Notch signaling regulates Th17 cells differentiation through PI3K/AKT/mTORC1 pathway and involves in the thyroid injury of autoimmune thyroiditis

PURPOSE

Autoimmune Thyroiditis (AIT) is the most common thyroid disease; however, there were no measures to prevent the progression of the disease. The present study attempts to identify that Notch signaling regulates the differentiation of T helper 17 (Th17) cells by activating downstream Phosphatidylinositol-3 kinase/protein kinase/mechanistic target of rapamycin complex 1 (PI3K/AKT/mTORC1) pathway participating in the thyroid injury of the experimental autoimmune thyroiditis (EAT).

METHODS

In vivo experiments, mice were randomly divided into 4 groups: a control group, an EAT group, and two groups with LY294002 treatment (pTg plus 25 mg/kg or 50 mg/kg LY294002, respectively). The degrees of thyroiditis were evaluated, and the percentage of Th17 cells, expression of interleukin-17A (IL-17A), and the main components of the Notch-PI3K signaling pathway were detected in different groups. In vitro experiments, two different dosages of LY294002 (25 and 50 μM) were used to intervene splenic mononuclear cells (SMCs) from EAT mice to further evaluate the regulatory effect of Notch-PI3K pathway on Th17 cells.

RESULTS

Our data demonstrate that the infiltration of Th17 cells and the expressions of IL-17A, Notch, hairy and split 1 (Hes1), p‑AKT (Ser473), p‑AKT (Thr308), p‑mTOR (Ser2448), S6K1, and S6K2 increased remarkably in EAT mice. After PI3K pathway was blocked, the degrees of thyroiditis were significantly alleviated, and the proportion of Th17 cells, the expression of IL-17A, and the above Notch-PI3K pathway-related molecules decreased in a dose-dependent manner. Additionally, the proportion of Th17 cells was positively correlated with the concentration of serum thyroglobulin antibody (TgAb), IL-17A, and Notch-PI3K pathway-related molecules mRNA levels.

CONCLUSIONS

Notch signal promotes the secretion of IL-17A from Th17 cells by regulating the downstream PI3K/AKT/mTORC1 pathway through Hes-Phosphatase and tensin homolog (PTEN) and participates in thyroid autoimmune damage, and the PI3K pathway inhibitor may play important effects on AIT by affecting Th17 cells differentiation.

Composite dietary antioxidant index is associated with renal anemia: a cross-sectional study

An increasing evidence suggested that chronic kidney disease (CKD) is closely related to oxidative stress, and dietary antioxidant intake can serve as a primary preventive measure for CKD. However, the relationship between composite dietary antioxidant index (CDAI) and renal anemia is not well understood. We postulated that elevated CDAI levels would be inversely related to a higher likelihood of renal anemia. The standardized calculation of CDAI was performed to investigate the relationship between them by a binary regression model. A non-linear relationship was examined through restricted cubic spline curves, and then pinpointed the inflection point. Subgroup analysis was then used to assess the robustness of the model. Finally 5880 participants were included in the study and a notable correlation between CDAI and renal anemia was found (P < 0.0001). In the multivariate linear regression model with adjustment for all confounding variables, the odds ratio (OR) and 95% confidence interval (CI) was 0.96 (0.94, 0.98; P < 0.0001), A non-linear relationship between CDAI and renal anemia was explored through restricted cubic splines, with a inflection at 6.005. Before the inflection point, for each unit rise in CDAI, the prevalence of renal anemia decreased by 5.7%. Subgroup analysis showed no statistically significant differences in interactions between any subgroups (P > 0.05). Our findings indicated a non-linear negative correlation between CDAI and renal anemia. The causal relationship still needs to be further clarified through large-scale prospective studies.

[Zinc finger protein-36 deficiency inhibits osteogenic differentiation of mouse bone marrow-derived mesenchymal stem cells and preosteoblasts by activating the ERK/MAPK pathway]

OBJECTIVE

To explore the role of zinc finger protein 36(ZFP36) in regulating osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) and preosteoblasts.

