Nuclear Activity Research Articles

Iguratimod suppresses sclerostin and receptor activator of NF-κB ligand production via the extracellular signal–regulated kinase/early growth response protein 1/tumor necrosis factor alpha pathway in osteocytes and ameliorates disuse osteoporosis in mice

Disuse osteoporosis is a prevalent complication among patients afflicted with rheumatoid arthritis (RA). Although reports have shown that the antirheumatic drug iguratimod (IGU) ameliorates osteoporosis in RA patients, details regarding its effects on osteocytes remain unclear. The current study examined the effects of IGU on osteocytes using a mouse model of disuse-induced osteoporosis, the pathology of which crucially involves osteocytes. A reduction in distal femur bone mass was achieved after 3 weeks of hindlimb unloading in mice, which was subsequently reversed by intraperitoneal IGU treatment (30 mg/kg; five times per week). Histology revealed that hindlimb-unloaded (HLU) mice had significantly increased osteoclast number and sclerostin-positive osteocyte rates, which were suppressed by IGU treatment. Moreover, HLU mice exhibited a significant decrease in osteocalcin-positive cells, which was attenuated by IGU treatment. In vitro, IGU suppressed the gene expression of receptor activator of NF-κB ligand (RANKL) and sclerostin in MLO-Y4 and Saos-2 cells, which inhibited osteoclast differentiation of mouse bone marrow cells in cocultures. Although IGU did not affect the nuclear translocation or transcriptional activity of NF-κB, RNA sequencing revealed that IGU downregulated the expression of early growth response protein 1 (EGR1) in osteocytes. HLU mice showed significantly increased EGR1- and tumor necrosis factor alpha (TNFα)-positive osteocyte rates, which were decreased by IGU treatment. EGR1 overexpression enhanced the gene expression of TNFα, RANKL, and sclerostin in osteocytes, which was suppressed by IGU. Contrarily, small interfering RNA-mediated suppression of EGR1 downregulated RANKL and sclerostin gene expression. These findings indicate that IGU inhibits the expression of EGR1, which may downregulate TNFα and consequently RANKL and sclerostin in osteocytes. These mechanisms suggest that IGU could potentially be used as a treatment option for disuse osteoporosis by targeting osteocytes.

Lipoprotein signal peptidase-deficient Streptococcus pneumoniae exhibits impaired Toll-like receptor 2-stimulatory activity.

Streptococcus pneumoniae is a causative agent of community-acquired pneumonia. Upon pneumococcal infection, innate immune cells recognize pneumococcal lipoproteins via Toll-like receptor 2and induce inflammation. Here, we generated a strain of S. pneumoniae deficient in lipoprotein signal peptidase (LspA), a transmembrane type II signal peptidase required for lipoprotein maturation, to investigate the host immune response against this strain. Triton X-114 phase separation revealed that lipoprotein expression was lower in the LspA-deficient strain than in the wild-type strain. Additionally, the LspA-deficient strain decreased nuclear factor-κB activation and cytokine production in THP-1 cells, indicating impaired innate immune response against the strain.

Protective effects of Prussian blue nanozyme against sepsis-induced acute lung injury by activating HO-1

Sepsis is a life-threatening condition involving dysfunctional organ responses stemming from dysregulated host immune reactions to various infections. The lungs are most prone to failure during sepsis, resulting in acute lung injury (ALI). ALI is associated with oxidative stress and inflammation, and current therapeutic strategies are limited. To develop a more specific treatment, this study aimed to synthesise Prussian blue nanozyme (PBzyme), which can reduce oxidative stress and inflammation, to alleviate ALI. PBzyme with good biosafety was synthesised using a modified hydrothermal method. PBzyme was revealed to be an activator of haem oxygenase-1 (HO-1), improving survival rate and ameliorating lung injury in mice. Zinc protoporphyrin, an inhibitor of HO-1, inhibited the prophylactic therapeutic efficacy of PBzyme on ALI, and affected the nuclear factor-κB signaling pathway and activity of HO-1. This study demonstrates that PBzyme can alleviate oxidative stress and inflammation through HO-1 and has a prophylactic therapeutic effect on ALI. This provides a new strategy and direction for the clinical treatment of sepsis-induced ALI.

RND3 Potentiates Proinflammatory Activation through NOTCH Signaling in Activated Macrophages.

