CRL4DCAF8 and USP11 oppositely regulate the stability of myeloid leukemia factors (MLFs).

Myeloid leukemia factors (MLF1 and MLF2) are proteins associated with leukemia and several other cancers. However, little is known about the regulatory mechanisms underlying the stability of these proteins. Here, we show that DDB1 and CUL4 associated factor 8 (DCAF8), which can form a functional E3 ligase complex (CRL4DCAF8), has a strong interaction with the MLF2 protein. DCAF8 could promote MLF2 degradation through the ubiquitin-proteasome pathway. In contrast, ubiquitin specific peptidase 11 (USP11) associates with MLF2, thereby increasing its stability. Since MLF1 is highly related to MLF2, we demonstrated that MLF1 also interacts with DCAF8 and USP11, suggesting that CRL4DCAF8 and USP11 may also regulate the expression of MLF1. TCGA analysis revealed that both the myeloid leukemia factors (MLF1 and MLF2) show significant differential expression in various tumors. The results of our study indicate that CRL4DCAF8 and USP11 play opposite roles in the regulation of MLF1 and MLF2, which may, in turn, affect their biological functions in various cancers.

TRAF-interacting protein with forkhead-associated domain (TIFA) transduces DNA damage-induced activation of NF-κB.

DNA damage-induced NF-κB activation and the secretion of inflammatory cytokines play crucial roles in carcinogenesis and cellular senescence. However, the underlying mechanisms, especially the initial sensors and transducers connecting the nuclear DNA damage signal with cytoplasmic NF-κB activation remain incompletely understood. Here, we report that TRAF-interacting protein with forkhead-associated domain (TIFA), an established NF-κB activator in the cytosol, unexpectedly exhibited nuclear translocation and accumulation on damaged chromatin following genotoxic stress. Accordingly, we also found that DNA damage-induced transcriptional activation and the resulting secretion of classic NF-κB targets, including interleukin (IL)-6 and IL-8, was greatly enhanced in TIFA-overexpressing cells compared with control cells. Mechanistically, DNA damage-induced TIFA phosphorylation at threonine 9 (pThr-9), and this phosphorylation event, involving the pThr-binding forkhead-associated domain, was crucial for its enrichment on damaged chromatin and subsequent NF-κB activation. Moreover, in conjunction with its partner protein, the E3 ligase TNF receptor-associated factor 2 (TRAF2), TIFA relayed the DNA damage signals by stimulating ubiquitination of NF-κB essential modulator (NEMO), whose sumoylation, phosphorylation, and ubiquitination were critical for NF-κB's response to DNA damage. Consistently, TRAF2 knockdown suppressed TIFA overexpression-enhanced NEMO ubiquitination under genotoxic stress, and a unphosphorylatable Thr-9-mutated TIFA variant had only minor effects on NEMO poly-ubiquitination. Finally, in agreement with the model of DNA damage-associated secretory senescence barrier against carcinogenesis, ectopic TIFA expression limited proliferation of multiple myeloma cancer cells. In conclusion our results indicate that TIFA functions as a key transducer in DNA damage-induced NF-κB activation.

Epigenetic activation of secretory phenotypes in senescence by the FOXQ1-SIRT4-GDH signaling.

Although metabolic reprogramming is characterized as a hallmark of aging, implications of the crucial glutamate dehydrogenase (GDH) in human senescence remain poorly understood. Here, we report that GDH activity is significantly increased in aged mice and senescent human diploid fibroblasts. This enzymatic potentiation is associated with de-repression of GDH from its functionally suppressive ADP-ribosylation modification catalyzed by NAD-dependent ADP-ribosyltransferase/deacetylase SIRT4. A series of transcription analyses led to the identification of FOXQ1, a forkhead family transcription factor (TF), responsible for the maintenance of SIRT4 expression levels in juvenile cells. However, this metabolically balanced FOXQ1-SIRT4-GDH axis, is shifted in senescence with gradually decreasing expressions of FOXQ1 and SIRT4 and elevated GDH activity. Importantly, pharmaceutical inhibition of GDH suppresses the aberrantly activated transcription of IL-6 and IL-8, two major players in senescence-associated secretory phenotype (SASP), and this action is mechanistically associated with erasure of the repressive H3K9me3 (trimethylation of lysine 9 on histone H3) marks at IL-6 and IL-8 promoters, owing to the requirement of α-ketoglutaric acid (α-KG) from GDH-mediated glutamate dehydrogenase reaction as a cofactor for histone demethylation. In supplement with the phenotypic evidence from FOXQ1/SIRT4/GDH manipulations, these data support the integration of metabolism alterations and epigenetic regulation in driving senescence progression and highlight the FOXQ1-SIRT4-GDH axis as a novel druggable target for improving human longevity.

