Stress-induced Activation Research Articles

Abstract 3606: HDAC8-mediated inhibition of EP300 drives a neural crest-like transcriptional state that increases melanoma brain metastasis

Abstract Melanomas are heterogeneous and adopt multiple transcriptional states that can confer an invasive phenotype and resistance to therapy. Little is known about the epigenetic drivers of these cell states, limiting our ability to regulate melanoma heterogeneity and tumor progression. Here we identify stress-induced HDAC8 activity as the driver of a neural crest stem cell (NCSC)-like transcriptional state that increased the formation of melanoma brain metastases (MBM). Exposure of melanocytes and melanoma cells to multiple different stresses led to HDAC8 activation, a switch to a NCSC gene expression signature and the adoption of an amoeboid, invasive phenotype. This cell state enhanced the survival of melanoma cells under shear stress conditions and increased the formation of metastases in the brain. Single cell RNA-seq analyses showed that HDAC8 expression was correlated with the NCSC cell state in clinical MBM specimens. ATAC-Seq and ChIP-Seq analysis showed HDAC8 to alter chromatin structure by increasing H3K27ac and accessibility at c-Jun binding sites without changing global histone acetylation. The increased accessibility of Jun binding sites was paralleled by decreased H3K27ac and accessibility at MITF binding sites and loss of melanoma-lineage gene expression. Mass spectrometry-based acetylomics demonstrated that HDAC8 deacetylated the histone acetyltransferase (HAT) EP300 leading to its enzymatic inactivation. This, in turn, led to an increased binding of EP300 to Jun-transcriptional sites and decreased binding to MITF-transcriptional sites. Increased expression of EP300 decreased invasion and increased the sensitivity of melanoma cells to multiple stresses while inhibition of EP300 function increased invasion and resistance to stress. We identified HDAC8 as a novel mediator of transcriptional co-factor inactivation and chromatin accessibility that increases MBM development. Citation Format: Michael Emmons, Richard Bennett, Alberto Riva, Chao Zhang, Robert Macaulay, Daphne Dupéré-Richér, Bin Fang, John Koomen, Jiannong Li, Ann Chen, Edward Seto, Jonathan Licht, Keiran Smalley. HDAC8-mediated inhibition of EP300 drives a neural crest-like transcriptional state that increases melanoma brain metastasis. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3606.

Novel Antiplatelet Activity of Ginsenoside Re Through the Inhibition of High Shear Stress-Induced Platelet Aggregation.

Bleeding is one of the most serious side effects of antiplatelet drugs. Efforts have been made to find new antiplatelet agents without bleeding complications. Shear-induced platelet aggregation (SIPA) occurs only under pathological conditions and is a promising target for overcoming bleeding problems. This work demonstrates that the ginsenoside Re selectively inhibits platelet aggregation induced by high shear stress. Human platelets were exposed to high shear stress using microfluidic chip technology, and aggregation, activation, and phosphatidylserine (PS) exposure were measured. The Von Willebrand Ristocetin Cofactor (vWF:RCo) assay and western blot were used to evaluate the effect of the vWF-GPⅠb/PI3K/Akt signal pathway. The coagulation and bleeding risk were evaluated by measuring the coagulation parameters PT, APTT, TT, and thromboelastography. The 3-dimensional morphology of platelet aggregates was observed by a microscopic 3-dimensional imaging. Re was a potent inhibitor of SIPA, with an IC 50 of 0.071 mg/mL. It effectively blocked shear stress-induced platelet activation without any significant toxicity. It was highly selective against SIPA, effectively inhibiting vWF-GPIb and the downstream PI3K/Akt signaling pathway. Most importantly, Re did not affect normal blood coagulation and did not increase the risk of bleeding. In conclusion, Re inhibits platelet activation through the inhibition of the vWF-GPIb/PI3K/Akt pathway. Thus, it might be considered as a new antiplatelet drug in the prevention of thrombosis without increasing the risk of bleeding.

Dysregulation of Stress-Induced Translational Control by Porphyromonas gingivalis in Host Cells.

Porphyromonas gingivalis contributes to the chronic oral disease periodontitis, triggering the activation of host inflammatory responses, inducing cellular stresses such as oxidation. During stress, host cells can activate the Integrated Stress Response (ISR), a pathway which determines cellular fate, by either downregulating protein synthesis and initiating a stress-response gene expression program, or by initiating programmed cell death. Recent studies have implicated the ISR within both host antimicrobial defenses and the pathomechanism of certain microbes. In this study, using a combination of immunofluorescence confocal microscopy and immunoblotting, the molecular mechanisms by which P. gingivalis infection alters translation attenuation during oxidative stress-induced activation of the ISR in oral epithelial cells were investigated. P. gingivalis infection alone did not result in ISR activation. In contrast, infection coupled with stress caused differential stress granule formation and composition. Infection heightened stress-induced translational repression independently of core ISR mediators. Heightened translational repression during stress was observed with both P. gingivalis-conditioned media and outer membrane vesicles, implicating a secretory factor in this exacerbated translational repression. The effects of gingipain inhibitors and gingipain-deficient P. gingivalis mutants confirmed these pathogen-specific proteases as the effector of exacerbated translational repression. Gingipains are known to degrade the mammalian target of rapamycin (mTOR) and the findings of this study implicate the gingipain-mTOR axis as the effector of host translational dysregulation during stress.

