Early Inflammatory Response Research Articles

Altered early immune response after fracture and traumatic brain injury.

Clinical and preclinical data suggest accelerated bone fracture healing in subjects with an additional traumatic brain injury (TBI). Mechanistically, altered metabolism and neuro-endocrine regulations have been shown to influence bone formation after combined fracture and TBI, thereby increasing the bone content in the fracture callus. However, the early inflammatory response towards fracture and TBI has not been investigated in detail so far. This is of great importance, since the early inflammatory phase of fracture healing is known to be essential for the initiation of downstream regenerative processes for adequate fracture repair. Therefore, we analyzed systemic and local inflammatory mediators and immune cells in mice which were exposed to fracture only or fracture + TBI 6h and 24h after injury. We found a dysregulated systemic immune response and significantly fewer neutrophils and mast cells locally in the fracture hematoma. Further, local CXCL10 expression was significantly decreased in the animals with combined trauma, which correlated significantly with the reduced mast cell numbers. Since mast cells and mast cell-derived CXCL10 have been shown to increase osteoclastogenesis, the reduced mast cell numbers might contribute to higher bone content in the fracture callus of fracture + TBI mice due to decreased callus remodeling.

Predicting the Next Superspreader.

The spread of multidrug-resistant zoonotic pathogens, such as Salmonella, within livestock is of concern for food safety. The spread of Salmonella on the farm is escalated by superspreaders, which shed the pathogen at high numbers with their feces. However, there are currently no biomarkers to identify potential superspreaders. Kempf and coworkers determined that a potent early inflammatory response to Salmonella infection and changes in the microbiota composition are associated with the superspreader phenotype in pigs (F. Kempf, G. Cordoni, A.M. Chaussé, R. Drumo, et al., mSystems, in press, https://doi.org/10.1128/msystems.00852-22). Since these biomarkers only develop during Salmonella infection, additional work is needed to predict animals that have the potential to become superspreaders.

The Role of Myeloperoxidase in Clozapine-Induced Inflammation: A Mechanistic Update for Idiosyncratic Drug-Induced Agranulocytosis.

The risk of idiosyncratic drug-induced agranulocytosis (IDIAG) markedly constrains the use of clozapine, a neuroleptic with unparalleled efficacy. Most clozapine patients experience an early inflammatory response, likely a necessary step in IDIAG onset. However, most patients do not progress to IDIAG, presumably because of the requirement of specific human leukocyte antigen (HLA) haplotypes, T cell receptors, and other unknown factors. We established that clozapine activates inflammasomes and that myeloperoxidase bioactivation of clozapine generates neoantigens, but the connection between these early mechanistic events remained unknown and, thus, was the aim of this work. We found that the myeloperoxidase inhibitor PF-1355 attenuated myeloperoxidase activity in phorbol myristate acetate (PMA)-differentiated THP-1 macrophages, and it also attenuated clozapine-induced release of inflammatory mediators (e.g., IL-1β, CXCL1, and C-reactive protein). In vivo, pretreatment of Sprague Dawley rats with PF-1355 significantly attenuated clozapine-induced increases in neutrophil mobilization from the bone marrow to the blood and spleen, as determined using differential blood counts and flow cytometry. Moreover, the clozapine-triggered release of inflammatory mediators (e.g., IL-1β, calprotectin, CXCL1, and α-1-acid glycoprotein) from the liver, spleen, and bone marrow was dampened by myeloperoxidase inhibition. These data support the working hypothesis that oxidation of clozapine to a reactive metabolite by myeloperoxidase is critical for induction of the inflammatory response to clozapine. Ultimately, a better mechanistic understanding of the early events involved in the immune response to clozapine may elucidate ways to prevent IDIAG, enabling safer, more frequent therapeutic use of this and potentially other highly efficacious drugs.

Osteo-Immunomodulatory Role of Interleukin-4-Immobilized Plasma Immersion Ion Implantation Membranes for Bone Regeneration.

