TET2-mediated tumor cGAS triggers endothelial STING activation to regulate vasculature remodeling and anti-tumor immunity in liver cancer

Induction of tumor vascular normalization is a crucial measure to enhance immunotherapy efficacy. cGAS-STING pathway is vital for anti-tumor immunity, but its role in tumor vasculature is unclear. Herein, using preclinical liver cancer models in Cgas/Sting-deficient male mice, we report that the interdependence between tumor cGAS and host STING mediates vascular normalization and anti-tumor immune response. Mechanistically, TET2 mediated IL-2/STAT5A signaling epigenetically upregulates tumor cGAS expression and produces cGAMP. Subsequently, cGAMP is transported via LRRC8C channels to activate STING in endothelial cells, enhancing recruitment and transendothelial migration of lymphocytes. In vivo studies in male mice also reveal that administration of vitamin C, a promising anti-cancer agent, stimulates TET2 activity, induces tumor vascular normalization and enhances the efficacy of anti-PD-L1 therapy alone or in combination with IL-2. Our findings elucidate a crosstalk between tumor and vascular endothelial cells in the tumor immune microenvironment, providing strategies to enhance the efficacy of combinational immunotherapy for liver cancer.

Inhibition of ACLY overcomes cancer immunotherapy resistance via polyunsaturated fatty acids peroxidation and cGAS-STING activation

Adenosine 5'-triphosphate citrate lyase (ACLY) is a cytosolic enzyme that converts citrate into acetyl-coenzyme A for fatty acid and cholesterol biosynthesis. ACLY is up-regulated or activated in many cancers, and targeting ACLY by inhibitors holds promise as potential cancer therapy. However, the role of ACLY in cancer immunity regulation remains poorly understood. Here, we show that ACLY inhibition up-regulates PD-L1 immune checkpoint expression in cancer cells and induces T cell dysfunction to drive immunosuppression and compromise its antitumor effect in immunocompetent mice. Mechanistically, ACLY inhibition causes polyunsaturated fatty acid (PUFA) peroxidation and mitochondrial damage, which triggers mitochondrial DNA leakage to activate the cGAS-STING innate immune pathway. Pharmacological and genetic inhibition of ACLY overcomes cancer resistance to anti-PD-L1 therapy in a cGAS-dependent manner. Furthermore, dietary PUFA supplementation mirrors the enhanced efficacy of PD-L1 blockade by ACLY inhibition. These findings reveal an immunomodulatory role of ACLY and provide combinatorial strategies to overcome immunotherapy resistance in tumors.

[PI3K/Akt signaling pathway mediates the protective effect of endomorphin-1 postconditioning against myocardial ischemia-reperfusion injury in rats]

OBJECTIVE

To investigate the role of PI3K/Akt signaling pathway in mediating the protective effect of endomorphin-1 against myocardial ischemia-reperfusion (IR) injury.

OBJECTIVE

Fifty SD male rats were randomly divided into sham operation group, myocardial IR group, endomorphin-1 post-treatment group (EM50 group), endomorphin-1+wortmannin (a PI3K/Akt signaling pathway inhibitor) treatment group (EM50+Wort group), and wortmannin treatment group (Wort group). Rat models of myocardial IR injury were established by ligation of the left anterior descending coronary artery for 30 min followed by reperfusion for 120 min. The heart rate and mean arterial pressure were monitored during the experiment. Plasma levels of LDH, CK-MB, cTnI, IL-6, TNF-α, SOD and MDA were measured after reperfusion. The mRNA expression of Bax and Bcl-2 was detected using RT-PCR, and the expression of apoptosis-related protein cleaved caspase-3, phosphorylated Akt protein and total Akt protein in myocardial tissue was detected using Western blotting.