Spoonbill positively regulates JNK signalling mediated apoptosis in Drosophila melanogaster

A-kinase anchoring protein (AKAP) comprises a family of scaffold proteins, which decides the subcellular localisation of a combination of signalling molecules. Spoonbill (Spoon) is a putative A-kinase anchoring protein in Drosophila. We have earlier reported that Spoon suppresses ribonuclear foci formed by trinucleotide repeat expanded transcripts associated with Spinocerebellar Ataxia 8 neurodegeneration in Drosophila. However, the role of Spoonbill in cellular signalling was unexplored. In this report, we have unravelled a novel function of Spoon protein in the regulation of the apoptotic pathway. The Drosophila TNFα homolog, Eiger, induces apoptosis via activation of the JNK pathway. We have shown here that Spoonbill is a positive regulator of the Eiger-induced JNK signalling. Further genetic interaction studies show that the spoon interacts with components of the JNK pathway, TGF-β activated kinase 1 (Tak1 - JNKKK), hemipterous (hep - JNKK) and basket (bsk - JNK). Interestingly, Spoonbill alone can also induce ectopic activation of the JNK pathway in a context-specific manner. To understand the molecular mechanism underlying Spoonbill-mediated modulation of the JNK pathway, the interaction between Spoon and Drosophila JNK was assessed. basket encodes the only known JNK in Drosophila. This serine/threonine-protein kinase phosphorylates Jra/Kay, which transcriptionally regulate downstream targets like Matrix metalloproteinase 1 (Mmp1), puckered (puc), and proapoptotic genes hid, reaper and grim. Interestingly, we found that Spoonbill colocalises and co-immunoprecipitates with the Basket protein in the developing photoreceptor neurons. Hence, we propose that Spoon plays a vital role in JNK-induced apoptosis. Furthermore, stress-induced JNK activation underlying Parkinson's Disease was also examined. In the Parkinson’s Drosophila model of neurodegeneration, depletion of Spoonbill leads to a partial reduction of JNK pathway activation, along with improvement in adult motor activity. These observations suggest that the putative scaffold protein Spoonbill is a functional and physical interacting partner of the Drosophila JNK protein, Basket. Spoon protein is localised on the outer mitochondrial membrane (OMM), which may perhaps provide a suitable subcellular niche for activation of Drosophila Basket protein by its kinases which induce apoptosis.

Caspase 3-specific cleavage of MEK1 suppresses ERK signaling and sensitizes cells to stress-induced apoptosis.

Proper regulation of apoptotic cell death is crucial for normal development and homeostasis in multicellular organisms and is achieved by the balance between pro-apoptotic processes, such as caspase activation, and pro-survival signaling, such as extracellular signal-regulated kinase (ERK) activation. However, the functional interplay between these opposing signaling pathways remains incompletely understood. Here, we identified MAPK/ERK kinase (MEK) 1, a central component of the ERK pathway, as a specific substrate for the executioner caspase-3. During apoptosis, MEK1 is cleaved at an evolutionarily conserved Asp282 residue in the kinase domain, thereby losing its catalytic activity. Gene knockout experiments showed that MEK1 cleavage was mediated by caspase-3, but not by the other executioner caspases, caspase-6 or -7. Following exposure of cells to osmotic stress, elevated ERK activity gradually decreased, and this was accompanied by increased cleavage of MEK1. In contrast, the expression of a caspase-uncleavable MEK1(D282N) mutant in cells maintained stress-induced ERK activity and thereby attenuated apoptotic cell death. Thus, caspase-3-mediated, proteolytic inhibition of MEK1 sensitizes cells to apoptosis by suppressing pro-survival ERK signaling. Furthermore, we found that a RASopathy-associated MEK1(Y130C) mutation prevented this caspase-3-mediated proteolytic inactivation of MEK1 and efficiently protected cells from stress-induced apoptosis. Our data reveal the functional crosstalk between ERK-mediated cell survival and caspase-mediated cell death pathways and suggest that its dysregulation by a disease-associated MEK1 mutation is at least partly involved in the pathophysiology of congenital RASopathies.

TOMM40 Genetic Variants Cause Neuroinflammation in Alzheimer's Disease.