Barrier membranes for guided tissue regeneration are essential for bone repair and regeneration. The implanted membranes may trigger early inflammatory responses as a foreign material, which can affect the recruitment and differentiation of bone cells during tissue regeneration. The purpose of this study was to determine whether immobilizing interleukin 4 (IL4) on plasma immersion ion implantation (PIII)-activated surfaces may alter the osteo-immunoregulatory characteristics of the membranes and produce pro-osteogenic effects. In order to immobilize IL4, polycaprolactone surfaces were modified using the PIII technology. No discernible alterations were found between the morphology before and after PIII treatment or IL4 immobilization. IL4-immobilized PIII surfaces polarized macrophages to an M2 phenotype and mitigated inflammatory cytokine production under lipopolysaccharide stimulation. Interestingly, the co-culture of macrophages (on IL4-immobilized PIII surfaces) and bone marrow-derived mesenchymal stromal cells enhanced the production of angiogenic and osteogenic factors and triggered autophagy activation. Exosomes produced by PIII + IL4-stimulated macrophages were also found to play a role in osteoblast differentiation. In conclusion, the osteo-immunoregulatory properties of bone materials can be modified by PIII-assisted IL4 immobilization, creating a favorable osteoimmune milieu for bone regeneration.

Comparison of Leukocyte-Rich and Leukocyte-Poor Platelet-Rich Plasma on Pressure Ulcer in a Rat Model.

Pressure ulcer (PU) is a common type of chronic wound that is difficult to treat. Platelet-rich plasma (PRP) is rich in cytokines and growth factors, and it can be divided into two categories according to its leukocyte content: leukocyte-poor PRP (P-PRP) and leukocyte-rich PRP (L-PRP). PRP has been applied in a variety of wound treatments, due to its strong ability to promote repair. This study aims to investigate the therapeutic effects of PRP on PU and elucidate the role of leukocytes in the treatment process. Sprague-Dawley rats were used to establish PU models of ischemia-reperfusion injury by applying magnets externally. L-PRP, P-PRP, and saline were injected into the dermal wounds. Wound healing analysis and sampling were performed on days 3, 7, 11, and 15 after treatment. Histological examinations, real-time PCR, immunohistochemical examinations, and biomechanical assay were carried out on the wound samples. The PRP groups exhibited greater wound inflammatory response than the control group in the early stage but the response reduced rapidly as the wound healed. On days 7, 11, and 15, the PRP groups also yielded better wound healing rates and histological outcomes than the control group, with superior biomechanical properties observed on day 15. Among both PRP groups, the L-PRP group attained a higher wound healing rate than the P-PRP group on day 7, with greater significant early inflammatory responses, and more prominent angiogenesis. Therefore, PRP is proven to accelerate the healing of PU, with L-PRP being more effective in regulating inflammation and promoting angiogenesis than P-PRP.

Integrin CD11b Contributes to Hypertension and Vascular Dysfunction Through Mediating Macrophage Adhesion and Migration.

Leukocyte adhesion to endothelium is an early inflammatory response and is mainly controlled by the β2-integrins. However, the role of integrin CD11b/CD18 in the pathogenesis of hypertension and vascular dysfunction is unclear. Hypertension was established by angiotensin II (490 ng/kg·per min) or deoxycorticosterone acetate salt. Hypertensive responses were studied in CD11b-deficient (CD11b-/-) mice, bone marrow transplanted and wild-type (WT) mice that were administered anti-CD11b neutralizing antibody or agonist leukadherin-1. Blood pressure was monitored with tail-cuff method and radiotelemetry. Blood and vascular inflammatory cells were assessed by flow cytometry. Aortic remodeling and function were examined using histology and aortic ring analysis. Cell adhesion and migration were evaluated in vitro. The relationship between circulating CD11b+ immune cells and hypertension was analyzed in patients with hypertension. We found that CD11b and CD18 expression as well as the CD45+CD11b+CD18+ myeloid cells were highly increased in the aorta of angiotensin II-infused mice. Ablation or pharmacological inhibition of CD11b in mice significantly alleviated hypertension, aortic remodeling, superoxide generation, vascular dysfunction, and the infiltration of CD11b+ macrophages through reducing macrophage adhesion and migration. These effects were confirmed in WT mice reconstituted with CD11b-deficient bone marrow cells. Conversely, angiotensin II-induced hypertensive response was exacerbated by CD11b agonist leukadherin-1. Notably, circulating CD45+CD11b+CD18+ myeloid cells and the ligand levels in hypertensive patients were significantly higher than in normotensive controls. We demonstrated a critical significance of CD11b+ myeloid cells in hypertension and vascular dysfunction. Targeting CD11b may represent a novel therapeutic option for hypertension.