Biomarkers of aging.

Aging biomarkers are a combination of biological parameters to (i) assess age-related changes, (ii) track the physiological aging process, and (iii) predict the transition into a pathological status. Although a broad spectrum of aging biomarkers has been developed, their potential uses and limitations remain poorly characterized. An immediate goal of biomarkers is to help us answer the following three fundamental questions in aging research: How old are we? Why do we get old? And how can we age slower? This review aims to address this need. Here, we summarize our current knowledge of biomarkers developed for cellular, organ, and organismal levels of aging, comprising six pillars: physiological characteristics, medical imaging, histological features, cellular alterations, molecular changes, and secretory factors. To fulfill all these requisites, we propose that aging biomarkers should qualify for being specific, systemic, and clinically relevant.

Oridonin Delays Aging Through the AKT Signaling Pathway.

Aging is a major risk factor for chronic diseases and disability in humans. Nowadays, no effective anti-aging treatment is available clinically. In this study, oridonin was selected based on the drug screening strategy similar to Connectivity MAP (CMAP) but upon transcriptomes of 102 traditional Chinese medicines treated cell lines. Oridonin is a diterpenoid isolated from Rabdosia rubescens. As reported, Oridonin exhibits a variety of pharmacological activities, including antitumor, antibacterial and anti-inflammatory activities. Here, we found that oridonin inhibited cellular senescence in human diploid fibroblasts (2BS and WI-38), manifested by decreased senescence-associated ß-galactosidase (SA-ß-gal) staining. Compared with the elderly control group, the positive cell rate in the oridonin intervention group was reduced to 48.5%. Notably, oridonin prolonged the lifespan of yeast by 48.9%, and extended the average life span of naturally aged mice by 21.6%. Our mice behavior experiments exhibited that oridonin significantly improved the health status of naturally aged mice. In addition, oridonin also delayed doxorubicin-induced cellular senescence and mouse senescence. Compared with the model group, the percentage of SA-ß-gal positive cells in the oridonin treatment group was reduced to 59.8%. It extended the average lifespan of mice by 53.8% and improved healthspan. Mechanistically, we showed that oridonin delayed aging through the AKT signaling pathway and reversed the genetic changes caused by doxorubicin-induced cell senescence. Therefore, oridonin is a potential candidate for the development of anti-aging drugs.

The roles of inactivated vaccines in older patients with infection of Delta variant in Nanjing, China.

BACKGROUND: The coronavirus disease 2019 (COVID-19) is spreading around the world. The COVID-19 vaccines may improve concerns about the pandemic. However, the roles of inactivated vaccines in older patients (aged ≥60 years) with infection of Delta variant were less studied. METHODS: We classified the older patients with infection of Delta variant into three groups based on the vaccination status: no vaccination (group A, n = 113), one dose of vaccination (group B, n = 46), and two doses of vaccination (group C, n = 22). Two inactivated COVID-19 vaccines (BBIBP-CorV or CoronaVac) were evaluated in this study. The demographic data, laboratory parameters, and clinical severity were recorded. RESULTS: A total of 181 older patients with infection of Delta variant were enrolled. 111 (61.3%) patients had one or more co-morbidities. The days of "turn negative" and hospital stay in Group C were lower than those in the other groups (P < 0.05). The incidences of multiple organ dysfunction syndrome (MODS), septic shock, acute respiratory distress syndrome (ARDS), acute kidney injury, and cardiac injury in Group A were higher than those in the other groups (P < 0.05). The MV-free days and ICU-free days during 28 days in Group A were also lower than those in the other groups (P < 0.05). In patients with co-morbidities, vaccinated cases had lower incidences of MODS (P = 0.015), septic shock (P = 0.015), and ARDS (P = 0.008). CONCLUSIONS: The inactivated COVID-19 vaccines were effective in improving the clinical severity of older patients with infection of Delta variant.

Interleukin-9 promotes intestinal barrier injury of sepsis: a translational research.