Translocase of outer mitochondrial membrane 40 (TOMM40) is located in the outer membrane of mitochondria. TOMM40 is essential for protein import into mitochondria. TOMM40 genetic variants are believed to increase the risk of Alzheimer's disease (AD) in different populations. In this study, three exonic variants (rs772262361, rs157581, and rs11556505) and three intronic variants (rs157582, rs184017, and rs2075650) of the TOMM40 gene were identified from Taiwanese AD patients using next-generation sequencing. Associations between the three TOMM40 exonic variants and AD susceptibility were further evaluated in another AD cohort. Our results showed that rs157581 (c.339T > C, p.Phe113Leu, F113L) and rs11556505 (c.393C > T, p.Phe131Leu, F131L) were associated with an increased risk of AD. We further utilized cell models to examine the role of TOMM40 variation in mitochondrial dysfunction that causes microglial activation and neuroinflammation. When expressed in BV2 microglial cells, the AD-associated mutant (F113L) or (F131L) TOMM40 induced mitochondrial dysfunction and oxidative stress-induced activation of microglia and NLRP3 inflammasome. Pro-inflammatory TNF-α, IL-1β, and IL-6 released by mutant (F113L) or (F131L) TOMM40-activated BV2 microglial cells caused cell death of hippocampal neurons. Taiwanese AD patients carrying TOMM40 missense (F113L) or (F131L) variants displayed an increased plasma level of inflammatory cytokines IL-6, IL-18, IL-33, and COX-2. Our results provide evidence that TOMM40 exonic variants, including rs157581 (F113L) and rs11556505 (F131L), increase the AD risk of the Taiwanese population. Further studies suggest that AD-associated mutant (F113L) or (F131L) TOMM40 cause the neurotoxicity of hippocampal neurons by inducing the activation of microglia and NLRP3 inflammasome and the release of pro-inflammatory cytokines.

Roles of the Oxytocin Receptor (OXTR) in Human Diseases.

The oxytocin receptor (OXTR), encoded by the OXTR gene, is responsible for the signal transduction after binding its ligand, oxytocin. Although this signaling is primarily involved in controlling maternal behavior, it was demonstrated that OXTR also plays a role in the development of the nervous system. Therefore, it is not a surprise that both the ligand and the receptor are involved in the modulation of behaviors, especially those related to sexual, social, and stress-induced activities. As in the case of every regulatory system, any disturbances in the structures or functions of oxytocin and OXTR may lead to the development or modulation of various diseases related to the regulated functions, which in this case include either mental problems (autism, depression, schizophrenia, obsessive-compulsive disorders) or those related to the functioning of reproductive organs (endometriosis, uterine adenomyosis, premature birth). Nevertheless, OXTR abnormalities are also connected to other diseases, including cancer, cardiac disorders, osteoporosis, and obesity. Recent reports indicated that the changes in the levels of OXTR and the formation of its aggregates may influence the course of some inherited metabolic diseases, such as mucopolysaccharidoses. In this review, the involvement of OXTR dysfunctions and OXTR polymorphisms in the development of different diseases is summarized and discussed. The analysis of published results led us to suggest that changes in OXTR expression and OXTR abundance and activity are not specific to individual diseases, but rather they influence processes (mostly related to behavioral changes) that might modulate the course of various disorders. Moreover, a possible explanation of the discrepancies in the published results of effects of the OXTR gene polymorphisms and methylation on different diseases is proposed.

Isoproterenol-induced Upregulation of HPSE Accelerates Triple-negative Breast Cancer Cell Proliferation and Migration through Enhancing the Transcriptional Activity of HIF-1α.

Triple-negative breast cancer (TNBC) is considered to be the most malignant subtype of breast cancer (BC). Heparanase (HPSE) has been reported to contribute to tumor development, but its potential function in TNBC is not clear. The intention of this study was to investigate whether HPSE affects TNBC progression and to explore the possible mechanisms. Bioinformatics analyses were applied to analyze the expression of HPSE in TNBC samples and normal breast samples. The mRNA and protein levels of HPSE in TNBC cells were detected by RT-qPCR and western blot. Function assays, including CCK-8 assay, colony formation assay, transwell assay and wound healing assay, were conducted to validate the effects of HPSE silencing on TNBC cell proliferation and migration. Mechanism experiments were performed to explore the upstream molecular mechanism of HPSE in TNBC cells. Silencing of HPSE suppressed the proliferation and migration of TNBC cells. Moreover, hypoxia-inducible factor-1 alpha (HIF-1α) interacted with the HPSE promoter and promoted the transcription of HPSE. Isoproterenol (ISO), a pharmacological substitute for chronic stress-induced sympathetic activation, was proven to induce HIF-1α upregulation, so as to transcriptionally activate HPSE in TNBC cells. Furthermore, it manifested that ISO facilitated TNBC cell proliferation and migration in an HPSE-dependent way. HPSE activated by ISO-induced HIF-1α promoted TNBC cell proliferation and migration, which might offer a novel insight for TNBC treatment.

