Inflammatory Gene Transcription Research Articles

Hydrocortisone improves post-resuscitation myocardial dysfunction by inhibiting the NF-κB pathway.

Myocardial dysfunction is a major cause of early mortality after successful cardiopulmonary resuscitation (CPR) following cardiac arrest (CA). Following the return of spontaneous circulation, myocardial ischemia-reperfusion injury can activate the NF-κB pathway, leading to the transcription of inflammatory genes that impair myocardial function. While clinical studies show hydrocortisone (HC) improves outcomes in CA patients during CPR, its specific role in modulating the NF-κB pathway is unclear. In this study, we established an in vitro model by inducing hypoxia/reoxygenation (H/R) injury in H9C2 cardiomyocytes using Na2S2O4, followed by HC treatment. The results showed that HC treatment of H/R-injured cardiomyocytes promoted proliferation, inhibited apoptosis, and suppressed the NF-κB pathway, thereby reducing IL-6, IL-8, and TNF-α levels. Moreover, inhibition of the NF-κB pathway enhanced the proliferative capacity of H/R cardiomyocytes, decreased apoptosis rates, and reduced IL-6, IL-8, and TNF-α expression levels, with these effects being further amplified by HC treatment. These findings were further supported by in vivo experiments. In conclusion, our study suggests that HC may promote H/R cardiomyocyte proliferation, inhibit apoptosis, and alleviate inflammatory responses by suppressing the NF-κB pathway, providing new evidence to support its potential clinical application in CA management.

ANK Deficiency-Mediated Cytosolic Citrate Accumulation Promotes Aortic Aneurysm.

Disturbed metabolism and transport of citrate play significant roles in various pathologies. However, vascular citrate regulation and its potential role in aortic aneurysm (AA) development remain poorly understood. Untargeted metabolomics by mass spectrometry was applied to identify upregulated metabolites of the tricarboxylic acid cycle in AA tissues of mice. To investigate the role of citrate and its transporter ANK (progressive ankylosis protein) in AA development, vascular smooth muscle cell (VSMC)-specific Ank-knockout mice were used in both Ang II (angiotensin II)- and CaPO4-induced AA models. Citrate was abnormally increased in both human and murine aneurysmal tissues, which was associated with downregulation of ANK, a citrate membrane transporter, in VSMCs. The knockout of Ank in VSMCs promoted AA formation in both Ang II- and CaPO4-induced AA models, while its overexpression inhibited the development of aneurysms. Mechanistically, ANK deficiency in VSMCs caused abnormal cytosolic accumulation of citrate, which was cleaved into acetyl coenzyme A and thus intensified histone acetylation at H3K23, H3K27, and H4K5. Cleavage under target and tagmentation analysis further identified that ANK deficiency-induced histone acetylation activated the transcription of inflammatory genes in VSMCs and thus promoted a citrate-related proinflammatory VSMC phenotype during aneurysm diseases. Accordingly, suppressing citrate cleavage to acetyl coenzyme A downregulated inflammatory gene expression in VSMCs and restricted ANK deficiency-aggravated AA formation. Our studies define the pathogenic role of ANK deficiency-induced cytosolic citrate accumulation in AA pathogenesis and an undescribed citrate-related proinflammatory VSMC phenotype. Targeting ANK-mediated citrate transport may emerge as a novel diagnostic and therapeutic strategy in AA.

Topical Reconstituted High-Density Lipoproteins Elicit Anti-Inflammatory Effects in Diabetic Wounds.

Objective: Reconstituted high-density lipoproteins (rHDL) improve wound healing in diabetes. We aimed to determine if rHDL elicit anti-inflammatory effects in diabetic wounds, as a mechanism to explain their wound healing benefits. Approach: Diabetes was induced using streptozotocin in C57Bl6/J mice. Two full-thickness wounds were placed on the subflanks of diabetic and nondiabetic (ND) mice. Phosphate-buffered saline (PBS) or rHDL (50 µg/wound/day) were applied topically. Wound closure was assessed daily. Inflammatory gene transcripts were measured by qPCR and proteins by Western blotting and enzyme-linked immunosorbent assay in wounds collected at baseline, 24 h, and 3 days postwounding. Wound macrophages were assessed by flow cytometry 7 days postwounding. The fate of fluorescent 3,3-dioctadecyloxacarbocyanine, perchlorate (DiO)-labeled rHDL was tracked by flow cytometry, fluorescent imaging, and microscopy. Results: In diabetic mice, rHDL increased wound closure rates at days 6 (+288%, p < 0.01) and 7 (+639%, p < 0.0001) postwounding, compared with PBS controls. After 3 days, rHDL-treated diabetic wounds had lower Rela (-65%) and C-C motif chemokine ligand 2 (Ccl2) (-59%) mRNA levels and CCL2 protein (29%) than PBS controls, p < 0.05 for all. Wound macrophage content was higher in diabetic than ND wounds, but rHDL did not change macrophage content or polarity. DiO-rHDL were taken up by key wound cells including fibroblasts, macrophages, keratinocytes and endothelial cells, and retained in wounds for at least 48 h. Innovation: rHDL exerts anti-inflammatory effects in diabetic wounds early postwounding, which may contribute to its wound healing properties. Conclusion: The anti-inflammatory properties of rHDL in diabetic wounds present topical rHDL as a novel treatment option for improving healing in patients with diabetic foot ulcers.