METHODS

ZFP36 expression was observed in primary mouse BMSCs and mouse preosteoblasts (MC3T3-E1 cells) during induced osteogenic differentiation. Zfp36-deficient cell models were constructed in the two cells using RNA interference technique and the changes in differentiation capacities of the transfected cells into osteoblasts were observed. Transcriptome sequencing was used to investigate the potential mechanisms of ZFP36 for regulating osteoblast differentiation of the two cells. U0126, a ERK/MAPK signal suppressor, was used to verify the regulatory mechanism of Zfp36 in osteogenic differentiation of Zfp36-deficient cells.

RESULTS

During the 14-day induction of osteogenic differentiation, both mouse BMSCs and MC3T3-E1 cells exhibited increased expression of ZFP36, and its mRNA expression reached the peak level on Day 7(P < 0.0001). The Zfp36-deficient cell models showed reduced intensity of alkaline phosphatase (ALP) staining and alizarin red staining with significantly lowered expressions of the osteogenic marker genes including Alpl, Sp7, Bglap and Ibsp (P < 0.01). Transcriptome sequencing verified the reduction of bone mineralization-related gene expressions in Zfp36-deficient cells and indicated the involvement of ERK signaling in the potential regulatory mechanism of Zfp36. Immunoblotting showed that pERK protein expression increased significantly in Zfp36-deficient cells compared with the control cells. In Zfp36-deficient MC3T3-E1 cells, inhibition of activated ERK/MAPK signaling with U0126 resulted in obviously enhanced ALP staining and significantly increased expressions of osteoblast differentiation markers Runx2 and Bglap (P < 0.05).

CONCLUSIONS

ZFP36 is involved in the regulation of osteoblast differentiation of mouse BMSCs and preosteoblasts, and ZFP36 deficiency causes inhibition of osteoblast differentiation of the cells by activating the ERK/MAPK signaling pathway.

Comparative analysis of roxadustat efficacy between maintenance hemodialysis and peritoneal dialysis patients

BACKGROUND

This study evaluated the comparative efficacy of roxadustat for renal anemia between patients on maintenance hemodialysis (HD) and peritoneal dialysis (PD).

MATERIALS AND METHODS

93 maintenance dialysis patients who regularly followed up from August 2015 to June 2021 were enrolled. Despite receiving a therapeutic dose ≥ 12,000 U/week of erythropoiesis-stimulating agents (E+SA) in the past 12 weeks, this had not worked very well. Subjects were assigned to the HD group (n = 60) or the PD group (n = 33) based on their dialysis treatment modality. All patients received oral roxadustat and were followed up for 24 weeks, after which their hemoglobin, serum iron, transferrin saturation, and ferritin were tested.

RESULTS

We observed that the hemoglobin level of PD patients was significantly increased from 76.1 ± 15.7 g/L to 106 ± 23.8 g/L (p < 0 .001), while it significantly increased from 73.8 ± 12.9 g/L to 100.7 ± 20.2 g/L (p < 0.001) in the HD patients. After 1 and 3 months of roxadustat treatment, the hemoglobin level and its change in the PD group was significantly higher compared to that in the HD group despite the higher dose of roxadustat in the latter group. In addition, roxadustat was noted to reduce cholesterol levels and stabilize serum iron levels in parallel with improving hemoglobin levels.

CONCLUSION

Roxadustat can effectively increase the hemoglobin level of maintenance dialysis patients, even in those with low erythropoietin response or erythropoietin resistance, and, more importantly, its efficacy in PD patients was more significant.