Phenylsulfonimide PPARα Antagonists Enhance Nrf2 Activation and Promote Oxidative Stress-Induced Apoptosis/Pyroptosis in MCF7 Breast Cancer Cells.

The NF-E2-related factor 2 transcription factor (Nrf2) orchestrates the basal and stress-inducible activation of a vast array of antioxidant genes. A high amount of reactive oxygen species (ROS) promotes carcinogenesis in cells with defective redox-sensitive signaling factors such as Nrf2. In breast cancer (BC), emerging evidence indicates that increased Nrf2 activity enhances cell metastatic potential. An interconnection between peroxisome proliferator-activated receptors (PPARs) and Nrf2 pathways in cancer has been shown. In this light, newly synthesized PPARα antagonists, namely IB42, IB44, and IB66, were tested in the BC cell line MCF7 in parallel with GW6471 as the reference compound. Our results show that the most promising compound of this phenylsulfonimide series (IB66) is able to decrease MCF7 proliferation by blocking cells at the G2/M checkpoint. The underlying mechanism has been investigated, disclosing a caspase 3/Akt-dependent apoptotic/pyroptotic pathway induced by the increased generation of oxidative stress. Moreover, the involvement of Nrf2 and COX2 in IB66-treated MCF7 cell response has been highlighted. The reported data lay the groundwork for the development of alternative targeted therapy involving the Nrf2/PPARα molecular axis, able to overcome BC cell chemoresistance and cause better clinical outcomes, promoting other forms of programmed cell death, such as pyroptosis.

Effects of acupuncture on regulating the hippocampal inflammatory response in rats exposed to post-traumatic stress disorder

Data from clinical and experimental studies have verified the efficacy and safety of acupuncture in the treatment of post-traumatic stress disorder (PTSD). However, the concrete mechanism has not been well elucidated. The stress-induced activation of inflammatory response is involved in the development and pathogenesis of PTSD. Here, we aimed to investigate the effects of acupuncture on regulating the hippocampal inflammatory response in rats exposed to PTSD. Forty male rats were randomly divided into control, model, acupuncture and sertraline group. Within 1 day after adaptive feeding, all rats were exposed to single prolonged stress (SPS), except for the rats in the control group. Rats in acupuncture group were exposed to acupuncture intervention at the acupoints of Baihui (GV20) and Yintang (GV29), 20 min once per day for 15 days. Rats in sertraline group were exposed to a suspension of sertraline and distilled water (0.2 mg/ml), once per day for 15 days continuously. Body weight and elevated plus maze experiment were detected at different time-points to evaluate the behavioral changes of rats. HE staining method was used to observe the basic pathological morphological changes in hippocampus. Immunofluorescence staining method was used to observe the activation of hippocampal microglia. The content of IL-6 and IL-1β in serum were detected by ELISA method. Compared with the control group, the body weight of rats in model group significantly decreased on 8 days, and the percentage of time in open arms and open arm entries decreased significantly on 15 days after SPS procedures, which indicated that SPS induced PTSD-like behavior in rats. Acupuncture exerted therapeutic effect. Simultaneously, the result of HE staining confirmed that SPS induced hippocampal morphological changes in SPS rats. Notably, acupuncture reversed the reduction and pathological injury to some extent. The results have also shown that acupuncture intervention effectively reversed the activated microglia of the hippocampus in rats. Moreover, the expression of IL-1β in serum was significantly decreased by acupuncture intervention. In summary, the present study demonstrated that the role of acupuncture in eliminating PTSD-like behavior might be connected with reversing the pathological process of the inflammatory response mediated by the activation of microglia induced by SPS.

Comparisons of stress-related neuronal activation induced by restraint in adult male rat offspring with prenatal exposure to buprenorphine, methadone, or morphine.