Deficiency of NLRP3 protects cerebral pericytes and attenuates Alzheimer's pathology in tau-transgenic mice.

Activation of NLRP3-containing inflammasome, which is responsible for IL-1β maturation, has been shown to contribute to Alzheimer's disease (AD)-associated pathogenesis in both APP- and tau-transgenic mice. However, effects of NLRP3 on pericytes and subsequent cerebrovascular pathology in AD remain unknown. NLRP3-deficient and wild-type AD animal models were generated by crossing human P301S tau-transgenic mice and Nlrp3 knockout mice. AD-associated neuroinflammation, tauopathy, vasculature and pericyte coverage in the brain were investigated using immunohistological and molecular biological methods. To investigate how NLRP3 regulates pericyte activation and survival, pericytes from the brains of Nlrp3 knockout and wild-type mice were cultured, treated with IL-1β and H2O2 at different concentrations and analyzed by confocal microscopy and flow cytometry after staining with fluorescently labelled phalloidin, annexin-V and PDGFRβ antibody. Deficiency of NLRP3 (1) reduced Iba-1, GFAP and AT8 antibody-immunoreactive phosphorylated tau-positive cells, without significantly altering transcription of inflammatory genes, (2) preserved cerebral vasculature and pericyte coverage and up-regulated Osteopontin gene transcription, and (3) improved cognitive function in tau-transgenic mice. In cell culture, NLRP3 deficiency prevented pericyte apoptosis. Treatment with IL-1β or H2O2 increased the expression of PDGFRβ in NLRP3-deficient pericytes, but decreased it in NLRP3 wild-type pericytes in a dose-dependent manner. Inhibition of NLRP3 can promote pericyte survival, improve cerebrovascular function, and attenuate AD pathology in the brain of tau-transgenic mice. Our study supports NLRP3 as a novel therapeutic target for Alzheimer's patients.

The transcriptional repressor B cell lymphoma 6 regulates CXCR3 chemokine and human leukocyte antigen II expression in endothelial cells

Interferon gamma (IFN-γ) induces an endothelial proimmunogenic phenotype through the JAK/STAT1 pathway, which can shape the activation of alloreactive leukocytes in transplant rejection. In immune cells, the DNA-binding protein B cell lymphoma 6 (BCL6) controls the transcription of inflammatory genes. This study tested if BCL6 modulates IFN-γ-induced gene expression in endothelial cells. In vitro, BCL6 was IFN-γ-inducible in primary human endothelium, along with CXCR3 chemokines and human leukocyte antigen (HLA). BCL6, HLA II, and CXCL9 were also increased in human cardiac transplants during acute rejection. Knockdown of BCL6 augmented, whereas overexpression and BTB domain inhibitors (BCL6-BTBi) suppressed, HLA II and CXCR3 chemokine expression but not HLA I. Further, BCL6 had a greater effect on HLA-DR and DP but was less involved in regulating HLA-DQ expression. The effect correlated with BCL6 binding motifs in or near affected genes. The BCL6 DNA recognition sequence was highly similar to that of STAT1, and BTBi reduced STAT1’s transcriptional activity in vitro. Our results show for the first time that BCL6 selectively controls IFN-γ-induced endothelial gene expression, advancing our understanding of the endogenous mechanisms regulating donor immunogenicity.

Chromatin modifier Hmga2 promotes adult hematopoietic stem cell function and blood regeneration in stress conditions

The molecular mechanisms governing the response of hematopoietic stem cells (HSCs) to stress insults remain poorly defined. Here, we investigated effects of conditional knock-out or overexpression of Hmga2 (High mobility group AT-hook 2), a transcriptional activator of stem cell genes in fetal HSCs. While Hmga2 overexpression did not affect adult hematopoiesis under homeostasis, it accelerated HSC expansion in response to injection with 5-fluorouracil (5-FU) or in vitro treatment with TNF-α. In contrast, HSC and megakaryocyte progenitor cell numbers were decreased in Hmga2 KO animals. Transcription of inflammatory genes was repressed in Hmga2-overexpressing mice injected with 5-FU, and Hmga2 bound to distinct regions and chromatin accessibility was decreased in HSCs upon stress. Mechanistically, we found that casein kinase 2 (CK2) phosphorylates the Hmga2 acidic domain, promoting its access and binding to chromatin, transcription of anti-inflammatory target genes, and the expansion of HSCs under stress conditions. Notably, the identified stress-regulated Hmga2 gene signature is activated in hematopoietic stem progenitor cells of human myelodysplastic syndrome patients. In sum, these results reveal a TNF-α/CK2/phospho-Hmga2 axis controlling adult stress hematopoiesis.