Andrographolide loaded montmorillonite attenuated enterotoxigenic Escherichia coli induced intestinal barrier injury and inflammation in a mouse model

Montmorillonite (MMT), a natural absorbent agent, has widely been accepted for its antidiarrhea function in human and farm animals; however, its specific physicochemical property limits its biological function in practical use. In the current study, raw MMT was loaded by andrographolide, namely andrographolide loaded montmorillonite (AGP-MMT). The microstructure of AGP-MMT was observed by scanning electron microscope (SEM) and X-ray diffraction (XRD). The effect of AGP-MMT on the growth performance, intestinal barrier and inflammation was investigated in an enterotoxigenic Escherichia coli (ETEC) challenged mice model. The results show that the microstructure of MMT was obviously changed after andrographolide modification: AGP-MMT exhibited a large number of spheroid particles, and floccule aggregates, but lower interplanar spacing compared with MMT. ETEC infection induced body weight losses and intestinal barrier function injury, as indicated by a lower villus height and ratio of villus height/crypt depth, whereas the serum levels of diamine oxidase (DAO), D-xylose and ETEC shedding were higher in the ETEC group compared with the CON group. Mice pretreated with AGP-MMT showed alleviated body weight losses and the intestinal barrier function injury induced by ETEC challenge. The villus height and the ratio of villus height/crypt depth, were higher in mice pretreated with AGP-MMT than those pretreated with equal levels of MMT. Pretreatment with AGP-MMT also alleviated the increased concentration of serum tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), and the corresponding genes in the jejunum induced by ETEC infection in mice. The protein and mRNA levels of IL-1β were lower in mice pretreated with AGP-MMT than those with equal levels of MMT. The results indicate that AGP-MMT was more effective in alleviating intestinal barrier injury and inflammation in mice with ETEC challenge than MMT.

Energetic Electron Precipitation Driven by Electromagnetic Ion Cyclotron Waves from ELFIN's Low Altitude Perspective

We review comprehensive observations of electromagnetic ion cyclotron (EMIC) wave-driven energetic electron precipitation using data collected by the energetic electron detector on the Electron Losses and Fields InvestigatioN (ELFIN) mission, two polar-orbiting low-altitude spinning CubeSats, measuring 50-5000 keV electrons with good pitch-angle and energy resolution. EMIC wave-driven precipitation exhibits a distinct signature in energy-spectrograms of the precipitating-to-trapped flux ratio: peaks at >0.5 MeV which are abrupt (bursty) (lasting ∼17 s, or Δ L ∼ 0.56 ) with significant substructure (occasionally down to sub-second timescale). We attribute the bursty nature of the precipitation to the spatial extent and structuredness of the wave field at the equator. Multiple ELFIN passes over the same MLT sector allow us to study the spatial and temporal evolution of the EMIC wave - electron interaction region. Case studies employing conjugate ground-based or equatorial observations of the EMIC waves reveal that the energy of moderate and strong precipitation at ELFIN approximately agrees with theoretical expectations for cyclotron resonant interactions in a cold plasma. Using multiple years of ELFIN data uniformly distributed in local time, we assemble a statistical database of ∼50 events of strong EMIC wave-driven precipitation. Most reside at L ∼ 5 - 7 at dusk, while a smaller subset exists at L ∼ 8 - 12 at post-midnight. The energies of the peak-precipitation ratio and of the half-peak precipitation ratio (our proxy for the minimum resonance energy) exhibit an L -shell dependence in good agreement with theoretical estimates based on prior statistical observations of EMIC wave power spectra. The precipitation ratio's spectral shape for the most intense events has an exponential falloff away from the peak (i.e., on either side of ∼ 1.45 MeV). It too agrees well with quasi-linear diffusion theory based on prior statistics of wave spectra. It should be noted though that this diffusive treatment likely includes effects from nonlinear resonant interactions (especially at high energies) and nonresonant effects from sharp wave packet edges (at low energies). Sub-MeV electron precipitation observed concurrently with strong EMIC wave-driven >1 MeV precipitation has a spectral shape that is consistent with efficient pitch-angle scattering down to ∼ 200-300 keV by much less intense higher frequency EMIC waves at dusk (where such waves are most frequent). At ∼100 keV, whistler-mode chorus may be implicated in concurrent precipitation. These results confirm the critical role of EMIC waves in driving relativistic electron losses. Nonlinear effects may abound and require further investigation.