Macrophage activation is a complex process with multiple control elements that ensures an adequate response to the aggressor pathogens and, on the other hand, avoids an excess of inflammatory activity that could cause tissue damage. In this study, we have identified RND3, a small GTP-binding protein, as a new element in the complex signaling process that leads to macrophage activation. We show that RND3 expression is transiently induced in macrophages activated through Toll receptors and potentiated by IFN-γ. We also demonstrate that RND3 increases NOTCH signaling in macrophages by favoring NOTCH1 expression and its nuclear activity; however, Rnd3 expression seems to be inhibited by NOTCH signaling, setting up a negative regulatory feedback loop. Moreover, increased RND3 protein levels seem to potentiate NFκB and STAT1 transcriptional activity resulting in increased expression of proinflammatory genes, such as Tnf-α, Irf-1, or Cxcl-10. Altogether, our results indicate that RND3 seems to be a new regulatory element which could control the activation of macrophages, able to fine tune the inflammatory response through NOTCH.

Regulation of YAP Promotor Accessibility in Endothelial Mechanotransduction.

Endothelial cells are constantly exposed to mechanical forces in the form of fluid shear stress, extracellular stiffness, and cyclic strain. The mechanoresponsive activity of YAP (Yes-associated protein) and its role in vascular development are well described; however, whether changes to transcription or epigenetic regulation of YAP are involved in these processes remains unanswered. Furthermore, how mechanical forces are transduced to the nucleus to drive transcriptional reprogramming in endothelial cells is poorly understood. The YAP target gene, AmotL2 (angiomotin-like 2), is a junctional mechanotransducer that connects cell-cell junctions to the nuclear membrane via the actin cytoskeleton. We applied mechanical manipulations including shear flow, stretching, and substrate stiffness to endothelial cells to investigate the role of mechanical forces in modulating YAP transcription. Using in vitro and in vivo endothelial depletion of AmotL2, we assess nuclear morphology, chromatin organization (using transposase-accessible chromatin sequencing), and whole-mount immunofluorescent staining of the aorta to determine the regulation and functionality of YAP. Finally, we use genetic and chemical inhibition to uncouple the nuclear-cytoskeletal connection to investigate the role of this pathway on YAP transcription. Our results reveal that mechanical forces sensed at cell-cell junctions by the YAP target gene AmotL2 are directly involved in changes in global chromatin accessibility and activity of the histone methyltransferase EZH2, leading to modulation of YAP promotor activity. Functionally, shear stress-induced proliferation of endothelial cells in vivo was reliant on AmotL2 and YAP/TAZ (transcriptional coactivator with PDZ-binding motif) expression. Mechanistically, uncoupling of the nuclear-cytoskeletal connection from junctions and focal adhesions led to altered nuclear morphology, chromatin accessibility, and YAP promotor activity. Our findings reveal a role for AmotL2 and nuclear-cytoskeletal force transmission in modulating the epigenetic and transcriptional regulation of YAP to maintain a mechano-enforced positive feedback loop of vascular homeostasis. These findings may offer an explanation as to the proinflammatory phenotype that leads to aneurysm formation observed in AmotL2 endothelial deletion models.

FERM domain-containing proteins are active components of the cell nucleus.

The FERM domain is a conserved and widespread protein module that appeared in the common ancestor of amoebae, fungi, and animals, and is therefore now found in a wide variety of species. The primary function of the FERM domain is localizing to the plasma membrane through binding lipids and proteins of the membrane; thus, for a long time, FERM domain-containing proteins (FDCPs) were considered exclusively cytoskeletal. Although their role in the cytoplasm has been extensively studied, the recent discovery of the presence and importance of cytoskeletal proteins in the nucleus suggests that FDCPs might also play an important role in nuclear function. In this review, we collected data on their nuclear localization, transport, and possible functions, which are still scattered throughout the literature, with special regard to the role of the FERM domain in these processes. With this, we would like to draw attention to the exciting, new dimension of the role of FDCPs, their nuclear activity, which could be an interesting novel direction for future research.

IbNIEL-mediated degradation of IbNAC087 regulates jasmonic acid-dependent salt and drought tolerance in sweet potato.