Tai Chi compared with cognitive behavioral therapy and the reversal of systemic, cellular and genomic markers of inflammation in breast cancer survivors with insomnia: A randomized clinical trial

BackgroundInsomnia contributes to inflammation in breast cancer survivors. This study evaluates whether insomnia treatment reverses inflammation in breast cancer survivors with insomnia. MethodsParticipants (n = 90) were randomized to 3 months of Tai Chi (n = 45) or cognitive behavioral therapy for insomnia (CBT-I)(n = 45), and followed for one year post-intervention to 15 month endpoint. Our previous report found that Tai Chi as compared to CBT-I resulted in similar rates of insomnia response and remission over 15 months. Here, we analyze changes in plasma C-reactive protein and pro- and anti-inflammatory cytokines, Toll-like receptor (TLR)-4 stimulated monocyte production of interleukin (IL)-6 and tumor necrosis factor-α (TNF), and cellular pro-inflammatory and anti-viral gene expression (Conserved Transcriptional Response to Adversity RNA profile; CTRA) over 15 months. ResultsInsomnia treatment resulted in decreases in the TLR-4 stimulated monocyte production of IL-6, TNF, and their co-expression, as well as decreases in the CTRA profile, decreases inflammatory gene transcripts, and increases in anti-viral gene transcripts over 15 months (all P’s < 0.01). In addition, as compared to CBT-I, Tai Chi resulted in greater decreases in plasma IL-6 (P < 0.05), and greater decreases in TLR-4 activated monocyte production of IL-6 and co-expression of IL-6 and TNF at 15 month endpoint. CBT-I resulted in greater increases in anti-viral gene transcripts. ConclusionsAdministration of either CBT-I or Tai Chi effectively treats insomnia, and shows additional benefits of reducing cellular and genomic markers of inflammation, and increasing anti-viral genomic markers in breast cancer survivors with insomnia. Tai Chi, as compared to CBT-I, yields greater and more durable decreases in systemic- and cellular inflammation. Targeting insomnia might mitigate the risk of inflammation-related co-morbidities in breast cancer survivors.

N4BP1 coordinates ubiquitin-dependent crosstalk within the IκB kinase family to limit Toll-like receptor signaling and inflammation

The ubiquitin-binding endoribonuclease N4BP1 potently suppresses cytokine production by Toll-like receptors (TLRs) that signal through the adaptor MyD88 but is inactivated via caspase-8-mediated cleavage downstream of death receptors, TLR3, or TLR4. Here, we examined the mechanism whereby N4BP1 limits inflammatory responses. In macrophages, deletion of N4BP1 prolonged activation of inflammatory gene transcription at late time points after TRIF-independent TLR activation. Optimal suppression of inflammatory cytokines by N4BP1 depended on its ability to bind polyubiquitin chains, as macrophages and mice-bearing inactivating mutations in a ubiquitin-binding motif in N4BP1 displayed increased TLR-induced cytokine production. Deletion of the noncanonical IκB kinases (ncIKKs), Tbk1 and Ikke, or their adaptor Tank phenocopied N4bp1 deficiency and enhanced macrophage responses to TLR1/2, TLR7, or TLR9 stimulation. Mechanistically, N4BP1 acted in concert with the ncIKKs to limit the duration of canonical IκB kinase (IKKα/β) signaling. Thus, N4BP1 and the ncIKKs serve as an important checkpoint against over-exuberant innate immune responses.

Inflammatory Reprogramming Mediates Changes in Three-Dimensional Strain Capacity and Cardiac Function in Beagle Dogs with Doxorubicin-Related Cardiomyopathy.