Prevention of Bleomycin-Induced Pulmonary Inflammation and Fibrosis in Mice by Bilobalide.

Idiopathic pulmonary fibrosis (IPF) is a fatal interstitial lung disease. Bilobalide (BB) is a sesquiterpene isolated from Ginkgo biloba, and its role in IPF is poorly understood. Mice were intratracheally instilled with 2.5 mg/kg bleomycin (BLM) to induce IPF and then treated with 2.5, 5, and 10 mg/kg BB daily for 21 days. Treatment with BB ameliorated pathological injury and fibrosis of lung tissues in BLM-induced mice. BB suppressed BLM-induced inflammatory response in mice as demonstrated by reduced inflammatory cells counts (leukocytes, neutrophils, macrophages, and lymphocytes) and pro-inflammatory factors (CCL2 and TNF-α), as well as increased CXCL10 levels in BALF. The expression of BLM-induced hydroxyproline, LDH, and pro-fibrotic mediators including fibronectin, collagen I, α-smooth muscle actin (α-SMA), transforming growth factor (TGF)-β1, matrix metalloproteinase (MMP)-2, and MMP-9 in lung tissue was inhibited by BB treatment, and the tissue inhibitor of metalloproteinase-1 (TIMP-1) expression was increased. BB blocked the phosphorylation of JNK and NF-κB, and the nuclear translocation of NF-κB in the lung tissue of mice induced by BLM. Additionally, it abated the activation of NLRP3 inflammasome in lung tissue induced by BLM, which led to the downregulation of IL-18 and IL-1β in BALF. Our present study suggested that BB might ameliorate BLM-induced pulmonary fibrosis by inhibiting the early inflammatory response, which is probably via the inhibition of the JNK/NF-κB/NLRP3 signal pathway. Thus, BB might serve as a therapeutic potential agent for pulmonary inflammation and fibrosis.

Sequential intervention of anti-inflammatory and osteogenesis with silk fibroin coated polyethylene terephthalate artificial ligaments for anterior cruciate ligament reconstruction.

Graft-host integration after the anterior cruciate ligament (ACL) reconstruction sequentially follows the prognosis from the inflammation period to the regeneration period. However, due to insufficient bioactivity, polyethylene terephthalate (PET) artificial ligaments often require a long period for graft-host integration. To improve graft-host integration, sequential therapy targeting multifactor is widely advocated. In this study, a multilayer regenerated silk fibroin (RSF) coating loaded with heparin and bone morphogenetic protein binding peptide (BBP) for differentiated release was introduced on the surface of the PET artificial ligament by a stepwise deposition method. The drug release profiles of heparin and BBP on the coated PET artificial ligament indicated the features of differential drug release, i.e., with heparin in the outermost layer releasing a significant amount (more than 60%) during the first 5 days while BBP in the inner layer only releasing a small amount (ca. 30%) within 1 week without burst release. Based on the isometric ACL reconstruction model of rabbits, such drug-loaded RSF coating was verified to be able to modulate the early inflammatory response and promote the maturation of the graft in the articular cavity, meanwhile, it provided a continuous and stable signal of osteogenic induction to improve graft-bone integration. Thus, sequential intervention with heparin and BBP proved to be a reliable combination, and multifunctional RSF-coated PET artificial ligaments hold great potential for improving the clinical efficacy of ACL reconstruction.

The Use of Hydroxyapatite Loaded with Doxycycline (HADOX) in Dentoalveolar Surgery as a Risk-Reduction Therapeutic Protocol in Subjects Treated with Different Bisphosphonate Dosages.