OBJECTIVE

Myocardial IR injury significantly decreased heart rate and blood pressure of the rats in comparison with the sham operation (P < 0.05). Compared with those in the IR group, the rats in EM50 group showed significantly increased heart rate and blood pressure (P < 0.05) with decreased plasma LDH, CK-MB, cTnI, IL-6, TNF-α and MDA levels (P < 0.05), increased SOD activity (P < 0.05), increased expression of p-Akt protein and Bcl-2 mRNA (P < 0.05), and decreased expression of Bax mRNA and cleaved caspase-3 protein (P < 0.05). In EM50+Wort group, the heart rate and blood pressure were significantly lowered (P < 0.05), plasma LDH, CK-MB, cTnI, IL-6, TNF-α and MDA levels increased (P < 0.05), SOD activity decreased (P < 0.05), the expression of p-Akt protein and Bcl-2 mRNA was reduced (P < 0.05), and the expression of Bax mRNA and cleaved caspase-3 protein increased (P < 0.05) as compared with those in EM50 group.

OBJECTIVE

EM-1 postconditioning can regulate cardiac myocyte apoptosis and reduce myocardial IR injury in rats. The PI3K/Akt signaling pathway may play a role in mediating the myocardial protective effects of EM-1 postconditioning.

[Sleep status associated with psychological and behavioral problems in adolescents and children]

Objective: To examine whether sleep status and social jet lag are related to the mental health behaviors in children and adolescents, providing a reference for preventing and improving children and adolescents' mental health behaviors. Methods: A large cross-section was conducted in Baoan District, Shenzhen, from April to May 2019. A total of 30 188 adolescents and children in grades 1-12 in 14 schools were included. The growth trajectory and health index questionnaire of primary and secondary school students were designed to evaluate the sleep status. Mental health behavior problems among students were accessed using the parents' and students' versions of the Strengths and Difficulties Questionnaire. After controlling for confounding factors of demographic variables, including gender, age, parental education level, academic performance, learning burden, and noise impact, a multivariate logistic regression model was used for statistical analyses. Results: The sleep duration of four grades students were 90.4％,90.1％, 98.2％, and 98.4％, respectively. 19.9％ did not have a post-lunch nap. 19.6％ had a wake-up delay of more than or equal to 2 h weekend morning. 35.1％ had an inconsistent bedtime and 15.5％ had an inconsistent awakening time. The multivariate logistic regression model showed that compared with 8-9 h, the sleep duration of elementary school juniors at night less than or equal to 7 h, 7-8 h increased the risk of psychological behavior problems. The sleep time more than 9 h was negatively correlated with psychological behavior problems. The sleep duration of elementary school seniors less than or equal to 7 h increased the risk of psychological behavior problems. The sleep duration of middle school and high school students less than or equal to 6 h increased psychological behavior problems. The ORs (95％CI) appeared as 2.53(1.85-3.47), 2.41(1.11-5.25), respectively. The ones with a sleep time more than 9 h also increased the risk, and ORs (95％CI) appeared as 2.37(1.40-4.01), 5.38 (1.79-16.1), respectively. Both the absence of post-lunch nap and the nap time less than 0.5 h were risk factors for psychological behavior problems in primary and middle school students. The nap time over 1-2 h was also a risk factor for high school students' psychological behavior problems. Waking up at irregular times in the morning, going to bed at varying times in the evening, and delaying getting up for more than or equal to 2 h on weekends were all risk factors for psychological and behavioral problems among primary and middle school students. The ORs (95％CI) of psychological behavior problems of elementary school juniors and seniors, middle school and high school students were 2.07 (1.45-2.97), 1.57 (1.09-2.26), 2.66 (2.06-3.44), 2.48 (1.96-3.15), respectively. Conclusions: Sleep duration, no post-lunch sleep, and daily intraindividual variability of sleep is positively associated with poor mental health. Additionally, social jet lag is associated with mental health problems in students. It is noted that delaying sleep within half an hour on the weekends of elementary school juniors is significantly associated with an increase in bad mental behavior.

[The relationship between migration time and the prevalence of myopia of children and adolescents aged 6-18 years old in Shenzhen]