The cardiotoxicity of doxorubicin (DOX) limits its use in cancer treatment. To address this limitation, we developed a novel animal model that uses beagle dogs to investigate DOX-induced cardiac disorders. Unfortunately, the lack of effective cardioprotection strategies against DOX-induced cardiotoxicity poses a significant challenge. To establish a canine model for low-mortality DOX-induced cardiac dysfunction and explore the relationship between inflammatory reprogramming and DOX-related cardiotoxicity. Twenty male beagle dogs aged two years were randomly assigned into the DOX (N = 10) and control (CON) (N = 10) groups. DOX was infused (1.5 mg/kg) every two weeks until doses cumulatively reached 12 mg/kg. Serum biomarkers and myocardial pathology were evaluated, while real-time fluorescence-based quantitative polymerase chain reaction (RTFQ-PCR), two- and three-dimensional echocardiography (2DE and RT3DE), functional enrichment, and matrix correlation were also performed. In the DOX group, high-sensitive cardiac troponin T (hs cTnT) and N-terminal pro-brain natriuretic peptide (NT-proBNP) were significantly increased. Myocardial pathology indicated early to medium myocardial degeneration via a decreased cardiomyocyte cross-sectional area (CSA). Increased levels of inflammatory gene transcripts (interleukin 6 (IL6), tumor necrosis factor (TNF), transforming growth factor (TGF ), intercellular adhesion molecule 1 (ICAM1), interleukin 1 (IL1), interleukin 1 (IL1 ), and interleukin 8 (IL8)), of collagen metabolism and deposition regulatory genes (matrix metalloproteinase (MMP) family and tissue inhibitor of matrix metalloproteinase (TIMP) family), and the natriuretic peptide family (NPS) (natriuretic peptide A, B and C (NPPA, NPPB, and NPPC)) were observed. Strain abnormalities in the right ventricular longitudinal septal strain (RVLSS), right ventricular longitudinal free-wall strain (RVLFS), left ventricular global longitudinal strain (LVGLS), and left ventricular global circumferential strain (LVGCS) were detected at week 28 (vs. week 0 or CON group, p 0.05, respectively). A significant decline in RVLSS and RVLFS occurred at week 16, which was earlier than in the corresponding left ventricular areas. A significant right ventricular ejection fraction (RVEF) decline was noted at week 16 (vs. week 0, 33.92 3.59% vs. 38.58 3.58%, p 0.05), which was 12 weeks earlier than for the left ventricular ejection fraction (LVEF), which occurred at week 28 (vs. week 0, 49.02 2.07% vs. 54.26 4.38%, p 0.01). The right ventricular strain and functional damages correlated stronger with inflammatory reprogramming (most R from 0.60 to 0.90) than the left ones (most R from 0.30 to 0.65), thereby indicating a more pronounced correlation. Inflammatory reprogramming mediated disorders of strain capacity and cardiac function predominantly in the right side of the heart in the newly established DOX-related cardiomyopathy beagle dog model.

A188 ENHANCED MICROBIAL TRYPTOPHAN METABOLISM ACTIVATES THE ARYL HYDROCARBON RECEPTOR AND AMELIORATES INTESTINAL INFLAMMATION

Abstract Background Intestinal microbiota, diet, and the immune system have been proposed to contribute to the development of inflammatory bowel diseases (IBD). The aryl hydrocarbon receptor (AhR) is a critical regulator of intestinal immunity and mucosal barrier homeostasis that is activated by agonists such as host and microbial tryptophan metabolites. IBD patients have altered microbiota and reduced AhR agonists in intestinal content resulting in downregulation of AhR. Our recent findings indicate that mice harbouring microbiota with impaired tryptophan metabolism and AhR agonist production develop more severe inflammation during colitis. Aims To study the influence of diet-microbe interventions on AhR activation and intestinal inflammation in mice with impaired microbial tryptophan metabolism. Methods Germ-free C57BL/6 mice from McMaster’s Axenic Gnotobiotic Unit were colonized with cecal content of mice harbouring reduced microbiota with impaired tryptophan metabolism with and without tryptophan metabolizing Clostridium sporogenes. Following three weeks of microbial stabilization, mice were provided a high tryptophan (HT) diet or a low tryptophan (LT) diet as a control. Experimental colitis was induced using dextran sulfate sodium in drinking water (DSS; 2.5% w/v). Briefly, DSS was provided ad libitum for five days, followed by two days of recovery before tissue collection. Activation of AhR was measured in stool and C. sporogenes cultures using an in vitro AhR luciferase reporter assay. AhR agonists were quantified by capillary-electrophoresis-mass spectrometry. Colonic expression of AhR pathway genes was evaluated by RT-qPCR. Susceptibility to colitis was assessed by histologic analysis of distal colon sections, fecal lipocalin-2, weight loss, and clinical scores. Inflammatory gene transcripts were quantified in colon tissue by Nanostring. Results C. sporogenes efficiently produces AhR agonists in vitro and in vivo. In mice with impaired tryptophan metabolism, the HT diet increased AhR agonists in intestinal content and colonic AhR pathway gene expression, which was further enhanced in mice colonized with C. sporogenes. Compared to mice fed LT and HT diets, mice colonized with C. sporogenes and fed HT were most protected from weight loss, tissue damage, and immune cell infiltration. Conclusions These findings highlight the potential of tryptophan-rich diets and targeted microbe interventions as a novel approach to enhance AhR activation and mitigate inflammation during colitis. Consequently, exploring methods to improve tryptophan metabolism through diet and manipulation of the microbiota could be a promising therapeutic avenue for IBD patients with impaired AhR activation. Funding Agencies CCC, CIHR

Topical Delivery of Tofacitinib in Dermatology: The Promise of a Novel Therapeutic Class Using Biodegradable Dendritic Polyglycerol Sulfates.