Sweet potato (Ipomoea batatas [L.] Lam.) is a crucial staple and bioenergy crop. Its abiotic stress tolerance holds significant importance in fully utilizing marginal lands. Transcriptional processes regulate abiotic stress responses, yet the molecular regulatory mechanisms in sweet potato remain unclear. In this study, a NAC (NAM, ATAF1/2, and CUC2) transcription factor, IbNAC087, was identified, which is commonly upregulated in salt- and drought-tolerant germplasms. Overexpression of IbNAC087 increased salt and drought tolerance by increasing jasmonic acid (JA) accumulation and activating reactive oxygen species (ROS) scavenging, whereas silencing this gene resulted in opposite phenotypes. JA-rich IbNAC087-OE (overexpression) plants exhibited more stomatal closure than wild-type (WT) and IbNAC087-Ri plants under NaCl, polyethylene glycol, and methyl jasmonate treatments. IbNAC087 functions as a nuclear transcriptional activator and directly activates the expression of the key JA biosynthesis-related genes lipoxygenase (IbLOX) and allene oxide synthase (IbAOS). Moreover, IbNAC087 physically interacted with a RING-type E3 ubiquitin ligase NAC087-INTERACTING E3 LIGASE (IbNIEL), negatively regulating salt and drought tolerance in sweet potato. IbNIEL ubiquitinated IbNAC087 to promote 26S proteasome degradation, which weakened its activation on IbLOX and IbAOS. The findings provide insights into the mechanism underlying the IbNIEL-IbNAC087 module regulation of JA-dependent salt and drought response in sweet potato and provide candidate genes for improving abiotic stress tolerance in crops.

SIRT7 promotes Hippo/YAP activation and cancer cell proliferation in hepatocellular carcinoma via suppressing MST1.

Abnormal activation of the oncogene YAP in the Hippo pathway is a major feature in liver cancer and inactivation of MST1/2 has been shown to be responsible for the overactivation of YAP that led to tumorigenesis. However, mechanisms underlying MST1/2 dysregulation remain poorly understood. RNA-seq analysis and genome (KEGG) pathway enrichment analysis were used to identify genes and pathways that were regulated by SIRT7. qRT-PCR, ChIP, and luciferase assay were used to investigate transcriptional regulation. Mass spectrometry, co-immunoprecipitation and immunoprecipitation were used to exam protein-protein interaction and post-transcriptional modification. A xenograft mouse model was used to confirm the effect of SIRT7 and SIRT7 inhibitors on hepatocellular carcinoma (HCC) proliferation invivo. We found that SIRT7 suppresses MST1 by both transcriptional regulation and post-transcriptional modification, which in turn promotes YAP nuclear localization and transcriptional activation in liver cancer. Mechanistically, we revealed that SIRT7 suppresses MST1 transcription by binding to the MST1 promoter and inducing H3K18 deacetylation in its promoter region. In addition, SIRT7 directly binds to and deacetylates MST1, which primes acetylation-dependent MST1 ubiquitination and protein degradation. In clinical samples, we confirmed a negative correlation between SIRT7 and MST1 protein levels, and high SIRT7 expression correlated with elevated YAP expression and nuclear localization. In addition, SIRT7 specific inhibitor 2800Z sufficiently inhibited HCC growth by disrupting the SIRT7/MST1/YAP axis. Our data thus revealed the previously undescribed function of SIRT7 in regulating the Hippo pathway in HCC and further proved that targeting SIRT7 might provide novel therapeutic options for the treatment of liver cancer.

Impact of uranium on antibiotic resistance in activated sludge

The emergence of antibiotic resistance genes (ARGs) and antibiotic-resistant bacteria (ARB) in the environment is well established as a human health crisis. The impact of radioactive heavy metals on ecosystems and ultimately on human health has become a global issue, especially for the regions suffering various nuclear activities or accidents. However, whether the radionuclides can affect the fate of antibiotic resistance in bacteria remains poorly understood. Here, the dynamics of ARB, three forms of ARGs—intracellular ARGs (iARGs), adsorbed extracellular ARGs (aeARGs), and free extracellular ARGs (feARGs)—and microbial communities were investigated following exposure to uranium (U), a representative radioactive heavy metal. The results showed that 90-d of U exposure at environmentally relevant concentrations of 0.05 mg/L or 5 mg/L significantly increased the ARB concentration in activated sludge (p < 0.05). Furthermore, 90-d of U exposure slightly elevated the absolute abundance of aeARGs (except tetO) and sulfonamide iARGs, but decreased tetracycline iARGs. Regarding feARGs, the abundance of tetC, tetO, and sul1 decreased after 90-d of U stress, whereas sul2 showed the opposite trend. Partial least-squares path model analysis revealed that the abundance of aeARGs and iARGs under U stress was predominantly driven by increased cell membrane permeability/intI1 abundance and cell membrane permeability/reactive oxygen species concentration, respectively. Conversely, the changes in feARGs abundance depended on the composition of the microbial community and the expression of efflux pumps. Our findings shed light on the variations of ARGs and ARB in activated sludge under U exposure, providing a more comprehensive understanding of antibiotic resistance risks aggravated by radioactive heavy metal-containing wastewater.