[Comparative analysis of clinical diagnosis application of two intrauterine adhesion scoring criteria]

Objective: To explore the similarities and differences of China Society of Gynecology Endoscopy (CSGE) and American Fertility Society (AFS) intrauterine adhesion (IUA) scoring criteria on IUA grading and their predictive value of reproductive prognosis. Methods: From January 2016 to January 2019, a total of 1 249 patients were diagnosed with IUA by hysteroscopy at Beijing Obstetrics and Gynecology Hospital. Totally, 378 patients with complete clinical data were enrolled, and the results diagnosed by CSGT and AFS scoring criteria were compared and analyzed.And follow-up for 2 years, the pregnancy rate and live birth rate were statistical analysis. Results: (1) The grade of IUA according to AFS and CSGE scoring criteria was less consistent (κ=0.295, P<0.001). Compared with AFS, the proportion of severe IUA cases diagnosed by CSGE was significantly lower [45.8% (173/378) vs 15.1% (57/378); RR=0.22, 95%CI: 0.15-0.30, P<0.01); the proportions of both mild and moderate IUA cases were significantly higher (RR=4.16, 95%CI: 2.38-7.14; RR=2.38, 95%CI: 1.75-3.23; both P<0.01). (2) The pregnancy rates of mild, moderate and severe IUA diagnosed according to CSGE were 11/13, 64.5% (147/228), 31.8% (7/22), live birth rates were 11/13, 54.8% (125/228) and 22.7% (5/22), respectively; there were statistically significant differences between the groups (all P<0.01). The pregnancy rates of mild, moderate and severe IUA diagnosed based on AFS were 3/3, 66.9% (97/145) and 56.5% (65/115), respectively, with no statistically significant difference between the groups (P>0.05). (3) IUA grades based on both CSGE and AFS criteria were significantly negatively correlated with pregnancy rates and live birth rates (CSGE: r=-0.210, r=-0.226; AFS: r=-0.130, r=-0.147; all P<0.05). Univariate logistic regression analysis showed that CSGE had higher OR for both pregnancy rates and live birth rates compared to AFS (3.889 vs 1.657, 3.983 vs 1.554, respectrvely). Conclusions: Compared with AFS, the IUA grade based on CSGE is better related with reproductive prognosis, suggesting that the CSGE standard might be more objective and comprehensive and has better predictive value for reproductive prognosis, thus avoiding overdiagnosis and overtreatment.

[The prevalence and influence factors of work-related musculoskeletal disorders of dental nurse]

Objective: To investigate the prevalence and Influence factors of work-related musculoskeletal disorders (WMSDs) among dental nurses in tertiary stomatology hospitals. Methods: From June to July 2020, 1321 dental nurses from 18 tertiary stomatology hospitals in 18 provinces of China were enrolled as research subjects through a phased sampling method. The cross-sectional study was performed with validated instruments including the basic information questionnaire, Effort-Reward Imbalance Questionnaire, Nurse-Physician Collaboration Scale, and Chinese Musculoskeletal Questionnaire, so as to get the information about the social demography information, nursing-physician cooperation, work stress and the incidence of WMSDs. The influenang factors of WMSDs was analyzed. Results: The past prevalence, annual prevalence, and weekly prevalence of WMSDs were 80.8% (1067/1321) , 68.7% and 43.7% (575/1321) . 58.4% (771/1321) of nurses had WMSDs in three or more body parts. Neck (51.4%) , waist (42.2%) and shoulder (41.6%) were the top three body regions in the past year. The absenteeism rate due to musculoskeletal disorders ranged from 3.5% to 9.0%, waist (8.9%) and neck (8.0%) were the top two body regions. Working more than 40 hours per week (OR=1.74, P<0.001) and effect/reward>1 (OR=1.50, P=0.002) were risk factors of WMSDs (OR=1.74, 95% CI: 1.32~2.30; OR=1.50, 95%CI: 1.17~1.92, P<0.05) , while regular physical exercise every week (≥30 min per times) was the protective factor (OR=0.74, 95%CI: 0.56~0.97, P=0.030) . Conclusion: The prevalence rate of WMSDs of dental nurses in China was high, and most of the nurses suffered with many body parts. Thus, we should reduce controllable occupational stresso, ensuring adequate rest and strengthening physical exercise to reduce the incidence of WMSDs.