Inflammatory skin diseases, such as psoriasis, atopic dermatitis, and alopecia areata, occur when the regulatory tolerance of the innate immune system is disrupted, resulting in the activation of the Janus kinase-signal transducer and activator of transcription (JAK-STAT) inflammatory signaling pathway by interleukin 6 (IL-6) and other key inflammatory cytokines. JAK inhibitors, such as tofacitinib, bind to these enzymes which are coupled to receptors on cell surfaces and block the transcription of inflammatory cytokine-induced genes. The first topical applications are being marketed, yet insufficient effects regarding indications, such as alopecia areata, suggest that improved delivery technologies could help increase the efficacy. In this study, we used sulfated dendritic polyglycerol with caprolactone segments integrated in its backbone (dPGS-PCL), with a molecular weight of 54 kDa, as a degradable carrier to load and solubilize the hydrophobic drug tofacitinib (TFB). TFB loaded in dPGS-PCL (dPGS-PCL@TFB), at a 11 w/w% loading capacity in aqueous solution, showed in an ex-vivo human skin model better penetration than free TFB in a 30:70 (v/v) ethanol/water mixture. We also investigated the anti-inflammatory efficacy of dPGS-PCL@TFB (0.5 w/w%), dPGS-PCL, and free TFB in the water/ethanol mixture by measuring their effects on IL-6 and IL-8 release, and STAT3 and STAT5 activation in ex vivo skin models of simulated inflamed human skin. Our results suggest that dPGS-PCL@TFB reduces the activation of STAT3 and STAT5 by increasing the penetration of the tofacitinib. However, no statistically significant differences with respect to the inhibition of IL-6 and IL-8 were observed in this short incubation time.

Pyridaben induces apoptosis and inflammation in bovine mammary epithelial cells by disturbance of calcium homeostasis and upregulation of MAPK cascades

Pyridaben is a widely used pyridazinone insecticide used to protect crops against insects and mites. The toxicity of pyridaben has been reported in mice, zebrafish, the human reproductive system, nervous system, and respiratory system. Pyridaben can also be ingested by dairy cattle through feed. However, the toxicity of pyridaben in cattle has not been investigated on. Thus, this study focuses on demonstrating the toxicity of pyridaben in the bovine mammary glands and with the generation milk in the bovine mammary epithelial cells, as it is crucial to the continuance of the amount and the quality of the milk produced. We started by analyzing the intracellular toxicity along with the impact of pyridaben on the cell cycle distribution and the transcription of associated genes. Pyridaben treatment induced cell cycle arrest accompanied the disruption in G1 and S phases with imbalanced cytosolic and mitochondrial calcium ion homeostasis, and caused a destruction of mitochondrial membrane potential. This eventually led to apoptosis of MAC-T cells. We also investigated in the impact that pyridaben has on MAPK signaling proteins, where phosphorylation of ERK1/2, JNK, and p38 were upregulateed. Moreover, examination of the effect of pyridaben in the inflammatory genes revealed hyperactivation of the inflammatory gene transcription. This is the first research to assess the negative outcomes that pyridaben could impose on dairy cattle and milk production.

Exploratory Study on Impact of Comorbid Sleep Apnea Treatment in Patients with Polycythemia Vera and Essential Thrombocythemia