Electroacupuncture targeting the immune system to alleviate sepsis

Sepsis is a life-threatening inflammatory syndrome with high morbidity and mortality rates. However, options for sepsis are still limited to general treatment in intensive care units (ICUs), and effective therapies that improve sepsis survival are required. Immune disturbances play a vital role in the pathology of sepsis and are associated with protracted inflammation, susceptibility to infections, and death. Therefore, many investigators have focused on the potential benefits of immunomodulation therapy for sepsis. Electroacupuncture (EA) has been practiced in clinics for many years and has shown advantages in treating infectious diseases. Over the last few decades, our understanding of the efficacy and mechanisms of EA in sepsis has undergone considerable developments. We searched the literature regarding “CNKI, Wan Fang Data, VIP Database, PubMed, and Ingenta Connect” from 2010 to 2023, using the keywords “sepsis” “septic” and “electroacupuncture” and 336 sources were searched. Finally, we included 82 studies that targeted the immune system to determine EA’s anti-inflammatory and immunomodulatory effects on sepsis. In this review, we found that EA has clinical benefits in relieving septic inflammation, improving immune function, and attenuating related multi-organ injury through several mechanisms, such as activation of the cholinergic anti-inflammatory pathway (CAP), vagal-adrenal axis, inhibition of the nuclear factor Kappa-B (NF-κB) signaling pathway, signal transducers and activators of transcription (STAT) signaling pathway, and improvement of immune cell function. Therefore, EA may be a promising complementary therapy for sepsis treatment. We also expect these data will contribute to further studies on EA in sepsis.

Evolution of Legislation Regarding the Use of Nuclear Energy for Peaceful Purposes

The development and use of atomic energy represent one of the greatest achievements of the 20th century, opening new possibilities for global evolution. The United Nations (UN) has formulated the «Millennium Development Goals» and the «Sustainable Development Goals by 2030» to address comprehensive solutions to the social, economic, and environmental challenges facing the planet. In this context, nuclear energy offers unparalleled advantages, but it is essential to consider the risks and challenges associated with its future use and development. Nuclear law serves as a valuable tool for regulating the development of nuclear energy and overcoming these risks and challenges. All countries must strictly fulfill their international obligations, responsibly implement international legal instructions at the national level, and collectively support the international regime and legal framework organized around the United Nations. This, in turn, contributes to the achievement of the shared goal of «atoms for peace and development».&#x0D; The international legal framework on nuclear issues emerged alongside the development of nuclear energy worldwide. It evolves as social, economic, scientific, and technical challenges associated with this development are addressed, thereby contributing to the safe, secure, and sustainable development of peaceful nuclear energy use.&#x0D; The IAEA and the international community have established an almost universal regime of safeguards aimed at detecting and preventing the diversion of nuclear materials from peaceful nuclear activities to the production of nuclear weapons.&#x0D; Based on the results of the conducted research, it has been established that each country not only has the right to use nuclear energy for peaceful purposes but also bears the responsibility and obligation to prevent the proliferation of nuclear weapons and to support nuclear safety and security. All countries should conscientiously fulfill their obligations in accordance with the international legal framework on nuclear safety, fully implement relevant resolutions of the United Nations Security Council, strengthen and expand the existing international legal framework on nuclear safety, and provide institutional guarantees, adhering to universally defined guiding principles for managing international nuclear safety.

