Comparative analysis of R2R3-MYB transcription factors in the flower of Iris laevigata identifies a novel gene regulating tobacco cold tolerance

Breeding for flower cold resistance is a priority for flower breeding research in northern China. The identification of cold resistance genes will not only provide genetic resources for cold resistance breeding, but also form a basis for the study of plant cold resistance mechanisms. Based on the flower transcriptome of Iris laevigata, 20 R2R3-MYBs were identified and comprehensive analysis, including conservative domain, phylogenetic analyses and functional distribution, were performed for R2R3-MYBs. Expression patterns of the abiotic stress genes under cold stress were detected, the upregulated gene was genetically transformed into tobacco, and the related physiological indicators of the transgenic tobacco were measured. A novel cold resistance gene, IlMYB306, was obtained. qRT-PCR indicated that IlMYB306 was dramatically induced by cold stress and was significantly upregulated in roots. The free proline content, MDA, SOD and POD activity of the transgenic tobacco improved after cold stress, and the chlorophyll content decreased slowly. In addition, overexpression of IlMYB306 improved cold resistance of the seeds. SEM results showed leaves of transgenic tobacco had obvious folds, more grooves and bulges on the lower leaf surface. Overall, we report a novel cold resistance R2R3-MYB gene, IlMYB306, in the flower of I. laevigata, which could improve tobacco cold stress tolerance by thickening the waxy layer, increasing antioxidant activity and the content of proline.

P12.04.A Exosomes from glioma associated sphere forming cells induce a transition of invasive phenotype via transfer of EMP2 and CA9

Background

Glioblastoma multiforme (GBM) mostly occurs local recurrence at normal parenchyme adjacent tumor despite of conventional treatment. Glioma stem like cells (GSC) forming intratumoral heterogeneity within the GBM acquired the microenvironmental adaptation by inter-exosomal contents exchange between heterogenic cells. In addition, GSC has an invasive potential as like human GBM. Therefore, we investigate whether exosomal proteins of GSC affect the normal tissue invasion in GBM.

Material and Methods

Exosomes were isolated by Size-Exclusion method from conditioned media and validated by Electron microscope and Immunoblot assay. Exosomal proteomics were examined with Liquid Chromatography-Mass Spectrometry (LC/MS). To produce the fluorescent exosome, bi-cistron vectors were cloned with shRNA and CD63-GFP. To identify the effect of tranfected exosome, the isolated exosomes were treated to recipient cells and examined the invasion by 3D invasion assay and mouse intracranial model.

Results

Firstly, we dichotomized two groups following tumor invasion at matrigel assay and GSC derived orthotopic mouse model. CSC2 and X01 GSCs revealed highly invasive phenotype whereas 83NS and 528NS GSCs did not. Exosome was isolated in each group and identified by CD63 expression or electron microscopy. In proteomics analysis, hypoxia, extracellular matrix organization, GTPase cycle related proteins were enriched in highly invasive cell’s exosome. Among them, we focused the carbonic anhydrase IX (CA9) and the epithelial membrane protein 2 (EMP2) on its permissive role to glioblastoma invasion respectively. CA9 and EMP2 mRNA and protein levels were verified in GSCs and their exosomes and the high expression levels were detected in CSC2 and X01 compared to the low one in 83NS and 528NS GSCs. To evaluate the effects of CA9 and EMP2 on exosome mediated invasion potential, viral bi-cistron vectors was composed with the target gene knockdown and the CD63 fluorescence was used to detect intracellular exosome transfer. Interestingly, the decreased expression of phosphorylated FAK, a key invasive marker, was observed after Lentiviral mediated CA9- and EMP2-knockdown in highly invasive CSC2. To identify whether CA9 and EMP2 proteins are the intracellular effector protein responsible for exosome mediated glioma invasion, the donor exosomes (Exo-CSC2-sh-CA9 and Exo-CSC2-EMP2, after Lentiviral transfection to CSC2s) were isolated and treated to the non invasive 528NS cells as recipient cells. In 3D invasion assay, Exo-CSC2-shCA9 or Exo-CSC2-shEMP2 mediated tumor invasion was significantly decreased at 528NS GSCs compared to Exo-CSC2-shEV. These features were found at mouse intracranial model as well.

Conclusion

Together with these, we conclude that exosome derived from GSCs induces a transition of invasive phenotype via transfer of EMP2 and CA9 proteins.

Association between acute kidney injury and long-term mortality in patients with aneurysmal subarachnoid hemorrhage: A retrospective study

Background

Though acute kidney injury (AKI) in the context of aneurysmal subarachnoid hemorrhage (aSAH) worsens short-term outcomes, its impact on long-term survival is unknown.