Background: Systemic inflammation has been implicated in the progression of myeloproliferative neoplasms (MPNs), polycythemia vera (PV) and essential thrombocythemia (ET). Obstructive sleep apnea (OSA) is a highly prevalent disorder that can lead to TNF-driven systemic inflammation. OSA leads to oxidative stress and NF-kB driven inflammatory gene expression through the mechanistic pathways of intermittent hypoxia and autonomic activation. We therefore sought to understand the prevalence of OSA in patients with MPNs and the feasibility of understanding the impact of treating comorbid sleep apnea in patients with PV and ET. Methods: Patients with PV and ET diagnosed using the 2008 or 2016 WHO criteria underwent STOP-BANG questionnaires to evaluate for the likelihood of OSA. Based on the finding of 3 or more positive responses on STOP-BANG questionnaire (PLoS One 2015;10:e0143697), patients underwent further evaluation with polysomnography or home sleep apnea test to diagnose OSA at an American Academy of Sleep Medicine-certified sleep laboratory (Figure 1). Patients with apnea-hypopnea index (AHI) of 5 or more events per hour and Eastern Cooperative Oncology Group scale score of 0-2 underwent continuous positive airway pressure therapy (CPAP). Effects of CPAP therapy on MPN-symptom assessment form total symptom scores (MPN-SAF TSS), JAK2V617F, MPL and CALR allelic burden, and exploratory endpoints of changes in inflammatory and thrombotic markers were ascertained (Figure 1). Comparisons with observational cohorts were planned to ascertain changes in the above endpoints at 0-, 3- and 6-months intervals (Figure 1). Based on a 40% reduction in allele burden (SD of 25%) and correlation of 0.5 between paired measurements, it was estimated that using a paired t-test with 27 evaluable patients will provide a 95% power to detect a 20% change in JAK2V617F burden from 40% to 20%. Similarly, assuming a 50% correlation (SD of 16) between pre- and post-therapy MPN-SAF TSS scores, 27 evaluable patients will provide a 80% power to detect a change of 10 at the two-sided 0.025 significance level. Results: Screening for OSA in patients with ET and PV revealed a high prevalence of OSA risk based on STOP-BANG scores. 26/29 males (mean age 63.6±11.8 years; BMI 29±3.3) and 16/26 females (mean age 61.5±12.8 years; BMI 28.2±6.5) had STOP-BANG scores of 3 or more. 8 patients with PV and ET have so far been enrolled into this study. 6/8 patients (age ranges from 41-74 years; 4 females and 2 males) with OSA (AHI 5-56 events/hr; 4% oxygen desaturation index 4.7-30/hr) underwent CPAP therapy. 1/6 patients in the CPAP arm did not tolerate CPAP and was excluded. 5/6 patients completed study procedures as did 2 additional patients without OSA in the observational study arm. Of 5/6 patients undertaking CPAP, 3/5 had the JAK2V617F mutations whereas 2/5 had the CALR mutation. JAK2V617F allele burdens at baseline in 2/5 patients were 80.7% and 4% at baseline and reduced to 73% and 1% at 6 months respectively whereas the third patient had undetectable JAK2V617F burdens throughout the study. All except one patient experienced improvement in MPN-SAF TSS scores after 6 months of CPAP therapy. While all 5 patients treated with CPAP showed improvements in C-reactive protein levels, analysis of NFkB1, TNF and IL-6 transcript levels showed mixed results. Similar mixed results were found with hypoxia-inducible factor (HIF) target gene expression ( SLC2A1, VEGF-A, EDN1) and markers of iron turnover (% transferrin saturation, transferrin, iron and ferritin levels) despite reduction in erythropoietin values in 4/5 patients with CPAP therapy at 6 months. Conclusions: Given the significant likelihood of OSA in patients with PV and ET (as based on STOP-BANG scores of 3 or more), there is need to evaluate and treat for OSA. Preliminary results show abnormalities in inflammatory markers with reductions in C-reactive protein and erythropoietin levels following CPAP therapy even though mixed results were noted in inflammatory and HIF-target gene transcripts, and markers of iron turnover. Larger studies and longer follow-up are required to understand the impact of OSA on not only the thrombotic and inflammatory milieu in patients with MPNs, but also the benefit of treating on prevention of disease progression and thrombotic manifestations common in MPNs. Funding: Huntsman Interventional Trial Grant CTO #HCI-17-HEM 28.

Site-selective synthesis and pharmacological elucidation of novel semi-synthetic analogues of koenimbine as a potential anti-inflammatory agent

Koenimbine (1), a carbazole alkaloid isolated from Murraya koenigii, belongs to the Rutaceae family. Various pharmacological effects such as anti-diabetic, melanogenesis inhibition, anti-diarrheal, anti-cancer, and anti-inflammatory properties of koenimbine have already been reported. In the current study, we investigated the anti-inflammatory role of koenimbine (1) and its novel semi-synthetic derivative 8-methoxy-3,3,5-trimethylpyrano[3,2-a] carbazole-11(3H)-yl) (3-(trifluoromethyl) phenyl) methanone (1G) in both in vitro and in vivo biological systems. Our results demonstrated that the anti-inflammatory activity of 1G significantly lowered the production of NO, pro-inflammatory cytokines (IL-6, TNF-α & IL-1β), LTB4 following LPS stimulation in RAW 264.7 macrophages. Furthermore, 1G significantly attenuated the expression levels of nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in a dose dependent manner and also decreased the production of reactive oxygen species (ROS) in LPS-activated RAW 264.7 cells. In addition, the oral administration of 1G reduced the inflammatory response in carrageenan-induced paw edema in BALB/C mice. Moreover, it effectively reduced NO, IL-6, IL-1β & TNF-α levels, liver markers (AST, ALT), and kidney markers (BUN, CRE, and Urea). Also, 1G reverted the infiltration of inflammatory cells and tissue damage in lungs, liver and kidney enhanced the survival rate in LPS-challenged mice. 1G blocks NF-κB p65 from translocating into the nucleus and activating inflammatory gene transcription. These results illustrated that 1G suppresses the inflammatory effects both in-vitro and in-vivo studies via downregulating the nuclear factor kappa-B (NF-κB) signaling pathway. In conclusion, our results demonstrate that semi-synthetic derivative 1G can effectively attenuate the inflammatory response via NF-κB and MAPK signaling pathways; suggesting 1G is a potential novel anti-inflammatory drug candidate in treating inflammatory disorders.