Medication-related osteonecrosis of the jaw (MRONJ) is considered as a severe adverse side effect of specific drugs such as anti-resorptive and anti-angiogenic medications. Evidence suggests that MRONJ is linked to invasive dental procedures, mainly dentoalveolar surgery. Several preventive strategies to minimize the risk of developing MRONJ have been investigated. However, no investigation has been attempted to evaluate the therapeutic effect of local drug-delivery technology as a preventive strategy protocol. The aim of this study is to evaluate the efficacy of hydroxyapatite-containing doxycycline (HADOX) in rats with high-risk MRONJ development. All the rats used in this study were divided into seven groups. Six groups of rats out of seven were exposed to two different doses of antiresorptive drug therapy for four weeks before undergoing an upper incisor extraction. After 28 days, all the animals were euthanized, and the bone blocks were processed for histological and histomorphometrical evaluation. The histomorphometric analysis confirmed that newly formed bone (NFB) was present in all groups, with significant differences. NFB in the HADOX group treated with zoledronic acid at 4% showed (28.38; C.I. 22.29-34.48), which represents a significant increase compared to HA (15.69; C.I. 4.89-26.48) (p = 0.02). A similar pattern was observed in the HADOX group treated with zoledronic acid 8% ZA treatment (p = 0.001). Conclusions: HADOX did not inhibit any bone repair and reduced early inflammatory response. Hence, HADOX could promote bone healing in patients undergoing antiresorptive drug therapy.

NLRP3 inflammasome activation in neutrophils directs early inflammatory response in murine peritonitis.

NLR family pyrin domain containing 3 (NLRP3) inflammasome mediates caspase-1-dependent processing of inflammatory cytokines such as IL-1β, an essential endothelial activator, and contributes to the pathology of inflammatory diseases. To evaluate the role of NLRP3 in neutrophils in endothelial activation, which is still elusive, we used the thioglycollate-induced peritonitis model characterized by an early neutrophil influx, on Nlrp3-/- and Nlrp3+/+ mice. Nlrp3-/- mice recruited fewer neutrophils than Nlrp3+/+ into the peritoneum and showed lower IL-1β in peritoneal lavage fluid. The higher production of IL-1β in Nlrp3+/+ was neutrophil-dependent as neutrophil depletion prevented the IL-1β production. The Nlrp3+/+ neutrophils collected from the peritoneal fluid formed significantly more filaments (specks) than Nlrp3-/- neutrophils of ASC (apoptosis-associated speck-like protein containing a caspase activating and recruitment domain), a readout for inflammasome activation. Intravital microscopy revealed that leukocytes rolled significantly slower in Nlrp3+/+ venules than in Nlrp3-/-. Nlrp3-/- endothelial cells isolated from mesenteric vessels demonstrated a lower percentage of P-selectin-positive cells with lower intensity of surface P-selectin expression than the Nlrp3+/+ endothelial cells evaluated by flow cytometry. We conclude that neutrophils orchestrate acute thioglycollate-induced peritonitis by producing IL-1β in an NLRP3-dependent manner. This increases endothelial P-selectin expression and leukocyte transmigration.

MyD88-TLR4-dependent choroid plexus activation precedes perilesional inflammation and secondary brain edema in a mouse model of intracerebral hemorrhage.

The functional neurological outcome of patients with intracerebral hemorrhage (ICH) strongly relates to the degree of secondary brain injury (ICH-SBI) evolving within days after the initial bleeding. Different mechanisms including the incitement of inflammatory pathways, dysfunction of the blood-brain barrier (BBB), activation of resident microglia, and an influx of blood-borne immune cells, have been hypothesized to contribute to ICH-SBI. Yet, the spatiotemporal interplay of specific inflammatory processes within different brain compartments has not been sufficiently characterized, limiting potential therapeutic interventions to prevent and treat ICH-SBI. We used a whole-blood injection model in mice, to systematically characterized the spatial and temporal dynamics of inflammatory processes after ICH using 7-Tesla magnetic resonance imaging (MRI), spatial RNA sequencing (spRNAseq), functional BBB assessment, and immunofluorescence average-intensity-mapping. We identified a pronounced early response of the choroid plexus (CP) peaking at 12-24h that was characterized by inflammatory cytokine expression, epithelial and endothelial expression of leukocyte adhesion molecules, and the accumulation of leukocytes. In contrast, we observed a delayed secondary reaction pattern at the injection site (striatum) peaking at 96h, defined by gene expression corresponding to perilesional leukocyte infiltration and correlating to the delayed signal alteration seen on MRI. Pathway analysis revealed a dependence of the early inflammatory reaction in the CP on toll-like receptor 4 (TLR4) signaling via myeloid differentiation factor 88 (MyD88). TLR4 and MyD88 knockout mice corroborated this observation, lacking the early upregulation of adhesion molecules and leukocyte infiltration within the CP 24h after whole-blood injection. We report a biphasic brain reaction pattern after ICH with a MyD88-TLR4-dependent early inflammatory response of the CP, preceding inflammation, edema and leukocyte infiltration at the lesion site. Pharmacological targeting of the early CP activation might harbor the potential to modulate the development of ICH-SBI.