Aim

We aimed to evaluate the association between long-term mortality and AKI during hospitalization for aSAH.

Methods

This was a retrospective study of patients who survived >12 months after aSAH. All patients were evaluated at West China Hospital, Sichuan University, between December 2013 and June 2019. The minimum follow-up time was over 1 year. the maximum follow-up time was about 7.3 years. AKI was defined by the KDIGO (The Kidney Disease Improving Global Outcomes) guidelines, which stratifies patients into three stages of severity. The primary outcome was long-term mortality, which was analyzed with Kaplan-Meier curves and Cox proportional hazards models.

Results

During this study period, 238 (9.2%) patients had AKI among 2,592 patients with aSAH. We confirmed that AKI during care for aSAH significantly increased long-term mortality (median 4.3 years of follow-up) and that risk increased with the severity of the kidney failure, with an adjusted hazard ratio (HR) of 2.08 (95% CI 1.49–2.89) for stage 1 AKI, 2.15 (95% CI 1.05–4.43) for stage 2 AKI, and 2.66 (95% CI 1.08–6.53) for stage 3 AKI compared with patients without AKI. Among patients with an AKI episode, those with renal recovery still had increased long-term mortality (HR 1.96; 95% CI 1.40–2.74) compared with patients without AKI but had better long-term outcomes than those without renal recovery (HR 0.51, 95% CI 0.27–0.97).

Conclusions

Among 12-month survivors of aSAH, AKI during their initial hospitalization for aSAH was associated with increased long-term mortality, even for patients who had normal renal function at the time of hospital discharge. Longer, multidisciplinary post-discharge follow-up may be warranted for these patients.

Neurofilament light chain and S100B serum levels are associated with disease severity and outcome in patients with aneurysmal subarachnoid hemorrhage

Objectives

Serum neurofilament light chain (NfL) is a biomarker for neuroaxonal damage, and S100B is a blood marker for cerebral damage. In the present study, we investigated the relationship between serum NfL and S100B levels, severity, and outcomes in patients with aneurysmal subarachnoid hemorrhage (aSAH).

Methods

We prospectively recruited aSAH patients and healthy controls between January 2016 and January 2021. Clinical results included mortality and poor outcomes (modified Rankin scale score of 3-6) after 6 months. The ultrasensitive Simoa technique was used to evaluate NfL levels in the blood, and ELISA was used to detect S100B.

Results

A total of 91 patients and 25 healthy controls were included in the study, with a death rate of 15.4%. The group of aSAH patients had significantly higher serum levels of NfL and S100B (P < 0.01). Furthermore, the levels of NfL and S100B increased when the Hunt-Hess, World Federation of Neurological Surgeons (WFNS), and Fisher grades increased (P < 0.01). Serum NfL and S100B levels were linked to poor prognoses and low survival rates. The blood levels of NfL and S100B were found to be an independent predictor related to 6-month mortality in multivariable analysis. Additionally, the areas under the curves for NfL and S100B levels in serum were 0.959 and 0.912, respectively; the clinical diagnostic critical thresholds were 14.275 and 26.54 pg/ml, respectively; sensitivities were 0.947 and 0.921, and specificities were 0.849 and 0.811.

Conclusions

The NfL and S100B values for aSAH patients within 12 days of admission were considerably associated with Hunt-Hess grade, WFNS, and Fisher grade. The higher the grade, the higher the NfL and S100B value, and the poorer the prognosis. Serum NfL and S100B values could be feasible biomarkers to predict the clinical prognosis of patients with aSAH.

Strong Constraints on Neutrino Nonstandard Interactions from TeV-Scale ν_{μ} Disappearance at IceCube

We report a search for nonstandard neutrino interactions (NSI) using eight years of TeV-scale atmospheric muon neutrino data from the IceCube Neutrino Observatory. By reconstructing incident energies and zenith angles for atmospheric neutrino events, this analysis presents unified confidence intervals for the NSI parameter ε_{μτ}. The best-fit value is consistent with no NSI at a p value of 25.2%. With a 90% confidence interval of -0.0041≤ε_{μτ}≤0.0031 along the real axis and similar strength in the complex plane, this result is the strongest constraint on any NSI parameter from any oscillation channel to date.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Mutational landscape of nasopharyngeal carcinoma based on targeted next-generation sequencing: implications for predicting clinical outcomes

Background

The aim of this study was to draw a comprehensive mutational landscape of nasopharyngeal carcinoma (NPC) tumors and identify the prognostic factors for distant metastasis-free survival (DMFS).