Prenatal opioid exposure may impede the development of adaptive responses to environmental stimuli by altering the stress-sensitive brain circuitry located at the paraventricular nucleus of the hypothalamus (PVH) and locus coeruleus (LC). Corticotropin-releasing factor (CRF) released from neurons in the PVH has emerged as a key molecule to initiate and integrate the stress response. Methadone (Meth) and buprenorphine (Bu) are two major types of synthetic opioid agonists for first-line medication-assisted treatment of opioid (e.g., morphine, Mor) use disorder in pregnant women. No studies have compared the detrimental effects of prenatal exposure to Meth versus Bu on the stress response of their offspring upon reaching adulthood. In this study, we aimed to compare stress-related neuronal activation in the PVH and LC induced by restraint (RST) stress in adult male rat offspring with prenatal exposure to the vehicle (Veh), Bu, Meth, or Mor. CFos-immunoreactive cells were used as an indicator for neuronal activation. We found that RST induced less neuronal activation in the Meth or Mor exposure groups compared with that in the Bu or Veh groups; no significant difference was detected between the Bu and Veh exposure groups. RST-induced neuronal activation was completely prevented by central administration of a CRF receptor antagonist (α-helical CRF9-41, 10 μg/3 μL) in all exposure groups, suggesting the crucial role of CRF in this stress response. In offspring without RST, central administration of CRF (0.5 μg/3 μL)-induced neuronal activation in the PVH and LC. CRF-induced neuronal activation was lessened in the Meth or Mor exposure groups compared with that in the Bu or Veh groups; no significant difference was detected between the Bu and Veh exposure groups. Moreover, RST- or CRF-induced neuronal activation in the Meth exposure group was comparable with that in the Mor exposure group. Further immunohistochemical analysis revealed that the Meth and Mor exposure groups displayed less CRF neurons in the PVH of offspring with or without RST compared with the Bu or Veh groups. Thus, stress-induced neuronal activation in the PVH and LC was well preserved in adult male rat offspring with prenatal exposure to Bu, but it was substantially lessened in those with prenatal exposure to Meth or Mor. Lowered neuronal activation found in the Meth or Mor exposure groups may be, at least in part, due to the reduction in the density of CRF neurons in the PVH.

Oncoprotein SET dynamically regulates cellular stress response through nucleocytoplasmic transport in breast cancer.

SETβ is the predominant isoform of oncoprotein SE translocation (SET) in various breast cancer cell lines. Interactome-transcriptome analysis has shown that SETβ is intimately associated with cellular stress response. Among various exogenous stimuli, formaldehyde (FA) causes distinct biological effects in a dose-dependent manner. In response to FA at different concentrations, SET dynamically shuttles between the nucleus and cytoplasm, performing diverse biofunctions to restore homeostasis. At a low concentration, FA acts as an epidermal growth factor (EGF) and activates the HER2 receptor and downstream signaling pathways in HER2+ breast cancer cells, resulting in enhanced cell proliferation. Nucleocytoplasmic transport of SETβ is controlled by the PI3K/PKCα/CK2α axis and depletion or blockade of the transport of SETβ suppresses EGF-induced activation of AKT and ERK. SETβ also inhibits not only stress-induced activation of p38 MAPK signaling pathway, but also assembly of stress granules by hindering formation of the G3BP1-RNA complex. Our findings suggest that SET functions as an important regulator which modulates cellular stress signaling pathways dynamically.

Secretome of Young Mesenchymal Stromal Cells Rejuvenates Aged Mesenchymal Stromal Cells by Normalizing Their Phenotype and Restoring Their Differentiation Profile.

During aging, the proliferation and differentiation ability of mesenchymal stem/stromal cells (MSCs) gets affected, and hence, aged MSCs are not preferred for regenerative purposes. Rapid identification of aging-associated changes within MSCs and the mechanistic pathways involved are necessary to determine optimal cell sources to treat musculoskeletal disorders in older patients. In the present study, we have identified a set of phenotypic markers, namely downregulated expression of CD90 and upregulated expression of CD45, as age-defining markers for the bone marrow-derived MSCs. We also show that these phenotypic changes in aged MSCs correlate with their aging-mediated differentiation defects. We find that oxidative stress signaling leading to the activation of nuclear factor kappa B (NF-κB) plays an essential role in altering the phenotype and differentiation ability of the aged MSCs. We further show that treatment of aged MSCs with the conditioned medium (CM) derived from young MSCs (young-CM) restored their phenotype and differentiation potential to the young-like by ameliorating activation of NF-κB signaling in them. Similar changes could also be achieved by using an inhibitor of NF-κB signaling, showing that oxidative stress-induced NF-κB activation is the causative factor in the aging of MSCs. Additionally, we show that treating young MSCs with hydrogen peroxide mimics all the aging-mediated changes in them, underscoring the involvement of oxidative stress in the aging of MSCs. Overall, our data suggest that the altered expression of CD90 and CD45 surface markers can be used as a primary screen to identify the onset of aging in the MSCs, which can be quickly reversed by their in vitro treatment with young-CM or NF-κB inhibitor. Our study also puts the phenotypic characterization of MSCs in a clinical perspective.