Genistein improves mitochondrial function and inflammatory in rats with diabetic nephropathy via inhibiting MAPK/NF-κB pathway

Purpose:

To investigate the effect of genistein on inflammation and mitochondrial function of diabetic nephropathy.

Methods:

Diabetic nephropathy model was established in Sprague-Dawley rats. Automatic biochemical analyzer was employed to detect the kidney function index, serum creatinine, serum urea nitrogen, and 24 h-urine protein and blood glucose. Hematoxylin and eosin staining and periodic acid Schiff staining were used to observe renal morphology. Mitochondrial changes and podocyte integrity were monitored by transmission electron microscope. The expression levels of mfn2, NOX4, P53, MAPK, and NF-κB were detected by Western blotting. The changes of mitochondrial membrane potential were measured by JC-1. The level of mfn2 was assessed by immunofluorescence assay.

Results:

Genistein ameliorated the kidney function with reduced Scr and blood glucose. The expressions of NOX4, MAPK, p65 and p53 were downregulated, while the expression of mnf2 was the opposite in genistein-treated kidneys. Further investigations revealed that genistein reduced expansion of mesangial matrix and oxidative stress, protected podocyte integrity and increased mitochondrial membrane potential.

Conclusions:

Genistein could alleviate diabetic nephropathy through inhibiting MAPK/NF-κB pathway, improving mitochondrial function and anti-inflammatory.

Acceleration of Brain Susceptibility-Weighted Imaging with Compressed Sensitivity Encoding: A Prospective Multicenter Study

BACKGROUND AND PURPOSE

While three-dimensional susceptibility-weighted imaging has been widely suggested for intracranial vessel imaging, hemorrhage detection, and other neuro-diseases, its relatively long scan time has necessitated the clinical verification of recent progresses of fast imaging techniques. Our aim was to evaluate the effectiveness of brain SWI accelerated by compressed sensitivity encoding to identify the optimal acceleration factors for clinical practice.

MATERIALS AND METHODS

Ninety-nine subjects, prospectively enrolled from 5 centers, underwent 8 brain SWI sequences: 5 different folds of compressed sensitivity encoding acceleration (CS2, CS4, CS6, CS8, and CS10), 2 different folds of sensitivity encoding acceleration (SF2 and SF4), and 1 without acceleration. Images were assessed quantitatively on both the SNR of the red nucleus and its contrast ratio to the CSF and, subjectively, with scoring on overall image quality; visibility of the substantia nigra-red nucleus, basilar artery, and internal cerebral vein; and diagnostic confidence of the cerebral microbleeds and other intracranial diseases.

RESULTS

Compressed sensitivity encoding showed a promising ability to reduce the acquisition time (from 202 to 41 seconds) of SWI while increasing the acceleration factor from 2 to 10, though at the cost of decreasing the SNR, contrast ratio, and the scores of visual assessments. The visibility of the substantia nigra-red nucleus and internal cerebral vein became unacceptable in CS6 to CS10. The basilar artery was well-distinguished, and diseases including cerebral microbleeds, cavernous angiomas, intracranial gliomas, venous malformations, and subacute hemorrhage were well-diagnosed in all compressed sensitivity encoding sequences.

CONCLUSIONS

Compressed sensitivity encoding factor 4 is recommended in routine practice. Compressed sensitivity encoding factor 10 is potentially a fast surrogate for distinguishing the basilar artery and detecting susceptibility-related abnormalities (eg, cerebral microbleeds, cavernous angiomas, gliomas, and venous malformation) at the sacrifice of visualization of the substantia nigra-red nucleus and internal cerebral vein.

Tolerance of peritoneal and residual renal function to intraperitoneal gadolinium-based agents: An animal experimental study of magnetic resonance peritoneography

BACKGROUND

MR (Magnetic resonance) peritoneography is sensible for continuous ambulatory peritoneal dialysis (CAPD)-related complications, which could offer excellent soft-tissue contrast and allows a multiplanar imaging evaluation of complications. However, there is no study about the optimal concentration of the gadolinium-based agents nor the side effects of gadolinium-based agents on peritoneum and residual renal function.