ALA-PDT regulates macrophage M1 polarization via ERK/MAPK-NLRP3 pathway to promote the early inflammatory response.

Photodynamic therapy (PDT) is a promising new approach to promote wound healing and its effectiveness has been demonstrated in both clinical and animal studies. Macrophages are the key cells in wound healing and inflammatory response. However, the mechanism of action of PDT on macrophages in promoting wound healing is still unclear. In this study, RAW264.7 cells were used. We analyzed the expression levels of macrophage markers arginase 1 (Arg-1), CD206, iNOS, CD86, and inflammatory factors IL-6, TNF-α, andIL-1β by reverse transcription-polymerase chain reaction and Western blot, Milliplex microtubule-associated protein multiplex assay was performed to analyze the expression of inflammatory factors in the supernatant. Live cell Imaging System to observe the dynamic process of macrophage phagocytosis. Western blot was performed to observe the activation of extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK) and NOD-like receptor protein 3 (NLRP3) inflammasome. 5-Aminolevulinic acid (ALA)-PDT increased the expression of M1 marker iNOS/CD86 and decreased the expression of Arg-1/CD206 in RAW264.7 cells, while, proinflammatory factors IL-6, TNF-α, and IL-1β expression was enhanced and macrophage phagocytosis was increased. We also found that these phenomena were associated with activation of the ERK/MAPK-NLRP3 pathway. ALA-PDT promotes early inflammatory responses by regulating macrophage M1 polarization through the ERK/MAPK-NLRP3 pathway. It also promotes macrophage phagocytosis.

Abstract 15181: PET/CT Imaging for Evaluating Inflammation in Rapamycin Coated Tissue-Engineered Arterial Grafts Implanted in an Ovine Model

Introduction: Small diameter tissue-engineered arterial grafts (TEAGs) conjugated with rapamycin may improve TEAG outcomes by reducing early post-implant inflammatory responses, thereby improving rates of TEAG patency. Therefore, the objective of this study was to apply in vivo PET/CT imaging to compare inflammation and patency of TEAGs conjugated with or without rapamycin. We hypothesized that rapamycin-coated TEAGs would have reduced inflammation and improved patency rates that could be evaluated during a single imaging session using 18 F-FDG PET/CT imaging. Methods: Rapamycin coated (n=3) and non-rapamycin coated (n=3) TEAGs were unilaterally implanted in the carotid artery of juvenile lambs. Flourine-18 ( 18 F)-fluorodeoxyglucose (FDG) PET/CT imaging was performed 8 weeks after TEAG implantation to quantify inflammation of the graft, which was expressed as the maximum standardized uptake value (SUV max ) in the graft. Graft patency was assessed using co-registered CT angiography imaging. In vivo PET/CT imaging results were further evaluated by ex vivo gamma counting of 18 F-FDG uptake in TEAG tissue. Results: In vivo PET/CT detected qualitative and quantitative differences in inflammation between non-drug coated and drug coated TEAGs (SUV max : 6.18±1.67 vs, 4.25±0.81; p=0.1). Differences in inflammation between groups were significant when evaluating results of ex vivo gamma counting of 18 F-FDG uptake (% Injected dose/g: 0.86±0.10 vs, 0.50±0.010; p=0.003). Additionally, CT angiography demonstrated that all rapamycin-coated TEAGs were patent (3/3) at 8 weeks post-implant whereas only one non-drug coated TEAG remained patent (1/3). Conclusions: Conjugation of TEAGs with rapamycin prevents excessive inflammation in the early months after implantation and maintains graft patency. PET/CT offers a translatable imaging approach that allows for combined in vivo assessment of the functional and anatomical characteristics of TEAGs and may assist in optimizing scaffold design for next-generation TEAGs.