Methods

A total of forty primary nonkeratinizing NPC patients underwent targeted next-generation sequencing of 450 cancer-relevant genes. Analysis of these sequencing and clinical data was performed comprehensively. Univariate Cox regression analysis and multivariate Lasso-Cox regression analyses were performed to identify factors that predict distant metastasis and construct a risk score model, and seventy percent of patients were randomly selected from among the samples as a validation cohort. A receiver operating characteristic (ROC) curve and Harrell’s concordance index (C-index) were used to investigate whether the risk score was superior to the TNM stage in predicting the survival of patients. The survival of patients was determined by Kaplan–Meier curves and log-rank tests.

Results

The twenty most frequently mutated genes were identified, such as KMT2D, CYLD, and TP53 et al. Their mutation frequencies of them were compared with those of the COSMIC database and cBioPortal database. N stage, tumor mutational burden (TMB), PIK3CA, and SF3B1 were identified as predictors to build the risk score model. The risk score model showed a higher AUC and C-index than the TNM stage model, regardless of the training cohort or validation cohort. Moreover, this study found that patients with tumors harboring PI3K/AKT or RAS pathway mutations have worse DMFS than their wild-type counterparts.

Conclusions

In this study, we drew a mutational landscape of NPC tumors and established a novel four predictor-based prognostic model, which had much better predictive capacity than TNM stage.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10020-022-00479-4.

[Multimodal Magnetic Resonance and Fluorescence Imaging of the Induced Pluripotent Stem Cell Transplantation in the Brain]

The understanding of the engrafted cell behaviors such as the survival, growth and distribution is the prerequisite to optimize cell therapy, and a multimodal imaging at both anatomical and molecular levels is designed to achieve this goal. We constructed a lentiviral vector carrying genes of ferritin heavy chain 1 (FTH1), near-infrared fluorescent protein (iRFP) and enhanced green fluorescent protein (egfp), and established the induced pluripotent stem cells (iPSCs) culture stably expressing these three reporter genes. These iPSCs showed green and near-infrared fluorescence as well as the iron uptake capacity in vitro. After transplanted the labeled iPSCs into the rat brain, the engrafted cells could be in vivo imaged using magnetic resonance imaging (MRI) and near-infrared fluorescent imaging (NIF) up to 60 days at the anatomical level. Moreover, these cells could be detected using EGFP immunostaining and Prussian blue stain at the cellular level. The developed approach provides a novel tool to study behaviors of the transplanted cells in a multi-modal way, which will be valuable for the effectiveness and safety evaluation of cell therapy.

[Methylation of p16 gene and reduced expression of p16 protein in insulinoma associated with clinicopathological features]

Objective: To study the alterations of p16 gene and its expression in insulinoma and to correlate the findings with clinicopathological characteristics. Methods: Expression of p16 protein was detected in 72 insulinomas and 49 para-tumoral or normal pancreatic tissues by immunohistochemical staining. Genomic DNA was isolated from 32 tumor tissue and 17 paired pancreatic tissues and bisulfite-modified. Promoter methylation status of p16 gene was detected in 32 tumor tissue and 17 paired pancreatic tissues by methylation specific PCR. The findings were correlated with the clinicopathological features. Results: There were 30 males and 42 females in all 72 patients, aged (46.5±14.0) years. Loss or reduced expression of p16 protein was found in 42 of 72 insulinomas (58.3%) while loss or reduced expression of p16 was seen in only 34.7% (17/49) of para-tumoral or normal pancreatic tissues (χ²=6.52, P=0.011). Promoter methylation of p16 gene was found in 13 of 32 insulinomas (40.6%) and only 2 of 17 (11.8%) para-tumoral tissues (χ²=4.35, P=0.037). The expression of p16 protein in insulinoma was not associated with clinicopathological features such as gender, age, tumor size and tumor grade. Conclusions: Loss or reduced expression of p16 protein was found in insulinomas, and associated with p16 gene promoter methylation.

Intestinal Dopamine Receptor D2 is Required for Neuroprotection Against 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced Dopaminergic Neurodegeneration

A wealth of evidence has suggested that gastrointestinal dysfunction is associated with the onset and progression of Parkinson's disease (PD). However, the mechanisms underlying these links remain to be defined. Here, we investigated the impact of deregulation of intestinal dopamine D2 receptor (DRD2) signaling in response to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced dopaminergic neurodegeneration. Dopamine/dopamine signaling in the mouse colon decreased with ageing. Selective ablation of Drd2, but not Drd4, in the intestinal epithelium, caused a more severe loss of dopaminergic neurons in the substantia nigra following MPTP challenge, and this was accompanied by a reduced abundance of succinate-producing Alleoprevotella in the gut microbiota. Administration of succinate markedly attenuated dopaminergic neuronal loss in MPTP-treated mice by elevating the mitochondrial membrane potential. This study suggests that intestinal epithelial DRD2 activity and succinate from the gut microbiome contribute to the maintenance of nigral DA neuron survival. These findings provide a potential strategy targeting neuroinflammation-related neurological disorders such as PD.