BACKGROUND: Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. Intestinal mucosal barrier injury is one of the important manifestations of sepsis. Interleukin-9 (IL-9) and IL-9-producing CD4(+) T cells were emerging pro-inflammatory mediators with development of intestinal injury. However, it is unclear whether IL-9 is related to the intestinal barrier injury of sepsis. METHODS: To investigate the roles of IL-9-producing CD4(+) T cells and IL-9 in the process of barrier injury in sepsis, serum IL-9-producing CD4(+) T cell percentages, IL-9, and D-lactate levels were measured in septic patients and controls. The markers of barrier function in serum and intestinal tissue were also collected in septic rats. Moreover, the barrier injury degree and survival rate of septic rats were also investigated after increasing or interfering with IL-9 expression. RESULTS: The serum IL-9-producing CD4(+) T cell percentages, IL-9, and D-lactate levels were significantly higher in septic patients or rats than those in controls. IL-9-producing CD4(+) T cells and IL-9 levels were positively correlated with D-lactate levels and had a high predictive value of 28-day mortality in septic patients. The non-survivors had significantly higher serum T cell percentages, IL-9, and D-lactate levels compared with survivors. In septic rats, IL-9 increased the expression levels of D-lactate, whereas that decreased the expression levels of zonula occludens 1. Moreover, the barrier injury was aggravated or alleviated by increasing or interfering with IL-9 expression, respectively. Survival rate analysis also showed that IL-9 decreased the 14-day survival rate of septic rats. CONCLUSION: IL-9 is closely related to intestinal mucosal barrier injury and mortality in sepsis. IL-9 blockade has the potential to improve the barrier injury in sepsis. TRIAL REGISTRATION: The study was registered at ClinicalTrials.gov (ID: NCT03791866, Date: December 2018).

CRL4DCAF8 dependent opposing stability control over the chromatin remodeler LSH orchestrates epigenetic dynamics in ferroptosis.

Despite the emerging evidence on ferroptosis implicated in diverse pathologies, molecular linkage between oxidative inducers and chromatin as epigenetic memory carrier for its propagation remains elusive. Here, we report the identification of two WD40 proteins DCAF8 and WDR76 as substrate adapter and molecular inhibitor respectively of the Cullin-4 RING ubiquitin ligase (CRL4) system for stability control of chromatin remodeler LSH. Degradation analysis and CRL4-DCAF8 complex reconstitution demonstrate that CRL4DCAF8 is a bona fide E3 ligase for LSH. In contrast, WDR76 antagonizes DCAF8-targeted LSH proteolysis through competitive inhibition of the holo-CRL4DCAF8-LSH complex assembly. Importantly, this opposing regulatory strategy is utilized in lipid hydroperoxide induced ferroptosis, where we identify key redox homeostasis genes significantly regulated by the DCAF8/WDR76/LSH axis through transcriptomic epistasis analysis. This regulation is mechanistically attributed to DNA hydroxymethylation fostered WDR76 interaction with LSH and increased ratio of DCAF8 to WDR76 for antagonistic LSH association accompanying decreased DNA oxidation along with ROS overproduction. Evaluation of epigenetic dynamics at ferroptosis gene promoters reveals linker histone H1- and LSH-associated transcriptional repression is coordinately removed upon lipid peroxidation stress. Together with the phenotypes driven by WDR76 and DCAF8 manipulations, these data identify DCAF8- and WDR76-adapted oxidative damage sensing through DNA hydroxymethylation for LSH degradation control as a crucial nexus in epigenetic regulation of ferroptosis.

Prediction of drug efficacy from transcriptional profiles with deep learning.

Drug discovery focused on target proteins has been a successful strategy, but many diseases and biological processes lack obvious targets to enable such approaches. Here, to overcome this challenge, we describe a deep learning-based efficacy prediction system (DLEPS) that identifies drug candidates using a change in the gene expression profile in the diseased state as input. DLEPS was trained using chemically induced changes in transcriptional profiles from the L1000 project. We found that the changes in transcriptional profiles for previously unexamined molecules were predicted with a Pearson correlation coefficient of 0.74. We examined three disorders and experimentally tested the top drug candidates in mouse disease models. Validation showed that perillen, chikusetsusaponin IV and trametinib confer disease-relevant impacts against obesity, hyperuricemia and nonalcoholic steatohepatitis, respectively. DLEPS can generate insights into pathogenic mechanisms, and we demonstrate that the MEK-ERK signaling pathway is a target for developing agents against nonalcoholic steatohepatitis. Our findings suggest that DLEPS is an effective tool for drug repurposing and discovery.