Effects of Dexmedetomidine on Systemic Inflammation and Postoperative Complications in Laparoscopic Pancreaticoduodenectomy: A Double-blind Randomized Controlled Trial

BackgroundLaparoscopic pancreaticoduodenectomy (LPD) may induce intense inflammatory response which might be related to the patient’s outcomes. Clinical dexmedetomidine (DEX) has been widely used for opioid-sparing anesthesia and satisfactory sedation. The objective of this study was to investigate the influence of DEX on inflammatory response and postoperative complications in LPD.MethodsNinety-nine patients undergoing LPD were randomly assigned to two groups: normal saline (NS) and DEX. The primary outcome was the neutrophil-to-lymphocyte ratio (NLR) differences postoperatively within 48 h. Secondary outcomes were postoperative complications, the length of postoperative hospital stay and the incidence of ICU admission. Other outcomes included anesthetics consumption and intraoperative vital signs.ResultsNLR at postoperative day 2 to baseline ratio decreased significantly in the DEX group (P = 0.032). Less major complications were observed in the DEX group such as pancreatic fistula, delayed gastric emptying and intra-abdominal infection (NS vs. DEX, 21.7% vs. 13.6%, P = 0.315; 10.9% vs. 2.3%, P = 0.226; 17.4% vs. 11.4%, P = 0.416, respectively) though there were no statistical differences. Three patients were transferred to the ICU after surgery in the NS group, while there was none in the DEX group (P = 0.242). The median postoperative hospital stay between groups were similar (P = 0.313). Both intraoperative propofol and opioids were less in the DEX group (P < 0.05).ConclusionsIntraoperative DEX reduced the early postoperative inflammatory response in LPD. It also reduced the use of narcotics that may related to reduced major complications, which need additional research further.

Role of Mesenchymal Stem Cells and Their Paracrine Mediators in Macrophage Polarization: An Approach to Reduce Inflammation in Osteoarthritis.

Osteoarthritis (OA) is a low-grade inflammatory disorder of the joints that causes deterioration of the cartilage, bone remodeling, formation of osteophytes, meniscal damage, and synovial inflammation (synovitis). The synovium is the primary site of inflammation in OA and is frequently characterized by hyperplasia of the synovial lining and infiltration of inflammatory cells, primarily macrophages. Macrophages play a crucial role in the early inflammatory response through the production of several inflammatory cytokines, chemokines, growth factors, and proteinases. These pro-inflammatory mediators are activators of numerous signaling pathways that trigger other cytokines to further recruit more macrophages to the joint, ultimately leading to pain and disease progression. Very few therapeutic alternatives are available for treating inflammation in OA due to the condition's low self-healing capacity and the lack of clear diagnostic biomarkers. In this review, we opted to explore the immunomodulatory properties of mesenchymal stem cells (MSCs) and their paracrine mediators-dependent as a therapeutic intervention for OA, with a primary focus on the practicality of polarizing macrophages as suppression of M1 macrophages and enhancement of M2 macrophages can significantly reduce OA symptoms.

Assessing Acute Cardiac Inflammation after Left-Sided Breast Cancer Radiotherapy with Hybrid PET/MRI (RICT-BREAST)