Objective: To analyze the relationship between migration time and the prevalence of myopia of children and adolescents aged between 6 and 18 years old in Shenzhen. Methods: From April to May 2019, 26 618 children and adolescents from 14 schools in six streets of Baoan District, including Fuyong, Shajing, Xin'an, Xixiang, Songgang and Shiyan, were included in the study by using random cluster sampling method. The demographic characteristics, migration status, self-reported myopia, screen time in the last seven days, outdoor activities in the last one month and other information were collected through the questionnaire. The differences of myopia among children and adolescents with different characteristics were compared by χ² test, and the relationship between migration time and the prevalence of myopia was analyzed by multivariate unconditional logistic regression model. Results: The age of 26 618 study participants was (12.37±3.49) years old, and the overall prevalence of myopia was 49.4%. Multivariate logistic regression analysis showed that after controlling for relevant confounding factors, compared with migrant children and adolescents of migrant workers who migrated for 1-2 years, those of migrant workers who had migrated for more than 6 years had a higher risk of myopia [OR (95%CI): 1.48 (1.14-1.92)]. After being grouped by phase of school, in the lower grade group of primary school, the children and adolescents of migrant workers who had migrated for more than 6 years had a higher risk of myopia compared with those of migrant workers who migrated for 1-2 years [OR (95%CI): 1.96 (1.20-2.74)]. In the high school group, compared with the children and adolescents of migrant workers who migrated for 1-2 years, those of migrant workers who had migrated for 3-5 years and ≥6 years had a higher risk of myopia [OR (95%CI): 6.03 (1.29-28.15) and 6.52 (1.51-28.11), respectively]. Conclusion: The migration time is related to the prevalence of myopia of the children and adolescents of migrant workers.

NAD+ Metabolism Maintains Inducible PD-L1 Expression to Drive Tumor Immune Evasion

NAD⁺ metabolism is implicated in aging and cancer. However, its role in immune checkpoint regulation and immune evasion remains unclear. Here, we find nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme of the NAD⁺ biogenesis, drives interferon γ (IFNγ)-induced PD-L1 expression in multiple types of tumors and governs tumor immune evasion in a CD8⁺ T cell-dependent manner. Mechanistically, NAD⁺ metabolism maintains activity and expression of methylcytosine dioxygenase Tet1 via α-ketoglutarate (α-KG). IFNγ-activated Stat1 facilitates Tet1 binding to Irf1 to regulate Irf1 demethylation, leading to downstream PD-L1 expression on tumors. Importantly, high NAMPT-expressing tumors are more sensitive to anti-PD-L1 treatment and NAD⁺ augmentation enhances the efficacy of anti-PD-L1 antibody in immunotherapy-resistant tumors. Collectively, these data delineate an NAD⁺ metabolism-dependent epigenetic mechanism contributing to tumor immune evasion, and NAD⁺ replenishment combined with PD-(L)1 antibody provides a promising therapeutic strategy for immunotherapy-resistant tumors.

[Analysis on epidemic situation and spatiotemporal changes of COVID-19 in Anhui]

We used the epidemic data of COVID-19 published on the official website of the municipal health commissions in Anhui province to map the spatiotemporal changes of confirmed cases, fit the epidemic situation by the population growth curve at different stages and analyze the epidemic situation in Anhui Province. It was found that the cumulative incidence of COVID-19 was 156/100 000 by February 18, 2020 and the trend of COVID-19 epidemic declined after February 7 with a change from J-shaped curve to S-shaped curve. As the reporting time of cases might be 3-5 days later than the actual onset time, the number of new cases in Anhui province actually began to decline around February 2 to February 4, 2020.

Overexpression of eIF4E in Saccharomyces cerevisiae causes slow growth and decreased alpha-factor response through alterations in CLN3 expression

The association of G(1) cyclins and Cdc28/cyclin-dependent protein kinase catalyzes the cell cycle entry (Start) in budding yeast. Activation of Start is presumed to be triggered by a post-transcriptional increase in Cln3 during early G(1). Cells arrested by mating pheromone show a loss of cyclin-dependent protein kinase activity caused by transcriptional shutoff of cyclins and/or inhibition by Far1. We report that overexpression of eIF4E (Cdc33), a rate-limiting translation initiation factor, causes an increase in CLN3 mRNA translation, which results in increased expression of CLN2 and in slow growth and decreased alpha-factor response. This phenotype was abrogated in a Deltacln3 or Deltacln2 background. We isolated the transcription factor MBP1 as a multicopy suppressor of the growth and alpha-factor response defects. Furthermore, elevated MBP1, a transcriptional regulator of cyclins, altered the transcriptional start site in CLN3 mRNA, shifting it 45 nucleotides upstream of the normal. This lengthened 5'-untranslated region likely reduces translation efficiency and down-regulates CLN3 protein synthesis, thereby correcting for the excess translation promoted by elevated Cdc33. In addition, the CLN2 mRNA level returned to normal. We propose that regulation of translation initiation by Cdc33 plays a pivotal role in the activation of Start and cell cycle progression in budding yeast.