ZC3H12A inhibits tumor growth and metastasis of breast cancer under hypoxic condition via the inactivation of IL-17 signaling pathway

ABSTRACT Hypoxia is a major contributor to tumor microenvironment (TME) and metastasis in most solid tumors. We seek to screen hypoxia-related genes affecting metastasis in breast cancer and to reveal relative potential regulatory pathway. Based on gene expression profiling of GSE17188 dataset, differential expressed genes (DEGs) were identified between highly metastatic breast cancer cells under hypoxia and samples under normoxia. The protein–protein interaction (PPI) network was utilized to determine hub genes. The gene expression profiling interactive analysis database (GEPIA2) and quantitative reverse-transcription polymerase chain reaction (qRT-PCR) were employed to quantify hub genes. Moreover, overexpression of zinc finger CCCH-type containing 12A (ZC3H12A) was performed both in breast cancer cells and xenograft mouse model to determine the role of ZC3H12A. We identified 134 DEGs between hypoxic and normoxic samples. Based on PPI analysis, 5 hub genes interleukin (IL)-6, GALN (GAL), CD22 molecule (CD22), ZC3H12A and TNF receptor associated factor 1 (TRAF1) were determined; the expression levels of TRAF1, IL-6, ZC3H12A and GAL were remarkably downregulated while CD22 was upregulated in breast cancer cells. Besides, patients with higher expression of ZC3H12A had favorable prognosis. Overexpression of ZC3H12A could inhibit metastasis and tumor growth of breast cancer; overexpression of ZC3H12A downregulated the expression of IL-17 signaling pathway-related proteins such as IL-17 receptor A (IL-17RA), IL-17A and nuclear factor κB activator 1 (Act1). This study reveals ZC3H12A and IL-17 signaling pathway as potential therapeutic targets for hypoxic breast cancer.

Targeted therapies for breast and lung cancers by using Propolis loaded albumin protein nanoparticles

BackgroundCancer is a popular disease among many others that can threaten human life. This is not only because of its invasiveness but also because of its resistance and the highly effective cost of its treatments. Propolis is rich in natural bioactive and polyphenolic compounds that have proven their strong effect on cancer cells such as MCF-7 and A549 cell lines. MethodsPropolis extract was immobilized into the bovine serum albumin (BSA) conjugated to folic acid (FA), to increase control of its delivery and to strengthen its cellular uptake. ResultsThe growth of MCF-7 was significantly decreased by propolis extract and BSA-propolis NPs after their incubation for 48 and 72 h by (54 ± 0.01 %, and 45 ± 0.005 %, P ≤ 0.001) and (20 ± 0.01 % and 10 ± 0.005 %, P ≤ 0.0001), respectively. Similarly, there is a significant inhibition in the growth of A549 obtained after their incubation with (propolis extract and albumin-propolis NPs) for 72 h (15 ± 0.03 % and 5 ± 0.01 %, P ≤ 0.00001). Propolis extract and BSA-propolis NPs exhibited a greater effect on protein expression of MCF-7 and A549, showing significant modulation of caspase-3, cyclin D1, and light chain 3 (LC3II). The result was supported by nuclear fragmentations and activation of acidic/neutral autophagosomes in acridine orange/ethidium bromide (AO/EB) and 4′,6-diamidino-2-phenylindole (DAPI) nuclear stains. According to this study, the expression of phospho-GSK3β (Ser9) (p < 0.001) increased significantly in MCF-7 and A549 cells after their exposure to propolis extract and BSA-propolis NPs. ConclusionResults support the potency application of propolis and its encapsulation as an alternative therapeutic agent for cancer treatments instead of chemotherapies because of its action on multi-signaling pathways.

Abstract B017: VCP extracts the chromatin remodeler SNF2H from nascent DNA to stabilize stressed replication forks