<h3>Purpose/Objective(s)</h3> The goal of this study is to investigate the utility of hybrid ¹⁸FDG PET/MRI and serial blood work to detect early inflammatory response and cardiac functionality changes at one-month and one-year post radiation therapy (RT) in patients with left-sided breast cancer. <h3>Materials/Methods</h3> Fifteen left-sided breast cancer patients are currently enrolled in the RICT-BREAST study (NCT03748030). Serial imaging with hybrid ¹⁸FDG PET/MRI and blood work was obtained at baseline (before RT), at one-month post RT, and at one-year post RT. The hybrid ¹⁸FDG PET/MR imaging protocol consisted of a sixty-minute list-mode ¹⁸FDG PET scan with prior glucose suppression. Myocardial inflammation was quantified by calculating the change of mean ¹⁸FDG standard uptake (meanSUV_bw) at 40-60 minutes post injection and was grouped based on the supplied artery (left anterior descending (LAD), left circumflex (LC) or right coronary artery (RCA)). MRI assessments, including left ventricle (LV) functional and extracellular volume matrices (ECV), were extracted from T1 (pre and during-constant infusion of gadolinium) and cine images, respectively, and acquired simultaneously during PET acquisition. Cardiac disease and inflammation biomarker measurements of high-sensitivity troponin T (hs-TnT), C-reactive protein (hs-CRP) and erythrocyte sedimentation rate (ESR) were compared at each timepoint. <h3>Results</h3> Eleven patients received deep-inspiration breath-hold RT (DIBH-RT), while four patients received free-breathing RT (FB-RT), where 4D-CT simulation was performed to define cardiac motion encompassment. To date, all patients have received hybrid ¹⁸FDG PET/MRI cardiac imaging and bloodwork at baseline and at one month after RT. Two patients have received their one-year follow-up ¹⁸FDG PET/MRI scan and bloodwork. At 1-month follow-up, a significant increase (10%) of ¹⁸FDG/PET myocardial uptake (meanSUV_bw) was detected at LAD territories (p = 0.04). A significant increase in mean ECV, measured with T1-mapping, was observed in slices of the apex (6%) and base (5%) were also detected (p < 0.02). A significant reduction of mean LV stroke volume (-7%) was also identified (p < 0.02). Insignificant changes of all blood work measurements at 1-month follow-up were reported. There was no detectable difference in any cardiac measure between patients who received DIBH-RT and FB-RT. For the two patients who had their one-year follow-ups, an increase in hs-CRP and ESR levels were detected compared to baseline, whereas global reduction of FDG uptake was seen. One patient had an increase of hs-TnT (up to 19ng/L) with left ventricle remodeling reported in echocardiography and a global increase of ECV. <h3>Conclusion</h3> ¹⁸FDG/PET myocardial uptake and functional MR, including SV and ECV were sensitive to changes at 1-month after breast cancer RT with findings suggesting an acute inflammatory response in the heart. One-year median follow-up imaging and bloodwork has been acquired for 2 of 15 patients thus far.

A system pharmacology Boolean network model for the TLR4-mediated inflammatory response in early sepsis

Sepsis is a life-threatening condition driven by the dysregulation of the host immune response to an infection. The complex and interacting mechanisms underlying sepsis remain not fully understood. By integrating prior knowledge from literature using mathematical modelling techniques, we aimed to obtain a deeper mechanistic insight into sepsis pathogenesis and to evaluate promising novel therapeutic targets, with a focus on Toll-like receptor 4 (TLR4)-mediated pathways. A Boolean network of regulatory relationships was developed for key immune components associated with sepsis pathogenesis after TLR4 activation. Perturbation analyses were conducted to identify therapeutic targets associated with organ dysfunction or antibacterial activity. The developed model consisted of 42 nodes and 183 interactions. Perturbation analyses suggest that over-expression of tumour necrosis factor alpha (TNF-α) or inhibition of soluble receptor sTNF-R, tissue factor, and inflammatory cytokines (IFN-γ, IL-12) may lead to a reduced activation of organ dysfunction related endpoints. Over-expression of complement factor C3b and C5b led to an increase in the bacterial clearance related endpoint. We identified that combinatory blockade of IFN-γ and IL-10 may reduce the risk of organ dysfunction. Finally, we found that combining antibiotic treatment with IL-1β targeted therapy may have the potential to decrease thrombosis. In summary, we demonstrate how existing biological knowledge can be effectively integrated using Boolean network analysis for hypothesis generation of potential treatment strategies and characterization of biomarker responses associated with the early inflammatory response in sepsis.