Exosomes derived from stem cells from the apical papilla alleviate inflammation in rat pulpitis by upregulating regulatory T cells

AIM

To evaluate the effects of exosomes derived from stem cells from the apical papilla (SCAP-Exos) in rats with experimentally induced pulpitis and the effects of SCAP-Exos on the conversion of regulatory T cells (Tregs) and methylation status of the Foxp3 locus in Tregs in vitro.

METHODOLOGY

SCAP-Exos were isolated and identified using transmission electron microscopy, western blotting, and nanoparticle tracking analysis. Lipopolysaccharide was used to experimentally induced pulpitis in rats, and the effects of SCAP-Exos on the rats with pulpitis were detected using haematoxylin-eosin staining and immunofluorescence staining. CD4+CD25- T cells were treated with different doses of SCAP-Exos, and flow cytometric analysis was used to assess the effects of SCAP-Exos on Treg proliferation and conversion. An enzyme-linked immunosorbent assay (ELISA) was used to evaluate the expression of interleukin 10 (IL-10). MethylTarget^® technology was used to measure the methylation level of the Foxp3 locus in T cells. The expression levels of ten-eleven-translocation (Tet) 1, Tet2, and Tet3 in T cells were detected by real-time PCR and western blotting.

RESULTS

SCAP-Exos had an elliptical vesicle-like structure with a diameter of approximately 143.7 nm and expressed the exosomal markers Alix and CD9. SCAP-Exo administration increased Treg accumulation in the inflamed dental pulp and alleviated inflammation in the dental pulp in vivo. SCAP-Exos promoted Treg conversion in vitro. Mechanistically, SCAP-Exos promoted Tet2-mediated Foxp3 demethylation to maintain the stable expression of Foxp3.

CONCLUSIONS

SCAP-Exos promoted Treg conversion and effectively alleviated inflammation in the dental pulp of rats. This study shows that SCAP-Exos can regulate the local immune microenvironment to favour tissue regeneration, thus providing a potential novel strategy utilising SCAP-Exos as a cell-free approach to treat early inflammation of dental pulp in immature permanent teeth in the clinic.

Stimulated Insulin Secretion Predicts Changes in Body Composition Following Weight Loss in Adults with High BMI

BACKGROUND

The aim of obesity treatment is to promote loss of fat relative to lean mass. However, body composition changes with calorie restriction differ among individuals.

OBJECTIVES

The goal of this study was to test the hypothesis that insulin secretion predicts body composition changes among young and middle-age adults with high BMI (in kg/m2) following major weight loss.

METHODS

Exploratory analyses were conducted with pre-randomization data from 2 large feeding trials: the Framingham, Boston, Bloomington, Birmingham, and Baylor study (FB4; n = 82, 43.9% women, BMI ≥27) and the Framingham State Food Study [(FS)2; n = 161, 69.6% women, BMI ≥25]. Participants in the 2 trials consumed calorie-restricted moderate-carbohydrate or very-low-carbohydrate diets to produce 12-18% weight loss in ∼14 wk or 10-14% in ∼10 wk, respectively. We determined insulin concentration 30 min after a 75-g oral glucose load (insulin-30) as a measure of insulin secretion and HOMA-IR as a measure of insulin resistance at baseline. Body composition was determined by DXA at baseline and post-weight loss. Associations were analyzed using general linear models with adjustment for covariates.

RESULTS

In FB4, higher insulin-30 was associated with a smaller decrease in fat mass (0.441 kg per 100 μIU/mL increment in baseline insulin-30; P = 0.005; -1.20-kg mean difference between the first compared with the fifth group of insulin-30) and a larger decrease in lean mass (-0.465 kg per 100 μIU/mL; P = 0.004; 1.27-kg difference). Participants with higher insulin-30 lost a smaller proportion of weight loss as fat (-3.37% per 100 μIU/mL; P = 0.003; 9.20% difference). Greater HOMA-IR was also significantly associated with adverse body composition changes. Results from (FS)2 were qualitatively similar but of a smaller magnitude.

CONCLUSIONS

Baseline insulin dynamics predict substantial individual differences in body composition following weight loss. These findings may inform understanding of the pathophysiological basis for weight regain and the design of more effective obesity treatment. Registered at clinicaltrials.gov as NCT03394664 and NCT02068885.