METHOD

Five different groups of uremic rats and two groups of normal rats were injected with a 40-ml mixture of peritoneal dialysate and gadolinium-based agents at varying concentrations prior to MR peritoneography. Thereafter, MR image obtained was evaluated by two experienced radiologists blinded to the concentrations. Peritoneal morphology and thickness of the uremic rats were also assessed using hematoxylin and eosin and Masson staining. Residual renal function was evaluated using serum creatinine levels and hematoxylin and eosin (HE) staining of pathological kidney sections.

RESULTS AND CONCLUSION

The gadolinium-based agents used in this experiment have no significant effect on residual renal function. There is no obvious difference in the image quality at the different gadolinium-based agents concentration. Due to the adverse effects of gadolinium-based agents in the previous studies, we suggest reducing the dose of gadolinium-based agents during MR peritoneography to the lowest limits.

Study on a new manner of the magnetization switching actuated by a unidirectional pulse current

A new writing scheme with a unidirectional pulse current is proposed for spin transfer torque (STT) based magnetic random-access memory (MRAM). To investigate the feasibility of the writing scheme, bilayered nano-pillars composed of a soft layer with small in-plane shape anisotropy and a hard layer with either large perpendicular anisotropy (PMA) or in-plane anisotropy (IMA) are designed and their switching behaviors are studied. It is found that in either type of bilayered nano-pillars, with the aid of the attached hard layer, the magnetization of the soft layer can be switched back and forth under a unidirectional pulse current. In an IMA/IMA nano-pillar, the magnetization of the free layer (FL) can achieve excellent alignment, which is in contrast to the IMA/PMA nano-pillar. By optimizing the dimensions and magnetic parameters of the IMA/IMA nano-pillar, a decently low switching current density (4.3 × 10¹¹A m^-2) and ultrashort switching time (<1 ns) can be reached. Based on these results, the unidirectional writing scheme is practical if an IMA/IMA bilayer is used to replace the FL in a magnetic tunnel junction. Considering that a unidirectional writing scheme can enable the application of materials with high spin polarization such as half metals, and avoid the injection of writing current into junction using a special design, it may be very promising for STT-MRAM.

[An optimized protocol of meniscus cell extraction for single-cell RNA sequencing]

OBJECTIVE

To optimize the protocol of meniscus cell extraction to enhance the efficiency of cell suspension preparation and maintain a high cell viability for single-cell RNA sequencing.

METHODS

We compared the efficiency of the routine cell extraction methods (short-time digestion and long-time digestion) and the optimized protocol for obtaining meniscus cell suspensions by evaluating the cell number obtained and the cell viability. Single-cell RNA sequencing datasets were analyzed to evaluate the stability of the cell suspension prepared using the optimized protocol. The reliability of the optimized protocol was assessed by comparing the single-cell RNA sequencing dataset obtained by the optimized protocol with published single-cell RNA sequencing datasets of the meniscus.

RESULTS

The optimized protocol harvested a greater number of cells (over 1×10⁵) than the routine protocols. The cell suspension prepared with the optimized protocol showed a cell viability higher than 80%, the highest among the 3 methods. Analysis of single-cell RNA sequencing datasets showed that the ratio of the mitochondrial genes was below 20% in over 80% of the cells. CD34⁺ cells, MCAM⁺ cells and COL1A1⁺ cells were identified in the datasets. Comparison with the publish datasets showed that the optimized protocol was capable of harvesting COL3A1⁺, COL1A1⁺, MYLK⁺, BMP2⁺, CD93⁺ and CDK1⁺ cells.

CONCLUSION

Single-cell suspension prepared from the meniscus can be stably obtained using the optimized protocol for single-cell RNA sequencing using the 10× Genomics platform.

[Diagnostic issues of Whipple's disease during chronic inflammatory rheumatism: About three cases]

INTRODUCTION

Whipple's disease (WD) can mimic chronic inflammatory rheumatism leading to incorrect prescription of tumor necrosis factor inhibitors (TNFI). Several complicated cases of WD have been reported during TNFI treatment which is strongly suspected to modify the host-pathogen relationship. Tropheryma whipplei asymptomatic carriage is high in the general population, making the diagnosis of WD more difficult face to unexplained arthritis.