Research progress of Gan-Yu-Hua-Huo syndrome based on emotional stress-induced latent herpes simplex virus-1 reactivation

Gan-Yu-Hua-Huo syndrome(Live qi stagnation transforming into fire pattern) is one of the core contents of the theory of emotional diseases in traditional Chinese medicine(TCM). It is the key link of the pathogenesis change of emotion-related diseases and widely exists in the pathological process of various related diseases. However, due to the lack of animal models in line with the characteristics of TCM syndromes, the research on biomedical basis of Gan-Yu-Hua-Huo syndrome and study of Chinese medicines for soothing liver and purging fire have been restricted seriously. This study found that the pathological process of facial fire-heat symptoms of Gan-Yu-Hua-Huo syndrome was similar to the facial symptoms due to the emotional stress-induced latent herpes simplex virus-1(HSV-1) reactivation. Therefore, this study proposed that the emotional stress-induced latent HSV-1 activation be used to establish the animal model of Gan-Yu-Hua-Huo syndrome. In this study, the state-of-art literature in the field of Gan-Yu-Hua-Huo syndrome was summarized, and the experimental animal model of Gan-Yu-Hua-Huo syndrome was established from the perspective of emotional stress-induced latent HSV-1 reactivation to reveal the active substances, potential targets and pathways related to the pathological mechanism of the syndrome. This study was expected to provide reference and basis for the pharmacodynamic characterization of commonly used Chinese medicine for Gan-Yu-Hua-Huo syndrome in clinical practice.

P62SQSTM1 Affects Interacting Substrates MDM2, MDMX and Casein Kinase 1alpha to Yield Protection of Beta-Catenin Along with p53 Silencing for Refractory AML

Interventions targeting individual driver mutations in AML have not overcome resistant disease. Missing has been definition of a signal hub that integrates multiple oncogenic drivers for a composite pathway to resistance, where hub abundance determines signal(s) strength. We hypothesized that AML signal hub is p62SQSTM1, a nonmutant-active signal scaffolding for multiple pathways, including NFkB and MAPK (Moscat, Cell. 2016). Genetic epistasis in AML cell lines validated origin from P62 of such signals. Oxidative stress resistance pathways (OXPHOS) driven by p62SQSTM1 may also join with pathway(s) for leukemic progenitor replication, involving HOXA and beta-catenin within resistant AML's, but this has not been established. We sought merging pathways to OXPHOS-mediated resistance also serving to guard replicative potential through HOXA and beta-catenin. AMLs from patients were tested prior to treatment, and later failure, of induction chemotherapy, when given along with targeted agent (for cases with Flt3 mutation). Resistant AML blasts were found to have tandem overexpression of HOXAs and OXPHOS effectors p62SQSTM1, NRF2, NQO1 (NADPH oxidoreductase), BCL-2 ranging from 2-5-fold log10 relative quantity (RQ-Taqman) above chemo-sensitive core-binding factor AML, which lacks HOXA expression. We hypothesized that disrupting the downstream pathway from p62SQSTM1 to OXPHOS ending on MDM2 and/or MDMX (Todoric, Cancer Cell, 2017) is an approach to affect broad cell extinction. Indeed, besides destabilization/destruction of wild-type p53 affected by MDM2, the paralogue MDMX exists in an induced tripartite complex with CK1alpha (CK1) and p53, whose activity for restraining p53 and protecting beta-catenin from phosphorylation/inactivation is disrupted upon stress-induced CK1 activation (Huang, EMBOJ, 2020; Ueda, Cancer Cell, 2021), which we affected by using a proteasome inhibitor (PI). We found by immunoblotting AML blast lysates following PI treatment in vitro with Ixazomib, CK1 translocates to the nucleus and phosphorylation (S33,S37,T41,S45)/inactivation and cytoplasmic export of beta-catenin ensued, accompanying cell apoptosis, thus implicating MDMX inactivation resulting from PI. Primary p53-wild-type AML blasts or isogenic cell lines were treated in vitro with graded doses of the MDM2 inhibitors Pevonedistat (PEVO) or Siremadlin, either added alone, or in combination with Ixazomib at pharmacokinetically-achievable dose ranges typical in patients. Among high-risk primary AML blasts with Flt3ITD alone, or ITD along with NUP98-NSD1 or mDNMT3A, or Flt3neg with mutant EP300, or with PRDM16-SKI fusion as drivers, synergy/cooperativity was observed between MDM2 inhibitor and PI Ixazomib for inhibition of 3H-thymidine incorporation and visible apoptosis in vitro. Full characterization within PRDM16-SKI blasts by immunoblotting demonstrated expected posttranslational modification (PTM) on beta-catenin by PI, whereas distinct PTM for beta-catenin followed PEVO application, and the combination demonstrated further heterogeneity. Treatment of these blasts with Ixazomib or the combination with PEVO also led to induction of p53 in tandem with the destruction of MDM2/MDMX PTM isoforms and nuclear translocation of CK1. Strong upregulation/nuclear translocation of NRF2 resulted as part of the apoptotic pathway. To further discriminate the requirement for, and the nature of PTMs in the functional outcomes, FLAG-tagged (S33-A, S37-A,T41-A) mutant beta-catenin isoform, also lacking lysine ubiquitin target residues, was transfected in a lentiviral vector into p53-mutant K562 cells as host, and cells were compared to the same cells transfected with non-mutant FLAG-tagged beta-catenin. PEVO/Ixazomib did not induce PTM in mutant FLAG-beta-catenin transfectants, but the expected PTMs occurred in wild-type FLAG-tagged beta-catenin transfectants. In this context, PEVO became a stimulator of cell proliferation of the cells bearing mutant PTM-resistant beta-catenin, thus implicating beta-catenin disruption involving these residues as a requisite for optimal AML cell inhibition with the combination. In addition, a combination of PEVO/Ixazomib was as effective for apoptosis as was Flt3 inhibitor among certain Flt3mutant primary AML blasts. A clinical test of this strategy is warranted in high-risk relapsed/refractory p53WT/p62SQSTM1-expressing AML.