Critical Role of Novel O-GlcNAcylation of S550 and S551 on the p65 Subunit of NF-κB in Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies, with a mere 5-year survival of ~10%. This highlights the urgent need for innovative treatment options for PDAC patients. The nuclear factor κB (NF-κB) is a crucial transcription factor that is constitutively activated in PDAC. It mediates the transcription of oncogenic and inflammatory genes that facilitate multiple PDAC phenotypes. Thus, a better understanding of the mechanistic underpinnings of NF-κB activation holds great promise for PDAC diagnosis and effective therapeutics. Here, we report a novel finding that the p65 subunit of NF-κB is O-GlcNAcylated at serine 550 and 551 upon NF-κB activation. Importantly, the overexpression of either serine-to-alanine (S-A) single mutant (S550A or S551A) or double mutant (S550A/S551A) of p65 in PDAC cells impaired NF-κB nuclear translocation, p65 phosphorylation, and transcriptional activity, independent of IκBα degradation. Moreover, the p65 mutants downregulate a category of NF-κB-target genes, which play a role in perpetuating major cancer hallmarks. We further show that overexpression of the p65 mutants inhibited cellular proliferation, migration, and anchorage-independent growth of PDAC cells compared to WT-p65. Collectively, we discovered novel serine sites of p65 O-GlcNAcylation that drive NF-κB activation and PDAC phenotypes, thus opening new avenues by inhibiting the NF-κB O-GlcNAcylation enzyme, O-GlcNAc transferase (OGT), for PDAC treatment in the future.

ANGPTL3 negatively regulates IL-1β-induced NF-κB activation by inhibiting the IL1R1-associated signaling complex assembly.

Interleukin-1β (IL-1β)-induced signaling is one of the most important pathways in regulating inflammation and immunity. The assembly of the receptor complex, consisting of the ligand IL-1β, the IL-1 receptor (IL-1R) type 1 (IL1R1), and the IL-1R accessory protein (IL1RAP), initiates this signaling. However, how the IL1R1-associated complex is regulated remains elusive. Angiopoietin like 3 (ANGPTL3), a key inhibitor of plasma triglyceride clearance, is mainly expressed in the liver and exists in both intracellular and extracellular secreted forms. Currently, ANGPTL3 has emerged as a highly promising drug target for hypertriglyceridemia and associated cardiovascular diseases. However, most studies have focused on the secreted form of ANGPTL3, while its intracellular role is still largely unknown. Here, we report that intracellular ANGPTL3 acts as a negative regulator of IL-1β-triggered signaling. Overexpression of ANGPTL3 inhibited IL-1β-induced NF-κB activation and the transcription of inflammatory genes in HepG2, THP1, and HEK293T cells, while knockdown or knockout of ANGPTL3 resulted in opposite effects. Mechanistically, ANGPTL3 interacted with IL1R1 and IL1RAP through its intracellular C-terminal fibrinogen-like domain and disrupted the assembly of the IL1R1-associated complex. Taken together, our study reveals a novel role for ANGPTL3 in inflammation, whereby it inhibits the physiological interaction between IL1R1 and IL1RAP to maintain immune tolerance and homeostasis in the liver.

Kynurenine monooxygenase regulates inflammation during critical illness and recovery in experimental acute pancreatitis

Kynurenine monooxygenase (KMO) blockade protects against multiple organ failure caused by acute pancreatitis (AP), but the link between KMO and systemic inflammation has eluded discovery until now. Here, we show that the KMO product 3-hydroxykynurenine primes innate immune signaling to exacerbate systemic inflammation during experimental AP. We find a tissue-specific role for KMO, where mice lacking Kmo solely in hepatocytes have elevated plasma 3-hydroxykynurenine levels that prime inflammatory gene transcription. 3-Hydroxykynurenine synergizes with interleukin-1β to cause cellular apoptosis. Critically, mice with elevated 3-hydroxykynurenine succumb fatally earlier and more readily to experimental AP. Therapeutically, blockade with the highly selective KMO inhibitor GSK898 rescues the phenotype, reducing 3-hydroxykynurenine and protecting against critical illness and death. Together, our findings establish KMO and 3-hydroxykynurenine as regulators of inflammation and the innate immune response to sterile inflammation. During critical illness, excess morbidity and death from multiple organ failure can be rescued by systemic KMO blockade.