Sphingosine 1-phosphate receptor 2 mediated early stages of pancreatic and systemic inflammatory responses via NF-kappa B activation in acute pancreatitis

In acute pancreatitis, activation of inflammatory signaling, including the nuclear factor-kappa B (NF-κB) pathway, within acinar cells is known to be an early intracellular event occurring in parallel with pathologic trypsinogen activation. Sphingosine 1-phosphate receptor 2 (S1PR2) plays a critical role in endothelial inflammation, and our previous studies reported that S1PR2 deficiency significantly reduced the inflammatory response in liver injury under cholestasis conditions. However, the role of S1PR2 in inflammatory signaling activation within acinar cells and inflammatory responses during acute pancreatitis has not been elucidated. Here we report that S1PR2 was upregulated in the whole pancreas during acute pancreatitis. Blockade of S1PR2 by pharmacologic inhibition of S1PR2 by JTE-013 or AAV-mediated knockdown of S1PR2 improved the severity of pancreatic injury, as indicated by a significant reduction in inflammation and acinar cells death in acute pancreatitis mice. Moreover, S1PR2 is the predominant S1PRs expressed in pancreatic acinar cells and mediates NF-κB activation and the early inflammatory response within acinar cells under acute pancreatitis conditions via ROCK signaling pathways, not extracellular signal-regulated kinase pathways or p38 mitogen-activated protein kinase pathways. In addition, S1PR2 mediated macrophage NF-κB activation, migration and polarization toward the M1 phenotype. Therefore, these results demonstrated that the S1PR2-mediated early inflammatory response in acinar cells promotes the progression of acute pancreatitis, successfully linking local events to the systematic inflammatory response and leading to a novel therapeutic target for acute pancreatitis aimed at halting the progression of the inflammatory response.4Upw5czRUXogyYiQEsPybuVideo

LncRNA KCNQ1OT1 predicts further cerebral events in patients with transient ischemic attack.

Transient ischemic attack (TIA) poses a great threat of cerebrovascular diseases to a large number of patients, despite its reversible neurological dysfunction. Long non-coding RNAs (lncRNAs) have been proven to play critical roles in the pathophysiological development of cerebrovascular events. Exploring the function of lncRNAs in modulating TIA prognosis would help to develop individualized therapeutics. A total of 231 participants with the first onset of TIA were recruited in the study, including 65 subsequent stroke patients. The expression of lncRNA potassium voltage-gated channel subfamily Q member 1 opposite strand 1 (KCNQ1OT1) was upregulated in patients with recurrent ischemic events after TIA. Additionally, KCNQ1OT1 could be regarded as an independent predictor for subsequent ischemic stroke. The optimal diagnostic value was determined at 1.29 with a sensitivity of 63% and a specificity of 72%. Fewer patients would survive from further ischemic stroke with their KCNQ1OT1 level over 1.29. Furthermore, the expression of KCNQ1OT1 was elevated with a growing serum high-sensitivity C-reactive protein (hs-CRP) level. KCNQ1OT1 might be involved in the regulation of early inflammatory response during recurrence of TIA.

Effects of iNOS in Hepatic Warm Ischaemia and Reperfusion Models in Mice and Rats: A Systematic Review and Meta-Analysis.

Warm ischaemia is usually induced by the Pringle manoeuver (PM) during hepatectomy. Currently, there is no widely accepted standard protocol to minimise ischaemia-related injury, so reducing ischaemia-reperfusion damage is an active area of research. This systematic review and meta-analysis focused on inducible nitric oxide synthase (iNOS) as an early inflammatory response to hepatic ischaemia reperfusion injury (HIRI) in mouse- and rat-liver models. A systematic search of studies was performed within three databases. Studies meeting the inclusion criteria were subjected to qualitative and quantitative synthesis of results. We performed a meta-analysis of studies grouped by different HIRI models and ischaemia times. Additionally, we investigated a possible correlation of endothelial nitric oxide synthase (eNOS) and nitric oxide (NO) regulation with iNOS expression. Of 124 included studies, 49 were eligible for the meta-analysis, revealing that iNOS was upregulated in almost all HIRIs. We were able to show an increase of iNOS regardless of ischemia or reperfusion time. Additionally, we found no direct associations of eNOS or NO with iNOS. A sex gap of primarily male experimental animals used was observed, leading to a higher risk of outcomes not being translatable to humans of all sexes.