Messenger RNA translation state: the second dimension of high-throughput expression screening

Technological advances over the past 10 years have generated powerful tools for parallel analysis of complex biological problems. Among these new technologies, DNA arrays have provided an important experimental approach for identifying changes in the levels of individual mRNA molecules during important cellular transitions. However, cellular behavior is dictated not by mRNA levels, but by the proteins translated from the individual mRNA species. We report a high-throughput method for simultaneously monitoring the translation state and level of individual mRNA species. Messenger RNAs from resting and mitogenically activated fibroblasts were separated, according to degree of ribosome loading, into well-translated and under-translated pools. cDNA probes generated from these fractions were used to interrogate cDNA arrays. Among approximately 1,200 genes analyzed, less than 1% were found to be translationally regulated in response to mitogenic activation, demonstrating the strong selectivity of this regulatory mechanism. This high-throughput approach is shown to be an effective tool for superimposing translation profile on mRNA level for large numbers of genes, as well as for identifying translationally regulated genes for further study.

High-pressure-assisted reconstitution of recombinant chloroperoxidase

An expression vector containing a T7 promoter and an OmpA signal sequence followed by the DNA sequence of mature chloroperoxidase from the fungus Caldariomyces fumago has been transformed into Escherichia coli. This construct gave high-level expression of apochloroperoxidase when induced with isopropyl thiogalactopyranoside. The nonglycosylated apoenzyme was secreted into periplasmic space. The recombinant apochloroperoxidase was expressed at a level representing about 2% of the total cellular protein. Before conversion to holoenzyme, the apochloroperoxidase was denatured in 8 M urea and partially purified by DEAE chromatography. Maximum yields of holoenzyme were obtained when the denatured apochloroperoxidase, dissolved in a refolding buffer containing iron protoporphyrin IX, calcium ions, and oxidized glutathione, was subjected to high pressure (207 MPa) at -12 degrees C and then allowed to refold at atmospheric pressure and room temperature. The recombinant holoenzyme was characterized by absorption and CD spectroscopy and tested for halogenation and peroxidation activity. The yield of active holochloroperoxidase was about 5% when high-pressure treatment was used as part of the reconstitution process. In the absence of pressure treatment, holoenzyme was formed at about the 1% level. The holochloroperoxidase preparations which resulted from high-pressure treatment showed, upon return to atmospheric pressure, a considerably higher content of native-like secondary structure compared to the nonpressurized preparations. These experiments show that active recombinant chloroperoxidase molecules can be produced, and prove that glycosylation is not a mandatory requirement for chloroperoxidase refolding.

Pharmacological properties of galenical preparation. XV. Pharmacokinetics study of evocarpine and its metabolite in rats

It is known that when methanol extract of Evodia fruit is orally administered, 5-(1,4-dihydro-1-methyl-4-oxo-2-quinolin-2-yl) pentanoic acid (EVCA) is excreated as a matabolite in rat urine. In this study, we separated Evodia fruit extract into major alkaloids administered each alkaloid individually to male Wistar rats. Consequently, it was demonstrated that the original substance of the metabolite are evocarpine and its analogues, dihydroevocarpine and 1-methyl-2-undecenyl-4(1H)-quinolone. Investigation of a blood sample after oral administration of evocarpine by high performance liquid chromatography confirmed that the substance was absorbed without alteration. Pharmacokinetics of evocarpine after intravenous injection was expressed in a one-compartment model, showing a linear elimination of plasma evocarpine up to a dosage of 75 mg/kg. Total plasma clearance (CL), volume of distribution (Vd), and half-life (T1/2) of evocarpine were 60 ml/min.kg, 3.21/kg and 0.6 h-1, respectively. Metabolic ratio of evocarpine into EVCA after intravenous injection was 15.4%, and absorption ratio of the unaltered compound calculated from the levels of AUC after oral administration and intravenous injection was 4.7%. In this paper, it is shown that evocarpine is absorbed amount 100% when it is administered orally.