Heparin-binding protein as a biomarker of gastrointestinal dysfunction in critically ill patients: a retrospective cross-sectional study in China.

OBJECTIVE: To investigate the association of plasma heparin-binding protein (HBP) with the development of acute gastrointestinal injury (AGI) in critically ill patients. DESIGN: Clinical retrospective cross-sectional study. SETTING: A general teaching hospital in China. PARTICIPANTS: Adult patients (age ≥18 years) admitted to our department with an intensive care unit (ICU) stay ≥5 days. MAIN OUTCOME MEASURES: HBP levels were recorded twice or more within 5 days after admission. The initial AGI grades and the worst AGI grades within 5 days after admission, the number of patients receiving total enteral nutrition (TEN) and the number of patients with feeding intolerance (FI) and with sepsis were also recorded, along with some clinical severity and outcome variables. RESULTS: From June 2018 to May 2019, 221 patients were enrolled in this study. We divided patients into four groups based on the HBP values: HBP ≤20 ng/mL, 20100 ng/mL. Significant differences were found in the ratios of AGI deterioration and TEN and the incidence rates of FI and sepsis among the four groups. Differences were also found among the groups regarding the worst AGI grades. The area under receiver operating characteristic curves for AGI deterioration, severe AGI (grades II or above), TEN and FI were 0.738 (p=0.001), 0.774 (p<0.001), 0.810 (p<0.001) and 0.729 (p=0.001), respectively. The optimal HBP cut-off values for AGI deterioration and severe AGI were 53.27 ng/mL and 41.26 ng/mL, respectively. However, no differences in ICU duration or 28-day mortality were found. CONCLUSIONS: HBP levels were associated with gastrointestinal dysfunction in critically ill patients. Increased HBP was positively correlated with sepsis but it was not correlated with 28-day mortality.

Acetylation of FOXM1 is essential for its transactivation and tumor growth stimulation.

Forkhead box transcription factor M1 (FOXM1) plays crucial roles in a wide array of biological processes, including cell proliferation and differentiation, the cell cycle, and tumorigenesis by regulating the expression of its target genes. Elevated expression of FOXM1 is frequently observed in a multitude of malignancies. Here we show that FOXM1 can be acetylated by p300/CBP at lysines K63, K422, K440, K603 and K614 in vivo. This modification is essential for its transactivation on the target genes. Acetylation of FOXM1 increases during the S phase and remains high throughout the G2 and M phases, when FOXM1 transcriptional activity is required. We find that the acetylation-deficient FOXM1 mutant is less active and exhibits significantly weaker tumorigenic activities compared to wild-type FOXM1. Mechanistically, the acetylation of FOXM1 enhances its transcriptional activity by increasing its DNA binding affinity, protein stability, and phosphorylation sensitivity. In addition, we demonstrate that NAD-dependent histone deacetylase SIRT1 physically binds to and deacetylates FOXM1 in vivo. The deacetylation of FOXM1 by SIRT1 attenuates its transcriptional activity and decreases its protein stability. Together, our findings demonstrate that the reversible acetylation of FOXM1 by p300/CBP and SIRT1 modulates its transactivation function.

Transmission of Tomato Yellow Leaf Curl Virus by Bemisia tabaci as Affected by Whitefly Sex and Biotype.

Bemisia tabaci is a serious pest of vegetables and other crops worldwide. The most damaging and predominant B. tabaci biotypes are B and Q, and both are vectors of tomato yellow leaf curl virus (TYLCV). Previous research has shown that Q outperforms B in many respects but comparative research is lacking on the ability of B and Q to transmit viruses. In the present study, we tested the hypothesis that B and Q differ in their ability to transmit TYLCV and that this difference helps explain TYLCV outbreaks. We compared the acquisition, retention, and transmission of TYLCV by B and Q females and males. We found that Q females are more efficient than Q males, B females, and B males at TYLCV acquisition and transmission. Although TYLCV acquisition and transmission tended to be greater for B females than B males, the differences were not statistically significant. Based on electrical penetration graphs determination of phloem sap ingestion parameters, females fed better than males, and Q females fed better than Q males, B females, or B males. These results are consistent with the occurrences of TYLCV outbreaks in China, which have been associated with the spread of Q rather than B.