Abstract Valosin-containing protein (VCP) is an evolutionarily conserved AAA+ ATPase which plays pleiotropic roles in global proteostasis by extracting polyubiquitinated proteins from various cellular organelles and structures and facilitating their turnover. Our recent work demonstrated that nuclear VCP activity during DNA damage response specifically depends on ATM/ATR/DNA-PK-mediated Ser784 phosphorylation. Ser784phosphorylation increases VCP ability to facilitate chromatin-associated protein degradation and is required for DNA repair, checkpoint signaling, and cell survival. Clinically, high nuclear pSer784-VCP levels are significantly associated with poor survival outcome among chemotherapy-treated breast and pancreatic cancer patients. Thus, pSer784-VCP is a broadly important and therapeutically relevant genome stabilizer. Here, we focused specifically on the role of pSer784-VCP in DNA replication fork stability during stress, a known source of DNA damage if not properly regulated. By performing single-molecule DNA fiber analysis using human cell lines with genetic gain and loss-of-function of VCP, we observed that VCP protects nascent DNA from hydroxyurea (HU)-induced over-resection and this activity requires Ser784 phosphorylation. Using proximity ligation assay (PLA), we detected HU-induced pSer784-VCP on nascent DNA, suggesting that it may protect stressed forks by extracting functionally important regulators. Consistent with this theory, we detected an interaction of pSer784-VCP with SNF2H, a nucleosome-sliding enzyme which we recently found essential for nascent DNA over-resection at unprotected forks. In support of the hypothesis that SNF2H is a novel substrate of pSer784-VCP at stressed forks, we observed SNF2H retention on nascent DNA upon VCP knockdown in HU-treated cells, and the functional rescue of SNF2H retention by VCP re-expression requires Ser784phosphorylation. In support of their epistatic relationship, SNF2H depletion fully rescued fork over-resection caused by VCP loss. Similarly, blocking fork reversal by depleting SMARCAL1 or FBH1 also rescued fork over-resection caused by VCP loss. Importantly, mutating the ATPase activity of SNF2H abolished its ability to promote fork over-resection, suggesting that nucleosome remodeling by SNF2H underlies its effect on fork stability and may be a key molecular event enabling fork reversal upstream of fork degradation. Collectively, our data suggest that pSer784-VCP is a previously unrecognized stabilizer of stressed DNA replication forks, and it does so at least in part via its physical extraction of SNF2H from nascent DNA and the consequent attenuation of nucleosome remodeling needed for fork reversal and over-resection. More experiments are currently underway to further dissect the mechanistic aspects of this working model as well as to evaluate the potential of developing pSer784-VCP into a clinically relevant chemo-predictive biomarker and chemo-sensitizing target for different types of cancer. Citation Format: Jieya Shao, Mari Iwase, Rong Xu, Shuyang Lin. VCP extracts the chromatin remodeler SNF2H from nascent DNA to stabilize stressed replication forks [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: DNA Damage Repair: From Basic Science to Future Clinical Application; 2024 Jan 9-11; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2024;84(1 Suppl):Abstract nr B017.

African Nuclear Educational Network (AFRA-NEST): Assessment, challenges, and the way forward

As eleven African countries are planning or moving ahead with the implementation of national nuclear programs, the role of nuclear education networks in preparing the needed national workforce cannot be underestimated. A 2022 IAEA publication on Nuclear Educational Networks benchmarked the different nuclear networks. It suffices to mention that; as of 2022; the African Nuclear Educational Network, AFRA-NEST, does not have a network platform and the position of the regional coordinator is vacant. Also, the network did not witness any major activities since nearly 2013. This opinion paper is an attempt to better understand the history and status of AFRA-NEST, address the challenges and provide some recommendations on re-activating it to cope with the ongoing nuclear activities in Africa.

Metabolic effects of nuclear receptor activation in vivo after 28-day oral exposure to three endocrine-disrupting chemicals

Environmental exposure to endocrine-disrupting chemicals (EDCs) can lead to metabolic disruption, resulting in metabolic complications including adiposity, dyslipidemia, hepatic lipid accumulation, and glucose intolerance. Hepatic nuclear receptor activation is one of the mechanisms mediating metabolic effects of EDCs. Here, we investigated the potential to use a repeated dose 28-day oral toxicity test for identification of EDCs with metabolic endpoints. Bisphenol A (BPA), pregnenolone-16α-carbonitrile (PCN), and perfluorooctanoic acid (PFOA) were used as reference compounds. Male and female wild-type C57BL/6 mice were orally exposed to 5, 50, and 500 μg/kg of BPA, 1000, 10 000, and 100 000 µg/kg of PCN and 50 and 300 μg/kg of PFOA for 28 days next to normal chow diet. Primary endpoints were glucose tolerance, hepatic lipid accumulation, and plasma lipids. After 28-day exposure, no changes in body weight and glucose tolerance were observed in BPA-, PCN-, or PFOA-treated males or females. PCN and PFOA at the highest dose in both sexes and BPA at the middle and high dose in males increased relative liver weight. PFOA reduced plasma triglycerides in males and females, and increased hepatic triglyceride content in males. PCN and PFOA induced hepatic expression of typical pregnane X receptor (PXR) and peroxisome proliferator-activated receptor (PPAR)α target genes, respectively. Exposure to BPA resulted in limited gene expression changes. In conclusion, the observed changes on metabolic health parameters were modest, suggesting that a standard repeated dose 28-day oral toxicity test is not a sensitive method for the detection of the metabolic effect of EDCs.