Multimodal Magnetic Resonance and Fluorescence Imaging of the Induced Pluripotent Stem Cell Transplantation in the Brain

Abstract

The understanding of the engrafted cell behaviors such as the survival, growth and distribution is the prerequisite to optimize cell therapy, and a multimodal imaging at both anatomical and molecular levels is designed to achieve this goal. We constructed a lentiviral vector carrying genes of ferritin heavy chain 1 (FTH1), near-infrared fluorescent protein (iRFP) and enhanced green fluorescent protein (egfp), and established the induced pluripotent stem cells (iPSCs) culture stably expressing these three reporter genes. These iPSCs showed green and near-infrared fluorescence as well as the iron uptake capacity in vitro. After transplanted the labeled iPSCs into the rat brain, the engrafted cells could be in vivo imaged using magnetic resonance imaging (MRI) and near-infrared fluorescent imaging (NIF) up to 60 days at the anatomical level. Moreover, these cells could be detected using EGFP immunostaining and Prussian blue stain at the cellular level. The developed approach provides a novel tool to study behaviors of the transplanted cells in a multimodal way, which will be valuable for the effectiveness and safety evaluation of cell therapy.

Two Heterometallic Nanoclusters [DyIII4NiII8] and [DyIII10MnIII4MnII2]: Structure, Assembly Mechanism, and Magnetic Properties

A full understanding of the assembly mechanisms of coordination complexes is of great importance for a directional synthesis under control. We thus explored here the formation mechanisms of the two new heterometallic nanoclusters [Dy^III₄Ni^II₈(μ₃-OH)₈(L)₈(OAc)₄(H₂O)₄]·3.25EtOH·4CH₃CN (1) and [Dy^III₁₀Mn^III₄Mn^II₂O₄(OH)₁₂(OAc)₁₆(L)₄(HL)₂(EtOH)₂]·2EtOH·2CH₃CN·2H₂O (2) with different cubane-based squarelike ring structures, which were obtained from the reactions of 4-bromo-2-[(2-hydroxypropylimino)methyl]phenol (H₂L) with Dy(NO)₃·6H₂O and the transition metal salt Ni(OAc)₂·4H₂O or Mn(OAc)₂·4H₂O. The high-resolution electrospray ionization mass spectrometry (HRESI-MS) tests showed that the skeletons of clusters 1 and 2 have a high stability under the measurement conditions for HRESI-MS. The intermediates formed in the reaction courses of clusters 1 and 2 were tracked using time-dependent HRESI-MS, which helped to determine the proposed hierarchical assembly mechanisms for 1 (H₂L → NiL → Ni₂L₂ → Ni₃L₄ → Ni₄L₄ → DyNi₄L₅ → Dy₂Ni₆L₆ → Dy₃Ni₆L₆ → Dy₃Ni₇L₇ → Dy₄Ni₈L₈) and 2 (H₂L → MnL → DyMnL → DyMn₂L → Dy₂Mn₂L_x → Dy₈Mn₂L₂ → Dy₁₀Mn₂L₂ → Dy₁₀Mn₆L_x and H₂L → DyL → Dy₄L₂ → Dy₆L₂ → Dy₈Mn₂L₂ → Dy₁₀Mn₂L₂ → Dy₁₀Mn₆L_x). This is one of the rare examples of investigating the assembly mechanisms of 3d-4f heterometallic clusters. Magnetic studies indicated that the title complexes both show slow magnetic relaxation behaviors and cluster 1 is a field-induced single-molecule magnet.

A high-carbohydrate diet lowers the rate of adipose tissue mitochondrial respiration

Adipocyte mitochondrial respiration may influence metabolic fuel partitioning into oxidation versus storage, with implications for whole-body energy expenditure. Although insulin has been shown to influence mitochondrial respiration, the effects of dietary macronutrient composition have not been well characterized. The aim of this exploratory study was to test the hypothesis that a high-carbohydrate diet lowers the oxygen flux of adipocyte mitochondria ex vivo. Among participants in a randomized-controlled weight-loss maintenance feeding trial, those consuming a high-carbohydrate diet (60% carbohydrate as a proportion of total energy, n = 10) had lower rates of maximal adipose tissue mitochondrial respiration than those consuming a moderate-carbohydrate diet (40%, n = 8, p = 0.039) or a low-carbohydrate diet (20%, n = 9, p = 0.005) after 10 to 15 weeks. This preliminary finding may provide a mechanism for postulated calorie-independent effects of dietary composition on energy expenditure and fat deposition, potentially through the actions of insulin on fuel partitioning.