Endoplasmic reticulum stress-activated nuclear factor-kappa B signaling pathway induces the upregulation of cardiomyocyte dopamine D1 receptor in heart failure

Dopamine D1 receptor (D1R), coded by the Drd1 gene, is induced in cardiomyocytes of failing hearts, triggering heart failure-associated ventricular arrhythmia, and therefore could be a potential therapeutic target for chronic heart failure. The regulation of D1R expression, however, is not fully understood. Here, we explored the molecular mechanism by which cardiomyocyte D1R is induced in failing hearts. We performed motif analysis for the promoter region of the Drd1 gene using the transcription factor affinity prediction (TRAP) method and identified nuclear factor-kappa B (NF-κB) as a candidate transcriptional factor regulating the expression of the Drd1 gene. We next employed murine models of heart failure from chronic pressure overload by transverse aortic constriction (TAC), and assessed myocardial Drd1 expression levels and NF-κB activity, as well as endoplasmic reticulum (ER) stress, which has been implicated in the pathogenesis of heart failure. Drd1 induction in TAC hearts was dependent on the severity of heart failure, and was associated with NF-κB activation and ER stress, as assessed by p65 phosphorylation and the expression of ER stress-related genes, respectively. We further tested if Drd1 was induced by ER stress via NF-κB activation in cultured neonatal rat ventricular myocytes. Tunicamycin activated NF-κB pathway in an ER stress-dependent manner and increased Drd1 expression. Importantly, inhibition of NF-κB pathway by pretreatment with Bay11-7082 completely suppressed the tunicamycin-induced upregulation of Drd1, suggesting that NF-κB activation is essential to this regulation. Our study demonstrates the pivotal role for the ER stress-induced NF-κB activation in the induction of D1R in cardiomyocytes. Intervention of this pathway might be a potential new therapeutic strategy for heart failure-associated ventricular arrhythmia.

Abstract 13155: Apelin and Apela for Therapy of Myocardial Fibrosis and Heart Failure

The apelin/apela – apelin receptor system regulates a variety of physiological cardiovascular functions including vascular tone, cardiac contractility, angiogenesis, and energy metabolism. However, the cell type specific effects of apelin/apela in the cardiovascular system are not well understood. The aim of this study was to investigate the potential role of apelin and apela in regulating development of myocardial fibrosis and to identify the signaling mechanisms underlying the anti-fibrotic effects. To investigate the role of apelin and apela in vivo , 2-month-old C57BL/6N male mice were injected with AAV9.LacZ, AAV9.Apelin or AAV9.Apela and subjected to thoracic aortic constriction (TAC) for 6 weeks. Echocardiography analysis at the end of the study showed that overexpression of either apelin or apela attenuated TAC-induced left ventricular (LV) dysfunction and increase in LV mass. Analysis of cardiac tissue showed downregulation of collagen I and fibrosis related periostin mRNA expression levels and reduced accumulation of interstitial fibrosis in the left ventricles of mice overexpressing apelin or apela. Studies in human cardiac fibroblasts in vitro showed that apelin and apela attenuate TGFβ1-induced collagen expression and secretion. Analyses of LV tissue and human fibroblast samples indicated that apelin and apela regulate the stress-induced activation of MAPK pathways. Chemical inhibitors and genetic modification of specific signaling elements identified p38 MAPK as a central signaling pathway mediating the inhibitory effect of apelin and apela on TGFβ1 signaling and TGFβ1-induced collagen production. In summary, we show that apelin and apela attenuate hemodynamic pressure overload -induced LV dysfunction and myocardial fibrosis and identify a novel signaling mechanism regulating the response. Our data suggests that activation of apelinergic signaling could offer a novel therapeutic approach to prevent the development of cardiac fibrosis and heart failure.