OBSERVATIONS

We report three observations that illustrate situations for which the detection of T. whipplei might be valuable to investigate the differential diagnosis of inflammatory rheumatism.

CONCLUSION

The decision to check for T. whipplei infection should rely on individual clinical assessment. It should be considered in the absence of clinical response or in case of worsening of an inflammatory rheumatism under TNFI treatment, especially in front of atypical features. A systematic screening for T. whipplei before anti-TNF treatment seems unjustified since asymptomatic carriers are frequent.

Bisphenol A Exposure Disrupts Enamel Formation via EZH2-Mediated H3K27me3

Enamel formation is a serial and complex biological process, during which related genes are expressed progressively in a spatiotemporal manner. This process is vulnerable to environmental cues, resulting in developmental defects of enamel (DDE). However, how environmental factors are biologically integrated during enamel formation is still poorly understood. Here, we investigated the mechanism of DDE elicited by a model endocrine-disrupting chemical, bisphenol A (BPA), in mouse incisors. We show that BPA exposure leads to DDE in mouse incisors, as well as excessive proliferation in dental epithelial stem/progenitor cells. Western blotting, chromatin immunoprecipitation sequencing, and immunofluorescence staining revealed that this effect was accompanied by upregulation of a repressive mark, H3K27me3, in the labial cervical loop of mouse incisors. Perturbation of H3K27me3 methyltransferase EZH2 repressed the level of H3K27me3 and partially attenuated the excessive proliferation in dental epithelial stem/progenitor cells and DDE induced by BPA exposure. Overall, our results demonstrate the essential role of repressive histone modification H3K27me3 in DDE elicited by exposure to an endocrine-disrupting chemical.

Engagement among physicians fighting COVID-19: the mediating role of autonomy

Background

Keeping and improving work engagement among physicians fighting COVID-19 is important to healthy medical systems. In line with the job demands-resources model, optimism was expected to positively relate with job resources, leading to higher work engagement. However, the underlying mechanism between optimism, autonomy and work engagement has not been explored.

Aims

To examine whether optimism has a positive impact on work engagement via autonomy among physicians fighting COVID-19 in China.

Methods

This study was conducted among physicians in March 2020. A convenience sample was used to recruit physicians from the Wuhan Leishenshan Hospital and Wuhan Jinyintan Hospital. One hundred and four Chinese physicians working in the COVID-19 epidemic completed a survey measuring levels of autonomy, optimism and work engagement. The PROCESS macro (model 4) was used to test hypotheses about mediation.

Results

This current study found that optimism was related to increased autonomy, and autonomy was related to increased work engagement. The results of the bias-corrected bootstrap method suggested the indirect effect of optimism on work engagement via autonomy (Effect = 0.16, SE = 0.08, lower level confidence interval = 0.04, upper level confidence interval = 0.37), indicating a mediated relationship, in which autonomy is one mechanism to explain the link between optimism and increased work engagement.

Conclusions

This study follows an observational design, with in-depth analysis of the relationship between optimism, autonomy and work engagement. When management implements strategies to improve work engagement among physicians working in the COVID-19 epidemic, the mediating impact of autonomy on the association between optimism and work engagement should be considered.

Precision measurement of the neutral pion lifetime

The explicit breaking of the axial symmetry by quantum fluctuations gives rise to the so-called axial anomaly. This phenomenon is solely responsible for the decay of the neutral pion π⁰ into two photons (γγ), leading to its unusually short lifetime. We precisely measured the decay width Γ of the [Formula: see text] process. The differential cross sections for π⁰ photoproduction at forward angles were measured on two targets, carbon-12 and silicon-28, yielding [Formula: see text], where stat. denotes the statistical uncertainty and syst. the systematic uncertainty. We combined the results of this and an earlier experiment to generate a weighted average of [Formula: see text] Our final result has a total uncertainty of 1.50% and confirms the prediction based on the chiral anomaly in quantum chromodynamics.