Nuclear DNA damage-triggered ATM-dependent AMPK activation regulates the mitochondrial radiation response

Purpose AMP-activated protein kinase (AMPK) acts as a cellular energy sensor and is essential for controlling mitochondrial homeostasis. Here, we investigated the regulatory mechanisms involved in AMPK activation to elucidate how networks of intracellular signaling pathways respond to stress conditions. Materials and methods Inhibitors of ATM, DNA-PK, and AKT were tested in normal TIG-3 and MRC-5 human fibroblasts to determine which upstream kinases are responsible for AMPK activation. SV40 transformed-human ATM-deficient fibroblasts (AT5BIVA) and their ATM-complemented cells (i.e., AT5BIVA/ATMwt) were also used. Protein expression associated with AMPK signaling was examined by immunostaining and/or Western blotting. Results Radiation-induced nuclear DNA damage activates ATM-dependent AMPK signaling pathways that regulate mitochondrial quality control. In contrast, hypoxia and glucose starvation caused ATP depletion and activated AMPK via a pathway independent of ATM. DNA-PK and AKT are not involved in AMPK-mediated mitochondrial signaling pathways. Conclusion Activation of the AMPK signaling pathway differs depending on the stimulus. Radiation activates AMPK through two pathways: depletion of ATP-mediated LKB1 signaling and nuclear DNA damage-induced ATM signaling. Nuclear DNA damage signaling to mitochondria therefore plays a pivotal role in determining the cell fates of irradiated cells.

Changes of Nuclear Factor Kappa-B Pathway Activity in Hippocampus After Acute Carbon Monoxide Poisoning and Its Role in Nerve Cell Injury.

Acute carbon monoxide poisoning (ACOP) causes tissue hypoxia and damage mainly by binding to hemoglobin (Hb). This article aimed to explore the changes in the activity of nuclear factor kappa-B (NF-κB) pathway in the hippocampus after ACOP and its role in nerve cell damage. This article used 30 Sprague-Dawley (SD) rats as the research object, which were randomly divided into two groups, ACOP group and controls. The model of carbon monoxide (CO) poisoning was established, and then the activity of NF-κB pathway in the hippocampus of the two groups of rats was detected, and the statistical analysis was performed. Compared with the controls, the activity of NF-κB pathway in the hippocampus of the ACOP group was significantly increased (P < 0.05). The degree of neuronal damage in the ACOP group was also significantly increased. ACOP increases the activity of the NF-κB pathway in the hippocampus and may cause neuronal damage through this pathway. This provides new ideas and methods for the treatment of ACOP, and also provides new evidence for the role of NF-κB pathway in neuronal injury.

Nuclear-free NYC: How New Yorkers are disarming the legacies of the Manhattan Project

ABSTRACT In 2021, New York City passed some of the most progressive nuclear disarmament legislation of any major city in the United States, supported by local activists from the New York Campaign to Abolish Nuclear Weapons (NYCAN). In this essay, two of the people behind this effort share some details of their success with local government as an example of what others can do to bring nuclear abolitionist activism home. They also give a sense of New York’s long history as a nuclear city—and as a locus of action for disarmament.

Quantifying Safeguards Innovations: Impacts of Innovations on International Atomic Energy Agency Safeguards Inspection Effort

ABSTRACT The scope and breadth of nuclear safeguards activities are expanding as new nuclear facilities begin operations and countries sign new or extended safeguards agreements. The International Atomic Energy Agency (IAEA) has adopted technical and policy innovations to meet these increasing safeguards demands within their constrained resources. This study analyzes prominent safeguards innovations to determine their impact on safeguards inspection effort, measured in person-days of inspection. The most significant impact on inspection effort resulted from optimized safeguards measures called Integrated Safeguards, which are implemented in states for which the IAEA has concluded that all nuclear materials remain in peaceful uses (known as the “broader conclusion”). The impact of Integrated Safeguards on inspection effort could justify striving for broader conclusions for more states.