abnormal growth, underscoring shared disease mechanisms.

Lowering the Schottky barrier height of G/WSSe van der Waals heterostructures by changing the interlayer coupling and applying external biaxial strain

Graphene-based van der Waals (vdW) heterostructures composed of two-dimensional transition metal dichalcogenides (TMDs) and graphene show great potential in the design and manufacture of field effect transistors.

Phenotype and TMT-based quantitative proteomics analysis of Brassica napus reveals new insight into chlorophyll synthesis and chloroplast structure

The conversion of light energy into chemical energy in leaves is very important for plant growth and development. During this process, chlorophylls and their derivatives are indispensable as their fundamental role in the energy absorption and transduction activities. Chlorophyll variation mutants are important materials for studying chlorophyll metabolism, chloroplast biogenesis, photosynthesis and related physiological processes. Here, a chlorophyll-reduced mutant (crm1) was isolated from ethyl methanesulfonate (EMS) mutagenized Brassica napus. Compared to wild type, crm1 showed yellow leaves, reduced chlorophyll content, fewer thylakoid stacks and retarded growth. Quantitative mass spectrometry analysis with Tandem Mass Tag (TMT) isobaric labeling showed that totally 4575 proteins were identified from the chloroplast of Brassica napus leaves, and 466 of which displayed differential accumulations between wild type and crm1. The differential abundance proteins were found to be involved in chlorophyll metabolism, photosynthesis, phagosome and proteasome. Our results suggest that the decreased abundance of chlorophyll biosynthetic enzymes, proteins involved in photosynthesis might account for the reduced chlorophyll content, impaired thylakoid structure, and reduction of plant productivity. The increased abundance of proteins involved in phagosome and proteasome pathways might allow plants to adapt the proteome to environmental conditions to ensure growth and survival due to chlorophyll reduction. BIOLOGICAL SIGNIFICANCE: Photosynthesis, which consists of light and dark reactions, is fundamental to biomass production. Chloroplast is regarded as the main site for photosynthesis. During photosynthesis, the pigment chlorophyll is essential for light harvesting and energy transfer. This work provides new insights into protein expression patterns, and enables the identification of many attractive candidates for investigation of chlorophyll biosynthesis, chloroplast structure and photosynthesis in Brassica napus. These findings may be applied to improve the photosynthetic efficiency by genetic engineering in crops.

Seroma prevention strategies in laparoscopic ventral hernia repair: a systematic review

BACKGROUND

Laparoscopic ventral hernia repair (LVHR) has been increasing in popularity over the years. Seroma formation is a common complication of LVHR. The aim of this study is to review the current evidence on seroma prevention strategies following LVHR.

METHODS

A systematic search of PubMed, Embase (1946-13 February 2019) and Medline (1946-13 February 2019) databases was conducted using terms which include "seroma", "hernia, ventral" and "laparoscopy". All studies are comparative retrospective or prospective human adult studies in peer-reviewed journals describing at least one intra-operative intervention designed to decrease the rate of seroma formation in laparoscopic ventral hernia repair.

RESULTS

The database searches identified 3762 citations, and 21 studies were included for final analysis. Five studies compared the different methods of mesh fixation, nine studies compared primary defect closure (PFC) and bridged repair, two studies compared the effect of different types of meshes, two studies looked into the use of electrical cauterization, one study compared single- site laparoscopy with conventional laparoscopy, one study looked into the use of fibrin sealant and one study compared transabdominal preperitoneal placement of mesh with conventional repair. PFC appears to be the most promising with large studies showing a low rate of seroma formation with additional benefits of decreasing wound infection and recurrence rate. Cauterisation of hernia sac and injection of fibrin sealant also show promising results but are mainly derived from small studies. Other strategies did not demonstrate benefit.

CONCLUSION

Currently, primary fascial closure appears to be the most promising strategy available to decrease seroma formation after LVHR based on the results of large studies. Other promising strategies that decrease dead space such as cauterisation of the sac and fibrin sealant injection will require further multicentre trials to confirm benefit before an increase in operative time and cost can be justified for their routine use.

[Significance of prostate central gland/total gland volume ratio combined with PSA in the diagnosis of prostate cancer patients]

Objective: To explore the significance of prostate central gland/total gland volume (PVc/PV) ratio combined with PSA in the diagnosis of PSA 4-20 ng/ml prostate cancer patients. Methods: Data of patients undergoing prostate puncture in Minghang Branch, Zhongshan Hospital from July 2015 to December 2018 were retrospectively analyzed. The anteroposterior, transverse and axial diameters of the prostate and the central prostate gland were measured by magnetic resonance imaging (MRI). The differences of tPSA, f/tPSA, PSAD and PVc/PV between the prostate cancer group and non-prostate cancer group were compared. Receiver operating characteristic (ROC) curves of prostate cancer diagnosis were plotted according to tPSA, f/tPSA, PSAD, PVc/PV alone and PVc/PV combined with tPSA, respectively, and the area under the curve (AUC) was calculated and compared using tPSA as the reference. Results: There was no significant difference in tPSA between the two groups (P>0.05). However, significant differences were observed in f/tPSA, PSAD and PVc/PV between the two groups (P<0.05). The AUC value of PVc/PV combined with tPSA, PVc/PV and PSAD was 0.901 2,0.866 7 and 0.848 1,respectively, which were statistically different from that of tPSA (P<0.05). The AUC value of f/tPSA was 0.716, which was not statistically different from that of tPSA (P>0.05). Conclusion: The PVc/PV ratio combined with tPSA can be used as an important reference index for the diagnosis of prostate cancer in PSA 4-20 ng/ml patients.