Sex-specific alterations in corticotropin-releasing factor regulation of coerulear-cortical network activity

The locus coeruleus (LC)-norepinephrine system is a stress responsive system that regulates arousal and cognitive functions through extensive projections, including to the prefrontal cortex. LC-cortical circuits are activated by stressors, and this activation is thought to contribute to stress-induced impairments in executive function. Because corticotropin-releasing factor (CRF) is a mediator of stress-induced LC activation, we examined the effects of CRF administered into the LC of male and female rats on network activity of two functionally distinct regions of the PFC, the medial PFC (mPFC) and the orbitofrontal cortex (OFC). Network activity, measured as local field potentials, was recorded in awake animals before and after intra-LC infusion of aCSF or CRF (2 or 20 ng). CRF had qualitatively distinct effects on network activity in males and females with respect to dose, region and timecourse. CRF (20 ng) produced a prominent theta oscillation (7–9 Hz) selectively in female rats shortly after LC infusion and 20 min later. In contrast, in male rats, CRF (2 and 20 ng) decreased the amplitude of power in the 4–6 Hz range in the mPFC 10 min after injection. Lastly, CRF (20 ng) increased mPFC-OFC coherence in females and decreased mPFC-OFC coherence in males. In sum, these results show sex differences in CRF modulation of the LC-norepinephrine system that regulates prefrontal cortical networks, which may underlie sex differences in cognitive and behavioral responses to stress.

Effects of N-acetyl-l-cysteine on chronic heat stress-induced oxidative stress and inflammation in the ovaries of growing pullets

The aims of this study were to investigate the effects of supplemental N-acetyl-l-cysteine (NAC) on chronic heat stress-induced oxidative stress and inflammation in the ovaries of growing pullets. A total of 120, 12-wk-old, Hy-Line Brown hens were randomly separated into 4 groups with 6 replicates of 5 birds in each group for 21 d. The 4 treatments were as follows: the CON group and CN group were supplemented with basal diet or basal diet with 1 g/kg NAC, respectively; and the HS group and HSN group were heat-stressed groups supplemented with basal diet or basal diet with 1 g/kg NAC, respectively. The results indicated that the ovaries suffered pathological damage due to chronic heat stress and that NAC effectively ameliorated these changes. Compared with the HS group, antioxidant enzyme activities (including SOD, GSH-Px, CAT, and T-AOC) were enhanced, while the MDA contents and the expression levels of HSP70 were decreased in the HSN group. In addition, NAC upregulated the expression levels of HO-1, SOD2, and GST by upregulating the activity of Nrf2 at different time points to mitigate oxidative stress caused by heat exposure. Simultaneously, NAC attenuated chronic heat stress-induced NF-κB pathway activation and decreased the expression levels of the proinflammatory cytokines IL-8, IL-18, TNF-α, IKK-α, and IFN-γ. Cumulatively, our results indicated that NAC could ameliorate chronic heat stress-induced ovarian damage by upregulating the antioxidative capacity and reducing the secretion of proinflammatory cytokines.

Research status and trends of the diabetic cardiomyopathy in the past 10 years (2012-2021): A bibliometric analysis.

Diabetic cardiomyopathy is one of the most life-threatening diabetic complications. However, the previous studies only discuss a particular aspect or characteristic of DCM, the current state and trends were explored by limited research. We aimed to perform a systemically bibliometric study of DCM research progress status in the past decade, visualize the internal conceptual structure and potential associations, and further explore the prospective study trends. Articles related to DCM published from January 2012 to December 2021 were collected in the Web of Science core collection (WoSCC) database on June 24, 2022. We exported all bibliographic records, including titles, abstracts, keywords, authorship, institutions, addresses, publishing sources, references, citation times, and year of publication. In addition, the journal Impact Factor and Hirsch index were obtained from the Journal Citation Report. We conducted the data screening, statistical analysis, and visualization via the Bibliometrix R package. VOS viewer software was employed to generate the collaboration network map among countries and institutions for better performance in visualization. In total, 1,887 original research articles from 2012 to 2021 were identified. The number of annual publications rapidly increased from 107 to 278, and a drastic increase in citation times was observed in 2017-2019. As for global contributions, the United States was the most influential country with the highest international collaboration, while China was the most productive country. Professor Cai Lu was the most prolific author. Shandong University published the most articles. Cardiovascular Diabetology journal released the most DCM-related articles. "Metabolic Stress-induced Activation of FoxO1 Triggers Diabetic Cardiomyopathy in Mice" Battiprolu PK et al., J Clin Invest, 2012. was the most top-cited article regarding local citations. The top three keywords in terms of frequency were apoptosis, oxidative stress, and fibrosis. The analysis of future topic trends indicated that "Forkhead box protein O1," "Heart failure with preserved ejection fraction," "Dapagliflozin," "Thioredoxin," "Mitochondria dysfunction," "Glucose," "Pyroptosis," "Cardiac fibroblast" and "Long non-coding RNA" could be promising hotspots. This study provides meaningful insights into DCM, which is expected to assist cardiologists and endocrinologists in exploring frontiers and future research directions in the domain through a refined and concise summary.