PQBP1 regulates the cellular inflammation induced by avian reovirus and interacts with the viral p17 protein

Avian reovirus (ARV) can commonly infect a flock and cause immunosuppressive diseases in poultry. The nonstructural protein p17 is involved in viral replication, and significant progress has been made in showing its ability to regulate cellular signaling pathways. In our previous study, to further investigate the effect of ARV p17 protein on viral replication, the host protein polyglu-tamine binding protein 1 (PQBP1) was identified to interact with p17 by a yeast two-hybrid system. In the current study, the interaction between PQBP1 and p17 protein was further confirmed by laser confocal microscopy and coimmunoprecipitation assays. In addition, the N-terminal WWD of PQBP1 was found to mediate the process of binding to the p17 protein. Interestingly, we found that ARV infection significantly inhibited PQBP1 expression. While the quantity of ARV replication was largely influenced by PQBP1, PQBP1 overexpression decreased ARV replication. In contrast, upon PQBP1 knockdown, the quantity of ARV was notably increased. ARV infection and p17 protein expression were both proven to induce PQBP1 to mediate cellular inflammation. In the current study, we revealed through qRT‒PCR, ELISA and Western blotting methods that PQBP1 plays a positive role in ARV-induced inflammation. Furthermore, the mechanism of this process was shown to involve the NFκB-dependent transcription of inflammatory genes. In addition, PQBP1 was shown to regulate the phosphorylation of p65 protein. In conclusion, this research provides clues to elucidating the function of the p17 protein and the pathogenic mechanism of ARV, especially the cause of the inflammatory response. It also provides new ideas for the study of therapeutic targets of ARV.

Overexpression of IκB⍺ modulates NF-κB activation of inflammatory target gene expression.

Cells respond to inflammatory stimuli such as cytokines by activation of the nuclear factor-κB (NF-κB) signalling pathway, resulting in oscillatory translocation of the transcription factor p65 between nucleus and cytoplasm in some cell types. We investigate the relationship between p65 and inhibitor-κB⍺ (IκBα) protein levels and dynamic properties of the system, and how this interaction impacts on the expression of key inflammatory genes. Using bacterial artificial chromosomes, we developed new cell models of IκB⍺-eGFP protein overexpression in a pseudo-native genomic context. We find that cells with high levels of the negative regulator IκBα remain responsive to inflammatory stimuli and maintain dynamics for both p65 and IκBα. In contrast, canonical target gene expression is dramatically reduced by overexpression of IκBα, but can be partially rescued by overexpression of p65. Treatment with leptomycin B to promote nuclear accumulation of IκB⍺ also suppresses canonical target gene expression, suggesting a mechanism in which nuclear IκB⍺ accumulation prevents productive p65 interaction with promoter binding sites. This causes reduced target promoter binding and gene transcription, which we validate by chromatin immunoprecipitation and in primary cells. Overall, we show how inflammatory gene transcription is modulated by the expression levels of both IκB⍺ and p65. This results in an anti-inflammatory effect on transcription, demonstrating a broad mechanism to modulate the strength of inflammatory response.

Investigating respiratory simplification caused by prenatal RAGE upregulation

Receptors for advanced glycation end-products (RAGE) are multi-ligand cell surface receptors of the immunoglobulin superfamily predominantly expressed by lung epithelium. Previous experiments showed that RAGE upregulation throughout pregnancy caused significant fetal lung hypoplasia via elevated apoptosis and misregulation of the transcription factors thyroid transcription factor 1 (TTF1) and forkhead box protein A2 (Fox-A2). Our current research focused on characterizing the contributors to these abnormalities. We confirmed poor development of murine lungs through a time course of RAGE upregulation from conception to sacrifice on embryonic day (E)15.5, E16.5, E17.5, E18.5, and specific upregulation from E15.5 to E18.5 only. H&amp;E staining confirmed significant simplification. We hypothesized that this malformation was in part due to aberrant levels of inflammation and apoptosis. Blotting revealed significantly increased levels of phosphorylated AKT and ERK1/2 in RAGE TG pups which cause NF-κB mediated transcription of inflammatory genes. Due to potential roles for these signaling intermediates, we sought to assess RAGE-mediated impact on mitochondrial efficiency. Oxidative phosphorylation was assessed in lungs from RAGE TG pups and controls by measuring oxygen consumption per unit mass when lungs were exposed to the substrates malate, glutamate, ADP, succinate, and FCCP which activate sequential components of the electron transport chain. We discovered significantly increased levels of oxidative phosphorylation in transgenic pups compared to controls. Levels of ATP and reactive oxidative species (ROS) in relation to altered oxidative phosphorylation and inflammation provided additional mechanistic clarity. These results support the importance of proper RAGE regulation in the development of lung tissue and elucidate mechanisms possibly causing such damage. This work was supported by funding from the National Institutes of Health (NIH 1R15-HL152257, PRR and JAA). This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.